摘要
针对月面高精度下降着陆问题,提出了一种基于最优观测器的参数自适应凸优化月面着轨迹规划算法。首先,针对下降着陆主减速段需要尽可能减少燃料消耗的问题,考虑约束及动力学模型的非凸性,采用无损凸化技术将月面下降着陆问题转化为二阶锥规划问题;其次,为减少下降着陆过程中质量、比冲等参数不确定性影响,设计了基于Riccati方程的最优观测器;再根据标称参数凸优化所产生的最优轨迹进行飞行,利用该过程中加速度计实时测量信息,结合推力器输出信息,实现对着陆器参数的在线实时估计;在参数估计实现收敛后,通过在线求解二阶锥规划问题实现最优轨迹的在线规划。仿真结果表明,该观测器能够实现在线参数实时估计;该算法相较其他定点着陆算法,仅需要发动机具有离散的推力域,且具有精度更高的优势。
A parametric adaptive convex optimization lunar landing trajectory planning algorithm based on the optimal observer is proposed for the lunar surface descent landing problem with high accuracy.Firstly,to address the need of minimizing fuel consumption in the main deceleration section of the descent landing,the lunar surface descent landing problem is transformed into a second-order cone planning problem by considering the constraints and the nonconvexity of the dynamical model using a lossless convexification technique;secondly,an optimal observer based on the Riccati equation is designed to reduce the influence of the uncertainty of parameters such as mass and specific impulse during the descent landing process;then the optimal trajectory generated according to the nominal parametric convex The optimal trajectory generated by the optimization is then flown,and the online real-time estimation of the lander parameters is achieved by using the real-time accelerometer measurement information in the process,combined with the thruster output information;after the convergence of the parameter estimation is achieved,the online planning of the optimal trajectory is realized by solving the second-order cone planning problem online.The simulation results show that the observer can achieve online parameter estimation in real time;the algorithm only needs the engine to have a discrete thrust domain compared with other fixed-point landing algorithms,and has the advantage of higher accuracy.
作者
穆荣军
邓雁鹏
吴鹏
MU Rongjun;DENG Yanpeng;WU Peng(School of Astronautics,Harbin Institute of Technology,Harbin 150001,China)
出处
《宇航学报》
EI
CAS
CSCD
北大核心
2023年第11期1659-1669,共11页
Journal of Astronautics
基金
国家载人航天专项第四批预研项目(18123060201)
上海航天科技创新基金(SAST2021-024)。
关键词
月面着陆
参数不确定性
参数自适应
凸优化
二阶锥规划
Lunar landing
Parameter uncertainty
Parameter adaptive
Convex optimization
Second order cone programming(SOCP)
