考虑捷联导引头最小视场角约束的制导策略

针对高超声速飞行器捷联导引头，提出导引头最小视场角（FOV）约束问题。首先分析了导引头视线角变化规律，指出在攻击固定目标时，导引头最小视场角约束在弹道末段无法被满足，导引头将丢失目标。在此基础上，基于缩短导引头丢失目标距离的目标，提出一种满足导引头最小视场角约束的制导策略。该策略不依赖于末制导律形式，当最小视场角约束无法被满足时，改变原有制导指令，主动改变弹道轨迹以增加弹体视线角，避免超出视场范围。其次，针对飞行器过载约束，设计了制导策略切换点，在到达切换点时该制导策略将结束工作，避免末端过载过大超出约束。通过对比仿真验证了所提出制导策略有效性，能够大幅度减少导引头丢失目标距离，工程上有利于提高末端命中精度。

Guidance strategy considering strapdown seeker minimum field-of-view angle constraint

This article proposes the problem of the minimum Field-of-View (FOV) angle constraint of the strapdown seeker in hypersonic missiles. Analysis of look angle kinematics indicates that the minimum FOV angle constraint cannot be met at the end of the trajectory when the missile attacks stationary targets, leading to target loss by the seeker. Furthermore, to decrease the distance of target loss, we propose a guidance strategy which can be applied to the guidance law with independent orders on longitudinal and lateral channels. When the minimum FOV angle constraint is about to unfulfilled, this strategy sustains the constraint by rolling and longitudinal maneuvering. In addition, a guidance strategy switch point is designed to avoid acceleration exceeding the constraint. The guidance strategy ends when reaching the switch point. Simulation in comparison proves the effectiveness of the proposed guidance strategy in considerably reducing the distance of target loss, which is beneficial to the accuracy improvement of terminal guidance.