Quaternion-based fixed-time sliding mode attitude tracking control for rigid spacecraft without angular velocity measurement

Aiming at the spacecraft attitude tracking control with angular velocity sensor failure, a new fixed-time control method is proposed considering the disturbance and parameter uncertainty of the spacecraft. Based on the fixed-time adaptive state observer and the angular velocity estimation method, the attitude information and angular velocity of the spacecraft are estimated, respectively. Then a non-singular fixed-time sliding mode controller is designed according to the obtained angular velocity. The fixed-time stability of the system is proved by Lyapunov theory. Finally, the simulation can verify that the proposed scheme has faster convergence speed and better antiinterference ability.