主从式编队航天器连通性保持与碰撞规避

针对主从式航天器编队过程中存在的通信距离约束、航天器之间的碰撞以及空间干扰等问题，提出一种基于非线性干扰观测器和人工势函数的分布性协同控制方法。当初始通信网络连通时，通过在分布式协同控制器中引入吸引势函数，保证整个编队过程中通信网络始终是连通的。针对主航天器速度仅有部分从航天器直接可知的情况，为每一个从航天器设计分布式的速度观测器估计主航天器的速度，从而实现航天器之间的速度协同。此外，通过在控制器中引入非线性干扰观测器对外界干扰进行观测，显著增强了航天器编队的精度。仿真结果表明，本文提出的分布式协同控制方法不但能够实现对主航天器的速度跟踪以及航天器之间的队形保持，而且能够在编队过程中实现通信网络的连通性保持和航天器之间的碰撞规避。

Connectivity Preservation and Collision Avoidance for Leader Follower Spacecraft Formation Flying

A distributed coordination control method based on artificial potential function and nonlinear disturbance observer is proposed to avoid collisions and preserve network connectivity for leader-follower spacecraft formation flying. By adding an attractive potential function to the distributed controller, the communications network can be connected at all time if the initial network is connected. Since the leader’s state is only known by its neighbors, a distributed velocity observer is designed to estimate the leader’s state for all followers. Finally, a nonlinear disturbance observer is integrated with the distributed controller to improve the accuracy of formation. The simulation results show that the proposed method can not only realize the collision avoidance between spacecraft under the premise of tracking the velocity of the leader, but also ensure the connectivity of the communications network during formation flying.