A modified PI control action with a robust adaptive fuzzy controller applied to DC motor

In this paper, a robust and adaptive fuzzy controller to modify a well-known PI controller in order to improve the system performance is presented. Robustness is concluded showing that the sensitivity function of the output is bounded. Based on this robust adaptive fuzzy controller, several performance measures of the controlled plant, including the rise time, delay time, settling time, and percentage of maximum overshoot is shown to be highly related to the parameters in certain fuzzy rules of the controller. The sensitivity functions of the relative errors in the performance measures is used to derive these relations. A DC motor with a nonlinear friction model is used to illustrate this method.