在末制导武器备受青睐的背景下,首先,给出了制导系统的基本结构,简单介绍了比例导引律下的制导回路及其特点。其次,在平台式导引头机械结构假设下,为使导引头快速追踪目标,将进动角速率分为线性区、过渡区和非线性区,使用Hermite方法设计了导引头跟踪方案,使导引头角速率平滑过渡。再次,针对这类导引头普遍存在死区-饱和非线性环节的问题,运动描述函数方法,重点分析了引入自动驾驶仪的制导系统稳定性问题。研究表明,该非线性环节对系统相位裕度没有影响,而对幅值裕度略有提高。最后,给出了随剩余末制导时间的减少,制导系统特征根的分布情况以及末制导段最小稳定裕度。

At first, the basic structure of guidance system was given, and guidance system with proportional navigation law was introduced. Secondly, on the assumption that mechanism of dynamic stabilized gyro was adopted, in order to track target quickly, tracking scheme of laser seeker was set in nonlinear, transition and linear zones, and tracking loop of this seeker was designed with Hermite Method, which smoothened proecessing rate of the seeker. Then according to principle of the laser seeker, there was dead-saturation nonlinearity in the guidance loop. With characteristics of guidance system, describing function method was used to research the stability problem while autopilot was introduced into guidance loop. Analysis shows that nonlinearity has no effect on the phase margin, however, it improves magnitude margin. In addition, the change of root locus with time to go for guidance, and the minimal stability margin is given as another base of stability analysis.