Fuzzy Variable Structure Controller for Chattering Reduction

In this paper a method of chattering reduction is described using a fuzzy variable structure controller. A part of the state space around the sliding surface and the origin is represented using linguistic variables. A rule based controller which decides the contribution of equivalent control and attractivity control component in the total control input is designed. Their degrees of contribution are decided based on how far the present stale is from the sliding surface and the origin of the state spate. The performance of the proposed controller is demonstrated for a second order linear time invariant system which has parameter uncertainty. The simulation results show that there is a reduction in chattering and control energy.