A Novel Global Fast Terminal Sliding Mode Control Scheme for Second-Order Systems

To speed up the response and reduce the chattering of a sliding mode control system, a novel reaching law with two variable power terms is proposed, which makes the system have a fast approaching rate either far away from or close to the sliding surface. Moreover, an improved global fast terminal sliding surface with the dynamic coefficients is proposed, which can make the system states arrive at the equilibrium point along the sliding surface with a fast convergence rate. Furthermore, a novel global fast terminal sliding mode controller is designed by employing the proposed reaching law and sliding surface, which can quicken the convergence rate of the system states in both the reaching phase and the sliding phase. Theoretical analysis shows that the proposed controller can ensure finite-time convergence. Experiment results are presented to verify the effectiveness and superiority of the proposed global fast terminal sliding mode control scheme.