Influence of two-loop/three-loop autopilot on precision of guidance and control with glint noise

Glint noise comes to one of the main random error sources for the terminal radar guidance system. In this kind of background, the improvement of impact precision for radar guided missile in the presence of glint noise is studied, from the control system design perspective. With glint noise as its input, noisy model of guidance and control including approximate gimbal seeker dynamics is established. The control system design index is chose within both time and frequency domain, and then the pole placement design procedure with open-loop crossover frequency constraint for typical two-loop and three-loop autopilots is accomplished. The effect of design index on the miss distance of impact is estimated. The results show that when two-loop autopilot is used in the proportional guidance and control system, properly increasing open-loop crossover frequency index, or softly decreasing the system damping index could always lead to more precise impact, and when three-loop autopilot is adopted, enlarging the simple phase-lag element (three-loop autopilot) is the third effective way besides the two ones proposed before.