Achieving a desired terminal approach angle is required by an advanced entry vehicle in missions of landing or defense penetration. An entry guidance method is developed to satisfy the terminal approach angle constraint as well as the conventional constraints. The guidance method consists of a lateral guidance logic based on multiple aiming points and a two-phase trajectory tracking law. The aiming points are selected from a reference ground track and used to determine bank reversals for the lateral guidance logic. With the aid of aiming points, the vehicle can reach the entry terminal in a desired direction. The two-phase trajectory tracking law, corresponding to a two-dimensional and a three-dimensional trajectory, are designed to cooperate with the lateral guidance logic. Numerical results show that the guidance method is capable of flying the vehicle to the terminal zone with various desired approach angles, and meanwhile, robust to typical entry dispersions. The advantage of the guidance strategy is also verified by comparisons.

在登陆或防御穿透的任务中，高级进入车辆需要获得期望的终端接近角。开发了一种进入引导方法来满足终端接近角约束以及常规约束。制导方法由基于多个瞄准点的横向制导逻辑和两相轨迹跟踪定律组成。瞄准点是从参考地面轨迹中选择的，用于确定侧向引导逻辑的坡度反转。借助瞄准点，车辆可以沿所需方向到达入口终端。设计了与二维和三维轨迹相对应的两相轨迹跟踪定律，以与横向引导逻辑配合。数值结果表明，该制导方法能够以各种期望的进近角将飞行器飞行到终点区域，同时对典型的进入色散具有鲁棒性。通过比较也验证了指导策略的优势。