Research on Robust Current Control Algorithm for Permanent Magnet Synchronous Motor Based on Extended State Observer

High-performance servo joints are the basis for quadruped robots to have excellent motion performance. The current loop is the innermost loop of the servo system, and its control effect on torque directly determines the control effect of the entire servo system. This paper proposes a robust current control algorithm for permanent magnet synchronous motors (PMSM) based on the extended state observer (ESO) to improve the performance of the current loop. Traditional predictive current control relies more on the accuracy of model parameters. This paper uses ESO to obtain unknown disturbances to reduce the dependence of control effects on model parameters. Simulation and experiments show that predictive current control has more excellent dynamic performance than PI control. After adding the ESO compensation link, the static error and oscillation of current caused by controller model parameter error are effectively eliminated, significantly reducing the dependence on model parameters and improving the robustness of the current loop in the servo system.