Performance Improvement of Robot Motion Control System Based on Adaptive Notch Filters

The motion quality of the robot is determined by the dynamic response and the static response performance of the internal motors. It is a simple and effective way to analyze the motion quality of the robot by decoupling the robot motion control system into multiple single motor control systems. The robot can obtain the excellent dynamic response performance which is driven by the permanent magnet synchronous motor (PMSM) under direct torque control (DTC) strategy, but there exit large torque ripples and flux linkage ripples caused by the inverter nonlinearity in the control system. These ripples of torque and flux linkage are analyzed and the order of the main harmonics are determined. With the using of the adaptive notch filters (ANF) in the torque and flux linkage branch, the main harmonics in these ripples can be eliminated effectively. Theoretical analysis show that the ANF can reduce the torque ripple and flux linkage greatly and it can also maintain the fast dynamic response of the control system. The superiority is verified through the simulation results.