Share Email Print

Proceedings Paper

Recent advancements in passive and active vibration control systems
Author(s): K. Peter Heiland
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

The control of environmental vibration is a prime consideration in designing sensitive electro- optical equipment. Pneumatic isolation systems with low natural frequencies are commonly used to shield the payload from random seismic vibration. In order to further optimize the isolation characteristics, it is desirable to decrease natural frequencies in all translational axes to well below 0.5 Hz, while at the same time achieving maximum damping at resonance. The limitations of conventional systems, however, are such that the lowest natural frequency achievable is 1 Hz. Typical resonance amplification is measured at approximately 10 to 20 dB. The use of low-frequency pneumatic isolators in precision machinery with built-in XY-stages (i.e., microlithography, submicron inspection systems (highlights an additional problem. Low natural frequencies are equivalent to low spring stiffnesses. Inertial forces applied to mass- spring systems with low spring stiffnesses results in large dynamic deflections. This kind of motion has an impact on the stability and settling time of XY-stages mounted on the mass spring system. The positioning controller of the XY-stage must overcome these disturbances which are induced by the reacting mass-spring system. The softer the isolation system, the large the dynamic deflection of the mass-spring system will be. It would be ideal to have a system that would act like a perfectly soft suspension system for all floor induced motion, while simultaneously creating an infinitely stiff system for all payload-induced forces. This can only be accomplished by using servo-control mechanisms with feedback and feed forward capabilities. This technology is introduced and analyzed in the body of this paper.

Paper Details

Date Published: 1 February 1992
PDF: 12 pages
Proc. SPIE 1619, Vibration Control in Microelectronics, Optics, and Metrology, (1 February 1992); doi: 10.1117/12.56821
Show Author Affiliations
K. Peter Heiland, Integrated Dynamics Engineering GmbH (Germany)

Published in SPIE Proceedings Vol. 1619:
Vibration Control in Microelectronics, Optics, and Metrology
Colin G. Gordon, Editor(s)

© SPIE. Terms of Use
Back to Top