Abstract: An improved flocking control strategy is proposed to solve the problem of collision free cooperative motion of satellite clusters. Firstly, combining the Prim algorithm and the breadth first algorithm, a topology optimization method is designed to calculate a degree and radius constrained minimum spanning tree, and the optimization results are used as the communication topology of the satellite cluster. This method can not only save the communication resources of each satellite, but also reduce the communication delay of the cluster network. Subsequently, in order to improve the rapidity of reference trajectory planning, a shape based approximation method based on Fourier series is adopted to calculate the reference trajectory of the leader satellite. On this basis, a flocking control strategy considering communication delay and collision avoidance is introduced, which can make the whole cluster move to the target point along the reference trajectory on the premise of ensuring communication connectivity, and there is no collision during the movement. After theoretical analysis, the asymptotic stability of the controller is proved by the Lyapunov Razumikhin theorem. Finally, the correctness and validity of the proposed control strategy are verified by numerical simulations.

Key words: Satellite cluster, Flocking control, Topology optimization, Communication delays, Collision avoidance