Robust designated‐time tracking scheme for brushless direct current motor servo systems with input saturation and disturbances

Abstract This article addresses a key tracking control problem for brushless direct current motor servo system (DCMSS): ensuring specified tracking precision before the designated time for the angle and position of the motor relative to a reference trajectory, even when subjected to input saturation and disturbances, while maintaining the tracking error within a predetermined, time‐dependent constraint during operation. Based on a time‐dependent barrier function defined by the settling time and ultimate tracking precision, we design a robust continuous state‐feedback control by combining a designated‐time disturbance observer with an anti‐windup compensator. Improving upon existing DCMSSs tracking schemes, the proposed strategy drives the error in the tracking falls within a specified zone before the designated time. Additionally, it minimizes excessive overshoot and transient oscillations while assuring the ultimate uniformly boundedness of all signals. At last, two groups of simulations for the typical application of DCMSS (i.e., active steering system) are conducted to demonstrate our method's effectiveness.