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.