MMU月面起飞燃耗最省轨迹和推力设计研究  

STUDY ON TRAJECTORY AND THRUST DESIGN WITH LOWEST FUEL CONSUMPTION OF MMU TAKING OFF FROM LUNAR SURFACE

作　　者：韩艳铧 洪军停 张勇 Han Yanhua;Hong Junting;Zhang Yong(College of Astronautics,Nanjing University of Aeronautics and Astronautics,Nanjing 211106,China;UAV Research Institute,Nanjing University of Aeronautics and Astronautics,Nanjing 211106,China;Key Laboratory of UAV Technology,Nanjing University of Aeronautics and Astronautics,Ministry of Industry and Information Technology,Nanjing 210016,China)

机构地区：[1]南京航空航天大学航天学院,南京211106 [2]南京航空航天大学无人机研究院,南京211106 [3]南京航空航天大学无人机先进技术工业和信息化部重点实验室,南京210016

出　　处：《动力学与控制学报》2021年第6期8-15,共8页Journal of Dynamics and Control

基　　金：中央高校基本科研业务费青年科技创新基金(NT2020025)。

摘　　要：载人机动装置(MMU)携载航天员在月面机动飞行包括上升转弯段、巡飞段、转弯下降段,本文研究上升转弯段燃耗最省轨迹和主发动机推力优化问题.首先采用Pontryagin极小值原理,推导出MMU发动机推力大小和方向的最优函数形式.结果表明,推力大小是开关形式,且最多切换一次,故只需用"开"和"关"持续时间两个参数描述;推力方向角的余切是时间的仿射函数,只需用该函数的斜率和截距两个参数描述.上升转弯段和巡飞段交接,故上升转弯段的末状态受飞行高度、速度大小和方向三个条件约束,这样就将燃耗最省最优控制问题转化为三等式约束下的四参数非线性规划问题,设计自由度仅为一,只需用单自由度搜索即可快速求解.数值仿真验证了本文所提方法的有效性.The flight of Manned Maneuvering Unit(MMU)carrying an astronaut above lunar surface contains climbing turn segment,cruise flight segment,and turning down segment. The paper studied the trajectory and main engine’s thrust optimization problem aiming at the lowest fuel consumption for the climbing turn segment. Firstly,Pontryagin Minimum Principle was used to derive the optimal function forms of magnitude and direction angle of main engine’s thrust.Theoretical analysis demonstrated that the engine should work in switch mode with at most one switching,meanwhile the cotangent function of direction angle was an affine function of time. Therefore the engine’s optimal thrust function can be determined by four parameters,which are duration times of “on” and “off”,slope and intercept parameters of the affine function mentioned above. The climbing turn segment was needed to transition smoothly to the cruise flight segment,thus the terminal flight states of MMU in climbing turn segment are required to meet three pre-assigned parameter values,i.e.,flight height,flight velocities magnitude and direction. Then the optimal control problem with the lowest fuel consumption was transformed to a nonlinear programming problem involving four variables and three equality constraints.One design freedom was left,meaning that solution can be obtained easily by one-dimensional search. The effectiveness of the proposed method is verified by numerical simulations.

关 键 词：月面低空机动飞行 载人机动装置(MMU) 燃耗最省 最优控制 最优轨迹 

分 类 号：V476.3[航空宇航科学与技术—飞行器设计]