Global Finite-Time Adaptive Attitude Control for Coupled Spacecraft With Model Uncertainty and Actuator Faults

Abstract

In this brief, a global finite-time adaptive attitude control algorithm is investigated for flexible spacecraft with slosh structure under model uncertainty, external disturbance, and actuator fault. First, the arctangent function (AF) surface is designed to realize the faster convergence time of quaternion-descripted attitude control system. Then, based on AF, an adaptive fault-tolerant control (FTC) algorithm is proposed to realize global finite-time attitude control of coupled spacecraft. The merit of the designed control algorithm is that it assumes that the upper bound of the lumped uncertainty (including model uncertainty related to angular velocity) is less than the combination of a positive constant, angular velocity, and control torque, rather than just less than a positive constant. The Lyapunov technique is used to prove the stability of whole closed-loop system. Numerical examples are performed to prove the efficiency of the designed control algorithm.