Time-Varying Sliding Mode Based Fixed-Time Missile Guidance and Attitude Control With Impact Angle Constraints

Abstract

Considering an unpowered missile diving to intercept a maneuvering target, a novel fixed-time guidance and attitude control algorithm is proposed. First, the second-order derivatives of the aerodynamic angles are directly linked to the fin deflections, which can avoid the tracking of missile body angle rate instruction in the traditional methods. Second, a novel fixed-time time-varying parameter nonsingular terminal sliding mode guidance law is proposed, which can avoid control input singularity without switching to the polynomial form when the error approaches the origin. Third, a new global time-varying sliding mode with a predefined convergence time and analytical solution is developed to design the attitude controller. The system states are proved to be fixed-time convergence based on the Lyapunov stability theory. Six-degree-of-freedom simulations are conducted to validate the superiority of the proposed algorithm in terms of miss distance, impact angle error, interception time and control energy.