Instruction Manual

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GNAV540UserManual
7430‐0808‐01Rev.B
Page21
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Chapter2. GNfAV540Functions
ThischapterprovidesanoverviewofthehardwareandsoftwaresystemsoftheGNAV540unit,andthefunctions
provided
.
•
GNAV540System,page21
• ions
ConfiguringGNAV540Funct
•
,page21
SoftwareStructure,page22
• dinateSystem
GNAV540DefaultCoor
•
,page24
IMUFunction,page25
• Function
VerticalGyroscope(VG)
•
,page26
AHRSFunction,page29
• NAVFunction,page31
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GNAV540System
GNAV540isacompactMEMSbasedGPS/inertialnavigationsystem.ItdeliverscontinuousGPSposition,true
headingandvehicleattitudetrackinginformationforgroundtacticalvehiclesandotherplatformnavigation
applications.ThesystemintegratesadvancedMEMSinertialgyrosandaccelerometers,embeddedoroptional
remote3‐axismagnetometer,aSAASMorC/AcodeGPSreceiver,and10/100Ethernetinterfaceinafullysealed
enclosurefortacticalvehiclesoperatingincombatorhomelandsecurityenvironments.
Figure1onpage22showstheGNAV540systemconfigurationblockdiagram.Tomaximizesystemperformance
andreducecost,theGNAV540providesRS422interfacesforanexternalmagnetometerandaSAASMGPSreceiver:
interfacetopre‐existingequipment.TheinternalGPSreceiveristheRockwellCollinsPolarisLinkcard.
ConfiguringGNAV540Functions
Base ond theUserBehaviorsettings,theGNAV540canbeconfiguredtofulfillvariousfunctions.
1. Usingonlythecalibratedsensordata,theGNAV540functionsasanInertialMeasurementUnit(IMU)to
outputangularratesandaccelerations.
2. IncorporatingthegyroscopeandaccelerometerdatawiththeEKF,theGNAV540canoutputrollandpitch
attitudeinformation,functioningasaVerticalGyroscope(VG)unit.
3. BuildingontheVGfunctionandcombiningmagneticfieldmeasurement,theGNAV540canfunctionasan
AttitudeHeadingReferenceSystem(AHRS):provideaheadingangleestimateinadditiontothe(VG)roll
andpitch.TheGNAV540isprovidedwithaninternalmagnetometer;anexternalmagnetometercanbe
integratedwiththeunitandconfiguredtooverridetheinternalmagnetometer.
4. CombiningGPSsensordataintotheEKF,theGNAV540canprovideacompleteattitudesystem,aswellas
outputting3Dvelocityandpositionmeasurements,therebyfunctioningasaNavigationunit(NAV).An
internalC/AcodeGPSreceiverisprovided;anexternalSAASMGPSreceivercanbeintegratedwiththeunit
andconfiguredtooverridetheinternalreceiver.
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hefollowingsectionsprovidedetailsaboutthesystemlevelandfunctionaloperationsoftheGNAV540.
T
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