某型无人机系统雷电脉冲磁场效应

Lightning pulse magnetic field effects on UAV system

为检验雷电脉冲磁场辐射环境下无人机系统的安全可靠性,以某型无人机为试验对象,利用亥姆霍兹线圈和雷电浪涌发生器模拟雷电脉冲磁场,开展了无人机雷电脉冲磁场效应试验。实验结果表明,GB50057-94推荐的8/20μs雷电脉冲磁场不会干扰无人机通信而导致数据链失锁,但是机载三轴磁航向传感器受磁场干扰严重,产生零点漂移并造成已知方向上读数偏差,且放电极性决定航向角变化趋势。经过机理分析发现,在线性工作区间内磁航向传感器能够利用各向异性磁阻效应引起电阻阻值变化的规律正常工作,但高峰值雷电脉冲磁场会导致坡莫合金电阻内部磁畴排列紊乱而出现磁化,改变了传感器磁敏感度以及输出特性,且只出现在磁敏感方向上。

In order to test the safety and reliability of the Unmanned Aerial vehicle(UAV)system under the environment of lightning pulse magnetic field,a certain type of UAV was regarded as the test object.Lightning pulse magnetic field was simulated using the Helmholtz coil and the lightning surge generator.The experimental result shows that the lightning pulse magnetic field of 8/20μs as recommended in the national standard GB50057-94 does not interfere with communication to cause the data link unlock.But three axial magnetic heading sensor is interfered seriously to produce drift and cause reading deviation on known direction.Besides,the polarity of discharge determines variation trend of course angle.After a thorough analysis of mechanism,the magnetic heading sensor can work normally in the linear area by using anisotropic magnetoresistance effect's regularly changing the resistance value.But the high peak value lightning pulse magnetic field will lead to permalloy resistance's disordered arrangement of internal magnetic domain and magnetization,which changes the magnetic sensitivity of sensor and output characteristic,and only appears on the magnetic sensitive direction.