In sensorless control systems for permanent magnet synchronous motors (PMSMs), the estimation performance of the observer and the tracking performance of the speed controller are critical. To obtain accurate rotor position information, a sliding mode observer (SMO) incorporating an extended-state-observer-based phase-locked loop is designed to improve flux observation and rotor position estimation accuracy. Additionally, to overcome the limitations of a single control architecture and achieve high-performance tracking control, a robust control method that jointly considers tracking performance and disturbance rejection is proposed. A multi-objective complementary control framework is utilized to integrate PI and H ∞ controllers and thereby design a robust control strategy that enhances both tracking performance and robustness in the speed regulation system. Experimental results demonstrate that the designed observer exhibits superior observation performance and estimation accuracy under medium-to-high rotational speed conditions. The proposed control method effectively mitigates the influence of external disturbances and system parameter variations on motor-speed regulation. The closed-loop system improves dynamic performance and disturbance rejection while maintaining steady-state accuracy. Consequently, high-precision robust tracking control is achieved in a sensorless environment.
Liu et al. (Sat,) studied this question.