| 摘要: |
| 由于动力系统及测控资源的约束，工程中存在着末级两次点火但滑行时间受限的运载火箭真空段弹道设计问题。基于线性引力场的假设，引入含滑行时间约束的切换条件，从而将含固定滑行时长的弹道优化问题转换成对两点边值问题的迭代求解和对运动方程的积分，并通过多个算例仿真验证了该方法的正确性和有效性。同时，研究了迭代过程中滑行段不同弹道预报方法对弹道设计的影响，结果显示较高的预报精度可以获得更优的弹道设计结果。该方法提供了一种新的弹道设计思路，在总体方案论证或初步设计阶段可以替代传统设计方法，以有效提升弹道设计效率，优化火箭方案。 |
| 关键词: 滑行时间约束 切换条件 两点边值问题 弹道设计 |
| DOI： |
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| 基金项目:国家自然科学基金（61703437）；国防科技基础加强计划技术领域基金（2022-JCJQ-JJ-0641） |
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| Research on Vacuum Trajectory Design with Coasting Time Constraint |
| HU Dongsheng,LIU Nan,TONG Kewei,LI Shuo,ZHANG Hao |
| (Research and Development Center, Department, China Academy of Launch Vehicle Technology, Beijing 100076, China;Technology and Engineering Center for Space Utilization, Chinese Academy of Sciences, Beijing 100094, China) |
| Abstract: |
| Considering constraints of propulsion system and tracking＆telecommunication, trajectory design problem of launch vehicle with twice-burn last stage and constrained coasting time is put forward. Based on line-gravity field, by introducing switching condition with coasting time constraint, the trajectory optimization is transferred into iterative solving of two-point boundary value problems and integration of motion equations. Two design examples are simulated, which verifies the validity and veracity of this method. Meanwhile, the influence of different coast arc prediction methods during iterative solving on trajectory design is studied, which shows that higher prediction accuracy can lead to better design results. The method provides a new idea for trajectory design, and can substitute the current design method during phase of general scheme reasoning or preliminary design, in order to greatly promote the efficiency of trajectory design and optimize launch vehicle scheme. |
| Key words: Coasting time constraint Switching condition Two-point boundary value problem Trajectory design |