线缆耦合信号实时监测方法

线缆耦合是航电系统电磁干扰问题的主要来源之一,对其进行监测具有重要意义。利用线缆束中的非功能线作为监测线,实现了一种对功能线缆耦合到的干扰信号进行实时监测的方法。由于监测线与被测线具有相似的干扰场分布和布线路径,因此可以抵消二者的未知性和随机性带来的影响。将监测线与被测线视为相同的二端口网络,建立采用ABCD矩阵描述的端口电流相互关系,进而利用传输线理论建立频域解析模型,将其转化为离散时间模型并给出系统的信号流图,为硬件实现提供基础。以一个四芯传输线系统为例对本文方法进行了验证,与实测结果对比,端口电流峰值误差不超过6%,验证了本文方法的有效性和精度。

Real-time monitoring method of cable coupling signal

Cable coupling is one of the most important reasons for electromagnetic compatibility problems in avionics systems.Monitoring the cable coupling effect is of great significance.A method of monitoring the coupling signals on the ports with the spare wire in the cable is introduced.Since the monitoring wire is in the same conditions as the monitored one,the influence of the stochastic routing and field distribution could be counteracted.The monitoring and monitored wires could be regarded as the same two-port system,which could be described with an ABCD matrix.Then the frequency-domain analytical model of this system could be constructed with the transmission line theory.Finally,it could be converted to a discrete-time model and the signal flow graphs of the system could be achieved,which is convenient for the real-time signal processing and hardware realization.A four-wire cable system is taken as the case to validate the method.Compared with the results of measurement,the errors of the current peaks are less than 6％,which is small enough for practical applications.This fact proves that the method is effective and accurate.