A comparative study on switching surface design for sliding mode control

One of the important steps to build the sliding mode control system is to design the switching surface. There are many methods that have been developed in order to obtain the switching surface. The aim of this thesis is to study and analyze different switching surface design methods for sliding mode control of the uncertain systems. The main problem to be solved is how to design the switching surface with different methods. The design methods are applied to the same systems which are operating under the uncertainty conditions. The required objective is to attract all the state vectors to the switching surface so as to obtain the desired performance. The final step will be designing the sliding mode controller to enforce the state vectors towards the designed switching surface and to remain on the manifold until reaching the equilibrium point. Three different approaches of designing switching surface are studied here, the variable structure controllers are presented according to each method through the reaching condition of sliding mode. Key Words: Variable structure systems, sliding mode control, switching surface.