An Extended Multi-Surface Sliding Control for Matched/Mismatched Uncertain Nonlinear Systems Through a Lumped Disturbance Estimator

In this paper, we introduce a novel extended sliding mode control algorithm for a class of uncertain nonlinear system through a lumped disturbance estimator. The fundamental concept of this approach is to use multiple proportional-integral sliding surfaces to estimate the lumped disturbances generated by arbitrary matched/mismatched uncertainties. Following, an effectively extended sliding mode controller integrated with the estimated values is designed through the proposed series of sliding-surfaces to deal with the control problem of an uncertain nonlinear engineering model. The stability of both closed-loop control system and lumped disturbance estimator is achieved by Lyapunov theorem. The effectiveness of the proposed approach is demonstrated through simulation results of an illustrative example.