The self organising fuzzy controller

Abstract

This paper describes the conceptual development of a self-organising fuzzy PID (SOF-PID) controller and applies it to a nonlinear revolute-joint robot-arm. The SOF acts as an intelligent master controller making small changes to the values of the three PID gains during the system operation, without the need to use the knowledge of an experienced human operator. The step input trajectories were applied to the SOF-PID controller at the setpoint. The same experiments were repeated using the conventional self-organising fuzzy (SOF) controller, the PID controller and the self-tuning controller, subject to the same information supplied at the setpoint. The results of the SOF-PID controller were compared with those of the other three controllers. For the step input the SOF-PID controller produced a smaller steady state error and a negligible overshoot compared to the SOF controller, the PID controller and the self-tuning controller.