Robust-adaptive linearization with torque ripple minimization for a PMSM driven single link arm

The high performance control of direct drive systems (DDS) requires the consideration of the full system dynamics. In this study, a permanent magnet synchronous motor (PMSM) driven single link arm is considered as an example of a direct drive system. To achieve high performance control, an adaptive linearization scheme is implemented on the system to reduce the effects of the cogging and ripple torque of the motor and to compensate for load variations. To improve the performance of the adaptive linearizing scheme, a robust controller based on sliding mode theory is designed for the outer loop. The experimental results obtained are compared to the performance of pure PD control, sliding mode control and adaptive linearizing control algorithms and a significant improvement is observed in the torque ripple spectrum and the overall performance of the direct drive system with the combined control algorithm.