PMSM Sensorless Control of Manipulator Joints Based on Improved Pulsating High Frequency Signal Injection Method

Aiming to address issues such as poor positioning accuracy in sensorless control of permanent magnet synchronous motors (PMSMs) applied to robotic arms, this paper proposes an improved pulsating high frequency signal injection method. The proposed method replaces the bandpass filter (BPF) and low-pass filter (LPF) in the traditional approach with an adaptive second-order generalized integrator (ASOGI). Furthermore, an enhanced phase-locked loop (PLL) structure is introduced, utilizing a PID phase-locked loop with feedforward compensation instead of the PI phase-locked loop used in the traditional pulsating high frequency injection method. Simulation experiments were conducted using MATLAB/Simulink. In the simulated robotic arm scenario, the proposed method demonstrates advancements in rotor tracking speed, rotor positioning accuracy, rotor speed estimation error, and other aspects, indicating its effectiveness in improving the application of sensorless PMSMs in robotic arm systems.