Moog Crossbow NAV440 Series - Manual (Page 20)

Page 20
NAV440 User Manual
7430‐0131‐01 Rev. F
Figure 1 440 Series Hardware Block Diagram
6-DOF Sensor
Cluster
X / Y / Z
Gyros
X / Y / Z
Accelerometers 16-BIT
A/D
High-Speed
Sampling &
DSP
+
Sensor
Compensation
+
Navigation &
Attitude
RS-232
(A Port)
System Digital Outputs and Inputs
(Pins 1,2)
Moog Crossbow Serial Protocol
X / Y / Z Acceleration
Roll / Pitch / Yaw Rate
X / Y / Z Magnetic Fields (NAV/AHRS only)
Roll / Pitch / Yaw Angle
Position / Velocity (NAV only) Sensor
Temperatures
XY / Z
Programmable
XYZ
Programmable
X / Y / Z
Magnetometers
GPS Receiver
(WAAS)
NAV only GPS Antenna
NAV only
RS-232
(B Port)
Optional use port (Pins 7,8)
External GPS Input (VG/AHRS)
RS-232
(B Port)
Internal GPS Output
(NAV)
Software Structure
Figure2below shows the software block diagram. The 6‐DOF inertial sensor cluster data is fed into a high speed
100Hz signal processing chain. These 6‐DOF signals pass through one or more of the processing blocks and these
signals are converted into output measurement data as shown. Measurement data packets are available at fixed
continuous output rates or on a polled basis. The type of measurement data packets available depends on the unit
type according to the software block diagram and. Aiding sensor data is used by an Extended Kalman Filter (EKF)
for drift correction. Built‐In‐Test and Status data is available in the measurement packet or via the special Status
Packet T0.
As shown in Figure2, the 440 Series has a 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 440 Series architecture as it
allows the 440 Series to work in a wide range of commercial applications by setting specific functions of the 440
Series .