Spacecraft autonomous proximity rendezvous and docking using feedback motion planning

DOI编号  10.7641/CTA.2018.70834
2018,35(10):1494-1502

 作者 单位 E-mail 高登巍 西北工业大学 gaodengwei123@163.com 马卫华 西北工业大学 whma_npu@nwpu.edu.cn 袁建平 西北工业大学

航天器近距离交会对接过程中需要满足禁飞区, 对接走廊等约束, 否则会有航天器相碰或者损毁的风险. 本文 研究了一种基于线性二次型调节器树(linear quadratic regulator trees, LQR–Trees)反馈路径规划的安全交会对接的路径 规划与控制方法. 首先采用非线性规划算法(nonlinear programming, NLP)计算开环标称轨迹, 并应用局部线性反馈控 制算法生成闭环控制律使得系统状态保持在标称轨迹附近; 然后采用平方和(sums-of-squares, SOS)凸优化方法, 沿着标 称轨迹附近计算反向可达集; 最后采用相对稀疏的多个稳定域生成轨迹库覆盖大范围的状态空间, 扩展稳定区域. 本文 首次提出采用6维的LQR–Trees算法的安全对接轨迹规划与控制方法, 并重新设计了控制饱和约束. 仿真结果验证了该 算法在交会对接安全轨迹规划与控制中的有效性, 通过设计5个稳定域实现了满足对接走廊约束的安全交会对接任务.

The chase spacecraft is required to strictly comply with the constraints like keep-out zone and docking corridor during the rendezvous and docking (RVD) mission. A feedback motion planning algorithm based on linear quadratic regulator trees (LQR–Trees) is employed to design the control and trajectory. Firstly, a nonlinear programming (NLP) method is used to calculate an open-loop trajectory and control as the nominal trajectory. Local feedback control algorithm is used to design the control law to maintain the real trajectories along nominal trajectory. Secondly, Sums of squares convex optimization method is used to calculate the backward reachability set along the nominal trajectory. Finally, several sparse backward reachability sets are combined to cover a large state space and extend the region of stability. We firstly propose the six-dimensional LQR–Trees method in spacecraft safe RVD mission, redesign the control saturation and constraints. The simulation illustrates the effectiveness of safety control of spacecraft RVD mission via designing five stable regions to satisfy the docking corridor constraints.