Abstract: To achieve the mission requirement of the state agreement within a small-satellite swarm composed of multiple CubeSats,an attitude synchronization control strategy of the CubeSat swarm based on adaptive control was proposed.Considering both undirected and directed swarm,an attitude dynamic model for the small-satellite swarm was constructed by introducing the synchronization signals,which reflected the interconnections of adjacent CubeSats.Based on the pairwise difference amongst the adjacent CubeSat,an adaptive controller was designed to improve the attitude synchronization of the swarm.Concerning the multi-unit CubeSat composed of standard modulars with a Micro-Pulse Plasma Thruster (μ-PPT) electric propulsion system,the three-axis attitude was adjusted based on discrete pulse control for CubeSat.Moreover,each CubeSat performed μ-PPT pulse adjustment by searching for the optimal pulse sequence combination,such that the attitude states eventually tended to be same and simultaneously the external disturbances were also continuously compensated.Through the simulation analysis of attitude synchronization for a networked CubeSat swarm,the results showed that the attitude synchronization of the CubeSat swarm could be effectively achieved under various information exchange modes based on the proposed adaptive control law and the μ-PPT propulsion system.

Key words: small satellite swarm, attitude synchronization, adaptive control, CubeSat, micro-pulse plasma thruster

摘要： 为实现由多个立方体卫星组成的微小卫星群落状态协同任务需求,提出一种基于自适应控制的立方体卫星群落姿态同步控制策略。考虑群落信息交互的无向性和有向性两种情况,通过引入反映邻接立方体卫星互联关系的同步信号,构建微小卫星群落姿态动力学模型。基于邻接状态差异对每个立方体卫星进行自适应控制设计,改善整体微小卫星群落的姿态同步性。考虑标准模块化多单元立方体卫星结构以及配置的微脉冲等离子推进器(μ-PPT)的特殊性,提出基于离散脉冲控制的立方体卫星三轴姿态调节。并且,群落中每个立方体卫星通过搜寻最优脉冲序列组合进行μ-PPT脉冲调节,能够使每个立方体卫星最终趋于姿态同步状态的同时,实现对外部干扰力矩的连续补偿。最后,通过对立方体卫星互联群落状态同步的任务需求进行具体案例的仿真分析,结果表明在多种信息交互模式下,提出的连续自适应控制律以及离散μ-PPT电推进系统,能有效实现立方体卫星整体群落的姿态同步任务需求。

关键词: 微小卫星群落, 姿态同步, 自适应控制, 立方体卫星, 微脉冲等离子推进器