SBG Systems Ellipse AHRS User manual

Ellipse AHRS & INS
High Performance, Miniature Inertial Sensors
Hardware Manual
intro
Document E IPSEHM.1.2
Revision 1.2 - Mar 6, 2017
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Ellipse AHRS & INS – Hardware Manual E IPSEHM.1.2
Revision history
Rev. Date Author Information
1.2 Mar 6, 2017 Alexis Guinamard [E IDOC-39] Split the User manual into hardware manual and other common
documentations (firmware manual and Technical Reference Manual)
[E IDOC-38] Document the automatic 1Hz GGA output on PORT-C for E IPSE-D when
RTCM corrections are enabled
[E IDOC-40] Detail interfaces and ports capabilities depending on Ellipse model
[E IDOC-36] Update support contact details
[E IDOC-32] Updated RS-232/RS-422 electrical specifications
[E IDOC-41] Updated warranty period (2 years)
[E IDOC-42] Clarified automotive dead reckoning performance
[E IDOC-44] Added SP IT cables description
1.1 May 5, 2015 Alexis Guinamard [E IDOC-4] Added WMM2015 and WGS84 gravity model information
[E IDOC-5] Added E IPSE D information (specification, accessories, ...)
[E IDOC-6] Added support for Novatel protocol (GPS aiding)
[E IDOC-8] Added comments about vibration resistance validity
[E IDOC-9] Added pressure sensor specification
[E IDOC-12] Fixed Gyro angular random walk unit
[E IDOC-13] Fixed IP-68 definition
[E IDOC-14] Fixed Missing Sync Out Description
[E IDOC-16] Added official support for additional output interfaces PORT C and PORT E
[E IDOC-21] Added accessories weights when available
1 Oct 7, 2014 Alexis Guinamard First public version
PRE2 Aug 25, 2014 Alexis Guinamard Second pre-version of this document
PRE1 Mar 6, 2014 Alexis Guinamard First pre-version of this document
© 2007 – 2017, SBG Systems SAS. All rights reserved. Information in this document is subject to change
without notice. Copy or redistribution of this document is forbidden without express authorization of SBG
Systems.
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Ellipse AHRS & INS – Hardware Manual E IPSEHM.1.2
Index
Terminology...........................................................................................................................................6
1. Introduction........................................................................................................................................ 7
1.1. Ellipse Overview........................................................................................................................................... 7
1.2. Inertial measurement unit......................................................................................................................... 8
1.2.1. Accelerometers......................................................................................................................................................................... 8
1.2.2. Gyroscopes................................................................................................................................................................................ 9
1.3. Aiding sensors........................................................................................................................................... 10
1.3.1. Internal Magnetometers......................................................................................................................................................... 10
1.3.2. Ellipse-N internal GNSS receiver............................................................................................................................................. 11
1.3.3. Ellipse-D internal GNSS receiver............................................................................................................................................. 11
1.3.4. Internal barometric altimeter................................................................................................................................................. 12
1.3.5. External sensors...................................................................................................................................................................... 12
1.3.5.1. Third party GNSS receiver.............................................................................................................................................. 12
1.3.5.2. Odometer....................................................................................................................................................................... 12
1.4. System Performance................................................................................................................................. 13
1.4.1. Ellipse-A orientation performance.......................................................................................................................................... 13
1.4.1.1. Orientation specifications............................................................................................................................................... 13
1.4.2. Ellipse-E/ N orientation and navigation performance.......................................................................................................... 13
1.4.2.1. and applications............................................................................................................................................................ 13
1.4.2.2. Marine & Subsea applications....................................................................................................................................... 13
1.4.2.3. Airborne applications.................................................................................................................................................... 14
1.4.3. Ellipse-D orientation and navigation performance............................................................................................................... 14
1.4.3.1. and applications........................................................................................................................................................... 14
1.4.3.2. Marine & Subsea applications....................................................................................................................................... 15
1.4.3.3. Airborne applications..................................................................................................................................................... 15
1.4.4. Heave performance................................................................................................................................................................. 15
2. Mechanical and Electrical specifications...........................................................................................16
2.1. Mechanical specifications......................................................................................................................... 16
2.1.1. Overview................................................................................................................................................................................... 16
2.1.2. Specifications.......................................................................................................................................................................... 16
2.1.3. Device mechanical alignment................................................................................................................................................. 17
2.1.4. Origin of measurements......................................................................................................................................................... 17
2.1.5. Device labels............................................................................................................................................................................ 17
2.1.6. Ellipse-A mechanical outline.................................................................................................................................................. 18
2.1.6.1. Front view....................................................................................................................................................................... 18
2.1.6.2. Top view......................................................................................................................................................................... 18
2.1.6.3. Right view...................................................................................................................................................................... 19
2.1.6.4. Bottom view................................................................................................................................................................... 19
2.1.7. Ellipse-E mechanical outline................................................................................................................................................... 20
2.1.7.1. Front view....................................................................................................................................................................... 20
2.1.7.2. Top view......................................................................................................................................................................... 20
2.1.7.3. Right view....................................................................................................................................................................... 21
2.1.7.4. Bottom view................................................................................................................................................................... 21
2.1.8. Ellipse-N mechanical outline................................................................................................................................................. 22
2.1.8.1. Front view...................................................................................................................................................................... 22
2.1.8.2. Top view......................................................................................................................................................................... 22
2.1.8.3. Right view..................................................................................................................................................................... 23
2.1.8.4. Bottom view.................................................................................................................................................................. 23
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2.1.9. Ellipse-D mechanical outline.................................................................................................................................................. 24
2.1.9.1. Front view....................................................................................................................................................................... 24
2.1.9.2. Top view......................................................................................................................................................................... 24
2.1.9.3. Right view...................................................................................................................................................................... 25
2.1.9.4. Bottom view.................................................................................................................................................................. 25
2.2. Electrical specifications........................................................................................................................... 26
2.2.1. Ellipse-A without GPS aiding................................................................................................................................................. 26
2.2.2. Ellipse-E with external aiding only........................................................................................................................................ 26
2.2.3. Ellipse-N with embedded GNSS............................................................................................................................................ 26
2.2.4. Ellipse-D with embedded dual antenna GNSS..................................................................................................................... 27
2.2.5. Main connector....................................................................................................................................................................... 27
2.2.5.1. Connector specifications............................................................................................................................................... 27
2.2.5.2. Connector pin out for Ellipse B1 versions.................................................................................................................... 28
2.2.5.3. Connector pin out for Ellipse B2 versions.................................................................................................................... 28
2.2.6. Auxiliary connector (Ellipse-E).............................................................................................................................................. 28
2.2.6.1. Connector specifications.............................................................................................................................................. 28
2.2.6.2. Connector pin out......................................................................................................................................................... 29
2.2.7. Auxiliary connector (Ellipse-D)............................................................................................................................................... 29
2.2.7.1. Connector specifications............................................................................................................................................... 29
2.2.7.2. Connector pin out.......................................................................................................................................................... 29
2.2.8. Electrical specifications......................................................................................................................................................... 30
2.2.8.1. Electrical specifications................................................................................................................................................ 30
2.2.9. GPS antenna connector (Ellipse-N and D)............................................................................................................................. 31
2.2.9.1. GPS antenna advice for Ellipse-N.................................................................................................................................. 31
2.2.9.2. GPS antenna advice for Ellipse-D................................................................................................................................ 32
3. Interfaces specifications..................................................................................................................33
3.1. Overview.................................................................................................................................................... 33
3.1.1. Interfaces availability and multiplexing................................................................................................................................. 33
3.2. Serial interfaces....................................................................................................................................... 34
3.2.1. Supported protocols............................................................................................................................................................... 34
3.2.2. Ports functions Mapping....................................................................................................................................................... 34
3.2.2.1. Ellipse A version............................................................................................................................................................ 34
3.2.2.2. Ellipse E version............................................................................................................................................................ 35
3.2.2.3. Ellipse N........................................................................................................................................................................ 35
3.2.2.4. Ellipse D version............................................................................................................................................................ 35
3.3. CAN 2.0 A/B interface............................................................................................................................. 36
4. Important notices............................................................................................................................37
4.1. Absolute maximum ratings...................................................................................................................... 37
4.2. Maintenance............................................................................................................................................. 37
4.2.1. Cleaning................................................................................................................................................................................... 37
4.3. Support.................................................................................................................................................... 38
4.4. Warranty, liability and return procedure................................................................................................. 38
5. Appendix A: Ordering codes and Accessories...................................................................................39
5.1. Ellipse ordering codes............................................................................................................................... 39
5.2. Development kits..................................................................................................................................... 39
5.2.1. DK-E I-[B, ]........................................................................................................................................................................... 39
5.2.2. DK-E I-D................................................................................................................................................................................ 40
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5.3. Cables....................................................................................................................................................... 40
5.3.1. CA-E I-USB-3M...................................................................................................................................................................... 40
5.3.2. CA-E I-D-USB-3M................................................................................................................................................................. 40
5.3.3. CA-PSU-12V-1.5M.................................................................................................................................................................. 40
5.3.4. CA-E I-RS232-CAN-3M.......................................................................................................................................................... 41
5.3.5. CA-E I-RS422-3M................................................................................................................................................................. 42
5.3.6. CA-E I-SP IT-RS232-DB-0.5M............................................................................................................................................. 43
5.3.7. CA-E I-SP IT-CAN-DB-0.5M.................................................................................................................................................. 43
5.3.8. CA-E I-SP IT-RS232-DB-0.5M............................................................................................................................................. 44
5.4. GNSS antennas........................................................................................................................................ 45
5.4.1. ANT-TA -TW-32-2410-00-3000 and ANT-TA -TW-32-2710-00-3000................................................................................... 45
5.4.1.1. Performance specifications........................................................................................................................................... 45
5.4.1.2. Mechanical drawing...................................................................................................................................................... 45
5.4.2. ANT-ACM-G5ANT-1A196MNS-1............................................................................................................................................. 46
5.4.2.1. Performance specifications.......................................................................................................................................... 46
5.4.2.2. Mechanical drawing..................................................................................................................................................... 46
5.4.3. High performance GNSS antennas....................................................................................................................................... 47
5.4.3.1. TNC Cables..................................................................................................................................................................... 47
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Terminology
ADC: Analog to Digital Converter
AHRS: Attitude and Heading Reference System
CAN (Bus): Controller Area Network
DHCP: Dynamic Host Configuration Protocol
DV : Doppler Velocity og
EKF: Extended Kalman Filter
EEPROM: Electrically-Erasable Programmable Read-Only Memory
FIR: Finite Impulse Response (filter)
FTP: File Transfer Protocol
FS: Full Scale
FOG: Fiber Optic Gyroscope
GNSS: Global Navigation Satellite System
GPS: Global Positioning System
IIR: Infinite Impulse Response (filter)
IMU: Inertial Measurement Unit
INS: Inertial Navigation System
IP: Internet Protocol
B : ong Baseline
MAC (address): Media Access Control
MEMS: Micro Electro-Mechanical Systems
NED: North East Down (coordinate frame)
NA: Not applicable
NMEA (NMEA 0183): National Marine Electronics Association (standardized communication protocol)
PPS: Pulse Per Second (signal)
RAM: Random Access Memory
RMA: Return Merchandize Authorization
RMS: Root Mean Square
RTCM: Radio Technical Commission for Maritime Services (Protocol)
RTK: Real Time Kinematics
SI: International System of Units
TBD: To Be Defined
TCP: Transmission Control Protocol
UDP: User Datagram Protocol
UTC: Coordinated Universal Time
USB : Ultra Short Base ine
VRE: Vibration Rectification Error
WGS84: World Geodetic System 1984
WMM: World Magnetic Model
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Ellipse AHRS & INS – Hardware Manual E IPSEHM.1.2
1. Introduction
Ellipse series is a line of miniature, high-performance MEMS based
Inertial Systems which achieve exceptional orientation and
navigation performance in a miniature and affordable package. It
includes an Inertial Measurement Unit (IMU) and runs an on-board
enhanced Extended Kalman Filter (EKF). The Ellipse line is divided
in a comprehensive set of sensors:
●The Ellipse-A version is an attitude and Heading Reference
System (AHRS), providing accurate orientation in dynamic
conditions.
●The Ellipse-E, N and D models are Inertial Navigation
Systems (INS), providing both orientation and navigation
data. The use of GNSS data or other aiding equipment such
as odometer or internal barometric sensor can be used to
provide accurate navigation data, but also to improve
orientation accuracy:
●The Ellipse-E model can be connected to an external GNSS receiver.
●The Ellipse-N model embeds an industrial GNSS receiver in a miniature package.
●The Ellipse-D embeds a survey grade GNSS receiver with dual antenna heading for excellent
heading performance in magnetic denied environments. Targeting demanding application, it is
also capable of post-processing, thanks to the internal GNSS raw data output.
To achieve the best performance in every project, specific error models have been implemented to meet
applications requirements. Sensor configuration is made easy through the sbgCenter interface, provided in
the SDK. The Ellipse supports a proprietary protocol for best performance, but also standard protocols such
as NMEA for direct integration into existing applications.
1.1. Ellipse Overview
The following diagram shows the basic organization of an Ellipse-E or N. On the Ellipse-A version, this block
diagram is slightly simplify as there is no GPS, barometer inside.
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Figure 1.1: The Ellipse INS (N model)
Figure 1.2: Ellipse simplified block diagram
Sensors sampling &
Calibration
Coning & Sculling
integrals @ 1 kHz
EKF and output
@ 200 Hz
IMU DATA FUSION
3 Axis
Gyroscopes
3 Axis
Accelerometers
3 Axis
Magnetometers
POWER
CAN
SERIA
GPS
Aiding Equipments
» Dual Antenna GPS, GPS/GNSS, RTK
»
Odometer
BARO

Ellipse AHRS & INS – Hardware Manual E IPSEHM.1.2
1.2. Inertial measurement unit
As an IMU is the main component of an inertial navigation system, the Ellipse IMU has been carefully
designed to take full advantage and performance of MEMS technology.
1.2.1. Accelerometers
The Ellipse IMU embeds a set of 3 MEMS capacitive accelerometers. Coupled with advanced filtering
techniques and sculling integrals, these accelerometers will provide consistent performance, even in
vibrating environment.
A2 A3 Remarks
Full scale ( g )8 16
Scale factor stability (%) 0.1 0.1
Non- inearity (% of FS) 0.2 0.2
One year bias stability (m g )5 10
Velocity Random Walk (µ g /√hz) 100 (X, Y)
150 (Z)
200 (X, Y)
300 (Z)
Allan variance – @ 25°C
In run bias instability (µ g )20 40 Allan variance – @ 25°C
Vibration Rectification Error (m g / g ²) 7 4
Bandwidth (Hz) 250 250 Internal low pass filters attenuation < 3 dB
Sampling rate (kHz) 3 3
Orthogonality (°) < 0.05 < 0.05
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1.2.2. Gyroscopes
The set of 3 high end industrial grade MEMS gyroscopes is sampled at 10 KHz. An efficient FIR filter and
coning integrals computations ensures best performance in vibrating environments.
G2 G3 G4 G5 Remarks
Full scale (°/s) 100 200 450 1000
Scale factor stability (%) 0.05 0.05 0.05 0.05
Non- inearity (% of FS) 0.05 0.05 0.05 0.05
One year bias stability (°/s) 0.2 0.2 0.2 0.4 Total composite bias
In run bias instability (°/hr) 8 8 8 10 Allan variance – @ 25°C
Angular Random Walk (°/√hr) 0.16 0.16 0.18 0.18 Allan variance – @ 25°C
Bandwidth (Hz) 133 133 133 133 Internal Gyro bandwidth
Sampling rate (kHz) 10 10 10 10 Advanced anti-aliasing FIR filter
Orthogonality (°) 0.05 0.05 0.05 0.05
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1.3. Aiding sensors
Many different aiding sensors can be used to aid the Ellipse INS.
1.3.1. Internal Magnetometers
A set of three Anisotropic Magneto-resistive magnetometers is embedded within the Ellipse. This
technology provides a very high sensitivity compared to coil based technologies.
Although part of the Ellipse internal IMU, the magnetometer is in fact considered as an “aiding sensor” and
is not mandatory for proper operation.
Nevertheless, in many applications such AHRS applications, airborne or several marine applications, this
magnetometer is still a reliable and efficient way to observe heading.
Note: Magnetometer use requires a specific in place calibration in order to compensate surrounding
ferromagnetic materials and magnets. Please refer to the Ellipse Hard and Soft Iron Calibration
Manual for more information about this.
Warning: Note that magnetometer sampling design makes it impossible to reject signal
frequencies above 180Hz. User should ensure that high frequency noise is not disturbing
magnetometers at the sensor's location.
Specifications Remarks
Full scale (Gauss) 8
Scale factor stability (%) 0.5
inearity (% of FS) 0.1
Noise (µGauss) 200 Over 1 to 25 Hz band
Bias stability (m Gauss) 0.5
Bandwidth (Hz) 110
Resolution (mGauss) 2
Sampling rate (Hz) 220
Orthogonality (°) 0.1 After user magnetic calibration
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