Robust variable structure control algorithm based on T-S fuzzy model

In this parer, we propose a robust variable structure control algorithm based on Takagi-Sugeno (T-S) fuzzy model for a class of nonlinear systems. We use a T-S fuzzy model with mismatched uncertainty and time-varying delay to approximately represent the nonlinear systems. An asymptotically stable sliding surface is designed by means of linear matrix inequality (LMI). The sliding surface can compensate for the effect of the uncertainty. A robust variable structure controller is designed to ensure the existence of a sliding mode and to overcome the effect of the time-varying delay and the uncertainty. In addition, a novel reaching condition that can obviously reduce chattering around the sliding surface is also proposed. Matlab simulation results are offered to verify the effectiveness of the proposed algorithm.