用于航磁测量的多旋翼无人机磁干扰测试研究

Research on magnetic interference tests of multi-rotor Unmanned Aerial Vehicle(UAV)intended for aeromagnetic surveying

在无人机航磁测量工作前期,全面评价无人机相关磁干扰源及其特征,可为后期磁力仪安装位置与方式的确定、数据降噪措施的选择等提供依据.本文以多旋翼无人机为例,分别进行了本底磁特征测试、异常部位不同状态下的噪声测试、电机干扰信号的时频分析、以及动态飞行时的干扰影响距离测试和研究.识别出电机、电流为主要干扰源;电流的产生和传输既会改变已有的静态干扰强度,又会产生新的动态震荡噪声;电机旋转所产生的震荡干扰信号是集合了与电机旋转速度、内部转子和定子数量等有函数关系的多频率复合信号;磁力仪所记录的干扰信号强度,随其与干扰源之间距离的增大而衰减.本文测试方法可作为无人机相关磁干扰测试的参考,测试结果可用于指导磁力仪安装和数据降噪.

In the early stage of Unmanned Aerial Vehicle(UAV)aeromagnetic surveying,a comprehensive evaluation of UAV-related magnetic interference sources and characteristics can provide basis support for determining the appropriate installation position and method of the magnetometer,and selecting effective data noise reduction measures.Taking multi-rotor UAV as an example,this paper conducts magnetic characteristics mapping of the UAV,interference testing of abnormal parts under different conditions,time-frequency analysis of motor interference signals,and the interference distance testing during its dynamic flight.According to the research results,it identifies that motor and current are the main interference sources.Generation and transmission of current will not only change the original static interference intensity,but also produce dynamic vibration noise.The vibration signal during the motor rotation is multi-frequency compound interference,and the relationship between different frequencies is related to its rotation speed,the number of rotors and stators.The interference signal intensity recorded by the magnetometer rapidly decays as the distance between it and the interference source increases,and can be ignored beyond a certain distance.The method in this paper can serve as a reference for other UAV interference tests,and the relevant conclusions can also be used to guide the installation of magnetometers and data noise reduction.