A mode switching control design for fast position servo systems with permanent magnet synchronous motor

A mode switching control scheme is proposed to achieve fast set-point tracking in motor servo systems. The control scheme incorporates a composite nonlinear feedback (CNF) control law into the framework of proximate time-optimal servomechanisms (PTOS). The CNF control law consists of a linear feedback part for achieving fast response and a nonlinear feedback part for suppressing the overshoot, so as to improve the transient performance in short span positioning, while the PTOS control law is responsible for fast acceleration and deceleration when the tracking error is large. A parameterized MSC controller is designed and the closed-loop stability is analyzed theoretically. The control scheme was then applied to the position-velocity control loop in a permanent magnet synchronous motor servo system. Experimental test has been conducted using the TMS320F2812 DSP. The results verify that the servo system is capable of fast and smooth positioning on a wide range of target locations.