Fuzzy Logic based Switching and Tuning Supervisor for a Multi-variable Multiple Controller

This paper presents a novel fuzzy-logic based switching and tuning supervisor for an intelligent multiple-controller framework. The fuzzy logic based supervisor operates at the highest level of the system and makes a switching decision, on the basis of the required performance measure, between two non-linear fixed structure controllers, namely a conventional Proportional-Integral-Derivative (PID) controller, or a PID structure based zero and pole placement controller. The fuzzy supervisor also adaptively tunes the parameters of the controllers. The proposed methodology is used to simultaneously control the throttle and brake systems of a validated nonlinear vehicle model. Sample simulation results are used to demonstrate the effectiveness of the multiple-controller with respect to tracking desired vehicle speed changes and achieving the desired speed of response, whilst penalising excessive control action.