A novel approximate finite-time convergent guidance law with actuator fault

In this paper, a novel approximate finite-time convergent guidance law for missiles is presented to accurately intercept maneuvering targets when the actuators cannot perform as well as usual. First, the governing equations are proposed according to the relationship between missile and target at engagement phase, and a typical nonlinear mathematic model of actuator efficiency is built. Then, an adaptive multiple-input-multiple-output guidance law based on super-twisting algorithm is proposed to drive the line-of-sight angular rate to converge in a small region around zero in finite time. According to the proposed adaptive law, the information about maneuverability of target is not necessary, and the parameter drift problem is also addressed by dead-time control technique. Moreover, the proposed formulation is validated by means of the detailed stability analysis with strict Lyapunov function and simulation results.