文献翻译——如何让一个数字罗盘工作？

外文文献资料HowDoesaDigitalCompassWork?AnelectroniccompasssuchastheWayfinderusesapatentedmagneticsensortechnologythatwasfirstdevelopedbyPNI,Inc.fortheU.S.military.Thistechnologyiscalledmagneto-inductiveandisthelargestadvancementincompasstechnologysincethefulxgatewasinvented60yearsago.Themagneto-inductivetechnologyisabletoelectronicallysensethedifferenceintheearthsmagneticfieldfromadisturbancecausedbyexternalelementssuchasferro-magneticmaterialsandthemagneticfieldgeneratedbyautomobileelectricalsystems.WayFinderdigitalcompasshasanembeddedmicrocontrollerthatsubtractstheautomobilemagneticfield(thedistortion)fromthestrongerearthmagneticfieldsresultinginahighlyaccuratecompassreading.CompassInstallationTheperformanceofacompasswillgreatlydependonitsinstallationlocation.Acompassreliesontheearthsmagneticfieldtoprovideheading.Anydistortionsofearthmagneticfieldbyothersourcessuchasacarmassiveironcomponentsshouldbecompensatedforinordertodetermineanaccurateheading.Sourcesofmagneticfieldsinanyautomobileincludepermanentmagnetsmostlyinitsaudiospeakers,motors,electriccurrentsflowinginitswiringeitherdcorac,andferro-magneticmetalssuchassteeloriron.Theinfluenceofthesesourcesofinterferenceonanelectroniccompassaccuracycanbegreatlyreducedbyplacingthecompassfarawayfromthem.Someofthefieldeffectscanbecompensatedbywayofcalibratingthecompassforadefinedlocationintermsofmagneticinterference.However,itisnotalwayspossibletocompensatefortimevaryingmagneticfields;forexample,disturbancesgeneratedbythemotionofmagneticmetals,orunpredictableelectricalcurrentinanearbypowerlines.Magneticshieldingcanbeusedforlargefielddisturbancesfrommotorsoraudiospeakers.Thebestwaytoreducedisturbancesisdistance.Also,neverenclosethecompassinamagneticallyshieldedmetallichousing.CompassTiltErrorsHeadingerrorsduetoatiltdependsomewhatongeographiclocation.Attheequator,tilterrorsarelesscriticalsincetheearthsfieldisstrictlyinthehorizontalplane.ThisprovideslargerXandYreadingsandlittleoftheZcomponentcorrectionnearthemagneticpoles,tilterrorsareextremelyimportantsincethereislessX,YfieldandmoreoftheZcomponent.Tilterrorsarealsodependentontheheading.MagneticFieldDistortionsNearbyFerrousmaterialsisanotherconsiderationforheadinginaccuracy.Sinceheadingisbasedonthedirectionoftheearthshorizontalfieldadigitalcompassmustbeabletomeasurethisfieldwithlesserinfluencefromothernearbymagneticsourcesordisturbances.Theamountofdisturbancedependsonthematerialcontentoftheplatformandconnectorsaswellasferrousobjectsmovingnearby.Whenaferrousobjectisplacedinauniformmagneticfielditwillexertaninfluence.Thisobjectcouldbeasteelboltorbracketnearthecompassoranirondoorlatchclosetothecompass.Thenetresultisacharacteristicdistortion,oranomalytotheearthsmagneticfieldthatisuniquetotheshapeoftheobject.Magneticdistortionscanbecategorizedastwotypeshardironandsoftironeffects.Hardirondistortionsarisefrompermanentmagnetsandmagnetizedironorsteelonthecompassplatform.Thesedistortionswillremainconstantandinafixedlocationrelativetothecompassforallheadingorientations.Hardironeffectsaddaconstantmagnitudefieldcomponentalongeachaxesofthesensoroutput.Tocompensateforhardirondistortionisusuallydonebyrotatingthecompassandplatform(yourcar)inacircleandmeasureenoughpointsonthecircletodeterminethisoffset.Oncefound,the(X,Y)offsetcanbestoredinmemoryandsubtractedfromeveryreading.Thenetresultwillbetoeliminatethehardirondisturbancefromtheheadingcalculation.Thesoftirondistortionarisesfromtheinteractionoftheearthsmagneticfieldandanymagneticallysoftmaterialsurroundingthecompass.Likethehardironmaterials,thesoftmetalsalsodistorttheearthsmagneticfieldlines.Thedifferenceistheamountofdistortionfromthesoftirondependsonthecompassorientation.WhatIsTrueNorth?Itiswellknownthattheearthsmagneticpolesanditsaxisofrotationarenotatthesamegeographicallocation.Theyareabout11.5rotationfromeachother.Thiscreatesadifferencebetweenthetruenorth,orgridnorth,andthemagneticnorth,ordirectionamagneticcompasswillpoint.SimplyitistheangulardifferencebetweenthemagneticandtruenorthexpressedasanEasterlyorWesterlyvariation.Thisdifferenceisdefinedasthevariationangleandisdependentonthecompassshortduration,makingamagneticcompassausefulnavigationtool.CompassCalibrationEachcalibrationmethodisassociatedwithaspecifiedphysicalmovementofthecompassplatforminordertosamplethemagneticspacesurroundingthecompass.TheHardandSoftirondistortionswillvaryfromlocationtolocationwithinthesameplatform.Thecompasshastobemountedpermanentlytoitsplatformtogetavalidcalibration.Aparticularcalibrationisonlyvalidforthatlocationofthecompass.Ifthecompassisre-orientedinthesamelocation,thenanewcalibrationisrequired.Itispossibletouseacompasswithoutanycalibrationiftheneedisonlyforrepeatabilityandnotaccuracy.译文：如何让一个数字罗盘工作？电子罗盘作为寻路者使用磁传感器专利技术，第一个提出开发的资料库的公司为美国军方。这项技术被称为“磁感应”，是在罗盘技术自60年前发明磁通门以来，是世界上最大的进步。在磁感应技术对于电子意义不同的地球磁场扰动所造成的外部因素，如铁磁性材料的磁场产生的汽车电气系统。寻路者数字指南针有一个嵌入式微控制器，补偿汽车磁场（扭曲）从地球磁场较强的领域产生一个高度精确的罗盘读数。罗盘的安装一个指南针的性能，将在很大程度上取决于其安装位置。指南针依赖于地球磁场提供坐标。任何扭曲的地球磁场的其他来源，如汽车大量铁成分应补偿，以便确定一个准确的坐标。磁源域在任何汽车包括永久磁铁像绝大多数的音响喇叭，电机，电流流动的直流或交流电机，和铁磁性金属，如钢或铁。这些影响干扰源使电子罗盘精度大大降低，指南针放置应远离他们。有一些领域的影响可以用得到补偿的方式校准指南针确定的位置以避免磁场干扰。然而，它并非总是可能弥补对于随时间变化的领域；例如，干扰所产生的运动的磁性金属，或不可预知的电流在附近的电力线。磁屏蔽可用于大视场的干扰电机或音响喇叭。最好的办法是减少干扰距离。此外，需要附上指南针在磁屏蔽金属壳体。罗盘倾斜误差坐标错误由于倾斜很大程度上取决于地理位置。在赤道附近，倾斜误差不那么重要，因为地球的磁场是严格的水平面。这提供了较准的X、Y读数和小的部分修正磁极附近，倾斜误差非常重要因为有较少的X、Y场合Z分量。倾斜误差也依赖于坐标。磁场扭曲附近的有色金属材料是另一个需要考虑的使坐标产生误差的原因。由于坐标是基于对地球的水平场方向的数字罗盘必须是能够衡量这一领域，从其他附近的磁场源或干扰的影响较小。干扰的量取决于材料内容的平台和连接器以及黑色的物体附近。当一个黑色对象放置在一个统一的磁场扰动它将会产生影响。这个对象可以是钢螺栓或支架指南针或铁附近门锁