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- Front Matter: Volume 8321
- Seventh International Symposium on Precision Engineering Measurements and Instrumentation
Front Matter: Volume 8321
Front Matter: Volume 8321
Show abstract
This PDF file contains the front matter associated with SPIE
Proceedings Volume 8321, including the Title Page, Copyright
information, Table of Contents, and the Conference Committee listing.
Seventh International Symposium on Precision Engineering Measurements and Instrumentation
2D temperature field measurement in a direct-injection engine using LIF technology
Show abstract
A new multi-spectral detection strategy for temperature laser- induced- fluorescence (LIF) 2-D
imaging measurements is reported for high pressure flames in high-speed diesel engine. Schematic of the
experimental set-up is outlined and the experimental data on the diesel engine is summarized. Experiment injection
system is a third generation Bosch high-pressure common rail featuring a maximum pressure of 160MPa. The
injector is equipped with a six-hole nozzle, where each hole has a diameter of 0.124 mm. and slightly offset to the
center of the cylinder axis to allow a better cooling of the narrow bridge between the exhaust valves. The
measurement system includes a blower, which supplied the intake flow rate, and a prototype single-valve direct
injection diesel engine head modified to lay down the swirled-type injector. 14-bit digital CCD cameras are
employed to achieve a greater level of accuracy in comparison to the results of previous measurements. The
temperature field spatial distributions in the cylinder for different crank angle degrees are carried out in a single
direct-injection diesel engine.
The measurements of water flow rates in the straight microchannel based on the scanning micro-PIV technique
Show abstract
Measurement of the water flow rate in microchannel has been one of the hottest points in the applications of microfluidics, medical, biological, chemical analyses and so on. In this study, the scanning microscale particle image velocimetry (scanning micro-PIV) technique is used for the measurements of water flow rates in a straight microchannel of 200μm width and 60μm depth under the standard flow rates ranging from 2.481μL/min to 8.269μL/min. The main effort of this measurement technique is to obtain three-dimensional velocity distribution on the cross sections of microchannel by measuring velocities of the different fluid layers along the out-of-plane direction in the microchannel, so the water flow rates can be evaluated from the discrete surface integral of velocities on the cross section. At the same time, the three-dimensional velocity fields in the measured microchannel are simulated numerically using the FLUENT software in order to verify the velocity accuracy of measurement results. The results show that the experimental values of flow rates are well consistent to the standard flow rates input by the syringe pump and the compared results between numerical simulation and experiment are consistent fundamentally. This study indicates that the micro-flow rate evaluated from three-dimensional velocity by the scanning micro-PIV technique is a promising method for the micro-flow rate research.
The modeling of hemispherical resonator gyro and its space applications
Xu Wang,
Wenqi Wu,
Bing Lou,
et al.
Show abstract
The hemispherical resonator gyroscope (HRG) is a new vibration gyro, which first appeared in the 1960s. It has a feature
of high accuracy, long life span, no wear-out and great reliability. With its excellent performances, the HRG can be used
for spacecraft and satellite stabilization, precision pointing, aircraft navigation, strategic accuracy systems, oil borehole
exploration and planetary exploration.
Compared with traditional mechanical gyro and optical gyro, HRG has no rotators or movement parts. The resonator of
HRG is made from quartz with low damping and stable temperature. The resonator Q factor exceeds 5,000,000 and it is
placed under vacuum cap with residual pressure about 1×10−6 atm. The principium of HRG sensing the rotation relies on
a transverse stress wave in the solid resonator. The stable material character of resonator and simple structure make the
gyro high reliability, long lifetime, anti-radiation, anti-shock and high accuracy.
Two working modes of the HRG which is the whole angle mode and force to rebalance mode are respectively analyzed,
besides, the control loops applied in the gyro are illuminated in the paper. The basic kinetic model of the HRG is
investigated in the paper, from which the principle and exhibition of the error existing in the device could be obtained
clearly. At last, the HRG space applications are displayed and the result of the 100% mission success has demonstrated it
is the best candidate for critical and high value missions.
Design of the system of three-point target automatic orientation
Show abstract
To realize target automatic orientation, we establish the system of target automatic orientation. This system takes use of the
method of three-point-orientation, and analyses the method’s error. Base on the model of earth ellipse reference space target
orientation, this method use the position information of plane at different time and the distance of the target between the
aircraft to establish the math model of the method of three-point-orientation. At the same time, we get the target’s position
information through the exact math resolve. At last, we analyses the method’s error. The result shows the system using the
method of three-point-orientation has higher orientation precision. Latitude error can reach 0.00021degree, longitude error
can reach 0.00041 degree and altitude error can reach 15 meters. In practice flying, latitude error is 0.0004degree, longitude
error is 0.0008degree, altitude error is 20m.
Measurement error analysis of taxi meter
Show abstract
The error test of the taximeter is divided into two aspects: (1) the test about time error of the taximeter (2) distance test
about the usage error of the machine. The paper first gives the working principle of the meter and the principle of error
verification device. Based on JJG517 - 2009 "Taximeter Verification Regulation ", the paper focuses on analyzing the
machine error and test error of taxi meter. And the detect methods of time error and distance error are discussed as well.
In the same conditions, standard uncertainty components (Class A) are evaluated, while in different conditions, standard
uncertainty components (Class B) are also evaluated and measured repeatedly. By the comparison and analysis of the
results, the meter accords with JJG517-2009, "Taximeter Verification Regulation ", thereby it improves the accuracy and
efficiency largely. In actual situation, the meter not only makes up the lack of accuracy, but also makes sure the deal
between drivers and passengers fair. Absolutely it enriches the value of the taxi as a way of transportation.
Compatibility design for time grating interface based on forecasting method
Show abstract
Time grating is a novel displacement sensor which employs time to measure space. A new predictive method for
predicting the dynamic angular displacement of CNC rotary table is presented with time series. In addition, feedback
interface for rotary transformer is designed to update data speed for time grating in the measurement process. Experiment
results prove that forecast error for acceleration range from -0.00026″/ms2 to 0.00028″/ms2, and forecast angular
displacement error is within ±2″.
Weight function theory of dynamic accuracy loss
Show abstract
This paper carries out the research of the weights of the dynamic accuracy loss and weight functions. It uses the theory
of grey correlation analysis to obtain the weight functions of accuracy loss of each main structural unit. From the
magnitude of each weight, it can get the accuracy loss of the whole system from the accuracy loss of each structural unit.
Then, it uses this theory to analyze the accuracy loss of a practical measurement system, and obtains the weights of
accuracy loss of each structural unit. The theory of weight function of accuracy loss makes a foundation for further
design of equal accuracy measurement systems.
Suppression of radiated emission in fiscal taxi meter
Show abstract
This paper is based upon National Standards for EMC. For the problem that the intensity of electromagnetic radiation in
the meter with the THG at 36MHz is seriously more than National Standards, by studying the theory of radiation
emission and analyzing the formation mechanism of electromagnetic radiation interference, it proposes three restrain
measures: 1.the improvement of the Crystal oscillator's grounding measure; 2.adding a RC filter circuit to the Crystal
oscillator circuit; 3.the improvement of the tax's communication cable, solving the problem that radiation harassment the
taxi meter seriously exceeds. The experimental result demonstrates that the radiation intensity of tax meter improved
with the general measures meet the requirements of the national standard, making more than 32000 taxes in Tianjin
install this green meter, protecting the safety of staff and normal operation of the surrounding equipment.
Electromagnetic inhibition of high frequency thermal bonding machine
Show abstract
The traditional high frequency thermal bonding machine had serious radiation problems at dominant frequency, two
times frequency and three times frequency. Combining with its working principle, the problems of electromagnetic
compatibility were studied, three following measures were adopted: 1.At the head part of the high frequency thermal
bonding machine, resonant circuit attenuator was designed. The notch groove and reaction field can make the radiation
being undermined or absorbed; 2.The electromagnetic radiation shielding was made for the high frequency copper power
feeder; 3.Redesigned the high-frequency oscillator circuit to reduce the output of harmonic oscillator. The test results
showed that these measures can make the output according with the national standard of electromagnetic compatibility
(GB4824-2004-2A), the problems of electromagnetic radiation leakage can be solved, and good social, environmental
and economic benefits would be brought.
Research of a novel CMM with 3-PSS parallel mechanism
Penghao Hu,
Ling Yao,
Songyuan Li
Show abstract
A new 3-DOF parallel Coordinate Measuring Machine was proposed in this paper，which could realize 3D measured
with only one linear grating and one precision guide. According to its forward kinematics and complete
differential-coefficient theory, the error model was established; by deriving the inverse kinematic equations for the
Jacobian matrix, it has been proved that the mechanism has no singularity within the working space. The input parameter
errors and mechanical errors affecting the probe position accuracy are analyzed too. The prototype has been
manufactured and assembled after theoretical analysis, now it can finish basic motion and simple test, the further study is
in process, which will mainly focus on improvement of measuring accuracy and calibration method.
Error compensation for the linear error of a universal tool microscope’s scale system
Show abstract
The method of 1x asymmetry optical paths generating magnification error is employed in scale system
linear error compensation of universal tool microscope’s longitudinal coordinate.The
micro-displacements of scale iamges are achieved for compensation of scale linear error based on the
property of off-axis and out of focus and focal length inequality. The creative and ingenious optical
paths design is discribed in the paper . A detailed analysis of the principle of error compensation is
presented. Magnification error principle formula and defocus amount and off-axis aberration error
extension formula are also derived. The relationship between the calibration result and slope of formula
is obtained to benefit the analysis and application on-site.The influence caused by the change of
magnification parameters also are discussed in the paper. Indication error of one-meter longitudinal
coordinate can be achieved less than 2.5 um after compensation in using this method.
Image feature extraction method of planar target based on homography
Show abstract
Image feature extraction of target is the premise of parameter calibration of the cameras and sensors in vision
measurement. Because the spatial coordinates of features on the target are already known, the calibration mainly depends
on precise extraction of target image features and accurate matching to their corresponding spatial features. This paper,
which mainly discussed the planar target (circular feature target and square feature target) image, researched a new method
to achieve the feature extraction based on homography.
Firstly, the target plane can be defined as XY plane of the world coordinate system. According to the image
coordinates and their corresponding spatial coordinates of at least four corner positions on the target, homography
between the target plane and the image plane was solved
Secondly, the rough image coordinates of feature points on the image plane can be obtained by their corresponding
spatial coordinates. So the accurate corresponding relationship between the image plane and the space position was
established.
Finally, the accurate image coordinates of feature points were solved, via the least squares ellipse fitting (circular
feature target) or the corner detection algorithm (square feature target).
The experiments showed that this method can achieve precise extraction of planar target image feature points and
accurate matching to spatial feature points.
The application of micro-stepping for step-motor in the automatic blood viscosity measurement
Show abstract
In the automatic blood viscosity measurement system, the mechanical movements of moving parts are supported by stepmotors.
The step angle of step-motor can not meet the requirements of precise positioning of parts, so the introduction of
micro-stepping method is proposed to improve accuracy. At the same time, micro-stepping improves the running
performance of step-motor. In the system adopts A3977 which has decoder inner chip drives hybrid step-motor (twophase
four-shot). The most important feature of A3977 is that it integrates hardware micro-stepping inner chip, and the
mainly electrical structure is easy. The system adopts eighth step by A3977, and uses C8051 to control enable, direction
and step of step-motor.
Design and calibration of a novel piezoelectric six-axis force/torque sensor
Show abstract
This paper describes the design and the calibration of a novel parallel piezoelectric six-axis force/torque sensor. A new
force-sensing cell distribution model has been investigated: eight piezoelectric quartz crystal cells are uniformly
distributed along one circle line to get the spatial force information. The mathematic model of the method has been
deeply researched, established and calculated. In this paper, the negative step response method is calibrated to evaluate
the dynamic response of the sensor: the calibration force acting on the sensor is suddenly removed by breaking a brittle
material. Based on the experimental data of the calibration, the natural frequency, dynamic range as well as coupling
interference of the sensor are analyzed and discussed. The new force-sensing cell distribution model may overcome
some disadvantages of present six-axis force sensor, such as improving the overall stiffness of the sensing system, and
meanwhile, reducing the coupled interference.
Absolute distance measurement applying spectrally-resolved interferometry
Show abstract
A scheme is proposed for high-precision, absolute distance measurement for a theoretical arbitrary optical distance. The
approach utilizes a frequency stabilized Ti:sapphirez femtosecond pulse laser to provide a phase-locked summation of
discrete quasi-monochromatic light modes of consecutive frequencies, which is seen as an optical comb in the frequency
domain. We describe a new way of spectrally-resolved interferometry devised to measure the optical path delay between
two consecutive ultrashort pulses with high precision, which leads to an accurate means of absolute distance
measurement. A FPE(Fabry-Perot Etalon) filters smaller frequency from the broad-bandwidth femtosecond laser pulse
produced. The dispersive interferometry data permits the unambiguous measurement range to be significantly increased
compared with the dispersive interferometry used in white light to measure an absolute distance. Preliminary
experimental results are reported for a spectrally-resolved interferometry demonstrating the principle of operation and
yielding a non-ambiguity range of 5.75 mm and an associated resolution of nanometer level.
Micro-vision-based displacement measurement with high accuracy
Show abstract
The micro-motion stages are widely used in micro/nano manufacturing technology. In this paper, an integrated approach
for measuring micro-displacement of micro-motion stage that incorporates motion estimation algorithm into the
computer microvision is proposed. At first, the basic principle of the computer microvision measurement is analyzed.
Then, a robust multiscale motion estimation algorithm for micro-motion measurement is proposed. Finally, the microdisplacement
of the micro-motion stage based on the piezoelectric ceramic actuators and the compliant mechanisms is
measured using the integrated approach. The maximal bias of the proposed approach reached 13 nm. Experimental
results show that the new integrated method can measure micro-displacement with nanometer accuracy.
Localization/mapping motion control system for a mobile robot
Show abstract
The objective of this paper is to design a mobile robot with automatic motion behaviors and obstacle avoidance functions. The robot is also able to make the SLAM (Simultaneous Localization And Mapping) at an unknown environment. The robot position is calculated by the developed software program from the motor encoders. An obstacle avoidance controller is developed by the fuzzy theory. A LRF(laser ranger finder) is installed on the robot. The sensing data of this LRF are applied to calculate the environmental information for the obstacle avoidance controller. Then, the ICP (Iterative Closest Point) algorithm is applied to compare the position error of the environmental data in order to obtain the estimated position of the LRF. Finally, these estimated position data are used to calculate the final SLAM of this mobile robot. Both the simulation and experimental results show that this developed robot system work very well. Key word: SLAM, obstacle avoidance, ICP(Iterative Closest Point), LRF(laser range finder).
Contact-flatted measurement of eye stiffness based on force–displacement relationship
Show abstract
This paper presents a noninvasive approach in vivo measurement of eye stiffness based on a force–displacement
relationship, which is based on a new contact-probe method of simultaneously measuring the static force and
displacement. First, a simple spherical eye model is introduced for deriving analytical eye stiffness when a static force is
applied to an eye. Next, a measurement system for simultaneously measuring force and displacement when a probe is
pressed onto the eye is presented. Static eye stiffness is defined which based on the measured force–displacement
relationship. A photoelectric probe transducer acts as displacement detector. A 16-bit single-chip microprocessor with
E2PROM in the electronic circuit played the role of a nucleus, which stored the program instructions and the interrelated
data. Laboratory experiments were carried out on a simulated eyeball connected to a hydraulic manometer to obtain
intraocular pressure at different levels. The experimental results show that the measured eye stiffness nicely matches the
analytical result.
Fast parallel 3D profilometer with DMD technology
Show abstract
Confocal microscope has been a powerful tool for three-dimensional profile analysis. Single mode confocal microscope
is limited by scanning speed. This paper presents a 3D profilometer prototype of parallel confocal microscope based on
DMD (Digital Micromirror Device). In this system the DMD takes the place of Nipkow Disk which is a classical parallel
scanning scheme to realize parallel lateral scanning technique. Operated with certain pattern, the DMD generates a
virtual pinholes array which separates the light into multi-beams. The key parameters that affect the measurement
(pinhole size and the lateral scanning distance) can be configured conveniently by different patterns sent to DMD chip.
To avoid disturbance between two virtual pinholes working at the same time, a scanning strategy is adopted. Depth
response curve both axial and abaxial were extract. Measurement experiments have been carried out on silicon structured
sample, and axial resolution of 55nm is achieved.
Low velocity intense rubidium beam source from a 3D magneto-optical trap
Show abstract
We present an experimental set-up for the production of a beam source of cold 87Rb atoms, which is formed from a
trapped cold atomic cloud in a three-dimensional (3D) magneto-optical trap (MOT). Via a radiation pressure difference
generated by a specially designed leak tunnel along one trapping laser beam, the atoms are pushed out continuously with
low velocity and high flux. The beam was measured to have a mean velocity of 12m/s and a longitudinal velocity spread
of about 3m/s under nominal experimental conditions, based on the fluorescence and the time of flight (TOF)
technologies. And its flux can be tuned by adjusting the MOT parameters from 108 to 109 atoms/s. Especially the beam
performance dependence on trapping laser detuning and power is experimentally studied.
The machining precision analysis of the ion beam figuring system
Show abstract
The ion beam figuring machine is a kind of high precise machining facility for optical components. In the field of optical
fabrication, the machining precision is always an important capability for the machining facility. The basic structures and
working principles of the ion beam figuring system are primarily introduced. And then, various errors which may reduce
the final machining precision have been analyzed through theories analysis and computer simulations. The errors
include: the approximate error from the discrete compute model to the actual continuum machining model; the system
error and random error of the high precision 3-axis motion stage which drives the ion source; the system error and
random error of the material removal rate of the ion source. A set of potential error parameters has been given for each
part of the ion beam figuring system. By using this set of parameters, it is possible to reach the nano-level machining.
The precision analysis in the paper will be a reference for ion beam figuring.
An improved SIFT descriptor
Show abstract
In order to improve the robustness and real time performance of SIFT based image registration algorithms, a new
descriptor is proposed. We compute the new descriptor for a log-polar location grid with 3 bins in radial direction (the
radius set to 3, 6 and 8) and 12 in angular direction, which results 36 location bins. Firstly, the 3×12 log-polar location
grid is rotated to align its dominant orientation to a canonical direction in a different way with SIFT with less
computational complexity. The keypoint dominant orientation and its orthogonal orientation is defined as the x and y
directions of the descriptor’s local coordinate system. After that a 3×3 grid is rotated to align the dominant
orientation ,and then the rotated 3×3 grid is translated to each pixel within the local 3×12 log-polar location grid.
Therefore the local 3×12 log-polar location grid is rotated to align the dominant orientation and the rotation invariance is
achieved. Secondly, compute the gradients in x and y directions using the rotated 3×3 grid for each pixel within the
keypoint local neighborhood, so each pixel constitutes a gradient vector with 2 dimensions. Thirdly, use the distance
from each pixel to the corresponding keypoint and a Gaussian function to assign a weight to the gradients, and then
compute the gradients location histogram for the 36 location bins in the 3×12 log-polar grid. Finally, a descriptor with 72
dimensions is constituted and the descriptor is normalized to achieve illumination invariance. The experimental results
show that the computational complexity of the new descriptor is reduced about 30% compared with the standard SIFT
descriptor while the performance is favorably compared to the standard SIFT descriptor .
A novel linear displacement sensor
Ji-sen Yang,
Jing Zhang,
Xi-hou Chen,
et al.
Show abstract
With development of time grating technology in the past 10 years, the theory of using time to
measure spatial displacement has been completed greatly. In the study of time grating, one novel
linear displacement sensor is proposed based on the measurement principles of time grating. The
measurement principles of linear displacement are similar to that of angular displacement. Both of
them need one endless coordinate with uniform velocity. The theory of linear AC motor is used, and
the three-phase winding with equal division space of 120° and three-phase exciting signal with
uniform time are utilized to generate the endless moving coordinate with uniform velocity. The
magnetic traveling wave arises from the left endpoint and disappears in the right endpoint, and it
travels pole pitch distance of W during the periodic time of T with the uniform velocity. When
magnetic traveling wave passes by the static probe and the moving probe, the electric signals will be
induced on the winding, respectively. Therefore, the linear displacement can be achieved by
comparing the phase between the two output induced signals from he static probe and the moving
probe. Furthermore, in order to improve the machining technique, four kinds of winding framework
are designed to employ. The experimental results show that advantages and disadvantages both exist
in the design methods and the precision of experiment results reaches ±2μm. The next study plan is
to choose the most excellent design method through further experiments and improve the precision
of displacement sensor greatly.
Semi-automatic inspecting instrument for watch escape wheel based on machine vision
Show abstract
Escape wheel as a typical precision micro-machinery part is one of the most precision parts in one mechanical watch. A
new inspecting instrument based on machine vision technology used to achieve semi-automatic inspection of watch
escape wheel is introduced in this paper. This instrument makes use of high resolution CCD sensor and independent designed
lens as the imaging system. It can not only achieve to image an area with 7mm diameter once, but also has the resolving
power in micrometer and cooperates with two-dimensional moving station to achieve a continuous and automatic
measurement of the work pieces placed in array type. In which, the following aspects are highlighted: measuring princeple
and process, the basic components of array type measuring workbench, positioning process and verticality, parallelism
and other precision adjusting mechanism. Cooperating with novelty escape wheel preparation tool this instrument
forms an array type semi-automatic measuring mode. At present, the instrument has been successfully running in the
industry field.
Investigation of bromide's spectra by high resolution UV-laser
Show abstract
Experimental investigation has been carried out for dissociation/ionisation of methyl bromide using time of flight mass
spectrometer, then, the mass signals were assigned to H+, CHm+ (m= 0-3), iBr+ (i = 79, 81), and the main processes of
multi-photon ionization and dissociation of CH3Br were given.
On-line detection for LED module based on machine vision
Show abstract
LED module board is the basic composition unit of LED panel, and the quality of module board is the key and premised
for panel to obtain a display of good quality. In this paper, based on the practice of project, use median filtering to filter
the pulse and salt-pepper noises, which are produced in the process of image acquisition, and use the adaptive OTSU to
segment images, adjust the angle between standard position image and the image caused by table vibration with
Fomier-Mellin method, and process results adjusted with bilinear interpolation method. Results show that, using the
image segmentation method can accurately determine the threshold image segmentation, results meet factory detection
requirements, the method can be used in the industrial field of application of real-time measurement system with a higher
promotional value.
Bubbles image processing and parameters measurement based on the high-speed photography
Show abstract
In this paper, the image processing and parameters measurement method of rising bubbles has been studied. The original
bubble image captured is pre-processed with image gray processing, difference image and median filter. According to
the characteristic of bubble images, the improved Otsu method with dynamic threshold compression is used for image
binarization, and the scan line seed fill algorithm is combined with morphological image processing to implement holes
filling. Simultaneously, automatic identification technique of bubble feature regions is proposed based on the edge area
attribute. After the aforementioned image processing algorithms and processes, the shape feature parameters of bubbles
such as perimeter, area, circularity, and mass center coordinate can be extracted effectively as well as the measurement
of bubble velocity.The experimental results show that the method is easy, robust and effective, and the parameters of
bubbles can be measured precisely.
Rigorous electromagnetic analysis of metallic cylindrical focusing micromirrors designed by a modified focal-length function
Show abstract
Through exploiting a modified focal-length function, two-dimensional metallic cylindrical focusing micromirrors
(MCFMs) with different preset focal depths are designed. Rigorous electromagnetic theory and the boundary element
method are applied to analyzing the focal characteristics, including the actual focal depth, the relative focal depth, the
focal spot size and the diffraction efficiency. Through setting the preset focal depth to be positive or negative, numerical
results reveal that the designed MCFMs can successfully modulate the optical field distribution to achieve a long axial
focal depth or increased lateral resolution, respectively. In addition, due to the inherent achromatic aberration property of
the metallic reflective system, the common long-focal-depth region of the designed MCFM under multiwavelength
illumination is greatly enlarged, in comparison with a dielectrically cylindrical microlens. It is expected that the designed
MCFMs should have many practical applications in micro optics systems.
The capillary blood rheological measurement system
Show abstract
The study of hemorheology is becoming the hot spot of medical research and biomedical engineering. A high
performance full-automatic capillary blood rheological measurement system which is based on the principle of the
Hagen-Poiseuille law is introduced in this paper. The system integrates the computer control technology and the
precision measurement technology. The slave module of the system hardware and software are designed by the module
idea. The application program in the computer achieves man-machine interaction and the lower computer controls the
slave module of the system. The experimental results demonstrate that the repeatability error of the system is 1.309% and
the quoted error of the system is 0.021%.
Turbine blade tip clearance measurements using skewed dual optical beams of tip timing
Show abstract
Optimization and active control of the clearance between turbine blades and case of the engine is identified, especially in
aerospace community, as a key technology to increase engine efficiency, reduce fuel consumption and emissions and
increase service life .However, the tip clearance varies during different operating conditions. Thus a reliable non-contact
and online detection system is essential and ultimately used to close the tip clearance control loop. This paper described a
fiber optical clearance measuring system applying skewed dual optical beams to detect the traverse time of passing
blades. Two beams were specially designed with an outward angle of 18 degree and the beam spot diameters are less
than 100μm within 0-4mm working range to achieve high signal-to-noise and high sensitivity. It could be theoretically
analyzed that the measuring accuracy is not compromised by degradation of signal intensity caused by any number of
environmental conditions such as light source instability, contamination and blade tip imperfection. Experimental tests
were undertaken to achieve a high resolution of 10μm in the rotational speed range 2000-18000RPM and a measurement
accuracy of 15μm, indicating that the system is capable of providing accurate and reliable data for active clearance
control (ACC).
Real-time specified object tracking system under complex background
Show abstract
A new approach is proposed in real-time specified object tracking system under auto dome rotation freely. When it is
necessary to track objects in occlusion conditions or with high speed by real-time system, it is not always possible to
using particle filter or mean shift algorithm both of which are widely used. The key idea of the presented research work
is to integrate the advantages of mean-shift algorithm and particle filter. Using mean shift algorithm to iterate the
particles generated by particle filter repeatedly until stable, which could efficiently reduces the number of sampled
particles. Therefore the system designed in this paper can track the objects in occlusion conditions or with high speed,
and the computational cost is greatly reduced, moreover, an adaptive occlusion detecting algorithm, which update the
model when the object is in occlusion makes the system more robust. The experiment results demonstrate that the object
tracking system in this paper can meet the tracking requirements when the object is moving, rotating or in partial
occlusion. The error of this system is less than 0.859%, it also proved the combing method is effective and steady.
Self-calibration method of two-dimensional grid plate
Guoqing Ding,
Xin Chen,
Lihua Wang,
et al.
Show abstract
A two-dimensional grid plate can offer an X-Y position standard where grids are aligned orthogonal to each other. It is
important to ensure the positional accuracy of the grid plate when the grid plate is used to calibrate planar movement
systems, such as vision measuring machines and scanning probe microscopes. Existing algorithms for self-calibration
employ the discrete Fourier transform, which is complicated and has poor noise suppression capability. We have
developed an algorithm that can achieve exact self-calibration for a two-dimensional grid plate using the least squares
method when there is no random noise. In the presence of random noise, the algorithm still presents an excellent
capability for noise suppression. As an extension of the classic three-location measurement, the algorithm can be applied
to four- or five-location measurements, which reduce measurement uncertainties. The error propagation characteristic of
the random errors has been investigated in the case of different measurement strategies. According to the simulation
results, the mean error propagation ratios are less than 1 when the array size of the grid plate is less than 32×32. Finally,
the influence of the scale errors of the planar movement system is discussed.
Piezoelectric inchworm-type probe-approaching stepper
Xing Fu,
Wenlan Xiao,
Linyan Xu
Show abstract
A piezoelectronic inchworm-style stepper was designed for probe approaching in scanning probe microscope(SPM). The
whole system consists of mechanical structures, hardware control units and PC software control units. Flexible hinges
and three PZT stacks were used to constitute the stepper. ANSYS was utilized to analyze and optimize the structure of
the mechanism. Three synchronous timing sequences were formed to drive the piezoelectric stacks. The performance of
the stepper was tested by the laser interferometer. The deviation of each step is less than 31.2nm. With the advantages of
no lubrication, less calorific value and high precision, its potential application is ultra-high vacuum environment.
A free-form total internal reflection (TIR) lens for illumination
Guiying Yu,
Shushu Ding,
Ji Jin,
et al.
Show abstract
Design of uniform illumination is one of the most crucial topics for LED to replace the traditional light sources. Based on
the theory of Etendue from non-imaging optics and the edge ray principle, in combination with the theory of freeform
surfaces, this paper sets up mathematical models of the refractive freeform surface lens and the total internal reflection
(TIR) freeform surface lens, which are solved by numerical method to obtain the shape of surfaces, simulates the optical
systems by 3D modeling and the ray-tracing software Trace-pro, and analyzes the lighting effects. The results show that
both of the lens can generate uniform illumination in the cone of 120° spatial angle. When the diameter of the emitting
surface of the LED is less than 2mm, the refractive freeform surface lens can generate uniformity above 0.8 and energy
efficiency above 0.83; when the diameter is less than 4mm, the TIR freeform surface lens can generate uniformity above
0.7 and energy efficiency up to 0.86.
Numerical analyses for thinned fiber Bragg grating under uneven surrounding refractive index environment
Show abstract
Based on the fiber waveguide models, a modified transfer matrix method was utilized to calculate the reflection spectrum
of the thinned fiber Bragg grating (ThFBG) under the uneven surrounding refractive index (SRI) environment. Tow SRI
ranges, including the high SRI region (from 1.42 to the fiber cladding index) and the low ones (from 1.33 to about 1.36),
were considered. Numerical results showed that the responsive characteristics of the reflectance spectrum of the ThFBG
were closely related to the properties of the SRI distribution, first, the original reflection spectrum of the ThFBG would
split into many tinny resonant peaks and the reflectance spectrums are asymmetric since the uneven SRI distributions,
second, the number of the resonant peaks, the decline of the amplitude, and the degree of the asymmetric of the
reflectance spectrums would increase as the increase in the SRI gradient and the D-value of the SRI between the tow
ends of the ThFBG. The same numerical approach could be used to analyze the responsive characteristics of the ThFBG
under the uneven medium environment where the SRI distribution was any other functions.
A 3D nano driving system with large-stroke
Shuzhen Wang,
Ziqiang Du,
Tiebang Xie
Show abstract
To satisfy the need of precision displacement, a 3D Nano driving system, which including metrological vertical scanning
system and coplanar 2D precision stage with large-stroke and nanopositioning resolution, is developed in this paper. The
coarse-fine dual-stage actuators have been applied in the 3D Nano driving system in X, Y and Z directions. The
servomotors combining with precision lead screws and linear guides are used to actuate the coarse driving, and
piezoelectric actuators combining with parallel board flexure hinges are used to actuate the fine driving. Three laser
interferometers are used to measure the displacement in X, Y and Z directions respectively. The structure and principle
of the system is introduced and the displacement range and displacement resolution of the system are also analyzed in
details. The 3D Nano driving system has been successfully applied in the white light interference based atomic force
probe scanning measurement system for ultra-precision surface topography developed in our laboratory. The
experimental results show that the nano-driving in X, Y, Z directions can be realized by the 3D Nano driving system.
Underwater photogrammetric theoretical equations and technique
Show abstract
In order to have a high level of accuracy of measurement in underwater close-range photogrammetry, this article deals
with a study of three varieties of model equations according to the way of imaging upon the water. First, the paper makes
a careful analysis for the two varieties of theoretical equations and finds out that there are some serious limitations in
practical application and has an in-depth study for the third model equation. Second, one special project for this
measurement has designed correspondingly. Finally, one rigid antenna has been tested by underwater photogrammetry.
The experimental results show that the precision of 3D coordinates measurement is 0.94mm, which validates the
availability and operability in practical application with this third equation. It can satisfy the measurement requirements
of refraction correction, improving levels of accuracy of underwater close-range photogrammetry, as well as strong antijamming
and stabilization.
Design of an analogue contact probe for nano-coordinate measurement machines (CMM)
Show abstract
A new high precision analogue contact probe with long measurement range that is able to measure miniature components
on a micro/nano-coordinate measuring machine (CMM) is proposed. This analogue probe is composed of a fiber stylus
with a ball tip, a mechanism with a wire-suspended floating plate, a two-dimensional angle sensor and a miniature
Michelson linear interferometer. The stylus is attached to the floating plate. The wires experience elastic deformation
when a contact force is applied and then the mirrors mounted on the plate will be displaced, which displacements can be
detected by two corresponding sensors. Each component of the probe is designed, fabricated and assembled in this
research. Base on the design requirements and stiffness analysis of the probe, several constrained conditions are
established, and optimal structure parameters of the probe are worked out. Simulation and experimental results show that
the probe can achieve uniform stiffness, ±20μm measurement range and 1nm resolution in X, Y and Z directions. The
contact force is less than 50μN when the ball tip is displaced by 20μm. It can be used as a contact and scanning probe on
a Micro/Nano-CMM.
Repeatability test of in-line gear measuring machine
Show abstract
The In-line Gear Measuring Machine (GMM) based on the double-flank gear rolling test with many degrees of freedom
was developed to inspect the gears fast in workshop. The radial composite deviations and tangential deviations can be
evaluated during one inspection. To evaluate the measuring machine, the repeatability test is the most critical. Many
factors should be notified in the repeatability test, such as mechanism accuracy, clearance between bore and arbor,
accuracy of master gear and the gear to be inspected, spring stiffness and damping coefficient, stability of the air
pressure, measuring force, starting point of measurement, speed and rotation direction of gear, clean and no stain, etc..
After taking account of the above factors, the repeatability test of GMM was implemented.
Application of wavelet analysis in laser-generated ultrasonic
nondestructive testing
Xianglin Tan,
Mengchun Pan,
Shitu Luo,
et al.
Show abstract
Laser-generated ultrasonic technology possesses incomparable advantages to many conventional testing methods of
complete non-contact, fast response, non-destruction, wide band range, high precision and low cost, which is widely
used to test the defects of aerocraft’s components. However, the actual laser ultrasound signal is often mixed with a
variety of noise and interference, which brings certain difficulty to material characterization and flaw identification. In
order to de-noise laser-generated ultrasonic signal and enhance the detection sensitivity and reliability, wavelet analysis
is applied to signal processing in this paper. The paper discusses the wavelet threshold de-noising methods, and the
features of two traditional wavelet shrinkage methods----soft threshold and hard threshold, are analyzed in wavelet
domain. Then an improved wavelet threshold function method is proposed on the basis of the two traditional threshold
methods. According to the characteristics of the signal, db6 wavelet and 4 levels’ decomposition are selected to complete
the signal analysis. The functions of soft threshold, hard threshold and the improved threshold are employed in wavelet
coefficients threshold processing respectively. Based on the analysis and comparison of each denoised figure and
statistical property, the improved method can get a remarkable effect in signal de-noising is proved. It is concluded by
theory analyzing and experiment research that the improved wavelet threshold function method has more advantages in
laser ultrasonic signal de-noising compared with the two traditional threshold methods, which not only overcomes the
shortcoming of discontinuity of hard threshold method, but also decreases the fixed bias between estimated wavelet
coefficients and decomposed wavelet coefficients of soft threshold method.
Design of a cryogenic absolute prism refractometer for infrared optical materials
Show abstract
In order to enable high quality infrared lens designs at cryogenic temperature, we decided to study the IR materials’
optical properties, such as the refractive index, the thermo-optic coefficient (dn/dT) etc. As a matter of fact, accurate
precision refractive index data for infrared optical materials at cryogenic temperatures is scarce, so we decided to design
a cryogenic absolute prism refractometer for infrared optical materials.
Considering the most accurate and precise measurements of the real part of the refractive index, n, optical materials are
obtained through minimum deviation refractometry, we decided to choose this classic refractometer for our cryogenic IR
materials index measuring. Given the thermo-optic coefficient of many IR materials, which was reported by NASA, the
measurement precision is at least 10-3. In order to achieve this precision, the error of apex angle of sample prism and
deviation angle must be less than 20 arc-second. The thermal stress of the prism must be in control, or the volume
change of the prism may lead to stress birefringence (photo-elastic effect). The bandwidth of IR source must be less than
20nm and the error caused by dispersion (dn/dλ) will generally be negligible in our system.
The hardware system consists of 5 subsystems: the rotating sample chamber subsystem, the rotating plat mirror
subsystem, the cryogenic vacuum subsystem, auto control subsystem, exit image collimation subsystem. Finally, the
system is designed to measure IR materials’ indices between 1-4, at the wavelength of 1.0-12μm, at room (300K) and
cryogenic temperature (100K), with a precision of 10-4.
Concept of a novel nano displacement magnetostrictive actuator with self-sensing function
Show abstract
Giant magnetostrictive materials can be used in the micro driving or sensing system for that the shape of materials
changes under the different external magnetic field, which is called one effect of magnetostriction. As for the common
Terfenol-D bars, the magnetostriction is expressed by the length change in the direction of the magnetic field, and the
value of length change is too small to be detected. This paper presents a design of nano scale driving and measuring
system which utilizes the thick film resistor (TFR) strain gauge mounted on the surface of Terfenol-D bar to measure the
strain change of giant magnetostrictive materials directly, the in-situ measuring method has better flexibility and
sensibility than indirect measuring methods such as capacitor sensor or other displacement measuring devices. A DSP
based weak signal processing system has been developed to excite the micro displacement sensing system and calculate
the strain of Terfenol-D bars from the signal output from thick film strain gauge instantly. The design scheme improves
the resolution and accuracy of deformation measurement of the Terfenol-D bar, which is fundamental to the control of
system and fulfills the requirements of real-time precise driving or sensing.
High precision measurement system based on coplanar XY-stage
Show abstract
A coplanar XY-stage, together with a high precise measurement system, is presented in this paper. The proposed
coplanar XY-stage fully conforms to the Abbe principle. The symmetric structural design is considered to eliminate the
structure deformation due to force and temperature changes. For consisting of a high precise measurement system, a
linear diffraction grating interferometer(LDGI) is employed as the position feedback sensor with the resolution to 1 nm
after the waveform interpolation, an ultrasonic motor HR4 is used to generate both the long stroke motion and the nano
positioning on the same stage. Three modes of HR4 are used for positioning control: the AC mode in continuous motion
control for the long stroke; the gate mode to drive the motor in low velocity for the short stroke; and the DC mode in
which the motor works as a piezo actuator, enabling accurate positioning of a few nanometers. The stage calibration is
carried out by comparing the readings of LDGI with a Renishaw laser interferometer and repeated 5 times. Experimental
results show the XY-stage has achieved positioning accuracy in less than 20nm after the compensation of systematic
errors, and standard deviation is within 20 nm for travels up to 20 mm.
An interference signal processing method for displacement measurement by dual wavelength and single grating
Show abstract
Displacement measurement by dual wavelength and single grating integrates the single grating diffraction theory and the
heterodyne interference theory. By taking advantage of the two theories, it solves the contradiction between large range
and high precision in grating displacement measurement quite well. In order to obtain nanometer resolution and
nanometer precision, high-power subdivision of interference fringe must be realized accurately. According to phase
demodulation theory for heterodyne interference signal, a digital phase measuring method is proposed by combining
frequency-mixing technique and pulse-filling method. The whole signal processing part, which is based on FPGA and
PLL, has been designed to realize the integer period measurement and high-powered subdivision of the decimal phase.
Through experiments, it is validated that the phase range is [-180°, 180°], and the phase measurement resolution and the
phase precision are above 0.03° and 0.1°, respectively. Moreover, the displacement measurement resolution and the
displacement precision, corresponding to the phase indexes, are 0.167nm and 0.556nm, respectively.
Design for H type co-planar precision stage based on closed air bearing guideway with vacuum attraction force
Bin Zhang,
Zhaoyao Shi,
Jiachun Lin,
et al.
Show abstract
The accuracy of traditional two-dimensional precision stage is limited not only by the accuracy of each guideway but
also by the configuration of the stage. It is not easy to calculate and compensate the total accuracy of the stage due to the
complicated influence caused by the different position of the slides. An air bearing guideways with vacuum attraction
forces has been designed with closed slide structure to enhance the stiffness and avoid the deformation caused by the
weight of slide and workpieces. An H style two-dimension ultra-precision stage with co-planar structure has been
developed based on the air bearing guideways to avoid the multi-influence by the axes. Driven by linear motors, the
position of the workpiece is encoded by length scales with resolution of 50nm and thermal expansion of 0.6 μm/m/°C (0
°C to 30 °C). The travel span of the stage is 320x320mm, during which each axis has a positioning accuracy of ±1μm, a
repeatability of ±0.3μm and a straightness of ±0.5μm. The stage can be applied in precision manufacturing and
measurement.
Suppression research of arrival angle for free space optical communication
Show abstract
Free space optical communication systems have been used not only in the space communication link but also in
the terrestrial long-distance network, because channel transmission medium of communication is atmosphere,
atmospheric pressure and temperature vary randomly, which cause fluctuation of arrival angle, APT (Acquisition、
Pointing and Tracking) technology makes the communication terminals aim each other accurately, fine tracking is the
core component of APT system. In order to assure success of the communication link, the fine tracking system requires
tracking accuracy of sub-micro radian to mitigate the effect of arrival angle for communication beam. In the paper, the
construction and working principle of fine tracking system based on FPGA are introduced and analyzed, a novel adaptive
fuzzy network algorithm is introduced, the weights of PID parameters can be adjusted on real time. In the terrestrial
16km free space optical data link, efficiency of fiber coupling is enhanced obviously, the tracking precision reaches submicro
radian level, the experiment is demonstrated successfully, and the experimental results show the system is robust.
A tunable external cavity laser using a micromachined silicon flexure for atomic spectroscopy
Show abstract
This paper reports a novel external cavity diode laser system for applications in atomic physics that employs a
micromachined silicon flexure to sweep the laser frequency near the rubidium absorption spectrum. The advantages of
using a silicon flexure are its simple microfabrication process and reduction of the overall size of the laser system. The
results demonstrate the 87Rb, 85Rb (rubidium) D2 line absorption at 780 nm in an atomic optics test experiment. Our
novel laser system design has a size of 26.3 x 20 x 20 mm. The wavelength can be tuned and swept from 780.2533 to
780.2344 nm equivalent to 9.31 GHz using only piezoelectric transducer PZT actuators integrated on the silicon flexure.
The deflection of the silicon flexure is 157.45 nm. The advantage of combining a VHG and a silicon flexure is that the
frequency can be coarsely tuned to 780.24 nm and swept at this center frequency with a range of 9.31 GHz by PZT.
Moreover, the frequency fine tuning can be achieved by changing the VHG temperature to observe the rubidium
spectrum. The laser output power is measured as 9.72 mW at 780.24385 nm.
Effect of plane height and incident angle of structure laser on measurement of step-style work piece based on computer-vision
Show abstract
Based on computer-vision technology, the paper studies the effect of plane height error and structure
laser incident angle on the measurement of step-style work piece, which has geometric dimensions on
different planes. Through the calibration, the relationship of different heights corresponding to
two-dimensional plane calibration parameters is established, and the effect of the error of the plane
height in the measurement is analyzed, the experiment result demonstrates that when the error of the
height is less than 0.1mm, the effect is trivial to the dimension measurement result; The paper also
studies the influence of the structure laser incident angle on the measurement. The result of
experiments shows that with the increase of the structure laser incident angle, intercept value of any
two contour lines which are formed by the incident laser corresponding to two different heights on
measured work piece decreases and the world coordinates offset increases but the absolute error is
trivial too when the incident angle varies from 30° to 60°.
Study on the properties of the normalized reflectivity of fiber Bragg
grating based on evanescent wave
Show abstract
Based on the optical waveguide theory and the FBG mode coupling theory, a rigorous analysis of the reflectivity of the
fiber Bragg grating (FBG) with different diameters were presented. In conditions of cladding etched and core etched, the
power attenuation properties of the FBG based on evanescent wave were analyzed. The normalized reflectivity of the
FBG, which was the function of the surrounding refractive index (SRI) and the diameter of the FBG, was derived. The
theoretical results exhibited that the normalized reflectivity become smaller as the increase of the SRI, and the deeper the
FBG was etched, the smaller the normalized reflectivity was. Thus, we can make the conclusion that both the increase of
the SRI (small than the cladding refractive index) and the etched depth can reduce the intensity of light propagating in
the fiber and enhance the interaction between the evanescent wave and the surrounding medium, leading the sensitivity
of the sensor to increase. In addition, theoretical simulation showed good consistency with the experimental
characterization. The proposed study of the normalized reflectivity properties of FBG based on evanescent wave is
significant in improving the sensitivity of FBG.
Displacement measurements of highway bridges using digital image correlation methods
Show abstract
Digital image correlation methods (DICMs) are important tools in experimental solid mechanics. DICM is becoming
very versatile and cost effective due to the dramatic improvement over the digital cameras. Current study applies DICMs
to displacement measurements of full-scale concrete beams. Computer programs are implemented and tested against the
contact measurements using a linear variable differential transformer (LVDT). The calculated displacements agree with
the LVDT measurements that the difference is mostly within 3%. The DICM programs produce similar displacement
fields to those obtained using two computer codes written by other researchers. The DICM programs compute a singlepoint
in merely seconds while completing the displacement calculation for a whole-field region of one mega pixels in
one hour. Additional tests on the vertical displacement of a highway bridge also achieve a reasonable result which can be
extended to health monitoring of bridges.
Singular spectrum and singular entropy used in signal processing of NC table
Show abstract
NC (numerical control) table is a complex dynamic system. The dynamic characteristics caused by backlash, friction and
elastic deformation among each component are so complex that they have become the bottleneck of enhancing the
positioning accuracy, tracking accuracy and dynamic behavior of NC table. This paper collects vibration acceleration
signals from NC table, analyzes the signals with SVD (singular value decomposition) method, acquires the singular
spectrum and calculates the singular entropy of the signals. The signal characteristics and their regulations of NC table
are revealed via the characteristic quantities such as singular spectrum, singular entropy etc. The steep degrees of singular
spectrums can be used to discriminate complex degrees of signals. The results show that the signals in direction of
driving axes are the simplest and the signals in perpendicular direction are the most complex. The singular entropy values
can be used to study the indetermination of signals. The results show that the signals of NC table are not simple signal
nor white noise, the entropy values in direction of driving axe are lower, the entropy values increase along with the
increment of driving speed and the entropy values at the abnormal working conditions such as resonance or creeping etc
decrease obviously.
The Rockwell hardness primary national machine according to the new international definition
Show abstract
According to the new definition of Rockwell hardness given by the International Working Group on Hardness
(WGH), the new Rockwell hardness national primary standard machine in the National Institute of Metrology is
presented in this paper. A tooth-belt is used to reduce the vibration. The loading monitor system, the PLC control system
and the laser measuring system are designed to raise the measuring precision. Experiments show that the Rockwell
hardness standard machine based on this method can meet the requirements of the new definition and accomplish a
high stability and measuring precision.
DSP based lunar sampling control system for the coiling-type sampler
Show abstract
The paper develops a control system based on DSP28334 for lunar sampling, and provides the
main structure of it. The critical hardware and software design of the system are introduced in detail. The
emphasis is placed on the design and realization of the vibration control of the coiling-type sampler in the
process of lunar sampling. A control strategy which combines manual-control and local autonomous
control is applied for the lunar sampling control. And the sampling mechanism being controlled can
realizes multi-motor units working at time-sharing, which reduces the power comsumption and
increases the stability of the sampling system greatly. The practical application of the control strategy
used for the coiling-type sampler is verified by the finite element analysis. The experiments results show
that the system works with low power consumption and high efficiency, and the proposed strategy
enables greater depth and better efficiency during sampling.
Air compressor multi-pattern smart monitor
Show abstract
The device is controlled by TMS320F2812 microprocessor. It mainly includes signal acquisition circuit, keyboard
circuit, Chinese / English LCD display circuit, the calendar clock circuits, alarm circuits, relay output circuit,
communications interface circuits, DI / DO circuit, power circuit and CPU circuit and so on. In addition, the device
integrates a sensor transmission circuit, so it can directly connect with temperature pressure sensors to achieve
high-precision measurement and monitoring. According to needs of users, it can work in different modes without the
additional controller respectively. The equipment can communicate with each other by CAN bus or RS485. It mainly can
realize the control and analysis of equipment status, failure predication and diagnosis, information management, etc.
Research on full closed loop NC system of linear cutting machine for high accuracy internal gear machining
Show abstract
An appropriate model is established to analyze angular displacement error in machining process of linear cutting
machine in paper. Analysis results are as follows: as the radius of machining decreases, the angle errors become larger.
For the same radius of machining, the increasing angular indexing causes increasingly larger indexing error. When θ is
45 degree, indexing error reaches the maximum, and after 45 degree, indexing error begins to reduce. In order to
improve the indexing accuracy of internal gear machining and automation level, full closed-loop numerical control
system of linear cutting machine with high precision for internal gear machining is designed. The whole system consists
of three parts including molybdenum wire automatic measurement and compensation system, hollow rotary table-type
intelligent time grating sensor and control system of linear cutting machine. Here the time grating sensor provides angle
information feedback for full closed-loop control system. The experimental results demonstrate that the linear cutting
machining of internal gear is realized with full-automatic, high-precision and low-cost.
Estimation of the convergence order of rigorous coupled-wave analysis for OCD metrology
Show abstract
In most cases of optical critical dimension (OCD) metrology, when applying rigorous coupled-wave analysis (RCWA) to
optical modeling, a high order of Fourier harmonics is usually set up to guarantee the convergence of the final results.
However, the total number of floating point operations grows dramatically as the truncation order increases. Therefore, it
is critical to choose an appropriate order to obtain high computational efficiency without losing much accuracy in the
meantime. In this paper, the convergence order associated with the structural and optical parameters has been estimated
through simulation. The results indicate that the convergence order is linear with the period of the sample when fixing
the other parameters, both for planar diffraction and conical diffraction. The illuminated wavelength also affects the
convergence of a final result. With further investigations concentrated on the ratio of illuminated wavelength to period, it
is discovered that the convergence order decreases with the growth of the ratio, and when the ratio is fixed, convergence
order jumps slightly, especially in a specific range of wavelength. This characteristic could be applied to estimate the
optimum convergence order of given samples to obtain high computational efficiency.
3D fiber probe for multi sensor coordinate measurement
Show abstract
Increasing manufacturing accuracy requirements enforce the development of innovative and highly sensitive measuring
tools. Especially for measurement with sub micrometer accuracy, the sensor principle has to be chosen appropriately for
each measurement surface. Modern multi sensor coordinate measurements systems allow automatic selection of different
sensor heads to measure different areas or properties of a sample. As example, different types of optical sensors as well
as tactile sensors can be used with the same machine.
In this paper we describe different principles of optical sensors used in multi sensor coordinate measurement systems as
well as a new approach for tactile measurement with sub micrometer accuracy. A special fiber probe has been developed.
The tip of the fiber probe is formed as a sphere. The lateral position of this sphere is observed by a microscope optics and
can be determined to a fraction of a micrometer. Additionally, a novel optical set-up now even allows the determination
of the z-position of the fiber tip with sub micrometer accuracy.
For this purpose we use an interferometric set-up. The light of laser is coupled into the optical fiber. The light, exiting the
fiber tip is collected by a microscope optics and superposed with a reference wave, generated directly from the laser. The
result is an interferometric signal which is recorded by the camera and processed by a computer. With this set-up, the zdisplacement
of the fiber sphere can be measured with an accuracy of a fraction of the used laser wavelength.
A 3D numerical study of pinhole diffraction in visible-light point diffraction interferometry
Show abstract
The projection objectives，used in modern projection lithography, such as deep-ultraviolet lithography (DUVL), or
extreme-ultraviolet lithography (EUVL), desire very high-quality optics. It has placed stringent requirements on the
accuracy of the interferometers used for optical metrology. Point diffraction interferometry, which generates a spherical
reference wave front by pinhole diffraction, has been developed to meet this need. In order to estimate the measurement
accuracy, several scalar wave diffraction methods have been used when the diameter of the pinhole is much larger than
the wavelength. However, while the diameter keeps decreasing, ultimately to the order of the wavelength, it is obviously
not appropriate to calculate in the same way. So, a three-dimensional (3-D) electromagnetic field simulation, based on
Finite Element Method (FEM), is set up to study the propagation of the visible- light, 632.8 nm wavelength, through sub-
1000nm diameter pinholes in a chromium membrane. Deviations have been calculated to predict the accuracy, between
perfect sphere and the wave front, diffracted by a series of pinholes with different diameters.
The design and comparison of transmission turbidity detection and scattering turbidimetry detection
Dong He,
Lianqing Zhu
Show abstract
The light absorbed degree of color solution is related to solution concentration, level thickness and incident wavelength.
The blood coagulation analyzer designed with optical heterometry method is lower priced ,and the complete absorbancy
curve can be got ,so it has some advantages for excluded the impact of random errors and further studies. The designed
acquisition circuit are composed of the led, silicon photocell, I/V converter, amplifying circuit, it input the detected
voltage variation signal data to acquisition Card of A/D acquisition terminal then the data is processed by PC. According
to the normalized design ideas, both projective method and scattering method are used in a test. Due to the Acquisition
Card stable performance, high resolution and free from external influence ,so it can collect high-precision data for further
data-processing .In order to improve the test accuracy, collecting data before and after reaction to eliminate ambient light
interference. Verify the feasibility of this design by test APPT, and compare the two methods.
In-line monitoring of thermal deformation and surface topography of flip chip substrates
Show abstract
In the manufacturing process of flip chip packaging, the IC chip would be subjected to a temperature increase to roughly
150°C. With the rise of temperature, the chip is induced to a series of deformations which lead to possible malfunction of
the IC unit. Therefore, the investigation of in-line thermal deformation of the flip chip substrates in chip packaging
process is important. In this study the thermal deformation and surface profile of flip chip substrates under thermal stress
are simultaneously measured with a system composed of digital image correlation (DIC) and projection fringe
techniques. DIC technique is implemented to measure the in-plane deformation distribution and strain tendencies of flip
chip substrates while projection fringe method is used to grab the out-of-plane deformation and surface profile of the
substrates. Experimental results show that the warpage effect of the substrates is obvious when subjected to thermal
loading. Since the measurement system is very easy to be implemented, this combination of DIC and projection fringe
technologies maybe one of the most possible techniques for the growing need of in-line thermal deformation monitoring
in the production line of flip-chip packaging.
The simulation and experimental analysis of the MFL for cracks inspection in pipelines under mechanics-magnetic coupling
Show abstract
Since the magnetic flux leakage (MFL) for cracks inspection in pipelines can be influenced by stress concentration, it is
very difficult to characterize and size the crack or crack-like defects. Thus, the theory model of magnetization and
permeability under mechanics-magnetic coupling was derived by thermodynamic equation firstly, and the effects of the
applied stress on magnetization and permeability were analyzed theoretically. The finite element method (FEM) under
mechanics-magnetic coupling was studied, and the relationship of the crack’s MFL and loaded stresses were simulated
and studied using the 3D FEM. And the simulation results were verified by experiments with the help of material testing
system (MTS). The simulation and experimental results demonstrate that the experimental results are basically consistent
with simulation results, and the MFL density caused by cracks decreases with the applied stress increasing gradually.
Therefore, the higher sensitivity sensors should be employed in the MFL measurement for pipeline cracks and the testing
data should be compensated while quantitative interpretation.
Design and realization of measuring system for pneumatic solenoid valve based on high speed data acquisition
Yi Lu,
Wei-jun Fan,
Zai Lao,
et al.
Show abstract
Pneumatic high-speed solenoid valve is a very important comment for automation control system. With the rapid
development of industry its quality requirements are getting higher and higher. The traditional method is manual
measurement or semi-automatic measurement, and comprehensive evaluation of solenoid valve parameters is lacked. To
solve the problem of measuring solenoid valve at present, the PC controlled experimental tester for solenoid valve based
on high speed data acquisition was built up. It can measure these parameters: dynamic characteristic, sealing
performance, the minimum pilot pressure test, fatigue life test. To verify the system accuracy, a dynamic simulation
model of solenid valve based on Matlab/Simulink was designed. This model can provide a basis for the design of
solenoid valve. The solenoid valve of type QVT307 was measured on the experimental device, and the applications
software was programmed by VC++, which had the function of A/D high-speed data acquisition. The results show that
characteristic parameters of the solenoid valve can be judged well by this system. Data acquisition rate can be up to
0.1ms, and the pressure resolution is 0.1Kpa.
Hardware-software partitioning for the design of system on chip by neural network optimization method
Show abstract
In the design procedure of system on chip (SoC), it is needed to make use of hardware-software co-design technique
owing to the great complexity of SoC. One of main steps in hardware-software co-design is how to carry out the
partitioning of a system into hardware and software components. The efficient approaches for hardware-software
partitioning can achieve good system performance, which is superior to the techniques that use software only or use
hardware only. In this paper, a method based on neural networks is presented for the hardware-software partitioning of
system on chip. The discrete Hopfield neural networks corresponding to the problem of hardware-software partitioning is
built, the states of neural neurons are able to represent whether the required components or functionalities are to be
implemented in hardware or software. An algorithm based on the principle of simulated annealing is designed, which can
be used to compute the minimal energy states of neural networks, therefore the optimal partitioning schemes are obtained.
The experimental results show that the hardware-software partitioning method proposed in this paper can obtain the near
optimal partitioning for a lot of example circuits.
Use evolutionary strategies to design the structure of network-on-chip
Show abstract
The network-on-chip (NoC) is a scalable and flexible infrastructure for the design of system on chip (SoC). The
performance of data communication in a network-on-chip depends heavily on the topology structure and routing
algorithm. The communication bandwidth requirements of a network-on-chip can be reduced when the irregular
topology structures are designed for specific application systems. In this paper, a new method is presented for designing
the structure of network-on-chip, the method is based on the evolutionary strategies. First of all, the initial topology
structures are produced by the random approach. Secondly, the topology structures are coded as individuals, and the
topology structure corresponding to an individual is strongly connected, that is there is a path between every pair of
nodes. The feasible topology structures can be obtained by applying the operations in the evolutionary strategies to the
population being consisting of individuals. The experimental results demonstrate that the method proposed in this paper
can obtain the feasible topology structure of network-on-chip.
Precise thermal control of CCD assembly of space optical remote sensor
Show abstract
One of the most significant requirements driving CCD assemblies design is the operating temperature. In order to avoid
unaccepted dark current, CCD need operate between 7°C and 15°C and temperature gradient across the focal plane
should be not greater than 1.0°C. These requirements must be achieved by combining active and passive measures. This
paper focuses on the precise thermal control design, analysis and test. Because CCD assemblies include focal electronics
and movable precise focalizing parts, thermal control must utilize the integrated method to achieve compatible design.
Largely using standard and well-proven technologies, this paper also points out some special techniques used. Based on
finite difference method and transient energy equations, thermal model of CCD assemblies were built utilizing thermal
software and solved for extreme cases. To validate the design, thermal balance test has been done. Analysis and test
results have shown that CCD temperature can be controlled between 7.2°C and 13.5°C and temperature gradient was less
than 0.5°C. These jobs could give some guidance and reference for the precise thermal control of CCD assembly of other
space optical remote-sensor.
Optical visualization of acoustic wave propagating along the wedge
tip
Show abstract
Machine tool blades exhibit typical wedge-shaped tips where defects are very likely to exist and call for non-destructive
characterization. In order to detect the defect on the wedge tip, the interaction of wedge wave with defect characteristic
needs to be investigated. Antisymmetric flexural (ASF) modes are wedge waves (WW) with their particle motion
antisymmetric about the mid-plane bisecting and energy tightly confined near the wedge tip. A quantitative laser
ultrasound visualization (QLUV) system which employs a pulsed laser to scan over the interested area then detected with
a piezoelectric transducer. With the aid of reciprocal theorem, dynamic behaviors of ASF modes encountering a defect
can be reconstructed. In this research, the QLUV system is used to evaluate the characteristic of WWs and the
phenomenon of defect effect including mode conversion and the scattering intensity. With the QLUVS behaviors of ASF
modes interacting with a wedge-tip-crack are characterized in a quantitative way. More complex behaviors for higherorder
ASF interacting with cracks are under investigation.
Research on the automatic laser navigation system of the tunnel boring machine
Show abstract
By establishing relevant coordinates of the Automatic Laser Navigation System, the basic principle of the system which
accesses the TBM three-dimensional reference point and yawing angle by mathematical transformation between TBM,
target prism and earth coordinate systems is discussed deeply in details. According to the way of rigid body descriptions
of its posture, TBM attitude parameters measurement and data acquisition methods are proposed, and measures to
improve the accuracy of the Laser Navigation System are summarized.
Measurement and investigation into air source heat pump exergy
Show abstract
This study applies the second law of thermodynamics to analyze the irreversibility of air source heat pump systems. By
using both T type thermocouple wires to measure the inlet and outlet temperatures of key components in the system and
using pressure transmitters to measure the high and low pressure of the experiment systems, we collect data and use two
control volume(CV) models to calculate the generative volume and irreversibility of entropy for each system
component. According to the experiment results for both CV models (the CV of the refrigerant section and the CV of
the whole control), the heat exchanger is found to have the largest irreversibility. The irreversibility error of the
condenser is 4.6% and the irreversibility error of the evaporator is up to 21%. By applying the results of this study it is
possible to improve the function of air source heat pump systems through improving the heat exchanger, achieving both
cost and energy savings.
A glass tube micro-stylus probe for surface form metrology
Show abstract
This paper presents a micro-stylus probe, which is composed of a precision glass micro-ball and a shaft made by a glass
tube. The diameter of the micro-ball was 50 μm. The tip angle of the glass-tube shaft was approximately 10 degrees.
Strength test shows that the tolerance of glass tube micro-stylus against external forces is 90 mN. To reduce the stick-slip
phenomena, a micro-tapping probe employing the glass tube micro-stylus and a PZT actuator was demonstrated. The
micro-stylus probe was mounted to an air-bearing displacement sensor for scanning surface form metrology.
Experimental results showed that the micro-tapping probe was effective for reducing the influence of the stick-slip
phenomena.
Full-field chromatic confocal surface profilometry employing DMD correspondence for minimizing lateral cross talks
Show abstract
In the research, full-field chromatic confocal surface profilometry employing digital micro-mirror device (DMD) for
spatial correspondence is proposed to minimize lateral cross talks between individual detection sensors. Although fullfield
chromatic confocal profilometry is capable of enhancing measurement efficiency by completely removing timeconsuming
vertical scanning operation, its vertical measurement resolution and accuracy are still severely affected by the
potential sensor cross talk problem. To overcome this critical bottleneck, a DMD-based chromatic confocal method is
developed by employing a specially-designed objective for chromatic light dispersion and a DMD for lateral pixel
correspondence and scanning. Using the chromatic objective, the incident light is dispersed according to a pre-designed
detection range from a few micrometers to several millimeters and a full-field reflected light is captured by a three-chip
color camera for multi color detection. Using this method, the full width half maximum (FWHM) of the depth response
curve can be significantly sharpened, thus improving the vertical measurement resolution and repeatability of the depth
detection. From our preliminary experimental evaluation, it is verified that the ±3σ repeatability of the height
measurement can be kept within 2% of the overall measurement range.
Design of a linear-rotary micro-stage
Show abstract
This paper presents a linear-rotary micro-stage that can generate motions along and about the Z-axis using piezoelectric
elements (PZTs). The small stroke of a PZT is extended by repeating the PZT motions based on a mechanism of impact
friction drive. The friction drive mechanism has a simple driving unit, which only consists of a PZT element and a
friction element. The moving element of the stage, which is a steel cylinder, is supported and actuated by a driving unit,
which consists of two PZTs and a friction component made by permanent magnet. The magnetic force is employed for
holding the moving element and stabilizing the driving condition. The dimension of the stage is 7.0 mm × 8.8 mm × 7.5
mm. The moving ranges of the stage are about 5.0 mm in the Z-direction and 360 degrees in the θz-direction,
respectively. The maximum moving speeds are approximately 30 mm/s and 84 rpm in the two directions, respectively.
Separation and reconstruction of high pressure water-jet reflective sound signal based on ICA
Show abstract
The impact of high pressure water-jet on the different materials target will produce different reflective mixed sound. In
order to reconstruct the reflective sound signals distribution on the linear detecting line accurately and to separate the
environment noise effectively, the mixed sound signals acquired by linear mike array were processed by ICA. The basic
principle of ICA and algorithm of FASTICA were described in detail. The emulation experiment was designed. The
environment noise signal was simulated by using band-limited white noise and the reflective sound signal was simulated
by using pulse signal. The reflective sound signal attenuation produced by the different distance transmission was
simulated by weighting the sound signal with different contingencies. The mixed sound signals acquired by linear mike
array were synthesized by using the above simulated signals and were whitened and separated by ICA. The final results
verified that the environment noise separation and the reconstruction of the detecting-line sound distribution can be
realized effectively.
Research on a novel method of real-time detection and dynamic calibration for angular displacement sensor
Show abstract
Aiming to improve the measurement accuracy of angular displacement sensor effectively and greatly reduce the
production costs under an ordinary machining accuracy. A new method of error correction called harmonic calibration
based on the closure property of circle was presented. Using this method, real-time and dynamic error separation and
correction can be realized when error curve of angular displacement sensor is uncertain. In addition, a method of
“spatial sampling” is presented to solve the problem of asynchrony for dynamic sampling. Furthermore, another method
which adopts software assist to accomplish adaptive filter is presented to eliminate the influence of random error in the
dynamic measurement. As a result a system of full-automatic real-time detection and dynamic calibration for angular
displacement sensor with intelligent functions was developed. Experiment results prove that the accuracy of time grating
can reach up to ±1” in this way. This effective dynamic method can provide a qualitative and quantitative analysis for
calibration of angular displacement sensor.
A new measuring method for motion accuracy of 3-axis NC equipments based on composite trajectory of circle and non-circle
Show abstract
Geometric motion error measurement has been considered as an important task for accuracy enhancement and quality
assurance of NC machine tools and CMMs. In consideration of the disadvantages of traditional measuring methods，a
new measuring method for motion accuracy of 3-axis NC equipments based on composite trajectory including circle and
non-circle(straight line and/or polygonal line) is proposed. The principles and techniques of the new measuring method
are discussed in detail. 8 feasible measuring strategies based on different measuring groupings are summarized and
optimized. The experiment of the most preferable strategy is carried out on the 3-axis CNC vertical machining center
Cincinnati 750 Arrow by using cross grid encoder. The whole measuring time of 21 error components of the new method
is cut down to 1–2 h because of easy installation, adjustment, operation and the characteristics of non-contact
measurement. Result shows that the new method is suitable for ‘on machine’ measurement and has good prospects of
wide application.
Dynamic force calibration by laser interferometer
Show abstract
Traditional we use the standard accelerometer to calibrate the dynamic force. The standard accelerometer was
calibrated by vibration standard machine. However, the calibration condition is not as the use condition. So we need to
develop a dynamic force calibration method, which was the same condition as used. This paper describes a new method
of dynamic force calibration. Now we measure the acceleration by a laser Interferometer. Traceability for force is
realized via the measurement of acceleration with laser-Doppler-interferometers and the determination of the dropping
masses. This paper introduces the structure and the working principle of the equipment, performance parameters and the
uncertainty evaluation. This paper also compares the data between the accelerometer and laser-Doppler-interferometer.
Imaging spectrograph for fast LED optical properties measurement
Show abstract
Due to the booming in LED applications, fast and accurate inspection tools to monitor LED quality is necessary. In this
paper, we propose two new methods to measure LED optical properties by using imaging spectrograph. Imaging-type
spectrograph with high spatial and spectral resolutions is designed for LED wafer measurement. Fiber-type spectrograph
with multi-head structure is designed for LED backlight and LED light-bar measurement. Optical properties of LED
include chromaticity and luminous intensity, which are measured by following CIE recommendations. The performance
of imaging spectrograph is evaluated to meet industrial requirements for LED measurement.
Research on dynamic error correction method for NC rotary table based on time grating sensor
Show abstract
In order to apply original absolute time grating sensor to closed loop numerical control system, a forecasting angle
displacement method with time series analysis theory is proposed. In this way, an absolute time grating sensor can be
transformed to an incremental time grating. In addition, a discrete standard quantity interpolation method is present to
reduce dynamic forecast error. In this way, forecast error of the last measurement period will be corrected in the next
measurement period. Therefore, cumulative errors can be eliminated. The experiment results prove that dynamic errors
can be controlled within ±3″ with error correction method.
Analysis of microfluidic flow driven by electrokinetic and pressure forces
Chien-Hsin Chen
Show abstract
This work presents an analysis of microfluidic flow introduced by mixed electrokinetic force and pressure gradient.
Analytical solutions are presented for the case of constant surface heat flux, taking the Joule heating effect into account.
The present problem is governed by two scale ratios and the dimensionless source term. The two important ratios are the
length scale ratio ε (the ratio of Debye length to the tube radius R) and the velocity scale ratio Γ (the ratio of the pressuredriven
velocity scale for Poiseuille flow to Helmholtz-Smoluchowski velocity for electroosmotic flow). For mixed
electroosmotic and pressure-driven flow, the resulting velocity profile is the superimposed effect of both electroosmotic
and Poiseuille flow phenomena. It is found that the velocity profile decreases as ε increases and the normalized
temperature profiles across the tube increases monotonously form the core to the wall. The maximum dimensionless
temperature is observed at the wall and the wall temperature increases with increasing Joule heating. Also, the
temperature is increased with increasing the value of ε . The fully developed Nusselt number takes the maximum value
at the limiting case of ε → 0 , and then decreases with increasing ε . Moreover, the Nusselt number decreases
with Γ and then goes asymptotically to the limit of Poiseuille flow as Γ → ∞ , where the flow is dominated by the
pressure force.
Calibration of the constants of high precision range-finder using unequal weight separation method
Huan Bao,
Dongming Zhao,
Ziao Fu,
et al.
Show abstract
The additive constant C and multiplication constant R are two of the most important parameters for the corrections that
are made to the measurements of electronic range-finder. The two parameters have direct influence on the correctness of
measurements, and therefore are requisite for electronic range-finder calibration. In the paper firstly the operations of
invar ruler contrast method as well as the determination of additive constant using simple analytical method were
presented. Then based on the additive constant and the characteristics of the multiplication constant, the Unequal Weight
Separation Method (UWSM) for separative calibration of the additive constant and the multiplication constant was put
forward. The accuracy of UWSM was also analyzed, which was verified by processing data from multiple range-finders.
Analysis showed that UWSM is easy to implement, reliable, and causes low intensity of workload, which is favorable to
objectively assess the performance of high-precision of electronic range-finders.
Gravity anomaly interpolation based on genetic algorithm improved back-propagation neural network
Dongming Zhao,
Huan Bao,
Qingbin Wang,
et al.
Show abstract
The principal weakness of the traditional BP Neural Network (BP NN) is that it cannot avoid local minimum, while the
Genetic Algorithm (GA) has the ability of globally optimum-searching, and therefore a new approach, GA-improved BP
NN method, was presented for gravity anomaly interpolation. Firstly GA was used for optimizing the initial link weights
as well as the threshold of the layers of the traditional BP NN, and then the training was completed using BP method.
Numerical experiments were performed for gravity anomaly interpolation based on field measurements using BP NN
and GA-improved BP NN respectively. Through comparison among the results, we found that not only the convergence
rate and generalization ability of GA improved BP NN are higher than those of the traditional BP NN, but also the
efficiency of the GA improved BP algorithm is more satisfactory.
The study of double flank micro gear roll testing
Show abstract
The recent fast development of multifunctional portable electronic devices results in the obvious requirement of micro
mechanical components. Due to the popular application of the micro actuators and the micro gearboxes, micro gears
become the frequently used micro mechanical component in a small device such as small intelligent robots or dental
surgical devices. Metal Industries Research & Development Centre (MIRDC) has successfully developed a small speed
reducer that comprises several micro planetary gear trains. The module of this micro planetary gear train is 0.12mm.
Since all gears are small, no commercial instrument is available for inspection. How to evaluate the manufacturing
quality of micro gears becomes an important issue. This study focuses on the double flank gear rolling test and a
specialized apparatus is built referring to the testing requirements in the international standards. The center distance
variation during the rolling test is recorded and two indices, the total radial composite deviation and the maximum
tooth-to-tooth radial composite deviation, are calculated to evaluate the accuracy grade of the micro gears. Experimental
results show that the accuracy of the micro gear made by the cold forging process conforms to grade 7 defined in the ISO
1328-2 while grade 2 is achieved if the JGMA 116-02 is specified.
Automatic railway wheelset inspection system by using ultrasonic technique
Show abstract
As one of the most important transportation, the safety of railway is paid much attention to. The quality of wheel should
be checked periodically, especially in high-speed application. Normally, Non Destructive Testing (NDT), such as
ultrasonic inspection method, is applied on wheels to find the defect. A stationary automatic railway wheelset inspection
system by using ultrasonic technique is described in this paper. The phased array ultrasonic technique and wheel defect
inspection method is described in detail. Specially designed line is installed for wheelset transportation. Wheelset lifting
and rotating device is used for wheelset loading, unloading and rotating. A steel frame with complicated mechanical
structure and ultrasonic devices are designed for wheelset defect detecting. System ultrasonic performance, system
working flow, system control networking, data processing and results displaying are also described in the paper. Now,
the system is installed in Chinese EMU maintenance center for disassembled wheelset inspection and the safety of
wheels is well protected.
Measurement of microchannels inside transparent substrate based on confocal microscopy
Show abstract
In this paper an efficient method is proposed to measure the geometric dimensions of a microchannel bonded by a
transparent top plate by employing the techniques of quick vertical scan of featured surfaces, detailed multi-layer
sampling of depth response curves (DRC), and measurement of the refractive index of transparent top plate. The featured
surfaces with profile fluctuation in the micro scale are scanned with high vertical resolution. The absolute height of each
surface is determined by the peak point of the corresponding DRC. Since the DRCs are only sampled in the central area
the processing speed is acceptable even with a large scanning length. The results of the measured depth should be
corrected by the refractive index. Only in the same material does the focal point move at the same speed during the
scanning motion. In this study an inverse measurement scheme is proposed to calculate the refractive index of a
transparent plate without prior calibration. Any measurable steps on the sample surface can be used as the sampling area.
By scanning the same area from both sides different sectional profiles can be extracted. The ratio of the different steps is
the refractive index.
A controlled-force laser interference profilometer
Bo Yang,
Suping Chang,
Tiebang Xie,
et al.
Show abstract
This paper presents a controlled-force laser interference surface measuring system, which can achieve high-precision
surface profile measurements in a large range. The key technology of the system is the controlled-force laser interference
displacement sensor based on Michelson interference principle. The system operates in micro-force by the voice coil
motor (VCM) which alters the measuring contact force in real time and reduces the scratches caused by the stylus tip on
the surfaces of the tested samples. The position of the stylus can also be changed, which avoids the damage of the system
when the stylus scans across high steps or deep grooves. The optical and mechanical principles of the displacement
sensor, the realization method of controllable measuring force and photoelectric signal processing are discussed in this
paper. Additionally, this paper introduces the two-dimensional stage used for high precision scanner, and presents
primitive experimental results.
Non-uniform interpolation and re-sampling for tactile scanning measurement
Xiaojun Liu,
Yanghui Hei,
Jianjun Wang,
et al.
Show abstract
In large range surface measurement by tactile scanning method, nonlinearity problems due to the change of vertical
projection height of the stylus and that of the horizontal projection length of the stylus arm are unavoidable during
scanning measurement, which will result in nonlinearity of the transducer in vertical direction and also non-uniform
sampling interval in horizontal direction, and hence measurement and evaluation error for surface measurement. To
solve this problem, current methods are mainly based on modeling and least square fitting, in which a polynomial model
with many coefficients to be determined to relate sampling data to practical coordination of measurement points is given,
then by least square fitting the coefficients are obtained based on a group of data from a standard sphere measurement, so
that the polynomial model is obtained explicitly and sampling data can be compensated for accurate measurement. A
problem in this method is the incompleteness of the model, and the standard sphere is a specific standard sphere with
given diameter, which doesn’t necessarily include all possible cases with different surface curvatures. In this paper, the
nonlinearity mechanism is analyzed, an explicit model based on the mechanism is built, the nonlinearity effect is
investigated, and non-uniform interpolation for profile reconstruction and resampling are attempted to improve the
analysis and evaluation accuracy. Finally computational and experimental testing are conducted to verify the
improvement.
Development and assessment of a fiber-optic liquid level sensor with long-period fiber grating and Shewhart control charts
Show abstract
This paper presents the development and assessment of a liquid level sensor using long-period fiber grating (LPFG)
technology and Shewhart control charts. The 22-mm LPFGs were fabricated with the point-by-point CO2 laser
engraving method. This sensor was designed in such a way that it could be moved up and down with a position
controller. The experimental section covered LPFG position sensing test, liquid level detection capacity and reliability
measurements, and sensing resolution evaluation. LPFG position sensing test was studied and confirmed by the
resonance wavelength shifts which were significantly generated when 75% of the LPFG was immersed in water. There
were ten groups of different liquid level capacity testing and each group underwent ten repeated measurements. Based
on Shewhart control charts including an X-bar chart, s chart, and R chart, the results showed all measurands within the
upper and lower control limits. This sensor was reliable and the liquid level could be measured at least 1000 mm. The
transmission loss versus the percent of immersion of the LPFG sensor for water and green tea was used to study the
sensing resolution. The findings show the LPFG-based liquid sensor had at least 1000-mm level measurement capacity
and about 2-mm resolution.
An embedded image processing and feedback compensation for the vibration-resistance system using white light interferometer
Show abstract
The active interferometer has been approved as an effective architecture to increase the precision of surface profile
measurement by detecting the environmental vibration and then stabilized by a piezoelectric transducer. The
performance of such system can improve the accuracy within nano-meters. Most of the active interferometers have being
implemented on the PC based platform because it is easy to be setup and modulized, However, the latency of image
grabbing processing, mathematic algorithm and I/O trigger delay is around 10~15ms. Moreover, the latency is varying if
different PCs are used.
In this study, an embedded real-time controller based on the ADI Blackfin BF561 DSP microprocessor was developed to
improve the performance of a vibration-resistance system using white-light interferometer. The purpose of this
embedded control system is to detect the vibration and compensate it for White Light Interferometer when processing
stepping photograph grabbing for surface profile measurement.
A customized embedded control system with a 600 MHz high performance microprocessor, Camera Link interface,
DAC circuit and UART command port has been developed. A complete command set has also been defined to
communicate with PC based interferometer user interface for close-loop control. The latency has been reduced from tens
of millimeters to 250 μs as tested for all the procedures from CCD trigger, image processing, to PZT control signal
output. It has been proved to be useful of fixing the latency between phase detecting and compensation output. With this
advantage, the response of the interferometer can accelerated so that the vibration-resistance is improved and the overall
accuracy can be in the range of a few nano-meters.
A component based software framework for vision measurement
Lingsong He,
Lei Bei
Show abstract
In vision measurement applications, it is usually used to achieve an optimal result by combing different processing
steps and algorithms .This paper proposes a component based software framework for vision measurement. First,
commonly used processing algorithms of vision measurement are encapsulated into components that contained in a
components library. The component which is designed to have its own properties also provides I/O interfaces for extern
calls. Second, a software bus is proposed which can plug components and assemble them to form a vision measurement
application. Besides components managing and data line linking, the software bus also provides service of message
distribution, which is used to drive all the plugged components working properly. Third, a XML based script language is
proposed to record the plugging and assembling process of a vision measurement application, which can be used to
rebuild the vision measurement application later. At last, based on this framework, an application of landmark extraction
that applied in camera calibration is introduced to show how it works.
A new and effective 3D measurement system for micro solder bump
Show abstract
Fringe projection with phase shifting technology has been widely used for micro solder bump inspection. Spherical
solder bump is referred to as specular-dominant, mirror-like, metallic reflection. Specifically, the saturated area is placed
on the top of the bump surface, it makes the height profile distort and could not interpret reliable height data. In this
paper, we propose a new three-dimensional measurement system with circular motion that can easily evaluate
relationship between projection angle and reflectance of the bump, tackling these issues. The proposed system without
any additional polarizer and cameras, makes saturated pixels far away from the center of the solder surface so that most
saturated pixels are placed on the out of the measuring target area by increasing projection angle. The accurate height
profile and high repeatability are obtained as reliable measurement results with the optimal projection angle, and it shows
high potential for practical micro bump inspection in field.
A novel implementation of homodyne time interval analysis method for primary vibration calibration
Show abstract
In this paper, the shortcomings and their causes of the conventional homodyne time interval analysis (TIA) method is described with respect to its software algorithm and hardware implementation, based on which a simplified TIA method is proposed with the help of virtual instrument technology. Equipped with an ordinary Michelson interferometer and dual channel synchronous data acquisition card, the primary vibration calibration system using the simplified method can perform measurements of complex sensitivity of accelerometers accurately, meeting the uncertainty requirements laid down in pertaining ISO standard. The validity and accuracy of the simplified TIA method is verified by simulation and comparison experiments with its performance analyzed. This simplified method is recommended to apply in national metrology institute of developing countries and industrial primary vibration calibration labs for its simplified algorithm and low requirements on hardware.
Fractal analysis of motor imagery recognition in the BCI research
Show abstract
A fractal approach is employed for the brain motor imagery recognition and applied to brain computer interface (BCI).
The fractal dimension is used as feature extraction and SVM (Support Vector Machine) as feature classifier for on-line
BCI applications. The modified Inverse Random Midpoint Displacement (mIRMD) is adopted to calculate the fractal
dimensions of EEG signals. The fractal dimensions can effectively reflect the complexity of EEG signals, and are related
to the motor imagery tasks. Further, the SVM is employed as the classifier to combine with fractal dimension for
motor-imagery recognition and use mutual information to show the difference between two classes. The results are
compared with those in the BCI 2003 competition and it shows that our method has better classification accuracy and
mutual information (MI).
Vibration errors in phase-shifting interferometer with absolute testing
Show abstract
Requirements for the measurement resolution in the sub-nanometer range have become quite common. Result of the
testing contain the reference surface errors and test surface errors in the high-accuracy Phase shifting interferometer
(PSI) which test the relative phase between the two surface. The test accuracy can be achieved by removing the error of
reference surface. In this case, one of body of so-called absolute tests must be used which can test the systematic errors,
including the reference surface, of the instrument to be used to improve the test accuracy. Unexpected mechanical
vibrations can significantly degrade the otherwise high accuracy of phase-shifting interferometer. The data acquisition is
sensitivity to vibration with a function of the frequency. The influence of the longitudinal vibration is analyzed in this
paper. We use Zernike polynomials to generate 3 plats. Then the Matlab is used to simulate the 4 frames phase-shift
algorithms and absolute testing algorithms. An experiment used the Zygo interferometer to prove the arithmetic and we
can see the vibration errors in the testing.
Frictional properties of lubrication greases with the addition of nickel nanoparticles in pneumatic cylinder
Ho Chang,
Chou-Wei Lan,
Jia-Bin Guo
Show abstract
This paper studies the influence of addition of 100 nm diameter nickel nano-particles on the friction properties of
synthetic grease (Li base, VG100) in pneumatic cylinder. The friction force test of pneumatic cylinder equipment
measures the frictional force between seal and cylinder bore in pneumatic cylinders. The lubricants with addition of
nickel nano-particles were used for lubricating the contact interface between seal and cylinder bore. The friction force
test equipment employ a load cell force sensor to measure the friction force between seals and cylinder bores. Results
obtained from experimental tests are compared to determine the friction force between seals and cylinder bore in
pneumatic cylinders. The study leads to the conclusion that the addition of nickel nano-particles to synthetic grease
results in a decrease in friction force between seals and cylinder bores in pneumatic cylinder. This tribological behavior
is closely related to the deposition of nano-particles on the rubbing surfaces
A new model and improvement on test methods of the readout noise in the CCD camera
Show abstract
In this paper, a comprehensive model is developed for the scientific CCD camera readout noise. The readout noise can
significantly reduce the ability of weak signal detection and ultimately affects the performance of an image processing
approach to some extent. The different readout noise sources in scientific CCD camera are well documented, however,
there has been little paper on the development of an all-sided readout noise model about the scientific CCD camera.
Based on the proposed model, this paper presents a new test method that is present for choosing the standard section by
defining criteria of optimality. The proposed method can get the more accurate readout noise than the test method used
by experiment and analysis. Besides, the proposed method is fast and simple and therefore can be fitted in the analysis of
data and post-image processing, which have very important application in analysis of the CCD camera other
performance indicators.
Design and characterization of a chip defect inspection system during bonding process based on linear CCD imager
Ming-Fu Chen,
Po-Hsuan Huang,
Yung-Hsiang Chen,
et al.
Show abstract
Defect occures for a few of chips during manufacture. If defect size is greater than the criterion of impacting chip
quality, these unqualified chips have to be removed. Presently used chip defect inspection system is designed basing on
frame CCD imagers. Some drawbacks exist for this system, such as pause image acquisition, mosaic processing for
acquired frame images per chip before inspection, etc. Therefore, the efficiency and accuracy of defect inspection
degrade seriously. So chip defect is now still inspected manually on production lines.
This work presents the design and characterization of an inspection system to detect chip defects with high performance
based on a linear CCD imager. Defects with size of greater than 15μm shall be detected, and moving speed of inspected
chips shall be greater than 0.6m/sec. Thus, proposed system has the characteristics of having the resolution of 5μm and
10μm for optical lens and CCD imager respectively, image line rate of greater than 120 kHz. Chip edge is derived to
achieve the high correctness of inspection. A novel algorithm to inspect defects size is also developed here.
Proposed system has advantages of such as non-pause image acquisition, unnecessary image mosaic, etc. And
inspection efficiency and accuracy will be substantially improved. Moreover, system can be operated automatically
during bonding process to inspect chips quality.
Algorithm of white-light interferometry for reconstruction of profile
Show abstract
An algorithm is proposed to process the interference signals of white-light interferometer in order to obtain the surface
height/depth profile of a sample by using the maximum envelope method. Via a low-pass filter, the DC signal of the
interference signal is obtained, and then a preprocessed signal which is the difference of the interference signal and its
DC one is calculated. After that, the envelope of the preprocessed signal is obtained by using Hilbert transform, and then
the height is estimated by the following peak detector. Based on this algorithm, the surface morphology of the sample is
reconstructed. In our experiment, a step of 75 nm was set for a PZT motor, the scanning span in z-axis was 10.5 μm, and
a 50-fold Mirau interferometer was used. In addition, a polynomial fitting can be used further for the peak detection of
this envelope to improve the accuracy. Moreover, a spatial low-pass filter can be utilized to smooth the height profile.
Deployment precision measurement modeling of a deployable space telescope based on tape springs
Show abstract
Tape springs have many advantages to develop spaced-based deployable systems because of their simple structures, light
weights, high stiffness, and the abilities of self-deploy and self-lock. Their applications in deployable space structures
make the spaced-based systems fulfill the requirements of light weight and compact launching volume. A new kind of
deployable space telescope under research uses tape springs as the support structure of secondary mirror. Before launch,
the support structure of secondary mirror is folded, and deployed when on orbit. In order to achieve near diffraction
limited imaging quality, the deployment precision must reach the level consistent with the optical compensation system.
We designed an accurate measuring system based on position sensitive detectors (PSDs) to measure the deployment
precision. The measuring system includes 3 laser diodes, 3 two-dimensional PSDs around the primary mirror of the
deployable telescope, and 3 small mirrors around the secondary mirror. The equations linking the PSD readings and the
six-degree-of-freedom displacement of the secondary mirror were deduced. With these equations, the deployment errors
can be resolved.
Dynamic characteristic analysis of the constrained beams
Show abstract
A procedure is developed in this investigation to study the propagation of impact-induced axial waves in the constrained
beams that undergo large rigid body displacements. The solution of the wave equations is obtained using the Fourier
method. Kinematic conditions which describe mechanical joints in the system are formulated using a set of nonlinear
algebraic constraint equations that are introduced to the dynamic formulation using the vector of Lagrange multipliers.
The initial conditions which represent the jump discontinuity in the elastic coordinates as the result of impact are
predicted using the generalized impulse momentum equations that involve the coefficient of restitution as well as the
Jacobian matrix of the kinematic constraints. The convergence of the series solutions presented in this paper is examined
and the analytical and numerical results are found to be consistent with the solutions obtained by the use of the classical
theory of elasticity in the case of plastic impact. The cases in which without and with the gravity are also examined and it
is shown that the generalized impulse momentum equations can be used with confidence to study the propagation of
elastic waves in applications related to multibody dynamic systems.
Parameters measurement of wheel set using three-dimensional profile reconstruction
Show abstract
The defects of wheel sets seriously affect the train operation safety which of problem to be solved. A method of
detecting the wheel sets defect is investigated through the three-dimension profile. The three-dimension profile
reconstruction of wheel sets is realized by combining two-dimension CCD imaging with line laser and encoder. The
theoretical derivation of detecting principle is established, and the factors of influencing the measurement accuracy are
analyzed. An algorithm is set to processing measurement data, the main parameters of wheel set are obtained, including
flange thickness, flange height, vertical wear (QR) and tread wear. The results of simulations and field experiments show
that the proposed method can detect the faults on the wheel correctly, and satisfy the requirements of high efficient and
accurate.
Wedge angle measurement of transparent objects by adopting transmitted differential interference contrast technique
Sheng-Kang Yu,
Wei-Lun Chen,
Ting-Kun Liu,
et al.
Show abstract
Effects of the wedge prism angle on the accuracy of angle measurement using the transmitted phase shifting differential
interference contrast (DIC) technique were studied in this paper. The optical model was constructed and serious of
simulations were conducted to fulfill this study. Various prism angles were tested in the simulations. As expected,
results indicated that the reconstructed wedge angle measured by the DIC system was incorrect because the light
propagation became irregular. Regardless of the profile reconstruction result, the original optical path differences of
light were highly correlated to the prism angle. Therefore, modification is needed to calculate the wedge angle
accurately when the DIC approach is adopted. It is also found that the magnification of the objective lens (correspond to
the numerical aperture and the working distance) have significant effects on the measurement. These results suggest that
modification is needed to calculate the wedge angle accurately when the DIC approach is adopted. This study might
provide some valuable information for adopting the DIC technique when it comes to complex geometry measurement in
the future.
Measuring technology for runout of high-precision master gear
Yong Ma,
Zhifeng Lou,
Jingli Jin,
et al.
Show abstract
High-precision master gear is mainly used as the measuring reference of general-precision gear, check of gear measuring
instrument and so on. However, the present measuring method for its own deviation, such as runout , is still
immature. A new measuring technology for runout of high-precision master gear is developed. The main error sources of
runout measuring system are analyzed, measuring and data processing are aided by computer and compensation method
is introduced. It achieves the requirement of the measuring for master gear accuracy grade 2.
Research on the pattern evaluation in the digital speckle pattern interferometry
Show abstract
Digital Speckle Pattern Interferometry (DSPI) is one of modern optical measurement techniques. It has the advantage of
non-contacting, whole field, high measurement accuracy and without special process of the surface to be measured. With
the development of computer science and electronics, DSPI is used more and more widely. This paper systematically
presents the principle of speckles and measurements by DSPI. Optical measurement system based on DSPI was built for
demonstrate. In order to quantitative determination of the distribution of phase change, several imaging process and
pattern evaluation methods are discussed and compared. Phase shifting techniques and phase pattern filter methods also
were described in detail. In this paper, some experiments results were given, which clearly demonstrate that that the
methods are effective for processing pattern.
Research on automatic defect localization for ultrasonic normal probe detection on railway wheel
Show abstract
Wheel detection is a significant guarantee for ensuring train-running safety. Ultrasonic phased array inspection
technology is popularly applied in railway wheel and axle inspection at present. The objective of our study is to develop
a data processing algorithm which makes use of image processing techniques in order to assist ultrasonic inspection
operators in their difficult task. The research work described in this paper has thus been done with this objective in mind
and it concerns a method that we have developed for automatic detection of defects. This method is based on region
connection and region growing and it allows to position defects in the wheel under inspection by automatic analysis of
the ultrasonic data.
Nonlinearity error correction of constant voltage power supply
Show abstract
The paper introduces the basic principle of a kind of constant voltage power supply. A output circuit and a sampling
feedback circuit are included in the power supply. There is a big problem between the two circuits, which is obvious
nonlinearity error. Some simulation test is done in order to reduce the nonlinearity error. Two methods are presented
according to the simulation result. One method is to add a self-adjusting circuit in the sampling feedback circuit, which
can reduce the nonlinearity error through hardware. The other method is to add a special program in the soft so that the
control signal is adjusted to be nonlinear according to the feedback signal, which can reduce the nonlinearity error
through soft. The adjusting process is done repeatedly. The experiments show that the output of the constant voltage
power supply ranges from 25 volts to 150 volts. Its error is reduced from original 43 volts to 0.6 volt and its hysteresis is
improved greatly.
Rapid measurement of micro discharging gap
Show abstract
There is micro discharging gap to be measured between negative electrode and positive electrode in precise micro
electrical discharging machining. The state of the discharging gap is complex and variable. There are many factors which
have effects on the state. Furthermore, practical application wants rapid measurement to meet the satisfaction of pulse
response. Normal measurement method is not suitable to obtain the information of the micro gap. The paper introduces
an important relationship between the voltage of discharging pulse and the size of discharging gap. Then, several typical
measurement methods and their interrelated basic circuits are presented, such as gap average voltage measurement
method, gap peak voltage measurement method and electrical discharging sensing method, etc. The measurement
circuits are designed correspondingly. Pulse response test under different conditions are carried out. Results show that
the measurement circuits can detect the variance of gap size respectively and rapidly. The measurement methods are
effective.
Influence of the concentration measurement of carbon monoxide with temperature
Show abstract
In order to figure out the concentration of carbon monoxide, by measuring the second and third harmonics of the
absorption spectrum line, this paper obtained results which indicate that this method can be applied to industry field.
Tunable semiconductor laser of 1.58um can be used, and its wavelength is a nice window of communication in long
wavelength band of fiber. The measurement optical paths can well be integrated with fiber and passive component in
fiber system and it is already applied to industry field. Moreover, the 1.58um spectrum line is an absorption peak of
carbon monoxide and around the spectrum line, there is a good transmission window in the background gas of
atmosphere. It is very well to measure carbon monoxide concentration. Through measuring peaks of the first and second
harmonic or the second and fourth harmonic of absorption spectrum lines of carbon monoxide with tunable diode laser
absorption spectroscopy (TDLAS) technique, the carbon monoxide concentration can accurately be calculated by
composition algebra. This paper focuses on the study that the absorption coefficient changes with temperature. As the
absorption coefficient of different temperature changes, the parameters of concentration measurement will change. This
is a very complicated process.
Applying Kalman filter on optical measurement of atmospheric compositions (Withdrawal Notice)
Wenjun Li
Show abstract
This paper was presented at the SPIE conference indicated above and has been withdrawn from publication at the
request of the author.
Zernike moments features for shape-based gait recognition
Show abstract
The paper proposes a new spatio-temporal gait representation, called cycles gait Zernike moments (CGZM), to
characterize human walking properties for individual recognition. Firstly, Zernike moments as shape descriptors are used
to characterize gait silhouette shape. Secondly, we generate CGZM from Zernike moments of silhouette sequences.
Finally, the phase and magnitude coefficientsof CGZM are utilized to perform classification by the modified Hausdorff
distance (MHD) classifier. Experimental results show that the proposed approach have an encouraging recognition
performance.
The non-contact precision measurement and noise reduction method for liquid volume metrology
Show abstract
Liquid volume is one important metrology method for commercial transaction in international trade, and vertical tank is
used as main metrology tool. One non-contact optical measurement system was raised by using laser scanning method.
The coordinates of vertical tank shell were acquired by phase-shift ranging method and angular measurement, and the set
of coordinates is named as data cloud. The measurement errors of distance and angle are 2mm and 2" respectively.
Wavelet was applied to noise reduction and curve feature extraction for data cloud. Iterative method was used to deduce
the radius at each course height. One 1000m3 vertical tank used as test object, comparison experiment was carried out
with strap method (international arbitral standard). The experimental results show that the noise due to tank shell surface
characteristics and laser scanning devices could be filtered satisfactorily, and the local curve features of tank shell were
described correctly.
The investigation of mold life for glass thermal imprint
L. K. Chen,
Y. M. Hung,
C. K. Sung
Show abstract
Thermal imprint provides a stable and rapid approach in the fabrication of precision V-groove structures.
This paper presents a theoretical and experimental study focusing on the estimation of mold life based on
both the formation and wear mechanisms. In the experiment, BK-7 was used as the substrate, and the
mold with V-groove patterns was fabricated with glassy carbon. The formation of V-groove
microstructures on BK-7 glass substrate was implemented by a lab made thermal imprint equipment,
while the precision of imprinted pattern was measured by an optical measurement system. Additionally,
the micro-scale friction and wear theories were adopted to estimate the mold life. Finally, the prediction
model of mold life can be estimated by the relative friction and wear theories and measurement data,
which enable us to efficiently optimize the glass thermal imprint process.
Investigation of the thermally structural denaturation of bovine serum albumin by a home-made optical heterodyne polarimeter
Show abstract
Bovine serum albumin (BSA) solutions (2.5 %, PH 7.2) under heat treatment can result in structural changes. Some of
the α-helices are transformed at 67°C to random coils resulting in an increased rotation angle. With subsequent heating,
the transformed random coils may once again transform to non-native β-sheets and restore the optical rotation angle.
These two states are all reversible. However, when the heating temperature goes up to 69°C the denatured BSA starts to
transform into a rigid network and becomes an irreversible state. The reversible and irreversible temperatures of BSA
were determined and discussed.
Evaluation method for one-dimensional assembly yield based on Taguchi orthogonal experiment
Show abstract
Evaluation method for one-dimensional assembly yield is presented based on Taguchi orthogonal experiment. Firstly,
according to Taguchi parameter design criteria, component loop sizes are taken for factors of Taguchi orthogonal
experiment, each factor is divided into three levels. After approriate orthogonal experiment table is selected, orthogonal
experiment is operated. Then the mean and standard deviation of close loop size are solved, which are used to obtain
assembly yield. The influence on assembly yield of each factor is analyzed by using extreme value method and the
results are validated by using Monte Carlo simulation. Finally, a gear components assembly is provided to illustrate the
effectiveness of the presented method .It has a guiding significance for machanical assembly design.
Study on the dynamic performance of a novel buck-boost matrix converter based on double-loop control strategy
Qing Li,
Qi Chen
Show abstract
The dynamic performance of a novel Buck-Boost matrix converter (BBMC) based on double-loop control strategy is put
forward in this paper. The fundamental principle of BBMC has been elaborated and the method of the double-loop
control strategy has been built with Matlab, and then the dynamic performances of BBMC based on the double-loop
control strategy are discussed. The results show that the output voltage and frequency can be almost constant with the
BBMC and double-loop control strategy despite of the changeable input voltage and frequency. Moreover, a high-quality
sine output wave with low harmonic distortion can be directly obtained without filtering. So it can be drawn that the
BBMC based on the double-loop control strategy has perfectly dynamic performance and practical importance to the
engineering.
Improved wavelet de-noising method of rail vibration signal for wheel tread detection
Show abstract
The irregularities of wheel tread can be detected by processing acceleration vibration signal of railway. Various kinds of
noise from different sources such as wheel-rail resonance, bad weather and artificial reasons are the key factors
influencing detection accuracy. A method which uses wavelet threshold de-noising is investigated to reduce noise in the
detection signal, and an improved signal processing algorithm based on it has been established. The results of
simulations and field experiments show that the proposed method can increase signal-to-noise ratio (SNR) of the rail
vibration signal effectively, and improve the detection accuracy.
ESPI solution for defect detection in crystalline photovoltaic cells
Show abstract
The yield of photovoltaic (PV) cells is often reduced by micro-defects in crystalline silicon substrates during fabrication.
Common optical inspection for a thin crack in such a large silicon photovoltaic cell is extremely time-consuming and
fails in efficiency. This study developed a method of using electronic speckle pattern interferometry (ESPI) for rapidly
testing for cracks in an entire field of PV cells. Thermally induced flexural cell deformation was measured by optical
configuration for ESPI measurement of out-of-plane deformations. Experimental results indicate that the speckle patterns
correlating with thermal deformation of cell enable simultaneous estimation of crack size and location in both single- and
poly-crystalline PV cells. This nondestructive detection method has potential applications in PV cell sorting.
Development of a 3D touch trigger probe using micro spherical stylus machining by micro-EDM for micro-CMM
Show abstract
This study develops a low-cost three-dimensional touch trigger probe for micro-CMM using micro spherical stylus
machining by micro-EDM. The tip ball of the stylus, with a diameter smaller than 100 μm, is made by a micro electro
discharge machine with the method of wire electro discharge grinding (WEDG). The current study uses tungsten
carbide (WC) as the material for the stylus. Experimental results show that, the tip ball roundness could amount to 2
μm. Since the tip ball is not easily observable by naked eyes, we designed a micro imaging system to observe the
probing in real time. This system is created with modified commercial webcam and microscope.
The general design of the touch trigger probe is combined the stylus and suspension structure. When the stylus touches
workpiece, it can be determined the time of probe trigger by measuring the motion of suspension structure. The stylus
machined by micro-EDM was very fragile and the stylus handle of the tip ball was very thin. Therefore, the stylus handle
bends easily that would result in the large measurement error or stylus break when the stylus touched workpiece. In this
study we designed a measuring probe using a small chuck and an electrical circuit to measure the probe trigger. When
the stylus touches the workpiece, the parallel circuit will switch on immediately and pick up the voltage variation of the
resistor. Because the transistor always turns ON, it can avoid the problems of excessive energy and electrical noise.
Design of life testboard of manual slack adjuster
Zai Luo,
Guofeng Qiu,
Min Lin,
et al.
Show abstract
In order to solve the problem of realization of the manual slack adjuster’s life test system, this paper introduces the
hardware system design and software programming to control the movement of manual slack adjuster intelligently, so as
to record and judge single manual slack adjuster’s life. The paper firstly introduces the manual adjuster’s structure, work
theory and the structure expression of its failure. Then, based on the work theory, it is designed that the test system which
mainly consists of hardware system and software system. The hardware system is composed of computer, PLC
(Programmable Logic Controller), electric control system, pneumatic system, sensor system, the adjuster to be measured
and so on. The software system consists of control software and display software. Control software is designed by using
ladder diagram for programming in CX-Programmer 7.3 environment. Meanwhile, display software which is based on
MCGS (Monitor and Control Generated System) software is designed with a reasonable and convenient interface. We
calculate uncertainty in life testing of the manual slack adjuster to analyze the experimental results. The experimental
results show that the system runs stably and measures accurately. Consequently, it meets the design requirements well.
Development of a lightweight portable optical measurement system for the print-through phenomenon of fiber-reinforced plastics
Show abstract
Due to the volumetric shrinkage of the resin and the induced residual stress during the curing process, the
reflection on the gel-coating layer surface will be imperfect if twists and wrinkles exist on the gel-coating surface. This
phenomenon is denoted as print-through phenomenon (PTP). Currently, the detection of PTP for most of the yacht
industry using the composite materials is performed mainly by visual inspection, and its quality is needed to be
quantified to determine their grades. Therefore, there is a need to develop a lightweight portable optical measurement
system that can be applied quickly to inspect different levels of PTP for the fiber-reinforced plastics (FRP) of the yacht
body. The measurement system was developed based on the scattering principle of a reflected laser fringe projected on
to the workpiece surface. Two indexes, namely the profile peak-valley height and wave-height of the Fast-Fourier
Transform based on the centerline of the extracted image profile, were proposed to quantify the PTP of a test specimen.
The mean line width of the extracted image was applied to evaluate the surface roughness of the test specimen, based on
the scattering theorem. A set of software programmed with Borland C++ Builder language was developed to calculate
the proposed indexes and the mean line width. The developed measurement system has been taken to some yacht
factories to do the on-site measurements. The measurement results were, in general, consistent with the surface
conditions of the polished surfaces.
Measurement and deposition of nanometer-scale Cu dot using an atomic force microscope with a nanopipette probe in liquid condition
Show abstract
In this study, we developed novel techniques of nanometer-scale measurement and deposition using an atomic force
microscope (AFM) with a nanopipette in liquid condition. The nanopipette, filled with CuSO4 electrolyte solution, was
employed as the AFM probe. Observation and deposition of nanometer-scale Cu dots were carried out using the
nanopipette probe. In order to avoid drying of the nanopipette solution and clogging of the probe-edge aperture, Cu dots
were deposited and measured in liquid condition. As for the measurement of the surface, the nanopipette probe was
glued on a tuning fork quartz crystal resonator (TF-QCR) to detect a probe oscillation and vertically oscillated to use a
method of frequency modulation in tapping-mode AFM. With regard to the deposition of nanometer-scale Cu dot, an
electrode wire inside the electrolyte-filled nanopipette and conductive surface of Au coated glass slide were employed as
the anode and cathode, respectively. By utilizing the probe-surface distance control during the deposition, nanometerscale
Cu dot were successfully deposited on Au surface without the diffusion. Then, the deposited dots were observed by
using the nanopipette probe. This technique of the local deposition in the liquid would be applicable for various fields
such as fabrication of micro/nanometer-scale devices and arrangement of biological samples.
A system for the measurement of thermal deformation of mechanical parts
Zai Luo,
Ningxia Liu,
Quan Luo,
et al.
Show abstract
A high-accuracy system to measure the thermal deformation of mechanical parts is proposed, which combines
two-frequency laser interferometer, constant temperature cabinet and position finding part. The whole system include
four parts. The two-frequency laser interferometer is used for measuring the displacement, and the constant temperature
cabinet controls the temperature of the mechanical parts. Each part may bring in some uncertainty. To different
workpieces, the ultimate principle is actually very similar although measurement methods may be a little difference.
Various errors related to system are analyzed by processing the measured original displacement data using mathematics
analysis and methods of error analysis. Error analysis and experimental studies are presented to approve this system
which has high measurement accuracy and high accuracy of temperature control. Taking diameter measured about
cylindrical work pieces for instance, the accuracy of the system is analyzed. The result of thermal deformation in steady
temperature field is proved. The results also show that there is a good repeatability with deviation of 0.5μm in the
system when the same diametric thermal deformation of a Φ 50mm cylindrical piece in the same temperature variation
is measured for 5 times.
Non-invasive measurement of micro-area skin impedance in vivo
Show abstract
Volume measurement of interstitial fluid transdermally extracted is important in continuous glucose monitoring
instrument. The volume of transdermally extracted interstitial fluid could be determined by a skin permeability
coefficient. If the skin impedance which is the indicator of skin permeability coefficient can be accurately measured, the
volume of interstitial fluid can be calculated based on the relationship between the indicator and the skin permeability
coefficient. The possibility of using the skin impedance to indicate the skin permeability coefficient is investigated. A
correlation model between the skin impedance and the skin permeability coefficient is developed. A novel non-invasive
method for in vivo, real-time, and accurate measurement of skin impedance within a micro skin area is brought forward.
The proposed measurement method is based on the theory that organisms saliva and interstitial fluid are equipotential.
An electrode is put on the surface of a micro skin area and another one is put in the mouth to be fully contacted with
saliva of an animal in the experiments. The electrode in mouth is used to replace the implantable subcutaneous electrode
for non-invasive measurement of skin impedance in vivo. A biologically compatible AC current with amplitude of
100mv and frequency of 10Hz is applied to stimulate the micro skin area by the two electrodes. And then the voltage and
current between the two electrodes are measured to calculate the skin impedance within a micro skin area. The
measurement results by electrode in mouth are compared with the results by subcutaneous electrode in animal
experiments and they are consistent so the proposed measurement method is verified well. The effect of moisture and
pressure for the measurement is also studied in the paper.
Development and calibration of a compact self-sensing atomic force microscope head for micro-nano characterization
Show abstract
A compact self-sensing atomic force microscope (AFM) head is developed for the micro-nano dimensional
measurement. This AFM head works in tapping mode equipped with a commercial self-sensing probe. This kind of
probe can benefit not only from the tuning fork's stable resonant frequency and high quality factor but also from the
silicon cantilever's reasonable spring constant. The head is convenient to operate by its simplicity of structure, since it
does not need any optical detector to measure the bending of the cantilever. The compact structure makes the head ease
to combine with other measuring methods. According to the probe’s characteristics, a method is proposed to quickly
calculate the cantilever’s resonance amplitude through measuring its electro-mechanical coupling factor. An experiment
system is established based on the nano-measuring machine (NMM) as a high precision positioning stage. Using this
system, the approach/retract test is carried out for calibrating the head. The tests can be traced to the meter definition by
interferometers in NMM. Experimental results show that the non-linearity error of this AFM head is smaller than 1%, the
sensitivity reaches 0.47nm/mV and the measurement stroke is several hundreds of nanometers.
Development of a dual-axis optoelectronic precision level
Show abstract
This paper presents the design principle and applications of a innovative dual-axis optoelectronic level. A commercially
available DVD pickup head is adopted as the angle sensor in association with the double-layer pendulum mechanism for
dual-axis swings. A mass-damping system is analyzed to model the mechanical dynamics. Measured angles of both axes
are processed by a microprocessor and displayed on a LCD or exported to an external PC. Compared with a triple-beam
laser angular interferometer, the error of the dual-axis optoelectronic level is better than ±0.5 arc-seconds in the
measuring range of ±20 arc-seconds, and the settling time is within 0.5 sec. Two experimental results show the
consistency with a Renishaw interfereometer and its practical use in industry.
Contouring error compensation on a micro coordinate measuring machine
Show abstract
In recent years, three-dimensional measurements of nano-technology researches have received a great attention in the
world. Based on the high accuracy demand, the error compensation of measurement machine is very important. In this
study, a high precision Micro-CMM (coordinate measuring machine) has been developed which is composed of a coplanar
stage for reducing the Abbe´ error in the vertical direction, the linear diffraction grating interferometer (LDGI) as
the position feedback sensor in nanometer resolution, and ultrasonic motors for position control. This paper presents the
error compensation strategy including "Home accuracy" and "Position accuracy" in both axes. For the home error
compensation, we utilize a commercial DVD pick-up head and its S-curve principle to accurately search the origin of
each axis. For the positioning error compensation, the absolute positions relative to the home are calibrated by laser
interferometer and the error budget table is stored for feed forward error compensation. Contouring error can thus be
compensated if both the compensation of both X and Y positioning errors are applied. Experiments show the contouring
accuracy can be controlled to within 50nm after compensation.
Integrated gray-level gradient method for 3D velocity fields extraction of sprays in in-line digital holography
Show abstract
In this study, integrated gray-level gradient method, locating the best focal plane, is applied to extract the 3D velocity
fields of sprays in in-line digital holography. This method consists of a conventional edge-sharpness [Es] method and a
new method, namely, overall-sharpness [Os] method which is an efficient supplement of the former. The respective
scopes of application of above criterions were discussed by using numerical simulation holograms of particles. And then,
The integrated gray-level gradient method is proved to be an effective tool for the determination of focal plane by using
the calibration target. Finally, the synchronization system is designed and assembled to record double exposure spray
holograms in a short time interval. Using the integrated gray-level gradient method and some image processing
techniques, the 3D coordinates of droplets are easily obtained which can be used to evaluate the 3D velocity fields of
sprays. It proves that the integrated gray-level gradient method is well applied to measure the characteristics of sprays in
in-line digital holography.
Reconstruction of the hologram generated by spherical wave
Show abstract
In this paper, a diverging spherical beam goes through the object field and the part of the beam diffracted by the objects
and arriving at the recording surface is considered the object beam, while the beam arriving without any distortion is
considered the reference beam. The superposition of the two beams creates an interference pattern on the CCD sensor.
The magnification image can be obtained by two methods based on convolution method and Fresnel method. The
relationship between the quality of holograms and some parameters was obtained by comparing the images of
reconstruction at different distances. The convolution method is better than the Fresnel method. The results show that the
digital holography using spherical wave can work well.
Measurement and research on the appearance of tongue board based on modification to discuss centrifugal fan air performance
Show abstract
This paper presents a reduced fan noise method, with increased fan-benefit analysis of various performances. The
experimental approach adopts changes in the outlet in the form of two fans (flat tongue and a V-Type tongue plate) in order
to measure the noise under the two forms of value and volume of supply air fan, shaft power consumption, operating current,
and static pressure. The results showed that the tongue plate and the V-plane tongue plate noise between the value of the
measurement location of 6.7 in the tongue plate in the plane below the noise level is about V-tongue plate 1 ~ 1.5dB (A). Air
flow rate testing showed that the flat plate and the V-Type tongue plate between the tongue plate V-Type flow rate value, the
measurement location of 3.4 in the tongue plate in the plane was more than the V-Type flow rate tongue plate 5 to 5.5%.
Shaft power testing of measurement model 3, and measurement model 4, showed that the tongue plate in the plane V-tongue
plate was more than 8%, 5%. The measurement models 3 and 4 and 5 showed more than the V-Type plane tongue plate 1%,
2.7%, and 2.6%. The measurement models 6 and 8 showed that, the flat tongue plate is less than the V-tongue plate of 2.9%
and 2.3%. Static pressure testing showed that the flat tongue plate in particular measurement models (3,4,8,9), the static
value of V-tongue plate than the 11.1% higher, respectively, 9%, 4.3%, and 3.7%. The results summarized above suggest that,
in the specific measurement points, when parallel to the tongue plate the V-tongue board has better performance.
Accurate and efficient identification of cable natural frequencies for cable tension monitoring by vibration frequency method
Show abstract
Vibration frequency method is widely used to measure cable tension of cable-stayed bridges at present. Accurate and
efficient identification of cable natural frequencies is one of critical factors in cable tension monitoring. However, it is
difficult to efficiently identify accurate natural frequencies in practice. Based on the theory of vibration frequency
method, this paper first gives an analysis on how the data sampling parameters affect the accuracy of natural frequencies
identification, so as to propose an optimization method of setting sampling parameters. Then, according to the vibration
mode of a cable, a new approach, spectrum multiplication, is put forward to help to efficiently identify these frequencies
by improving SNR of the vibration spectrum. Field experiments of cable tension monitoring are done at a cable-stayed
bridge. The results indicate that measurement accuracy and efficiency are both improved with the optimized sampling
parameters and the spectrum multiplication.
PZT local linearity and image sampling strategy for white-light vertical scanning measurement
Show abstract
White-light vertical scanning technique has been used for surface topography measurement because of its characteristics
of non-contact, high-accuracy and large range. In this technique, PZT is usually employed for high resolution vertical
scanning. Due to the nonlinearity and creep characteristics of PZT however, large scanning positioning error is inevitable
if direct interference image sampling without positioning metrology is adopted. Otherwise if positioning metrology is
adopted for every image sampling, measurement efficiency will be reduced greatly. To solve this problem in this paper,
the nonlinearity characteristic of PZT is analyzed and its local linearity is investigated, and based on the local linearity a
novel interference image sampling strategy is proposed. In this strategy, the whole scanning range is divided into many
sub-ranges, in which the non-linearity errors are small enough for direct interference image sampling. When white-light
vertical scanning measurement is conducted, in every sub-range, interference images are sampled directly at every
scanning position corresponding to equal driving voltage interval of PZT, while the end points of each sub-range are
measured by a positioning metrology system. Thus based on the local linearity of sub-range, the scanning positioning for
image sampling can have enough accuracy, while less positioning metrology is needed for high measurement efficiency.
Analysis and case study proves the improved scanning positioning accuracy and measurement efficiency through the
novel sampling strategy.
Strain measurement aided assembly for a CFRP hexapod
Show abstract
In order to mount a space optical telescope with long focal length on a spacecraft for an astronomy observation mission,
a carbon fiber reinforced plastic (CFRP) hexapod with titanium alloy brackets was designed and fabricated. Each bracket
has a pair of heads and each head has two orthogonal flexures as virtual pivots without clearance to provide flexure
mounts. Because of no adjustment parts, slight differences among components and roughly assembly would result in
misalignment and asymmetrical stress in the hexapod. The stresses and strains of the CFRP hexapod structure under 1G
gravity load were analyzed with finite element method. In order to monitor the assembly stress and provide regulating
guidance, strain gauges were stuck centrally on the bottom flexures of each bracket. Comparing the measured strains
with the computed values, the low stress assembly of the CFRP hexapod has been accomplished successfully.
Intensity error correction for 3D shape measurement based on phase-shifting method
Show abstract
3D shape measurement based on structured light system is a field of ongoing research for the past two decades. For 3D
shape measurement using commercial projector and digital camera, the nonlinear gamma of the projector and the
nonlinear response of the camera cause the captured fringes having both intensity and phase errors, and result in large
measurement shape error. This paper presents a simple intensity error correction process for the phase-shifting method.
First, a white flat board is projected with sinusoidal fringe patterns, and the intensity data is extracted from the captured
image. The intensity data is fitted to an ideal sine curve. The difference between the captured curve and the fitted sine
curve are used to establish an intensity look-up table (LUT). The LUT is then used to calibrate the intensities of
measured object images for establishing 3D object shapes. Research results show that the measurement quality of the 3D
shapes is significantly improved.
Design and implementation of an early warning system in vehicle for road speed control hump based on DSP and CCD
Show abstract
Road speed control humps have the effect of strengthening transportation safety by preventing traffic accidents.
However, vehicles will produce strong mechanical vibrations when crossing speed control humps at high speed. These
vibrations affect the passenger's comfort and cause machine parts damage. Early warning systems in vehicles for road
speed control humps were designed based on DSP and CCD sensors. The system uses a CCD camera to take the picture
of the road speed control humps. The image information is processed and recognised by DSP. Then the related voice
and image information is given quickly and accurately after the system processes. This information will remind the
driver to prepare for slowing down in good time, it makes them safe and comfortable to pass over the road speed control
hump.TMS320DM642DSP early warning system in vehicles was illustrated from three aspects of the image collection
module, the image discernment module and the early warning export module. TMS320C6x soft develop flow was
introduced in this paper. The system has strong practicality, rapid response and well directed-viewing.
Surface warpage measurement of diamond grid disk by shadow Moiré method
Terry Yuan-Fang Chen,
Jian-Shiang Chen
Show abstract
Diamond grid disk dresser is frequently employed to remove the accumulated debris lest the polishing surface glazes. The surface
warpage of diamond grid disk must be small enough to assure the flatness of polished wafers during chemical mechanical
planarization process. In this study, phase-shifted shadow moiré method was employed to measure the surface warpage of diamond
grid disks. To eliminate erroneous bright or black spots caused by the diamond grids, a novel method is proposed by selecting proper
threshold values from the addition of four phase-shifted images, and from the grey-level difference between the addition of phases 0
and π images and the addition of phases π/2 and 3π/2 images. Test of the proposed method on real specimens show that the erroneous
bright and black spots can be effectively identified and patched. Thereafter the phase can be unwrapped successfully to obtain the
surface profile and thus the warpage of specimens.
Application of autoregressive distributed lag model to thermal error compensation of machine tools
Show abstract
Since Thermal error in precision CNC machine tools cannot be ignored, it is essential to construct a simple and effective
thermal error compensation mathematical model. In this paper, three modeling methods are introduced in detail. The first
is multiple linear regression model; the second is congruence model, which combines multiple linear regression model
with AR model of its residual error; and the third is autoregressive distributed lag model(ADL), which is compared and
analyzed. Multiple linear regression analysis is used most commonly in thermal error compensation, since it is a simple
and quick modeling method. But thermal error is nonlinear and interactive, so it is difficult to model a precise least
squares model of thermal error. The congruence model and autoregressive distributed lag model belong to time series
analysis method which has the advantage of establishing a precise mathematical model. The distinctions between the two
models are that: the congruence model divides the parameter into two parts to estimate them respectively, but
autoregressive distributed lag model estimates parameter uniformly, so congruence model is less accurate than
autoregressive distributed lag model in modeling. This paper, based upon an actual example, concludes that
autoregressive distributed lag model for thermal error of precision CNC machine tools is a good way to improve
modeling accuracy.
In-process and post-process measurements of drill wear for control of the drilling process
Tien-I Liu,
George Liu,
Zhiyu Gao
Show abstract
Optical inspection was used in this research for the post-process measurements of drill wear. A precision toolmakers’
microscope was used. Indirect index, cutting force, is used for in-process drill wear measurements. Using in-process
measurements to estimate the drill wear for control purpose can decrease the operation cost and enhance the product
quality and safety. The challenge is to correlate the in-process cutting force measurements with the post-process optical
inspection of drill wear.
To find the most important feature, the energy principle was used in this research. It is necessary to select only the
cutting force feature which shows the highest sensitivity to drill wear. The best feature selected is the peak of torque in
the drilling process.
Neuro-fuzzy systems were used for correlation purposes. The Adaptive-Network-Based Fuzzy Inference System
(ANFIS) can construct fuzzy rules with membership functions to generate an input-output pair. A 1x6 ANFIS
architecture with product of sigmoid membership functions can in-process measure the drill wear with an error as low as
0.15%. This is extremely important for control of the drilling process. Furthermore, the measurement of drill wear was
performed under different drilling conditions. This shows that ANFIS has the capability of generalization.
Nonlinear analysis and dynamic compensation of stylus scanning measurement with wide range
Show abstract
Surface topography is an important geometrical feature of a workpiece that influences its quality and functions such as
friction, wearing, lubrication and sealing. Precision measurement of surface topography is fundamental for product
quality characterizing and assurance.
Stylus scanning technique is a widely used method for surface topography measurement, and it is also regarded as the
international standard method for 2-D surface characterizing. Usually surface topography, including primary profile,
waviness and roughness, can be measured precisely and efficiently by this method. However, by stylus scanning method
to measure curved surface topography, the nonlinear error is unavoidable because of the difference of horizontal position
of the actual measured point from given sampling point and the nonlinear transformation process from vertical
displacement of the stylus tip to angle displacement of the stylus arm, and the error increases with the increasing of
measuring range.
In this paper, a wide range stylus scanning measurement system based on cylindrical grating interference principle is
constructed, the originations of the nonlinear error are analyzed, the error model is established and a solution to decrease
the nonlinear error is proposed, through which the error of the collected data is dynamically compensated.
CAIP system for vision-based on-machine measurement
Show abstract
Computer-Aided Inspection Planning (CAIP) is an important module of modern dimensional measuring instruments,
utilizing the CAIP for machined parts inspection is an important indication of the level of automation and intelligence.
Aiming at the characteristic of visual inspection, it develops a CAIP system for vision-based On-Machine Measurement
(OMM) based on a CAD development platform whose kernel is Open CASCADE. The working principle of
vision-based OMM system is introduced, and the key technologies of CAIP include inspection information extraction,
sampling strategy, inspection path planning, inspection codes generation, inspection procedure verification, data
post-processor, comparison, and so on. The entire system was verified on a CNC milling machine, and relevant examples
show that the system can accomplish automatic inspection planning task for common parts efficiently.
A study of the tool change timing in turning micro V-grooves roller
Show abstract
The diamond tools have been employed in industry in turning micro V-grooves of mirror surface on a large diameter roller for the fabrication of brightness enhancement film (BEF) required in the backlight unit (BLU) of flat panel display by imprint process. They are expensive consumables and should be retired only when necessary, and hence determination of tool retirement timing is essential. Currently it is achieved by visual inspecting the mould surfaces at the production line. No automatic mechanism is available yet. In addition, the replaced new tools must be aligned with cumbersome procedures before turning can be resumed. An approach to determine if the tool is still useful by machine vision strategy is proposed and implemented. The image of the mould surface under a LED white light source is captured by a CCD camera. The brightness of the surface is obtained by algorithm of color space conversion. A threshold value is established experimentally to determine the acceptable brightness of the roller mould surface. It was found that tools must be replaced when surface of workpiece is not mirror like and its brightness value is less than 240. By using the same setup, the amount of tool shrinkage is determined by an image processing algorithm. This can be used not only as tool tip compensation along turning direction but also as an alignment measures after tool replacement. As a result, the new tool can be accurately positioned and matched with the old tool such that the turning process can be continued successfully.
Vibro-acoustic modulation technique for micro-crack detection in pipeline
Jingpin Jiao,
Lei Zheng,
Guorong Song,
et al.
Show abstract
For the poor sensitivity of traditional ultrasonic technique for micro crack detection, a kind of
nonlinear ultrasonic technique, vibro-acoustic modulation technique, is used for micro crack detection
in pipes. The influence of the frequency and amplitude of vibration on the modulation index (MI) is
experimentally investigated. The experiment results prove that the vibro-acoustic modulation technique
can be used for crack detection in pipes. The modulation index is influenced by the frequency and
amplitude of vibration, therefore it is important to choose the appropriate parameters in order to get
higher sensitivity in crack detection.
A comparison of noise removal by the Fourier and the Haar transformations
Show abstract
This paper compared noise removal using the Fourier series and the Haar wavelet transformations. The results showed
that noise from the measured data can be filtered by neglecting high-order terms of Fourier coefficients. It also showed
that signal denoising can be achieved by Haar wavelet transformation by filtering the noise before inverting the
transformed data back to time domain. A further comparison using a set of data with variation 6.3mV from five
measurements of a sample showed that the variations after denoising can be reduced to 3.8mV by the Fourier series and
to 2.3mV by 3-level Haar wavelet. Both methods can filter noise in signal and keep the predicted curve consistent with
the measured data. The signal becomes smooth if denoised by the Fourier series but the variation of signal, however, can
be reduced more if denoised by the Haar wavelet. Moreover, from the computation complexity viewpoint, signal
denoising by Haar wavelet is much better than that by Fourier series.
Optimization of parameters of photonic nanojet generated by dielectric microsphere for laser nanojet SNOM
Show abstract
A new concept of “photonic nanojet” SNOM is proposed in this paper and the system is based on a dielectric
microsphere which is mounted on a cantilever. The dielectric microsphere works as a superlens to focus the laser energy
into a small volume with subwavelength spatial resolution. The numerical simulation by using Finite Element Method
(FEM) has been done to optimize the parameters of the photonic nanojet of dielectic microsphere for “photonic nanojet”
SNOM. The microspheres with different diameters have been investigated numerically and the results show that bigger
microspheres produce higher intensity “photonic nanojets”. The simulation result on the interaction between a silicon
cylinder and a photonic nanojet reveals that a “hot spot” is formed inside the silicon cylinder and is confined into a small
volume. Therefore a new area on high spatial resolution spectral analyzing for nanostructures is in prospect.
Polarized multi-color in-line digital holographic microscope for high-speed 3D surface profiling
Show abstract
A multi-color in-line digital holographic microscope (DHM) has been developed for high speed profile measurement of
micro-structures. The in-line architecture of the proposed DHM offers a high spatial resolution compared with the
conventional off-axis DHM. The multi-color DHM captures the three color hologram simultaneously in one-shot
recording by using a color CCD sensor and three RGB LED sources. The measurement range without phase ambiguity
of the multi-color DHM is extended up to 5 micrometers compared with the 0.3 micrometer of the conventional single
wavelength DHM technology. The real-time reconstruction rate of 3D profile is estimated around 20fps when using a
100 frame/sec CCD camera and a simple three-step phase shifting algorithm. The high reconstruction rate is important
for the measurement in the shop floor where fast measurement and immunity to the environment disturbance are
demanded. The air turbulence and floor vibration effects are further reduced by the near common-path architecture of
the proposed DHM. A phase stability of better than 5nm is achieved without any need of anti-vibration instrument table
and air turbulence protection cover.
Autonomous navigation vehicle system based on robot vision and multi-sensor fusion
Lihong Wu,
Yingsong Chen,
Zhouping Cui
Show abstract
The architecture of autonomous navigation vehicle based on robot vision and multi-sensor fusion technology is expatiated in this paper. In order to acquire more intelligence and robustness, accurate real-time collection and processing of information are realized by using this technology. The method to achieve robot vision and multi-sensor fusion is discussed in detail. The results simulated in several operating modes show that this intelligent vehicle has better effects in barrier identification and avoidance and path planning. And this can provide higher reliability during vehicle running.
A refraction Doppler measurement method
Tingyu Wang,
Jingbin Hu,
Jiabi Chen,
et al.
Show abstract
Doppler Effect has been applied in many fields, such as astronomy, radar, medical imaging, and flow measurement and so on. Most of the applications are based on the reflected or scattered light beam to measure the velocity, that could not measure the abnormal Doppler effect. We present in this paper an experimental system, which use the refracted light beam and maybe can measure the abnormal Doppler effect. Experiments show that the method is exactitude to measure the Doppler shift, and the experimental results are according with the theoretical calculation.
Pulsed eddy current systems for defect and geometrical profile measurement
Show abstract
Pulsed electromagnetic Non-destructive Evaluation (NDE) techniques can be used for defect detection and stress assessment. Currently there is no single technique which would have the capability to provide a comprehensive picture of these material changes, therefore the fusion of data from a number of different sensors is required for early failure prediction. In contrast to fusion techniques, signal feature separation can be applied for defect as well as lift-off measurement. Eddy current sensors can be applied for displacement (proximity) measurement as well as NDE for defect detection and material characterisation. For displacement measurement, one of research aims is to overcome measurement uncertainties due to material variation and in-homogeneity. After the introduction of pulsed eddy current (PEC) NDE, this work reports the separation of pulsed eddy current responses for surface profile and defect inspection. Experimental studies of pulsed eddy current for defects and surface profile measurement are reported.
Human tracking with thermal omnidirectional vision
Y. Tang,
Y. F. Li,
H. Chen
Show abstract
In this paper, we explore a new tracking system for human tracking in thermal catadioptric omnidirectional vision. Due to very limited features can be adopted in thermal image except for contour information, we proposed to use Histogram of Oriented Gradient (HOG) feature to represent the contour information and employ Support Vector Machine (SVM) to classify the foreground and background. In this paper, there are three novel points. First, the classification posterior probability of SVM will be adopted to relate the observation likelihood of particle filter to guide the particles for tracking purpose instead of neglect in previous tracking method. Second, due to no existing thermal catadioptric omnidirectional vision database available in public, a thermal catadioptric omnidirectional video database and extracted human samples have been established for academic studies. Third, tracking window distribution of particle filter has been adjusted to fit the characteristic of catadioptric omnidirectional vision on account of the size of target in image is varying when the distance between target and omni-sensor changed in world coordinate. In addition, the catadioptric omnidirectional imaging is different with traditional imaging for inherent distortion, so the polar coordinate will be used. The experimental results show that the proposed tracking approach has a stable performance.
Review of the state of the art of whole field optical measurement techniques for strain analysis
Thomas Walz
Show abstract
For many years, optical measurement methods have been moving from research institution laboratories to industrial applications. Compact laser-based systems using the principles of speckle interferometry and easily manageable image correlation systems permit the simple and reliable high-precision characterization of materials and components in many different static and dynamic applications. The full-field, non-contact measurement of contours, deformations and strains has distinct advantages over conventional measurement methods resulting in significantly shorter development and testing times. The option of using full-field characterization also for transient events with a high time resolution opens prospects for many new applications in the future.
High-numerical-aperture focused field measurement system based on a confocal microscopy
Zhehai Zhou,
Qiaofeng Tan
Show abstract
A high-numerical-aperture (NA) focused field measurement system based on a confocal microscopy is presented, and its basic structure and operation theory are introduced in details. In order to evaluate the reliability and efficiency of the measurement system, the focused field intensity distributions of several types of beams, including linearly polarized beams, radially polarized beams, azimuthally polarized beams and radially polarized vortex beams are measured while the NA of the focused objective lens is 0.90, and the Measured results agree with the calculated results. In addition, some methods are also proposed to improve the measurement accuracy at last.
Design of 3D translational motion measurement system based on twin area array CCDs
Kai Wang,
Yong Lv,
Qingrui Yi
Show abstract
The measurement of translational motion is widely applied to many fields such as machine vision, automatic control, etc. A new measurement system of 3-D (three dimensions, X, Y and Z direction) translational motion based on twin area array CCDs is designed. The system consists of stationary part and moving part. The stationary part mainly includes two collimated LED (Light-Emitting Diode) light sources, and the moving part consists of twin area array CCDs (ChargeCoupled Device) which are symmetrically installed on and synchronously moved with the measured object. When the measured object moves, the spots projecting on twin area array CCDs will have corresponding position change, according to the change, the 3-D translational variation of the measured object can be calculated. Due to the measurement principle of translational motion in Y direction works in the same way as in X direction, the experimental system is set up to simulate and measure the 2-D translational motion in X and Z direction. Experimental results show that in comparison with HP5529A dual-frequency laser interferometer system, the measurement accuracy is better than ±1μm. The system has the advantages of high accuracy, non-contact and simple structure.
Displacement measurement based on the Moire fringe
Xiaoying Li
Show abstract
Moire fringe can be used for measuring the displacement of the object. In this paper, Charge Coupled Device (CCD) is used for capturing the numerical moire fringe, substituting for the usual photodetector. The movable grating is labeled by the special figure, which moves in the moire fringe with the movable grating moving. The original position serves as the reference, and the special figure is searched for in the moire fringe by the correlation operation to determine its shift of pixel in the screen, then by the calibration value to calculate the displacement of the measured object. This method does not need to count the shifting number of the moire fringe. However the lateral magnifying power of lens is considered seriously.
Measurement system of tiny angle based on LED
Show abstract
Aiming at uncontrollable long-term spot shift problem, a LED system for measuring tiny angle is designed based on optical auto-collimation principle in this paper. The measuring system transforms the angle variation into the change of spot position on CCD (Charge coupled device) and locates the spot by using multiple-circle fitting method. The system is calibrated by use of photoelectrical autocollimator and actual angle variation is determined according to the calibration value. In the system, two kinds of optical source, LED (Light-emitting diode) and LD (Laser diode), are used. A contrast experiment of stability of the two light sources is carried out. Experimental results show that the proposed measuring system has small spot shift, higher stability and precision.
Research on space-borne optical collimation system
Li-shuang Liu,
Yong Lv,
Xiao-ping Lang,
et al.
Show abstract
In this paper a kind of optical collimation system for monitoring space-borne equipment is introduced. The flare image processing technology in the system is analysed specially. The processing speed is improved by the improved average filtering. According to flare image’s completion, the grayscale gravity technique or the circular fitting technique is adopted respectively, which can not only ensure the measurement precision but also extend the measurement range. The measuring stability is 0.22μm and the precision is better than ±0.5μm when the collimation distance is 1.5m under vacuum conditions by the experiment.
Future of phased array radar systems
Show abstract
This paper spots the light on the future progress of phased array radar systems, presenting two innovative examples on the directions of development. The first example starts with the classic radar range equation to develop the topology of what is called a “Mobile Adaptive Digital Array Radar” (MADAR) system. The second example discusses the possibility to achieve what is called “Entangled Photonic Radar” (EPR) system. The EPR quantum range equation is derived and compared to the classic one to compare the performance. Block diagrams and analysis for both proposed systems are presented.