Smooth sliding mode control for missile interception with finite-time convergence

A novel smooth nonsingular terminal sliding mode control (SNTSMC) method is proposed for a class of second-order nonlinear systems which is then applied to the partial integrated guidance and control design of the hit-to-kill interception problem. First, two novel smooth sliding mode control methods were proposed, both of which can achieve fast finite-time convergence for uncertain systems and bring better performance of control inputs. Different from the existing sliding mode control laws, the proposed control laws were inherently continuous without using the saturation function to substitute the sign function, and the chattering problem was well solved. Finite-time stability was strictly proved via Lyapunov stability theory, and the accurate expressions of the convergent regions were given. Second, the proposed control methods were applied to the partial integrated guidance and control design. Finally, simulations were conducted to verify the effectiveness of the proposed methods. A comparison study with the conventional nonsingular terminal sliding mode control method in revealed that the proposed smooth control laws have better performance.