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ID:51905210
大小:6.46 MB
页数:57页
时间:2020-03-18
《基于磁调制原理的正交磁通门技术研究.pdf》由会员上传分享,免费在线阅读,更多相关内容在应用文档-天天文库。
1、摘要在电磁测量领域中,弱磁测量是最基础也是最重要的。而在弱磁测量中最为实用的磁测仪器便是磁通门。『F交型磁通门以其测量范围广,分辨率高,对测量环境要求低等优点被广泛应用于导航、指南、金属探测和勘探领域。在它的正常范围内既可以有效测量地球磁场,同时也能够解决低于地球磁力105倍的磁场测量问题。随着磁材料的进一步发展,研究『F交型磁通门具有很强的现实意义。在论文工作中,从磁调制以及磁通门的原理出发,采用三折线法近似等效铁芯的磁滞回线,将探头输出的各次谐波按傅里叶级数展开以及一阶泰勒级数近似的方法推导出各次谐波与被测磁场的关系。
2、在磁通门具体设计上,以简单、可靠为出发点,选择北冶生产的高初始磁导率、低矫顽力的软磁材料(精密合金S1J81A)做铁芯探头,采用300Hz、峰峰值为10V的方波做激励信号。解调方式选择相敏检波中的二次谐波法解调信号,闭环方式选择短路电流法将输出信号反馈到检测线圈当中,从而得到一个与被测磁场成正比的稳定电信号来有效的表征被测磁场强度。通过由Labview编程的频谱分析仪对实验结果进行分析,本文设计的J下交型磁通门的噪声水平在283.6pT/4Hz@1Hz,非线性度小于2%。关键词:弱磁测量;正交型磁通门;相敏检波;短路电流法
3、AbstractlheweakmagneticmeasurementISthemostbasicandimportantprobleminthefieldofelectromagneticmeasuring.Andthefluxgateisthemostpracticalinstrumentsinweakmagneticmeasurement.OrthogonalFluxgatesiswidelyusedinnavigation,guidance,metaldetectionandexplorationfieldsfori
4、tswidemeasuringrange,highresolution,andlowenvironmentalrequirementsforthemeasurement.Withinitsnormalrange,itcaneffectivelymeasuretheearth’Smagneticfield,andCansolvemeasurementproblemswho’Smagneticis105timeslowerthantheearth’S.Withthefurtherdevelopmentofmagneticmat
5、erials,researchesofOrthogonalFluxgateshavegreatpracticalsignificance.Intheworkofthispaper,beginningwitlldiscussionoftheprincipleofmagneticfluxmodulationanddoors,itemploysthreelinedrawingmethodtoapproximateequivalenttocorehysteresisloop,translatestheprobeoutputtoea
6、chharmonicbyFourierseriesexpansion,appliesfirstorderTaylorseriesapproximationtoderivetherelationshipbetweeneachharmonicandthemeasuredmagneticfield.Withtheconceptofsimpleandreliable,productionwithhighinitialpermeability,lowcoercivityofsoftmagneticmaterials(Precisio
7、nAlloyS1J81A)ofBeiye’Sisselectedascoreprobe,squarewavewithfrequencyof300Hzandpeakvalueof10Visadoptedasexcitationsignalindesignofthefluxgate.Phase-sensitivedetectionofthesecondharmoniclawisselectedtodemodulatesignal,feedbackoftheoutputtothedetectioncoilisperformedb
8、ytheclosedloopmodeselectionshort—currentlaw,andthenastableelectricalsignalproportionaltothemeasuredmagneticfieldisobtainedtoeffectivelycharacterizethema
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