To solve the problem of attitude synchronization control for spacecraft formation flying (SFF) suffering from external disturbances under a directed communication topology, a sliding mode disturbance observer (SMDO) based on the finite-time control strategy is developed to observe the time-varying external disturbance via estimating the upper bound of its first derivative. Meanwhile, the rotation matrix is employed to describe the attitude of SFF for the purpose of the avoidance of singularity and unwinding phenomenon. As for the attitude synchronization and the tracking control architecture, a sliding mode surface (SMS) is given such that the control objective can be achieved. The effectiveness and the validity of the proposed method are elaborated via theoretical analysis and numerical simulations.

中文翻译：

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基于扰动观测器的航天器有限时间协调姿态跟踪控制（3）

为解决定向通信拓扑下航天器编队飞行（SFF）受到外界干扰的姿态同步控制问题，开发了基于有限时间控制策略的滑模干扰观测器（SMDO）来观测时变外部通过估计其一阶导数的上限来确定扰动。同时，采用旋转矩阵来描述SFF的姿态，以避免奇异和退绕现象。至于姿态同步和跟踪控制体系结构，给出了滑动模式表面（SMS），从而可以实现控制目的。通过理论分析和数值模拟，阐述了该方法的有效性和有效性。