Highly constrained entry trajectory generation
Highly constrained entry trajectory generation
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DOI：
10.1016/j.actaastro.2013.01.024
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发表时间：
2013-07
影响因子：
3.5
通讯作者：
Yu Xie;Luhua Liu;G. Tang;W. Zheng
中科院分区：
文献类型：
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作者：
Yu Xie;Luhua Liu;G. Tang;W. Zheng
提出了一种入口轨迹规划算法，可生成满足航路点、禁飞区以及其他路径和终端约束的可飞行轨迹。该算法策略性地将进入轨迹分为初始阶段和滑翔阶段。在初始阶段，使用标称攻角和恒定倾斜角来生成 3D 轨迹。在滑翔阶段，基于进化的进入加速引导逻辑（EAGLE）开发了规划器。规划器分为纵向子规划器和横向子规划器。对于纵向规划，阻力能量曲线表示为归一化非常规能量的五个分段线性函数，以使其与所需的轨迹长度和满足航路点和禁飞区约束所需的横向机动性一致。纵向子规划器确定倾斜角的大小，而横向子规划器确定用于通过航路点的倾斜角的适当符号，避开禁飞区，并最小化最终航向误差。迭代地使用纵向和横向子规划器，直到满足所有路径和终端约束。然后，采用跟踪器跟踪参考阻力加速度和航向角曲线，以生成可行的闭环进入轨迹。该方法使用通用航空飞行器模型进行了测试。模拟表明，生成的轨迹可以通过预定的航路点，避开禁飞区，并在允许的公差范围内达到所需的目标条件。
An entry trajectory planning algorithm that generates flyable trajectories satisfying waypoints, no-fly zones, and other path and terminal constraints is presented. The algorithm tactically divides the entry trajectory into the initial and glide phases. In the initial phase, a nominal angle of attack and a constant bank angle are used to generate the 3-D trajectory. In the glide phase, a planner is developed based on the evolved acceleration guidance logic for entry (EAGLE). The planner is divided into a longitudinal sub-planner and a lateral sub-planner. For longitudinal planning, the drag-energy profile is represented as five piecewise linear functions of the normalized non-conventional energy to make it consistent with both the desired trajectory length and the lateral maneuverability required to meet waypoint and no-fly zone constraints. The longitudinal sub-planner determines the magnitude of the bank angle, whereas the lateral sub-planner determines the appropriate sign of the bank angle for passing waypoints, avoiding no-fly zones, and minimizing the final heading error. The longitudinal and lateral sub-planners are iteratively employed until all path and terminal constraints are satisfied. Then, a tracker is employed to follow both the reference drag acceleration and the heading angle profiles to generate a feasible closed-loop entry trajectory. The approach is tested using the Common Aero Vehicle model. Simulations demonstrate that the generated trajectories can pass the predetermined waypoints, avoid no-fly zones, and achieve the desired target conditions within allowable tolerances.