High-precision attitude controller design for deep space probe via adaptive fast terminal sliding mode control

In this paper, a high-precision attitude controller, based on the combination of fast terminal sliding mode control law and adaptive estimation theory, is designed for a class of deep space probes with unknown external disturbances, such as the gradient torque from universal gravitation, the solar radiation pressure because of solar shining. Besides, the variation of moment inertia matrix of the space probes during the whole flying course is also considered. The adaptive control theory and the fast terminal sliding control strategy are employed to estimate the lumped uncertainty and enhance the robustness of the attitude control system. Then, the Lyapunov stability theory is used to fulfill the stability analysis of this system. Finally, simulation results are obtained to validate the effectiveness of the proposed controller, which has a fast convergence rate and high control precision.