Automatic Gain Tuning for Robust PID Control Using Time-Delay Control

Abstract

Auto-tuning of robust PID Control is presented. To this end, we propose the equivalence condition between the modified TDC using sliding mode concept and the PID controller in a discrete-time domain. To realize auto-tuning of the PID control gains, we have synergistically combined the sliding mode concept and adaptive control. The desired error dynamics is described by using sliding mode concept, and the adaptive gain dynamics is proposed using the sliding variable. A leakage term is used for the gain dynamics to cope with the noise effect. The gain automatically increases when the sliding mode error is large, and decreases when sliding mode error is relatively small. The tracking errors of the proposed method are almost identical compared with those of well-tuned constant gains. Consequently, auto-tuning of the gains for the PID controller is realized instead of manual tuning.