Controller Design of Multivariable Variable Structure Systems with Nonlinear Switching Surfaces

A sliding mode control for linear multivariable systems in the presence of disturbances and parameter variations is considered. In the previous sliding mode control, the switching surfaces are linear functions and therefore the speed of response is relatively slow. To solve this problem, a new method, using nonlinear switching surfaces, is introduced so that the speed of response is improved, and the good transient response can be obtained. Simulation results are presented and they show the advantage of the proposed nonlinear switching surfaces.