Improved fast global sliding mode control based on the exponential reaching law

In order to improve the control performance of the global sliding mode control method, a fast global sliding mode control method is proposed to accelerate the response of the system by changing the exponential decay function in the sliding surface as an exponential bilateral decay function which can make the dynamic sliding mode surface evolve into the linear sliding mode surface in the finite time. The exponential reaching law is used to design the control law, and Lyapunov stability theory is used to prove the stability of the system. The control method proposed in this article can be applied to control the uncertain nonlinear system. Simulation results show that the method has faster response rate than the conventional global sliding mode control method. The method can be used to control the quad-rotor unmanned helicopter, and its good practicability can be verified.