Instruction Manual

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GNAV540UserManual
7430‐0808‐01Rev.B
Page23
Figure2GNAV540SoftwareBlockDiagram
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.
X / Y / Z Body
Accelerometers
6-
DOF Sensor Cluster
Sensor
Calibration
Axes Rotation

GPS Data
Internal/External
Kalman Filter and Dynamic State Model
Integration to 100 Hz
V
elocity, GPS
Position Output
Hard/Soft Iron
Calibration
UseMags

X / Y / Z
Magnetometers
NAV/AHRS only
IMU
-

Scaled Packets
(S0,S1,S2)
All Units
NAV/AHRS/VG/IMU
Gravity Reference
Turn Rate
(Internal
Computation)
Free Integrate
TurnSwitch
Threshold
UseGPS
Stationary Yaw
Lock
X / Y / Z Body
Rates
100Hz
Signal
Proc.
Chain
Extended Kalman Filter (EKF)
Drift Correction Module
V
G/AHRS
–
A
ngle
Packets
(A0,A1,A2)
NAV/AHRS/VG
NAV
-
NavPackets
NAV/AHRS/VG

Integration to
Attitude
Unit Settings & Profile*

Communication Settings
Axes Orientation
Low Pass Filtering
Free Integrate
UseGPS
UseMags
TurnSwitchThreshold
DynamicMotion
Restart On Overange

Dynamic Motion
Programmable BIT Alerts

Aiding Sensors
Built In Test
& Status
Data
A
vailable to
User
Measurement
Data Available to
User (Fixed Rate

or Polled)
Status Packet (T0)
(N0,N1,N2, N3)
TheGNAV540featuresincludesensorsusedintheEKFforthedriftcorrectionofthe6‐DOFinertialsensorcluster
A3‐axismagnetometerandaGPSreceiverareusedforcorrectingthedriftonyaw/headingangle,increasingthe
accuracyoftheattitudeestimationbyincorporatingthesesensorsignalsintotheEKFandprovidinganavigation
solution.Thecommonaidingsensorforthedriftcorrectionfortheattitude(i.e.,rollandpitchonly)isa3‐axis
accelerometer.
Figure3belowillustratestheunitsettingandprofileblock,whichconfiguresthealgorithmtouserandapplication
specificneeds.ThisfeatureisoneofthemorepowerfulfeaturesintheGNAV540architecture,asitallowsthe
GNAV540toworkinawiderangeofcommercialapplicationsbysettingdifferentmodesofoperation.