System for linear motor control

摘要

Movable (a head) and stationary (a stator) members are disposed in contiguous relationship. First magnetizable and non-magnetizable zones are alternately disposed on the stator in a particular direction. Second magnetizable and non-magnetizable zones are alternately disposed on the head in the particular direction. The zones on the head and the stator face each other and have substantially equal spacings. First means are associated with the head for producing magnetic fluxes in the magnetizable zones in the head and stator in a particular pattern to obtain incremental relative movements between the head and the stator on a vectorial basis in the particular direction. Second means are associated with the head for compensating for hysteresis effects in the magnetizable zones in the head and stator. The second means may produce magnetic flux of alternating polarity and decaying amplitude near the end of each incremental movement of the head relative to the stator. Means are provided for indicating the position of the head relative to the stator in the particular direction at each instant. Means are included for obtaining the production by the first means of magnetic fluxes at each position to provide corrections in the incremental movement of the head relative to the stator in the particular direction at that position.