Design of a fuzzy logic controller as a suction controller

A fuzzy logic controller (FLC) designed as a suction controller is proposed. Firstly, we prove that there exists a switching line in the FLC, and the slope of the switching line is determined by scaling factors. Secondly, a Lyapunov function is selected and sufficient conditions for the fuzzy control system (FCS) to be globally asymptotically stable is determined. Based on the sufficient conditions, a design procedure is suggested to guarantee that the FCS is globally asymptotically stable. Both a nonlinear oscillator and a cart-pole system are simulated to demonstrate the proposed FLC. We show that not only is the FLC similar to sliding mode control (SMC), but also a realizable method for a suction controller is described. In addition, a lemma is introduced to interpret that the rise time of the FCS can be adjusted by the scaling factors. (C) 1997 Elsevier Science B.V.