无人机定位系统辐照干扰失效全过程与机理分析

Failure process and mechanism of irradiation interference in unmanned aerial vehicle positioning system

定位系统是无人机核心单元中的电磁敏感环节,是无人机电磁防护的重点部位。为了分析电磁干扰效应机理与失效过程,以典型自组装无人机定位系统为目标,通过电磁拓扑模型分析干扰耦合方式,分析不同耦合路径下辐照干扰耦合机理和作用机制。采用GPS增强转发系统在电波暗室内为无人机系统提供正常动态工作环境,并依据标准开展微波辐照干扰效应试验,通过无人机系统固件中的日志记录功能,结合地面站监测实时状态,实现无人机定位系统电磁干扰效应全过程动态特征数据记录与故障机理分析。试验结果表明:无人机接收天线耦合干扰主要发生在定位系统最大接收带宽(200 MHz)之内;线缆耦合干扰主要在1 GHz以下的频段内且在171 MHz和511 MHz附近达到最大值;PCB电路耦合干扰主要在1.24 GHz以上频段,耦合电压波动性随着干扰信号频率增加而变强。

Positioning system is the electromagnetic sensitive part in the core unit of unmanned aerial vehicle(UAV)and the key part of UAV electromagnetic protection.To analyze the failure process and mechanism of electromagnetic interference,aiming at the positioning system of typical self-assembled UAV,the radiation coupling path is analyzed by constructing the electromagnetic topology and the radiation interference effects of different coupling paths of UAV positioning system are simulated and analyzed.The GPS enhanced forwarding system is used to provide a normal working environment for the UAV system in the anechoic chamber and the microwave irradiation interference effect experiment is carried out.Through the logging function in the UAV’s firmware,combined with the real-time monitoring data in ground station,the whole process data recording and fault mechanism analysis of the electromagnetic interference of the UAV positioning system are realized.The experimental results show that the coupling interference of the receiving antenna mainly occurs within the maximum receiving bandwidth(200 MHz)of the positioning system;Cable coupling interference mainly occurs in the frequency band below 1 GHz and reaches the maximum near 171 MHz and 511 MHz;The coupling interference of PCB circuit mainly occurs in the frequency band above 1.24 GHz and the fluctuation of coupling voltage becomes stronger with the increase of interference signal frequency.