Robust PID force control of IPMC actuators

This paper discusses a simple robust PID (proportional, integral and derivative) tuning method for force control of ionic polymer-metal composite actuators. The model is represented by a transfer function which consists of an electrical part and an electro-mechanical part. The uncertainty is represented by an interval polynomial set of the closed-loop characteristic equations. Using Kharitonov's theorem, we show that just one Kharitonov polynomial stability is necessary and sufficient for satisfying the robust stability of the system. The PID gain is determined by pole placement of the derived Kharitonov polynomial. Experimental results show the effectiveness of the PID force control achieved by the proposed method.