LORD 3DM-GX4-45 User manual

LORD USERMANUAL
3DM-GX4-45™
GPS-Aided Inertial Navigation System (GPS/INS)

© 2014 LORDCorporation
MicroStrain®Sensing Systems
459 Hurricane Lane
Suite 102
Williston, VT 05495
United States of America
Phone: [phone]
Fax: [phone]
http://www.microstrain.com
[e-mail]
[e-mail]
Copyright © 2014 LORD Corporation
3DM®, 3DM-DH®, 3DM-DH3™, 3DM-GX1®, 3DM-GX2®, 3DM-GX3®, 3DM-GX4-15™, 3DM-GX4-25™, 3DM-GX4-45™,
3DM-GX4™, 3DM-RQ1™, AIFP®, Ask Us How™, Bolt-Link®, DEMOD-DC®, DVRT®, DVRT-Link™, EH-Link®,
EmbedSense®, ENV-Link™, FAS-A®, G-Link®, G-Link2™, HS-Link®, IEPE-Link™, Inertia-Link®, Little Sensors, Big Ideas.®,
Live Connect™, LXRS®, MathEngine®, MicroStrain®, MVEH™, MXRS®, Node Commander®, PVEH™, RHT-Link®, RTD-
Link™, SensorCloud™, SG-Link®, Shock-Link™, Strain Wizard®, TC-Link®, Torque-Link™, V-Link®, Watt-Link™, Wireless
Simplicity, Hardwired Reliability™, and WSDA®are trademarks of LORD Corporation.
Document 8500-0041 Revision D
Subject to change without notice.

3DM-GX4-45™Inertial Navigation System User Manual
Table of Contents
1. System Overview 7
2. Sensor Overview 8
2.1 Components 9
2.2 Interface and Indicators 10
3. Basic Setup and Operations 11
3.1 Software Installation 12
3.2 System Connections 13
3.3 Software Interface 14
3.3.1 Interactive Help Menu 14
3.4 Sensor Communication 15
3.5 GPS Link 16
3.6 Sensor Settings 16
3.6.1 Saving Configurations 18
3.7 Data Monitoring and Recording 19
3.8 Viewing Data 22
4. Sensor Measurements 23
4.1 Direct Sensor Measurements (IMU Outputs) 24
4.2 Global Positioning System (GPS) Outputs 26
4.3 Computed Outputs (Estimation Filter) 28
4.4 Sensor Reference Frames 31
4.4.1 Geodetic Frame 31
4.4.2 NorthEast Down (NED) Frame 32

3DM-GX4-45™Inertial Navigation System User Manual
4.4.3 Sensor Frame 33
4.4.4 Platform Frame 34
5. Performance Optimization 36
5.1 Magnetometer Calibration 36
5.2 Gyroscope Bias 39
5.3 Heading Drift and Compensation 40
5.4 Angular Rate and Acceleration Limits 41
5.5 Bandwidth 41
5.6 Platform Frame Transformation 41
5.7 GPSParameters 41
5.8 GPS Antenna Offset 42
5.9 Vehicle Dynamics Mode 43
5.10 Estimation Filter Operation 44
5.11 Estimation Filter Convergence 46
5.11.1 Initial Convergence 46
5.11.2 Bias Convergence 46
5.11.3 Output Uncertainty 46
5.12 Vibration Isolation 47
5.13 IMU Sensor Calibration 47
5.14 Temperature Compensation 47
6. Sensor Installation 48
6.1 Sensor Mounting 48
6.2 GPS Antenna Installation 49
7. OEMSystemIntegration 50

3DM-GX4-45™Inertial Navigation System User Manual
7.1 DataCommunications Protocol (DCP) 50
7.1.1 Packet Builder 51
7.1.2 Sensor Direct Mode 52
7.1.3 GPSDirect Mode 53
7.2 Sensor Wiring 54
7.3 Alternate GPS Equipment 55
7.3.1 GPSExternal Receiver 55
7.4 Sampling on Start-up 57
7.5 Connecting to a Datalogger 58
7.6 Using Wireless Adapters 58
8. Troubleshooting 59
8.1 Troubleshooting Guide 59
8.2 Repair and Calibration 64
8.3 Technical Support 65
9. Maintenance 66
10. Parts and Configurations 67
10.1 Standard Configurations 67
10.2 Accessories 69
10.3 Sales Support 70
11. Specifications 71
12. Safety Information 73
13. Addendum 74
13.1 Reference Diagrams 74
13.1.1 Sensor Dimensions and Origin 74

3DM-GX4-45™Inertial Navigation System User Manual
13.1.2 GPSAntennaSpecifications 75
13.1.3 Power Supply Specifications (RS232 kits only) 76
13.1.4 Communication and Power Cables 77
13.2 Reference Documents 78
13.3 Glossary 79

3DM-GX4-45™Inertial Navigation System User Manual System Overview
7
1. System Overview
The LORD MicroStrain®3DM-GX4™family of industrial grade inertial sensors provides a wide
range of triaxial orientation measurements and computed navigation solutions. In all models, the
Inertial Measurement Unit (IMU) includes direct measurement of acceleration, angular rate, and
atmospheric pressure. Sensor measurements are processed through an Extended or Adaptive
Kalman Filter (EKF/AKF) to produce high accuracy computed outputs. The computed outputs
vary between models and include: pitch and roll in the 3DM-GX4-15™IMU/VRU model, the full
attitude solution (pitch, roll, and yaw) in the 3DM- GX4- 25™AHRS model, and the full PVA
(position, velocity and attitude) solution in the 3DM-GX4-45™and 3DM-RQ1™GPS/INS models.
The Kalman filter provide EKF technologies to compensate for magnetic and linear acceleration
anomalies, as applicable to the model. It also provides sensor bias tracking, auto-zero update
options (ZUPT), and user adjustable sensor noise factors. All sensors are fully temperature
compensated and calibrated over the full operating temperature range
The use of Micro-Electro-Mechanical System (MEMS) technology allows for small, lightweight
devices. Sensors are integrated into customer systems using serial communication protocols such
as RS232 and USB. The LORD MicroStrain®MIP™Monitor software can be used for device
configuration, real time measurement monitoring, and data recording. The LORD MicroStrain®
MIP™Data Communications Protocol that is used to communicate with LORD MicroStrain ®
inertial sensors is also available for users who want to develop customized software solutions.
Because of the unified set of commands across the sensor family, it is easy to migrate code from
one inertial sensor to another.
Common applications of LORD MicroStrain ®inertial sensor products include vehicle health
monitoring, platform stabilization, down- hole and drilling operations, and inertial navigation
systems such as unmanned air and ground vehicles and personal navigation systems.

3DM-GX4-45™Inertial Navigation System User Manual Sensor Overview
8
2. Sensor Overview
The 3DM-GX4-45™is a high-performance, miniature, Inertial Aided GPSNavigation System
(GPS/INS) that combines micro inertial sensors and a high- sensitivity embedded Global
Positioning System (GPS) receiver for use in a wide range of industrial grade applications such as
unmanned vehicle navigation, robotic control, platform stabilization, motion tracking and analysis,
vehicle health monitoring, and device aiming.
The 3DM-GX4-45™utilizes the strengths of integrated multi-axis gyroscopes, accelerometers,
and magnetometers in combination with GPS, temperature, and pressure readings to provide high
accuracy position, velocity, attitude (including heading), and inertial measurements. Each of the
integrated sensors is especially good at certain tasks, and it is the weighted combination of their
outputs that provides the best estimations for position, velocity and attitude . All sensor
measurements are temperature compensated and are mathematically aligned to an orthogonal
coordinate system. The combination of sensors, environmental compensation and dual on-board
processing with an Extended Kalman Filter (EKF) allow the 3DM-GX4-45™to perform well in a
wide variety of applications that require low noise, drift, gain, and offset errors. Uncertainty
monitoring, scale factor estimation, and bias estimation outputs are available, and settings for
sensor filtering, sensor noise, sensor bias, and more offer many adjustments for specific
application needs.
The 3DM- GX4- 45 ™communicates through a serial connection and is monitored by a host
computer. A detachable GPS antenna is plugged into the sensor and positioned with unobstructed
line of sight to the sky to obtain GPS satellite links. Sensor measurements and computed outputs
can be viewed and recorded with the LORD MicroStrain®MIP™Monitor software that is provided
with system starter kits, and also available as a free download from the LORD MicroStrain®
website. Alternatively, users can write custom software with the LORD MicroStrain®open source
data communication protocol. The data is time- aligned and available by either polling or
continuous stream.
Figure 1 - 3DM-GX4-45™Sensor

3DM-GX4-45™Inertial Navigation System User Manual Sensor Overview
9
2.1 Components
The 3DM -GX4 -45™can be purchased by itself or in a starter kit that includes everything
needed to begin using it. The starter kits include the 3DM-GX4-45™inertial sensor, a serial
communications cable (either RS232 or USB), a power supply with country plug adapter
(RS232 kits only), an external GPS antenna with a three meter cable, a non-magnetic GPS
antenna adapter cable, and all software, drivers, and documentation. This manual covers all
items included in the starter kits. For a complete list of available configurations, accessories,
additional system products and ordering information see Parts and Configurations on page 67.
Item Description Quantity
A3DM-GX4-45™Inertial Sensor 1
BCommunications cable (USB or RS232) 1
CPower supply and country plug adapters (for RS232 only) 1
DGPS antenna with attached cable (3m SMA) 1
EGPS antenna cable adapter (non-magnetic MMCX-to-SMA) 1
-- MIP™Monitor Software Suite 1
-- User Manual, Quick Start Guide and Calibration Certificate 1
Table 1 - Components List

3DM-GX4-45™Inertial Navigation System User Manual Sensor Overview
10
2.2 Interface and Indicators
The 3DM-GX4-45™sensor interfaces include a dual use communications and power input
connector and a GPS antenna port. The sensor is mounted using the mounting and alignment
holes as needed (see Sensor Mounting on page 48).
The indicators on the 3DM - GX4 - 45 ™include a device status indicator and the device
information label. Table 2 - Indicator Behaviors describes the basic status indicator behavior.
The device information label includes the sensor frame diagram (axis orientation) which will be
critical during device installation (see Sensor Frame on page 33).
Figure 2 - Interface and Indicators
Indicator Behavior Device Status
device status
indicator
OFF no power applied
rapid flash streaming data with no GPS lock
steady blink streaming data with GPS lock
slow pulse idle mode, awaiting commands
Table 2 - Indicator Behaviors