Observer-based sliding mode control for Ito stochastic time-delay systems with limited capacity channel

This paper investigates the problem of sliding mode control for a class of Ito stochastic time-delay systems over network communication links. The signals between plant and controller are exchanged over limited capacity channel, and are subject to logarithmic quantization before being transmitted. The main difficulty in this networked control problem is that, a sliding mode surface cannot be designed based on quantized outputs q(y(t)) directly since q(y(t)) is a piecewise constant and is not continuous in the quantizer switching times. To overcome this obstacle, in this paper, a state observer is designed to generate the estimation of system states, based on which a sliding mode controller is designed to stabilize the resulting closed-loop system. It is furthermore illustrated that the designing sliding mode controller can guarantee the reachability of the addressed sliding surface. A numerical simulation is performed to illustrate the effectiveness of the design control technique. (C) 2011 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.