针对无角速度量测及饱和输入条件下的编队姿态协同控制问题，将未知饱和控制影响与外部扰动合并为复合外部扰动，设计了一种外部状态观测器准确估计系统角速度和复合外部扰动；在此基础上，提出了一种有限时间滑模协同控制律，通过构造合适的Lyapunov函数从理论上证明了系统的稳定性；仿真结果表明，该方法能够在有限时间内实现对姿态的准确估计和协同控制。

This paper focuses on the attitude tracking control problem of spacecraft formation flying under unmeasured angular velocity and saturation input.By combining the unknown saturation effect with the external disturbance into a compounded disturbance,a novel finite-time observer was designed to estimate the angular velocity and compounded disturbance.Based on which,a finite-time sliding-mode cooperative control protocol was proposed.The stability of the system was verified theoretically by constructing an appropriate Lyapunov function.Simulation result shows that the method can implement accurate estimation and cooperative control to the attitude in limited time.