Terminal adaptive output feedback variable structure control

Based on the Lyapunov stability theorem, an adaptive output feedback variable structure control (OFVSC) scheme is proposed in this study for a class of multi-input multi-output non-linear systems with matched and mismatched perturbations to solve regulation problems. First, a switching function is designed, and the system to be controlled is decomposed into two subsystems through a linear state transformation. Then the proposed OFVSC scheme is presented. A perturbation estimation algorithm is utilised in designing the proposed control scheme in order to overcome the problem of unmeasurable states. Adaptive mechanism is also employed so that the upper bounds of perturbations as well as perturbation estimation errors are not required to be known in advance. Furthermore, the resultant control system is capable of driving all the states into zero within a finite time and guaranteeing global stability. Finally, a numerical example is given for demonstrating the feasibility of the proposed control scheme.