Contents I. Introduction
Sliding mode control (SMC) systems have been extensively studied and successfully applied to solving many industrial problems [1]. The essence of SMC lies in the effort that in a vicinity of a prescribed switching manifold, the velocity vectors of the controlled state trajectories always point toward the switching manifold. An ideal sliding mode exists only when the system state satisfies the dynamic equation that governs the sliding mode for all time. This requires an infinite switching in general. It is known that, if the SMC is implemented in networked control environment, it is inevitable that there will be communication delay in control signals, which may deteriorate significantly the elegant invariance property enjoyed by the continuous-time SMC. The question is to what extent such influence is detrimental? Little research has been done except for some related results in discretization of SMC systems ([2], [3]).
