SBG Ellipse Micro Series User manual

ELLIPSE Micro series
High Performance, Micro-Inertial Sensors
Hardware Manual
intro
Document ELLIPSEMHM.1.1
Re ision 1.1 - Jul 10, 2018
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ELLIPSE2 Micro series – Hardware Manual ELLIPSEMHM.1.1
Re ision history
Re . Date Author Information
1.1 Jul 10, 2018 Alexis Guinamard [ELI2MHM-1] - Fixed Cable assembly reference pro ided page 14
[ELI2MHM-3] - Added support for ELLIPSE Micro M2 hardware
1.0 Apr 10, 2018 Alexis Guinamard First official ersion of this document
0.9 Oct 24, 2017 Alexis Guinamard First draft ersion of this document
© 2007 – 2018, SBG Systems SAS. All rights reser ed. 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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ELLIPSE2 Micro series – Hardware Manual ELLIPSEMHM.1.1
Index
Terminology............................................................................................................................................................ 5
1. Introduction....................................................................................................................................................... 6
1.1. Ellipse Micro O er iew................................................................................................................................ 6
1.2. Inertial measurement unit specifications................................................................................................. 7
1.2.1. Accelerometers......................................................................................................................................................................... 7
1.2.2. Gyroscopes............................................................................................................................................................................... 7
1.3. Aiding sensors........................................................................................................................................... 8
1.3.1. Internal Magnetometers.......................................................................................................................................................... 8
1.3.2. External sensors...................................................................................................................................................................... 9
1.3.2.1. Third party GNSS recei er............................................................................................................................................... 9
1.3.2.2. Odometer....................................................................................................................................................................... 9
1.4. AHRS specifications.................................................................................................................................. 9
1.5. INS specifications..................................................................................................................................... 10
1.5.1. Land applications.................................................................................................................................................................... 10
1.5.2. Marine applications............................................................................................................................................................... 10
1.5.3. Airborne applications............................................................................................................................................................. 10
2. Mechanical and Electrical specifications.......................................................................................................... 11
2.1. Mechanical specifications......................................................................................................................... 11
2.1.1. De ice mechanical alignment................................................................................................................................................. 12
2.1.2. Origin of measurements........................................................................................................................................................ 12
2.1.3. De ice coordinate frame........................................................................................................................................................ 12
2.1.4. De ice labels........................................................................................................................................................................... 12
2.1.5. Ellipse micro mechanical outline........................................................................................................................................... 13
2.1.5.1. Front iew...................................................................................................................................................................... 13
2.1.5.2. Top iew......................................................................................................................................................................... 13
2.1.5.3. Right iew..................................................................................................................................................................... 13
2.2. Electrical specifications........................................................................................................................... 14
2.2.1. Main connector....................................................................................................................................................................... 14
2.2.1.1. Connector specifications............................................................................................................................................... 14
2.2.1.2. Pin out in RS-422 mode................................................................................................................................................ 15
2.2.1.3. Pin out in RS-232 mode................................................................................................................................................ 15
2.2.2. Electrical specifications......................................................................................................................................................... 16
3. Interfaces specifications.................................................................................................................................. 17
3.1. O er iew.................................................................................................................................................... 17
3.1.1. Interfaces a ailability and multiplexing................................................................................................................................. 17
3.2. Serial interfaces....................................................................................................................................... 17
3.2.1. Supported protocols............................................................................................................................................................... 17
3.2.2. Ports functions Mapping...................................................................................................................................................... 18
3.3. CAN 2.0 A/B interface............................................................................................................................. 18
4. Important notices............................................................................................................................................ 19
4.1. Absolute maximum ratings..................................................................................................................... 19
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ELLIPSE2 Micro series – Hardware Manual ELLIPSEMHM.1.1
4.2. Maintenance............................................................................................................................................ 19
4.2.1. Cleaning.................................................................................................................................................................................. 19
4.3. Support................................................................................................................................................... 20
4.4. Warranty, liability and return procedure................................................................................................ 20
5. Appendix A: Ordering codes and Accessories................................................................................................. 21
5.1. Ellipse Micro ordering codes..................................................................................................................... 21
5.2. De elopment kits.................................................................................................................................... 22
5.2.1. DK-ELI-M................................................................................................................................................................................ 22
5.3. Associated Software............................................................................................................................... 22
5.3.1. SW-QINERTIA-LITE (GNSS/INS Post Processing Software)................................................................................................ 22
5.4. Cables...................................................................................................................................................... 23
5.4.1. CA-ELI-M-OW-0.25M............................................................................................................................................................ 23
5.5. GNSS antennas....................................................................................................................................... 24
5.5.1. ANT-TAL-TW-32-2710-00-3000............................................................................................................................................. 24
5.5.1.1. Performance specifications.......................................................................................................................................... 24
5.5.1.2. Mechanical drawing..................................................................................................................................................... 24
6. Appendix B: E aluation board documentation.............................................................................................. 25
6.1. Board o er iew......................................................................................................................................... 25
6.2. Board configuration Switches................................................................................................................ 25
6.3. Flashing a firmware using the Ellipse Micro de elopment board.........................................................26
6.4. Schematics.............................................................................................................................................. 26
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ELLIPSE2 Micro series – Hardware Manual ELLIPSEMHM.1.1
Terminology
ADC: Analog to Digital Con erter
AHRS: Attitude and Heading Reference System
CAN (Bus): Controller Area Network
DHCP: Dynamic Host Configuration Protocol
DVL: Doppler Velocity Log
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 Na igation Satellite System
GPS: Global Positioning System
IIR: Infinite Impulse Response (filter)
IMU: Inertial Measurement Unit
INS: Inertial Na igation System
IP: Internet Protocol
LBL: Long 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 Merchandise Authorization
RMS: Root Mean Square
RTCM: Radio Technical Commission for Maritime Ser ices (Protocol)
RTK: Real Time Kinematics
SI: International System of Units
TBD: To Be Defined
TCP: Transmission Control Protocol
UDP: User Datagram Protocol
UTC: Coordinated Uni ersal Time
USBL: Ultra Short Base Line
VRE: Vibration Rectification Error
WGS84: World Geodetic System 1984
WMM: World Magnetic Model
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ELLIPSE2 Micro series – Hardware Manual ELLIPSEMHM.1.1
1. Introduction
The Ellipse2 Micro series is a line of sub-miniature, high-
performance MEMS based Inertial Systems which achie e
exceptional orientation and na igation performance in a tiny and
affordable package. It includes an Inertial Measurement Unit (IMU)
and runs an on-board enhanced Extended Kalman Filter (EKF). The
Ellipse line is di ided in a comprehensi e set of sensors:
●The Ellipse2 Micro IMU is an Inertial Measurement Unit that
can be used for high performance motion monitoring, thanks
to its factory calibrated gyroscopes, accelerometers and
magnetometer outputs.
●The Ellipse2 Micro AHRS ersion is an attitude and Heading Reference System (AHRS), pro iding
accurate orientation in dynamic conditions.
●The Ellipse2 Micro INS is an Inertial Na igation System (INS), pro iding both orientation and
na igation data. An external GNSS data can be connected to the Ellipse2 Micro, and other aiding
equipment such as odometer can be used to pro ide accurate na igation data under harsh conditions,
but also to impro e orientation accuracy:
To achie e the best performance in e ery project, specific error models ha e been implemented to meet
applications requirements. Sensor configuration is made easy through the sbgCenter interface, pro ided 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.
The Ellipse2 Micro series is fully compatible with the larger size Ellipse modules as it shares the same
communication protocol.
1.1. Ellipse Micro O er iew
The following diagram shows the basic organization of an Ellipse Micro module.
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Figure 1.1: The Ellipse Micro
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
SERIAL
Aiding Equipments
» Dual Antenna GPS/GNSS, RTK
»
Odometer

ELLIPSE2 Micro series – Hardware Manual ELLIPSEMHM.1.1
1.2. Inertial measurement unit specifications
As an IMU is the main component of an inertial na igation system, the new Ellipse IMU has been carefully
designed to take full ad antage and performance of MEMS technology.
1.2.1. Accelerometers
The Ellipse Micro IMU embeds 3 high performance, industrial grade MEMS accelerometers. Coupled with a
cutting edge calibration, ad anced filtering techniques and sculling integrals, these accelerometers will
pro ide excellent performance, e en in highly ibrating en ironment.
The A2 ersion is dedicated to marine applications requiring high performance hea e measurements, while
the A3 ersion is suitable to all other applications.
A2 A3 A4 Remarks
Full scale ( g )8 16 40
Scale factor stability (ppm) 1000 1000 1000 After one year accelerated aiging
Non-Linearity (ppm of FS) 6300 1500 1500 Best Fit Straight Line
One year bias stability (m g )2 5 5 After one year accelerated aiging
Velocity Random Walk (µ g /√hz) 12 57 57
In run bias instability (µ g )3 14 14 Allan ariance – @ 25°C
Vibration Rectification Error (µ g / g ²) 200 50 50 Tested up to 3g RMS for A2 and 10g RMS
for A3/A4
Bandwidth (Hz) 390 390 390 Internal low pass filters attenuation < 3 dB
Sampling rate (kHz) 4 4 4 Ad anced anti-aliasing FIR filter
Orthogonality (°) 0.05 0.05 0.05
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 ibrating en ironments.
G4 range is suitable to most applications, while the G5 is adapted for high dynamic applications.
G4 G5 Remarks
Full scale (°/s) 450 1000
Scale factor stability (ppm) 500 500 After one year accelerated aiging
Non-Linearity (% of FS) 50 50
One year bias stability (°/s) 0.2 0.4 After one year accelerated aiging
Angular Random Walk (°/√hr) 0.15 0.18 Allan ariance – @ 25°C
In run bias instability (°/hr) 7 8 Allan ariance – @ 25°C
Vibration Rectification Error (°/h/g²) < 1 < 1 Tested up to 10g RMS
Bandwidth (Hz) 133 133 Internal Gyro bandwidth
Sampling rate (kHz) 10 10 Ad anced anti-aliasing FIR filter
Orthogonality (°) 0.05 0.05
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ELLIPSE2 Micro series – Hardware Manual ELLIPSEMHM.1.1
1.3. Aiding sensors
Many different aiding sensors can be used to aid the Ellipse Micro.
1.3.1. Internal Magnetometers
A set of three Anisotropic Magneto-resisti e magnetometers is embedded within the Ellipse. This
technology pro ides a ery high sensiti ity 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.
Ne ertheless, in many applications such AHRS applications, airborne or se eral marine applications, this
magnetometer is still a reliable and efficient way to obser e 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
abo e 75Hz. User should ensure that high frequency noise is not disturbing magnetometers at the
sensor's location.
Specifications Remarks
Full scale (Gauss) 50
Scale factor stability (%) 0,5
Noise (mGauss) 3 O er 1 to 25 Hz band
Bias stability (m Gauss) 1
Bandwidth (Hz) 22 -3dB attenuation
Resolution (mGauss) 1.5
Sampling rate (Hz) 100
Orthogonality (°) 0.1 After user magnetic calibration
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ELLIPSE2 Micro series – Hardware Manual ELLIPSEMHM.1.1
1.3.2. External sensors
1.3.2.1. Third party GNSS recei er
The Ellipse-E model does not include a GNSS recei er, but can be connected to an external GNSS module. All
GNSS recei ers will pro ide elocity and position aiding.
Dual antenna recei ers can also pro ide a True Heading aiding. RTK GPS recei ers can be used to impro e
positioning accuracy.
1.3.2.2. Odometer
In addition to the GNSS aiding, the Ellipse micro ‘E’ ersion includes two sync inputs that can be used as
odometer input. This can greatly impro e performance in challenging en ironments such as urban canyons.
The odometer pro ides a reliable elocity information e en during GPS outages. This increases significantly
the dead reckoning accuracy.
Warning: In a typical INS setup, one sync IN will be dedicated to PPS input and the second can be
used as odometer input. It means that the Ellipse Micro can only handle uni-directional odometers.
If you need direction detection please consider using the full featured Ellipse sensor instead of
Ellipse Micro.
Note: Odometer integration is made really simple as the Kalman filter will finely adjust odometer's
gain and will correct residual errors in the odometer alignment and le er arm.
1.4. AHRS specifications
All specifications are rated to 1 , o er -40°C to +85°C (-40 to σ185°F) unless otherwise stated.
These specifications ha e been measured based on typical mission scenarios with simulated GPS outages
and compared to post processed RTK data of a high end FOG based INS.
Performance Remarks
Measurement range 360° in all axes, no mounting limitation
Roll / Pitch accuracy < 0.1° Low dynamic conditions – No long term accelerations
Yaw Accuracy 0.8° Clean magnetic en ironment – Magnetic calibration performed
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ELLIPSE2 Micro series – Hardware Manual ELLIPSEMHM.1.1
1.5. INS specifications
For each application, the accuracy parameters are defined in different positioning modes, explained below:
●SP refers to Single Point mode and is the default L1 GPS / GLONASS fix quality
●RTK stands for Real Time Kinematics with a typical 1 cm accuracy position
●Odometer Aiding is specified when an odometer pro ides elocity (automoti e applications)
1.5.1. Land applications
All specifications are alid with DMI (odometer) aiding for typical land applications trajectories.
Outage
Duration Positioning Mode Position Accuracy Velocity Accuracy Attitude Accuracy (°)
Horizontal Vertical Horizontal Vertical Roll / Pitch Heading
No Outage SP 2 m 2.5 m 0.1 m/s 0.1 m/s 0.1 ° 0.3 °
RTK 0.02 m 0.04 m 0.05 m/s 0.05 m/s 0.1 ° 0.3 °
10 s SP 2.5 m 3 m 0.2 m/s 0.2 m/s 0.1 ° 0,3 °
RTK 0.8 m 0.8 m 0.15 m/s 0.15 m/s 0.1 ° 0.3 °
60 s SP 9 m 6 m 0.1 m/s 0.1 m/s 0.1 ° 0.5 °
RTK 7 m 4 m 0.1 m/s 0.1 m/s 0.1 ° 0.5 °
1.5.2. Marine applications
Outage
Duration Positioning Mode Position Accuracy Velocity Accuracy Attitude Accuracy (°)
Horizontal Vertical Horizontal Vertical Roll / Pitch Heading
No outage
SP 2 m 2.5 m 0.1 m/s 0.1 m/s 0.1 ° 0.8 °
RTK / Dual
antenna GPS 0.02 m 0.04 m 0.05 m/s 0.05 m/s 0.2 ° 0.2 °
10 s
SP 3 m 3.5 m 0.2 m/s 0.2 m/s 0.3 ° 0.8 °
RTK / Dual
antenna GPS 1 m 1 m 0.15 m/s 0.15 m/s 0.3 ° 0.3 °
Note: In case of standalone dual antenna GNSS system use, heading accuracy parameters listed in
“RTK / Dual antenna GPS” lines may apply.
1.5.3. Airborne applications
Positioning Mode Position Accuracy Velocity Accuracy Attitude Accuracy (°)
Horizontal Vertical Horizontal Vertical Roll / Pitch Heading
SP 2 m 2.5 m 0.1 m/s 0.1 m/s 0.1 ° 0.5 °
RTK 0.02 m 0.04 m 0.05 m/s 0.05 m/s 0.1 ° 0.4 °
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