Adaptive Fuzzy Fixed‐Time Attitude Tracking Control for Rigid Spacecraft With Input Delay

ABSTRACT This paper investigates the fixed‐time adaptive fuzzy attitude tracking control problem for rigid spacecraft with input delay. Fuzzy logic systems (FLSs) are applied to perform online estimation of unknown nonlinear functions in a rigid spacecraft system. By introducing the hyperbolic tangent function, the potential singularity issue in the derivative of the virtual controller is solved. Specifically, a fixed‐time auxiliary system is designed to eliminate the effect of input delay. To this end, an adaptive fuzzy fixed‐time attitude tracking control scheme based on backstepping technology and fixed‐time theory is proposed. Under the proposed scheme, the boundedness of all signals in the closed‐loop system is ensured, and the tracking error converges to a small neighborhood of zero within a fixed time. Eventually, simulation results illustrate the validity of the scheme.