航天器编队飞行自适应协同避碰控制

Adaptive cooperative control of spacecraft formation flying with collision avoidance

摘要:

为解决航天器编队飞行系统中存在通信时延、参数不确定的跟踪问题,并实现避免碰撞的控制目标,基于编队航天器的相对运动非线性动力学模型和势函数方法,对航天器编队飞行系统的自适应协同避碰控制方法进行了研究. 首先,在全状态反馈控制的情况下,提出了一种对通信时延和参数不确定具有鲁棒性的自适应协同避碰控制律；其次,进一步考虑速度信息不可测量的情况,通过引入一种新型滤波器设计了无速度测量的自适应协同避碰控制律,使得编队航天器实现对期望轨迹的跟踪,同时能够保证航天器编队飞行系统中航天器在安全区域飞行,避免发生相互碰撞. 最后,针对全状态反馈和无速度测量反馈的情况分别分析了航天器编队飞行闭环系统的Lyapunov稳定性,显著增强了闭环系统对通信时延和参数不确定的鲁棒性.结果表明,所设计的两种自适应协同避碰控制律可以有效地保证编队飞行航天器对期望轨迹的跟踪,且系统可以实现避免碰撞的编队飞行任务.

Abstract:

To solve the tracking problems of communication delay and parameter uncertainty in spacecraft formation flying system and realize the control objective of collision avoidance, this study investigated the adaptive cooperative control of spacecraft formation flying system with collision avoidance based on the relative motion nonlinear dynamic model and the potential function method. First, an adaptive cooperative collision avoidance control law with full state feedback was proposed, which has the robustness to communication delays and parameter uncertainties. Then, considering the situation of unmeasurable velocity, a control law without velocity measurement was proposed by introducing a new type of filter, which can enable the formation spacecraft to track the desired trajectory and fly in the safe regions without collision. Finally, the Lyapunov stability of the spacecraft formation flying closed-loop system was analyzed for the cases of full state feedback and without velocity measurement feedback, and it was found that the robustness of the closed-loop system to communication delay and parameter uncertainty was significantly improved. Simulation results show that the proposed two adaptive cooperative control laws could guarantee that the formation spacecraft tracks the desired trajectory effectively and achieves the formation flying mission with collision avoidance.