Owner's manual
Page32
NAV440UserManual
7430‐0131‐01Rev.F
Setting Def ueaultVal Comments
Orientation
See
Figure4on
page
22.
Toconfiguretheaxisorientation,selectthedesiredmeasurementforeachaxis:
NAV‐VIEW2.2willshowthecorrespondingimageoftheunit,soiteasyto
visualizethemodeofoperation.Referto
OrientationFieldonpage84forthe
twentyfourpossibleorientationsettings.Thedefaultsettingpointsthe
connectorAFT.
Freely
Integrate
OFF
TheFreelyIntegratesettingallowsausertoturntheunitintoafreegyroscope.In
freegyroscopemode,theroll,pitchandyawarecomputedexclusivelyfrom
angularratewithnoKalmanfilterbasedcorrectionsofroll,pitch,andyaw.When
turnedon,thereisnocouplingofaccelerationbasedsignalsintotherolland
pitchormagnetometerbasedsignaltotheyaw.Asaresult,theroll,pitch,and
yawoutputswilldriftroughlylinearlywithtimeduetosensorbias.Forbest
performance,theFreelyIntegratemodeshouldbeusedafterthealgorithmhas
initialized.ThisallowstheKalmanFiltertoestimatetherollandpitchrate
sens
gyro
orbiaspriortoenteringthefreegyroscopemode.Uponexitingthefree
scopemode(OFF),oneoftwobehaviorswilloccur
Iftheunithasbeeninfreelyintegratemodeforlessthansixtyseconds,the
algorithmwillresumeoperationatnormalgainsettings
Iftheunithasbeeninfreelyintegratemodeforgreaterthansixtyseconds,
.
thealgorithmwillforcearesetandreinitializewithhighgainsautomatically
UseGPS ON
TheUseGPSsettingallowsuserstoturnonandofftheGPSfeedback.The
defaultsettingisON.WhenUseGPSisturnedOFF,theunitsbehaviorwillrevert
toAHRS440.
Stationary
YawLock
OFF
ThissettingdefaultstoOFF;itisrecommendedtobeOFFforNAVFunction.The
stationaryyawlockisonlyrecommendedforconsiderationwhentheunitis
operatingwithGPS(UseGPS=ON)andWITHOUTmagnetometerfeedback
UseMags
( =OFF).Stationaryyawlockmaybeappropriateiftheuserplatformis
agroundvehicle.
UseMags ON
TheUseMagssettingallowsuserstoturnonandoffthemagnetometerfeedback
foryaw/headingstabilization.ThedefaultsettingisON..WhenUseMagsis
turnedON,theunitusesthemagneticfieldsensorreadingstostabilizethedrift
,andits
inyaw lavestheyawtothecompassreadingprovidedfromthemagnetic
fieldsensorreadings.
When
UseMagsisturnedOFF,theheading(yaw)anglemeasurementoftheunit
willbeslavedtotheGPSheadingifGPSisavailable,otherwisetheheadingwill
ffthe
driftfeely.Thereasonforthissettingistogivetheuseranabilitytoturno
magnetometerstabilizationwhenseveremagneticdistortionmaybeoccurring.
Thissettingisdesirablewhentheuservehicletemporarilymovesinclose
proximitytoalargeferrousobject.WhentheUseMagsswitchisturnedfromOFF
toON,theunitwillreinitializetheyaw/headinganglewiththecompassreading
providedfromthemagneticfieldsensorreadings.