A Novel Integral Sliding Mode-Type Continuous Guidance Law With Autopilot Lag for Intercepting Non-Cooperative Maneuvering Targets

Abstract

This paper proposes an integral sliding mode guidance law with the constraints of the line-of-sight angle and its rate for the interception of a non-cooperative maneuvering target. The analytical guidance law is derived using an integral sliding mode control and an inertial delay control allowing for unknown uncertainties. The guidance law is further advanced to achieve exponential convergence and high terminal guidance accuracy with autopilot lag. This is accomplished by applying dynamic surface control and fractional order filters. Finally, the finite-time stability of the guidance law with and without missile autopilot lag is demonstrated. In addition to its robustness and precision, there are other benefits of this proposed guidance law. First, the proposed guidance law can effectively attenuate an abrupt change in guidance commands during the terminal homing phase in the presence of uncertainties without prior information. Second, the design parameters in the inertial delay control are decoupled with the integral sliding mode control. This decoupling supplies more degrees of freedom to regulate the performance of guidance commands. Third, the finite-time convergence of the proposed guidance law is guaranteed while accounting for the approximated second-order dynamics and uncertainties of the missile autopilot. Theoretical analysis and numerical simulations were conducted to demonstrate the efficiency of the proposed guidance law.