全捷联成像导引头隔离度与寄生回路稳定性研究

针对全捷联成像导引头视线角速度提取中隔离度及其带来的寄生回路稳定性问题，首先建立了考虑惯性测量装置和捷联探测器动力学的视线角速度提取模型并进行了简化。选取传感器动力学、信号处理延时、刻度尺为主要误差源，对由其造成的视线角速度隔离度幅值及相角变化规律进行了分析。进一步通过构建相应对应全捷联导引头隔离度寄生回路模型，计算了寄生回路稳定域并给出允许误差边界。分析结论表明，视线角速度提取过程中存在的以上误差将带来远较平台导引头大的隔离度问题，并导致寄生回路失稳，因此需在信号处理过程中进行修正。

Disturbance rejection rate and parasitical loop stability for strapdown imaging seeker

The problems on disturbance rejection rate of strapdown imaging seeker and the stability of disturbance rejection rate parasitical loop were analyzed in this paper. Firstly, two calculation methods of line of sight (LOS) rate were given based on the information from seeker and inertial measurement unit (IMU). The calculation model got simplified in order to analyze the influence to disturbance rejection rate from different disturbance items. Then the magnitude and phase of disturbance rejection rate caused by the aerodynamic model, time delays of signals and graduate scales were analyzed, especially in the low frequency bandwidth. Finally, the disturbance rejection rate parasitical loop model based on strapdown seeker was derived. Through discussing the stability zones of parasitical loop, the permitted maximum values for different disturbances were given. The results present that disturbance sources mention above will cause the terrible disturbance rejection rate problem and make the parasitical loop become unstable, so it is necessary to rectify them when calculating LOS rate.