中文摘要：

研究了同时具有终端角度（攻击角度）和终端时间（攻击时间）约束的制导问题。通过将非线性运动学制导模型中的自变量由导引时间变换为速度方向角，可以利用最小值原理直接推导出一种闭环形式制导律，而不必引入任何的线性化处理。在该制导律的导引下，导弹能够精确击中目标并且精确满足终端时间和角度的约束。为了研究该制导律的可行性，本文定义并分析了若干重要参数的可行域。该闭环制导律及其可行性分析被应用于多弹齐射攻击的两种情况。数字仿真结果验证了所提出方法的有效性。

英文摘要：

A guidance problem with both impact angle and impact time constraints is investigated in this paper. The independent variable in the nonlinear engagement model is changed from the flight time to the heading angle of the missile. Then a new closed-form guidance law can be derived based on the transformed engagement model via the minimum principle without any linear- ization. The proposed guidance law can home a missile to the target with zero miss distance as well as satisfying both of the impact angle and time constraints. Furthermore, to evaluate the feasibility of the proposed law, feasible regions of some key parameters are defined and analyzed. The closed-form guidance law and its feasibility analysis are applied to several salvo attack scenarios. Numerical simulations are performed to demonstrate the effectiveness of our approaches.