Xsens MTi 10 Series User manual

Xsens Technologies B.V.
Xsens North America, Inc.
Pantheon 6a
P.O. Box 559
7500 AN Enschede
The Netherlands
phone [phone]
fax [phone]
e-mail [email protected]m
internet www.xsens.com
10557 Jefferson Blvd,
Suite C
CA-90232 Culver City
USA
phone [phone]
fax [phone]
e-mail [email protected]m
internet www.xsens.com
Document MT0605P, Revision E, 17 January 2014
MTi 10-series and MTi 100-series
MTi User Manual

Document MT0605P.E
© Xsens Technologies B.V.
MTi User Manual
ii
Revisions
Revision
Date
By
Changes
A
26 Sep 2012
MHA
Initial release
B
18 Dec 2012
MHA
Included MTi-G-700
C
07 May 2013
MHA
D
28 October 2013
MHA
Added NMEA, StartSampling,
vibration mounts
E
17 January 2014
MHA
Added product code, 3V3 and remark
on termination resistor
© 2005-2014, Xsens Technologies B.V. All rights reserved. Information in this document is subject to
change without notice. Xsens, MVN, MotionGrid, MTi, MTi-G, MTx, MTw, Awinda and KiC are
registered trademarks or trademarks of Xsens Technologies B.V. and/or its parent, subsidiaries and/or
affiliates in The Netherlands, the USA and/or other countries. All other trademarks are the property of
their respective owners.

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Table of Contents
1REFERENCES ..................................................................................................................................... 2
2INTRODUCTION ................................................................................................................................ 3
2.1 MTI 10-SERIES ................................................................................................................................. 3
2.1.1 MTi-30 AHRS........................................................................................................................ 3
2.1.2 MTi-20 VRU ......................................................................................................................... 3
2.1.3 MTi-10 IMU ......................................................................................................................... 3
2.2 MTI 100-SERIES ............................................................................................................................... 4
2.2.1 MTi-G-700 GPS/INS .............................................................................................................. 4
2.2.2 MTi-300 AHRS ...................................................................................................................... 4
2.2.3 MTi-200 VRU........................................................................................................................ 4
2.2.4 MTi-100 IMU........................................................................................................................ 4
2.2.5 Identifying device functionality using the unique Device Identifier ............................................ 5
2.2.6 Product code ........................................................................................................................ 5
2.3 EVOLUTION OF MTI PRODUCTS.............................................................................................................. 6
2.4 OVERVIEW MTI DEVELOPMENT KIT ........................................................................................................ 7
2.4.1 Contents .............................................................................................................................. 7
2.5 INSTALLATION................................................................................................................................... 8
2.5.1 Transient accelerations ......................................................................................................... 8
2.5.2 Vibrations ............................................................................................................................ 8
2.5.3 Magnetic materials and magnets .......................................................................................... 9
2.6 TYPICAL USER SCENARIOS ..................................................................................................................10
2.6.1 MT Software Suite .............................................................................................................. 10
2.6.2 Getting Started with the MT Manager..................................................................................11
2.6.3 Using the Software Development Kit (SDK) ...........................................................................12
2.6.4 Direct low-level communication with MTi .............................................................................14
2.6.5 Migration from MT SDK 3.3 (CMT) ....................................................................................... 14
2.6.6 Terms of use MT Software Suite...........................................................................................15
3MTI SYSTEM OVERVIEW .................................................................................................................. 16
3.1 CALIBRATION .................................................................................................................................16
3.2 XSENS KALMAN FILTER (XKF3I)FOR MTI 10-SERIES ..................................................................................16
3.2.1 Using the acceleration of gravity to stabilize inclination (roll/pitch) ........................................16
3.2.2 Using the Earth magnetic field to stabilize yaw .....................................................................17
3.2.3 Initialization.......................................................................................................................17
3.2.4 XKF3i filter profiles.............................................................................................................. 17
3.3 XSENS SENSOR FUSION ALGORITHM FOR MTI 100-SERIES ............................................................................19
3.3.1 MTi 100-series filter ............................................................................................................ 19
3.3.2 Transient accelerations .......................................................................................................19
3.3.3 Magnetic distortions........................................................................................................... 19
3.3.4 Loss of GPS ........................................................................................................................ 19
3.3.5 MTi 100-series filter profiles ................................................................................................19
3.3.6 MTi-G-700 filter profiles ......................................................................................................20
4OUTPUT SPECIFICATION .................................................................................................................. 22
4.1 OVERVIEW OF DATA OUTPUTS .............................................................................................................23
4.1.1 MTData2 output in XBus protocol ........................................................................................23
4.1.2 NMEA protocol...................................................................................................................24

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4.2 COORDINATE SYSTEMS ......................................................................................................................25
4.2.1 Calibrated inertial data and magnetic field data ................................................................... 25
4.2.2 Delta_angle and delta_velocity............................................................................................25
4.2.3 Orientation data................................................................................................................. 26
4.2.4 Velocity data......................................................................................................................27
4.2.5 Position data...................................................................................................................... 27
4.3 ORIENTATION PERFORMANCE SPECIFICATION ...........................................................................................30
4.4 POSITION AND VELOCITY PERFORMANCE SPECIFICATION (MTI-G-700) ............................................................ 31
4.5 ORIENTATION OUTPUT MODES............................................................................................................. 31
4.5.1 Quaternion orientation output mode ...................................................................................32
4.5.2 Euler angles orientation output mode .................................................................................. 33
4.5.3 Rotation Matrix orientation output mode.............................................................................33
4.6 SENSOR DATA PERFORMANCE SPECIFICATION ...........................................................................................35
4.6.1 Gyroscopes ........................................................................................................................ 35
4.6.2 Accelerometers and magnetometer .....................................................................................36
4.6.3 Y zBarometer .....................................................................................................................36
4.6.4 GPS receiver.......................................................................................................................37
4.7 BUILT-IN SELF-TEST ..........................................................................................................................38
4.8 TEST AND CALIBRATION CERTIFICATE .....................................................................................................39
4.9 SENSORS DATA OUTPUTS....................................................................................................................40
4.9.1 Physical sensor model .........................................................................................................40
4.9.2 Calibrated delta_q and delta_v outputs................................................................................41
4.9.3 Calibrated inertial and magnetic data outputs ...................................................................... 41
4.9.4 Free acceleration ................................................................................................................ 41
4.9.5 Uncalibrated raw output mode............................................................................................42
4.10 LEGACY OUTPUT MESSAGES ................................................................................................................ 43
4.11 RESET OF OUTPUT OR REFERENCE CO-ORDINATE SYSTEMS ............................................................................ 44
4.12 TIMESTAMP AND PACKET COUNTER OUTPUT ............................................................................................ 47
4.12.1 Packet counter ................................................................................................................... 47
4.12.2 Time UTC ........................................................................................................................... 47
4.12.3 Time stamp (Sample Time Fine) ...........................................................................................47
4.12.4 Setting UTC time on non-GPS MTi’s......................................................................................47
4.13 STATUS BYTE ..................................................................................................................................48
5BASIC COMMUNICATION ................................................................................................................ 50
5.1 INTRODUCTION ...............................................................................................................................50
5.2 STATES.........................................................................................................................................50
5.3 MESSAGES ....................................................................................................................................51
5.3.1 Message structure .............................................................................................................. 51
5.3.2 Message usage ..................................................................................................................52
5.3.3 Common messages.............................................................................................................53
5.4 COMMUNICATION TIMING .................................................................................................................54
5.5 TRIGGERING AND SYNCHRONIZATION .....................................................................................................57
5.5.1 External device triggers MTi (Send Latest) ............................................................................ 57
5.5.2 Marker in MT data (Trigger Indication) ................................................................................ 57
5.5.3 MTi triggers external devices (Interval Transition Measurement) ...........................................58
5.5.4 Clock synchronization (Clock Bias Estimation) .......................................................................59
5.5.4.1 Clock Bias Estimation from GPS ...........................................................................................59
5.5.5 StartSampling .................................................................................................................... 59
5.5.6 Combining synchronization functions ...................................................................................60

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5.6 INTERNAL CLOCK ACCURACY ................................................................................................................ 61
5.6.1 Clock of MTi’s without GPS receiver ..................................................................................... 61
5.6.2 Clock of MTi-G-700 GPS/INS ................................................................................................61
5.7 DEFAULT SERIAL CONNECTION SETTINGS ................................................................................................61
5.7.1 General definitions for binary data.......................................................................................62
5.7.2 Serial or USB communication...............................................................................................62
6PHYSICAL SPECIFICATIONS............................................................................................................... 63
6.1 PHYSICAL PROPERTIES OVERVIEW.......................................................................................................... 63
6.2 POWER SUPPLY ............................................................................................................................... 63
6.2.1 Alternative 3V3 power supply .............................................................................................. 64
6.3 MECHANICAL AND ELECTRICAL INTERFACE SPECIFICATIONS ...........................................................................65
6.3.1 Encased MTi connectors overview........................................................................................ 65
6.3.2 OEM connections overview ................................................................................................. 67
6.3.3 Additional interface specifications .......................................................................................69
6.3.4 Using the MTi MkIV with an external USB converter .............................................................. 70
6.4 HOUSING MECHANICAL SPECIFICATIONS.................................................................................................. 71
6.4.1 Environmental protection of the housing .............................................................................. 71
6.4.2 Dimensions MTi.................................................................................................................. 71
6.4.3 Mounting the MTi-OEM ......................................................................................................71
6.4.4 MTi 10-series technical drawing .......................................................................................... 72
6.4.5 MTi 100-200-300 technical drawing ..................................................................................... 73
6.4.6 MTi-G-700 technical drawing ..............................................................................................74
6.4.7 MTi-OEM technical drawing ................................................................................................75
7IMPORTANT NOTICES...................................................................................................................... 76
7.1 SAFETY INSTRUCTIONS.......................................................................................................................76
7.2 ABSOLUTE MAXIMUM RATINGS ............................................................................................................ 76
7.3 MAINTENANCE ...............................................................................................................................76
7.4 CE DECLARATION OF CONFORMITY FOR THE MT DEVICES ............................................................................77
7.5 FCC DECLARATION OF CONFORMITY FOR THE MT DEVICES ..........................................................................78
7.6 WARRANTY AND LIABILITY .................................................................................................................. 79
7.7 CUSTOMER SUPPORT........................................................................................................................79

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1 References
Reference
id
Document description
[LLCP]
“MT Low-Level Communication Protocol Documentation.pdf”, document ID
MT0101P
[MTM]
“MT Manager User Manual.pdf”, document ID MT0216P
[XDA_DOC]
XDA doxygen HTML documentation. Found in Xsens folder structure
[MTI_TD]
“MTi Technical Datasheet.pdf”, document ID MT0503P

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2 Introduction
The MTi product portfolio from Xsens currently has 7 family members ranging in functionality from
inertial measurement units (IMU’s) to a fully integrated GPS/INS solution. All products contain a 3D
inertial sensor assembly (ISA: gyroscopes and accelerometers) and 3D magnetometers, with
optionally a barometer and GNSS receiver.
The MTi product range is divided in two series, the MTi 10-series and the MTi 100-series. The MTi 10-
series is Xsens’ entry level model with robust accuracy and a limited range of IO options. The 100-
series is a revolutionary new class of MEMS IMU’s, orientation and position sensor modules offering
unprecedented accuracies and a wide array of IO interfaces.
All MTi’s have a powerful multi-processor core design, capable of processing roll, pitch and yaw with
extremely low latencies, as well as outputting calibrated 3D linear acceleration, rate of turn (gyro),
(earth) magnetic field and atmospheric pressure (100-series only) data. The MTi-G-700 GPS/INS also
offers 3D position and 3D velocity. Over 50 various output formats can be provided directly from the
MTi interface. The various outputs per product can be found in section 4.1.
This documentation describes the use, basic communication interfaces and specifications of all the 7
MTi’s. Where they differ is clearly indicated. All products are designed to be interchangeable from a
mechanical and software interface point of view.
2.1 MTi 10-series
The MTi 10-series is the basic product range of the MTi
product portfolio, offering inertial data and orientation data at
an affordable price. The MTi 10-series consists of 3 products
that have various integration levels.
The MTi-10 series can easily be recognized by the silver base
plate. There are no visual differences between the MTi-10
IMU, MTi-20 VRU and MTi-30 AHRS, other than the label.
2.1.1 MTi-30 AHRS
The MTi-30 AHRS is a full gyro-enhanced Attitude and Heading Reference System (AHRS). It outputs
drift-free roll, pitch and true/magnetic North referenced yaw, plus sensors data: 3D acceleration, 3D
rate of turn and 3D earth-magnetic field data. All products of the MTi 10-series are also capable of
outputting data generated by the Strapdown integration algorithm (orientation and velocity increments
∆q and ∆v).
2.1.2 MTi-20 VRU
The MTi-20 VRU is a 3D vertical reference unit (VRU), which means that it outputs the same data as
the MTi-30, except for the referenced yaw. They yaw is unreferenced, though still superior to just
gyroscope integration.
2.1.3 MTi-10 IMU
The MTi-10 IMU is a 3D inertial measurement unit (IMU) that outputs 3D acceleration, 3D rate of turn
and 3D earth-magnetic field data, so it doesn’t process data to orientation. The MTi-10-IMU is also
capable of outputting data generated by the Strapdown integration algorithm (orientation and velocity
increments ∆q and ∆v).

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2.2 MTi 100-series
The MTi-100 series is the high-performance product
range of the MTi product portfolio, with accuracies
overpowering conventional MEMS AHRS’s, because
of the use of superior gyroscopes and a new
optimization filter, going beyond (Extended) Kalman
Filter implementations. In addition, the factory
calibration is more elaborate to make use of these
higher class gyroscopes.
The MTi 100-series can be recognized by the dark-
grey base plate and the holes on one side of the
casing. These holes are used for the adaptation of
the inside air pressure to atmospheric pressure,
required for a proper working of the barometer. Note that the electronics inside is protected with a vent
that keeps the casing IP67 rated. There are no visual differences between the MTi-100 IMU, MTi-200
VRU and MTi-300 AHRS, other than the label. The MTi-G-700 has an extra SMA connector to allow a
GPS antenna to be attached.
2.2.1 MTi-G-700 GPS/INS
The flagship of the MTi product portfolio is the MTi-G-700 GPS/INS, a fully integrated solution that
includes an onboard GPS receiver. The MTi-G-700-GPS/INS is thus capable of not only outputting
GPS-enhanced 3D orientation, it can also output AHRS-augmented 3D position and velocity, so that
velocity and position accuracy significantly improve with respect to the accuracy of the GPS receiver
alone. Furthermore, it provides 3D sensors data, such as acceleration, rate of turn, magnetic field, the
navigation solution of the GPS receiver and static pressure. Data generated from the strapdown
integration algorithm (orientation and velocity increments ∆q and ∆v) are available, as all other
processed data, at 400 Hz.
2.2.2 MTi-300 AHRS
The MTi-300 AHRS is a full gyro-enhanced Attitude and Heading Reference System (AHRS). It
outputs drift-free roll, pitch and true/magnetic North referenced yaw. It also outputs sensors data and
data generated from the Strapdown integration algorithm as well as described in section 2.2.1.
2.2.3 MTi-200 VRU
The MTi-200 VRU is a 3D vertical reference unit (VRU) and this unit too runs the Xsens sensor fusion
algorithm from the MTi-G-700 and MTi-300. The difference between the data of the MTi-300 and MTi-
200 is that yaw is unreferenced, though the yaw is still much better than just integrating rate of turn.
2.2.4 MTi-100 IMU
The MTi-100 IMU is a 3D inertial measurement unit (IMU) that outputs 3D acceleration, 3D rate of turn
and 3D earth-magnetic field data. The MTi-10-IMU is also capable of outputting data generated by the
Strapdown integration algorithm (orientation and velocity increments ∆q and ∆v).

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2.2.5 Identifying device functionality using the unique Device Identifier
Each Xsens product is marked with a unique serial device identifier referred to as the DeviceID. The
DeviceID is categorized per MTi product configuration in order to make it possible to recognize the MTi
(and thus its functionality and interface) by reviewing the DeviceID. The second digit of the DeviceID
denotes the functionality (e.g. ‘1’ for MTi-10 and MTi-100), the third digit denotes the product series (6
for MTi 10-series, 7 for MTi 100-series) and the fourth digit denotes the interface (e.g. ‘0’ for
RS232+USB). The last four digits are unique for each device; these four digits have a hexadecimal
format.
Below is a list of the products and interfaced with their corresponding products.
Product
RS232+USB
RS422
RS485+USB
MTi-10 IMU
0160xxxx
0161xxxx
0163xxxx
MTi-20 VRU
0260xxxx
0261xxxx
0263xxxx
MTi-30 AHRS
0360xxxx
0361xxxx
0363xxxx
MTi-100 IMU
0170xxxx
0171xxxx
0173xxxx
MTi-200 VRU
0270xxxx
0271xxxx
0273xxxx
MTi-300 AHRS
0370xxxx
0371xxxx
0373xxxx
MTi-G-700 GPS/INS
0770xxxx
0771xxxx
0773xxxx
2.2.6 Product code
The product code of the MTi MkIV consists of a number of characters that represent the product type,
full ranges of the inertial sensors, the interface and the casing option. The table below shows the
product code build-up.
Format
MTi-
####
-
*
A*
G*
Example
MTi-
G-700
-
2
A5
G4
-OEM
10
IMU
2
RS232
A5
5g
G4
450 º/s
Blank
Alu casing
20
VRU
4
RS485
A8
15g
G0
1000 º/s
-OEM
No casing
30
AHRS
6
RS422
100
IMU
200
VRU
300
AHRS
G-700
GPS/INS

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2.3 Evolution of MTi products
The MTi 10-series and MTi 100-series are Xsens 4th generation products, building on knowledge and
products from over a decade. They may be designated as MkIV MTi’s. In source code or software, this
can be Mk4.
In this manual, the term legacy MTi, MTx or MTi-G may be used. In these cases, it is referred to the
previous generation products, which set the standard in MEMS Motion Tracking technology.
Also included in the Motion Tracker range is the wireless MTw, which has a close resemblance to the
MTi 10-series and MTi 100-series in terms of system architecture and interfacing.
The MTi 10-series and MTi 100-series are described in detail in section 2.1 and 2.2, for completeness
they are listed below as well:
Product name
Description
Availability
Product photo
Legacy MTi
The standard setting MTi is a full 3D
AHRS, comparable in function to the
MTi-30 and MTi-300. It has a plastic
casing and aluminum bottom plate.
Product codes are in the form of MTi-
28A53G35
Introduced:
2005
Available: at
least till Dec
2013
Legacy MTi-OEM
The OEM board of the legacy MTi.
The board is green (contrary to
orange MTi-10s and MTi-100s OEM
board)
Introduced:
2006
Available: at
least till Dec
2013
Legacy MTx
Designed as a Motion Tracker for
human movements, this low-weight
Motion Tracker has a fully plastic
casing. Product codes are in the form
of MTx-28A53G25
Introduced:
2005
Available: at
least till Dec
2013
Legacy MTi-G
The GPS-aided MTi-G offers reliable
orientation during accelerations. The
successor of the MTi-G is the MTi-G-
700. The casing is as the legacy
MTi’s casing. Product codes are in
the form of MTi-G-28A53G35.
Introduced:
2007
Available: at
least till Dec
2013
MTw
The wireless MTw is available as
single Motion Tracker or in a time-
synchronized network together with
the Awinda station. Product codes are
in the form of MTw-38A70G20.
Introduced:
2010
MTi 10-series,
MTi 100-series
(including MTi-G-
700) and OEM
The latest 4th generation addition to
the Motion Trackers of Xsens (MkIV).
See section 2.1 and 2.2 for more
information. The OEM board is
orange. This manual focuses on
these products. Product codes are in
the form of e.g. MTi-30-2A5G4
Introduced:
2012