经济型月球探测器精确定点软着陆制导算法  

A Guidance Algorithm for Pinpoint Soft Landing of Economical Lunar Lander

作　　者：高峰 荆武兴[1] 高长生[1] 李志刚 钟伟 GAO Feng;JING Wu-xing;GAO Chang-sheng;LI Zhi-gang;ZHONG Wei(Department of Aerospace Engineering,Harbin Institute of Technology,Harbin 150001,China;Aerospace System Engineering Shanghai,Shanghai 201109,China)

机构地区：[1]哈尔滨工业大学航天工程系,哈尔滨150001 [2]上海宇航系统工程研究所,上海201109

出　　处：《宇航学报》2021年第10期1246-1256,共11页Journal of Astronautics

基　　金：国家自然科学基金(11172077);载人航天预研项目(060101,0109)。

摘　　要：针对未来经济型月球探测器精确定点软着陆问题,考虑发动机特性及终端状态约束,对主减速段制导算法进行了研究。首先考虑到未来月球通信网络的建立和资源的利用,提出了一种探测器在环月极轨道运行时的月面着陆点全覆盖环月调相策略。然后在北东地坐标系下建立软着陆主减速段的质心动力学模型,依据动力学模型将探测器的运动分为纵向平面运动和横向运动并分别设计在线闭环制导律。纵向平面运动采用改进显式制导算法,并基于有限推力思想和主减速段误差传播特性设计了满足终端航向位置约束的点火角修正策略;对于横向运动控制,首先基于ZEM/ZEV最优反馈制导律给出横向制导指令,然后采用PWPF将连续形式的制导指令调制为脉冲形式。仿真结果表明了该制导律能够满足所有终端状态约束,具有燃耗次优性、自主性、实时性和一定的鲁棒性,同时易于工程实现。Considering the characteristics of the motors and terminal state constraints,the guidance algorithm for pinpoint soft landing of an economical lunar lander is studied in this paper.Firstly,considering the establishment of future lunar communications network and the utilization of resources,a strategy of phasing is studied when the lander travels in the lunar polar orbits,which can cover all lunar landing sites.Then the dynamics model of the main descent phase is established in the NED frame.The motion of the lander is divided into the longitudinal plane motion and lateral motion,and their online closed-loop guidance algorithms are designed respectively.The longitudinal plane motion adopts an improved explicit guidance,and a fire angle correction strategy which satisfies the terminal course position constraint is designed based on the finite thrust theory and the error propagation characteristics of the main descent phase.For the lateral motion control,the guidance instructions are given based on the ZEM/ZEV optimal feedback guidance law,then the pulse control laws are calculated from the continuous laws with PWPF modulation.The simulation results show that the guidance algorithm is able to satisfy all terminal state constraints with good performance,and is easily implemented in engineering.

关 键 词：经济型月球探测器 改进显式制导 点火角修正 ZEM/ZEV PWPF 

分 类 号：V448.2[航空宇航科学与技术—飞行器设计]