捕获非合作目标后航天器的自主稳定技术研究

捕获非合作目标后航天器质量特性发生突变,这大大地增加了系统的不确定性,控制不当容易导致失稳.为避免控制过程中航天器出现较大系统干扰问题,提出了先识别捕获后的系统质量特性,而后合理摆放非合作目标的自主稳定策略.首先,对航天器捕获过程和自主稳定策略进行了描述;其次,依据动量矩定理建立了非合作目标与航天器组合系统的数学模型,推导了非合作目标位置与质量特性之间的关系;然后,基于航天器数学模型和姿态测量信息,采用非线性规划方法对质量特性进行了辨识;最后,利用滑模变结构理论设计了非合作目标的控制回路,采用Lyapunov理论对系统的稳定性进行了分析.仿真结果表明:本文提出的自主配平策略响应快、精度高,适合在轨服务.

Research Automatic Stability Technology of Spacecraft Assembly with Captured Non-cooperative Targets on Orbit

After capturing non-cooperative targets, the mass properties of the spacecraft change abruptly, which makes the system uncertain and unstable. To avoid excessive interference during the control process, an automatic balancing strategy is proposed which identifies the mass properties of the assembly and then moves the non-cooperative targets. First, the capturing process of non-cooperative targets and the automatic balancing strategy are described. Secondly, based on the theorem of the moment of momentum, the dynamic models of the assembly are generated, and the analytical relationship between the location of the non-cooperative target and the offset of the centroid is derived. Thirdly, based on the information measured by the optical gyros, a nonlinear programming method is used to get the mass properties. Finally, the sliding mode variable structure control theory is used to design the control loop of the non-cooperative targets, while the stability of the system is analyzed by Lyapunov theory. It is demonstrated that the strategy proposed in this paper is effective and suitable for services on-orbit.