基于一致性理论,研究了多航天器系统相对轨道及姿态耦合的分布式协同控制问题。在仅有部分跟随航天器可获取领航航天器信息的情形下,针对各跟随航天器存在未建模动态以及外部环境干扰等问题,利用双曲正切函数的性质,提出了考虑输入饱和的分布式自适应协同控制律。首先,对于领航航天器具有时变状态的情形,为每个跟随航天器设计了3个滑模估计器,对领航航天器的状态进行估计。其次,针对跟随航天器间相对速度和角速度难以测量的问题,设计仅需领航航天器状态的切比雪夫神经网络自适应更新律。最后,设计考虑输入饱和的分布式自适应协同控制律保证各跟随航天器跟踪动态领航航天器。仿真结果表明了该算法的有效性、可行眭。
Based on the consensus theory, distributed coordinated control for coupled relative orbits and attitudes of a multiple spacecraft system is investigated. With adoption of hyperbolic tangent function, more specifically, a distributed adaptive coordinated control algorithm is proposed for the case that the leader spacecraft state may only be available to only a subset of follower spacecrafls in the presence of input saturation constraints and external disturbances. Firstly, for the case that the leader spacecraft has the time-varying trajectory, three sliding-mode estimators are presented for each follower to obtain the estimates of the leader spacecraft' s information. Then, for the case that the relative velocities and relative angular velocities among the follower spacecrafts are not measured, an adaptive law based on Chebyshev neural networks is proposed only using the leader' s information. Furthermore, the distributed adaptive coordinated control algorithm with input saturation enables a fleet of followers to track the dynamic leader spacecraft. Simulation results illustrate effectiveness and feasibility of the proposed algorithm.