基于NOFRF的脉冲式雷达快速故障诊断方法

Fast Fault Diagnosis Method of Pulse Radar Based on Nonlinear Output Frequency Response Function Model

脉冲式雷达在传统测试中需要通过大量的性能参数测试,来判断雷达是否处于正常状态,测试过程步骤复杂且耗时长。为克服脉冲式雷达传统测试中存在的缺点,提出了一种新型的采用非线性输出频域响应函数(Nonlinear Output Fre-quency Response Function,NOFRF)模型的快速故障诊断方法。首先利用脉冲式雷达的发射机在发射射频信号时会通过收发开关将一小部分射频信号送入接收机的特点,将雷达予调脉冲信号和雷达接收机检波器的视频脉冲信号分别看作雷达系统的输入激励和输出响应,因此可将整个雷达系统看作是一个具有输入输出端口的黑匣子,便于根据NOFRF模型对其进行建模。其次采用NOFRF的快速自适应辨识算法对雷达的各阶NOFRF核进行辨识,然后以各阶NOFRF核的功率积累量作为故障特征量,对雷达的健康状态进行快速识别。通过某型武器系统脉冲式雷达机的故障诊断验证,证明所提方法的有效性。

A mass of performance parameters need to be tested to estimate whether or not the pulse radar is at normal state in the conventional test. The procedure of conventional test is complex and time - consuming. To over- come the defects, a novel and fast fault diagnosis method was proposed based on the model of nonlinear output fre- quency response function （ NOFRF）. Firstly, the characteristic that a fraction of radio - frequency signal of the trans- mitter of pulse radar leaks to radar receiver was utilized in the method. The pulse signal of the pre - modulator and the video frequency pulse signal of the radiodetector were considered as the input excitation and output response of the radar system, so the whole radar system can be looked as ＂black box＂ with input and output ports, which can be modeled with NOFRF in a convenient way. Secondly, every order NOFRF of the radar system was identified using fast adaptive identification algorithm. The power acumulant of every order NOFRF was employed as fault feature so as to identify the health status of the radar system. The fault diagnosis results of the pulse radar of a certain type of weapon system validate the proposed method.