Controller Design for Affine Nonlinear System Based on Constructing Optimization T–S Fuzzy Model and Disturbance Reconstruction

Abstract

Affine nonlinear systems are special kinds of nonlinear systems, and they can represent many practical systems. Dealing with affine nonlinear system based on T–S fuzzy model has drawn much attention in the literature recently. In this article, a robust control method is proposed for affine nonlinear system with disturbance based on T–S fuzzy model. First, an optimization T–S fuzzy model is constructed focusing on optimizing the parameters of the weight functions by using differential evolution algorithm. Second, in order to reconstruct the disturbance, an interval observer is designed for the affine nonlinear system, and then a novelty disturbance reconstruction method based on the interval observer is developed. The disturbance reconstruction value can asymptotically approach the actual disturbance value, and furthermore, it decouples the control input. Third, by taking the optimization T–S fuzzy model as design model and by introducing the reconstruction of disturbance into controller, a feedback robust controller with disturbance compensation is designed to stabilize the affine nonlinear system. Finally, a simulation example of the crane model is given and some comparisons are provided to verify the effectiveness and show the advantages of the proposed method.