A novel hybrid scheme for fixed-time SOSM control of nonlinear uncertain systems subject to mismatched terms

Abstract

In this paper, a novel second-order sliding mode (SOSM) controller is proposed for a general class of uncertain nonlinear systems in the presence of mismatched terms. The proposed SOSM controller is based on a hybrid scheme which switches between two different controllers. The former fixed-time attractive controller can drive the sliding variables into a closed compact set of the origin in a time that do not depend on system initial values. The latter finite-time controller can drive the sliding variables to zero. Strict Lyapunov analysis show that the controlled system under the proposed hybrid controller can guarantee the globally fixed-time stability of the closed-loop system. A simulation example under different initial values is given to show the effectiveness of the theoretical results.