Robust H_∞ sliding mode control for a class of uncertain switched delay systems

This article considers the robust H sliding mode control problem for a class of uncertain switched delay systems. A single sliding surface is constructed such that the reduced-order equivalent sliding motion restricted to the sliding surface is completely invariant to all admissible uncertainties. For cases of known delay and unknown delay, the existence conditions of the sliding surface are proposed, respectively. The corresponding hysteresis switching laws are designed such that the sliding motion is stabilisable with H disturbance attenuation level . Furthermore, variable structure controllers are developed to drive the state of the switched system to reach the single sliding surface in finite time and remain on it thereafter. Finally, two numerical examples are given to illustrate the effectiveness of the proposed design methods.