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MTi User Manual

1. 59 554 1 Clock Bias Estimation rom GPS isses exu isa set 59 DU SOOO ERTRMTRS 59 5 5 6 Combining synchronization functions 60 Document MT0605P E Xsens Technologies B V IV MTi User Manual 5 6 INTERNALCEOCK ACCURACY ice Sean abe ba m aa adi sau d Ea a cda e rc wa saa s 61 5 6 1 Clock of MTi s without GPS receiver 61 5 6 2 CN COLI 61 5 7 DEFAULT SERIAL CONNECTION SETTINGS cceccccececececsucecuuaueuseeueuuaueusueuuavaueusueauaueueueueavausususavaveueeeauavausess 61 5 71 Genergldelinitions Tor binary DOUG usse eee EP Eae EX Ha EN Ee ken EUER Asse ase Tu eR pas a P DUE 62 5 7 2 Serial or USB COMMUNICATION 62 6 PRY SICAL SPECIFICATIONS Pau RR unis aaa 63 6 1 PHYSICAL PROPERTIES OVERVIEW cccceccucececueueececuueueueucuuauaueeeueauauausueuuauaueueueauaueusueusavaueusueuuaueueeeeeavaneess 63 Mire i20 AT 63 6 2 1 X Alternative 3V3 power 64 6 3 MECHANICAL AND ELECTRICAL INTERFACE SPECIFICATIONS ccececeecececececeucecuceveuee
2. LINT communication Windows _ 7 Linux x88 Embedded MT Manager xsensdeviceapi dll xsensdeviceapi so Source code XBus low level protocol GUI Windows XP 7 DLL with full shared object with Logging and functionality full functionality replaying Documented in documented in Exporting doxygen HTML doxygen HTML Limited functionality Communication Data message interpretation fully documented protocol PDF open source On the left three programs with GUIs are shown Firmware Updater Magnetic Field Mapper and MT Manager These programs offer the possibility to configure the MTi in a very easy way The MT Manager also can be used to communicate with the MTi The MT SDK contains all the developer code such as a DLL a shared object for x86 computers and basic functionality in C source code for embedded systems Of course it is possible to use lower level communication options down to the XBus low level protocol the most functionality however can be found in the DLL and shared object The XBus low level protocol is described in high detail in the Low Level Communication Protocol LLCP The hardware driver of the USB interface for Linux can be found on http github com xsens xsens mt The driver is also included in Linux kernel 3 9 and higher Document MT0605P E Xsens Technologies B V 10 MTi User Manual 2 6 2 Getting Starte
3. x The hex value of the Type bits y The hex value of the Format bits float fixed point coordinate system See the LLCP for more information 4 1 2 NMEA protocol LatLon 504y XDI AngularVelocityGroup 80xy 2000 Hz XDI RateOfTurn 802y DeltaQ 803y XDI GpsGroup 88x0 4 Hz XDI GpsDop 8830 XDI GpsSol 8840 XDI GpsTimeUtc 8880 GpsSvInfo 88A0 XDI_RawSensorGroup A0x0 2000 Hz XDI RawAccGyrMagTemp A010 XDI RawGyroTemp A020 XDI MagneticGroup COxy 100 Hz XDI MagneticField 02 XDI VelocityGroup DOxy 400 Hz XDI VelocityXYZ DO1y XDI StatusGroup 2000 Hz XDI StatusByte E010 XDI StatusWord E020 XDI Rssi E040 The MTi also supports a variety of strings in NMEA protocol Below is a list of the various strings that can be outputted by the MTi Bit String Type Bit 0 HCHDM Bit 1 HCHDG Bit 2 TSS2 Bit 3 Bit 4 PRDID Bit 5 EM1000 Bit 6 PSONCMS Bit 7 HCMTW Bit 8 Bit 9 Bit 10 15 Reserved Description Magnetic Heading Heading with HeadingOffset Heading Heave 0 Status Roll Pitch Heading Status flag F Pitch Roll Pitch Roll Heading Roll Pitch Heave 0 Heading Quaternion Acceleration Rate of Turn Magnetic Field Temp Temperature True Heading Rate of Turn Reserved for future string types Document MTO605P E Xsens Technologies B V 24 MTi User Manual 4 2 Coordinate systems Data from the MTi is rep
4. User Manual 10 series and 100 series Document MTO605P Revision E 17 January 2014 Xsens Technologies B V Xsens North America Inc Pantheon 6a phone 31 0 88 973 67 00 10557 Jefferson Blvd phone 310 481 1800 P O Box 559 fax 31 0 88 973 67 01 Suite C fax 310 416 9044 7500 AN Enschede e mail info xsens com CA 90232 Culver City e mail _ info xsens com The Netherlands internet WWwW Xsens com USA internet www xsens com 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 Document MT0605P E Xsens Technologies B V i MTi User Manual Table of Contents 1 REFERENCES vaa Rar EMMEUFKUISRS EN AM PER EUREN DN FANNIE SES EE RM KMM DE 2 2 INTRODUCTIO
5. 1 Hz Note that these SCR values of the gyroscopes and accelerometers are not calibrated for offset gain misalignment and temperature Also coning and sculling compensation is not applied It is possible to post process SCR data with MT Manager and this output is very suitable if you need to perform your own calibration Note that this output cannot be combined with any other output Document MT0605P E Xsens Technologies B V 42 MTi User Manual 4 10 Legacy output messages The MTi 10 series and MTi 100 series are Xsens 4 generation MTi MkIV The 2 and 39 generation products have been released in 2005 and 2008 The 4 generation can be distinguished by their aluminium casing or orange PCB if you are using an OEM A photo of the 4 generation MTi can be found on the cover of this manual The MTi 10 series and MTi 100 series use the same XBus communication protocol as legacy MTi s MTx s and MTi G s see photo on the right However because of increased functionality and a different signal processing pipeline the MTi 10 series and MTi 100 series are not drop in replaceable in all cases It is possible to configure the MTi s in such a way that they are drop in replaceable in some programs that are based on legacy classes and source Figure 9 Legacy MTi x product code Note that it is only possible to use the MTi in legacy range mode when data is processed onboard the MTi It is not possible to process ra
6. 450 450 Bias repeatability 1 yr deg s 0 2 0 5 0 2 0 5 In run bias stability deg h 18 10 Bandwidth 3dB Hz 415 N A 450 N A Noise density deg s VHz 0 03 0 05 0 01 0 015 g sensitivity calibrated deg s g 0 006 0 02 0 003 0 015 Non orthogonality deg 0 05 0 05 Non linearity FS 0 03 0 1 0 01 A D resolution bits 16 N A 16 N A Document MIO605P E Xsens Technologies B V 35 MTi User Manual 4 6 2 Accelerometers and magnetometer The MTi 10 series and MTi 100 series use the same accelerometers and magnetometer The output of the magnetometer is in arbitrary units a u one a u is the magnetic field strength during calibration at Xsens calibration lab This is approximately 40 uT An accelerometer range of 15g is available as well Accelerometers magnetometer all products MTi 10 MTi 20 MTi 30 MTi 100 MTi 200 MTi 300 MTi G 700 Accelerometers magnetometers specification Acceleration Standard full range Bias repeatability 1 yr In run bias stability Bandwidth 3dB Noise density Non orthogonality Non linearity A D resolution Magnetic field Full range Noise density Non linearity A D resolution 4 6 3 Barometer m s2 m s2 ug Hz ug VHZ deg 96 FS bits uT uGauss VHz FS bits MTi 10 series and MTi 100 series Typical 50 0 03 40 375 80 0 05 0 03 16 200 0 1 12 Max 0 05 N A 150 0 05 0 5 N A 80
7. MIN 2 5 3x SECTION A A SECTION B B SECTION C C 0 5 0 025 6X 3 3 0 1 3x MIN 2 5 4X 3 3 0 1 3X SECTION B B SECTION A A 3 5 0 05 2x 0 2 0 03 3x CRITICAL DIMENSIONS x ALL FACES TEXTURED VD13400 12 M NO SHARP EDGES ALLOWED DETAIL C SCALE 5 1 ALUMINIUM 8060 oe mm CAD drawings STEP are available at request via sales xsens com Document MT0605P E Xsens Technologies B V 72 MTi User Manual 6 4 5 100 200 300 technical drawing 56 5 0 1 MIN 2 5 SECTION A A SECTION B B 9 4 0 05 SECTION C C CRITICAL DIMENSION 2 SURFACE TEXTURE VDI3400 12 SURFACE TEXTURE VDI3400 27 ALL FACES TEXTURED VDI3400 12 UNLESS OTHERWISE INDICATED NO SHARP EDGES ALLOWED 0 5 0 025 6X MIN 2 5 4x SECTION B B 3 5 0 05 2x 0 2 0 03 m I C m Pais B DETAIL C SCALE 5 1 2x 3 3 0 1 3X 0 1 3X SECTION A A 2x 4 0 05 4x SECTION D D C 3 CRITICAL DIMENSIONS ALL FACES TEXTURED VDI3400 12 NO SHARP EDGES ALLOWED Tolerances occ Moter iol 150 2768 ALUMINIUM 6060 Treatment Roughness acc ANODIZED RAL 7021 vOI3400 12 CAD drawings STEP are available at request via sales xsens com Document MTO605P E Xsens Techn
8. With the MTi 300 and MTi G 700 the effect of magnetic distortions will be lower than in the MTi 30 Also the choice for a filter profile greatly influences the total error amount because of the magnetic distortion Degaussing is a procedure to apply strong alternating magnetic fields with decreasing magnitude in random direction to an object that has been magnetized The effect of the strong alternating fields is to remove any magnetized aligned domains in the object When degaussing make sure the MTi is not attached to the object This type of disturbance is non deterministic Document MT0605P E Xsens Technologies B V 9 MTi User Manual 2 6 Typical User Scenarios This section is intended to help you find the right software component and corresponding documentation for the way you want to use your MTi 2 6 1 MT Software Suite The MT Software Suite is a set of software components that can be used to communicate with the MTi and to perform more high level routines such as logging exporting a magnetic field calibration and updating of the firmware Depicted below is a flow chart based on the software platform and the preferred interface level FW Updater mE Software Suite Updates MTi lt S u pport in g x Ld latest firmware a B applications MagFieldMapper Calibrates for 4 magnetic Communication options A distortions
9. Fisher pin no Molex pin no 3 10 pins header GND Black 1 2 4 8 RS232 TX RS422 2 TX Yellow 2 4 5 5232 RX 5422 Y TX Grey 3 5 3 Vin 4 5 30V Red 4 1 1 Syncin Blue 5 7 2 SyncOut Pink 6 9 6 ClockSync Brown 7 8 10 USB DP D R8422 A RX Green 8 3 9 USB DM D RS422 B RX White 9 6 7 6 3 1 3 GPS Antenna The MTi G 700 has an onboard GPS receiver that needs an active antenna This antenna can be connected to the SMA connector on the front panel of the MTi G 700 6 3 1 3 1 Not using the default PCTel 3910 D antenna When using another GPS antenna than the one supplied as a part of the MTi G 700 Development Kit one has to consider the antenna gain of the active antenna It is recommended to only use active antennas with gain between 15 50 dB The voltage supplied by the MTi G to the SMA or u fl connector OEM is 3 3V The maximum current must be under 7 5mA Patch antennas are not suitable for hand held devices because of the de tuning effect of the hand body The hand body will dielectrically load the patch antenna which will de tune the resonant frequency of the patch For this purpose a helix antenna is recommended In contrast to helix antennas patch antennas require a ground plane for operation Helix antennas can be designed for use with or without a ground plane Document MT0605P E Xsens Technologies B V 66 MTi User Manual 6 3 2 connections overview 6 3 2 1 Power dat
10. Max Typ Max Typ Max Typ Max Max Roll Pitch Static 0 29 0 4 02 0 4 0 22 0 25 0 2 0 25 0 2 0 25 Yaw Dynamic 0 5 2 0 0 5 2 0 0 32 1 09 0 39 1 02 0 39 1 09 Unref 1 0 N A Unref 1 09 N A 1 09 N A Performance specifications highly depend on the conditions The MTi Technical Datasheet TD containing validation tests and more details on the specifications of orientation and individual sensors is available The orientation performance of the MTi G 700 is valid in an increased range of applications and motions The performance specifications in this chapter are subject to the following assumptions see also footnotes Correct filter profile If an unsuitable filter profile is chosen the sensor fusion algorithm will use erroneous assumptions Depending on the specific situation this can lead to large errors or even instability of the filter Take care to select the correct filter profile If you are uncertain do not hesitate to contact Xsens or your local distributor Magnetic distortions In several filter profiles the on board 3D magnetometer is used to observe the heading It is assumed that a magnetic field mapping is performed and that the magnetometers are not distorted by nearby ferromagnetic materials in the environment Long lasting accelerations all except for MTi G 700 every filter profile copes different with long lasting accelerations Although the MTi s are able to
11. System AHRS 3 2 1 Using the acceleration of gravity to stabilize inclination roll pitch XKF3i stabilizes the inclination i e roll and pitch combined using the accelerometer signals An accelerometer measures gravitational acceleration plus acceleration due to the movement of the object with respect to its surroundings XKF3i uses the assumption that on average the acceleration due to the movement is zero Using this assumption the direction of the gravity can be observed and used to stabilize the attitude The orientation of the MTi in the gravity field is accounted for so that centripetal accelerations or asymmetrical movements cannot cause a degraded orientation estimate performance This assumption is surprisingly powerful almost all moving objects undergo accelerations if they are moving but in most cases the average acceleration with respect to the environment during some period of time is zero The key here is the amount of time over which the acceleration must be averaged for the assumption to hold During this time the rate gyroscopes must be able to track the orientation to a high degree of accuracy In practice this limits the amount of time over which the assumption holds true For the class of miniature MEMS rate gyroscopes used in the MTi 10 series this period of time is about 10 20 seconds maximum However for some applications this assumption does not hold For example an accelerating automobile may generate significant a
12. a unit vector n through an angle dis cos 5 nsin 5 A unit quaternion itself has unit magnitude and can be written in the following vector format Ais qo 94 92 93 Ig 1 Quaternions are an efficient non singular description of 3D orientation and a quaternion is unique up to sign q 9 An alternative representation of a quaternion is as a vector with a complex part the real component is the first one qo The inverse qs is defined by the complex conjugate of qus The complex conjugate is easily calculated dis 90 d d2 93 951 Please note that due to the definition of Euler angles there is a mathematical singularity when the sensor fixed x axis IS pointing up or down in the earth fixed reference frame i e pitch approaches 90 In practice this means roll and pitch is not defined as such when pitch is close to 90 deg This singularity is in no way present in the quaternion or rotation matrix output mode Document MT0605P E Xsens Technologies B V 32 MTi User Manual As defined here q s rotates a vector in the sensor co ordinate system S to the global reference co ordinate system L XL 915 5915 QrsXsQsr Hence qs rotates a vector in the global reference co ordinate system L to the sensor co ordinate system S where qszis the complex conjugate of qs 4 5 2 Euler angles orientation output mode Euler angles describe the rotation of a r
13. application Document MT0605P E Xsens Technologies B V 18 MTi User Manual 3 3 Xsens sensor fusion algorithm for MTi 100 series 3 3 1 100 series filter The Xsens sensor fusion algorithm in the MTi 100 series has several advanced features It can handle a multitude of data channels to incorporate GPS and barometer data as well 3 3 2 Transient accelerations The overall accuracy and robustness of the MTi 100 series is significantly higher than the overall accuracy of the MTi 10 series The most important factor contributing to this is the use of higher accuracy gyroscopes The gyroscopes in the MTi 100 series are vibration rejecting quad structure MEMS gyroscopes Because of the excellent bias stability it is possible to integrate the rate of turn for a long time requiring less frequent reference updates for orientation The Xsens sensor fusion algorithm can detect transient accelerations and will use the gyroscopes for a longer time Next to the better gyroscopes the MTi G 700 algorithm adds robustness to the orientation and position estimates making the MTi 100 series the better choice in more demanding applications 3 3 3 Magnetic distortions As with transient accelerations magnetic distortions are also detected by the sensor fusion algorithm in the MTi 100 series This makes it possible to use the magnetometers in periods of homogenous magnetic fields but discarding magnetometer updates when the magnetic
14. cos sin sing cos v P Ocoswy singsin cosW cosg sinW cos 9 sinO cos sing sin i sin sin cos COS cos As defined here Ais rotates a vector in the sensor co ordinate system S to the global reference system L RisX5 Xs It follows naturally that rotates a vector in the global reference co ordinate system L to the sensor co ordinate system S For the rotation matrix DCM output mode it is defined that g Ris c f i R32 Rag b c Rs 4 Ro Ros g h i R32 Rag Document MT0605P E Xsens Technologies B V 34 MTi User Manual 46 Sensor data performance specification This section describes the specifications of the physical sensors of the MTi s Not all MTi s feature all sensors Per sensor the applicable MTi s are mentioned For more detailed specifications refer to MTI TD 4 6 4 Gyroscopes The main difference between the MTi 10 series and the MTi 100 series is the type of gyroscopes used The two different specifications are listed below A full range of 1000 s is available upon request Gyroscopes in MTi 10 series MTi 10 MTi 20 MTi 30 Gyroscopes in MTi 100 series MTi 100 MTi 200 MTi 300 MTi G 700 Gyroscope specification MTi 10 series MTi 100 series Rate of turn Typical Max Typical Max Standard full range deg s
15. default the yaw output is 0 when the vehicle x axis of the MTi is pointing East When it is required that the yaw output is 0 when the vehicle x axis of the MTi is pointing North it is recommended to select NWU or NED as the reference coordinate system In section 4 11 the various alignment resets are described Note that for proper working of the MTi G in the automotive filter profile it is needed to mount the in such a way that the yaw indicates 0 deg in the direction of the vehicle For ENU coordinate systems without an alignment reset this means that the y axis of the MTi G should point to the front of the vehicle in NWU and NED coordinate systems that means that the x axis of the MTi G should point to the front of the vehicle EEE Standard for Inertial Systems Terminology Document MT0605P E Xsens Technologies B V 26 MTi User Manual True North vs Magnetic North As defined above the output coordinate system of the MTi is with respect to local Magnetic North The deviation between Magnetic North and True North known as the magnetic declination varies depending on the location on earth and can be roughly obtained from the World Magnetic Model Xsens uses WMM 2010 2015 of the earth s magnetic field as a function of latitude and longitude The MTi accepts a setting of the declination value This is done by setting the position in the MT Manager SDK or by direct communication with the sensor The outp
16. field is distorted Because of the superior gyroscopes in the MTi 100 series the heading will be drifting at a relatively low rate 3 3 4 Loss of GPS When the MTi G 700 GPS INS has limited mediocre GPS reception or even no GPS reception at all the MTi G 700 sensor fusion algorithm seamlessly adjusts the filter settings in such a way that the highest possible accuracy is maintained The GPS status will be monitored continuously so that the filter can take GPS data into account when available and sufficiently trustworthy In case loss of GPS lasts longer than 45 60 seconds exact time depends on the filter profile the MTi G 700 will go into a state where it no longer uses velocity estimates in the filter 3 3 5 100 series filter profiles Only the MTi G 700 GPS INS can use GPS updates the MTi 300 AHRS and MTi G 700 GPS INS use the magnetometers The MTi 200 only uses the inertial sensors The sensor fusion algorithm uses assumptions about the acceleration and the magnetic field to obtain orientation Because the characteristics of the acceleration or magnetic field differ for different applications the filter makes use of filter profiles to be able to use the correct assumptions given the application This way the filter can be optimized for different types of movement For optimal performance the correct filter profile must be set by the user Number Name Magnetometer Product 39 General 300 AHRS 40 High mag dep 300 AHR
17. in the following sections Serial MT SDK communication iver Note that conceptually XDA makes no distinction between the cases that the data source is real time data stream from a device or if it is a recorded file data stream Using the Xsens XBus low level communication protocol is discussed in section 2 6 4 ile Xsens Device management and global control functions Viotion Tracker are grouped in the XsControl object To access functionality for a specific device the XsDevice Figure 1 Xsens Device API object is available Typical steps are 1 Enter a serial key with XsControl setSerialKey Scan for Xsens devices with XsScanner scanPorts Open port with XsControl openPort and get device object with XsControl device Configure device with XsDevice functions Start measuring ee da Document MTO605P E Xsens Technologies B V 12 MTi User Manual C interface libraries XDA is implemented in two C interface libraries that are supplied for MS Windows and Linux consisting of two parts e XDA that contains the access to functionality as implemented in devices e g configuring the Motion Trackers requesting data etc Linux only available as beta via support xsens com e Xslypes that contains generic types vectors matrices quaternions etc and some basic operations on those types e g converting quaternions coming from the MTi into Euler angles The C API exposes all possible functions th
18. range of IO options The 100 series is a revolutionary new class of MEMS IMUSs 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 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 4 MTi 30 AHRS The MTi 30 AHRS is a full gyro enhanced Attitude and Heading Reference System AHRS It outputs drift f
19. the MTi G over the curved Earth surface if the MTi G has a velocity Therefore we can work with a local linearized tangent plane without making any significant errors Document MTO605P E Xsens Technologies B V 28 MTi User Manual This system is called the locally tangent plane LTP and is in fact local linearization of the Ellipsoidal Coordinates Latitude Longitude Altitude in the WGS 84 Ellipsoid When mapping the ellipsoidal coordinates defined by to latitude longitude and altitude to a local tangent plane a spatial distortion is introduced as shown in Figure 7 linearized meridian local meridian latitiide longitude Figure 7 Spatial Distortion as Result of Mapping Ellipsoidal Coordinates to Local Tangent Plane LTP In order to minimize the linearization error the reference coordinates should be chosen as close as possible to the points that are being mapped The MTi G performs a local linearization for each valid GPS update according to the following linearization scheme given a reference coordinates defined by a latitude longitude pair The height is the same for both coordinate systems E Aq cos 0 Where R is the radius of Earth at a given latitude A8 0 bref AQ Pref In this documentation we will refer to the WGS84 co ordinates system as G The output of position data from the MTi G is in Ellipsoidal Coordinates Latitude Lo
20. the right the Development Kit is shown containing an MTi USB cable Software Suite on USB flash drive a Quick Setup sheet and license key both in the lid The full content of the MTi DK is described below 2 1 1 X Contents e Your MTi e Device specific Test and Calibration Certificate e A letter with your individual software license code e USB cable CA USB MTi e Multi purpose cable CA MP MTi optional e Quick Setup Sheet e MT Software Suite on USB Flash Drive o Low level communication Documentation PDF MTO101P o Quick Setup PDF o MT Software Suite Xsens MTi USB driver MT Manager MT Software Development Kit MT SDK e XsensDeviceApi DLL 32 bit and 64 bit o DLL C and C interface o COM interface e XDA public source files C C wrapper e Example source code and examples o MATLAB DLL example supported from MATLAB 201 0b o example o C public source example and DLL example e Linux SDK beta release download from www xsens com Magnetic Field Mapper MFM Documentation e MTi User Manual MTO506P e MT Low level communication Documentation MT0101P e MT Magnetic Field Mapper Documentation MT0202P e XDA doxygen HTML API documentation NOTE the most recent version of the software source code and documentation can always be downloaded on the support section of www xsens com en support Document MTO605P E Xsens Technologies B V 7 MTi User Manual 2 5
21. the rotation matrix LSR the SDI data and SAv the calibrated data 5s and the sensor fusion algorithm output 4x L S L Lp SS p S Aq SAq53 Aq S Av SR Av Soe SR MEN b y E Dm Five methods are available to facilitate in obtaining the output in the desired coordinate frames which are 1 Aninclination reset that levels the sensor by defining the S frame A heading reset that defines the L frame by setting the x axis of L frame while maintaining the z axis along the vertical also known as bore sighting 3 Acombined inclination heading reset referred to as alignment reset 4 Setting an arbitrary alignment rotation matrix to rotate S to the chosen frame S SSR 5 Setting an arbitrary alignment rotation matrix to rotate L to the chosen frame L LLR The different orientation resets are explained using Figure 10 showing a side and top view of each of the resets with the standard orientation output SR Orientation resets The orientation reset functions aim to facilitate in aligning the sensor object it is strapped to by defining the L frame heading reset and the S frame inclination reset resulting in SR defined in the equations above The orientation reset is separated in an inclination reset leveling and a heading reset bore sighting After a full orientation reset the orientation of the L and S frames are equal and the coordinate axes are defined by the L a
22. to the specifications please contact Xsens or your local distributor www xsens com support Document MT0605P E Xsens Technologies B V 76 MTi User Manual 7 4 CE Declaration of Conformity for the MT devices We Xsens Technologies BV of Pantheon 6a 7521 PR Enschede The Netherlands declare under our sole responsibility that our products MTi 10 A G MTi 20 A G MTi 30 A G MTi 100 A G MTi 200 A G MTi 300 A G MTi G 700 A G MTi 10 2A5G4 MTi 10 2A5G0 MTi 10 4A5G4 MTi 10 4A5G0 MTi 10 6A5G4 MTi 10 6A5G0 MTi 10 2A8G4 MTi 10 2A8G0 MTi 10 4A8G4 MTi 10 4A8G0 MTi 10 6A8G4 MTi 10 6A8G0 MTi 20 2A5G4 MTi 20 2A5G0 MTi 20 4A5G4 MTi 20 4A5G0 MTi 20 6A5G4 MTi 20 6A5G0 MTi 20 2A8G4 MTi 20 2A8G0 MTi 20 4A8G4 MTi 20 4A8G0 MTi 20 6A8G4 MTi 20 6A8G0 MTi 30 2A5G4 MTi 30 2A5G0 MTi 30 4A5G4 MTi 30 4A5G0 MTi 30 6A5G4 MTi 30 6A5G0 MTi 30 2A8G4 MTi 30 2A8G0 MTi 30 4A8G4 MTi 30 4A8G0 MTi 30 6A8G4 MTi 30 6A8G0 MTi 100 2A5G4 MTi 100 2A5G0 MTi 100 4A5G4 MTi 100 4A5G0 MTi 100 6A5G4 MTi 100 6A5G0 MTi 100 2A8G4 MTi 100 2A8G0 MTi 100 4A8G4 MTi 100 4A8G0 MTi 100 6A8G4 MTi 100 6A8G0 MTi 200 2A5G4 MTi 200 2A5G0 MTi 200 4A5G4 MTi 200 4A5GO0 MTi 200 6A5G4 MTi 200 6A5G0 MTi 200 2A8G4 MTi 200 2A8G0 MTi 200 4A8G4 MTi 200 4A8G0 MTi 200 6A8G4 MTi 200 6A8G0 MTi 300 2A5G4 MTi 300 2A5G0 MTi 300 4A5G4 MTi 300 4A5G0 MTi 300 6A5G4 MTi 30
23. 0 4 OUTPUT SPECIFICATION ES esM EIC NE M REESE dM 22 Ar OVER WE Or OAT OUTPUTS la usce E 23 4 1 1 MTData2 output in XBus 23 Ae iz DV OL OC OF 24 Document MIO605P E Xsens Technologies B V li MTi User Manual 4 2 COORDINATE SYSTEMS 1 5 25 4 2 1 Calibrated inertial data and magnetic field data 25 42 2 Dela and delta VeloGibyiiiseexic tuta Ene ENRERE NNER Pea 25 42 3 Orientation data 26 S E 2 425 Io Toa QOL RTT 2 4 3 ORIENTATION PERFORMANCE SPECIFICATION ccecceccecceccecceccecceececaeceecseeseeceeeeeseeseeseeseeseeseeseeseesaeseeseesaeees 30 4 4 POSITION AND VELOCITY PERFORMANCE SPECIFICATION 700 31 45S ORENTATON OUTPUT MODES c 31 4 5 1 Quaternion orientation output 32 4 5 2 Euler angles orientation output mode 33 4 5 3 Rotation Matrix orientation output 33 4 6 SENSOR DATA PERFORMANCE SPECIFICATION eeeseeee nennen nenne nnn nenne ni sese
24. 0 6A5G0 MTi 300 2A8G4 MTi 300 2A8G0 MTi 300 4A8G4 MTi 300 4A8G0 MTi 300 6A8G4 MTi 300 6A8G0 MTi G 700 2A5G4 MTi G 700 2A5G0 MTi G 700 4A5G4 MTi G 700 4A5G0 MTi G 700 6A5G4 MTi G 700 6A5G0 MTi G 700 2A8G4 MTi G 700 2A8G0 MTi G 700 4A8G4 MTi G 700 4A8G0 MTi G 700 6A8G4 MTi G 700 6A8G0 to which this declaration relates are in conformity with the essential requirements of the EMC Directive 2004 108 EC and the following Standards and other Normative Documents EMC Directive 2004 108 EEC EN 61326 1 2006 EN 61000 3 2 2006 EN 61000 3 3 1995 A1 2001 A2 2005 Environment to be used is light industrial laboratory Class of emission is B performance criterion B Jan 174 2014 Enschede the Netherlands Per Slycke CTO Xsens Technologies Document MTO605P E Xsens Technologies B V 77 MTi User Manual 7 5 FCC Declaration of Conformity for the MT devices We Xsens Technologies BV of 7521 PR Enschede The Netherlands C Pantheon 6a declare under our sole responsibility that our products MTi 10 A G MTi 10 2A5G4 MTi 10 2A5G0 MTi 10 4A5G4 MTi 10 4A5G0 MTi 10 6A5G4 MTi 10 6A5G0 MTi 10 2A8G4 MTi 10 2A8G0 MTi 10 4A8G4 MTi 10 4A8G0 MTi 10 6A8G4 MTi 10 6A8G0 MTi 20 A G MTi 20 2A5G4 MTi 20 2A5G0 MTi 20 4A5G4 MTi 20 4A5G0 MTi 20 6A5G4 MTi 20 6A5G0 MTi 20 2A8G4 MTi 20 2A8G0 MTi 20 4A8G4 MTi 20 4A8G0 MTi 20 6A8G4 MTi 20 6A8G0 MTi 30 A G M
25. 34V Use only SELV Separated or Safety extra low voltage power supplies double isolated that are short circuit proof he average operating power consumption is 530mW 106 mA 9 5V for the MTi 10 series The average power consumption may vary slightly with usage mode DSP load e he peak current at startup power on can be to 200mA e When operated in room temperature the temperature inside the sensor will be 35 40 C in normal conditions 2 Increasing baud rate from 115k2 to 460k8 will decrease 10 in power consumption for all configurations Please note that efficiency of the power input stage will decrease with increasing supply voltage 13 If an alternative power supply is used check if it can supply these peak currents Do not use a power supply if the peak supply current is lower than stated Document MTO605P E MTi User Manual O Xsens Technologies B V 63 6 2 1 Alternative 3V3 power supply From hardware revision 2 0 the OEM version of the MTi operates on 3V3 The 3V3 power supply can be used when e there is only 3V3 available e there are constraints on the power usage 3V3 reduces the power usage with 20 The hardware of the MTi is designed in such a way that power is automatically drawn from either the standard VCC 4 5 34V or the alternative 3V3 power When there is a voltage applied both to the standard VCC and the alternative 3V3 the MTi will not start up and may be damaged Refe
26. 9 ms no sync pulse and so on The data output e g orientation and frequency is irrelevant for the functionality of Interval Transition Measurement A SyncOut marker is outputted in the data stream that shows the exact time of the transmission of the SyncOut pulse The signal can be set to either pulse or toggle mode and in case of pulse mode the polarity can be set to negative or positive For more information about enabling SyncOut and its settings see LLCP To connect the SyncOut signal to an external device you can either make a custom cable that wires the SyncOut pin see section 6 3 1 2 directly from the MTi MTi OEM or in case you use the CA MP MTI cable you can connect directly to the appropriate pin of the Molex header MTi data and comms e g orientation Trigger Images NOTE Always check if the input voltage levels and the input impedance of the external device matches the SyncOut specifications Document MTO605P E Xsens Technologies B V 58 MTi User Manual 5 5 4 Clock synchronization Clock Bias Estimation The MTi features clock synchronization it is possible to adjust the bias of the MTi s internal clock with an external clock of which the frequency is known Note that the adjusted bias is also used in the calibration of the inertial sensors so that no additional errors are introduced When a pulse is missed e g because it was not sent or was lost on the input line this will not have
27. A53G35 Legacy MTi OEM The OEM board of the legacy MTi Introduced The board is green contrary to 2006 orange MTi 10s and MTi 100s OEM Available at board least till Dec 2013 Legacy MTx Designed as a Motion Tracker for Introduced human movements this low weight 2005 Motion Tracker has a fully plastic Available at casing Product codes are in the form least till Dec of MTx 28A53G25 2013 Legacy MTi G The GPS aided MTi G offers reliable Introduced orientation during accelerations The 2007 C successor of the MTi G is the MTi G Available at 7 00 The casing is as the legacy least till Dec MTi s casing Product codes are in 2013 the form of MTi G 28A53G35 MTw The wireless MTw is available as Introduced single Motion Tracker or in a time 2010 synchronized network together with the Awinda station Product codes are in the form of MTw 38A70G20 MTi 10 series The latest 4 generation addition to Introduced MTi 100 series the Motion Trackers of Xsens MkIV 2012 including MTi G See section 2 1 and 2 2 for more 700 and OEM information The OEM board is orange This manual focuses on these products Product codes are in the form of e g MTi 30 2A5G4 Document MT0605P E Xsens Technologies B V 6 MTi User Manual 2 4 Overview MTi Development Kit The MTi development kit is a very easy to use starter s kit that allows for fast and easy integration of the MTi in any user scenario On
28. AC E 76 7 3 NO 76 7 4 DECLARATION OF CONFORMITY FOR THE MT DEVICES 77 7 5 FCC DECLARATION OF CONFORMITY FOR THE DEVICES 18 ZO WARRANTY VV EU DURER asia FUGA ERU Vid GU tad NER 79 77 CUSTOMER SUPPORT EEEE 19 Document MTO605P E Xsens Technologies B V V MTi User Manual 1 References 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 Document MT0605P E Xsens Technologies B V 2 MTi User Manual 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
29. Counter XDI Itow XDI GpsAge PressureAge XDI SampleTimeFine XDI SampleTimeCoarse FrameRange XDI OrientationGroup XDI Quaternion XDI RotationMatrix XDI EulerAngles XDI PressureGroup XDI BaroPressure XDI AccelerationGroup XDI DeltaV XDI_ Acceleration XDI FreeAcceleration XDI IndicationGroup XDI Triggerln XDI Triggerln2 XDI PositionGroup XDI AltitudeMsl XDI AltitudeEllipsoid XDI PositionEcef 08x0 081y 10x0 1010 1020 1030 1040 1050 1060 1070 1080 20xy 201y 202y 203y 30xy 301y 40xy 401y 402y 403y 4800 4810 4820 50xy 501y 502y 503y Tm NJS e IS e ee 1Hz 2000 Hz 400 Hz 50 Hz 2000 Hz e o o o e o o o For MTw only MTi see StatusWord For MTw only MTi see StatusWord For MTw only MTi see StatusWord 400 Hz e e Maximum frequencies may differ on the chosen combination of outputs Availability and frequency of outputs may differ between onboard processing and processing in XDA as SCR or delta q delta v is needed for processing data Document MTO605P E O Xsens Technologies B V 23 MTi User Manual LatLon Angular Velocity Rate of Turn Delta Q GPS DOP SOL Time UTC SV Info Sensor Component Readout SCR GYR MAG temperature Gyro temperatures Magnetic Magnetic Field Velocity Velocity XYZ Status Status Byte Status Word RSSI
30. G 700 is partly estimated by the on board barometer It is assumed that the pressure near the MTi G reflects the atmospheric pressure outside of the vehicle So if you selected a filter profile that uses barometer data the MTi G cannot be used in e g a pressurized cabin Furthermore the height accuracy may reduce with very rapid changes in atmospheric pressure that could occur in e g severe thunderstorms 4 4 Position and velocity performance specification MTi G 700 accelerations Based on the rate gyros the attitude and heading estimates will degrade slowly typically a degree every minute e Valid holonomic constraints MTi G 700 only In several filter profiles of the MTi G 700 it is assumed that the x axis of the MTi G is mounted in the driving direction of the vehicle If this is not the case within about 1 degree the estimated heading and position specification may not The MTi G 700 has the ability to output position The performance highly depends on the GPS availability placement of the GPS antenna etc The table below states the position and velocity accuracy according to Xsens reference trajectories as explained in MTI TD Parameter Position Velocity Data source AHRS augmented 400 Hz GPS INS SBAS GPS receiver 4 Hz GPS navigation solution SBAS AHRS augmented 400 Hz GPS INS GPS receiver 4 Hz GPS navigation solution 4 5 Orientation output modes The orientation as calculated by the MTi
31. G3 x az y 7 With O representing higher order models and temperature modelling g sensitivity corrections etc Each individual MTi is modeled for temperature dependence of both gain and bias for all sensors and other effects This modeling is not represented in the simple model in the above equations but is implemented in the firmware The basic indicative parameters in the above model of your individual MTi can be found on the MT Test and Calibration Certificate and in the MT Manager MT Settings dialog Document MT0605P E Xsens Technologies B V 40 MTi User Manual 4 9 2 Calibrated delta q and delta v outputs This output is coning and sculling compensated strap down integrated data in the sensor fixed coordinate system S or O Note that the value of the output depends on the output frequency as the values are integrated over a specific time Delta q can also be noted as dq delta angle del q or Orilnc Delta v can also be noted as dv delta velocity del v or Vellnc Output Unit Delta q DatalD 0x8030 a u quaternion values Delta v DatalD 0x4010 m s It is possible to multiply consecutive delta values to find the total orientation change over a specific period Note that this data is not drift free as it has not been processed by the sensor fusion filters Use the orientation output for drift free orientation 4 9 3 Calibrated inertial and magnetic data outputs Output of calib
32. Installation 2 5 1 Transient accelerations The 3D linear accelerometers in the MTi are primarily used to estimate the direction of gravity to obtain a reference for attitude pitch roll During long periods more than tens of seconds of transient free accelerations i e 2 derivative of position the observation of gravity cannot be made The sensor fusion algorithms take these effects into account but nonetheless it is impossible to estimate true vertical without added information The impact of transient accelerations can be minimized when you take into account a few things when positioning the device when installing it in the object you want to track navigate stabilize or control If you want to use the MTi to measure the dynamics of a moving vehicle craft it is best to position the measurement device at a position where you expect the least smallest transient accelerations This is typically close to the centre of gravity CG of the vehicle craft since any rotations around the centre of gravity translate into centripetal accelerations at any point outside the point of rotation which is usually close to the CG The acceleration of the vehicle as a whole can of course not be taken into account For the MTi G 700 however that have a valid GPS fix transient accelerations make the orientation better observable The MTi 100 series cope better with transient free accelerations because of the higher class gyroscopes in the MTi 100 s
33. LA or Software License Agreement that you need to read and accept In the following table the guidelines for use of each component are described Component EULA SLA Guidelines MT Manager EULA For use with Xsens products only Not allowed to re distribute Not allowed to reverse engineer Not allowed to modify Serial key required MT SDK SLA For use with Xsens products only Allowed to re distribute as is or embed in programs Not allowed to reverse engineer Allowed to modify and extend source code not allowed to modify DLL Serial key required for use of DLL not needed for source code Include Software License Agreement with distribution MT MFM SLA For use with Xsens products only Allowed to re distribute as is Not allowed to reverse engineer Not allowed to modify No serial key required Include Software License Agreement with distribution MT FWU SLA For use with Xsens products only Allowed to re distribute as is Not allowed to reverse engineer Not allowed to modify No serial key required Include Software License Agreement with distribution Document MTO605P E Xsens Technologies B V 15 MTi User Manual 3 System Overview 3 1 Calibration A correct calibration of the sensor components inside the MTi is essential for an accurate output Because of the importance of the calibration each Xsens MTi is calibrated and tested by subjecting each product to a wide range of motions and temperatur
34. N ISDEM MEME MM MUNI NM ENFIN MM 3 MEE RU ccr 3 2 1 1 o ee 3 2 1 2 IVT scrotal ark ack spe ne bn es cede ee eee acne nodes 3 2 1 3 IT TA I Faces sce 3 22 MT POE R 4 2 2 1 GS IN 4 2 2 2 MEU EP Rm 4 2 2 3 IT OVR 4 2 2 4 IVT OO IIS cos 4 2 2 5 Identifying device functionality using the unique Device Identifier 5 768 lt n EA 5 2 3 EVOLUTION OF MTI 2231 B Ol cae ee eee ee 6 Ze OVERVIEW MTI DEVELOPMENT KIT wsonsriaccescnsneaaseaoseucesaweqeaneacneworsavaaedviauseuansest E A 7 XEM ucro 8 2 5 1 Tre nc celer at lOS DM IM EI MR MEI MAE E EE 8 VS M ME o geo e EE AE 8 2 5 3 Magnetic materials and magnets 9 26 TYPICAL USER SCENARIOS 10 VEM MEE s oe CEU 10 2 6 2 Getting Started with the MT 11 2 6 3
35. N A The barometer features barometric atmospheric pressure The MTi 100 series feature this barometer The MTi 100 series has three holes with a protective vent in its casing in order to ensure fast adaptation inside the MTi to atmospheric pressure Typical latency because of the vent is 10 ms Barometer MTi 100 series only MTi 100 MTi 200 MTi 300 MTi G 700 Barometer specification Barometric pressure Full range hpa N A Noise density hpa VHZz 300 1100 0 01 Document MTO605P E O Xsens Technologies B V 36 MTi User Manual 4 6 4 GPS receiver The MTi G 700 is the only MTi that features a GPS receiver It requires an active antenna which is delivered with the Development Kit and can be ordered separately from Xsens as well It is possible to use a different antenna that better suits your application GPS Receiver specification Receiver Type Datum reference frame GPS Update Rate Horizontal Accuracy Position SPS SBAS Vertical Accuracy Position SPS Velocity accuracy Start up Time Cold start Re acquisition Tracking Sensitivity Timing Accuracy Maximum Altitude Maximum Velocity Max dynamics GPS MTi 100 series 50 channels GPS L1 C A code WGS84 ITRF2004 4 Hz 2 5m CEP 2 0 m CEP 5m 0 1 m s 30 m s 275 1s 161 dBm 30 ns RMS 18 km 515 m s 4g Note that when you are not using the default GPS antenna it is important to use an antenna
36. NEGLIGENCE STRICT LIABILITY OR OTHER THEORY WILL BE LIMITED EXCLUSIVELY TO PRODUCT REPAIR REPLACEMENT OR IF REPLACEMENT IS INADEQUATE AS A REMEDY OR IN XSENS OPINION IMPRACTICAL TO REFUND THE PRICE PAID FOR THE PRODUCT XSENS DOES NOT WARRANT GUARANTEE OR MAKE ANY REPRESENTATIONS REGARDING THE USE OR THE RESULTS OF THE USE OF THE PRODUCT OR WRITTEN MATERIALS IN TERMS OF CORRECTNESS ACCURACY RELIABILITY OR OTHERWISE Xsens shall have no liability for delays or failures beyond its reasonable control 7 7 Customer Support Xsens is glad to help you with any questions you may have about the MTi or about the use of the technology for your application Please use the FAQ contact Xsens distributor or if you are a direct customer of Xsens our Customer Support Internet and FAQ http www xsens com support gt Distributror network http www xsens com en company pages company distributors Telephone EMEA Pacific 31 0 88 9736700 31 88 XSENS 00 gt telephone US Los Angeles CA 1 310 481 1800 To be able to help you please mention your Motion Tracker Device ID on the side of the device and software license registration number in your e mail Document MT0605P E Xsens Technologies B V 79 MTi User Manual
37. Netherlands Per Slycke CTO Document MT0605P E Xsens Technologies B V 78 MTi User Manual 7 6 Warranty and liability Xsens Technologies B V warrants the products manufactured by it to be free from defects in material and workmanship for a period of 1 year from the date of delivery Products not subjected to misuse will be repaired replaced or credit issued at the sole option of Xsens Technologies B V Contact Xsens via www xsens com support for return material authorization RMA prior to returning any items for calibration repair or exchange The product must be returned in its original packaging to prevent damage during shipping The warranty shall not apply to products repaired or altered or removed from the original casing by others than Xsens Technologies B V so as in Xsens Technologies B V opinion to have adversely affected the product products subjected to negligence accidents or damaged by circumstances beyond Xsens Technologies B V s control NOTE Xsens reserves the right to make changes in its products in order to improve design performance or reliability Subject to the conditions and limitations on liability stated herein Xsens warrants that the Product as so delivered shall materially conform to Xsens then current specifications for the Product for a period of one year from the date of delivery ANY LIABILITY OF XSENS WITH RESPECT TO THE SYSTEM OR THE PERFORMANCE THEREOF UNDER ANY WARRANTY
38. PUT nenne nn nni ni ia ia ia ssa se se ie sese sse sese sui snas 47 72 A COU TCI G 4 ae eae E 4 4212 3 TimestampisSample Time 4 4 12 4 Setting UTC time on non GPS 5 47 S NIS MES YE Iam R 48 5 BASIC COMMUNICATION UNE SN Una EM EUM CEN NN MM MEN da E ad EN NE NNUS REN EUN EN UE 50 SV cte 50 D vio nitd E 50 51 SES MEE I dotium 51 ES MEE VU eL cane Pe nn ee rere 52 0 sect rece 53 5 4 COMMUNICATION TIMING csesesseeeeenee nennen nennen nenne ner ne re sii ui ia ia sa se re sese sse snas 54 5 5 TRIGGERING AND SYNCHRONIZATION aa 57 5 5 1 X External device triggers Send Latest 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
39. S 41 Dynamic 300 AHRS 42 Low mag dep 300 AHRS 43 VRU_ general 300 AHRS 200 VRU Document MT0605P E Xsens Technologies B V 19 MTi User Manual These are the same filter profiles as the MTi 10 series but they are differently tuned in the MTi 100 series to make better use of the gyroscopes and calibration For descriptions on these filter profiles refer to section 3 2 4 3 3 6 MTi G 700 filter profiles The MTi G 700 GPS INS uses different filter profiles as it is typically used in outdoor applications These filter profiles are described below Please note the specific cautions with each of these filter profiles Nr Name IMU Magnetic Barometric GPS Holonomic Product field pressure constraints 1 General 700 GPS INS 2 GeneralNoBaro 700 GPS INS 3 GeneralMag 700 GPS INS 4 Automotive 700 GPS INS 5 Automotive 700 GPS INS UrbanCanyon The General filter profile is the default setting It makes few assumptions about movements Yaw is referenced by comparing GPS acceleration with the on board accelerometers so the more movement when GPS is available will result in a better yaw Altitude height is determined by combining static pressure GPS altitude and accelerometers The barometric baseline is referenced by GPS so during GPS outages accurate height measurements are maintained because this barometric baseline is monitored The GeneralNoBaro filter profile is ver
40. SB6 USB converter cable Only case of an RS422 interface CA USB6 swap wires and 5 of the MTi MkIV multi plug cable CA MP MTI Grey and Green Remove the cable of the legacy MTi and connect the modified MTi MkIV cable MP MTI in the 9 pins Molex receptacle Atthe 7 pins receptacle of the USB converter the following connections are now available Wire Molex recept Functionality Functionality Functionality color pin no CA USB2 MTI 5 4 CA USB6 MTI Red 1 Vin 4 5 34V Vin 4 5 34V Vin 4 5 34V Black 2 GND GND GND Green 3 USB DP D USB DP D RS422 Y Yellow 4 RS232 TX RS485 TX RS422 Z Grey RS232 RX RS485 RX RS422 A White 6 USB DM D USB DM D RS422 B Blue 7 Active Syncin Active Syncin Active Brown 8 Clock sync In Clock sync In Clock sync In Pink 9 Sync IN OUT Sync IN OUT Sync IN OUT Pin 8 and 9 are only accessible by removing the two wires brown pink from the 9 pins connector Pin 1 of 7 pins Molex Pin 1 of 7 pins Molex Pin 1 of 9 pins Molex Pin 1 of 9 pins Molex USB converter with cable of legacy MTi USB converter with cable of MTi attached MkIV attached Document MTO605P E Xsens Technologies B V 70 MTi User Manual 6 4 Housing mechanical specifications The top casing of the MTi is made of anodized Aluminum 6060 The bottom plate is made of anodized Aluminum 6060 The MTi connector socket and housing assembly features rubber O ring se
41. This supersedes SetPeriod SetOutputSkipFactor SetOutputMode and SetOutputSettings The data is a list of maximum 32 data identifiers combined with a desired output frequency The response message contains a list with the same format but with the values actually used by the device Each entry in the list contains Offset Value 0 Data Identifier 2 bytes 2 Output Frequency 2 bytes A full list of all Data Identifiers can be found in the MT Low Level Communication Protocol documentation under SetOutputConfiguration GoToMeasurement MID 16 0x10 Data field n a Direction To MTi Valid in Config State Switches the active state of the device from Config State to Measurement State The current configuration settings are used to start the measurement MTData2 MID 54 0x36 DATA DATA length variable Direction To host Valid in Measurement State The MTData2 message contains output data according the current OutputConfiguration Unlike the legacy MTData message an MTData2 message does not have to contain all configured output all the Document MT0605P E Xsens Technologies B V 53 MTi User Manual time Instead of a single fixed output format for a particular configuration MTData2 message consists of one or more packets each containing a specific output The layout of an MTData2 message is shown below XBus Packet 1 Packet 2 Packet N CS header XBus Header The payload of the me
42. Ti 30 2A5G4 MTi 30 2A5G0 MTi 30 4A5G4 MTi 30 4A5G0 MTi 30 6A5G4 MTi 30 6A5G0 MTi 30 2A8G4 MTi 30 2A8G0 MTi 30 4A8G4 MTi 30 4A8G0 MTi 30 6A8G4 MTi 30 6A8G0 MTi 100 A G MTi 100 2A5G4 MTi 100 2A5G0 MTi 100 4A5G4 MTi 100 4A5G0 MTi 100 6A5G4 MTi 100 6A5G0 MTi 100 2A8G4 MTi 100 2A8G0 MTi 100 4A8G4 MTi 100 4A8G0 MTi 100 6A8G4 MTi 100 6A8G0 MTi 200 A G MTi 200 2A5G4 MTi 200 2A5G0 MTi 200 4A5G4 MTi 200 4A5GO0 MTi 200 6A5G4 MTi 200 6A5G0 MTi 200 2A8G4 MTi 200 2A8G0 MTi 200 4A8G4 MTi 200 4A8G0 MTi 200 6A8G4 MTi 200 6A8G0 MTi 300 A G MTi 300 2A5G4 MTi 300 2A5G0 MTi 300 4A5G4 MTi 300 4A5G0 MTi 300 6A5G4 MTi 300 6A5G0 MTi 300 2A8G4 MTi 300 2A8G0 MTi 300 4A8G4 MTi 300 4A8G0 MTi 300 6A8G4 MTi 300 6A8G0 MTi G 700 A G MTi G 700 2A5G4 MTi G 700 2A5G0 MTi G 700 4A5G4 MTi G 700 4A5G0 MTi G 700 6A5G4 MTi G 700 6A5G0 MTi G 700 2A8G4 MTi G 700 2A8G0 MTi G 700 4A8G4 MTi G 700 4A8G0 MTi G 700 6A8G4 MTi G 700 6A8G0 to which this declaration relates have been tested and found to comply with the limits for a Unintentional Radiator as described in 47 CFR 15 2007 May 04 Edition Class B Digital Device pursuant to Part 15 of the FCC Rules Operation is subject to the following two conditions 1 This device may not cause harmful interference and 2 his device must accept any interference received including interference that may cause undesired operation Jan 174 2014 Enschede the
43. Using the Software Development Kit SDK 12 2 6 4 Direct low level communication with MT 14 265 X Migration from MT SDK 3 3 CMT E Fea Ex a RR Rex FERAE 14 2 66 Terms of use MI Software Suite Hbc ETE 15 3 ME SYSTEM OVERVIEW 16 01 AORA ON E P 16 3 2 XSENS KALMAN FILTER FOR MTI LO SERIES lsesseseseen Hmmm nmn nennen nennen nemen nnns 16 3 2 1 Using the acceleration of gravity to stabilize inclination roll pitch eene 16 3 2 2 Using the Earth magnetic field to stabilize yaw 17 LU MER pns NR 17 32A ME 17 3 3 XSENS SENSOR FUSION ALGORITHM FOR MTI LOO SERIES essesseeseeeee nennen nnne nennen nnne nnns 19 2334 MEH100 s6ries Iler 19 332 Tamen accelerat lof S 19 423 Magnell dISstOFLOHS ead 19 S550 2280809752 O ee ne er eee A ee ee 19 3 3 5 MTi 100 series filter profiles 19 32290 MTi G 700 filter profiles acters cs aw ees ccc waste EEEE EE AS 2
44. WGS84 is also what is used in the MTi G WGS84 provides an ellipsoidal model of the Earth s shape as well as Earth s gravitational irregularities Major parameters are the semi major axis a 26 378 137 m and the semi minor axis b 26 356 752 m see figures below There are several local models datums which will increase local accuracy using modified a and b and shift parameters x y z of the origin However if a selected datum is used beyond its borders accuracy will deteriorate fast The MTi G uses the default WGS84 model and not a specific datum Earth Centered Earth Fixed ECEF WGS 84 parameters a 6 378 317 meter b 2 6 356 752 meter ZA North pole Ellipsoid Equatorial plane Origin v lt Greenwich Meridian Equator x amp Figure 5 Earth Centered Earth Fixed Coordinate System Spherical coordinates LLA longitude Q latitude h altitude 2 North pole Ellipsoid Equatorial plane Y Greenwich Meridian Equator Figure 6 Definition of Ellipsoidal Coordinates Latitude Longitude Altitude in WGS 84 Ellipsoid In order to combine the output of the GPS receiver with the IMU both systems have to be converted to an appropriate coordinate system Inertial sensors measure properties in the system However the MEMS inertial sensors used in the MTi G are not accurate enough to measure the Earth s rotation rate or the transport rate of
45. a All MTi s are available as OEM board as well The connection from the OEM board to the push pull connector of the encased version is a flexible PCB which has put to vibration test according to MIL STD 202 The OEM board contains two headers one 10 pins header and one 14 pins header Details of the headers are 5x2 10 pins dual row box header pitch 1 27 mm FTS 105 01 F DV P K 7x2 14 pins dual row box header pitch 1 27 mm FTS 107 01 F DV P K The two headers both have several functions of which some are reserved for future use The 10 pins header offers basic functionality the 14 pins header features advanced options Note that MTi s with an RS422 interface don t have a USB interface USB DP D RS422 A RI USB DP Ds _ _ _ d Pin 1 and 10 of the 10 pins header and pin 1 and pin 14 of the 14 pins header are labelled on the PCB E 1311 9 75 3 1 14 121086 4 2 14 3V3 available from hardware version 2 0 Document MT0605P E Xsens Technologies B V 67 MTi User Manual Start up procedure The MTi starts up with communication over the serial RS232 RS485 RS422 interface by default If alternative UART is set the MTi will switch to alternative UART f USB is detected the MTi will switch to USB communication WakeUp message sent f WakeUp is not interrupted the MTi will be put in Measurement Mode Plugging in USB at any time will
46. a bad influence on the performance The maximum time that the pulses may be absent is 30 seconds The clock synchronization can be used for two distinctive use cases e When a precise external clock is available e g a GPS time pulse this frequency can be sent to the MTi to make sure that the time of the MTi follows the UTC time e When an external device has a time constant that differs from the MTi the sensor readings will at some point no longer be aligned to each other If the external device accepts synchronization pulses it is possible to use SyncOut if the external device can send synchronization pulses at a frequency that is the same as the required output frequency of the MTi it is possible to use Syncln If these two options are not possible the Clock Sync is an alternative Specification Value MTi s internal clock accuracy 10 ppm Input frequency 0 1 1000 Hz Maximum deviation from MTi s internal clock 900 ppm Initialisation time per ppm difference between 0 72 ms ppm internal clock and external clock 5 5 4 1 Clock Bias Estimation from GPS The MTi G 700 GPS INS uses the clock bias estimation function to synchronize the MTi G with the GPS time 1 ppm This synchronization is set by default and although not recommended it is possible to disable this synchronization setting 5 5 5 StartSampling One of the advanced timing features of the MTi is the StartSampling synchronization function StartSampling will trigger t
47. abilization of the heading and assumes very short magnetic distortions Typical applications are where the MTi is mounted on persons or hand held e g HMD sports attributes etc The low mag dep filter profile assumes that the dynamics is relatively low and that there are long lasting external magnetic distortions Also use this filter profile when it is difficult to do a very good Magnetic Field Mapping MFM The use of the low mag dep filter profile can be useful to limit drift in heading whilst not being in a homogenous magnetic field Typical applications are large vessels and unmanned ground vehicles in buildings The VRU general filter profile assumes moderate dynamics in a field where the magnetic field cannot be trusted at all It is also possible to use this filter profile in situations where an alternative source of yaw is available Yaw from the VRU is unreferenced note however that because of the working principle of the VRU the drift in yaw will be much lower than when gyroscope signals would be integrated Typical applications are stabilized antenna platforms mounted on cars of ships and pipeline inspection tools This filter profile is the only one available for the MTi 20 VRU Every application is different and although example applications are listed above results may vary from setup to setup It is recommended to reprocess recorded data with different filter profiles in MT Manager to determine the best results in your specific
48. aling The MTi 100 series feature a vent that allows for the inside pressure to be the same as the ambient pressure without compromising the ingress protection 6 4 1 Environmental protection of the housing All encased MTi s are designed to withstand usage in application where dust and occasional water splashing can be expected However Xsens in house testing has confirmed that the casing and connector can withstand temporary environmental circumstances equivalent to Protection Classification IP67 sealed against dust 30 minutes immersion at depth of 1 m 6 4 2 Dimensions The MTi 10 series and the MTi 100 series including MTi G 700 have an identical footprint and position of the connector Differences in casings are limited to colour barometer holes MTi 100 series only and SMA connector MTi G 700 only 6 4 3 Mounting the MTi OEM The MTi OEM has four mounting holes holes for M1 6 screws In order to lower and tighten the screws it is convenient to use a piece of heat shrink tube placed over the holes S airg Figure 11 Using a heat shrink tube to position the mounting screws Document MT0605P E Xsens Technologies B V 71 MTi User Manual 6 4 4 10 series technical drawing 56 5 0 1 CRITICAL DIMENSION 2 SURFACE TEXTURE VDI3400 12 SURFACE TEXTURE VDI3400 27 9 4 0 05 ALL FACES TEXTURED VDI3400 12 UNLESS OTHERWISE INDICATED NO SHARP EDGES ALLOWED
49. and synchronization In case multiple systems are used during a measurement it is important to have the measurement data synchronized between the systems Processing synchronised data is much easier because there is no need to resample the data to compensate for timing inaccuracies like clock drift and clock deviations Synchronization using multiple systems involves 2 important issues starting the measurement at the same time and having a fixed time relationship of the sampling instances This section will explain how the MTi must be setup when using multiple measurement systems All MTi s have a minimum of 3 GPIOs offering the MTi capabilities to be triggered by external devices trigger external devices or synchronize clock drift These three user scenarios are explained in the following subsections 5 5 1 External device triggers MTi Send Latest In the following figure a possible configuration is shown where a Motion Tracker and Device A are synchronised In this example a clock generator triggers device A and an MTi ensuring that the two devices are synchronized with each other MTi data and comms e g orientation The output of the clock generator can be directly connected to the MTi NOTE Always check if the Syncln specification matches with the trigger signal Once a Syncln signal or a ReqData message is received the MTi will output the latest available data It is possible to delay the data to be sent to choo
50. at could be supported by an Xsens device As such a certain functionality implemented in devices is accessible by a function call that takes at least an XsDevice Object as a parameter Not every Xsens device supports all functionality e g an MTi does not support getting a position estimate whereas the MTi G does This means that whether the function returns a meaningful result depends on the connected device The DevicelD indicates the MTi product with associated functionality a list of DevicelDs can be found in section 2 2 5 Exposing all the possible functionalities has the advantage that when changing the MTi in the application to a device with other functionalities the majority of the code can remain unchanged Internally the Xsens host software is implemented using an object oriented approach in which the functionality is only implemented in subclasses see schematic below OAOLIO nw Functions C API AOUOX 1 ACU0OY Devices Specific connected Xsens device Figure 2 Functionality implementation for specific products It is important for the developer to use only functions supported by the connected device During run time calling an unsupported function will generate an error status in line with the normal error handling framework C interface To offer the convenience of object lifetime management to developers the XDA is also offered as a C interface which basically implements a convenience
51. bed 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 Aq and Av Document MTO605P E Xsens Technologies B V 4 MTi User Manual 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 DevicelD The DevicelD 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 DevicelD The second digit of the DevicelD 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 100 series and the fourth digit denotes the interface e g 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 prod
52. ccelerations for time periods lasting longer than the maximum duration the MT s rate gyroscopes can reliably keep track of the orientation This will degrade the accuracy of the orientation estimates with XKF3i somewhat because the application does not match Document MTO605P E Xsens Technologies B V 16 MTi User Manual the assumptions made in the algorithm Note however that as soon as the movement again matches the assumptions made XKF3i will recover and stabilize The recovery to optimal accuracy can take some time NOTE To be able to accurately measure orientations as well as position in applications which can encounter long term accelerations we offer a solution that incorporates a GPS receiver the MTi G 700 GPS INS 3 2 2 Using the Earth magnetic field to stabilize yaw By default yaw is stabilized using the local earth magnetic field only in the MTi 30 AHRS In other words the measured magnetic field is used as a compass If the local Earth magnetic field is temporarily disturbed XKF3i will track this disturbance instead of incorrectly assuming there is no disturbance However in case of structural magnetic disturbance gt 10 to 30 s depending on the filter setting the computed heading will slowly converge to a solution using the new local magnetic north Note that the magnetic field has no direct effect on the inclination estimate In the special case the MTi is rigidly strapped to an object conta
53. ctor 799 In this example you could use the GPS pulse to synchronize the clock of the MTi with the GPS clock use Clock Bias Estimation but you also need to know the timing difference between the GPS and MTi So connect the 1 PPS to Trigger Indication as well the 1 PPS trigger will be inside the MT Data2 packet If you need orientation at a different rate than the camera images you can send the Interval Transition Measurement SyncOut at a SkipFactor and with an offset to give the camera time to make the picture Document MTO605P E Xsens Technologies B V 60 MTi User Manual 5 6 Internal clock accuracy 5 6 1 Clock of MTi s without GPS receiver The internal clock jitter of the MTi is less than 25ns The internal clock of the MTi which generates the sample timing based on the set sample period is accurate to 10 ppm with a maximum of 15 ppm this differs per MTi over the temperature operating range Using a typical MT with an accuracy of 10 ppm this means that the worst case deviation after a 1 hour log is 0 036 seconds 3600 s 10 ppm or 15 sample counts in 1 440 000 at 400 Hz sample rate 25 ns data packet 400 Hz 5 6 2 Clock of MTi G 700 GPS INS In the case that the MTi G has a GPS fix the bias of the clock will be estimated and on the long term there will on average be no deviation from GPS time On the short time scale the clock jitter is the determining factor The MTi G is capable of gene
54. d with the MT Manager The easiest way to get started with your MTi is to use the MT Manager software for Windows XP W7 This easy to use software with a Windows user interface allows you to record data and playback review data view orientation position and velocity in real time if available view inertial and magnetic sensor data in real time view low level communication and XDA communication via message terminals export log files to ASCII and KML KMZ change and view various device settings and properties reprocess pre recorded data e g with different settings The MT Manager is therefore an easy way to get to know and to demonstrate the capabilities of the MTi and to configure the device easily to suit your needs With the MT Manager it is possible to apply a configuration profile to multiple MTi s This allows system integrators to configure MTi s fast and accurate Applies to Windows PC platform Please refer to the MT Manager User Manual MTM for more information on this topic Document MT0605P E Xsens Technologies B V 11 MTi User Manual 2 6 3 Using the Software Development Kit SDK This chapter gives an introduction to the Xsens Device API XDA It serves as a starting point for members of a software development department interested in assessing the basis of the SDK and knowing about the background considerations The main objective of the SDK is to facilitate easy development of user sp
55. discard these transient accelerations they will have an effect after a certain period of time In the MTi 10 series this period is shorter than in the MTi 100 series The MTi G 700 with a good GPS fix can compensate for these long lasting accelerations Settling time Parameters in the MTi s such as the rate gyro bias or the pressure at sea level are continuously estimated The sensor fusion algorithms need some time to estimate such parameters Depending on the time since last calibration of the MTi s the chosen filter profile and the quality of the GPS fix this can take up to 15 minutes There is no need to have the MTi s static during the settling time on the contrary movement accelerations turns of the MTi s will help to estimate for example the gyro bias quicker as they become observable Good GPS fix MTi G 700 only o If there is no GPS fix the position estimates based on the IMU will degrade very rapidly in the order of a few seconds o If there is no GPS fix the MTi G cannot calculate correct attitude and heading under all dynamic conditions due to apparent gravity e g centripetal and linear Max error with respect to earth coordinate system 6 MTi 20 VRU and MTi 200 VRU unreferenced heading is yaw rate of gyroscopes Document MTO605P E Xsens Technologies B V 30 MTi User Manual be obtained e Barometric conditions 100 series only In some of the filter profiles the altitude of the MTi
56. e 0 8 us sample 100 Hz 5 7 Default Serial Connection Settings Setting Default Value Bits second bps 115200 Data bits 8 Parity none otop bits 2 Flow control none These settings are the same for the RS 232 as the RS 422 RS485 versions The baud rate bps setting can be changed by the user The maximum is 921600 bps and the minimum 4800 bps Please refer to the LLCP for details Should the communication fail it can be helpful to change the number of stop bits to 1 Note that there is no terminating resistor in the MTi with RS422 RS485 communication Should communication problems arise terminate the connection either at the application side or alternatively close to the MTi Document MT0605P E Xsens Technologies B V 61 MTi User Manual 5 7 1 General definitions for binary data All binary data communication is done in big endian format Example Un calibrated 16 bits accelerometer output 1275 decimal 0x04FB hexadecimal Transmission order of bytes 0x04 OxFB Calibrated accelerometer output float 4 bytes 9 81 decimal 0x411CF5C3 hexadecimal Transmission order of bytes 0x41 Ox1C OxF5 3 The bit order in a byte is always MSB LSB 2 bit 7 bit 0 5 7 2 Serial or USB communication The MTi has a parallel serial RS232 RS422 RS485 or alternative UART and USB interface However it is not possible to have communication on both the serial and USB interfaces sim
57. e tangent function NOTE that the output is in degrees and not radians 4 5 3 Rotation Matrix orientation output mode The rotation matrix also known as Direction Cosine Matrix DCM is a well known redundant and complete representation of orientation The rotation matrix can be interpreted as the unit vector components of the sensor coordinate system S expressed in L coordinate system For Ris the unit vectors of S are found in the columns of the matrix so col 1 is Xs expressed in L etc A rotation matrix 8 yaw is also known as heading pan or azimuth bitch is also known as elevation or tilt 10 roll is also known as bank Document MT0605P E Xsens Technologies B V 33 MTi User Manual norm is always equal to one 1 and a rotation Ais followed by the inverse rotation naturally yields the identity matrix 1 Risks The rotation matrix Ris can be interpreted terms of quaternions q qdi 42 4 24142 24093 24092 29193 Ris 29093 299 9 9 93 24293 28091 29193 24092 24293 280991 90 9 93 95 295 297 1 2419 2909 29193 29092 2919 2909 295 292 1 2493 24091 24193 24042 24243 29099 295 295 1 in terms of Euler angles Rgs cosy siny 0 s 0 0 0 siny cosy 0 coso sing 0 0 11 L sin COS sing cosqQ cos sin Y singsinOsinw coso cosy
58. ecific host applications based on Xsens motion trackers The MT SDK 4 x and the MT Software Suite are designed for the MTi 10 series and MTi 100 series The communication protocol is the same as in previous versions of the SDK Obviously new functionality has been introduced In some functions and messages a new term is introduced to point specifically to the MTi 10 series and MTi 100 series This term is MkIV or Mk4 in functions and is an abbreviation for Mark IV the 4 generation MTi 2 6 3 1 Using the Source code and Dynamic Library The MT SDK consists of Source code and a Dynamic Library Source code is made available in C since this language can be handled by many other programming languages such as C Java and Python Since C is a more convenient language to use for first time users of the MT SDK lower risk REMIS PES CS of making mistakes easier to handle complex i Host applications functions Xsens also supplies a C wrapper around the C compiled library Depicted on the COM C e right is a schematic overview of the MT SDK As Classes can be seen the host application developer can choose to use a COM C C or C interface However only the C interface is delivered as a Source code compiled dynamic library For the C and C Interface interface the source code of the wrapper classes libraries are supplied as part of the SDK The interfaces are Xsens discussed in more detail
59. eesevaueueeeeeavaueeeeeevaneueeeeeaveneess 65 6 3 1 Encased MTi connectors 65 6 3 2 OEM connections OVerVIeW epe peau 67 6 3 3 Additional interface specifications 69 6 3 4 Using the MkIV with an external USB 70 6 4 HOUSING MECHANICAL 6 4 1 X Environmental protection of the housing 1 GAZ Dmenons MT TTE 1 b43 Mou un ng e 1 6 44 10 series technical drawing 2 6 4 5 MTi 100 200 300 technical drawing 3 6 4 6 MTi G 700 technical drawing 4 6 4 7 technical drawing 5 7 IMPORTANT 2 tiii ip iu n acera Tw ada Gua arr Gu Tw Rn 76 7 1 SAFETY INSTRUCTIONS Jur ada sed dad bud 2 aas MuR dac 76 7 2 ABSOLUTE MAXIMUM RATINGS RENDER OR Rar RE CRM KONTEN a XR Ad E Een EU
60. eries Next to the better hardware the algorithm in the MTi 100 series is superior in detecting and coping with challenging conditions such as transient accelerations 2 5 2 Vibrations Although the MTi samples at 10kHz and includes a strap down integration algorithm with coning sculling compensation and vibration rejection for best results it is recommended that the MTi is mechanically isolated from vibrations as much as possible since vibrations are measured directly by the accelerometers the following two conditions can make the readings from the accelerometers invalid 1 The magnitude of the vibration is larger than the measurement range of the accelerometer This will cause the accelerometer to saturate which may be observed as a drift in the zero level of the accelerometer This will show up as an erroneous roll pitch 2 The frequency of the vibration is higher than the bandwidth of the accelerometer In theory such vibrations are rejected but in practice they can still give rise to aliasing especially if close to the bandwidth limit This can be observed as a low frequency oscillation Further high frequency vibrations often tend to have large acceleration amplitudes see item 1 There is an effect on the gyroscopes as well and especially when the vibrations include high frequent coning motion the gyroscope readings may become invalid The MTi 100 series features vibration rejecting gyroscopes designed to better cope with t
61. es The MTi 10 series and the MTi 100 series feature different gyroscopes and a different sensor fusion algorithm Therefore the high performance MTi 100 series require a more elaborate calibration method The individual calibration parameters are used to convert the sensor component readout digitized voltages to physical quantities as accurately as possible compensating for a wide range of deterministic errors Additionally the calibration values are used in both Xsens sensor fusion algorithms as discussed below 3 2 Xsens Kalman Filter for 10 series The orientation of the MTi 10 series is computed by Xsens Kalman Filter XKF3i uses signals of the rate gyroscopes accelerometers and magnetometers to compute a statistical optimal 3D orientation estimate of high accuracy with no drift for both static and dynamic movements XKF3 is a proven sensor fusion algorithm which can be found in various products from Xsens and partner products The design of the XKF3i algorithm can be summarized as a sensor fusion algorithm where the measurement of gravity by the 3D accelerometers and Earth magnetic north by the 3D magnetometers compensate for otherwise slowly but unlimited increasing drift errors from the integration of rate of turn data angular velocity from the rate gyros This type of drift compensation is often called attitude and heading referencing and such a system is referred to as an Attitude and Heading Reference
62. f the MTi are described The MTi s have tens of various output options it is possible to select a different output frequency and or output format e g float or double per output or group of outputs A full overview of outputs can be found section 4 1 Performance specifications on orientation position and sensor data can be found in section 4 3 Before going into these sections it is useful to read section 4 1 2 which explains the various coordinate systems and position representations Document MT0605P E Xsens Technologies B V 22 MTi User Manual 4 1 Overview of data outputs The MTi supports two different data protocols the binary hexadecimal XBus protocol and NMEA Refer to LLCP to learn how to switch between data protocols 4 1 1 MTData2 output in XBus protocol In order to learn more on how to work with XDA type name and Hex Value please refer to XDA DOC and LLCP respectively Temperature Timestamp Orientation Data Pressure Acceleration Temperature UTC Time Packet Counter Integer Time of Week GPS Age Pressure Age legacy Sample Time Fine Sample Time Coarse Frame Range Quaternion Rotation Matrix Euler Angles Baro Pressure Delta V Acceleration Free Acceleration Trigger Indication Position Triggerln1 Triggerln1 Altitude MSL Altitude Ellipsoid Position ECEF XDI TemperatureGroup XDI Temperature XDI TimestampGroup XDI UtcTime Packet
63. grammers familiar with using the CMT interface from the MT SDK 3 x and lower Xsens interface for legacy MTi products will find that changes need to be made in order to work with the new XDA Notable differences are shown below MT SDK 3 3 CMT 3 3 Xsens CMT Communication for Motion Trackers library Mixed C C interface Preallocation of buffers is often required Library functions are plain functions using an instance number and DevicelD for device identification Only supports MT9 C and Xbus Master devices Data output in fixed rate all in one format All functions are prefixed with cmt All structs are prefixed with Cmt source code is available including logging and custom functions Linux functions in source code only MT SDK 4 XDA 4 x XDA Xsens Device API library Pure C interface with C wrapper interface The C interface supplies the same functionality as the C interface but uses the class name as a function prefix ie XsControl openPort instead of XsControl openPort XDA managed safe interface objects are passed between the library and the application Library functions and structures are available as C classes without the need for explicit identification per function Supports all Xsens devices Data output rates configurable per type of output Also many more output types are available All global functions and objects are prefixed with Xs Source code is limited to a message interface Howe
64. hat refer to changeable settings For example the MID of message requesting the output mode ReqOutputMode is the same as the message that sets the output mode SetOutputMode The difference between the two messages is that the Length field of ReqOutputMode is zero and non zero for SetOutputMode Example Hequest current output mode Sending message ReqBaudrate OxFA OxFF 0x18 0x00 OxE9 hexadecimal values Receiving message Acknowledge ReqBaudrateAck OxFA OxFF 0x19 0x01 BR CS hexadecimal values ReqBaudrateAck contains data which represents the current mode BR CS stands for the checksum value To change the baud rate you must add the baud rate in the data field of the sending message Set the output mode Sending message SetBaudrate OxFA OxFF 0x18 0x01 BR CS hexadecimal values Receiving message Acknowledge SetBaudrateAck OxFA OxFF 0x19 0x00 OxE8 hexadecimal values Document MTO605P E Xsens Technologies B V 52 MTi User Manual 5 3 3 Common messages GoToConfig MID 48 0x30 Data field n a Direction To MTi Valid in Measurement State amp Config State Switches the active state of the device from Measurement State to Config State This message can also be used in Config State to confirm that Config State is currently the active state SetOutputConfiguration MID 192 DATA OutputConfig N 4 bytes Valid in Config State Set the output configuration of the device
65. he MTi to start processing data so that the start time for sampling can be chosen This is useful when the timing of a data needs to be aligned with an external sensor or sensor system at an accuracy of better than 2 5 ms Timing specification is as following 0 69 0 05 ms 3 19 0 05 ms 10 69 0 05 ms External pulse First sample 10kHz received First inertial data available First orientation received at MTi for signal processing acc gyr 400 Hz available 400 Hz It is possible to delay the First sample received and with that the entire data output with up to 0 65536 seconds For example setting a delay of 6810 us 6 81 ms will output data at exactly 10 ms after the external pulse has been received Document MTO605P E Xsens Technologies B V 99 MTi User Manual 5 5 6 Combining synchronization functions It is possible to configure multiple synchronization functions on the MTi This can be useful if you need to synchronize multiple devices e g a GPS device providing a 1 pulse per second PPS pulse an MTi 300 and an external camera that needs 0 2 seconds to make a picture 1 PPS to Clock X x RTK Position Bias Estimation 20 Hz 1 PPS to Trigger Indication GPS Time synced orientation and SDI data 50 Hz and marker Trigger Indication 1 Hz Interval Transition Measurement GPS time synced SyncOut base frequency 400 Hz Camera images Offset 0 2 sec Skipfa
66. hese specific conditions Note that the sleeve on the Fischer connector can move by design in order to enable unmating Vibrations on the MTi especially in the direction of the MTi s x axis can make the sleeve vibrate against the panel part of the connector This may be visible in the accelerometer and gyroscope data To prevent this the sleeve of the Fischer connector may be locked with the ring at the connector Xsens has tested a set of vibration dampeners on the MTi Vibration dampeners are low profile rubber cylinders that allow the MTi to be mounted on an object without a direct metal to metal connection that transduces vibrations from the object to the MTi The vibration dampeners have been tested with frequencies up to 1200 Hz that caused aliasing when the MTi was mounted directly on the vibration table had no effect with the vibration dampeners fitted The dampeners tested are manufactured by Norelem and have part number 26102 00800855 www norelem com Document MT0605P E Xsens Technologies B V 8 MTi User Manual 2 5 3 Magnetic materials and magnets When an MTi is placed close to or on an object that is either magnetic or contains ferromagnetic materials the measured magnetic field is distorted warped and causes an error in measured yaw The earth magnetic field is altered by ferromagnetic materials permanent magnets or very strong currents several amperes In practice the distance to the object and the amoun
67. his coordinate system is known as ENU and is the standard in inertial navigation for aviation and geodetic applications Note that it is possible to change the coordinate system using an alignment matrix or orientation reset The SD orientation output is defined as the orientation between the body fixed co ordinate system S and the earth fixed co ordinate system L using the earth fixed co ordinate system L as the reference co ordinate system Interpretation of yaw as heading Heading is defined as the angle between north and horizontal projection of the vehicle roll axis Yaw is defined for a particular local level navigation frame as the angle from a horizontal navigation axis to the projection of the longitudinal axis in the horizontal plane following the right hand rule Based on the definition of heading and yaw consider the use of the MTi in an aircraft which is stationary and pointing north Below a table is displayed that shows the heading and yaw outputs for the three reference coordinate system available with MTi Reference coordinate Direction of mounting Heading value not Yaw value system aircraft pointing North outputted by MTi East North Up ENU x axis of MTi aligned with 0 deg 90 deg vehicle pointing North North West Up NWU x axis of MTi aligned with 0 deg 0 deg vehicle pointing North North East Down x axis of MTi aligned with 0 deg 0 deg NED vehicle pointing North When using the ENU convention
68. igid body by means of three successive rotations in a particular sequence The Euler angles used are roll pitch yaw referred to in the literature as Cardan Tait Bryan angles The sequence of rotations for Euler angles follows the aerospace convention Z Y X sequence for rotation from the global reference co ordinate system L to the sensor co ordinate system S QU yaw rotation around Zi defined from 180 180 pitch rotation around Y which is the current Y axis after the first rotation defined from 90 90 Q roll rotation around Xi which is the current X axis after the second rotation defined from 180 180 NOTE Due to the definition of Euler angles there is a mathematical singularity when the sensor fixed X axis is pointing up or down in the L co ordinate system i e pitch approaches 90 This singularity is not present in the quaternion or direction cosine matrix rotation matrix representation Quaternion and rotation matrix output modes can be used to access these orientation representations respectively The Euler angles can be interpreted in terms of the components of the rotation matrix Ris or in terms of the unit quaternion 95 _ R32 29293 29091 tan tan Ls R33 24043 1 Ors sin 204q3 2909 R 2 2 TEE _ tan 2 ea 24044 1 Here the arctangent is the four quadrant invers
69. ining ferromagnetic materials structural magnetic disturbances will be present Using a so called magnetic field mapping MFM i e a 3D calibration for soft and hard iron effects these magnetic disturbances can be completely calibrated for allowing the MTi to be used as if it would not be secured to an object containing ferromagnetic materials 3 2 3 Initialization The XKF3i algorithm not only computes orientation but also keeps track of variables such as sensor biases or properties of the local magnetic field magnetic field MTi 30 AHRS only For this reason the orientation output may need some time to stabilize once the MTi is put into measurement mode Time to obtain optimal stable output depends on a number of factors An important factor determining stabilizing time is determined by the time to correct for small errors on the bias of the rate gyroscopes The bias of the rate gyroscope may slowly change due to different effect such as temperature change or exposure to impact 3 2 4 XKF3i filter profiles As described above XKF3i uses assumptions about the acceleration and the magnetic field to obtain orientation Because the characteristics of the acceleration or magnetic field differ for different applications XKF3i makes use of filter profiles to be able to use the correct assumptions given the application This way XKF3i can be optimized for different types of movement For optimal performance in a given application the correc
70. is the orientation of the sensor fixed co ordinate system S Condition Specification Horizontal Vertical Horizontal Vertical Q 30 m s Q 30 m s 1 0 m STD 2 0 m STD 2 0 m CEP 5 0 m CEP 0 1 m s 16 RMS 0 1 m s 16 RMS with respect to a Cartesian earth fixed co ordinate system L The output orientation can be presented in different parameterizations e Unit Quaternions Document MTO605P E O Xsens Technologies B V 31 MTi User Manual e Euler angles roll pitch yaw XYZ Earth fixed type also known as Cardan or aerospace sequence e Rotation Matrix directional cosine matrix A positive rotation is always right handed i e defined according to the right hand rule corkscrew rule This means a positive rotation is defined as clockwise in the direction of the axis of rotation NOTE This section is intended to give detailed information on the definition of the various orientation output modes of the MTi The output sequence of the elements in the vectors and matrices defined here holds for all interface options Low level communication protocol API GUI For more detailed information about the respective interfaces please refer to their specific documentation Low level communication gt MTi Low level Communication Documentation GUI gt MT Manager User Manual 4 5 1 Quaternion orientation output mode A unit quaternion vector can be interpreted to represents a rotation about
71. ld data all will have orthogonal xyz readings within 0 05 as defined in the figure above It is possible to rotate the sensor coordinate system to an object coordinate system when the MTi is not exactly aligned with the axes of the object or vehicle the MTi is attached to When this alignment matrix has been applied calibrated inertial data and magnetic field data are outputted in O See section 4 11 for more information on alignment matrices 4 2 2 Delta angle and delta velocity The SDI output of the MTi contain delta angle dq DatalD 0x8030 and delta velocity dv DatalD 0x4010 These values represent the orientation change and velocity change during a certain interval In the MTi this interval is 2 5 ms 400 Hz by default The values dq and dv are always represented in the same coordinate system as calibrated inertial data and magnetic field data see section 4 2 1 which can be S or O Document MT0605P E Xsens Technologies B V 25 MTi User Manual 4 2 3 Orientation data The MTi calculates the orientation DatalD 0x2010 0x2020 0x2030 between the calibrated inertial data and magnetic field represented in S or O and the local Earth fixed coordinate system L By default the local earth fixed reference co ordinate system used is defined as a right handed Cartesian co ordinate system with e X positive to the East E e Y positive to the North N e Z positive when pointing up U T
72. let the MTi switch to USB immediately When for some reason the MTi becomes unresponsive in serial mode and unplugging connecting the MTi does not solve the communication problem just connect the MTi to a USB port and check the settings of the device For RS422 devices there is a restore communication procedure see not available for alternative UART Alternative UART With the MTi OEM the alternative UART is available This UART interface is a direct serial interface with 3V3 CMOS levels It can be used e g on embedded systems To configure the MTi to communicate via this alternative UART use the command SetExtOutputMode see LLCP This setting will be stored in the non volatile memory so the device will start up communicating over this alternative UART unless a USB connection is detected Note that the maximum baud rate on the alternative UART is 750 kbps 6 3 2 2 GPS receiver The MTi G 700 GPS INS needs an active antenna The connection on the OEM board of the MTi G 700 is done with a u FL miniature coax 6 3 2 3 Connecting with the OEM board Connecting to the OEM board is possible by using sockets with a pitch of 1 27 mm Notable manufacturers are Samtec Molex and Hirose Two examples of such sockets are Socket Manufacturer Part number Farnell part number 10 pins 1 27 mm pitch Samtec FFSD 05 01 N 1753841 14 pins 1 27 mm pitch Molex 90635 1143 1392991 These connectors can be connected to ribbon cables withou
73. lid UTC When outputted the Time UTC starts as following At 0 0 sec unless Atime is available in the non volatile memory unless GPS time is available MTi G 700 only When the time stamp wraps over 0 00h midnight the date progresses a day 4 12 3 Time stamp Sample Time Fine The time stamp is a 0 1 ms resolution 4 byte time stamp 4 12 4 Setting UTC time on non GPS MTi s It is possible to set a time in UTC format to an MTi The MTi will count from this time using the internal clock As the moment of setting the time is different than the time the MTi receives the message and sets the starting point a message is implemented to adjust Time UTC in ticks of 0 1 ms See LLCP for more information about the messages SetUTCTime and AdjustUTCTime Document MT0605P E Xsens Technologies B V 47 MTi User Manual 4 13 Status byte The status byte includes information about the status of the MTi its sensors the filter and user inputs The following information can be found in the status byte and status word Status byte DatalD 0xE010 is the short status byte 8 bits identical to the status byte of the legacy output message see section 4 10 Status word DatalD 0xE020 is an extended 32 bits status message The bits in StatusWord are defined in the following table note that bit 0 7 are the same as Status Byte Bits Field Description 0 oelftest This flag indicates if the MT passed the latest self te
74. n out of range magnetic field on the X axis is detected 15 Clipflag Mag Y If set an out of range magnetic field on the Y axis is detected 16 Clipflag Mag Z If set an out of range magnetic field on the Z axis is detected 17 18 NoVelocityUpdate status Document MT0605P E Xsens Technologies B V 48 MTi User Manual 19 Clipping indication This flag indicates going out of range of one of the sensors is set when one or more bits from 8 16 are set 20 Reserved Reserved for future use 21 Syncin Marker When a Syncln is detected this bit will rise to 1 22 SyncOut Marker When SyncOut is active this bit will rise to 1 23 25 Filter mode Indicates the filter mode only available for MTi G 700 000 Without GPS filter profile is in VRU mode except GeneralMag filter profile that continues to use magnetometers 001 Coasting mode GPS has been lost 60 sec ago 011 With GPS default mode of MTi G 700 26 31 Reserved Heserved for future use Document MT0605P E Xsens Technologies B V 49 MTi User Manual 5 Basic communication 5 1 Introduction This section describes the basics of how to communicate with the MTi directly on low level using RS 232 422 485 serial communication or USB For a detailed and complete list of all messages please refer to the MT Low level Communication Documentation You can skip this chapter if you plan to only interface with the device using Xsens MT Manager GUI software
75. nd 5 z axis is the vertical up along gravity e the L and S x axis equals the S x axis but projected on the horizontal plane the L and S y axis is chosen as to obtain a right handed coordinate frame The coordinate rotation matrices R and SSR are calculated by 1 2 SS p 15 Rn 100 7 Z 00 1 Ko Document MT0605P E Xsens Technologies B V 44 MTi User Manual After an inclination and or heading reset the equation for SR is applied see above It should be noted that the inclination reset 55 R will not work if the sensor x axis is aligned along the z axis of the object since the sensor x axis is used to describe the direction of the object x axis Furthermore after a heading reset the yaw may not be exactly zero especially when the x axis is close to the vertical This is caused by the definition of yaw in Euler angles which becomes unstable when the pitch approaches 90 deg On y a b C d Figure 10 Top view and side view of an MT with coordinate frame S left strapped to an object and local frame L The different alignments and resets define the S and or L frame a the default orientation output of S with respect to L LSR b after inclination reset method 1 LS R c after heading reset method 2 L SR d after alignment reset method 3 L S R All of these are al
76. ng or hardware triggers For more Document MT0605P E Xsens Technologies B V 94 MTi User Manual information about triggering see section 5 5 Note that sampling of the sensors cannot be externally triggered because of the high sampling rate of 10 kHz It is possible to adjust the internal sampling clock though by using the ClockSync functionality see section 0 The time delay between a physical event e g an orientation change or acceleration is dictated by two factors 1 Internal acquisition calculation time and message generation signal processing duration 2 Serial transmission time Thanks to the system architecture of the Xsens sensor fusion algorithm the signal processing duration is independent of the filter profile Using a multi core processing unit it is possible to bring down the total time from physical event to data transmission on the USB or serial output to far below 2 ms The serial transmission time can easily be calculated when the byte message and the baud rate is Known total bytes message 10 bits byte Oo transmission time communication baudrate bits s These factors will be discussed using the example of two common output configurations of the MTi The bytes in the message consist of the Preamble BusID MessagelD length indicator data itself and the checksum The Preamble BusID MesssagelD length indicator and checksum together is always 5 by
77. ngitude Altitude in the WGS84 Ellipsoid The MTi G uses HE Height over Ellipsoid Altitude above Earth the ellipsoid WGS84 TT Furthermore the local gravity vector may differ from the h Geoid vector perpendicular to the local tangent plane perpendicular to the plane tangent to the ellipsoid as shown in the figure below The imaginary shape that is mem AUS Ellipsoid perpendicular to the natural gravity vector is called Figure 8 Difference between Geoid and geoid The value of vertical deviation or also called Ellipsoid vertical deflection can be a small fraction of a degree For the continental US the maximum vertical deviation can be about 0 01 degrees Document MT0605P E Xsens Technologies B V 29 MTi User Manual 4 3 Orientation performance specification In the MTi product portfolio several products provide roll pitch and un stabilized yaw The table below provides an overview of the specific products and orientation performances The 10 IMU and the 100 IMU are not listed as they do not provide orientation Typical orientation errors are in 16 RMS values maximum errors are in degrees Note that the validation tests can be found in the Technical Datasheet document MT0503P MTI For yaw maximum errors cannot be provided as this strongly depends on the environmental conditions MTi 20 MTi 30 MTi 200 MTi 300 MTi G 700 VRU AHRS VRU AHRS GPS INS Typ
78. 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 Aq and Av are available as all other processed data at 400 Hz 2 2 2 300 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 descri
79. ologies B V 7 MTi User Manual 6 46 MTi G 700 technical drawing 56 5 0 1 A 9 0 7 3x D I M MIN 2 5 3x SECTION A A SECTION B B SECTION C C CRITICAL DIMENSION 2 SURFACE TEXTURE VDI3400 12 SURFACE TEXTURE VDI3400 27 ALL FACES TEXTURED VDI3400 12 UNLESS OTHERWISE INDICATED NO SHARP EDGES ALLOWED 0 5 0 025 6X MIN 2 5 4x SECTION B B e m 3 5 0 05 2x 5 4x N ES C Pd Pais DETAIL SCALE 5 1 2 3 3 0 1 3X 0 1 3X SECTION A A 2x 4 0 05 4x SECTION D D C 3 CRITICAL DIMENSIONS ALL FACES TEXTURED VDI3400 12 NO SHARP EDGES ALLOWED Tolerances occ Moter iol 150 2768 ALUMINIUM 5060 Treatment Roughness acc ANODIZED RAL 7021 013400 12 CAD drawings STEP available at request via sales xsens com Document MTO605P E O Xsens Technologies B V 74 MTi User Manual 6 4 7 MTi OEM technical drawing Y boar U VU O gt lt CAD drawings STEP available at request via sales xsens com Document MTO605P E Xsens Technologies B V 19 MTi User Manual 7 important notices 7 1 Safety instructions e tis recommended to study the instructions below e not place the near strong magnetic fields Do not u
80. onfiguration and eMTS extended Motion Tracker Specification messages are always sent to the host Configuration data is the configuration that is read from the internal non volatile memory and will be used in the Measurement State The data in the Configuration message can always be used to determine the output mode and settings It is also possible to enter the Config State at power up see WakeUp message description in the MT Low Level Communication Document Another way to enter the Config State or Measurement State is to use the GoToConfig or GoToMeasurement messages The eMTS data is required to be able to later process the data by Xsens software to calculate calibrated inertial data values as well as estimating orientation etc The default configuration of the MTi is shown in the following table Property Value Output data and frequency Orientation quaternion legacy 2 100 Hz Sample Counter 2 100 Hz Baud rate 115k2 bps serial for USB not applicable Document MTO605P E Xsens Technologies B V 90 MTi User Manual 5 3 Messages 5 3 1 Message structure The communication with the MTi is done by messages which are built according to a standard structure The standard MT message can contain zero to 254 bytes of data and the total length is five to 259 bytes An MT message contains the following fields PRE BID MID LEN DATA CS Field Field width Descrip
81. or SDK API The communication protocol which is message based enables the user to change the configuration of the MTi and to retrieve the data from the device The communication protocol used for the MTi is mostly compatible with legacy MTi and MTx devices The configuration is fully user settable e g data output modes in amp output synchronization baud rate can all be changed to fit your requirements All configuration changes must be made while the device is in the so called Config State In this state the device accepts messages that set the output mode or changes to other settings Whenever the preferred configuration is completed the user can set the device to Measurement State In this state the device outputs data based the current configuration settings 5 2 States WakeUp procedure WakeUpAck No WakeUpAck received by device received by device GotoMeasurement Measurement GotoConfig The MTi has two states i e Config State and Measurement State In the Config State various settings can be read and written In the Measurement State the device will output its data message which contains data dependent on the current configuration There are two different ways to enter the Config State or the Measurement State At power up the device starts the WakeUp procedure if no action is taken it will then enter Measurement State by default using its latest stored configuration Prior to entering the Measurement State the C
82. or detection If all message bytes excluding the preamble are summed and the lower byte value of the result equals zero the message is valid and it may be processed The checksum value of the message should be included in the summation Document MT0605P E Xsens Technologies B V 91 MTi User Manual 5 3 2 Message usage Generally a message with a certain MID value will be replied with a message with a MID value that is increased by one i e the acknowledge message Depending on the type of message the acknowledge message has no or a certain number of data bytes In some cases an error message will be returned MID 66 0x42 This occurs in case the previous message has invalid parameters is not valid or could not be successfully executed An error message contains an error code in its data field Example Requesting the device ID of an MTi Sending message ReqDID OxFA OxFF 0x00 0x00 0x01 hexadecimal values Receiving message Acknowledge DeviceID OxFA OxFF 0x01 0x04 HH HL LH LL CS hexadecimal values The requested Device ID is given in the acknowledged message DevicelID here shown as HH HL LH LL the checksum is CS As you can see the MID Message ID of the acknowledgement is increased by one in comparison with the sending message ReqDID Some messages have the same MID and depending on whether or not the message contains the data field the meaning differs This is the case with all the messages t
83. r to section 6 3 for the pin configuration including 3V3 Document MT0605P E Xsens Technologies B V 64 MTi User Manual 6 3 Mechanical and electrical interface specifications 6 3 1 Encased MTi connectors overview The MTi is available as OEM version and encased version The encased version has an external 9 pins connection for power and data and one SMA connector for the antenna MTi G 700 only The colour of the hexagonal nut together with the colour of the base plate indicates whether the MTi is an MTi 10 series or MTi 100 series A grey silver base plate and nut indicates an MTi 10 series a dark grey black base plate and nut indicates an MTi 100 series 6 3 1 1 Power and data connection For connection with the Fischer receptacle Fischer part number DBPU 102 A059 130 Xsens supplies two cables The cable with product code CA USB MTi can be used to connect the MTi to any USB port except for MTi s with an RS422 interface The cable with product code CA MP MTi allows access to all 9 pins of the Fischer connector on the MTi 6 3 1 2 Pin configuration casing receptacle CA USB MTi Connect the cable to the MTi and the USB cable to any USB port Under Windows 7 and Windows XP the Xsens USB driver will be automatically installed if not already installed In order to lock the CA MP MTi to the casing this will prevent vibration of the push pull sleeve to be transferred to the casing and MEMS sensors screw the ro
84. rated 3D linear acceleration 3D rate of turn gyro and 3D magnetic field data is in sensor fixed coordinate system S or O The units of the calibrated data output are as follows Vector Unit Acceleration m s Angular velocity rate of turn rad s Magnetic field a u arbitrary units normalized to earth field strength Calibrated data has been going through Strapdown Integration and Inverse Strapdown Integration 4 9 4 Free acceleration Free acceleration Data ID 0x4030 is the acceleration of which gravity is deducted Output is in m s2 Document MT0605P E Xsens Technologies B V 41 MTi User Manual 4 9 5 Uncalibrated raw output mode The MTi can output sensor component readout SCR i e digitized voltages of all sensors before they are filtered or calibrated using Xsens proprietary firmware and calibration parameters These sensors are the gyroscopes rate of turn accelerometers acceleration magnetometer magnetic field barometer static pressure and temperatures gyroscope temperatures and a general temperature sensor When selecting sensor component readout the following outputs are available Sensor Digital analog Unit Maximum frequency Gyroscopes Analog sensor 16 bit ADC 2 byte integer 2000 Hz Accelerometers Analog sensor 16 bit 2 byte integer 2000 Hz Magnetometer Digital sensor a u 100 Hz Barometer Digital sensor Pa 50 Hz Temperature sensors Analog sensor 12 bit ADC
85. rating a quite accurate hardware synchronised time pulse when GPS is available The time pulse is synchronised to UTC time This accurate Time Pulse can be used to correct the sampling clock of the MTi G This clock bias estimation will improve the accuracy of the crystal used in the MTi G under normal operating conditions to below 1ppm The time pulse used to correct the clock of the MTi G has minor inaccuracies caused by the following e Delay caused by distance between antenna phase centre to input pin of the GPS receiver module in the MTi G The cable delay is 5 5ns m for PFTE resulting in 16 5ns delay with the development kit antenna PCTel 3910D e Quantisation loss clock of 23 104MHZz results in a resolution of 43ns e Rise time of Timepulse 7 25ns best results when loaded with a high impedance e Software delay for handling the time pulse interrupt clock ticks 300Mhz The first point is compensated in the MT GPS receiver but will vary with cable length The internal clock jitter of the MTi is less than 25ns The internal clock of the MTi which generates the sample timing based on the set sample period is accurate to 10 ppm with a maximum of 15 ppm this differs per MTi over the temperature operating range f there is no GPS fix available Using a typical MT with an accuracy of 80 ppm this means that the worst case deviation after a 1 hour log is 0 288 seconds 3600 5 80 ppm or 29 sample counts 360 000 at 100 Hz sample rat
86. ree 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 Aq and Av 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 Aq and Av Document MT0605P E Xsens Technologies B V 3 MTi User Manual 2 2 100 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
87. resented in various coordinate systems which are explained below 4 2 1 Calibrated inertial data and magnetic field data The sensor coordinate system S is a right handed coordinate Carthesian system that is body fixed to the device and is used to output rate of turn DatalD 0x8020 acceleration DatalD 0x4020 and magnetic field DatalD 0xC020 The encased version of the MTi shows the coordinate system on the sticker Depicted below is the sensor coordinate system on the encased MTi and the OEM version omall x y and z are used for S and the object coordinate system O Capital X Y and Z are generally but not always used for velocity They stand for the local earth fixed coordinate system L see section 4 2 3 Figure 3 coordinate system of the encased MTi Figure 4 Coordinate system of the MTi OEM Note origin is located at the accelerometers Note origin is located at the accelerometers The aluminum base plate of the MTi is carefully aligned with the output coordinate system during the individual factory calibration The alignment of the bottom plane and sides of the aluminum base plate with respect to the sensor fixed output coordinate system S is within 0 1 deg Convenient alignment points are designed in the base plate of the MTi The non orthogonality between the axes of the body fixed co ordinate system S is 0 05 This also means that the output of 3D linear acceleration 3D rate of turn gyro and 3D magnetic fie
88. s the calibration values determined during the calibration of the MTi at Xsens calibration facilities The values are explained here in short The IMU specifications chapter contains the full ranges and bandwidths of the physical sensors inside The Basic test results describes the noise of the all internal sensors and contains residuals in orientation Calibration data are the values that describe the conversion from the physical phenomenon to a digital output in an orthogonal coordinate system Gains bits Gains or scale factor describe the relation between the digital reading in bits and the measured physical signal Offsets bits Digital reading in bits of the sensor when no physical signal is measured Alignment matrix Non orthogonality of the sensor triade This includes non orthogonality in the orientation of the sensitive system inside the MEMS sensor the mounting of the sensors on the PCB of the MTi the mounting of the PCB s and the misalignment of the OEM board in the MTi housing Next to the basic Test and Calibration values documented in the certificate each device is calibrated according to more complicated models to ensure accuracy e g non linear temperature effect cross coupling between acceleration and angular rate 11 Also known as g sensitivity Document MTO605P E Xsens Technologies B V 39 MTi User Manual 49 Sensors data outputs 4 9 1 Physical sensor model This
89. se aa ne sese spese nnus 35 Z0 SAY OS CODES Emm nM I Jo 4 6 2 Accelerometers and magnetometer 36 253 JBHIODPPeF 36 37 4 7 BUILT IN SELF TEST 2 sccacceccecaecatceccecausaececcesausaececcusausanseeaesautaececausausaecesaesansaecasausansascasausansescasantates 38 4 8 TEST AND CALIBRATION CERTIFICATE ostenta napa ks aie Senko 39 49 SENSORS DATA OUTPUTS 40 4 9 1 Physical sensor 40 4 9 2 Calibrated delta and delta v 41 4 9 3 Calibrated inertial and magnetic data outputs 41 aoa FCC GOCE er ON 41 4 9 5 Uncalibrated raw output mode 1cccccccceceeceececceteeneeceesuneeseecuesenseseesensuneeseesersuteeseeeetseneeseees 42 4 10 LEGACY OUTPUT MESSAGES 43 4 11 RESET OF OUTPUT OR REFERENCE CO ORDINATE SYSTEMS esseeeeneen nennen nenne nnne saei nene nere se se 44 4 12 TIMESTAMP AND PACKET COUNTER OUT
90. se cables or connectors other than described in this manual 7 2 Absolute maximum ratings Stresses above Absolute Maximum Ratings may cause permanent damage to the device Shock any axis 20000 m s 2000 g 0 5 ms half sine Standard Input Voltage 0 3 V 40V Alternative Input Voltage 3 9 V 0 1 V Interface inputs 25 V 25 V RX A and B inputs 0 3 V 3 6 V alternative UART Syncin 0 20 V Bidirectional Syncin 0 3 6V Operating Storage Temperature 40 C 85 C Humidity Casing is IP67 for OEM 95 max non condensing Stresses beyond those listed here may cause permanent damage to the device These are stress ratings only and functional operation of the MTi at these or any other conditions beyond those indicated in section 4 6 of the specifications is not implied Exposure to absolute maximum rating conditions for extended periods may affect device reliability NOTE Drops onto hard surfaces can cause shocks of greater than 20000 m s 2000 g exceed the absolute maximum rating of the device Care should be taken when handling to avoid damage Drops causing shock greater than absolute maximum ratings may not destroy the device but will permanently alter the properties of the physical motion sensors which may cause the device to become inaccurate 7 3 Maintenance The MTi will not require any maintenance if properly used see also section 7 1 and 7 2 However if the Motion Tracker is not functioning according
91. se whether the Syncin signal needs to be triggered on rising edge or falling edge etc The internal clock determines when data is available This data is transmitted only if a trigger is detected on the Syncin line or when polled ReqData This means that the trigger instance will not coincide with the availability of the data Because two different clocks are used the time difference between the trigger instance and the last sampling instance may vary during the measurement and at most with a time equal to the used sampling period 5 5 2 Marker in MT data Trigger Indication Next to let the MTi send data to the computer it is also possible to incorporate a trigger indication in the MTData2 packet Status Word The data will not be affected by the trigger indication the data is marked with the pulse received Document MT0605P E Xsens Technologies B V of MTi User Manual 5 5 3 MTi triggers external devices Interval Transition Measurement In case the clock specification of the MTi is accurate enough for the measurement the MTi can provide a sync pulse which is generated based on its internal clock at a frequency of 400 Hz regardless of the frequency of the data outputted For more details on clock accuracy see section 5 6 For example when Interval Transition Measurement is set with a skip factor of 4 and a pulse width of 1000 us the following will be outputted 1 ms sync pulse 9 ms no sync pulse 1 ms sync pulse
92. section explains the basics of the individual calibration parameters of each MTi This explains the values found on the MT Test and Calibration Certificate that comes with each MTi The physical sensors inside the MTi accelerometers gyroscopes and magnetometers are all calibrated according to a physical model of the response of the sensors to various physical quantities e g temperature The barometer and GPS receiver do not require calibration The basic model is linear and according to the following relation 5 Kr u br The model really used is more complicated and is continuously being developed further From factory calibration each MTi has been assigned a unique gain matrix Kr and the bias vector br This calibration data is used to relate the sampled digital voltages u unsigned integers from the 16 bit ADC s from the sensors to the respective physical quantity s The gain matrix is split into a misalignment matrix A and a gain matrix G The misalignment specifies the direction of the sensitive axes with respect to the ribs of the sensor fixed coordinate system S housing E g the first accelerometer misalignment matrix element a1 x describes the sensitive direction of the accelerometer on channel one The three sensitive directions are used to form the misalignment matrix 04 x ayy 5 G4 0 0 A Q x Q5 G G gt 0 0 G4 0 0 1 x ayy 7 Ky 0 0 2z 0 0 0
93. so possible to set with arbitrary alignments NWU and NED reference coordinate frames The default reference coordinate frame in the MTi is ENU frame described in section 4 2 3 the MTi supports two other reference coordinate systems that can be selected These are NWU and NED NWU is the reference coordinate system that used to be the default up to the third generation MTi and MTi G In order to configure the MTi to output in the NWU local frame apply the following rotation matrix in RotLocal 0 1 O0 RotLocalyyy 1 0 0 0 0 1 Document MT0605P E Xsens Technologies B V 45 MTi User Manual NED is a reference coordinate system often used in aerospace applications NED is also a reference coordinate system available in the third generation MTi and MTi G In order to configure the MTi in NED apply the following rotation matrix in RotLocal 0 1 0 RotLocalygp 1 0 0 0 0 1 Arbitrary alignment If the measured kinematics is required in a frame S and or a frame L with known orientations with respect to standard sensor coordinate frames S and L the alignment matrices can be set with an arbitrary but known orientation This can be useful if for mechanical reasons the MT can only be fastened in some specific orientation The alignment matrices or 5 R are applied to the output data according to the equations above Refer to the MT Manager User Manual on how to use these alignment matrices The differen
94. ssage consists of multiple N packets Each packet starts with a two byte Data Identifier followed by a one byte Size field After that follows the Packet Data that is Size bytes long The Data Identifier determines the format of the Packet Data This packet scheme makes the output data format very flexible If a particular output data is not available the packet is omitted from the message Also if during parsing of the message an unknown Data Identifier is encountered the packet can be skipped using its Size field It allows for more optimal bandwidth usage and simplifies keeping future devices and or software backwards compatible In the MT Low Level Communication Protocol documentation format descriptions of all data packets are described 5 4 Communication Timing For many applications it can be crucial to know exactly the various delays and latencies in a system In this section it is described how the timing between physical events and the device output are related in the basic usage modes of the MTi Samplin Output formatting and Sensor fusion and ADC calibration message generation Hardware software triggers Triggering When the MTi is in Measurement State the internal processor core continuously controls a signal processing pipeline roughly according to the above diagram Outputting data can be triggered by the device internal clock or by external software triggers polli
95. st RunSelftest 1 Filter Valid This flag indicates if input into the filter orientation filter is reliable and or complete If for example the measurement range of internal sensors is exceeded orientation output cannot be reliably estimated and the filter flag will drop to 0 For the MTi G the filter flag will also become invalid if the GPS status remains invalid for an extended period 2 GPS fix This flag indicates if the GPS unit has a proper fix The flag is only available in MTi G units 3 4 NoRotationUpdate Status only available for legacy devices This flag indicates the status of the no rotation update procedure in the filter after the SetNoRotation message has been sent 11 Running with no rotation assumption 10 Error Rotation detected procedure not started sticky 01 Estimation complete some samples rejected sticky 00 Estimation complete no errors 5 Timestamp GPS synced 6 Timestamp clock synced 7 On Off 8 Clipflag Acc X If set an out of range acceleration on the X axis is detected 9 Clipflag Acc Y If set an out of range acceleration on the Y axis is detected 10 Clipflag Acc Z If set an out of range acceleration on the Z axis is detected 11 Clipflag Gyr X If set an out of range angular velocity on the X axis is detected 12 Clipflag Gyr Y If set an out of range angular velocity on the Y axis is detected 13 Clipflag Gyr Z If set an out of range angular velocity on the Z axis is detected 14 Clipflag Mag X If set a
96. t filter profile must be set by the user For information on how to specify a filter profile in XKF3i please refer to the MT Manager User manual MTM or the MT low level communication protocol documentation LLCP The different filter profiles are divided in several types of motion and are discussed below Number Name IMU Magnetometer Product 39 General 30 AHRS 40 High mag dep 30 AHRS 41 Dynamic 30 AHRS 42 Low mag dep 30 AHRS 43 VRU general 30 AHRS 20 VRU Document MT0605P E Xsens Technologies B V 17 MTi User Manual The general filter profile is the default setting It assumes moderate dynamics and a homogenous magnetic field External magnetic distortions are considered relatively short up to 20 seconds Typical applications include camera tracking e g TV camera s remotely operated robotic arms on ROV s etc The high mag dep filter profile assumes homogenous magnetic field and an excellent Magnetic Field Mapping This filter profile heavily relies on the magnetometer for heading Dynamics of the motion are relatively slow Typical applications are navigation of ROV s or the control of small unmanned helicopters The dynamic filter profile assumes jerky motions However the assumption is also made that there is no GPS available and or that the velocity is not very high In these conditions a 100 series MTi may be a better choice The dynamic filter profile uses the magnetometer for st
97. t of ferromagnetic material determines the amount of disturbance Errors in yaw MTi 30 MTi 300 and MTi G 700 only due to such distortions can become quite large since the earth magnetic field is very weak in comparison to the magnitude of many sources of distortion Whether or not an object is ferromagnetic should preferably be checked by using the MTi s magnetometers It can also be checked with a small magnet but be careful you can easily magnetize hard ferromagnetic materials causing even larger errors If you find that some object is magnetized hard iron effect this is often the case with for example stainless steels that are normally not magnetic it may be possible to degauss the object In most cases when the disturbance of the magnetic field caused by placement of the MTi on a ferromagnetic object can be corrected for using a specialized calibration procedure commonly known as a hard and soft iron calibration The calibration procedure MTi 30 MTi 300 and MTi G 700 only can be executed in a few minutes and yields a new set of calibration parameters that can be written to the MTi non volatile memory This calibration procedure is implemented in the software module Magnetic Field Mapper MFM that comes with the Software Suite Disturbance caused by objects in the environment near the MTi like file cabinets or vehicles that move independently with respect to the device cause a type of distortion that cannot be accounted for
98. t orientation resets can be summarized as follows Inclination reset Applying SSR only Heading reset Applying only Alignment reset Applying both R and 5 NOTE when applying SS R and outputting dq dv only will result in double applying of SS R when outputting orientation from XDA To prevent this output orientation directly from the MTi Document MTO605P E Xsens Technologies B V 46 MTi User Manual 4 12 Timestamp and packet counter output Each data message can be accompanied by a packet counter and or timestamp 4 12 1 Packet counter The packet counter is an incremental number that comes with each packet regardless of what data is in the packet It can also mean that time differences between packet counters may not be the same Note that the packet counter is a good indication if data is missed during transmission of the data as the packet counters are created when generating composing a data message prior to sending 4 12 2 Time UTC Time UTC is time in the format of UTC note that this time does not have to be synchronized with GPS UTC The format is described below DATA B Description Nanoseconds of second range O 1 000 000 000 Year range 1999 2099 Month range 1 12 Day of Month range 1 31 Hour of Day range 0 23 Minute of Hour range 0 59 O Oo Oo o 0 Seconds of Minute range 0 59 1 0x01 Valid Time of Week 0x02 Valid Week Number 0x04 Va
99. t tools to make a cable like below On the right is an application of such a cable Document MTO605P E Xsens Technologies B V 68 MTi User Manual 6 3 3 Additional interface specifications The MTi has three GPIO lines on the main 10 pins connector and thus on the 9 pins external Fischer connector These 3 lines can be configured individually for synchronization purposes see section 5 5 The three Sync lines are the following Low value 0 0 8 V Input resistance 100 0 20V High value 2 5 20 V SyncOut Low value 0 0 4 V Output load gt 330 Q N A High value gt 2 9 V ClockSync Low value 0 0 8 V Input resistance 100 0 20V High value 2 5 20 V For the descriptions of the synchronization functions see LL CP Document MT0605P E Xsens Technologies B V 69 MTi User Manual xSens 6 3 4 Using the MTi MkIV with an external USB converter Xsens offers cable to use the MTi with USB and Syncln This cable also offers an interface via a virtual COM port instead of WinUSB The following cables are available in Xsens webshop http shop xsens com CA USB2 MTI Multi use cable for MTi MkIV RS232 CA USB4 MTI Multi use cable for MTi MkIV RS485 CA USB6 MTI Multi use cable for MTi MkIV RS422 It is possible to connect the MTi MkIV to legacy USB converter cables Follow these instructions disassemble a legacy CA USB2 CA USBA or CA U
100. tes The length of the various data messages is discussed in LLCP Example 1 Euler angels orientation data at 400 Hz and SDI data delta q and delta v at 100 Hz with a baud rate of 230400 bps RS232 Euler angles is 12 bytes SDI data is 24 bytes This means that there will be one message of 41 bytes followed by three messages of 17 bytes and then one message of 41 bytes again omar 36 5 10 bits byte T ransmission time Euler angles an 230400 bits s 1 78 ms 12 5 10 bits byte ransmission time only 230400 bits s 0 74ms Note that although the average data stream is lower than the baud rate it is not possible to choose a baud rate lower than 230400 bps in this particular case as data comes at 400 Hz every 2 5 ms and the longest transmission time at a baud rate of 115200 bps would be 3 56 ms Example 2 Quaternion data output at 100 Hz with a baud rate of 921600 bps RS232 Quaternion data is 16 bytes b 0 23 Xsens Technologies B V 55 MTi User Manual USB communication timing When the MTi is used with the USB cable much of the timing depends on the scheduling of the host e g Windows as the host needs to poll data from the USB devices For real time interfaces a serial interface RS232 RS422 or RS485 is recommended Document MTO605P E MTi User Manual Xsens Technologies B V 56 5 5 Triggering
101. that is suitable for the MTi G 700 Please consult www xsens com support Document MTO605P E O Xsens Technologies B V 37 MTi User Manual 47 Built in self test All MTi s feature a built in self test BIT The self test actuates the mechanical structures in the MEMS accelerometer and gyroscope by inducing an electric signal This allows checking the proper functioning of the mechanical structures in the MEMS inertial sensors as well as the signal processing circuitry In the magnetometer a magnetic field is induced by a coil designed around the component which will generate an offset in the signal During self test the MTi will read out all sensors and in case of a successful self test a known offset with respect to the signal prior to enabling self test should be visible in the data The MTi will internally evaluate the sensors readings the self test will return the status of the self test per individual sensor The status is stored into the non volatile memory A passed self test will result in a valid self test flag in the status byte Because the self test influences the sensor data the self test is only available in Config mode For more information refer to LLCP function RunSelftest Document MTO605P E Xsens Technologies B V 38 MTi User Manual 4 8 Test and Calibration Certificate Each MTi is accompanied by an individual Test and Calibration Certificate This certificate state
102. tion PRE 1 byte Preamble indicator of start of packet gt 250 OxFA BID 1 byte Bus identifier address gt 255 OxFF MID 1 byte Message identifier LEN 1 byte Value equals number of bytes in DATA field Maximum value is 254 OxFE Value 255 OxFF is reserved DATA 0 254 bytes Data bytes optional CS 1 byte Checksum of message Preamble PRE Every message starts with the preamble This field always contains the value 250 Bus identifier BID or Address All messages used for the MTi and MTx use the address value 255 OxFF indicating a master device MT s used on the Xbus have other BID s Message Identifier MID This message field identifies the kind of message For a complete listing of all possible messages see MTi and MTx Low Level Communication Document The message MT Data2 is explained in section 5 3 3 Length LEN Specifies the number of data bytes in the DATA field Value 255 is reserved This means that a message has a maximum payload of 254 bytes If Length is zero no data field exists Data DATA This field contains the data bytes and it has a variable length which is specified in the Length field The interpretation of the data bytes are message specific i e depending on the MID value the meaning of the data bytes is different See the description of the specific message for more details about interpretation of the data bytes Checksum This field is used for communication err
103. ucts and interfaced with their corresponding products 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 u G 700 Document MT0605P E Xsens Technologies B V 5 MTi User Manual 2 3 Evolution of MTi products The MTi 10 series and MTi 100 series are Xsens 4 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 Introduced AHRS comparable in function to the 2005 MTi 30 and MTi 300 It has a plastic Available at casing and aluminum bottom plate least till Dec am Product codes are in the form of MTi 2013 28
104. uld they need to take these into account This section is primarily in the User Manual for completeness and accuracy reasons World coordinates WGS84 and LTP Navigating around the world f using GPS and inertial sensors requires an understanding of the Cartesian and Spherical coordinate systems commonly used for describing a position on the Earth For purposes of measuring and determining the orbits of the GPS satellites it is convenient to use an Earth Centered Inertial ECI coordinate system in which the origin is at the centre of the mass of the Earth and which axes are pointing in fixed direction with respect to the stars For the purpose of computing the position of a GPS receiver it is more convenient to use a coordinate system that rotates with the Earth known as an Earth Centered Earth Fixed ECEF system In the ECEF system the xy plane coincides with the Earth s equatorial plane the x axis points in the direction of 0 longitude Greenwich meridian and the y axis points in the direction of 90 E It is typical to transform these Cartesian coordinates to latitude longitude and height or altitude which are often projected on maps In order to carry out this transformation it is necessary to have a physical model Document MT0605P E Xsens Technologies B V 27 MTi User Manual describing the Earth The standard physical model of the Earth used for GPS applications is the World Geodetic System 1984 WGS84
105. ultaneously Therefore the MTi wakes up as a serial device unless USB is detected When a USB interface is detected the communication will be done via that USB interface Document MTO605P E Xsens Technologies B V 62 MTi User Manual 6 Physical Specifications 6 1 Physical properties overview All products of the MTi product range have the same mechanical and communication interfaces Note that the RS422 version does not have an on board USB interface MTi 10 series MTi 100 series MT i A G H 1 MTi G 700 A G 2 RS232 USB UART OEM only 4 RS485 USB UART OEM only 6 RS422 UART OEM only no USB 3x SyncOut Syncln GPIO Communication interface Additional interfaces Operating voltage 4 5 30V Power consumption 530 mW 5V 650 mW 5V 960 mW 5V Temperature operating 40 C 85 C range Specified performance 0 C 55 C operating range Altitude operating range N A N A 900 m 9000 m baro lt 18000 m GPS Maximum velocity N A N A 0 515 m s Outline dimensions 57 x 42 x 24 mm 57 x 42 x 24 mm 57 x 42 x 24 mm W x L x H W x L x H W x L x H Weight 55g cased 55g cased 58g cased 11g OEM 11g OEM 11g OEM 6 2 Power supply The nominal power supply of the MTi is 5V DC The minimum operating supply voltage is gt 4 5V for the external connector and the absolute maximum is 40V e The sensor works at a power supply of gt 4 5
106. und nut clockwise Be sure not to tighten too fast To unplug the CA MP MTi screw the round locking counter clock wise and pull the connector out of the receptacle by sliding the sleeve of the connector backwards 2 90 i Fisher SV 102 A 059 1 30 E Jr GND 4 D 3 D 2 VCC 1 Solder bucket view back side Functionality Wire colour Fisher pin no USB pin no 10 pins OEM header GND Black 1 4 4 8 NC 2 NC 3 Vin Red 4 1 1 NC 5 NC 6 NC 7 USB DP D Green 8 USB DM D White 9 Document MT0605P E Xsens Technologies B V 65 MTi User Manual CA MP MTi Cable CA MP MTi allows for full control of the MTi Hardware synchronization options are available as well as easy access to the serial interface Although the USB connection wires of the CA MP MTi are connected it is not recommended to use the USB connection as the shielding of the CA MP MTi cable is not attached to the Molex header In order to lock the CA MP MTi to the casing this will prevent vibration of the push pull sleeve to be transferred to the casing and MEMS sensors screw the round nut clockwise Be sure not to tighten too fast To unplug the CA MP MTi screw the round locking counter clock wise and pull the connector out of the receptacle by sliding the sleeve of the connector backwards O Fisher SV 102 A 059 130 2 Molex Solder bucket view back side PicoBlad Functionality Wire color
107. ut will then be offset by the declination calculated internally and thus referenced to local True North The MTi G 700 GPS INS calculates True North automatically when GPS position is available 4 2 4 Velocity data Velocity data calculated by sensor fusion algorithm DatalD OxDO1 0 is outputted in the same coordinate system as the orientation data and thus adopts orientation resets as well It is available only in the MTi G 700 Velocity data from the navigation solution from the GPS receiver DatalD 0x8840 is represented in Earth Centered Earth Fixed ECEF 4 2 5 Position data Position data calculated by the sensor fusion algorithm DatalD 0x5040 is represented in Latitude Longitude in the WGS84 datum It is available only in the MTi G 700 It is possible to retrieve position data calculated by sensor fusion algorithm in Earth Centered Earth Fixed ECEF format Use DatalD 0x5030 to retrieve this output Altitude is outputted in WGS84 datum DatalD 0x5020 Position data from the navigation solution from the GPS receiver DatalD 0x8840 is represented in Earth Centered Earth Fixed ECEF 4 2 5 4 Linearization errors and relation WGS84 and LTP The following section describes in more detail the linearization errors made and other artefacts introduced when using global coordinate systems It also describes the relation between WGS84 LLA and ENU LTP Most users will not experience these artefacts neither sho
108. utages recur regularly or if you have bad GPS availability e g in urban canyons consider using AutomotiveUrbanCanyon In the Automotive filter profile yaw is locked e g gyro bias will be estimated and yaw will not change when GPS indicates that there is no movement This is useful when standing still as gyro bias would otherwise induce a yaw drift Document MT0605P E Xsens Technologies B V 20 MTi User Manual The AutomotiveUrbanCanyon filter profile is similar to the Automotive filter profile in that they both use the same assumptions The assumptions are triggered with the monitoring on the GPS receiver measurements The filter profile assumes the deteriorated GPS conditions and places less trust on holonomic constraint updates The user is advised to make use of this filter profile for robust performance in deteriorated GPS conditions Using the Automotive filter profile instead of AutomotiveUrbanCanyon in applications where GPS conditions are deteriorated can result in long position outages Every application is different and although example applications are listed above results may vary from setup to setup It is recommended to reprocess recorded data with different filter profiles in MT Manager to determine the best results in your specific application Document MT0605P E Xsens Technologies B V 21 MTi User Manual 4 Output Specification In this chapter the various output modes o
109. ver fewer messages are required to configure MTis and data messages are easier to understand so the message interface is more robust A shared object for Linux on x86 processors is available beta XDA can be run side by side with CMT but the libraries don t interact A full conversion to XDA is recommended The following coding steps are needed replace all Cmt objects in the code by their Xs counterparts and replace DevicelD storage by XsDevice storage and use XsDevice class functions instead of global CMT functions In section 2 6 3 1 the typical workflow of XDA is explained Also refer to examples to be found in the Xsens folder in Program Files of your computer Document MTO605P E O Xsens Technologies B V 14 MTi User Manual MTi 10 series and MTi 100 series devices are designed to drop in replaceable with legacy MTi and MTx devices When new MTi s are configured to output orientation data in legacy output mode CMT will recognize the device In this case only basic functionality is available such as the reading of orientation data See section 4 10 for more information about the legacy output mode 2 6 6 Terms of use MT Software Suite The installer of the MT Software Suite can install 4 components of the MT Software Suite the MT Manager the MT SDK the MT Magnetic Field Mapper and the MT Firmware Updater It is possible to install only parts of the MT Software Suite so every component has a separate EU
110. w data 16 bit binary data with legacy source code into orientation position or dynamic data 3 4 generation All outputs are only available at frequencies that can be are integer divisions of 400 Hz 400 Hz 200 Hz 100 Hz 80 Hz etc The following outputs are available in the MTi legacy data message Available legacy output modes Orientation Quaternions NWU Euler angles NWU Rotation Matrix NWU Calibrated data Rate of turn Acceleration Magnetic Field Note that at a frequency higher than 100 Hz magnetometer data will be sent out duplicate 200 Hz will result in two duplicate values 400 Hz will result in 4 duplicate values Timestamp Sample counter 16 bits wraps after 65536 samples UTC MTi G 700 only Position and velocity 3D Position LLA 3D Velocity ENU Status Status byte Self test valid XKF GPS fix MTi G 700 NoRotation status Document MTO605P E Xsens Technologies B V 43 MTi User Manual 4 11 Reset of output or reference co ordinate systems In some situations it may occur that the MT sensor axes are not exactly aligned with the axes of the object of which the orientation has to be recorded It may be desired to output the orientation and or calibrated inertial data in different sensor fixed frame S instead of S or a different earth fixed local frame L instead of L The transformations are defined by the rotation matrices R and SSR resulting in the following equations affecting
111. wrapper around the C API This means that the developer does not have to deal with memory management i e easy object lifetime management as the class implementation takes care of this This means that for example functions named XsDevice function name in the C interface are available in the C interface as the function name method of the XsDevice class COM interface For MS Windows environments all the functionality is also available via a COM interface Document MT0605P E Xsens Technologies B V 13 MTi User Manual 2 6 4 Direct low level communication with MTi The MTi features a powerful embedded multi processor core Since the MTi has an on board non volatile memory that can store all settings the MTi can conveniently be used without using a host computer The low level communication protocol named XBus protocol offers full control and functionality however without the convenience advantages that the Xsens Device API offers such as threading object oriented programming and error handling Low level communication is essential on platforms that do not support the Xsens Device API such as custom embedded computers The low level communication is extensively described in the Low Level Communication Protocol Documentation Next to that source code is delivered to make driver development and Xbus message parsing for the MTi as easy and quick as possible 2 6 5 Migration from MT SDK 3 3 CMT Pro
112. y similar to the general filter profile However it does not use the barometer for height estimation it thus uses GPS and accelerometers only Since airflows near the venting holes in the MTi G will lower the barometric pressure and thus make height estimations inaccurate you can use this filter profile when the MTi G is mounted in such airflow The GeneralMag filter profile bases it yaw mainly on magnetic heading together with comparison of GPS acceleration and the accelerometers Although this combination makes the yaw more robust than magnetic field alone a homogenous or calibrated for magnetic field is essential for good performance yaw Other parameters are tuned the same as in the General filter profile The Automotive filter profile assumes that the yaw of the MTi G is also the GPS course over ground holonomic constraints This assumption holds for most automotive ground vehicles except for those who experience side slip such as racing cars tracked vehicles some articulated vehicles depending on where the MTi G is mounted and vehicles driving on rough terrain The Automotive filter profile thus uses GPS to determine the yaw Note that it is essential to mount MTi G exactly in the direction of movement in order to prevent an offset Please refer to 4 2 3 for proper mounting When GPS is lost yaw will be determined by the velocity estimation algorithm for 60 seconds before yaw is determined by gyroscopes integration only Should GPS o

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