Discrete output feedback sliding-mode control with integral action

This paper presents a novel approach to the problem of discrete time output feedback sliding-mode control design. The method described applies to uncertain systems (with matched uncertainties) which are not necessarily minimum phase or relative degree one. A new sliding surface is proposed, which is associated with the equivalent control of the output feedback sliding-mode controller. Design freedom is available to select the sliding surface parameters to produce an appropriate reduced-order sliding motion. In order for this to be achieved, a static output feedback condition associated with a certain reduced order system obtained from the original plant must be solvable. The practicality of the results are demonstrated through the implementation of the controller on a small DC motor test rig. Copyright (c) 2005 John Wiley & Sons, Ltd.