基于线性引力场的运载火箭弹道设计研究  

Research on Trajectory Design of Launch Vehicle Based on Linear-gravity Field

作　　者：胡冬生[1] 童科伟[1] 张烽[1] 刘丙利[1] 李烁[1] HU Dongsheng;TONG Kewei;ZHANG Feng;LIU Bingli;LI Shuo(R&D Department,China Academy of Launch Vehicle Technology,Beijing 100076,China)

机构地区：[1]中国运载火箭技术研究院研究发展部,北京100076

出　　处：《弹道学报》2022年第1期9-16,共8页Journal of Ballistics

摘　　要：为了解决运载火箭末级小推重比情况下最优弹道设计的问题,达到火箭入轨速度损失更小、消耗推进剂更少的目的,采用更加准确的线性引力场模型,通过简化偏航程序角和协态变量,将真空飞行段最优推力方向转换为含有5个约束条件的两点边值问题进行求解,进而通过积分运动方程得出最优弹道。此外,结合运载火箭飞行的特点对迭代初值进行了研究,提出了协态变量和火箭飞行时间初值的设置方法,并归纳出基于线性引力场的运载火箭全程飞行弹道设计思路和设计流程。仿真结果表明:在正常推重比情况下该方法与传统方法的设计结果吻合,俯仰程序角基本呈线性变化;在给定的小推重比情况下,该方法速度损失更小,相比传统设计方法和迭代制导仿真可分别节省推进剂2.9%和2.1%,同时俯仰程序角已不能按线性化规律来设计。该设计方法具有较好的收敛性能和优化效果,对小推重比情况下的弹道设计具有良好的适应能力,可应用于运载火箭上升段全程弹道设计,也可为运载器在线轨迹规划等提供新思路。To solve the problem of optimal ascent trajectory design in case of small thrust-weight ratio of launch vehicle’s last stage,and send payloads into orbit with much less velocity loss and propellant consuming,a new trajectory design method based on more accurate line-gravity field was proposed by simplifying yaw program angle and co-states,which transfered the optimal thrust direction in vacuum flight into a two-point boundary value problem containing five constraints,and got the optimal trajectory by integrating motion equations.Furthermore,the initial values of iteration were analyzed according to launch vehicle’s flight features,and an estimation method of initial values of co-states and flight time was deduced,and a means and process of launch vehicle trajectory design in whole ascent flight based on linear-gravity field was put forward.The simulations show that this method generates the same results with the conventional method in situation of normal thrust-weight ratio,and pitch program angle varies nearly linearly.In situation of small thrust-weight ratio,this method generates much less velocity loss,saving 2.9%and 2.1%propellant compared with the conventional method and iterative guidance respectively,and pitch program angle varies non-linearly.This method is of good convergence and optimization effect,and can be well applied in trajectory design of small thrust-weight ratio and launch vehicle’s whole ascent flight.This method can also supply a new means of online trajectory planning,etc.

关 键 词：弹道设计 线性引力场 极小值原理 小推重比 

分 类 号：TJ303.4[兵器科学与技术—火炮、自动武器与弹药工程]