可重复使用运载器的上升段轨迹线设计

Ascent trajectory design for reusable launch vehicles

可重复使用运载器的上升段飞行过程较为复杂,其轨迹线设计是一个多约束的非线性规划问题,优化求解较为困难。为形成较为实用的上升段轨迹线设计策略,将上升段分成投放分离段、拉起点火段、动力爬升段和无动力爬升段四段进行分析设计。通过各段运动特点的分析,各段采用不同的轨迹策略,确定所需要设计的参数及其范围,将各种物理约束及末端条件约束转换成适应度函数,最后将轨迹优化问题转化成设计参数的寻优问题,通过具有很强非线性搜索能力的粒子群优化算法对参数进行优化求解。结果表明,设计的轨迹线能很好地满足任务指标。

Ascent-trajectory optimization of reusable launch vehicles（RLV） is a difficult problem due to the complexity of many physical constraints and optimization cost surfaces.The ascent phase is divided into four segments for trajectory design,which are separation,lifting,power climb and un-power climb.The strategy for each segment trajectory is analyzed according to kinetic characters and the design parameters are studied.For trajectory optimization a heuristic technique based on a particle swarm optimization（PSO） algorithm is used.The highly constrained nonlinear trajectory planning problem is decomposed into design parameters search problems,the algorithm is able to generate a complete and feasible ascent trajectory,given the ascent conditions,values of constraint parameters and final conditions.Numerical simulation with a RLV model for ascent mission is presented to demonstrate the capability and effectiveness of the algorithm.