基于NTSM的航天器特征点凝视跟踪控制  

NTSM-based kinematically-coupled motion control for spacecraft’s feature points staring and tracking

作　　者：傅江良 甘庆波 张扬[1] 赵柯昕 袁洪[1] FU Jiangliang;GAN Qingbo;ZHANG Yang;ZHAO Kexin;YUAN Hong(Academy of Opto-Electronics, Chinese Academy of Sciences, Beijing 100094, China;National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100101, China;University of Chinese Academy of Sciences, Beijing 100049, China)

机构地区：[1]中国科学院光电研究院,北京100094 [2]中国科学院国家天文台,北京100101 [3]中国科学院大学,北京100049

出　　处：《系统工程与电子技术》2019年第7期1623-1632,共10页Systems Engineering and Electronics

基　　金：国家自然科学基金(91638301,U1731131);中国科学院青年创新促进会(2018183);中国科学院光电研究院创新项目(Y70B14A18Y)资助课题

摘　　要：针对航天器特征点凝视以及随动跟飞问题,提出了一种建立在目标特征点指向(feature point directing , FPD)坐标系下的相对运动动力学模型,并基于非奇异终端滑模方法(nonsingular terminal sliding mode, NTSM)实现了航天器的相对姿轨耦合控制。首先,以凝视跟踪的目标特征点为原点,跟踪指向轴为主轴,建立了FPD 坐标系下的特征点相对运动模型,该模型在控制过程中可以保持特征点相对运动期望状态稳定不变,从而降低了末端约束的处理难度。其次,基于NTSM方法设计了一种有限时间控制律,并对其稳定性和滑模到达时间进行了分析,理论证明了该控制律满足Lyapunov稳定性条件,且系统能在有限时间内迅速收敛到平衡状态。最后,仿真结果表明FPD坐标系下的特征点相对运动模型以及NTSM控制律在求解特征点凝视跟踪问题上具有良好的性能和普适性,研究成果对空间在轨维护、空间操控以及深空小天体悬停着陆等具有一定的理论参考价值。Considering the issue of rapidly tracking and long-term staring between two feature points attached to a chaser spacecraft and a tumbling target respectively, a new model for relative kinematically-coupled motion of two feature points is derived in feature point directing (FPD) frame originated in the target’s feature point, and the nonsingular terminal sliding mode (NTSM) technique is applied both for the relative orbit and the attitude control . Firstly, compared with the traditional point-mass models derived in target’s LVLH frame, the new proposed model not only reduces the computational complexity when determining the relative reference trajectories, but also simplifies the conditions of the terminal constraint. Next, based on the NTSM method, a finite-time controller for coupled translational-rotational dynamics is established. Through theoretical analysis, results show that the proposed controller could satisfy the Lyapunov stability condition and guarantee the tracking errors to reach zero in finite time. Finally, numerical simulations are given to demonstrate that both orbital and attitude relative motion track the reference trajectories well under the proposed control law. The article also provides a certain reference for future space on-orbit maintenance, manipulation and asteroid hovering and landing in deep space.

关 键 词：航天器特征点 特征点指向坐标系 姿轨耦合动力学 有限时间控制 非奇异终端滑模 凝视跟踪 

分 类 号：V448.2[航空宇航科学与技术—飞行器设计]