Robust static output feedback variable structure control for nonlinear systems

In this paper, a robust stabilization problem for nonlinear systems is investigated using static output feedback. Matched and mismatched uncertainties are considered and their bounding functions take general forms. Based on a Lyapunov analysis approach and sliding mode techniques, some conclusions are presented. Then, a robust nonlinear variable structure control scheme is synthesized to stabilize the system globally, and it is not necessary for the nominal system to be linearizable globally. The conservatism is reduced by using uncertainty bounds in the control design. Finally, a mass-spring system is employed to illustrate the effectiveness of the results.