Adaptive Variable Structure Control for Set-Point Regulation of a Class of Nonlinear Systems

This paper presents an adaptive variable structure con-troller(VSC) for set-point regulation of a class of non-linear systems. Due to the existence of the sign function , the conventional VSC has the input chattering phenomenon even in the steady state. The method used in this paper essentially solves the problem by using a decreasing switching control input whose size is proportional to the tracking error. The chattering phenomenon due to the switching controller will diminish as the tracking error decreases in the steady state. In contrast with other methods, it does not involve any function approximation or state augmentation.