The Application Of Sliding-Mode Variable Structure Control Theory In Nonlinear Systems

Sliding mode variable structure system has received wide attention because of it’srobustness to parameter perturbation and external interference. Because of the nonlinear systemhas many non-linear factors and interference, the sliding mode control system has been appliedwidely in it. In recent years, the sliding mode control system has been applied in many fields,such as robot systems, high-performance motor systems, power systems, etc. Sliding modevariable structure control process was made of approaching stage and sliding mode stage, thecontrol signals make the system slide from initial state to ultimate state steadily. For nonlinearsystems, my thesis has improved sliding controller from above two aspects，the purpose is toshorten control process time and improve movement quality. The main content as follows:Firstly, designing a new reaching law, it makes the system slide from the initial state tosliding mode fastly. Through MATLAB simulation, the simulation results show that thesuperiority of the reaching law.Secondly, adding the fuzzy control system in sliding mode control system, the new controlsystem has a better tracking effect and less human factors.The last, for robot system, a terminal sliding mode control method was designed. The mainfeature is it’s rapidity. Finaly, a global sliding mode was proposed. It can eliminate the frictioneffectively.