ELECTROMECHANICAL FEEDBACK DEVICE FOR FINE CONTROL OF A PLATFORM POSITION

摘要

A feedback control system for controlling the position of a platform movably mounted on a datum base, comprising a wire of pre-set length attached to the platform and extending to and connected to a fixed position on said base, spring means connected between said platform and a second fixed position on said base for extending the wire, electro-optical means for detecting changes in position of said platform relative to the base and providing an error signal related to such changes and current generating means for applying a current related to said error signal to the wire to alter its length and thus the position of the platform to control and stabilize its position. The preferred form of electro-optical position detector would be a modified Michelson interferometer and the preferred method of altering the wire length would be by thermal expansion or magnetostriction.