Precision positioning and measurement for aerospace systems
Thomas R. Hicks, Sean Staines, Chris M. Shannon · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1992
Positional control of components and steering of beams to high degrees of accuracy is becoming more and more important and highly specified, particularly with the advent of Optical Inter satellite Links. Queensgate have developed piezo-electric actuators which are qualifiable for use in space and can comply with the stringent constraints on mass power and volume, which will move up to lOOm repeatable to less than a nanometre. Drifts have been measured in the region of 5nm0C, and non-linearities are consistently measured in the region of 0.3 to O.4°/o. The capacitance sensing technology used for such stable positioning, can also be deployed separately for monitoring positions of assemblies etc. . Novel methods for the sensors and the processing circuitry have been developed extensively over the past year to produce capacitance sensors which will sense or measure gaps of up to 5O0im with a resolution of less than lnm.