光纤图像制导导弹导引头框架角分析

 光纤图像制导导弹导引头采取小型化结构,为避免导引过程中发生碰框,需要对导引头框架角进行约束。研究了图像制导导弹在三点法和比例导引法下的需用框架角。结果表明,三点法导引随弹目距离接近需用框架角增大,比例导引法使框架角收敛,由此提出极限框架角时刻,即三点法导引转入比例导引的瞬间。讨论了目标机动对框架角的需求,目标曲线逃逸情况下,单纯的比例导引可能导致追踪过程中导弹框架角发散,由此设计了带有框架角约束的比例导引律。仿真结果表明,加入框架角约束项,能够较为有效地将框架角限制在一个相对较小的波动范围,实现框架角的约束,适用于追踪曲线运动目标。

Frame angle design of image guided aircraft

In the design of the image guided bomb, the frame angle varies in a limited range in order to avoid hitting the frame of the miniaturization seeker. Therefore the guidance with a limited frame angle range of the image guided aircraft should be studied. The frame angle increases with the decrease of the line-of-sight distance in the three-point guidance, but it is the other way round using the proportional guidance. Therefore, the maximum frame angle is reached when changing the guidance law from the three-point guidance to the proportional guidance. In this paper, a modified proportional navigation is put forward to decrease the frame angle when following a curve escaping target. The frame angle can thus be limited in a small range according to the simulation results.