Device for an accurate control of final positioning and follow-up of a displaceable member with respect to a reference

摘要: A system for positioning a displaceable member with respect to reference conventionally uses servo-mechanism having feedback position sensing and speed loops connected an input of the control path servo. Usually, operates in two successive phases:- coarse phase fine phase. In phase, both are active. Nevertheless, if tends fluctuate, accuracy final may be less than acceptable. according this invention, additional device is provided which, under threshold value output difference sensor, disconnects sensor inserts single remaining loop series correcting networks addition ensuring improved positioning, also ensures accurate follow-up fluctuations reference.