Hyperbolic function hybrid switching sliding surface design for discrete-time uncertainty systems

In this paper, a novel nonlinear sliding surface is designed for the discrete-time uncertain system. Two hyperbolic functions are introduced into the proposed novel sliding surface. With the appearance of these functions, the closed-loop system performance is improved. The sliding mode control law is derived based on the reaching-law approach and multirate output feedback technology. The reaching condition of the proposed sliding surface is proved, and the condition that ensures the stability of the closed-system is discussed. Finally, a simulation example is presented to illustrate the effectiveness of the proposed method.