Moog Crossbow NAV440 Series - Manual (Page 19)

AV440 User Manual
0131‐01 Rev. F
Page 19 N
7430‐
Chapter 2. 440 Series Functions
This chapter provides an overview of the hardware and software systems of the 440 Series unit, and the functions
provided.
• 440 Series System, page 19
• Software Structure, page 20
•
t Coordinate System 440 Series Defaul
•
, page 22
IMU440 , page 23
• , page VG440 (Vertical Gyroscope) 25
• AHRS440 Function, page 27
•
NAV440 Function, page 30
440 Series System
The 440 Series 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. The system integrates advanced
MEMS inertial gyros and accelerometers, embedded or optional remote 3‐axis magnetometer, a SAASM or C/A code
GPS rece r
homelan
iver, and 10/100 Ethernet interface in a fully sealed enclosure for tactical vehicle operating in combat o
d security environments.
Figure 1 below shows the 440 Series hardware block diagram. At the core of the 440 Series is a rugged 6‐DOF
(Degrees of Freedom) MEMS inertial sensor cluster that is common across all members of the 440 Series . The 6‐
DOF MEMS inertial sensor cluster includes three axes of MEMS angular rate sensing and three axes of MEMS linear
acceleration sensing. These sensors are based on rugged, field proven silicon bulk micromachining technology.
Each sensor within the cluster is individually factory calibrated using Moog Crossbow ’s automated manufacturing
rocess. p
Configuring GNAV540 Functions
Base on d the User Behavior settings, the Series 440 unit can be configured to fulfill various functions.
1. Using only the calibrated sensor data, the Series 440 unit functions as an Inertial Measurement Unit (IMU)
to output angular rates and accelerations.
2. Incorporating the gyroscope and accelerometer data with the EKF, the Series 440 unit 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 Series 440 unit 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 Series 440 unit 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 WAAS GPS receiver can be integrated with the unit
and configured to override the internal receiver.