A look angle shaping guidance law with impact angle and seeker's field-of-view (FOV) constraints considering the time-varying speed is proposed. A look angle profile with respect to the relative range is first constructed as a cubic polynomial. The desired impact angle and the maximum look angle are expressed as functions of a parameter in the look angle profile. The impact angle constraint under limited FOV is achieved by solving this parameter with boundary conditions. Moreover, the feasible region of the desired impact angle is derived to ensure seeker's lock-on condition. By combining the first order look angle dynamics and the reference look angle profile, the impact angle control guidance (IACG) law with FOV constraint is obtained. The proposed guidance law is derived without relying on the linearized engagement kinematics, switching logic, constant speed assumption, and the LOS rate information during the guidance process. Moreover, the proposed guidance technique is helpful for user/designers to select feasible impact angle constraints in advance without tuning parameters. Finally, numerical simulations under a realistic model are performed to validate the effectiveness of the proposed guidance law.

提出了一种考虑了时变速度的，具有冲击角和导引头视场（FOV）约束的视角成形制导律。相对于相对范围的视角分布首先被构造为三次多项式。期望的冲击角和最大视角表示为视角轮廓中参数的函数。通过在边界条件下求解该参数，可以实现有限视场角下的冲击角约束。而且，导出期望的冲击角的可行区域以确保导引器的锁定状态。通过结合一阶视角动力学和参考视角轮廓，获得具有FOV约束的冲击角控制制导（IACG）定律。拟议的制导律是在不依赖线性参与运动学的情况下得出的，制导过程中的切换逻辑，恒定速度假设和LOS速率信息。此外，所提出的指导技术有助于用户/设计者提前选择可行的冲击角约束而无需调整参数。最后，在现实模型下进行了数值模拟，以验证所提出的制导律的有效性。