A point-to-point position control method for PMSM drives based on disturbance torque observer and acceleration feedback

Abstract

The controller for point-to-point (PTP) servo motion control is required to exhibit a high dynamic response, minimal position-tracking error, and robust disturbance rejection capabilities. Conventional cascaded position–velocity–current architectures often fall short in PTP applications due to the delay introduced by the velocity loop. To address this issue, a dual-loop position controller is proposed, consisting of an outer position loop and an inner current loop. This controller integrates a disturbance torque observer that leverages position signal measurements to enhance robustness. The observer employs a first-order low-pass filter to mitigate noise and measurement errors in the current and position feedback signals. This control architecture is designed to be straightforward and easy to implement. To enhance the transient response to sudden load disturbances, an acceleration-feedback mechanism is integrated into the observer path to bolster disturbance compensation. Experimental results have demonstrated the efficacy of the proposed scheme. In comparison to conventional dual-loop position–current servos, the proposed approach enhances dynamic performance without compromising response time or position tracking performance.