Proceedings Volume 6357

Sixth International Symposium on Instrumentation and Control Technology: Signal Analysis, Measurement Theory, Photo-Electronic Technology, and Artificial Intelligence

Jiancheng Fang, Zhongyu Wang
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Proceedings Volume 6357

Sixth International Symposium on Instrumentation and Control Technology: Signal Analysis, Measurement Theory, Photo-Electronic Technology, and Artificial Intelligence

Jiancheng Fang, Zhongyu Wang
View the digital version of this volume at SPIE Digital Libarary.

Volume Details

Date Published: 6 November 2006
Contents: 4 Sessions, 200 Papers, 0 Presentations
Conference: Sixth International Symposium on Instrumentation and Control Technology 2006
Volume Number: 6357

Table of Contents

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Table of Contents

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  • Signal Acquisition, Processing, and Analysis
  • Measurement Theory and Technology
  • Photo-Electronic Technology and Instrumentation
  • Artificial Intelligence, Network, and Fault Detection
Signal Acquisition, Processing, and Analysis
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A detection method of signal frequency based on optimization theory
Chunyan Nie, Yaowu Shi, Zhuwen Wang, et al.
The sensitive characteristic to initial value of chaos system and the immunity to noise sufficiently demonstrate the superiority in weak signal detection. In this paper Duffing equation is used as system detection model, on the basis of optimization theory, a most optimization searching method, which takes the variance of output X as the detected value is present. The basic principle and the theoretical algorithm about detecting the weak signal with this method are proposed. At the same time, the simulation experiments and the result analysis are given. The results indicated this method is rapidly, simple, convenient and the accuracy is high, which is a novel detecting frequency method. If this method were applied in signal processing field or other application field, it would have practical significance.
A new method to estimate 1/f signals
Xueyan Li, Shuxu Guo, Ye Li
The main conceptual aspect of this work is on 1/f signal estimate. In this paper a new estimation algorithm that bases on Dual-Tree Complex Wavelet is proposed, which uses the variance of the wavelet coefficients at different scales to estimate the parameters of 1/f process. Adopting Maximum Posteriori estimator estimates the wavelet coefficients of 1/f process. The simulation results show that the method is effective. And comparing with other methods this method doesn't need to know the statistical characteristic of the added white noise and the parameters of the 1/f process.
A quick solution of form error by MATLAB
Quanwei Wang, Xueyi Li, Dong Li
This article puts forward a new measurement of departures from straightness, flatness, roundness and cylindricity in order to conquer the defect of current method on efficiency and precision of data processing, an optimized mathematical model for departure calculation is established respectively. The value of form error is calculated rapidly and precisely on microcomputer by the powerful and optimized calculation function of MATLAB. The solution of departure is established according to minimum zone. It is applied to data processing for dense measurement point especially.
Research of multiscale morphological filter on low intensity x-ray image system
Tangren Dan, Zhenxing Wang, Xin Du, et al.
New structure low intensity x-ray image system is mainly made of a plane plate mode x-ray intensifier of single proximity focus, a CCD data acquisition and a processing subsystem. This paper presents noise source inside the x-ray image system and its characteristics. By analyzing its components, image noise source of the system is found to contain quantum noise, particulate noise and dark noise of CCD. Thus a new combination method of "multi-frame mean with morphological transform filter" is studied in this paper for imaging noise elimination in the low intensity x-ray image system. Firstly, some frames of images are superimposed for mean image calculation based on the principle of noise non-correlation. Secondly, different with traditional methods of morphological transform filtering algorithm, difference image information is referred in the algorithm for source image de-noising. Based on multi-scale morphological principle, the difference image, obtained from the source image, contains both image noise and characters. After subsequent processing of wavelet translation and fuzzy algorithm, the noise of the difference image is eliminated. Thus when the processed difference image is added onto the last filtered image by the multi-scale morphological filter, the advanced image without noise is achieved which still keeps the source image characters.
Study on recognition technology of complementary image
Chengxiang Liu, Xuejuan Hu, Yaobo Jian, et al.
Complementation image is often used as a guard technology in the trademark and paper currency. The key point of recognizing this kind of images is judging the complementary effect of complementation printing. The perspective images are usually not clear and legible, so it is difficult to recognize them. In this paper, a new method is proposed. Firstly, capture the image by reflex. Secondly, find the same norm to man-made pair printing. Lastly, judge the true and false of paper currency by the complementary effect of complementation printing. This is the purpose of inspecting the false. Theoretic analysis and simulation results reveal that the effect of man-made pair printing is good, the method has advantages such as simplicity, high calculating speed, and good robust to different RMB. The experiment results reveal that the conclusion is reasonable, and demonstrates that this approach is effective.
Comparison of three methods of waveform recovery in the presence of noise
Renxiao Qiao, Xiaofeng Meng, Yingying Wang
Three methods of waveform recovery for signals in the presence of noise are discussed in this paper. LIA (Lock-in Amplifier) is used to detect the DC signal or slowly varying signal with low SNR (signal noise ratio), the core part of which is PSD (phase sensitive detector). As a special case, the orthogonal vector LIA is discussed in detail, which is capable of vector analysis of signal. Sampling integral and digital average can recover the impulse waveform with rapid rising and roll-off edges, which have lots of harmonic components in the presence of noise. But many periods of signals are usually needed in this method. On the contrary, the correlation detection method is effective for waveform recovery of the periodical signal when signal of enough duration is not available. By simulation in Matlab, the effectiveness of digital average as well as correlation detection was verified in their specific application conditions.
Optimizing slip-mean-time used in estimating nonstationary random vibration signal's PSD
Feiyu Huang, Hongjie Yuan, Chuanri Li
The aircraft has always suffered non-stationary random vibration in the booster-phase of the launch process. Obtain the relationship between the slip-mean-time and the bias error and that between the slip-mean-time and the random error in the estimation of a non-stationary random vibration signal's power spectral density (PSD) by analyzing the estimation of the signal's variable mean square (MS). Based on this, Obtain the analytic relationship between the variable MS of a sample of a non-stationary random vibration signal and the optimum slip-mean-time which causes the smallest total error in the spectrum analysis of the signal, propose an approach for optimizing the slip-mean-time in the estimation of a non-stationary random vibration signal's PSD. Present an appliance for a signal sample of a random vibration process which is caused during an aircraft booster-phase. Used the orthogonal polynomial approximation to get the analytic format of the process's MS, confirm the optimum slip-mean-time used in estimating the signal's PSD.
Improvement of the EMD method and applications in defect diagnosis of ball bearings
Qiuhua Du, Shunian Yang
In this paper, the method of empirical mode decomposition is introduced and the arithmetic of empirical mode decomposition is improved. The local mean with the envelope method of the extrema is substituted by an improved method, in which the local mean is computed by using window average method. The improved arithmetic is described in detail and the simulating model to validate the improved method is also presented in the paper. The results show the improved method has decreased the times of spline interpolation and saved the decomposition time. Moreover, all the data has participated in the computation of the local mean, thus the data to be used is increased in the improved method. Based on the improved empirical mode decomposition method, the defects of ball bearings are diagnosed practically and the results show that the proposed method is more powerful than traditional envelope analysis.
Images matching based on a new gradient neural network
Yan Zhang, Hong-Yan Dong, Zhen-Kang Shen
Focusing on the searching strategy in image matching, this paper constructs an energy function with features of a convex function based on Lyapunov Stability Theorem. It thus enables the Gradient neural network to converge steadily into the set of critical points of the target function. Then this paper tries to apply the network in image matching with moment invariants as the feature parameter. The specific steps of the experiments are supplied in this paper. According to the results of the experiments, this matching algorithm features good convergence, high speed, wide applicability and an extraordinary matching effect.
Vector predictive coding algorithm for unstable speech signal sequences
Zhengxiang Qian, Luyi Yang, Wei Chen, et al.
In vector predictive coding of speech signal sequences, the speech vector sequences that is obtained after a classification of adjacent sample of source speech sequences, can be regarded as autoregressive vector sequences with stable convariance. The vector predictive coding algorithm with highly parallel processing ability, can be achieved with the application of the principle of orthogonal projection in Hilbert space. In comparison with traditional lattice methods, the vector predictive coding algorithm has obvious advantages of calculating complexity and storage.
Long-range target detection algorithms in sea and sky clutter background based on fractal theory
Junjie Zheng, Xiaoke Yan, Caicheng Shi
A novel algorithm for the detection of long-range weak targets in a sea and air scenario is proposed. A preprocessing model of weak targets in sea and sky clutter background is established based on fractal theory, which is accordant to the concept that singular local fractal dimension (LFD) will be determined at edges. The model is evaluated by comparing row-mean subtraction filter based on fractal dimension preprocessing with conventional operators such as, high pass filter and row-mean subtraction filter. Results show a similar performance in a low-noise environment and superiority of the fractal operators in a high noise and long range dim targets, the algorithms are effectively for suppression sea and sky clutter and are easy to be implemented by parallel processing hardware.
Blind image restoration algorithm based on adaptive decision feedback equalizer
Jie Jiang, Bo Lv, Guangjun Zhang
Adaptive decision feedback equalizer (ADFE) derived from transverse equalizer uses decision output signal to form a delay line, through which parts of coefficients are added together and are returned to the output. ADFE can compensate for communication channels with severe inter-symbol interference. The blur on image can be regarded as perturbation of the pixels, so in this paper a kind of ADFE is applied to 2D image restoration. There are two adaptive filers in this method, the forward filter has more flexibility to select its coefficients and is not direct inverse of blur transfer function. As a result, noise amplify will not happen. Additionally, the support of the object is determined with threshold. The experiments show that this new algorithm is robust and effectively when existing additive noise.
Image denoising using a directional adaptive diffusion filter
Cuifang Zhao, Caicheng Shi, Peikun He
Partial differential equations (PDEs) are well-known due to their good processing results which it can not only smooth the noise but also preserve the edges. But the shortcomings of these processes came to being noticed by people. In some sense, PDE filter is called "cartoon model" as it produces an approximation of the input image, use the same diffusion model and parameters to process noise and signal because it can not differentiate them, therefore, the image is naturally modified toward piecewise constant functions. A new method called a directional adaptive diffusion filter is proposed in the paper, which combines PDE mode with wavelet transform. The undecimated discrete wavelet transform (UDWT) is carried out to get different frequency bands which have obviously directional selectivity and more redundancy details. Experimental results show that the proposed method provides a performance better to preserve textures, small details and global information.
A novel method of dynamic target detection
Lingjia Gu, Shuxu Guo, Ruizhi Ren, et al.
The shooting range test is an important field in modern weapon development. The modern weaponry is developing towards long distance and automation directions, therefore the shooting range test is put forward new higher requirements. A novel method of target detection based on the digital image processing technology is proposed in the paper. Experiments indicate the strategy is fit to the request of the dynamic target detection and tracking in the shooting range.
Spatial filtering method for fringe patterns based on gray gradient
Mingzhao Zhang, Boxiong Wang, Xiuzhi Luo, et al.
Traditional spatial filtering methods such as median filtering and mean filtering are widely used to remove additive noise in images. Images smoothed using these methods are inevitably blurred. If images are fringe patterns and filtering mask used is in fixed shape, such as a rectangle of mxn pixels, the structures of the pattern processed may be even deformed. To resolve this problem, a filtering method with varying mask based on gray gradient is proposed. This method makes full use of the feature of fringe patterns in that the gradient of gray level at a pixel is normal to the tangential direction of the fringe there. According to the method, gradient vector at a pixel is calculated first, and then the shape of the filtering mask to be used is determined based on the gradient vector. If its amplitude is smaller than a predefined value, a nxn square mask is used, on the other hand, if its amplitude is larger than the predefined value, a bar mask normal to the vector is used. Finally, the median value or mean value of the pixels in the mask is then achieved as the smoothed value of the pixel. After the same operations are applied to all pixels in the pattern sequentially, the smoothed version of the fringe pattern is achieved. A simulated fringe pattern with noise is smoothed using this method and other filtering methods for comparison, and the result shows that noise in the fringe pattern can be effectively removed and the characteristic details of the fringes can be reserved at the same time.
A multifocus image fusion new method based on multidecision
Yajie Wang, Xinhe Xu
A novel method of multi-decision of multi-focus image fusion on the basis of wavelet transform is presented for the sake of standing out clear characteristics and keeping detail information of original images. Low frequency part utilizes definition whose evaluating function is sum of Laplacian operator in the eight directions. High frequency parts utilize spatial frequency, which is calculated only one direction that is the same as high frequency direction, whose method decreases workload. Besides the traditional evaluating measures of fused image quality, which are entropy and cross entropy, the newest universal measures which combines objective and subjective factors, and the spatial frequency presented by this paper based on three directions which are horizontal, vertical and diagonal, are also used. These evaluating methods don't require a reference image. The experimental results show that the fused image obtained by proposed method has good effect, and the proposed method is superior to the other given algorithms.
Study on the FOG's signal based on wavelet
Ji-qiang Tang, Jian-cheng Fang, Yan-shun Zhang
In order to study on the fiber optical gyro (abbreviated as FOG) signal based on wavelet, this paper researches the FOG signal drift model and the properties of wavelet analyzed noise, introduces the wavelet filtering method, wavelet base selection, soft and hard threshold value de-noising algorithm and compulsive filtering based on The Haar wavelet. These threshold value filtering results of both of the soft and of the hard threshold value for the same wavelet base of db4 with the same Donoho threshold values and these results of compulsive filtering based on The Haar wavelet and db4 wavelet are presented also in this paper and then these main conclusions based on foregoing analysis are reached: Larger the resolving scale is, the filtering effect is more perfect. The soft threshold value filtering effect is better than that of the hard threshold value filtering at the cost of calculation when the threshold value is same. The zero shift of the compulsive filtering is least when both the wavelet and the resolving scale are same for these filtering methods. For the compulsive filtering with same wavelets, the filtering effect of Harr is better than that of db4 and the calculation of the former is fewer. Finally the author point out that applying the compulsive filtering with the Harr wavelet base and suitable resolving scale to the signal processing of FOG be helpful for the FOG's design and manufacturing.
Balanced log-domain wavelet filters
Hong-min Li, Yi-gang He
To meet the ultra low-power and low-voltage applications,this paper presents a analog VLSI implementation of DOG wavelet transform using a balanced log-domain integrator with class AB. The circuits of implementing wavelet transform are composed of analog filter ,whose impulse response is the required wavelet . Levenbery-Marquardt nonlinear least square method is employed to obtain the transfer function of the filter.The filter design is based on IFLF structure with balanced log-domain integrators as the main building blocks.By changing the values of the log-domain integrators bias currents, this circuit can realize various scales wavelet transform. And the validity of the proposed method is confirmed by Pspice simulation results.
Spatially adaptive context-based wavelet shrinkage for borescope image denoising
Peng Ding, Qi Shuang Ma, Chang You Li, et al.
Using borescope equipment to inspect the inside of turbine engines is an important technology to the daily damage detection of aeronautic engine. Because the borescope image that we observe is based upon point light, and the quantum nature of light is not ideal enough, borescope image acquired through charge-coupled device (CCD) is contaminated by white Gaussian noise. Towards this, a kind of spatially adaptive context-based wavelet shrinkage borescope image denoising method was presented. The spatially adaptive wavelet thresholding was selected based on context modeling, which was used in our prior borescope image compression coder to adapt the probability. Each wavelet coefficient was modeled as a Gibbs field distribution. Context modeling was used to estimate the thresholding for each coefficient. This method was based on an overcomplete non-subsampled wavelet representation, which yielded better results than the orthogonal transform. Experimental results show that spatially adaptive wavelet thresholding yields significantly improved visual quality as well as lower mean squared error (MSE) compared to the method of Chang.
Detection and removal of inveracious edges of shadows based on wavelet transform
Changyou Li, Hongyu Yao, Qishuang Ma
An algorithm of detection and removal for the inveracious edge of shadow in borescope images based on wavelet transform is presented. Because inveracious edges which shadows result in will influence the validity of subsequent image recognition, it is necessary to remove those inveracious edges that are extracted directly from borescope images. The grey levels of shadow regions in borescope images are low and uniform. Therefore, contours of shadows are step-structure borders. Thus, the algorithm first extracts all the edges from image using dyadic wavelet transform at multiscale. Further, the borders of shadow regions are detected from all the edges by using the property that the wavelet coefficients of step-structure borders are not correlative to the scales of wavelet transform, and connected. Finally, a neighborhood function is constructed to recognize and remove those pixels on the inveracious border. Experiment results show that this algorithm can directly obtain the intrinsical edges.
Processing of x-ray image in the intelligent setting system for fracture
Wei Zheng, Liyong Zhang, Sijiu Liu, et al.
Intelligent setting system based on biomechanics and bone fracture therapy can accomplish micro-wound, intelligence and high efficiency of fracture setting. X-ray images grabbed by C-shape-arm X-ray machine supply the most key data for intelligent setting. Processing, analysis and transmission security of the image is the core in the system. According to characteristics being shown in three dimensions gray distribution figure and frequency spectrum of the image, histogram equalization in space domain and homomorphic filtering in frequency domain are separately proposed to enhance contrast and sharpness. On the foundation of mining orthopedics experts experience knowledge, setting for femoral-neck fracture is turned into three in-continuous operations that are reflected in the X-ray images through nine points, six lines, two angles and one distance and that are able to be implemented by mechanical manipulator and control device in the system. Master-slave reference frame is put forward to supply a stable reference standard to calculate parameters. Encryption method based on chaos dynamics system is brought forward to ensure image information security in the process of telemedicine intelligent setting for fracture. Clinic experience proved that the system can help orthopedists to correctly and reliably complete setting for bone fracture.
3D profilometry system based on absolute phase calibration
Hao Yu, Shuangyun Shao, Zhifeng Zhang, et al.
Improvement of absolute phase calibration in phase-measuring profilometry is presented. In order to calculate the absolute phase of calibration plane, linear interpolation of unwrapping phase of reference point is introduced. Accuracy of height calibration and measurement is improved. A novel 3D surface shape measurement system is designed. Experiments of given height plane are presented. The mean of measurement error of conventional algorithm is about 0.5 mm. That of the novel algorithm introduced in this paper is reduced to about 0.2 mm.
Analysis of electrical signal in Osmanthus fragrans
Lanzhou Wang, Qiao Li, Dongsheng Li, et al.
Platinic electrodes and a biologic enginery testing system are used to determine spontaneous electrical signals in the phloem, cambium and xylem of Osmanthus fragrans for the first time. The signals are denoised by the wavelet soft-threshold de-noising method, which are statistically analyzed in the time domain. De-noised signals retain the true element (the difference less than or equal to 2.6924μV) of original signals well. Results show that the plant spontaneous electrical signals are "μV" in the dimension, and the range of its amplitude in the phloem, cambium and xylem is -80.6878μV~32.3479μV, -41.1557μV~118.0153μV and 284.5316μV~393.1831μV respectively. The direction of the electrical signal in the phloem and cambium varies with the time aperiodically, while the direction of the electrical signal in the xylem is invariable. Its amplitude is significantly higher than the electrical signal in the phloem and cambium.
Heat source recognition in PCB infrared thermal image based on B-spline wavelet transform
Jiuqing Wan, Jinsong Yu, Xingshan Li
Heat sources recognition is very important for Printed Circuit Board (PCB) infrared thermal imaging diagnosis and several recognition techniques have been proposed by former researchers. In this paper the heat sources detection based on wavelet transforms is investigated. Cubic B-spline function is chosen as the smoothing function and its first derivative as the wavelet function. Fast recursive decomposition algorithm for 2-dimensional signal is used to compute wavelet transforms at different scales. Then the temperature gradient distributions on the thermal image of PCB under test can be determined and the bound of the heat sources can be located on the base of the gradient information. Multi-scale edge detection technique offered an opportunity to recognize the heat sources at the same time distinguishing them from the noises by choosing proper detection scale. Experimental results suggest that heat source in PCB thermal image can be recognized successfully using the proposed method.
Research on automatic detection method of nonuniform reflective metal sphere's surface flaws
Under high magnification of the micro-vision systems, the original metal texture appears in the form of bright spots with different shapes and different sizes and mixes with the real flaws such as maculae, pockmarks, and corrosions. The background of the image is complex while the image brightness is non-uniform due to the spherical reflection. It is difficult to extract the flaws accurately by means of traditional segmentation methods. In this paper, a new method for detecting flaws automatically is presented, in which the flaws are located approximately at first by removing the uniform background and the bright spots of metal surface texture, then detected accurately using the method of double-window. The experimental results show that this method is effective to detect various flaws on the surface of metal sphere.
An automatic exposure algorithm based on information entropy
Chi Zhang, Zheng You, Shijie Yu
According to the digital imaging of remote sensing camera and informatics theory, information entropy is presented as the automatic exposure criteria for remote sensing camera and its performance is detailedly analyzed. Aiming at the characteristics of gray-level histogram at different exposure time and the relationships between image brightness and information entropy, improved MCS (Mountain Climbing Servo) is proposed to approach the optimal exposure time in short order. The proposed algorithm has been successfully tested to be effective on a subminiature CMOS remote sensing camera system developed by the authors. Experimental results demonstrate that the proposed criteria can adjust the exposure time automatically according to the image information with high speed, sensitivity and reliability. It is of great value for CMOS camera to improve the quality of space imaging.
Data synchronization of INS and satellite system integration
Wei Wang, Peide Feng
So far, INS/satellite integrated navigation systems have been applied widely in aviation, aircraft automatic approach and landing, land vehicle navigation and tracking, marine applications, and surveying, etc., due to their complementary characteristics. Before the data fusion, the synchronization of data from various systems is the vital challenge and significant guarantee of the integrated navigation system performance. A novel synchronization approach is presented that models the asynchronous time between INS and satellite system data and then estimates it on-line by the Kalman filter in the process of integration. Compared with other synchronization methods, this approach is simple but practical, without any increasing load of the system hardware. And simulation results indicate that the asynchronous time can be estimated real time and the estimated error is smaller than 0.1s. Meanwhile, the accuracy of the integrated navigation system is enhanced remarkably. On the ground of simulation results, it is demonstrated that the synchronization approach proposed in this article is effective.
Data association and passive tracking for multiple targets based on Gaussian sum particle filter
Feng Xue, Zhong Liu, Zhangsong Shi
To improve tracking performance of multi-target tracking, a data association and passive tracking scheme based on the joint probabilistic data association (JPDA) and the Gaussian sum particle filter (GSPF) is proposed. The GSPF is presented to formulate the problem of passive tracking. Compared with sampling importance resampling (SIR) scheme, GSPF can incorporate the most current observations into the particle filter and generate accurate proposal density distribution for the particle filter. Hence, the proposal scheme uses GSPF to track the states of the targets and applies the idea of JPDA directly to the sample sets of multi-target states, and weights of particles are evaluated through the combination of JPDA. The specific implementation steps of JPDA based on GSPF (JPDA/GSPF) are deduced. Trajectory tracking and the root mean square error (RMSE) comparisons are made with JPDA/SIR and JPDA/EKF schemes on simulated data in multi-target passive tracking. Simulation results show that the JPDA/GSPF scheme has better performance than JPDA/SIR and JPDA/EKF scheme in tracking. Furthermore, from the view of particle cost, the JPDA/GSPF introduces higher computation efficiency than JPDA/SIR.
Wavelength selection to increase robustness of the multivariate calibration model in near infrared spectroscopy
Qingbo Li, Xiang Li, Guangjun Zhang, et al.
Genetic algorithm is a non-derived random optimization method based on the regulations of nature selection and evolution. Generally, when genetic algorithm is applied to wavelength selection, only how to improve the prediction accuracy of a regression model is concerned. But the robustness of a regression model, that is, the anti-interference ability towards external measuring conditions variance (such as the ambient temperature, place and so on), is usually ignored. Therefore, when the measuring conditions of the predicted samples change, the regression model would predict the measured samples with high prediction errors. In this paper, genetic algorithm combined with experimental design method was studied to increase the robustness of the multivariate calibration model. In our experiments, the training set was divided into the calibration set and the monitor set to establish the regression model. The spectra of the calibration set samples were measured under the ordinary measuring conditions. The measuring conditions when obtaining the monitor set sample spectra could be arranged according to experimental design method. Kennard/Stone algorithm was used to select monitor set samples from training set. The calibration model could be built with the calibration set samples and optimized with the monitor set samples measured under the designed measuring conditions. And then the validation set samples, which were independent of the training set ones, were employed to evaluate the prediction ability of the regression model. In order to obtain a regression model with high prediction accuracy and robustness, the spectral information caused by the changes of measuring conditions need to be considered and those wavelengths which were easily interfered by external measuring factors need to be rejected when the calibration model was trained. In this paper, the modified wavelength selection method of genetic algorithm was applied to the temperature experiments of the glucose aqueous solution samples. Results revealed that not only fewer wavelengths or principal components were needed to build the calibration model but also the robustness and prediction accuracy of the calibration model were greatly improved. This modified method not only makes the regression model insensitive to external measuring conditions, but also could be applied to the calibration transfer between different instruments of the same type.
Neural network design approach for equiripple FIR digital filters
Xiaohua Wang, Yigang He, Shaosheng Fan, et al.
An equiripple FIR linear-phase digital filters design approach is proposed based on a novel neural network optimization technique. Its goal is to minimize the weight square-error function in the frequency domain. The design solution is presented as a parallel algorithm to approximate the desired frequency response specification, and the weight coefficients are updated according to error function. Thus, the proposed approximation method can avoid the overshoot phenomenon which may happen near the pass-band and stop-band edge of the designed filter, and may make a fast calculation of the filter's coefficients possible. Several optimal design examples are given and the performance comparison between the proposed design approach with some conventional methods, and the results show that the proposed neural network method can easily achieve higher design accuracy.
Lateral inhibition network model optimization by evolutionary strategy for image segmentation
Haihong Hu, Jimin Liang, Heng Zhao, et al.
Image segmentation is a fundamental image processing technology. There are many kinds of image segmentation methods, but most of them are problem oriented. In this paper, image segmentation method based on lateral inhibition network is presented. Lateral inhibition network is a biological vision model. When an image is filtered by a lateral inhibition network, its low frequency components are inhibited while the high frequency components are enhanced. The lateral inhibited image is much easier to be segmented because of its increased inter-class difference and decreased intra-class difference. The parameters of the lateral inhibition network model determine the inhibited image, thus affect the image segmentation result greatly. But there are no assured rules to determine the parameters. We propose an evolutionary strategy (ES) based method to search the optimal weighting parameters of the lateral inhibition network model. The objective function of ES is a multiattribute fitness function that combines multiple criteria of clustering and entropy information. The original image is filtered using the optimal lateral inhibition network and then the inhibited image is segmented by an optimized threshold. Using test images of various characteristics, the proposed method is evaluated by four objective image segmentation evaluation indexes. The experimental results show its validity and universality.
Localization algorithm and error analysis for micro radio-localizer
Xudong Li, Xiaohao Wang, Qiang Li, et al.
After more than ten years' research efforts on the Micro Aerial Vehicle (MAV) since it was proposed in 1990s, the stable flying platform has been matured. The next reasonable goal is to implement more practical applications for MAVs. Equipped with a micro radio-localizer, MAVs have the ability of localizing a target that transmitting radio signals, and further can be a novel promising Anti-Radiation device. A micro radio-localizer prototype and its localization principle and localization algorithm are proposed. The error analysis of the algorithm is also discussed. On the basis of the comparison of the often-used radio localization method, considering the MAVs' inherent limitation on the dimension of the antennas, a signal intensity and guidance information based localization method is proposed. Under the assumption that the electromagnetic wave obeys the free-space spreading model and the signal's power keeps unchanged, the measuring equations under different target motions are established. Localization algorithm is derived. The determination of several factors such as the number of measuring positions, numerical solving method and initial solution is discussed. Error analysis of the localization algorithm is also proposed by utilizing error analysis theory. A radio-localizer prototype is developed and experiment results are shown as well.
An improved empirical mode decomposition based on combining extrapolating extrema with mirror extension
Duanhui Duan, Qiusheng Wang
Empirical mode decomposition is a newly developed method used to analyze nonlinear and nonstationary signals. It has been applied to many engineering domains and has represented some unique advantages. However, in the sifting process of empirical mode decomposition, there is an involved end issue during the course of fitting the upper and lower envelops of the signal by cubic spline function. To deal with the problem, an improved empirical mode decomposition is proposed in this paper. It is based on combining extrapolating extrema with mirror extension. The proposed method can solve the problem that the boundaries of the signal will swing widely when the cubic spline interpolation is used to construct the two envelopes of the signal. The capabilities of the proposed method, the method based on mirror extension and the method based on AR model extension algorithm will be compared in the simulation experiments. The experimental results demonstrate that the proposed method can restrain the end effects effectively.
Echo hiding system for M_ary data and its robustness analysis
Yincheng Qi, Jinsha Yuan, Jingxi Zhang
Echo data hiding is an important approach of audio information hiding in the time domain. But it has serious disadvantages, such as low capacity, relatively low restoration rate and the possibility of malicious tampering, etc. In this paper, based on the simulation analysis of the relation between the detection performance (restoration rate) and the key parameters, we proposed a novel echo M-ary data hiding system using backward and forward echo kernel to improve the weak points of conventional echo data hiding. The subjective quality of the stego audio and the original audio has no evident difference and reach a good hiding effects. The capacity is increased from 50bit/s to 250 bit/s and the restoration rate reaches to 99% for speech in 8000Hz sample frequency, 16 bits quantization, i. e., M=32. And then, we also simulated the robustness performances, such as against adding white noise, resample, filtering, ADPCM compression, etc.
Text independent writer identification based on Gabor filter and SVM classifier
Jun Feng, Yanhai Zhu
Writer identification has become a hot topic in pattern recognition and machine learning research area. This paper studies on the technology of text independent writer identification based on texture analysis. At first in the preprocessing stage the uniform texture images are created from the input document. An approach for improved characters segmentation is presented based on analysis for the character elements and their topological relations. Then the 32-channel Gabor filter is utilized to extract 64 texture features of writing image by calculating the mean values and the standard deviations of filtering output images. Finally, multi-class support vector machines (SVM) classifier is adopted to fulfill the identification task. The experiment result shows that the scheme is effective and promising.
A novel phase estimation method of weak sine signal by using chaotic oscillator
Qiufeng Shang, Yincheng Qi
The chaotic system is sensitive to certain signals and immune to noise at the same time, so the signal-to-noise-ratio (SNR) is improved greatly when the signal embedded in noises passes through the Duffing oscillator system in great period motion state. Based on the SNR improvement property of the Duffing system, a phase estimation method of weak sine signal is proposed. The phase of the output signal is estimated firstly, the relation between the output signal phase and the input signal phase is obtained, and so the phase of the input signal can be got. Digital simulation results prove that the estimation accuracy of the present method is better than both of our previous work and traditional ML estimation method applied to input signal in noise directly. Compared with our previous work, less data is needed.
Study on velocity measurement of stepped-frequency pulse train radar signals
Yunxia Bao, Peikun He, Erke Mao
The Doppler effects caused by radar-target relative motion is one of the central problems in SF Radar, which cause range-velocity coupling and wave distortions. Extensive research is being carried out on various velocity compensation methods, such as varieties rate of range, Min-Entropy, PD processing and correlation methods. However, these methods have different velocity ambiguity and velocity measurement precisions. This paper presents a new method to estimate velocity, which can resolve the problem of ambiguous velocity by PD processing. Firstly, the waveforms of Stepped-frequency pulse trains and PD Processing methods are analyzed. The relation between unambiguous velocity range, precision and signal parameters is discussed. Then, a new algorithm is developed to achieve wide unambiguous velocity and high anti-noise performance, which is similar with the principle of multiple PRFs in Pulsed Radar. Based on parameters in some radar, the algorithm is evaluated. The simulation results confirm the above mentioned achievements.
Kalman-mean shift tracking algorithm based on wavelet moment
Jin Li, Hong Yu, Lulu Zhou, et al.
Robust real-time tracking of non-rigid objects is a challenging task. The difficulty in visual tracking is how to match targets from frame to frame quickly and reliably. Mean shift algorithm (MSA) is a typical nonparametric evaluation algorithm that needs great computation. Some scholars join Kalman filter to perform state prediction in the mean shift algorithm for reducing the computing of template matching. However, traditional Kalman filter sometimes can't track human movement very accurately because of the particularity of human joint. While wavelet moment has the multiresolution properties in addition to the invariant to the translation, scaling and rotation, so it is suitable for differentiating the details of the motion objects. Therefore, Kalman-mean shift tracking algorithm based on wavelet moment (W-K-MSA) is proposed in this paper. In this algorithm, a Kalman filter algorithm, which is used to estimate the motion parameters of targets, is improved based on wavelet moment features in the searching process. And searching window is adaptively changed, as a result, searching scope is reduced greatly, and the processing velocity and veracity is improved during model matching. The experimental results demonstrate that the proposed tracking algorithm is robust and practical.
Study on camera calibration technique of 3D color digitization system
Yuchen Sun, Baozhen Ge
3D (three-dimensional) color digitization of an object is fulfilled by light-stripe method based on laser triangle principle and direct capturing method based on the color photo of the object. With this system, information matching between 3D and color sensor and data registration of different sensors are fulfilled by a sensor calibration process. The process uses the same round filament target to calibrate all of the sensors together. The principle and procedure of the process are presented in detail. Finally, a costume model is 3D color digitized and the obtaining data sets are processed by the method discussed, the results verify the correctness and feasibility of the algorithm.
Adaptive noise reduction for fiber optic gyroscopes in borehole applications
Tingyang Yan, Chunxi Zhang, Shuang Gao, et al.
Fiber Optic Gyroscopes (FOGs) have been investigated and proposed as alternative sensors to magnetometers in borehole surveying applications due to their compactness, ruggedness, low cost and high environmental insensitivity. However, FOGs are subject to high measurement noise from various sources, which deteriorates the performance and quality of FOGs, thus the overall system accuracy is limited. To improve the accuracy of the surveying system, adaptive filtering techniques are utilized to reduce the noise level at the output of the FOG. A Forward Linear Prediction (FLP) filter based on Normalized Least-Mean-Square (NLMS) adaptive algorithm was designed and evaluated using kinematic data. Results show that the FLP filter can suppress the FOG noise to a certain degree and a satisfactory signal-to-noise ratio improvement can be achieved using this method.
Blind fractionally spaced equalizer based on output decorrelation
Yongchuan Wang, Zili Chen
For a SIMO system, when all sub-channels have no non-zero common zeros and channel input signals have zero mean and are temporally uncorrelated, the sufficient and essential condition of equalizing channel is that equalizer output signals are also temporally uncorrelated. Based on this theory, this paper proposes a new equalization algorithm. The proposed algorithm estimates directly equalizer without knowing the channel impulse response. The proposed algorithm is based on equalizer output temporally uncorrelated characteristic and second-order statistics of the received signals. A 16QAM complex SIMO multipath channel system is simulated with the proposed algorithm in this paper. Simulation results show that the proposed algorithm has a good equalization performance.
Stereo matching based on phase congruency corner detector
Hui Ding, Mengyin Fu
Feature point matching is the most common one among all kinds of stereo matching. However, since feature points are unique, the disparity map through feature matching is also sparse. In this paper, proposed a dense disparity estimation method that combines the reliability of feature-based correspondence methods and a reliable feature operator. The new operator uses the principal moments of the phase congruency information to determine corner information. The resulting corner operator is highly localized and has responses that are invariant to image contrast. This results in reliable feature detection under varying illumination conditions with fixed thresholds. Selecting those feature points that allow left-right correspondence based on phase correlation surrounding each point. And use the sparse correspondences at feature points as a constraint to control the computation of dense disparity via regularized block matching that minimizes matching and disparity smoothness errors. Experimental results show that this method can eliminate many kinds of outliers effectively.
Research on MIMU adaptive filter method based on wavelet analysis
Xiaoguang Chen, Jiancheng Fang
Micro Inertia Measurement Unit based on MEMS component, is the core of the Micro Navigation System. Its accuracy has a crucial effect on system precision. Eliminating stochastic noise in MIMU signal is of great significance to increase the system accuracy. Aiming at the different characteristics showed at every scale space after wavelet analysis on MIMU signal, an adaptive filtering method with decomposition level and threshold value self-adaptive adjusting is proposed by this paper. The compactly supported Daubechies4 (db4) orthogonal wavelet is applied to decompose the signal in multi-scale space with self-adaptive level based on white noise sequence check. An improved self-adaptive threshold decision making is adopt for threshold filtering. After removing high frequency detail items generated by stochastic noise, inverse wavelet transform is applied to reconstruct the original signal. The experimental results indicate that the method can eliminate MIMU stochastic noise effectively and achieve satisfactory accuracy. And the algorithm is simple and practical.
Obstacle detection for aircraft based on layered model
An airborne vehicle such as a tactical missile must avoid obstacles like towers, tree branches, mountains and building across the flight path. So the ability to detect and locate obstacles using on-board sensors is an essential step in the autonomous navigation of aircraft low-altitude flight. This paper describes a novel method to detect and locate obstacles using a sequence of images from a passive sensor (TV, FLIR). We model 3D scenes in the field-of-view (FOV) as a collection of approximately planar layers that corresponds to the background and obstacles respectively. So each pixel within a layer can have the same 2D affine motion model which depends on the relative depth of the layer. We formulate the prior assumptions about the layers and scene within a Bayesian decision making framework which is used to automatically determine the assignment of individual pixels to layers. Then, a generalized expectation maximization (EM) method is used to find the MAP solution. Finally, simulation results demonstrate that this method is successful.
An improved normalized cross-correlation algorithm for inspection of printed circuit boards
Fuming Wang
Template matching is one of the best and the most widely used pattern recognition method. Normalized cross-correlation (NCC) is the main matching algorithm for template matching method. For templates with significant gray-level variations, also called features, normalized cross-correlation can be a very simple and effective template matching algorithm, even in cases of noisy data and changing lighting level. In the application of automatic optical inspection of printed circuit board, many electronic components have labels on them and can be used as features for cross-correlation template matching. However, there are quite a few components that have no labels, like some type of capacitors and transistors. They are identified by the color or the shade of gray-level instead. These components pose great difficulties for traditional normalized cross-correlation, which will pick up some random variations as features instead and cause false alarms. People used to deal with this problem by including part of the background into the template to create some artificial features, or by selecting some alternative special algorithms. Both of these methods are not ideal. Because the first method will make the template less universal and subjects to background variations; while the second method will loose many of the nice properties of cross-correlation algorithm. We propose an improved image cross-correlation algorithm, which can recognize both feature based templates and uniform color or gray-level based templates. Compare with the traditional cross-correlation algorithm, this new algorithm can be more accurate and more universal. Experiments have shown that this new algorithm can detect feature-rich, uniformly colored, and uniformly gray templates effectively.
A faster relative 3D position and attitude algorithm based on special four-point feature
Shunliang Pan, Xiaojian Wang, Weiqun Shen, et al.
Computer vision is gaining significant importance as a cheap, passive, and information-rich sensor in research areas such as unmanned vehicle. Using computer vision can estimate relative 3D position and attitude. This paper puts forward a new faster relative 3D position and attitude approach based on special four feature points. This method used prior knowledge of the four feature points of a square and parallel relation, avoided complicated iterative arithmetic in general four feature points' methods, and reduced time of objects position and attitude estimation. The theory and experiments with simulated data showed that the approach is efficient, robust and real-time.
Fusing binary support vector machines (SVM) into multiclass SVM
Zilu Ying, Jingwen Li, Youwei Zhang
Multi-class support vector machine by fusing a class of binary support vector machines is proposed. The classifier fusion approaches include simple combination method such as Maximum, Minimum, Product, Mean, Median and Major Voting. Dempster-Shafer fusion method is also presented as well as KNN and Neural network approaches. The proposed algorithms are applied to the facial expression recognition applications for both the Japanese female facial expression database and the Cohn-Kanade AU-coded facial expression database. The results show that it is effective to combine binary support vector machines (SVM) to a multi-class SVM.
Intelligence approach of traffic sign recognition based on color standardization
Shuangdong Zhu, Tiantian Jiang, Lanlan Liu
Nowadays, for the BP neural network based outdoor traffic sign recognition problems, the recognition rate is generally between 60% and 70%. Based on the results analysis, one may come to a conclusion that the key factors affecting recognition rate are the color distortion caused by the color complexity. This paper present a new solution according to the idea of simplifying the complex problem, using color information and intelligent approach. The first step is to break the complex color information down to 5 kinds of standard color, and then employ BP neural network to classification. In this article BP network is used for Color Standardization, selecting 23 normalization signs as training set and 531 real signs as testing set for BP network. By doing so 100% average recognition rate is achieved. At the same time, it shows the better robustness of the proposed approach for the color distortion of traffic sign in terms of either the structure parameter or the training parameter of network.
Research on network configurations of videogrammetry for the profile of gossamer inflatable antenna
Jun Wang, Naiguang Lu, Wenyi Deng, et al.
In order to enhance the precision of videogrammetry for the profile of large-scale antenna, multi-station network is necessary, which will also affect the reliability, efficiency and stability of the results. In this paper, the impacts of normal and convergent configurations on the precision of space targets are discussed. Constraints, including image scale, depth of field, field of view, and distribution of image points, which affect the network configurations, must be taken into account. Specific network configurations for the large-scale gossamer inflatable antenna are designed and experimental data results verify the conclusions.
A novel description of refractive index in irregular inhomogeneous optical medium
Chunsheng Liu, Xingliang Yin, Tianxu Zhang, et al.
The refractive index distribution in atmosphere or fluid medium is irregular and inhomogeneous, and cannot be described by a usual gradient index formula due to the influence of flowage and change of temperature. In this paper a novel method, namely, self-adaptive grid is used for describing the refractive index in irregular inhomogeneous medium, the refractive index data are stored in RAM as a dynamic octree, the criterion of grid division for refractive index and its gradient are given and the interpolation method is used for calculating the refractive index and its gradient at positions along the ray trace trajectory. A gradient index (GRIN) rod in which the refractive index can be described by a formula is also analysis as an example, the self-adaptive grid is created and the refractive indexes and its gradient at some positions with high accuracy are output. The RMS error is under 7e-5 and can be used for ray tracing.
The design and implementation of constellation simulation and evaluation software
Zhao Jian, Zhao Yan
The effective way of solving integrative design, estimate and optimization of complicated multi-satellite system is establishing integrative simulation software. This paper adopts Object-Oriented and some other interrelated technique, setting purpose on erect flexible simulation platform which means the software should be universal, credible, flexible, compositive and easy. It presented designing project, system structure, realization strategy, and modules of satellite constellation simulation software system. At the same time the paper adopts the method of realizing the visualization of satellite track under Windows platform using Visual C++ and OpenGL, which can make the software intuitionistic and visual. Through the computation of simulation, the coverage performance and implementing cost of GEO-TDRSS and MEO-TDRSS are analyzed and compared. The analysis and simulation results indicate that the MEO-TDRSS can provide better coverage performance with more implementing cost.
Analysis and design of air-cored Halbach array permanent magnet BDCM
Jianhui Zhao, Yanliang Xu
Aimed at the application of satellite attitude control/energy storage flywheel, outer-rotor air-cored permanent magnet brushless direct current machines (BDCM) with Halbach magnet array and the normal one are analyzed comparatively. A prototyped BDCM with Halbach array is designed and fabricated to verify the analysis and satisfy the performance demand of flywheel system.
The navigation receiver simulation and estimate software system design
Xiaoxiao Yi, Yan Zhao
Developing the satellite positioning and navigation system independently is a huge project. Establishing the simulation and estimate software system for navigation receivers can supply reference data for developing and improving real receivers. This paper analyzed the general structure of the receiver, presented a more feasible design method for the receiver simulation and estimate software system, introduced some estimate items and the data or algorithms which the items needed, and proposed a solution to C/A code rapid acquisition with inertial navigation system (INS) assisting. This software system consists of a signal simulator, a navigation receiver simulator and a receiver estimate software and is based on MATLAB/SIMULINK. It helps to configure a precise receiver simulation and estimate system.
Wireless sensor networks
Chris Guy
This paper provides an introduction to Wireless Sensor Networks (WSN), their applications in the field of control engineering and elsewhere and gives pointers to future research needs. WSN are collections of stand-alone devices which, typically, have one or more sensors (e.g. temperature, light level), some limited processing capability and a wireless interface allowing communication with a base station. As they are usually battery powered, the biggest challenge is to achieve the necessary monitoring whilst using the least amount of power.
Changing face of surface metrology
In common with most disciplines surface metrology is having to evolve in order to meet the new requirements demanded by miniaturization and the increased use of semi conductor planar technology. Changes are taking place in theory as well as in the other constituents of an engineering design such as material properties and new manufacturing processes. In this paper a number of issues will be discussed. They will be by no means a comprehensive list but sufficient will be investigated to give an idea of the nature and scope on the problem. Amongst the topics covered will be nomenclature, some mechanical properties, force balance etc. There will be a look back at the way in which surface metrology evolved to see if lessons can be learned.
Survey on piezoelectric actuators: applications, modeling, power supply, and control
Horst Grotstollen
Piezoelectric actuator systems feature strong interactions between the mechanical system to be operated, the actuator and its power supply. Therefore they are typical mechatronic systems and good design results cannot be achieved but by an integrated design of all components. Furthermore the electromechanical system is operated in a resonant mode demanding for special a modeling technique and adopted control schemes. The paper gives a survey on this interesting field of electrical drives and some interesting applications.
High-accuracy measuring method of absorbed dose using radiochromic film and a microdensitometer for high-energy x rays
Hideki Aoyama, Yoshiharu Azuma, Sachiko Goto, et al.
Radiochromic film has been applied to mapping of dose distributions in radiation therapy. However, this particular RCF product suffers from intrinsic nonuniform response. In this study, we have carefully measured the nonuniformity of unirradiated RCF, and the response of irradiated RCF in pixel-to-pixel as function of various absorbed doses, in order to create a method of predicting the error of irradiated, unirradiated RCF.
Signal processing methods based on fuzzy probability and psychological evaluation for sound environment
Akira Ikuta
The actual sound environment system exhibits various types of linear and non-linear characteristics, and it often contains an unknown structure. Furthermore, the observations in the sound environment often contain fuzziness due to several causes. In this paper, static and dynamic signal processing methods for estimating and predicting the specific signal of sound environment systems with unknown structure and fuzzy observation are proposed by introducing a fuzzy probability theory. The effectiveness of the proposed theoretical methods is confirmed by applying them to the actual problem of psychological evaluation for the sound environment.
Analysis of BGA defects by tomographic images
T. Sumimoto, T. Maruyama, Y. Azuma, et al.
To improve the cost of performance in manufacturing IC packages, it is required to inspect BGA defects in the online process. The problems of image analysis for the detection of defects are the detection accuracy and image processing time according to a line speed of production. Using the X-ray penetration equipment, we have captured images of an IC package to search an abnormal BGA. To get design data for the development of the inspection system, which can be used easily in the surface mount process, we tried to capture the tomographic images utilizing the latest imaging techniques.
Fast RLS Fourier analyzers for sinusoidal signals in noise and application
Yegui Xiao, Liying Ma, Akira Ikuta
The conventional recursive least square (RLS) Fourier analyzer enjoys excellent performance, but is computationally very intensive. In this paper, we first propose four fast RLS (FRLS) algorithms by utilizing the inherent characteristics of the estimation problem. The four new FRLS algorithms show almost the same performance and indicate estimation capabilities that are very similar to those of the original RLS, but require considerably less computations. Performance of the proposed FRLS algorithms is then analyzed in detail. Difference equations governing their dynamics as well as closed-form expressions for their steady-state mean squared errors (MSE) are derived and compared with those of the LMS Fourier analyzer. Extensive simulations as well as application to real noise signals are provided to demonstrate the validity of the analytical findings and the effectiveness of the proposed algorithms, respectively.
The application of wavelet transform for oceanic feature detection in SAR and optical image
Yessy Arvelyna, Masaki Oshima, Tetsuhiro Sumimoto
Wavelet transform has been applied for multi resolution analysis of oceanic feature in ERS1/2 SAR and ASTER image data over the Tsushima Strait. Various wavelet transforms, e.g. Haar, Daubechies, Symlet, Coif, Biorthogonal, and Meyer wavelet, have been tested comparably with different level of synthesized image on horizontal, diagonal, and vertical detail, and approximation to study the internal wave characteristic in image. The results show that higher scale processing of image and higher number of vanishing moments of wavelet function such as Coiflet wavelet, coif5, Daubechies wavelet, db5, Symlet wavelet, sym8, and Discrete Meyer wavelet, are proposed for smoother wave crest. The best result of detection is performed by Discrete Meyer wavelet transform, which adapts FIR filter, orthogonal and biorthogonal basis. Thus, it liable for smoothness of feature, space save coding and avoid dephasing in image.
Hierarchical type intersubjective relationship based on attachment of tecnoAO between sound (utility) and magnetism (risk) for wavy environment around VDT
Yoshifumi Fujita, Mitsuo Ohta
In this paper, first, a methodological principle trial for the quantitative evaluation of the correlative and/or cumulative effect on indoor high-technology pollution has been proposed under an absolutely inseparable relationship at the same time and in the same ring. Then, the effectiveness of the proposed method is partly confirmed through some principle experiment between sound(served for utility) and leaked magnetic field(served for risk) before and after the attachment of tecnoAO.
Estimation of breast density on digital mammograms
Sachiko Goto, Yoshiharu Azuma, Hideki Aoyama, et al.
We built an estimation system of individual breast density from digital mammograms by using breast tissue equivalent phantoms that are able to change the mixture ratio of adipose and glandular tissue and the thickness. The method was compared with a visual assessment of breast density by the radiologists as a gold standard. The clinical image data set average of the estimated glandular rate was 35.0%, while varying from 12.0% to 67.0%. This system can apply in clinical practice such as the visual estimation of breast density.
Development of high-time-resolution measurement system of frequency characteristics in bioelectrical impedance for biodynamic analysis
Takao Nakamura, Toshimasa Kusuhara, Yoshitake Yamamoto
We have proposed biodynamic analysis using bioelectrical impedance at 50 kHz, which is measured with synchronous rectification method. In order to analyze impedance parameters in biodynamics, the measurement of frequency characteristics in bioelectrical impedance with a high time resolution are required. Therefore we have developed a high time resolution measurement system for bioelectrical impedance with 10 frequency points and time resolution of 1 ms. A voltage EA, which consisted of fundamental wave and 9 kinds of harmonic wave from 1 kHz to 1MHz, were converted to current. The current flowed through human body and a potential voltage, EV was detected in the measured part. After A/D conversion of EV and EA in the sampling frequency 2 MHz, data number 2048 points, the impedance were calculated using Fast Fourier Transform. The measured time 1.024 ms was the period of the fundamental wave and time resolution of this system. The specification is enough accuracy for measurement of bioelectrical impedance for biodynamic analysis.
Optical electronic measuring systems and laser technologies for scientific and industrial applications
Yuri V. Chugui, Vladimir S. Bazin, Leonid V. Finogenov, et al.
The novel results of the R and D activity of TDI SIE SB RAS in the field of the optical measuring technologies, as well as laser technologies for solving actual problems are presented. The metrological characterization of a perspective Fresnel method for high precision measuring the dimensions of objects is investigated. An optoelectronic noncontact method using diffractive optical element (DOE) for the 3D inspection of article holes is presented. A structured light method and system testing results for noncontact inspection of wire wear and its defects for train electro-supply network are discussed. For permanent noncontact bearing position inspection of oil-drilling platforms on Sakhalin coast (Russia) under extreme temperatures (± 40°C) we have developed optical-electronic method and system SAKHALIN. Multifunctional laser technological system LSP-2000 equipped by two Nd-YAG lasers was developed for cutting, welding and surface micro profiling with ablation process (working range of 3 x 3 x 0.6 m3, positioning error less than 10 μm). Safety of Russian nuclear reactors takes 100 % noncontact 3D dimensional inspection of all parts of fuel assemblies, including grid spacers. Results of development and testing the specialized high productive laser measuring machine, based on structured illumination, for 3D inspection of grid spacers with micron resolution are presented. For safety increasing of Russian railways TDI SIE has developed and produced automatic laser diagnostic system COMPLEX for inspection of geometric parameters of wagon wheel pairs for running train (speed up to 60 km/hr.), which is used successfully on Russian railways.
Measurement Theory and Technology
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Coal mud contact surface indirect survey technology
Guijun Gao, Ziming Kou
The concentration pond is used in the most coal washing plants for treating coal washing water. We must know the coal mud contact surface in the use of concentration pond so that we can prevent presses the rake accident appears and that simultaneously know how to operate next step for worker. Formerly we survey coal mud contact surface depended on the man-power. People with one thin wooden stick insertion concentration pond in and after mentioned remains with the naked eye observation to the thin wooden stick coal mud trace and to estimate the deep of coal mud contact surface. Like this there are some questions of existence lag and accurate bad. So I propose one kind of coal mud contact surface indirect survey technology. First, I survey the different depth coal washing water density using density meter and I get a coal washing water density gradient. Then, according to the gradient I can establishment the coal washing water density mathematical model. Because coal washing water density is changed with different seasons, so I get different coal washing water density mathematical model. Finally, I fix the density meter to one depth place to get the water density and then put the density in the mathematical model to calculate the contact surface depth value. All the mathematical computation depends upon LABWIEV software at the same time can realized coal mud contact surface depth value digital display.
Realization of simultaneous strain and temperature measurement using FBG
Dandan Zhu, Zhiquan Li, Yan Li, et al.
Fiber grating works as a novel kind of smart sensing element. It adopts wavelength encoding. It is prone to multi-points multiplexing and it is compatible with normal fiber system completely. It has been got extensive and deeply research in fiber sensing field because such advantages. In order to realize simultaneous strain and temperature measurement, solving temperature and strain's cross sensitivity is the key problem in fiber grating sensors researching. Simultaneous strain and temperature measurement using fiber Bragg grating(FBG) is presented in this paper. Different cladding diameter fiber solve temperature and strain's cross sensitivity problem. Demodulation system adopts arrayed-waveguide grating (AWG). It has merits of high wavelength resolution, integrated, small series-mode interference and low insertion loss. Light source adopted clock pulse broadband source. The system integrates time division multiplexing and wavelength division multiplexing to solve the multiplexing addressing problem of FBG sensing network. It proved feasibly according theoretical analyzing. Measuring strain range from 0 to 2500 με. Measuring temperature range from 25 to 120°. Error of strain is ± 17 με and error of temperature is ±1°C.
Optimizing design of tool interpolating algorithm in NC system
Chuangwen Xu, Hualing Cheng, Baodong Li
The line and arc is approached by broken line in point by point comparison interpolating algorithm. If the pulse (the distance of one step) is short enough, the precision is high enough. If the pulse is 0.01 and the feed speed is no more than 3000mm/min, the precision of point by point comparison interpolating algorithm is well enough to meet the needs. But if the pulse is 0.005mm to 0.001mm and the feed speed is more than 3000mm/min, the number of interpolating point is more and more. The CPU is busy with the value of moving coordinate calculate and the pulse of feed set and occupy more resource, so the problem of lag, out of step and creep by low speed in Multi-axis. Then speed of response and interpolating precision about the system is effect. In this paper, In view of the principle of point by point comparison method, advance the foundation deciding whether the middle point interpolation is the control forth step error of NC system, establish math model of inserting and compensation method, change and improve the function that judge error by interpolating method. According to the result of the example, the middle interpolation method make interpolation precision raise from 1 pulse equivalent to 0.5 pulse equivalent, and interpolation points are greatly reduced, respond velocity quicken and interpolation precision heighten.
Implementation of medical monitor system based on networks
Hui Yu, Yuzhen Cao, Lixin Zhang, et al.
In this paper, the development trend of medical monitor system is analyzed and portable trend and network function become more and more popular among all kinds of medical monitor devices. The architecture of medical network monitor system solution is provided and design and implementation details of medical monitor terminal, monitor center software, distributed medical database and two kind of medical information terminal are especially discussed. Rabbit3000 system is used in medical monitor terminal to implement security administration of data transfer on network, human-machine interface, power management and DSP interface while DSP chip TMS5402 is used in signal analysis and data compression. Distributed medical database is designed for hospital center according to DICOM information model and HL7 standard. Pocket medical information terminal based on ARM9 embedded platform is also developed to interactive with center database on networks. Two kernels based on WINCE are customized and corresponding terminal software are developed for nurse's routine care and doctor's auxiliary diagnosis. Now invention patent of the monitor terminal is approved and manufacture and clinic test plans are scheduled. Applications for invention patent are also arranged for two medical information terminals.
Profile measuring and topography modeling of aluminum alloy sheet surface
Wei Zhang, Zhigang Li
With the development of lightweight vehicles, aluminum alloy sheet plays a more and more important role in auto panel production because of its high strength and low mass. However, aluminum alloy sheet is more difficult to forming than steel and its contact and friction behavior with the die surface in warm forming is more complicated. In order to study the laws of the contact and friction behavior, the topography data of aluminum alloy sheet surface should be obtained first so that the topography model can be set up. The authors introduce the principle and the performance of AF-LI Contact and Non-contact Synthesis Measuring Profilometer, get the topography data of aluminum alloy sheet surface by using contact measuring method. Then a statistical topography model of aluminum alloy sheet surface is set up based on the data.
Key techniques for vision measurement of 3D object surface
Huachao Yang, Shubi Zhang, Guangli Guo, et al.
Digital close-range photogrammetry system and machine vision are widely used in production control, quality inspection. The main aim is to provide accurate 3D objects or reconstruction of an object surface and give an expression to an object shape. First, the key techniques of camera calibration and target image positioning for 3D object surface vision measurement were briefly reviewed and analyzed in this paper. Then, an innovative and effect method for precise space coordinates measurements was proposed. Test research proved that the thought and methods we proposed about image segmentation, detection and positioning of circular marks were effective and valid. A propriety weight value for adding parameters, control points and orientation elements in bundle adjustment with self-calibration are advantageous to gaining high accuracy of space coordinates. The RMS error of check points is less than ±1 mm, which can meet the requirement in industrial measurement with high accuracy.
The design of heart sounds and electrocardiogram monitor system based Atmega 128L
Miao Cao, Zhiyong An, Ying Zhang
This paper introduces a realtime system which can acquire,process,store and display heart sounds and electrocardiogram(ECG) of the human body at the same time.It is composed of superior microprocessor--Atmega128L,large capacity Flash and the new type LCD.All hardwares adopt low power design and surface mounting package. The specialities of the system are low power, compact, and high intelligence. In consideration of transplant and solidity of the system, at the same time, it ensures that some complicated arithmetic can be realized.The system software applies mold construction and programs in C language. A model for automatic arithmetic is established for the feature extraction of ECG, realtime cardiotach ambulatory analysis is realized. The system is capable of recording ECG and heart sounds information in succession for 48 hours and it stores the no compression data synchronously. More than ten types of familiar heart diseases can be diagnosed in time by it automatically. The testing data achieved from this system is dependable, the diagnosing result is accurate and the waveform is no distortion. It solved a problem within the same kind of products effectively, that is, the dynamic ECG and heart sounds signal are acquired separately. The system do not affect the daily living and working of human being when it is used, so it is suited for clinical and family monitoring.
A novel method of EMC test at the system level of UAV
Bo Li, Daqing Huang, Riurui Nie
The purport of EMC (Electromagnetic Compatibility) is that the electric and electronic equipments or subsystems can work normally according to the advanced project requirements in the intentional electromagnetic environments. Nowadays, design for EMC has played a more and more important role in system plan. The UAV (Unmanned Aerial Vehicle) devisers have cognizance of this point too. But it is regretful that the importance of EMC test is often ignored in the design of UAV, especially the test at the system level, to the detriment of total UAV performance. Complete EMC test at the systems level is often a difficult goal, since system is often too large to adequately or efficiently test, or complete UAV is not for test available until initial customer installation, where test could be impractical. And it is more serious that there are no ready-made UAV standards of EMC test at the system level to be complied with. Following a review of definition and background of systems EMC of UAV, along with the relationships between the EMC test at the subsystem level and the test at the system level, the author describes an novel and effective method of EMC test at the system level, continues with the details of the testing items and their academic bases and some noticeable proceedings of the test. Finally, some conclusions of the EMC test at the system level of UAV are given.
Research and analysis on new test lenses for calibration of focimeters used for measuring contact lenses
Jiyan Zhang, Liru Wang, Zhenya Ma
A focimeter is one of the basic ophthalmic instruments used in every optometric practice, and verification of the accuracy and calibration of the instrument are of the utmost importance. For many years the International Standardization for Organization requires that calibrations for all kinds of focimeters shall be accomplished by using test lenses described in ISO 9342:1996. These test lenses must be of high quality and of nominal back vertex power that is known with high accuracy. With the development of science and technology, ISO 9342 was revised in 2005. A new part ISO 9342-2 had been drafted for test lenses used to calibrate focimeters with contact lens measurement, and the original ISO 9342 was turned into the current ISO 9342-1, which could only be used to calibrate fociemters with spectacle lens measurement. As one of the standard drafters, the background for the newly published ISO 9342-2 is introduced in this study, and comparison between test lenses of ISO 9342-1 and ISO 9342-2 is made. Further, the influence of tolerance and uncertainty in design and production of standard test lenses of ISO 9342-2 is analyzed. The paraxial approximation is used to relate the lens parameters with back vertex power and to calculate the uncertainty budget. Moreover, one set of test lenses conforming to ISO 9342-2 is manufactured and experiments are done with it. Results show that test lenses described in ISO 9342-2 can correct the measurement errors of focimeters used for measuring contact lenses well, especially for spherical aberration, and the correction is more effective for spherical contact lenses with high back vertex power.
Cylindricity compound errors reversal separation method
Zi Xue, Xiaoyou Ye
Spatial rotation error of the spindle, straight movement error of the straight guide, parallelism error between the guide and the spindle are principle error sources for the cylindricity measuring instrument. It is a difficult problem all the time for high precision cylindricity measurement to separate synchronously and effectively the three errors from the cylindricity result. In order to solve the problem, a novel method for high precision cylindricity error separation is developed. The method is developed based on the characteristics which the directions of the movement errors on the two radial ends of the cylindrical artifact are always reverse each other, and the cylindrical surface form can be separated by combination arrangement of the sensors and the error separation table and mutual addition among the measured signals on the different positions. The method can be used to remove totally the spatial rotation error of the spindle, straight movement error of the straight guide, parallelism error between the guide and the spindle in principal. The simulation results show that the method can effectively improve the measurement precision of the cylindrical artifact and the high precision cylindrical profile.
A sliding DFT algorithm for electric power measurement
Xin Tang, Xiangjun Zeng, Chunming Tu
With the advent of electronic meters, a variety of methods are now practical for measuring electrical quantities such as real power, reactive power and power factor etc. To reduce computation, a sliding discrete Fourier transform (DFT) algorithm for electric power measuring is presented. The sliding DFT calculates the components of utility voltages and currents described by factor Ai and Bi, which can be used to calculate power components. In the transform, the data of voltage and current are sampled synchronously, and each new DFT is efficiently computed directly from the results of the previous DFT. As a result, the overall computation time is reduced significantly. Theoretic analysis and simulation demonstrate the feasibility of the proposed method.
Sinusoidal phase modulating interferometer base on integration method
Zhongbao Xu, Nan Zhang
We describe a sinusoidal phase modulating interferometer in which a CCD image sensor measure phase values, the method uses four frames obtained by integration of the time-varying intensity in an interference pattern during the four quarters of the modulation period. The optimum amplitude and phase of the sinusoidal phase modulation were determined by considering the measurement error that is resulted in the additive noise; the effect caused by the deviation from the optimum phase modulation is analyzed. Theoretical analyses and experimental verifications have shown that the distance-measurement accuracy is 2.7 nm with these techniques.
A novel calibration of the CAT system for joint internal thread
Qiang Zhou, Fengxin Yu, Shouqian Yu
The testing of the internal taper thread in joint is the key measurement on spot. The automatic CAT system has been developed for testing key parameters of internal thread on the machine tool. The six key parameters of the 2 7/8EU internal taper thread could be given by the CAT system. A simple and effective method has been developed for the calibration of the sensors in the CAT system. It is called tracing standard part method, which has the simple procedure with high precision. The tooth depth of the joint internal taper thread given by the manual gauge has been chosen for the coefficient calibration of the range sensor in the CAT system. The calibration method has been verified on the spot with manual gauge. It has been shown that this novel calibration method could meet the demanding of the user's precision.
The development of radon chamber based on dynamic replenishment model
Shumin Zhou, Yamin Sun, Ling Lu, et al.
As a standard instrument to calibrate the radon monitors, radon chamber is in urgent need with the deepening study on Radon and its progeny. According to the requirement of calibrating the radon monitors and radon detectors, the multifunctional and automatic controlled radon chamber is designed and constructed. By the reason of radon decay, the radon concentration in the chamber is continuously changing. The radon concentration must keep stability and homogeneity in order to calibrate the radon monitors and bio-culture. The supply and control of radon in the chamber is a critical problem in the design of Radon chamber. The paper introduced the mathematic model of dynamic radon replenishment according to the law of radon decay, three time parameters to replenish radon is discussed. The related automatic monitor and control system is developed by this mathematic model, the expected radon concentration can keep stability and homogeneity controlled by the system. The structure of radon chamber and the design flow system is presented in detail. The main performance parameter of the radon chamber such as airproof, stability and radon concentration certification is discussed. The research result can be used to calibrate the radon monitors, biological test on radiation environment and radiation medicine test.
The design of online intellectual checkout system for car's hole and axle part based on ARM
Sheng Zhao, Shan Chen
The merits of online intellectual checkout system for car's hole and axle part based on the ARM chip S3C4510B is introduced in this paper, and its configurations of the hardware and software system are designed. The hardware mainly includes the structure based on S3C4510B, the analog input circuit and the Ethernet interface circuit. The algorithm of the online intellectual checkout system and the embedded operation system of porting uclinux for the online intellectual checkout system in details are given. The system realizes the lucid transmission between the online intellectual checkout system and the home site by Ethernet. It has the characteristics of high reliability, strong real-time and high speed of transmission.
Study of the effect of CCD camera noise on microscopic autofocus criteria functions
Chao Yu, Boxiong Wang, Hanqing Zheng, et al.
Passive focusing techniques, which are based on the analysis of image sequences to decide the optimal imaging plane position and moving direction for focusing, are widely used for stroboscopic autofocus system nowadays. When a CCD camera is used to get images, noise of camera may result in errors in the images, and cause the autofocus process inefficient. Thus it is necessary to study microscopic images affected by camera noises to choose the suitable autofocus method. Camera noises usually include photon noise, dark current noise, photo response non-uniformity noise and read-out noise. In our CCD camera-microscopic experiment system, a micro accelerometer is used as the measured object. To analyze the effect of camera noises, we add some camera noises to the images, and run the autofocus process. One of the key techniques for microscopic autofous is its criteria function. Criteria function curves of images are analyzed and compared, including image gradient energy function, variance function, Tennengrad function and Laplace function. Spatial Poisson distribution noises and spatial Gaussian distribution noises are added to images to simulate the camera noises with different expectations and variances. Experiment results show that the performances of these criteria functions are different with different noises added.
Research on reliability test circuit of pneumatic pressure regulator
Jungong Ma, Haitao Wang, Naotake Oneyama, et al.
In order to evaluate ISO/CD19973-4, some items had been tested, such as step response, valve opening, feasible opening frequency, air consumption, piping influence, cycle response and so on. The results show that Valve opening varies sensitively to the size of piping, solenoid valve and test chamber. The valve of regulator opens to some extent, closes immediately, and never reaches the full opening. If these circuit specifications are defined concretely and observed strictly, it is not impossible to obtain a certain required opening ratio and air consumption is very large. On the side, the compared tests based on the Japanese JIS test circuit having been carried out, the results show that, regardless of test circuit specifications, the valve of regulator always repeats full closing and full opening. The relief valve of the regulator operates too. At the same operating frequency, air consumption is one digit less than the one in ISO/CD 19973-4 circuit. In the end, improved JIS circuit was put forward as a reliability circuit of pneumatic pressure regulator.
Concentration-distribution-architecture-based engine stress test system
Jie Xie, Bo Yang, Qiang He
A test system is designed based on concentration-distribution architecture for vehicle engine case and cylinder cap measurement, and it is component with portable personal computer, mother system and multiple subsystems. The subsystem is fixed on the engine partition, and the computer receives data sampled by subsystem via mother-system. Analog circuit charged in stress feeling is subsystem, digital circuit that sampling the analog circuit output is mother-system, and the two parts are designed individually. The testing system is good at select channels, self-adjusting, data sample frequency adjusting, gain adjusting, result output, data processing and graphics printing, with great advantages of high automatic level, easy using and great extensibility. Some other systems can easy be achieved by changing different sensors for different measurement purpose such as temperature, pressure and force etc. This method is used in temperature and pressure measurement of a type of engine and it performances well.
Denoising of electrical derivative data of semiconductor lasers based on nonlinear diffusion equation
Fengli Gao, Shuxu Guo, Bibo Lu, et al.
The method of screening semiconductor lasers by using electrical derivative technique is described in detail. The nonlinear diffusion equation is applied to denoising of electrical derivative data according to its denoising theory in signal processing. The denoising experiments of electrical derivative data for several dozens semiconductor lasers indicate that the denoising method can effectively reduce the noise in electrical derivative data and the errors of the measured parameters. The farther experiments indicate that the accurate estimate ratio of the devices can be effectively increased by using the measured parameters which have been denoised, to estimate the quality and reliability of semiconductor lasers.
Three-sensor tracing principle for crankshaft roundness error measurement during noncircular grinding process
Yingzhong Tian, Ming Li, Wei Li, et al.
Researches are made to find out the active tracing measurement strategy of crankshaft roundness error during noncircular grinding process. This paper makes a detailed study on the tracing motion equations of the measurement system. Aiming at the request of three sensors' linear dependence in frequency-domain analysis, this paper also describes the constraint condition of uniform sampling. For improve the in-situ measurement precision, the three-sensor tracing principle of roundness error separation (TTPRES) is proposed under motion stage. Furthermore, the method for avoiding harmonic suppression by adjusting the installation angles of three sensors is discussed. Finally, the data processed by error separating are calculated using Least Square Method (LSM), and contrasted the compute result with the measurement result of Roundness Measuring Instrument. The experiment proves the validity of in-situ tracing measurement strategy of crankshaft roundness error during noncircular grinding process.
Multiscale features analysis of 3D surface topography based on mathematical morphology
Xiaojun Liu, Yi Huang, Kun Liu, et al.
In order to establish the relationship between the multi-scale features of 3D surface topography and its functional performances, a novel technique is presented for the multi-scale features characterization of 3D surface topography by greylevel morphological transform. By multi-scale morphological operations with structuring elements of different sizes, the structure features of the surface at different scales are extracted. Application of this technique to plateau honing surface has shown that multi-scale analysis based on the graylevel morphological transform is an effective method for providing texture components of different scales of 3D surface topography generated by multi-process manufacturing method. A new way to accurately determine the dividing point indicating the transition from fine plateau to deep groves is given. Based on the transition point, the surface bearing index and valley oil retention index are revised. The two revised parameters provide a more practical and exact means for characterizing the load carrying capacity and oil retention property of plateau honing surface.
Design and realization of online monitoring system for blade condition of mixture machine based on Bluetooth
Zheng Qian, Shufen Teng
It is very important for mixture machine to make real-time pressure monitor of blade condition in order to ensure the quality of product and the safety of producing course. However, it is difficult to measure this pressure by using wire-method. Thus it is urgently required to develop the wireless monitoring system. In this paper, an on-line monitoring system by using the Bluetooth wireless transmission technology is designed and realized. According to the structure of mixture machine, several pressure sensors are fixed on the two blades which are the solid blade and the hollow blade respectively. The multi-channel switch, instrument amplifier and A/D converter are used to process the output signals of all pressure sensors. These signals could be acquired and transmitted by the Bluetooth acquisition module. Moreover, the Bluetooth module on the wall of mixture machine is utilized to receive these signals and to transmit them to the outside main controller. The real-time data acquisition of the blade condition is implemented by using the communication mode of one master and two slaves. This system has been tested successfully in the lad, the rationality and the feasibility is verified simultaneously.
Simulation of CIS speech signal processing strategy based on electrical stimulating model of cochlear implant
Zheng Qian, Dan Yu
During the operating course of Cochlear implant, the speech signal processing strategy converts original speech signal into dim current signal. And then this signal will be transmitted into the embedded electrode to stimulate the remnant auditory nerve to restore the audition of patient. It could be shown that the speech processing strategy is the key part to realize the performance of cochlear implant, but its evaluation method for validity is always lacking. In this paper, the electrical stimulating model of cochlear implant is established at first, and then the acoustic simulation of Continuous Interleaved Sampling (CIS) strategy could be finished on this model. The synthesizing signal simulates the speech signal which could be heard by the deaf with cochlear implant. Therefore, the identification ability of CIS strategy could be estimated by delivering this synthesizing signal to normal audition people. Further more, some detailed analyses for every step of this acoustic simulation could be considered in order to improve the performance and parameters selection of CIS strategy. This work will be helpful for the deaf to enhance their perception and understanding during the speech identification course.
Design of test system of the control and logic transform device of the flight control system based on FPGA
Liru Wang, Qingrong Zhang
The control and logic transform device is the centrum of the flight control system. This paper mainly introduces the design of the circuit of the test system which is used to test the control and logic transform device. Based on the hardware and software, the test system can test and fault diagnose the device according to a series of given test vectors. Besides, the test system can collect and test some flight analog signals, such as the power signal, the pitching signal, the leaning signal, the Mach number, the height number and etc. The test system is made up of the testing object, the logic control and interface circuit and the computer. The functions of collecting the measurands, controlling, arbitrating and converting the logic signals of the circuit are achieved by the test interface circuit, which is mainly integrated in EPF10K20RC240, Field Programmable Gate Array, produced by the Altera semiconductor corporation. This makes the circuit predigested, the integrated level of the system heightened, the size reduced, the stability and the secrecy of the system ensured. This paper introduces the design of the circuit, the working principles of the logic control and interface circuit, stressing how to use the FPGA to realize integrating the test interface circuit mostly. Some details which should be paid much attention to about the emulation and the design are also discussed in this paper. Finally, the paper introduces how to use power MOSFET as the electron switches to switch the multiplex measurands to realize low power consumption.
Research on the capability testing and analyzing system of the embedded turbocharger
Mingfu Zhao, Liang Li, Yu Dong, et al.
At present, the domestic turbocharger's ex-factory testing used to adopting pointer indicators which read testing data by manpower. In order to improve the turbocharger capability test and the efficiency of the automatic intelligent degree, the paper designs a new turbocharger capability testing system which adopts the embedded processor ARM7 as its core. The system contains test platform, embedded acquisition system and PC capability analyzing software, realizes many functions such as data acquisition, parameter supervising, capability analyses and long distance transmission etc. Applied by the ChongQing JiangJin Runoff Turbocharger Factory, it is turn out to be that the system has perfect function, credible run, precise testing data, friendly software interface and simple manipulation to improve the testing efficiency and have a bright future.
Research of roll shape measurement methods in CNC roll grinder
Liwen Yan, Tao Yu, Meiting Wan
In view of existing measurement methods for Roll Shape, a kind of measurement based on roll shape is put forward. Based on analysis of roll shape curves, a new roll shape compensation and error separation method is put forward. Measurement equipment for roll shape is designed, which can do errors analysis and compensation. The simulation result shows that the roll shape measurement plan can improve the measurement precision.
Calibration coefficient model of coaxial calibration kit for network analyzer
Xinmeng Liu, Xiyuan Peng, Hui Huang
This paper derives Calibration Coefficients Model of coaxial calibration kit for network analyzer firstly. Then an example of one port reflection measurement is used to show how to use Calibration Coefficients Model in the calibration process. After a comparison of network analyzer measurement errors from different calibration coefficients sets, a conclusion is given at last.
Parameter estimation and its application using nonstatistical theory
Xintao Xia, Xiaoyang Chen, Zhongyu Wang, et al.
In many social science and natural science research, researchers are often faced with the problems such as: the system have no enough system distinctive features, the probability distribution unknown and the number of data very small. It is hard to use statistical theory in these researches. A novel method called non-statistical method is proposed in this paper to obtain more characteristics and further information in the system. The method permits the probability distribution unknown and the number of data very small, because of some deficiency of classical statistics in system and information science. In virtue of the special strategy of data processing, more characteristics and further information in the system could be obtained using this method. Some basic concepts, characteristics and elements of non-statistical method including point estimation, interval estimation, optimum level, practicable interval and systemic characteristic mapping etc, are also recommended. The validity of this method is examined by some measurement cases and practical engineering examples.
Norm theory of error separation and its application to harmonic distribution parameters of rolling bearing surfaces
Xintao Xia, Xiaoyang Chen, Zhongyu Wang, et al.
Error separation technologies are widely used in practical engineering. Many methods such as least squares techniques, Kalman filtering, three-probe method, so on and so forth are adopted in error separation technologies. However, It has been proved that these methods above can be disturbed by the outlier of measured data and is likely to induce a biased estimation. Therefore a new method of error separation in data analysis is introduced in this paper by developing the minimum norm solution to estimation of nonlinear parameter vector. Three norms, i.e. 1-norm, 2-norm and ∞-norm, are proposed to establish the equation of error separation. As an application of this method, estimation of harmonic distribution parameters of rolling bearing raceway surfaces is studied in this paper. Experimental investigation by this method shows that the bug of least-squares method can be avoided by efficiently deadening the disturbing errors of the outlier of measuring data and the nature character of measured data can then be reflected truly, that unbiased estimate of distribution characteristics can be achieved and standard deviation through this method can then be less than that through linear least squares techniques. The feasibility of the proposed method is validated by experiments on harmonic distribution parameters of rolling bearing raceway surfaces.
Measurement and positioning of moving array shape by IR-UWB
Hongkun He, Haoshan Shi
Based on impulse radio ultra wide band (IR-UWB) technology, the measuring and positioning of moving array shape are discussed. Because there are no conditions of fixed receivers and clock synchronization in real outdoor or field surroundings, only choice is unusual asynchronous measurement method, therefore, the scheme of measuring and processing must be changed, though the current TOA (Time Of Arrival) method is used. The array shape and positions of moving objects are both required in the most situations. The direct approach is to increase the number of measuring point, and the positioning problem would be resolved by triangular surveying method. The solution is generic at first sight, but its sensitivity to time-of-arrival accuracy imposes the choice of impulse radio ultra wide band hard ware and soft ware in the very context. The algorithm scheme mitigates the impact of non-line of sight ranging errors on positioning accuracy without any additional protocol hook. More particularly, the realistic IR-UWB ranging error models we use take into account UWB channel effects, as well as relative clock drifts. By error analyzing and simulation under the proper operation model, results are provided to illustrate the relevance of such a solution.
Applications of the finite element method in the ultrasonic flow measurement
Yiding Zhao, Shuhua Ma
Most of the measuring flow methods are either based on experiential formula or multi-ultrasonic transducers. The former has the disadvantage of underestimation of errors while the latter adopts multi-channel data and higher cost of equipment, which is limited in the application in engineering. The finite element method is adopted to mimic the numerical value of the flow velocity field of the transect of liquid such as water in ditches of various regular shapes. In order to make a reasonable simplified analysis of the flow velocity model, ignore the inertial force of the flow in the calculation, the flow field is a potential flow with a free surface. If the flow in the ditch is simply treated as a incompressible viscous flow, the model can be considered as a problem of two dimensional irrotational incompressible flow. The ultrasonic kinemometer is used to measure the velocities of water of different depth in ditches. The velocities are used as the boundary conditions of the finite element method. Only to measure a few flow velocities of different depth, can the flow value of the transect be obtained easily by the finite element method.
Study on multiphase flow online metering models without separation
Fuxian Zhou, Yuxing Li, Huimin Yang, et al.
Multiphase flow metering is very important in the oilfield. We construct four new liquid metering models (Falling Model I, Falling Model II, Open Channel Model and Element Resistance Model) and a gas metering model based on the online multiphase flow metering equipment without separation. The experimental study was carried on indoors at the multiphase flow metering equipment, and the model coefficients can be figured out by the method of date classification. We can figure out the error of each phase, and evaluate all the metering models. Through errors analysis, the average error of the liquid metering models can be within 10%. The error of gas metering model can be controlled within 20%. The experiment results proved that these metering models can be used in the multiphase metering with different viscosity. The metering precision is rather high in the wide range of gas phase and liquid phase flow rate. And it fits in with outdoor application.
Research and implementation of a special signal source of open-loop testing system of resonant microsensor
Shangchun Fan, Yijun Wang
As a core component for open-loop characteristics testing system of micro-sensor, quality of signal source influences the integer performances of testing system directly. The method to generate special signal of open-loop testing system of resonant micro-sensor are discussed in this paper, and a method of direct digital frequency synthesize (DDS) to develop the special signal source of the testing system is proposed. A designation approach based on DSP and FPGA in the realization of DDS is advocated. Finally a simulation is made using the MATLAB. The principle of DDS is also introduced.
Design and implementation of a 3-lead ECG wireless remote monitoring system
Shi Zhang, Xiaonan Jia, Shuai Shang
Cardiovascular disease is one of the main diseases that menaces human health. It is necessary to monitor the patient's real-time electrocardiograph (ECG) for a long time to realize diagnosis and salvage. Remote ECG monitoring system is the solution. This paper introduces the design and implement of a 3-lead ECG wireless remote monitoring system. It collects, stores and transmits user's ECG which can be received by hospital and diagnosed by doctors. The development of the whole system contains three parts, the hardware and embedded software implementation of MONITOR, software of the MONITORING CENTER, and the routing software of NETWORK CENTER. According to the clinic experimentation, this system has high reliability and utility. There will be great social and economic benefit if this system is put into use.
The test and analysis of excitation stress on omni-axis shaker
Yingyang Yu, Hongjie Yuan, Tongmin Jiang
Traditional simulating testing has been evolving into reliability stimulating testing. Reliability enhancement testing, an important stimulating method, can make design more robust by improving the product's reliability. In the reliability enhancement testing, omni-axis shaker is always used only because it can provide multi-axial accelerations (X, Y and Z) and six degrees of freedom simultaneously. This paper samples the vibration data on the omni-axis shaker of X, Y and Z axes from different positions under different excitations by a real-time measuring way, and conducts the stationarity, periodicity and normality checking on the basis of the acquired date. The characteristics of frequency domain, peak probability density, higher moment statistics and super-Gaussian of omni-axis shaker are analyzed. This paper shows the future development direction of reliability enhancement testing through analyzing the advantages and disadvantages of omni-axis shaker.
Borehole survey system using fiber optic gyroscopes strapdown inertial navigation
Shuang Gao, Chunxi Zhang, Tingyang Yan, et al.
This paper will present a Fiber Optic Gyroscopes Strap down Inertial Navigation System (SINS) used in borehole survey systems. This system can be used for Wire-Line logging operations because of Fiber Optic Gyroscope's excellent capabilities of long life time, ruggedness, compactness, low cost and high environmental insensitivity. This borehole survey system utilizes the cable length signal aiding Fiber Optic Gyroscopes Strapdown Inertial Navigation System. Furthermore, this system utilizes an optimal estimation procedure based on Kalman filtering method to estimate and compensate the system errors on-line. This paper also presents a cable length model to correct the cable length signal. Simulation results show that the methods can effectively enhance the precision of the borehole survey system. In this system, the borehole survey system can fleetly and continuously survey the borehole during Wire-Line logging operations for determining the precise path of the borehole. Moreover, due to the compact frame of IMU, the borehole surveying system can be used for determining the small diameter boreholes.
Online measurement of fouling in steam condenser based on character selection and fuzzy modeling
Shaosheng Fan, Xiaohua Wang, Hong Li
A novel method based on character selection and fuzzy modeling is proposed in this paper. In the method, sensitivity calculation based on BP neural network is introduced to determine the most suitable character variable which reflects the fouling state. T-S fuzzy model is employed to separate the influences imposed by fouling on character variable from other factors. During fuzzy modeling, a fuzzy clustering algorithm based on similarity assessing is proposed to determine the optimal model structure, which makes the measurement model compact, accurate and robust. Based on the method, an experimental system is developed and experiment on an actual condenser is carried out. The results show the method measures fouling correctly, and is more effective than thermal resistance method or heat transfer coefficient method.
Error analysis and compensation of a strapdown inertial continuous surveying system
Qiying Kong, Jianhui Zhao, Fan Li
Gyroscopic surveying system utilizing one dual-axis dynamically tuned gyroscope and two accelerometers has been suggested to work at continuous mode to improve surveying efficiency. Investigation of how various error sources influence on the accuracy of the new continuous surveying system is helpful when finding ways to enhance the longterm performance. This article aims at analyzing the surveying errors associated with proposed continuous surveying algorithm, including algorithm errors, sensor errors, etc. The influence of each source on surveying result is formulated. It also offers some techniques to enhance the long-term surveying accuracy. The algorithm is modified to improve the toolface angle surveying accuracy. The biases of gyro and accelerometers are periodically modulated by continuous rotation. The modulated output signals are sampled and disposed, then surveying errors are reduced. Simulation results indicate that suggested methodology significantly improved the surveying accuracy.
A low cost barcode recognition method
Ying Hu, Jin Huang, Zi Ma
Traditional barcode recognition equipments are very expensive and very often do not fit common users due to their large scale. A novel low-cost method is proposed in this paper to implement automatic recognition of the barcode information from images captured by a CMOS camera without the need for additional light source. Firstly, the barcode orientation is recognized based on the character of bar-like image. The barcode sequence is then generated by the image projection. Finally, the barcode information is recognized according to the encoding rule. The overall success rate is up to 90%, justified by 400 datasets provided by multiple individuals.
Sensorless control of electrical drives
Junkui Wang, Bo Yang
This paper provides an overview of advanced methods to perform sensorless control for D.C. and A.C. motors in detail. The features of the methods are presented, analyzed and evaluated. The conclusion can be used as a guideline for the persons interested in sensorless control.
Study of multi-acoustic channel supersonic Doppler flowmeter for measuring coal slurry-coal log pipeline
Yu Lin, Jie Yang, Jun Tang
Coal slurry-coal log pipeline is a new technology for long distance transportation of coal logs (cylindrical coal briquettes) by using coal slurry as carrier and pump as power set. Because of the difficulty of measuring flow rate of coal slurry-coal log pipeline, the study of measuring technology and the development of flowmeter are necessary. In consideration of the characteristics of transportation of coal logs in coal slurry pipeline, a non-contacting measuring method and the supersonic Doppler effect are selected and used. By detecting frequency drifts produced by reflecting supersonic wave from moving coal particles and coal logs in pipeline the flow rate of coal slurry-coal log pipeline (the total quantity of coal transported by the pipeline) can be measured. Based on the concept of liner concentration of coal logs in pipeline and characteristics of Doppler frequency drifts of coal particles and coal logs moved in pipeline, the measuring method of supersonic wave and the transportation principle of coal slurry-coal log pipeline are discussed and a multi-acoustic channel supersonic Doppler flowmeter is designed for measuring the total quantity of coal transported by pipeline. The flowmeter is composed of supersonic transducer, electron circuit, flow rate indication and integral calculation system. The multi-acoustic channel technique and a suitable acoustic wedge with a certain shape and special solid material are selected and used for increasing the measuring precision. In this paper the Doppler signal is measured and analyzed by using mixing-frequency technique and FPT (rapid Fourier transformation), and some designed circuits and signal measurement process are also offered.
Indirect measurement of NMR scalar coupling constants under inhomogenous magnetic fields
Yanqin Lin, Xu Liu, Song Chen, et al.
Scalar coupling constant is an important parameter in structure analysis from nuclear magnetic resonance (NMR) spectra. However, it is difficult to obtain in inhomogeneous fields using general NMR techniques due to broadened line-width. Since the line-widths of intermolecular zero quantum coherence (iZQC) spectrum only depend on the relative inhomogeneity within the correlation distance in the sample, scalar coupling constants can be gained though one-dimensional spectra from the projection of two-dimensional iZQC spectra onto the indirect dimension. However, the existing pulse sequences are not suitable for various spin systems because of the great difference in scalar coupling constants and line denseness in spectra. To solve this problem, a new pulse sequence, which can scale scalar coupling constants, was designed by adding a refocusing π pulse in the indirect detection period (corresponding to indirect dimension). According to specific spin coupled system and spectral condition, precise coupling constants can be indirectly measured by selecting a compromise scaling factor for coupling constant.
Pitch calibration of one-dimensional grating standard by tapping mode nanometrological atomic force microscope
Qiangxian Huang, Ichiko Misumi, Satoshi Gonda, et al.
A tapping mode nanometrological Atomic Force Microscope system with an ultra-high resolution three-axis laser interferometer was introduced. In the nano-metrological AFM, laser interferometers are used to measure and control the relative movement between probe tip and sample, and the AFM can reach very high accuracy. By the tapping Mode AFM, the pith of a grating standard was calibrated. The sources of uncertainty were analyzed and the corresponding uncertainty components were given. According to the analysis and calculation, the most reliable value of the grating pitch with nominal value of 240 nm and its combined standard uncertainty are 240.024 ± 0.157 nm.
A novel transient electromagnetic measuring system
Zhihong Fu, Rui Sun, Qiang Luo, et al.
Transient electromagnetic measuring system, a kind of geophysics detecting devices, still have some technological problems unsolved in high current steep pulse transmitting, high precision synchronous control, large dynamic range signal gathering, etc., This paper proposes a novel transient electromagnetic measuring system(WTEM) with some technological improvements, including: (1) applying PocketPC and Bluetooth wireless technology in receivers to improve the system performance and reduces the receivers scale; (2) constructing a steep pulse transmitting circuit to output high current pulse with high linearity falling edge, short shut-off time and fast rising edge, finally improving the surficial resolving power; (3) proposing a GPS synchronous controller with high synchronous precision, in which TCXO working with GPS corporately, recovering the short-time invalidation of GPS module. In the project of detecting the oil pipeline corrosion, indoor and field tests have been done to WTEM system. The results indicate that WTEM possesses fine performances, short withdrawing time from saturation status, high synchronous precision and short turn-off time of transmitting current, etc..
A new method of accelerated graph display in primary flight display based on FPGA
Quancun Kong, Chenggui Li, Fengqing Zhang
With the development of avionic technology, there is the increasing amount of information to be displayed on Primary Flight Display (PFD) of the cockpit. Beside the higher requirement of accuracy, reliability and the real-time property of information should be met in some emergency situations. Therefore, it is rather important to make further improvement on speeding up graph generation and display. This paper, based on hardware acceleration, describes a designated method to satisfy the higher requirement of PFD for graph display. The new method is characterized with graphic layering double frame buffer alternation and graphic synthesis, which to a great extent, reduces the job of a processor and speeds up the graphic generation and display, hence solving the speed bottleneck in PFD graphic display.
Application of LABVIEW and LABVIEW FPGA module in serial communication of satellite-ground associated test system
PingHua Wang, ChengGui Li, Miao Ma
This paper presents a new method of FPGA design that a custom virtual instrument was created and downloaded to the user-reconfigurable FPGA on the NI PXI7831R by using LabVIEW, a graphical programming environment, and LabVIEW FPGA Module. The FPGA was designed as multi-channel synchronous serial ports and asynchronous serial ports. And the drive program of which were built in Labview for Windows to DLL called by the main test program running on DSC (dynamics simulation computer). The module and device completed multichannel serial communication between DSC and GNCC (gesture navigation control computer). It provided a dynamic close-looped debug and test environment for the Satellite-Ground Associated Test System so as to verify the validity of the program running on GNCC, the accuracy and integrality of the whole system. The potential bugs of software could be also found ahead.
Measurement and calculation for real-time oscillation frequency and phase of the slab caster mold
Zhixin Chen, Qizhong Cai
This paper presents the methods in designing and implementing real-time measurement system of oscillation parameter, based on the oscillation orderliness using in slab caster mold. From practical operation, the software can be manipulated easily and steadily. Using the software, the measurement, calculation, display, alarm and storage of oscillation state can be finished fleetly and accurately under different drawing speed. The gist is put forward in order to improve quality and quantity of slab using slab caster, judge the abrasion of drive system, the warp of leading system and other system failure.
Error analysis of the articulated flexible arm CMM based on geometric method
Xueying Wang, Shugui Liu, Guoxiong Zhang, et al.
In order to overcome the disadvantage of traditional CMM (Coordinate Measuring Machine), a new type of CMM with rotational joints and flexible arms named articulated arm flexible CMM is developed, in which linear measurements are substituted by angular ones. Firstly a quasi-spherical coordinate system is put forward, the ideal mathematical model of articulated arm flexible CMM is established. On the base of full analysis on the factors affecting the measurement accuracy, ideal mathematical model is modified to error model according to structural parameters and geometric errors. A geometric method is proposed to verify feasibility of error model, and the results convincingly show its validity. Position errors caused by different type of error sources are analyzed, and a theoretic base for introducing error compensation and improving the accuracy of articulated arm flexible CMM is established.
Design and optimization of a novel resonant accelerometer resonator
Shangchun Fan, Zhiping Peng
MEMS resonant accelerometer has been proved to be a delicate accelerometer with high performance. Mechanical resonator is the core component for the design of MEMS resonant accelerometer. With the development of surface micro-machining and bulk micro-machining technology, the silicon resonator has expanded its use to micro-accelerometers. Two resonator structures of non-fork-ends-extension and fork-ends-extension with four kinds of key component structure electronic parameters are designed. The resonator consists of two DETF tuning forks fixed by two anchors; the fixed and movable combs and the necessary attachable structure such as convex table-board. FEA (finite element analysis) method was used to simulate the working condition with the consideration of the silicon micro machining property and feasibility. It reveals that the novel resonate accelerometer is characterized of high sensitivity through theoretical analysis and simulation on entire structure.
GPS estimation of uncertainty in three-dimensional flatness measurements
Yonghou Sun, Ya Zhang, Meifa Huang, et al.
Improved Geometrical Product Specifications (GPS) standards system is the foundation of the technology standards and metrology specifications of mechanical and electric products. GPS estimation of uncertainty should assure the integrity and reliability of the verification result of products. According to the requirements of the improved GPS system, the decision rule based on compliance uncertainty is adopted in this paper to decide whether the flatness can be accepted or not. Then the calculation equation of compliance uncertainty in three-dimensional flatness measuring process is deduced based on the basic principle of least-square verification and the transparent box model given in ISO/TS 14253-2. An experimental research is also given to validate the method proposed in this paper.
A novel method for uncertainty evaluation of roundness errors based on geometrical product specification
Jian Mao, Yanlong Cao, Jiangxin Yang, et al.
Roundness of circular and cylindrical parts can greatly affect assembly accuracy. It is essential to establish a proper method for evaluation roundness error to ensure achieving accurate assessment. According to the evaluation principle of roundness error and the uncertainty theory, a novel method for the uncertainty evaluation of roundness errors is proposed based on the new generation geometrical product specification (GPS). Under the condition of minimum zone, the mathematical model of roundness error and the optimal objective function were developed. Particle Swarm Optimization (PSO) algorithm was used to search for the optimal solution of roundness error. The uncertainties of each of coefficients which influenced the roundness error and of transfer coefficient were calculated in order to get the uncertainty of roundness error. The evaluation results accord with requirements of new generation GPS standard and indicate that this method can assure the integrity and veracity of evaluation.
Angular acceleration calculation method on non-gyro inertial measurement unit
Fengjia Sun, Shangchun Fan
With the development of technology, it is very important to measure the parameter of angle. This paper gives an introduction of basic principle of Non-gyro Inertial Measurement Unit. According to the theory of geostatics, Arithmetic and basic principles of NGIMU are given. In describing the movement of rigid body, we suppose an inertial frame and revolving frame, the expression of angle acceleration is given by the arrangement of linear acceleration. The application of arithmetic and basic principles is given in the paper, calculating the single angle acceleration by three linear acceleration and processing the signal through analog filter, amplifier and digital filter, then discussing the possible problem in practicality.
Calibration method with grating grooves based on precision vision measurement
Yingwu Xue, Yuning Zhong, Xuanze Wang, et al.
This paper presents a new method of high-precision calibration with grating grooves for precision vision measurement system of micro-size part. After an image of high precision grating grooves are grabbed by CCD, a black-and-white striped picture may be gotten. A group of data being similar to sinusoid is gotten by calculating the sum of gray-value of pixels in each column. These calculated data are elaborately showed a Lissajous figure in one plane by translation for pixel. The size mapping coefficient between the grating groove and their image pixels of the optical measurement system is calculated by analyzing and processing the Lissajous figure. It is not necessary to calculate the interior and exterior parameters of the camera for the calibration of measurement system when this method is adopted. Finally, this paper gives the result of calibration and its error analysis for one optical system.
Study on the method of roundness error measurement based on GPS operation technology
Kewei Qing, Linna Zhang, Peng Zheng, et al.
With the development of the measurement techniques, especially the precision and ultra-precision measurement techniques, the measurement process of the geometric error based on the old GPS (geometrical product specification and verification) technology can hardly meet the requirement of high accuracy and efficiency. A new GPS system which was introduced by ISO/TC213 and based on metrology, has unified the whole process of product's specification and verification, and also realizes the digitized and standardized measurement. It provides a new approach to the measurement of the geometrical error by using the operation and operator technologies. In this paper the application of the operation technology in roundness error measurement is described in detail, moreover, the method and the key technique of realizing the process are also put forward. Lastly, by designing the appropriate verification operator of roundness error, the measurement process is specified and the measurement uncertainty is also decreased.
Research on applying constant current to control the EOF in microfluidic chips
Mingjing Yang, Chong Liu, Jingmin Li, et al.
The difference of controlling the electroosmotic flow (EOF) in microchip electrophoresis between applied constant current and constant voltage is compared in this paper. We can deduce that the current in microchannels indicates the velocity of the EOF more directly than the voltage applied on reservoirs. So controlling the EOF in microchip electrophoresis by the current in microchannels will be more convenient than applying voltage on reservoirs. A constant voltage/current dual-function high voltage power supply (HV power supply) has been designed with Micro-Computer Control Unit (MCU) for our study. The HV power supply has quadruple outputs. The PMMA microfluidic chips with double "T" layout are used in the experiments of microchip electrophoresis in this paper. They are applied with constant current control mode and constant voltage control mode respectively. In result, the same current program has better adaptability than the voltage program to microfluidic chips with different size.
A digital control system of brushless DC motor based on programmable logic device
Jianke Li, Gang Liu, Jiancheng Fang
A digital control system of brushless DC motor based on programmable Logic Device GAL16V8 and DSP is researched, and the principle and every element of the control system such as DSP2407,Logic handling segment, power driving circuit are analyzed. Compared with the software communication of BLDCM based on DSP, the control system has fast dynamic response, high reliability. The experimental result shows that the system has satisfied the spacecraft's demands on the BLDCM driving flywheel. In the end, the problem exited in the control system is analyzed on theory.
A PC104 architecture-based high-accuracy laser diode alignment system
Qingshan Chen, Naiguang Lv, Zhikang Pan, et al.
Reports a laser diode alignment system for monitoring dam, building, bridge, etc. It comprises a light source and a receiving unit. The former is mainly composed of a laser diode for emitting light in red spectrum band at wavelength of 680nm, a single mode fiber for spot transforming and mode selecting, and a reverse telescope for collimating the emission light beam. The whole light source is mounted on a 4-dimension adjustable table fixed on a tripod. The latter is an embedded computer based on PC104 architecture. It contains a mainboard, an image grabber, a LCD display and a CCD. Central position of the light spot is calculated according to barycenter method. It is proved by experiments in lab that within a span of 8m the direction stability of the alignment system is up to 1X10-6 magnitude order.
The MSP430-based control system for automatic ELISA tester
Xinghua Zhao, Lianqing Zhu, Mingli Dong, et al.
This paper introduces the scheme of a control system for a fully automatic ELISA (Enzyme-linked Immunosorbent Assay) tester. This tester is designed to realize the movement and positioning of the robotic arms and the pipettors and to complete the functions of pumping, reading, washing, incubating and so on. It is based on a MSP430 flash chip, a 16-bit MCU manufactured by TI Co, with very low power consumption and powerful functions. This chip is adopted in all devices of the workstation to run the controlling program, to store involved parameters and data, and to drive stepper motors. To the MCUs, motors, sensors, valves and fans are extended. A personal computer (PC) is employed to communicate with the instrument through an interface board. Relevant hardware circuits are provided. Two programs, one running in PC performs users' operation about assay options and results, the other running in MCU initiates the system and waits for commands to drive the mechanisms, are developed. Through various examinations, this control system is proved to be reliable, efficient and flexible.
The separation and assessment methods of the helix feature line of helicoidal surfaces
Yafei Yan, Lianqing Zhu, Mingli Dong, et al.
The measurement of helicoidal surfaces is very important for the manufacture and utilization of fine mechanical parts. It usually employs the feature line error to represent the helicoidal surfaces' error. Two methods, commonly used to assess the character line error, least-square method and accumulative sum method, are analyzed and compared here by combining with practical data processing.
Design of three-phase power network multi-function measurement instrument based on AT73C500
Xiaoqin Lian, Yelan Wu, Qun Hao
Three-phase power network multi-function measurement instrument was designed to measure current, voltage, frequency, power factor, active/reactive, apparent power, and etc. which adopted ATMEL DSP-based power metering chipset AT73C500 and AT73C501. The design method based on ATMEL microchip AVR8515 was introduced, and the causes of measurement errors and calibration methods were discussed. The test results show that the accuracy of the measuring instrument is of class 0.5.
Photo-Electronic Technology and Instrumentation
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Sensing with holey optical fibers
Wei Jin, Yi-Ping Wang, Jian Ju
We report our recently research on holey optical fiber sensors, including gas detection using hollow-core and solid-core silica holey fibers, two-mode holey fibers and their applications in strain and temperature measurements, long period gratings inscribed on holey fibers and their strain and temperature characteristics.
Research of the impact of slanting installation error of PSD on spot position
Hongyan Shang, Guangjun Zhang, Zhenzhong Wei, et al.
For the problem of the impact of slanting installation of PSD used as photoelectric detector on spot position, a mathematical model of this distortion error of the spot position is established and the simulation is done. Some conclusions show that the distortion error of the spot position increases with the increasing of slanting angle of PSD surface, beam waist radius and distance between PSD and beam waist position. The effect on spot positioning precision of foregoing two can be ignored in a little range, and the last one has great effect. The distortion error model of spot position and simulative results provide an available theoretical reference for the actually engineering applications of PSD.
Analysis for the transmission spectrum character of phase-shift long period gratings
Dandan Zhu, Zhiquan Li, Yan Li, et al.
Transmission spectrum of phase-shift long period gratings is analyzed by transfer matrix method. Through simulation experiments, the effects of grating parameters (period and length, average index modulation, the phase-shift position) on the phase-shift long period Gratings are discussed. The rule of each parameter effect the transmission spectrum is discussed. We draw a conclusion that if we select suitable grating parameters, we can get the special transmission spectrum for the application.
A simple but high-precision registration method in 3D vision measurement
Limei Song, Mingping Wang, Lu Lu, et al.
3D vision measurement is a popular technique to solve non-contact and non-destructive measurement task. In any 3D measurement technology, registration is a very important procedure to put two adjacent but different areas into one area. And it is a key step to ensure the final 3D measurement precision. Most algorithms used to solve the registration problem can be classified to either area-based techniques or feature-based techniques. Feature-based technique is the most commonly used method in 3D and 2D registration. Some flags may be pasted or signed on the entities in order to make the common area easy to be identified. A lot of researcher focus on feature-based technique, and present some algorithms to compute the rotation matrix and translation matrix, to solve the registration problem. But the registration effect is poor and the object usually distorts its real shape. We present a novel registration method, without complex algorithms; just use the searching merits of computer program. Rotation matrix is computed by three key angles Ψ, θ, and Φ. If these angles are found with high precision, the rotation matrix will be confirmed. Then the translation matrix can be calculated using the coordinates of three common points. From a lot of experiments, the proposed registration method is proved that it is a simple, easy programmed, easy operated, and with high precision. Furthermore, it can be widely used in any other 3D measurement system.
Study of the thermal characteristic of x-ray mask during short-pulsed exposure
Hongyan Shang, Yongkun Wang
Three-dimensional finite element short-pulsed models of X-ray mask have been developed and the energy absorption function along the mask thickness direction has been considered. The results show that the absorber's temperature is higher than the substrate's because the absorber has higher absorption coefficient. In addition, the lower the absorber coverage of the mask, the lower the mask temperature is. The transient simulation results show that the mask temperature reached the maximum at the end of the short-pulsed exposure. It occurs at the interface between the substrate and the absorber, and the maximum is 52.7°C.
Influence of piezoelectricity on the vibration errors of interferometric fiber-optic gyroscope
Yan Li, Chunxi Zhang, Hongjie Xu, et al.
Vibration errors of fiber optic gyroscope (FOG) affect its application performance directly. According to the Y waveguide integrated optical modulator, and based on the piezoelectricity characteristic of LiNbO3 crystal, the affixed voltage caused by vibration was analyzed theoretically. The expression between the vibrating acceleration and the voltage produced on the electrode of waveguide was conducted. At the same time, in accordance with the Pockels effect, the phase error caused by the voltage in the interferometer was achieved. Vibration errors, caused by vibrating accelerations which is single frequency, were simulated by computer. The conclusion that the error caused by piezoelectricity is one of the vibration errors is achieved.
Scanning white-light interferometry for microstructures geometrical characterization
Tong Guo, Chun-guang Hu, Jin-ping Chen, et al.
Scanning white-light interferometry (SWLI) surface profiling for geometrical characterization and device inspection is described in this paper, which is quick, non-destructive, non-contact, and easy to carry out at the wafer scale with sub-micrometer lateral resolution and nanoscale vertical resolution. The measurement system is based on a Mirau microscopic interferometer, using a piezo objective nano-positioner to realize accurate scanning in vertical direction in the range of one hundred micrometers. It employs the method called centroid algorithm to extract the envelope peak position. Comparing with phase shifting interferometry, it has a large measurement range. The measurement accuracy of the system is calibrated by a step height standard which is certificated by NIST. A micro resonator is employed to illustrate the capabilities of SWLI as a measurement and process characterization tool.
Nanoscale measurement technique of in-plane motion for MEMS based on phase correlation method
Zhi Chen, Xiaodong Hu, Cuiyun Jin, et al.
In order to measure motion characteristic and dynamic parameters of MEMS resonator in every moment based on the techniques of stroboscopic imaging clear motion images for every moment in one cycle are obtained. Using technique of Phase correlation method to process motion images of MEMS resonator the dynamic parameters are got. The results give important reference to MEMS designation. In this paper we derive a completely analytical N-cubed algorithm based on Phase correlation method. MEMS motion process is analyzed using the algorithm. The amplitude-phase curve of MEMS in special driving frequency is got. The phase-frequency character is also analyzed. And the amplitude-frequency curve is acquired through sweep frequency measurement. Experimental results indicate that the repetition of measurement is 5nm.
Bandwidth measurement of digital closed-loop fiber optic gyroscope based on Faraday effect
Zhanjun Wu, Chunxi Zhang, Xiaoxiao Wang, et al.
Bandwidth of fiber optic gyroscope (FOG) was a parameter that can not be fully measured at present. Measurement range of the traditional method (based on the dynamic test turn table) was several hundred Hertz, could only measure low frequency section of the FOG. To solve this problem, proposed the measurement principle based on the magneto-optic Faraday effect of the FOG. The finite element transmission model of the fiber coil was established. Derived the Faraday effect output model of the FOG under the high birefringence optic fiber and packaged fiber coil were used. The Faraday effect output of FOG is proportional to the magnetic field intensity. Based on the detection principle of the FOG, the equivalence of this method and the traditional method was analyzed. High frequency magnetic field could be easily obtained by using high frequency current, the measurement range can cover the bandwidth of the FOG. Established bandwidth measurement system, frequency is more than 50 kHz and distortion is less than 0.1%. The measurement results were presented. Magnitude-frequency and phase-frequency figure shows that the bandwidth of FOG with 1500 m length fiber coil is about 2.1 kHz. This method can solve the low frequency output disadvantage of the dynamic test turn table and test the whole bandwidth frequency response of the FOG.
Method of video capture port design for IP camera
Li Zhang, Shuangchen Ruan, Min Zhang, et al.
The IP surveillance market is growing significantly and is receiving global attention now. IP camera is the heart of this new surveillance system. As the key component of IP camera, video capture port contributes greatly to camera's cost. CCD image sensors are employed in most IP camera for its excellent performance and maturity in the market. In fact, new types of CMOS image sensors have become possible recent years due to CMOS technology improvements. This paper presents a design of an IP camera's video capture port using CMOS image sensor based on embedded environment. Also contained is a brief introduction to the hardware design including the interface and PCB layout. The paper also provides information on setup of important registers, functions usage and debug tips. The design was tested on an IP camera which has been on market for three years. The results show that using CMOS image sensor can achieve good image and save cost. Therefore, it is well suited for the surveillance field where image resolution is not the focus. The method can easily be extended to any other IP camera design with little change both in hardware and software.
A micro-adaptive optics system for aberrated laser beams compensation
Jie Li, Haiqing Chen, Tao Wu
Many high power lasers typically suffer from reduced beam quality due to thermally induced aberrations. Adaptive optics is an effective way to compensate the dynamic aberration. But adaptive optics has not found widespread acceptance due to the cost and complexity. It is not until recently that can the problem be readily solved with the development of microelectromechanical systems (MEMS) based on silicon micromaching technology. Calculations are performed showing the effect of Zernike aberrations on laser beam quality. We describe an adaptive optics system based on a MEMS deformable mirror to compensate the thermally induced aberrations. From the test result, it is explicit that the adaptive system can correct the thermally induced aberration of high power lasers and increase the Strehl ratio to about 80% on average.
Research on dynamic characteristic of optical drive servo system with PLZT
Lei Liang, Shaoping Wang, Feng Cao
Traditional electric servo system is disturbed by electromagnetic interference, so optical servo system is needed to build urgently in order to avoid electric signal and electrical wire. Therefore, photostrictive ceramics becomes promising material to realize the optic-signal transmission and photostriction. Lanthanum-modified lead zirconate titanate (PLZT) ceramic is one of the most promising photostrictive materials that can stretch with the light intensity. Because the stretch of PLZT is only about 1μm irradiated by ultraviolet light in unilateralism, this paper adopts the bimorph and amplificatory pole to reach 100μm. The experimental result indicates that PLZT can be used to stretch the tiny displacement with light that dynamic characteristic can meet the requirement of optical drive. Especially, optical servo system used PLZT bimorph as servo valve is illuminated here. A simple on-off control is insufficient to control the optical actuator because the mechanical shutters controlling light irradiation have a large time lag, and the error is more than 0.5μm. A new control method, taking into account the dynamic responses of the PLZT bimorph in order to turn off the shutter or not, is introduced into the system and improves the precision, that is, the system error decreases to 0.1μm.
Vertical displacement stage with diffraction grating sensor
Suping Chang, Tiebang Xie, Rong Dai
To satisfy requirements of high accuracy and high resolution displacement in vertical scanning white-light interferometry and calibrations of precision sensors, a vertical displacement stage with nanometer resolution and accuracy is developed. A mechanism with flexural-hinge guided motion is utilized and driven by piezoelectric transducer for vertical micro-displacement in this stage. By lever magnifying part, the flexural-hinge mechanism implements two-grade displacement magnification, so the stage has a large range while it has high accuracy and high-resolution. Due to the hysteresis and nonlinear characteristic of PZT, the whole displacement process is monitored by a diffraction grating sensor and compensated in real-time. The deflection influences of the diffraction grating on the vertical displacement are analyzed and some experiments are carried out to verify the characteristics of the stage.
Development of a new diffuse near-infrared food measuring
Jun Zhang, Renguan Piao
Industries from agriculture to petrochemistry have found near infrared (NIR) spectroscopic analysis useful for quality control and quantitative analysis of materials and products. The general chemical, polymer chemistry, petrochemistry, agriculture, food and textile industries are currently using NIR spectroscopic methods for analysis. In this study, we developed a new sort NIR instrument for food measuring. The instrument consists of a light source, 12 filters to the prismatic part. The special part is that we use a mirror to get two beams of light. And two PbS detectors were used. One detector collected the radiation of one light beam directly and the value was set as the standard instead the standard white surface. Another light beam irradiate the sample surface, and the diffuse light was collected by another detector. The value of the two detectors was compared and the absorbency was computed. We tested the performance of the NIR instrument in determining the protein and fat content of milk powder. The calibration showed the accuracy of the instrument in practice.
Study on the polarization of light scattered from nonspherical particles
Yiming Zhao, Yuesong Jiang, Wenhui Rao, et al.
The study on the scattering characters of the targets scattered by the polarized light, is a very important approach to study the characters of the targets. Based on the scattered model of the non-spherical particles, the Mueller matrix can be calculated using the vector radiative equation. The change of the polarization degree vs. parameters of the scattered medium will be discussed in this article.
Research on the fiber reflecting sensor for detecting the residual capacity of the lead-acid battery
Mingfu Zhao, Nianbing Zhong, Yan Chen, et al.
According to the Lambert-Bee law, we can see that the photic absorption coefficient is related to the matter's concentration, the distance of the light through the absorption medium and the transmitted light intensity. The paper just according to the physical phenomena and the theory make the reflex energy relate to the concentration testing of the electrolyte, at the same time the electrolyte's concentration is related to the capacity of lead-acid battery on a corresponding function relation, so we can know the capacity state of the lead-acid battery according to the measurement on the electrolyte's concentration. According to the experiment and research the author deeply discussed how the temperature change affects the capacity of lead-acid battery and the concentration's changing relation, according to the analyses of the thermo-optic effect, we made a new reflecting fiber sensor based on the comparative temperature testing theory and absorption which can eliminate the temperature effect on the tested signal namely the output signal just related to the concentration, so really reflects the change of the capacity of the lead-acid battery when it is in the charge and discharge process. The results of the experiment and theory analyses show that this method is easy to realize the online testing of the capacity of lead-acid battery. This sensor has many merits such as precise measurement, sensitive reaction, long-life use etc. It can be widely used in the electric capacity testing of the automobile lead-acid battery, the electric capacity testing of the industry lead-acid battery, liquor's concentration testing and salinity testing of the sea and have a bright future.
The method study of biomass consistency based on the fiber online test
Mingfu Zhao, Qiang Liao, Yan Chen, et al.
In a biological system which contains microbial bacterium liquid, we set a fiber attenuation measuring system. The change of the biomass concentration will affect the change of the light absorption and light scattering, and then change the receiving power. The paper bases on this physical phenomena and theory, makes the receiving power relate to the biomass' concentration testing and set up a new method to measure the biomass concentration. The paper describes the sensor's composing theory, the light path analyses and its theory explanation, at the same time deeply discusses that how the biomass changes in the near infrared circumstance. The experiment results and analyses show that this method is linear well to measure the microbial liquid concentration, it have many merits such as precise online testing, high sensitivity and long life use etc. The sensor's design theory and method is meaningful to be used on the preparation, making alcohol, microanalysis, biochemistry and environment protecting etc. It is a practical new style biomass concentration sensor and has a bright future.
A three-zone pulse-only pupil filter for improving lateral resolution
Lirong Qiu, Weiqian Zhao, Dingguo Sha
In order to achieve the lateral superresolution imaging of an optical imaging system, a three-zone and multi-values phase-only pupil filter is designed to achieve the superresolution of full width at half maximum GL=0.65, Strehl ratio S=0.118 and ratio of maximal side lobe intensity with pupil and main lobe intensity without pupil M=0.912, which is based on pupil filter techniques and uses genetic optimizing algorithm. A three-zone phase-only pupil supperresolution confocal microscopy imaging method is established by integrating the three-zone and multi-values phase-only pupil filter designed with confocal microscopy system (CMS). Simulation results indicate that, when CMS lateral superresolution of GL=0.56, S=0.118 is achieved, the approach proposed can suppress the increasing of side lobe M caused by three-zone phase-only superresolution pupil from 0.912 to 0.02, and obviously improve CMS lateral resolution and imaging quality. A three-zone and two-value phase-only pupil filter is also designed, and its central intensity is slightly smaller than that of the multi-values pupil designed for the same G, however, its process technology is superior, it is better for practical application. It is therefore concluded that the design method proposed provides an effective technical approach for the design of superresolution pupil filters.
Phase-only pupil filtering confocal measurement system with higher lateral resolution
Lirong Qiu, Zhengde Feng, Dingguo Sha
Phase-only pupil filtering confocal microscopy (PFCM), a new approach is proposed to achieve a higher lateral resolution required for ultraprecision measurement of microstructural workpieces, which uses a three-zone phase-only pupil filter with lateral superresolution capability obtained through optimized design to change the confocal microscopy system's (CMS) distribution of three-dimensional point spread function, so that the CMS lateral resolution is therefore significantly improved while its axial resolution is slightly improved. Preliminary experimental comparison and analyses indicate that, the lateral and axial resolutions of PFCM are better than 0.2μm and 2nm, respectively, when λ= 632.8 nm, NA=0.85 and lateral spot size with a three-zone phase-only pupil filter GT=0.65.
A new arrangement method for photoelectric cells and its application
Yurong Chen, Xudong Yang, Xuanze Wang, et al.
Traditional photoelectric detection methods consider the interference fringes are evenly intensity distributed without random noise and the photoelectric signal satisfies the requirement of counter and subdivision in theory. However, in order to improve the Signal-to-Noise Ratio of detection, not only the requirement of counter and subdivision, but also the space arrangement of photoelectric cells must be taken into account. This paper presents a new arrangement method of photoelectric cells. The four adjacent photoelectric cells of the new method are arrayed in a square photoelectric cell array that inclines from the direction of the interference fringes with a certain offset angle. The new method and the traditional method are analyzed by integral equations and three models of random noise, AC amplitude and DC adrift are founded in this paper. According to the theoretical and experimental analysis, the detection Signal-to-Noise Ratio of the new method is improved remarkably compared with the traditional methods. This new method, which can dramatically restrain DC adrift of light intensity even if the fringes' signal is faint, can be applied in a laser-interference sensor for three-dimensional surface topography measurement.
The light pen of a no guide 3D-coordinate measuring system
Xiaofang Zhang, Chengzhi Jiang, Tongze Xue, et al.
With the advantages of simple structure, high speed, and high accuracy, a no guide 3D-coordinate measuring technique that using the photoelectric detectors with intersection converge imaging has the predominance in workshop measurement. Its measuring head is made in a pen shape with several light sources, which is called as the light pen. In this paper, the structure design and self-calibration of light pen system are analyzed, and the identifying way for multi-sources on light pen is present. The Laser-balls are offered to be the light-sources while the principles as well as fabrication are introduced. The light pen can insert and touch the points of inner surface in a deep hole. So the localization of CMM can be avoided by using the light pen with simple and deft structure.
Research of the new optical diffractive super-resolution element of the two-photon microfabrication
Peng Wei, Yu Zhu, Guanghong Duan
The new optical diffractive superresolution element (DSE) is being applied to improve the microfabrication radial superresolution in the two-photon three-dimension (3D) microfabrication system, which appeared only a few years ago and can provide the ability to confine photochemical and physical reactions to the order of laser wavelength in three dimensions. The design method of the DSE is that minimizing M if the lowest limit Sl of the S and the highest limit Gu of the G is set, where Liu [1] explained the definition of the S, M and G. Simulation test result proved that the microfabrication radial superresolution can be improved by the new optical DSE. The phenomenon can only be interpreted as the intensity of high-order and side of the zero-order diffraction peaks have been clapped under the twophoton absorption (TPA) polymerization threshold. In a word the polymerized volume can be chosen because the Sl and the Gu is correspondingly adjustable, even if the laser wavelength, objective lens and the photosensitive resin is fixed for a given two-photon microfabrication system. That means the radial superresolution of the two-photon microfabrication can be chosen.
Scanning interferometer for measurement of polarization cross-coupling in fiber-optic gyroscope
Xuefeng Wang, Wei Wang
In this paper, a scanning interferometer for measurement of polarization cross-coupling and its distribution in optic circuit of fiber-optic gyroscope is proposed and constructed, and the errors due to misalignment of principal axes of polarization-maintainning fibers and inaccurate rotation angle of Faraday rotation reflective mirrors are analyzed. A fiber spliced with three fiber segments and polarization-maintaining fiber coil are measured. Experimental results agree well with fact.
Simulation and experiment in focus system of wave-guide multilayer storage
Jun Li, Jiabi Chen, Peiming Zhang, et al.
The ultra-high speed processing and large storage capacity are the requirement of information technology. The multi-layer CD storage technology is used to enlarge the storage capability. In order to avoid some problem such as the crosstalk in different layer and the tracking of arbitrary layer, the dip-incidence and dip-reflection device is proposed in the focus system of wave-guide multi-layer CD. The improved astigmatism method is applied in focus system for better linearity. It can be proved by the simulation and experiment that the light intensity reflected from each layer is strong enough to receive; Moreover, only one layer's photospherical facula is leaved on the receiver for a size-limited receiver. It is identical with simulation result and sampled image signal in experiments. It can be proved by the focusing results of simulation and experiment that the signal of each layer is received and separated by the receiver.
Study of residual stress in porous silicon during drying
Jiran Liang, Ming Hu, Yilan Kang, et al.
Porous silicon has been extensively researched as an interesting photoluminescent material for photoelectric device integration. Residual stress often occurs due to capillary force during drying and results in warp, fracture and failure of the devices. Micro-Raman spectroscopy (MRS) has many special advantages of nondestructive, non-contact, high spatial resolution (1μm), broad spectrum range, Raman shift unaffected by the frequency of laser source, and ability to focus on a specific layer of sample. Furthermore, Raman spectrum is a powerful tool for the study of residual stress for its sensitivity to strain in the sample, which make it possible to measure residual stress directly. The underlying basis of micro-Raman spectroscopy for strain measurement is that Raman shift reflects the atomic spacing change, namely the strain information. The residual stress was measured during drying using Micro-Raman spectrum technology, the maxim is 3.6GPa. The relation of residual stress and Raman shift, drying times and FWHM were analysed, the capillary effect and the residual stress evolution from wetting to drying stages of porous silicon were investigated using phonon confinement model.
ZOCT and chaotic oscillator applied to fault section determination in distribution system
Qiufeng Shang, Wenchang Zhou
It's a new idea for using zero-sequence optical current transducer (ZOCT) to solve the measure problem of single-phase-to-ground fault section determination in distribution system. However the outputs of ZOCT are weak and mixed with noises, decreasing the detection sensitivity. Chaotic oscillator system is sensitive to certain signal and immune to noise, so the signal detection based on Duffing oscillator can improve the detection sensitivity and anti-interference capability. In this paper, combining Duffing oscillator with ZOCT, a new scheme of fault section determination is presented, with good sensitivity and reliability. The results of simulation and experiments proved this method is effective and feasible.
Relationship between the degree of polarization and stability of source wavelength in fiber optic sensors
Lishuang Feng, Yan Li, Hongjie Xu, et al.
In high precision fiber optical sensors, the instability of polarization states of light, especially the degree of polarization (DOP), becomes the main factor restricting the enhancement of the instrument performance. For the first time the relationship between DOP of input light and the mean wavelength of output light when light passes the waveguide polarizer was put forward in this paper. Based upon Muller matrix, the system mathematical model was established. Using the software of MATLAB, simulation and analysis was accomplished. The results indicate that spectrum instability of output light and DOP of input light are entirety correlative. The mean wavelength of output light increases nonlinearly with the increasing of DOP of input light. Experimental configuration is put up and experiments are done to verify the results by simulation.
Study of optimization and imaging of pie slice array for mm-wave synthetic aperture system
Yuntao He, Yuesong Jiang
Passive mm-wave synthetic aperture imaging system applies the interferometric principle to sample brightness temperature in the spatial domain and retrieve the image by inverse Fourier transformation. An optimization model for synthesis aperture array was set up from the theory of u-v coverage. Using that model, a ten-antenna array in a pie slice area was optimized at different pie slice radius angle by simulated annealing algorithm. These antennas were to rotate around the radius center by 10 times with each time π/10 to form full u-v coverage. In this paper, the non-instantaneous imaging theory of rotating u-v coverage synthesis aperture system is analyzed. A method called Gridding was adopted to deal the data in u-v plane so as to use IFFT. In the end the imaging algorithm is used to get PSF of synthesis aperture system with the optimized arrays by computer simulating. The PSF at different pie slice radius angle was compared and analyzed.
Application of miniature interferometers in nanomeasuring and positioning technology
Jinping Chen, Tong Guo, Xing Fu, et al.
In this article, a work on applying miniature interferometers in nano measuring and positioning system will be introduced. Several types of miniature interferometers, including corner-cube-retroreflector ones, plane-mirror-retroreflector ones and their derivations, will be described. Based on the single-beam plane-mirror interferometers, the triaxial metric system of a Nano Positioning and Measuring Machine (NPMM) is set up. In a working space of 25 mm x 25 mm x 5 mm, the system obeys the "Abbe Principle" to the maximum, having a resolution of 0.1 nm and an uncertainty of measurement of 5 nm - 10 nm.
Endoscopic optical coherence tomography system with rotating scan
Xiaodong Chen, Qiao Li, Wanhui Li, et al.
Optical coherence tomography (OCT) is an emerging cross-sectional imaging technology. Compared with other imaging methods, OCT has its unique features including ultrahigh resolution, non-invasion, non-touch and easily combined with fiber. OCT is sensitive enough to get cross-sectional image of bio-tissue(transparent and turbid) . In this paper, the principle of OCT is presented and the crucial parameters which influence the quality of image are discussed in theory. Based on the analysis of different method and medical endoscopic system's feature, a design which combines the spectral OCT(SOCT) technique and endoscopy is put forward. At the meantime, a novel OCT probe which uses advanced min-motor to drive reflecting prism is designed according to alimentary tract endoscopy's feature. Interference part, spectral receiving part, data acquisition and disposal part are built up. An experiment which uses multi-layered cover-glass as sample is done. The result verifies the feasibility of endoscopic optical coherence tomography system with rotating scan.
A new fiber Bragg grating accelerometer
Li Teng, Lishuang Feng, Heng Lin, et al.
A design method for a novel differential fiber Bragg grating (FBG) accelerometer is presented in this paper. The resonance frequency is increased via this sensing element design, which is combining the big beam and the two tiny beams. The differential double FBGs design increases the accelerometer sensitivity and resolves the temperature compensation. The mathematics model of the sensing element is established, the static and modal mechanics character is simulated by finite element method, the results indicate that the system sensitivity is 53.1pm/g and resonance frequency is 250Hz which is three times than that of the conventional cantilever-mass FBG accelerometer. The problem of being not able to increase the sensitivity and the resonance frequency simultaneously for the conventional FBG accelerometer has been resolved radically. Finally, the test system is set up, the testing data of the sensing element structure characteristic are acquired and analyzed.
A hybrid optical system for broadband imaging in guidance and control
Xiaofang Wu, Yuesong Jiang, Chunyan Shen, et al.
A binary optics method has been adopted to improve upon a conventional optical system in guidance and control, and a hybrid broadband imaging system that includes a binary surface is analyzed and evaluated by optical design software ZEMAX. The practical design shows that the introduction of binary optics can simplify the structure of the imaging system and reduce the size and weight of the broadband guidance and control system. Moreover, it can help to acquire images of radiation of different wavelengths from targets; hence it will result in improved overall performance of missiles in wars.
Design for spectrum-dividing system in multispectral guidance optical system
Chunyan Shen, Yuesong Jiang, Xiaofang Wu
Multi-spectral Guidance is most important in the development of modern Optical Guidance System. This paper advances a scheme of spectrum-dividing system used in the multi-spectral guidance optical system. The scheme introduces prismatic technology into the design of optical system of the Guidance System. Combining characters of optical thin-films and prisms and optimizing filmy parameters by Simulated annealing algorithm so that it can divide the multi-spectrum into available spectrums completely. Consequently, a miniature, lightweight spectrum-dividing construction, suitable for different wavelengths, has achieved. It satisfies the requirements of a multi-spectral optical guidance system. And the spectrum-dividing system designed in this paper can divide a wide spectrum ranged from 0.4 to 5.0μm into three spectra, which are visible, short-infrared and medium-wave infrared separately. Compared with the traditional guidance system, it can improve the detecting capability effectively.
Precision multi-point fiber optic temperature sensor
Li Li, Bo Liu, Yuanhong Yang
A time-division multi-point precision temperature sensor based polarization mode interference in polarization maintain fiber was proposed. The sensing principle was demonstrated and a practical mathematical model was obtained. With time division technology, the digital multi-points temperature sensor system was designed and realized. An experimental system was set with digital circuit based on micro-processor. The linearity technology and its precision were investigated. With the mathematical model, the linear output was obtained within -15°C~+55°C and this scheme was proved. The physical 0°C environment was formed with the mixer of ice and water and one hour sensor output in 0°C environment was recorded. Experimental result shows the resolution and stability of the temperature sensor can be better than 0.01°C.
A vision fusion treatment system based on ATtiny26L
Xiaoqing Zhang, Chunxi Zhang, Jiqiang Wang
Vision fusion treatment is an important and effective project to strabismus children. The vision fusion treatment system based on the principle for eyeballs to follow the moving visual survey pole is put forward first. In this system the original position of visual survey pole is about 35 centimeters far from patient's face before its moving to the middle position between the two eyeballs. The eyeballs of patient will follow the movement of the visual survey pole. When they can't follow, one or two eyeballs will turn to other position other than the visual survey pole. This displacement is recorded every time. A popular single chip microcomputer ATtiny26L is used in this system, which has a PWM output signal to control visual survey pole to move with continuously variable speed. The movement of visual survey pole accords to the modulating law of eyeballs to follow visual survey pole.
The study of dual camera 3D coordinate vision measurement system using a special probe
Shugui Liu, Kai Peng, Xuefei Zhang, et al.
Due to high precision and convenient operation, the vision coordinate measurement machine with one probe has become the research focus in visual industry. In general such a visual system can be setup conveniently with just one CCD camera and probe. However, the price of the system will surge up too high to accept while the top performance hardware, such as CCD camera, image captured card and etc, have to be applied in the system to obtain the high axis-oriented measurement precision. In this paper, a new dual CCD camera vision coordinate measurement system based on redundancy principle is proposed to achieve high precision by moderate price. Since two CCD cameras are placed with the angle of camera axis like about 90 degrees to build the system, two sub-systems can be built by each CCD camera and the probe. With the help of the probe the inner and outer parameters of camera are first calibrated, the system by use of redundancy technique is set up now. When axis-oriented error is eliminated within the two sub-systems, which is so large and always exits in the single camera system, the high precision measurement is obtained by the system. The result of experiment compared to that from CMM shows that the system proposed is more excellent in stableness and precision with the uncertainty beyond ±0.1 mm in xyz orient within the distance of 2m using two common CCD cameras.
Spatial 3-D nonlinear calibration technique for PSD
Lifeng Guo, Guoxiong Zhang, Qi Zheng, et al.
A 3-D nonlinear calibration technique for Position sensitive detector (PSD) in long distance laser collimating measurement is proposed. An automatic calibration system was developed to measure the nonlinearity of a 2-D PSD in 3-D space. It is mainly composed of a high accurate 2-D motorized translational stage, a high precision distance measuring device, and a computer-based data acquisition and control system. With the aid of the calibration system, the nonlinear characteristic of 2-D PSD is checked in a long collimating distance up to 78 meters. The calibration experiment was carried out for a series of distance, e.g. every 15 meters. The results showed that the nonlinearity of 2-D PSD is different evidently when the PSD element is at different distance from the laser head. One calculating method is defined to evaluate the nonlinear errors. The spatial 3-D mapping relationship between the actual displacements of the incident light and the coordinates of 2-D PSD outputs is established using a multilayer feedforward neural network.
Research on the fiber point-diffraction interferometer for spherical figure measurement
Lingfeng Chen, Liang Nie, Taogeng Zhou, et al.
The primary restriction on the precision of spherical figure measurement is the imperfectness of the reference spherical wavefront. Using the nearly perfect spherical wavefront diffracting from a single mode fiber as the reference, the accuracy of spherical figure measurement can be greatly improved. To get good contrast of interference fringe, the extraneous interference should be eliminated, and the intensity of the reference beam must match to the measuring beam at the same time. Using the short coherence length laser source can avoid most of the extraneous interference. The principles through stretching the resonant cavity length to shorten the coherence length are discussed; the effects are validated by constructing a Twymann-Green interferometer using the cavity length tunable YAG solid state laser. Calculations on light intensity show that only through controlling the attenuation of the measuring beam, can it match to the reference beam. Coating the fiber tips with semi-metallic film can substantially improve the contrast of the interference fringe. Comparing to the measurement results of ZYGO interferometer, the single interference pattern collected by our experimental fiber PDI apparatus is analyzed and the major error sources are also discussed.
VCSEL-based fiber optic link for avionics: implementation and performance analyses
Jieqin Shi, Chunxi Zhang, Jingyuan Duan, et al.
A Gb/s fiber optic link with built-in test capability (BIT) basing on vertical-cavity surface-emitting laser (VCSEL) sources for military avionics bus for next generation has been presented in this paper. To accurately predict link performance, statistical methods and Bit Error Rate (BER) measurements have been examined. The results show that the 1Gb/s fiber optic link meets the BER requirement and values for link margin can reach up to 13dB. Analysis shows that the suggested photonic network may provide high performance and low cost interconnections alternative for future military avionics.
Research of the coating resin performance of the polarization-maintaining fiber coil
Zhaokui Meng, Hongfeng Shao, Hongjie Xu, et al.
The coating resin performance of the Polarization-Maintaining fiber coil is an important fact to affect the performance of the FOG. It is one of some problems in the fact during the industrialization of the FOG. From the action and effect on the two important performance parameters such as temperature and vibration of the fiber ring and Fiber Optical Gyroscope (FOG). In allusion to the factual conditions of the FOG, all aspects of experiments are done and the experiment results are analyzed. The experiment and analysis results show that the facts to affect coating resin performance of the Polarization-Maintaining fiber coil is brought due to the unsuitable coating adhesive. The amount and uniformity of coating resin are the two main facts of the effect. In addition, the temperature performance of the resin and the remaining stress which are the facts to affect the coating resin performance of the Polarization-Maintaining fiber coil can not be ignored.
Artificial Intelligence, Network, and Fault Detection
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Research on compound learning algorithm of Bayesian networks structures
Xiao Liu, Haijun Li
Today, there are more mature and relative perfect means of how to learn structures or parameters from completed data and learn parameters of fixed structure from uncompleted data. But it is a more difficult thing that learning structures of Bayesian Networks from uncompleted data. A compound learning algorithm is proposed; it combines the EM algorithm, Monte Carlo sampling algorithm and evolution algorithm together, uses EM algorithm to learn parameters of networks in uncompleted data, then samples the best network, converts the uncompleted data to completed data, and then evolves the structure using evolution algorithm. This algorithm could get over the defect of EM algorithm that frequently gains local maximum. Because data processing is based on posterior networks structures, structures of Bayesian Networks is optimizing and optimizing with evolution computing, the reliability of complementary data is higher. Learning rate is high and performance of this algorithm is good.
A new autonomous celestial navigation method for Mars probe
Tingting Song, Xiaolin Ning, Wenbo Yu
This paper focuses on a new celestial navigation method for Mars probe on the transferring orbit. The dynamical model is established first. Then the celestial measurement is obtained by two ways, one is to choose the angles between the line of sight vectors from the Sun, the Earth and the Mars to the probe, the other kind of celestial measurement is the measurement of angles between the Sun, the Earth, the Mars and three stars. Autonomous orbit navigation is obtained by Unscented Kalman Filter (UKF). The simulation illustrates that the latter way is much better than the first one at the precision.
Autogenous shrinkage prediction on high-performance concrete of fly ash based on BP neural network
Baomin Wang, Wenping Zhang, Lijiu Wang
The article adopts test data of neural network for autogenous shrinkage to train and predict on the data which doesn't join training. The article's prediction is on the basis of common medium sand, 5-31.5mm limestone rubble, second class fly-ash, P.O42.5 silicate cement, considering factors include five ones such as ratio of water and cement, sand rate, content of cement, content of fly ash, etc.By adjusting various parameters of neural network structure, it obtains three optimized results of neural network simulation. The error between concrete autogtenous shrinkage value of neural network prediction and trial value is within 3%, which can meet requirement of the concrete engineering.
Microturbine control based on fuzzy neural network
Shijie Yan, Chunyuan Bian, Zhiqiang Wang
As microturbine generator (MTG) is a clean, efficient, low cost and reliable energy supply system. From outside characteristics of MTG, it is multi-variable, time-varying and coupling system, so it is difficult to be identified on-line and conventional control law adopted before cannot achieve desirable result. A novel fuzzy-neural networks (FNN) control algorithm was proposed in combining with the conventional PID control. In the paper, IF-THEN rules for tuning were applied by a first-order Sugeno fuzzy model with seven fuzzy rules and the membership function was given as the continuous GAUSSIAN function. Some sample data were utilized to train FNN. Through adjusting shape of membership function and weight continually, objective of auto-tuning fuzzy-rules can be achieved. The FNN algorithm had been applied to "100kW Microturbine control and power converter system". The results of simulation and experiment are shown that the algorithm can work very well.
Research on simulation methods of evaluation for diagnostic Bayesian networks
Haijun Li, Lin Li, Yongqing Yu
Bayesian Networks that based on probability inference is proposed to solve problems of uncertainty and imperfection. It has more advantages to solve faults caused by uncertainty and relevancy of complex devices. Diagnostic models of Bayesian Networks must be evaluated roundly before used for diagnosis. The usual way to evaluate diagnostic models is using standard cases to test the model, but the cases are limited and the quality of these cases depend on their source, and these cases could not include all instances. Based on sample means of Monte Carlo, an algorithm of evaluation for diagnostic models is proposed this article; this algorithm does not need special diagnostic cases. Faults injecting algorithm with equal probability of every components are adopted, test cases are produced by this algorithm of system itself, and course of faults propagation is simulated by this algorithm of system too. This algorithm could test diagnostic models roundly, and make overall evaluation of diagnostic models.
Research on information fusion for engineering system integrated health management
Zhanbao Gao, Xingshan Li, Cong Sun, et al.
Integrated Health Management technology is the emerging paradigm in system supervision and maintenance area, and it is the key to achieving true condition-based maintenance. But this task is complicated by the extremely large amount of the data available, the existence of uncertainties, and interactive engineering system operational conditions. Therefore, it is reasonable to research the health information fusion technology to achieve better performance and a higher level of autonomy for IHM system. This paper analyses the requirements of the information fusion in an IHM system, describes the fusion application areas, proposes the Health Sensing Unit (HSU) concept, and designs the distributed hierarchical fusion architecture. Using the confidence distance matrix as the measure of HSU's performance, this paper proposes a fusion algorithm to fuse multiple HSUs' output, and figure out the system health index according to the maximum likelihood principle. The simulation result yields conclusive evidence that fusion can be very valuable in the IHM technology for the system supervision and maintenance.
Multi-concurrent fault diagnosis method for turbo-generator set based on wavelet fuzzy network
Hua Liu, Yuguo Wang, Baoshe Liang, et al.
To improve the limitation of applying traditional fault diagnosis method to the diagnosis of multi-concurrent vibrant faults of turbo-generator sets, a new diagnosis approach combining the wavelet transform with fuzzy theory is proposed. A novel method based on the statistic rule is brought forward to determine the threshold of each order of wavelet space and the decomposition level adaptively, increasing the signal-noise-ratio (SNR). The effective eigenvectors are acquired by binary discrete wavelet transform and the fault modes are classified by fuzzy diagnosis equation based on correlation matrix. The fault diagnosis model of turbo-generator set is established and the improved least squares algorithm (LSA) is used to fulfill the network structure and the robustness of fault diagnosis equation is discussed. By means of choosing enough samples to train the fault diagnosis equation and the information representing the faults is input into the trained diagnosis equation, and according to the output result the type of fault an be determined. Actual applications show that the proposed method can effectively diagnose multi-concurrent fault for stator temperature fluctuation and rotor vibration and the diagnosis result is correct.
Rule extraction of fault diagnosis based on a modified artificial immune algorithm
Xiaoli Hao, Keming Xie
When employed in fault diagnosis, rough set can realize attribution reduction. But it can not discrete attribution and reduct attribution simultaneously, therefore we can not say that it can automatically extract rules. To solve the problem, a new rule extraction method based on developed artificial immune algorithm is firstly proposed in the paper. At first, a new method of encoding is produced which can make the process of discretion and reduction unify. Secondly, a new definition of concentration of antibodies not only compare individuals in structure and space, but also in fitness value. Thirdly, the algorithm provide dissimilation operator and similar-taxis operator, which replace choice, expansion and mutation in traditional artificial immune algorithm. All these developments not only maintain diversity of the antibody population, but also converge faster. Finally, we apply the algorithm to fault diagnose of heat recoup system in steam turbine. Tests proved that the algorithm is feasible, and the diagnose rules acquired by the algorithm have higher accuracy rate.
Intelligent classifier for dynamic fault patterns based on hidden Markov model
Bo Xu, Yuguang Feng, Jinsong Yu
It's difficult to build precise mathematical models for complex engineering systems because of the complexity of the structure and dynamics characteristics. Intelligent fault diagnosis introduces artificial intelligence and works in a different way without building the analytical mathematical model of a diagnostic object, so it's a practical approach to solve diagnostic problems of complex systems. This paper presents an intelligent fault diagnosis method, an integrated fault-pattern classifier based on Hidden Markov Model (HMM). This classifier consists of dynamic time warping (DTW) algorithm, self-organizing feature mapping (SOFM) network and Hidden Markov Model. First, after dynamic observation vector in measuring space is processed by DTW, the error vector including the fault feature of being tested system is obtained. Then a SOFM network is used as a feature extractor and vector quantization processor. Finally, fault diagnosis is realized by fault patterns classifying with the Hidden Markov Model classifier. The importing of dynamic time warping solves the problem of feature extracting from dynamic process vectors of complex system such as aeroengine, and makes it come true to diagnose complex system by utilizing dynamic process information. Simulating experiments show that the diagnosis model is easy to extend, and the fault pattern classifier is efficient and is convenient to the detecting and diagnosing of new faults.
Neural adaptive Kalman filter's application in MIMU/GPS/MMC integrated navigation systems
Juanjuan Cao, Jiancheng Fang, Wei Sheng
This paper presents a novel method for sensors data fusion based on Neural Adaptive kalman filter. The method is applied in fusing data from MIMU, GPS and Micro magnetism compass integrated navigation system for Micro autonomous Uninhibited Aerial Vehicles (UAV).The noise covariance of kalman filter is modified "online" by the Neural Adaptive Controller in order to modulate kalman filter to be optimal and to improve the positioning, velocity and attitude angle accuracy of the integrated navigation system. To demonstrate the effectiveness and accuracy of this method, an example is outlined. By simulation in the MIMU/GPS/MMC integrated navigation system, it is proved that the Neural Adaptive Kalman Filter has better accuracy than the regular Extended Kalman Filter.
Dynamic sensing optimization strategy for mobile nodes deployment in wireless sensor networks
Sheng Wang, Xue Wang, Junjie Ma
Sensor nodes deployment problem is one of the fundamental issues in wireless sensor networks (WSNs) which should consider a tradeoff among several metrics, such as coverage area, reliability, accuracy, lifetime etc. The mobile sensor nodes which can relocate themselves can be used to optimize the nodes deployment under various kinds of situations. Because coverage area is hard to be calculated by analytical method, an areas division method is introduced to evaluate the coverage area metric for simplifying calculation. Then we introduce a practically feasible combined metric which refers to coverage area, reliability, accuracy and lifetime, which uses areas division, detecting reliability, Mahalanobis distance and energy entropy as metric functions. Here, nodes deployment is considered as an optimization problem. Particle swarm optimization (PSO) algorithm, which has a series of advantages, such as, high-speed regional convergence, efficient global searching ability, and so on, is suitable for solving multi-dimension function optimization in continuous space. So we adopt PSO for nodes deployment optimization where the combined metric is considered as fitness function. Because the combined metric is multiform and changeable in PSO, we can adopt different combined metrics for different applications, while other strategies just consider the coverage area in nodes deployment. The experimental results verify that the PSO based mobile nodes deployment strategy has good performance in quickness, which can improve the capabilities of WSNs and dynamically adjust the deployment according to the changes of situation, especially when some areas need multiple-node-measurement.
The study of human bodies' impedance networks in testing leakage currents of electrical equipments
Zhaohui Zhang, Xiaofei Wang
In the testing of electrical equipments' leakage currents, impedance networks of human bodies are used to simulate the current's effect on human bodies, and they are key to the preciseness of the testing result. This paper analyses and calculates three human bodies' impedance networks of measuring electric burn current, perception or reaction current, let-go current in IEC60990, by using Matlab, compares the research result of current effect thresholds' change with sine wave's frequency published in IEC479-2, and amends parameters of measuring networks. It also analyses the change of perception or reaction current with waveform by Multisim.
Design of fault diagnosis system for inertial navigation system based on virtual technology
Baiqing Hu, Boxiong Wang, An Li, et al.
With regard to the complex structure of the inertial navigation system and the low rate of fault detection with BITE (built-in test equipment), a fault diagnosis system for INS based on virtual technologies (virtual instrument and virtual equipment) is proposed in this paper. The hardware of the system is a PXI computer with highly stable performance and strong extensibility. In addition to the basic functions of digital multimeter, oscilloscope and cymometer, it can also measure the attitude of the ship in real-time, connect and control the measurement instruments with digital interface. The software is designed with the languages of Measurement Studio for VB, JAVA, and CULT3D. Using the extensively applied fault-tree reasoning and fault cases makes fault diagnosis. To suit the system to the diagnosis for various navigation electronic equipments, the modular design concept is adopted for the software programming. Knowledge of the expert system is digitally processed and the parameters of the system's interface and the expert diagnosis knowledge are stored in the database. The application shows that system is stable in operation, easy to use, quick and accurate in fault diagnosis.
Early detection for short-circuit fault in low-voltage systems based on fractal exponent wavelet analysis
Shanlin Kang, Bingjun Wang, Yuzhe Kang
By combining wavelet transform (WT ) with fractal theory, a novel approach is put forward to detect early short-circuit fault. The application of signal denoising based on the statistic rule is brought forward to determine the threshold of each order of wavelet space, and an effective method is proposed to determine the decomposition adaptively, increasing the signal-noise-ratio (SNR). In a view of the inter relationship of wavelet transform and fractal theory, the whole and local fractal exponents obtained from WT coefficients as features are presented for extracting fault signals. The effectiveness of the new algorithm used to extract the characteristic signal is described, which can be realized by the value of the fractal dimensions of those types of short-circuit fault. In accordance with the threshold value of each type of short-circuit fault in each frequency band, the correlation between the type of short-circuit and the fractal dimensions can be figured to perform extraction. This model incorporates the advantages of morphological filter and multi-scale WT to extract the feature of faults meanwhile restraining various noises. Besides, it can be implemented in real time using the available hardware. The effectiveness of this model was verified with the simulation results.
Expert system for web based collaborative CAE
Liang Hou, Zusheng Lin
An expert system for web based collaborative CAE was developed based on knowledge engineering, relational database and commercial FEA (Finite element analysis) software. The architecture of the system was illustrated. In this system, the experts' experiences, theories and typical examples and other related knowledge, which will be used in the stage of pre-process in FEA, were categorized into analysis process and object knowledge. Then, the integrated knowledge model based on object-oriented method and rule based method was described. The integrated reasoning process based on CBR (case based reasoning) and rule based reasoning was presented. Finally, the analysis process of this expert system in web based CAE application was illustrated, and an analysis example of a machine tool's column was illustrated to prove the validity of the system.
Research and design of an expert system of trouble diagnosis for the diesel engine in the railroad
Qizhong Cai, Zhixin Chen, Yingying Wei, et al.
This paper presents an expert system of trouble diagnosis for the diesel engine in the railroad. It was expounded that the essential content of knowledge base for trouble diagnosis in the system. And it was researched that how to build reasoning system by logic theory method, accordingly the logic theory mechanism was designed based on the logic. Consequently the efficiency of diagnosis was improved and worked speedily and properly. The man-machine interface was designed well by using Visual C++ so that trouble diagnosis the expert system is usable for the diesel engine in the worked location. The system is so opened and extended that maintenance man fulfills the conversion form the experiential knowledge in the practice to the identifiable symbol in the system without the helping of technology engineering. Further more the veracity and of diagnosis would be improved in the process of trouble diagnosis for the diesel engine.
A review of fault prognostics in condition based maintenance
Lei Zhang, Xingshan Li, Jinsong Yu
The main idea of condition based maintenance (CBM) is to monitor the health of critical machine components and system almost continuously during operation and maintenance actions based on the assessed condition. If done correctly, CBM has the benefits such as reducing catastrophic failures, minimizing maintenance and logistical cost, maximizing system security and availability and improving platform reliability. A CBM system usually has four functional modules: feature extraction, diagnostics, prognostics and decision support. Among them, fault prognostics is the most important enabling technology. It is the most challenging research area which is so called crystal ball of CBM. But it has the potential to be the most beneficial one. A review of recent progress of fault prognostics is conducted with the emphasis placed on its algorithmic approaches. These approaches generally fall into four main categories, namely experience-based approaches, model-based approaches, knowledge-based approaches and data-driven approaches. Based on the analysis of some typical examples on each prognostic approaches, the advantages and disadvantages of these approaches are further discussed. Finally, the future challenges concerned with fault prognostics are also presented.
A new engine fault diagnosis method based on spectrometric oil analysis
Jingwei Gao, Peilin Zhang, Zhengjun Wang, et al.
According to statistics, wear fault is about sixty percent to eighty percent of all the machinery faults. Spectrometric oil analysis is an important condition monitoring and fault diagnosis technique for machinery maintenance. In practice, there are two existing fault diagnosis model of the engine based on spectrometric oil analysis, namely concentration model and gradient model. However, the two above models have their respective disadvantages in condition monitoring and fault diagnosis of the engine. In this paper, a new condition monitoring and fault diagnosis method, proportional model is described. Proportional model use the correlation among the elements in the lubricating oil to detect wear condition and occurring faults in the engine. Then the limit value of proportional model is established by analyzing a lot of spectrum data. In order to validate the availability and effect of proportional model, this paper apply proportional model to an engine and sampling the lubricating oil every 5 hours. Through analyzing the lubricating oil by spectrometer, we find that proportional model could find the abnormal wear information in spectrum data, give more accurate result of wear condition and give the fault form in the engine. The results from this paper prove that this method based on proportional model is applicable and available in condition monitoring and fault diagnosis of the engine.
Application of dynamic recurrent neural networks in nonlinear system identification
Yun Du, Xueli Wu, Huiqin Sun, et al.
An adaptive identification method of simple dynamic recurrent neural network (SRNN) for nonlinear dynamic systems is presented in this paper. This method based on the theory that by using the inner-states feed-back of dynamic network to describe the nonlinear kinetic characteristics of system can reflect the dynamic characteristics more directly, deduces the recursive prediction error (RPE) learning algorithm of SRNN, and improves the algorithm by studying topological structure on recursion layer without the weight values. The simulation results indicate that this kind of neural network can be used in real-time control, due to its less weight values, simpler learning algorithm, higher identification speed, and higher precision of model. It solves the problems of intricate in training algorithm and slow rate in convergence caused by the complicate topological structure in usual dynamic recurrent neural network.
Dynamic hierarchical committee for mulitple agent decision in wireless sensor networks
Xue Wang, Sheng Wang, Aiguo Jiang
Decision methods for information processing affect significantly the efficiency and accuracy of networked sensing in wireless sensor networks. Mobile agent technology supplies an efficient cooperation mechanism, which can compensate the poor capability of single node. This paper proposes a dynamic hierarchical committee for multiple agent decision, which is a two-level structure: in the lower level, several sub-committees, concluding a local decision respectively, are dynamically organized by the energy-efficient optimization of adapted genetic algorithm; local decisions of sub-committees are nonlinearly combined in the upper level. The performance of dynamic hierarchical committee is verified through simulation and practical defect location of printed circuit board. The results show the proposed method can remarkably decrease the energy consumption with sacrifice of real-time. The confidence and accuracy of decision is more precise than centralized non-committee method.
Low-energy routing based on ant colony algorithm genetic algorithm in wireless sensor networks
Shi Zhang, Qiannan Lu, Zhe Zhang, et al.
While designing the routing protocol in wireless sensor networks (WSN), one of the key problems is to keep the energy-load balance over the network for prolonging its lifetime. In this paper, we propose a low-energy clustering WSN routing protocol based on Ant Colony Algorithm Genetic Algorithm (ACAGA). The protocol divides the network into several clusters and selects cluster heads according to the relative locations and the residual energy status of nodes. While keeping the energy-load balance over the whole network, it accomplishes a low-energy routing and prolongs the whole network's lifetime by using the distributed computation and global route optimization capabilities of ACAGA.
Design and analysis on the dynamics of ICPF actuated tortoise-like flexible micro-robot
Lin Nie, Desheng Li, Shuxiang Guo
In the paper, we present a novel tortoise-like flexible micro-robot with four legs which can crawl and swim underwater. These legs are actuated by ICPF (Ionic Conducting Polymer Film) which is a kind of smart film and has the characteristics of flexibility, good response and being driven by a low voltage. For improving the robot's reliability and feasibility, we establish the micro-robot's dynamic model by applying Pseudo-Rigid-Body-Dynamic-Model (PRBDM). The model is established by considering the dynamic effect of the robot, which is based on statics and kinematics. Then, the frequency analysis of a micro-robot based on PRBDM is investigated. Based on the PRBDM, the relation between the robot's structure parameters and its natural frequency is theoretically derived and a numerical computation of the robot is performed.
Research on features of faulting redundant actuation manipulator
Caixia Yan, Zhen Lu
Fault tolerance of robot was highly demanded in hazard working circumstances. And, actuator fault is a common type of system failure. This paper researches some basic issues of 2-DOF planar redundant actuation parallel system and faulting robot. At the beginning, the Jacobian matrix resolving problem of redundant actuation parallel robot is introduced, and the Jacobian matrix actuator fails is deduced. Furthermore, the forward and inverse position solution methods for both redundant actuation parallel manipulator and system with faulting actuator are presented. With detailed example, the validation of position solution method is proved. Moreover, the workspace analysis method of the redundant parallel manipulator pre and post faulting is addressed. Also, the resolving diagram is included. Finally, based on virtual work principle, a new way to reallocate actuation force and faulting compensation is introduced.
Fault diagnosis approach based on module fuzzy subsystems
Hong Lv, Haiwen Yuan, Haibin Yuan
Module fuzzy subsystems approach is introduced to solve Electrical Apparatus Control System (EACS) fault diagnosis problem in this paper. First, the input vectors are classified into several classifications using Radial Basis Function (RBF) neural network according to the faults occurring part. Then, a module subsystem is designed separately based on Fuzzy Neural Network (FNN) with exponential function fuzzy pattern matching. Finally, SF6 breaker faults diagnosis application is employed to validate the effectiveness of the proposed method. Simulation result shows that the diagnosis approach for the structure of module fuzzy subsystems can solute the problem of rules quick increasing with the input vector increasing, and the algorithm of fuzzy pattern matching with exponential function can improve the diagnosis precision.
A fault diagnosis method based on parametric estimation in hydraulic servo system
Hongmei Liu, Pingchao Ouyang, Shaoping Wang
Due to the fault occurrence could commonly be considered as results of the physical parameters variation of the system and this variation usually is embodied by model coefficients variation of the system, faults can be detected and diagnosed according to the model parameter variation of the system. In this paper, a parametric estimation method, which is extended to extract features existing in input and output data of the monitored system, is employed to realize the FDD for a hydraulic servo system. An Auto-Regressive model with exogenous input (ARX) is selected to approximate the dynamic behavior of the system. Then according to the feature vector constructed by the coefficient of ARX model, faults are classified in feature space using RBF neural network to realize the fault localization. Experiments and simulations results indicate that the proposed method is effective in fault diagnosis for hydraulic servo system.
Home medical monitoring network based on embedded technology
Guozhong Liu, Wenyi Deng, Bixi Yan, et al.
Remote medical monitoring network for long-term monitoring of physiological variables would be helpful for recovery of patients as people are monitored at more comfortable conditions. Furthermore, long-term monitoring would be beneficial to investigate slowly developing deterioration in wellness status of a subject and provide medical treatment as soon as possible. The home monitor runs on an embedded microcomputer Rabbit3000 and interfaces with different medical monitoring module through serial ports. The network based on asymmetric digital subscriber line (ADSL) or local area network (LAN) is established and a client - server model, each embedded home medical monitor is client and the monitoring center is the server, is applied to the system design. The client is able to provide its information to the server when client's request of connection to the server is permitted. The monitoring center focuses on the management of the communications, the acquisition of medical data, and the visualization and analysis of the data, etc. Diagnosing model of sleep apnea syndrome is built basing on ECG, heart rate, respiration wave, blood pressure, oxygen saturation, air temperature of mouth cavity or nasal cavity, so sleep status can be analyzed by physiological data acquired as people in sleep. Remote medical monitoring network based on embedded micro Internetworking technology have advantages of lower price, convenience and feasibility, which have been tested by the prototype.
An adaptive federated filter algorithm based on improved GA and its application
Wei Quan, Jiancheng Fang
Pointing to some complex systems, general federated filters can not be suit for rather large changes of system parameters, and various inertial devices all exists the defect of error accumulating as time, which cause inaccuracy of model and bad performance of filters. So, in order to meet the requirements of accurate model building, it is very necessary to adaptively adjust for the noise model parameters of integrated navigation system. Based on SINS/CNS/GPS integrated navigation system model for long flight-time unmanned plane, pointed to low precision of model & filtering and stability & practicability of filtering algorithms, an adaptive federated filter algorithm based on improved GA was established in this paper. This algorithm avoids the premature convergence problem of general GA by improving the fitness function, takes advantage of decimal-coded to improve both the speed and the accuracy of calculating, builds the adaptive federated filter model based on improved GA through analyzing the model parameters of reference-system and local-filters. In the end, the semi-physical simulation is done by using this method. The experimental results show that as compared with adaptive federated filter algorithm, this filter not only increase the navigation system's accuracy and reliability greatly, but also owns quick rapidity of convergence. It has high merits of project application.
Application of artificial neural networks in oil and gas multiphase metering
Huimin Yang, Yuxing Li, Fuxian Zhou, et al.
In order to study the law of multiphase flow in pipeline and solve the on-line multiphase metering problem without separation of gas and liquid, a new type of multiphase flowmeter was developed and a series of water-gas two phase flows experiments in horizontal pipeline were carried out. And Artificial Neural Networks was used to process data after the experiments. The results show that Artificial Neural Networks could be used to simulate the relationship of the variables that were affected by many uncertain factors very well. And the relative error of liquid phase is less than 10% as well as the relative error of gaseous phase is less than 20%.
Research on the application of ensemble neural network in integrated navigation system
Fan Xu, Jiancheng Fang
The conventional Kalman filter assumes that the system model and the observation model is linearity. Also the noise in system and observation model is white noise. However the practical environment is very complex. When we use Kalman filter to estimate, we can not got the transcendent information. The paper considers the characteristic of aircraft, research the structure and scheme of INS/CNS/GPS integrated navigation system. The error model of integrated navigation system has been set up. The status of navigation system has been estimated with Kalman filter, and the simulation calculation has been progressed. The paper presents a method, which use neural network ensembles to deal with the Kalman filter. This method improves the generalization and stabilization ability. The simulation shows that the arithmetic has high precision.
A novel atmospheric turbulence-degraded image restoration algorithm based on support vector regression
Chun-sheng Liu, Ming Li
A novel method based on support vector regression is presented for atmospheric turbulence-degraded image restoration. Firstly, an operation with a sliding window is employed to the images to analyze the correlation between pixels of clear image and 8 neighbors of corresponding pixels of degraded image. After feature selection, we get training samples. Secondly, an appropriate kernel function is employed to map the training samples into a higher space. Through linear learning machine in kernel feature space, we get non-linear function. Then the relationship between clear images and degraded images is constructed via regression analysis of the training samples by a support vector machine. Thus the model for turbulence-degraded image restoration is constructed here. Finally, the degraded images to be tested are restored by this model. The experimental results show that the proposed method has lower NMSE and higher PSNR and runs faster than classical image restoration methods such as Wiener Filter, Iterative Blind Deconvolution and etc.
Power distribution system diagnosis with uncertainty information based on rough sets and clouds model
Qiuye Sun, Huaguang Zhang
During the distribution system fault period, usually the explosive growth signals including fuzziness and randomness are too redundant to make right decision for the dispatcher. The volume of data with a few uncertainties overwhelms classic information systems in the distribution control center and exacerbates the existing knowledge acquisition process of expert systems. So intelligent methods must be developed to aid users in maintaining and using this abundance of information effectively. An important issue in distribution fault diagnosis system (DFDS) is to allow the discovered knowledge to be as close as possible to natural languages to satisfy user needs with tractability, and to offer DFDS robustness. At this junction, the paper describes a systematic approach for detecting superfluous data. The approach therefore could offer user both the opportunity to learn about the data and to validate the extracted knowledge. It is considered as a "white box" rather than a "black box" like in the case of neural network. The cloud theory is introduced and the mathematical description of cloud has effectively integrated the fuzziness and randomness of linguistic terms in a unified way. Based on it, a method of knowledge representation in DFDS is developed which bridges the gap between quantitative knowledge and qualitative knowledge. In relation to classical rough set, the cloud-rough method can deal with the uncertainty of the attribute and make a soft discretization for continuous ones (such as the current and the voltage). A novel approach, including discretization, attribute reduction, rule reliability computation and equipment reliability computation, is presented. The data redundancy is greatly reduced based on an integrated use of cloud theory and rough set theory. Illustrated with a power distribution DFDS shows the effectiveness and practicality of the proposed approach.
Double any-position alignment without rotatable device for SINS
Baiqi Liu, Jiancheng Fang
The effect of gyro drift and accelerometer bias can be eliminated through Double-position alignment, which leads to a high precise initial alignment. However, the special rotatable device is indispensable to rotate SINS with respect to heading axis for the traditional double-position alignment witch is very inconvenient for many applications. A double any-position alignment without rotatable device for SINS is proposed in this paper, in which the SINS just need to be rotated from first position to any-position with respect to any axis by anyway. The experiment research is carried out, and the result indicated that the method determine the initial attitude of SINS and gyro drift precisely in relative short time.
Real-time communication research of control networks
Ming Li
With the networked development of control systems, control networks come into being. Control networks connect every component in networked control systems (NCS) and are the key of NCS, but they make the problems in control systems involving in control theory and communication networks. The real time of control networks determines the one of NCSs to some extent, so it is emphatically researched in this paper. Some wired and wireless control networks are discussed. Then, the data transmission procedure in control networks is analyzed, as well as the network-induced delay produced by exchanging data among the network nodes and the methods on how to improve the real time of control networks. Finally, a type of three-layer distributed database system is proposed, as well as a type of monitor & control layer real-time database structure, of which the design and implementation is discussed in detail. The distributed database system can optimize the data storage architecture of NCSs, lighten the network load and reduce the network congestion, so it has good effects on improving the real time of control networks.
Research on SVMs of small samples on rotary machine multiclass fault recognition
Xiaojun Gu, Shixi Yang, Suxiang Qian, et al.
The current development's major bottleneck of fault pattern recognition is the absence of fault samples, and not only the methodology itself. Most methods of mechanical fault recognition depend on the large samples of the statistical properties (such as neural network). When training limited samples, it is difficult to guarantee getting a better classification. In response to the lack of rotary mechanical diagnostic samples, this paper takes the advantages of Support Vector Machines (SVMs) in small sample classification for studying its application in small number of samples for rotary machine fault pattern recognition. For rotary machine's multi-class fault problem, we introduce three methods based on binary classifications: "one-against-all", "one-against-one", and "directed acyclic graph" SVM (DAGSVM) and then compare their performance in fault recognition. The experiments indicate that the SVMs has high adaptability for rotary machine fault diagnosis in the case of smaller number of samples and the "one-against-one" and DAG methods are more suitable for rotary machine fault diagnosis than the other.
A new handhold device with ID card identification
Wenrui Ding, Meihong Li, Jianwei Liu, et al.
With the application of 2nd generation ID card in China, it is imperative to research and develop a kind of device used to identify and verify the ID card. In this paper, we propose an original solution to implement above functions. Based on GPRS (General Package Radio Services), GPS (Global Position System) and IC (Integrated Circuit) Card technology, this solution fits the demands of the application. The state machine method is adopted to implement the software design. A practical and useful encryption algorithm is used, which meets the safety of this application completely. Our developed sample machines are tested and used. The results show that this solution is feasible and practical. In addition, the independence of the function and structure make sure that it is easier to maintain and upgrade the system according to the viewpoint of software engineering.