Design of a two-stage adaptive fuzzy controller

In this paper, a systematic two-stage design method for adaptive fuzzy controllers (TSAFC's) is presented. The proposed control scheme has low computational complexity. Moreover, the exact mathematical model of the plant to be controlled is not required. The fuzzy controller under consideration is based on the proportional-derivative fuzzy control scheme and triangular membership functions. In the design procedure, the domain intervals of the input and output variables are selected with a heuristic approach to minimize the cost function under the constraint of tolerable overshoots in the response curve. A learning scheme is then proposed to automatically adjust the parameters in the fuzzy controller to reduce the error of the system. Simulations are included to demonstrate the effectiveness of the proposed method.