A new type of adaptive fuzzy PID controller

In general, an adaptive fuzzy PID controller (AF-PIDC) means that the PID parameters are adjusted by fuzzy rules in real-time. In this paper, the controller is functionally divided into three operating units which are the proportional operating unit, the integral operating unit, and the derivative operating unit. The inputs of the controller are composes of two kinds of signals. The main input signal is the weighted system error and the weights are the traditional PID parameters with fixed gains tuned in a traditional way. The auxiliary input signal is produced by a fuzzy logic controller. Since the output of the fuzzy logic controller is changeable, the gain of the controller is adjusted implicitly and adaptively. The simulation results show the validity of the proposed approach.