Digital-signal-processor-based multirate PID control of a two-link flexible-joint robot

Multirate control has become an area of active research. Concurrent with the development of multirate strategies, there have been increasing applications of digital signal processors in high speed control. This paper presents the design and implementation of a multirate PID controller for a two-link flexible-joint robot. The controller is implemented using the TI Digital Signal Processor TMS320C30 evaluation module. Two multirate algorithms, namely multirate output PID controller and multirate input PID controller were designed and implemented. The multirate controllers are shown to be superior to the conventional single-rate PID Controller. Comparison is made in terms of maximum overshoot, rise time and steady-state error of the closed-loop system.