Internal Model Principle-based Control for Sinusoidal Disturbance Rejection in Field-Oriented Control

This research presents results of combining the field-oriented control of motors with a more general Internal Model Principle controller rather than the specific case of integral control. The goal is to have a motor that can remove narrow band disturbances without impacting its performance outside of this specific frequency. This research is motivated by eliminating tremors in human limbs. We verify our approach by initially implementing the algorithm in Matlab and then conducting experimental trials in our lab using two brushless DC motors. The first motor (Motor 1) will generate a sinusoidal torque signal on the shaft, while the second motor (Motor 2) will utilize our algorithm to cancel this torque. Both motors are connected by a coupler. When Motor 1 initiates rotation with a sinusoidal torque signal, Motor 2 driven with our algorithm will freeze the motion in Motor 1. Thus, the torque on Motor 2 will match that of Motor 1. We then add additional broadband torque in Motor 1 and show that Motor 2 can still match the sinusoidal torque while ignoring this additional movement. We will investigate the difference between using the encoders from both motors as the driving signal for our control algorithm. Keywords: internal model principle, field-Oriented Control, disturbance rejection, brushless DC motors, tremor signal