可重复使用运载器滑翔段轨迹快速优化方法

针对滑翔段轨迹多约束、强耦合、高非线性等特点,设计了一种全新的纵向飞行剖面,实现了终端约束和拟平衡滑翔条件的自动满足,并将滑翔段轨迹优化问题转化为一个双参数寻优问题。同时考虑倾侧角大小及其变化率约束,对侧向轨迹进行了设计。最后,设计了一种改进粒子群优化算法,通过外点法对约束条件进行处理,并提出一种变异策略对种群多样性进行准确控制,避免粒子陷入局部最优。仿真结果表明,该优化方法能够快速生成满足所有约束条件的最优滑翔轨迹;对于航程超过3000 km的场景,轨迹优化平均时间仅为5.94 s,最大终端相对误差不超过1%。

Fast Gliding Trajectory Optimization for Reusable Launch Vehicle

In view of the fact that the glide trajectory is multi-constrained,strong coupled,and highly nonlinear,a novel longitudinal flight profile is proposed. Based on this profile,terminal constraints and the qusi-equilibrium glide condition can be easily satisfied. Then the original trajectory optimization problem is converted into a parameter optimization problem with only two unknown variables. At the same time,the lateral motion is designed in view of the constraints on the bank angle and its angular rate. In addition,an improved particle swarm optimization( PSO) method is proposed. In PSO,the externalpoint method is used to take use of infeasible particles and a turbulence operator is proposed to control the diversity of the swarm,so less computational cost is required to get the optimal trajectory that meets all the flight constraints. Results of numerical simulation demonstrate the effectiveness of the proposed method. For the scenario in which the range is over 3000 km,the average CPU runtime is only 5. 94 s and the maximum terminal relative error is less than 1%.