Document MVN Manual, Revision Z, 01 04 2021 MVN User Manual
Revision Z Date 01 04 2021 By PHA Changes MVN 2020.2 release © 2005-2021, Xsens Technologies B.V. All rights reserved. Information in this document is subject to change without notice. Xsens, Xsens DOT, 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.
Table of Contents Table of Contents ................................................................................. iii Abbreviations and Terms ......................................................................... x Default Folders ................................................................................... xi 1 Introduction ................................................................................... 1 2 Content overview ..............................................................
.2.2 4.2.3 5 Dongle License Key .................................................................................12 Network License Key ...............................................................................13 Hardware .................................................................................... 14 5.1 MVN Link ...................................................................................................14 5.1.1 Motion Trackers (MTx) ...................................................
7.2.11 Sync ...................................................................................................37 General Settings ..........................................................................................37 7.3 7.4 Configuring the Video Camera .........................................................................37 7.4.1 Configuration ........................................................................................37 Configuring the Awinda Station (or Sync Station) ...........
11 On-Body Recording....................................................................... 65 11.1 Configuration ..............................................................................................65 11.2 Calibration and recording ...............................................................................65 11.3 Import Recordings .......................................................................................65 11.4 Swap Trackers ...............................................
15.3 FBX ..........................................................................................................86 15.4 MVNX .......................................................................................................87 15.4.1 MVNX backwards compatibility ...................................................................94 15.5 Export Movie ..............................................................................................95 15.6 Export Excel ..................................
22.2 CE Declaration of Conformity MTw2, Awinda Station, Awinda Dongle ....................... 113 22.3 FCC Statements ........................................................................................ 114 22.4 FCC Declaration of Conformity MTw2 .............................................................. 115 22.5 FCC Declaration of Conformity Awinda Station ................................................... 116 22.6 FCC Declaration of Conformity Awinda Dongle ..............................
23.13 System block diagrams ............................................................................. 143 23.13.1 MTw ............................................................................................... 143 23.13.2 Awinda Dongle .................................................................................. 143 23.13.3 Awinda Dongle ANT ............................................................................ 144 23.13.4 Awinda Station ...................................................
Abbreviations and Terms Abbreviation / Term Description API Application Programming Interface AP Access Point: The method of transporting data from the body pack to the PC BP Body Pack, on-body controller unit for the motion trackers, connects to power and wireless transmission of data to host PC via the Access Point .BVH Biovision Hierarchy character animation file format .C3D Coordinate 3D export format Character Subject in 3D view .
Default Folders Description Files Location Main program mvn_studio64.exe C:\Program Files\Xsens\Xsens MVN \MVN Studio Documentation MVN Quick Setup Sheet.pdf C:\Program Files\Xsens\Xsens MVN \Documentation ii MVN User Manual
1 Introduction The Xsens MVN inertial motion capture system is an easy to use, cost efficient system for full-body human motion capture. MVN is based on Xsens' state-of-the-art miniature inertial sensors and wireless communication solutions combined with advanced sensor fusion algorithms, using assumptions of biomechanical models. MVN is a completely portable system; it is not restricted to a studio or lab. It can be used anywhere: outside, in the office, and on the work floor.
2 Content overview 2.1 MVN Link suitcase with contents Figure Figure 1: Suitcase containing the MVN Link System Description The MVN Link System arrives in a strong, durable and watertight case. The case has wheels and an extendable handle for easy transportation. The suitcase dimensions meet the requirements for most airline hand-luggage.
2.3 Body Pack (BP), Battery Pack, and Access Point (AP) Figure Figure 3: Body Pack (BP) Description Figure 3 shows the Body Pack (BP). The strings of MTx’s are interconnected by the Body Pack. It delivers power from the battery pack to the connected MTx’s and retrieves their data ensuring exactly synchronized samples. For more information about the Body Pack, see Section 5.1.2. Figure 4: Access Point (AP) Figure 4 shows the Access Point.
Figure 6: Suitcase containing the MVN Awinda System The MVN Awinda arrives in durable neoprene case with protective frame, which contains: 17(+1) Wireless Motion Trackers (MTw) 1 Awinda Station 2 Awinda Chargers MTw full body Velcro straps, including 3 shirts, headband, footpads, 2 pairs of gloves 1 Segmometer Quick Setup sheet The MVN Awinda Starter arrives in durable neoprene shell case with protective frame, which contains: 17 Wireless Motion Trackers (MTw) 1 Awinda Dongle with Antenna
Figure Description The MVN Awinda Charger is capable of charging six motions trackers. Charging from empty to full takes about one hour. Figure 11: MVN Awinda Charger The 6 3way usb charging cables plus the 6 port USB hub are capable of charging 18 motions trackers. Charging from empty to full takes about one hour. Figure 12: 6 3way usb charging cables plus 6 port USB hub 2.9 “The Suit” Depending on the system, either a Lycra suit or a set of mounting straps are provided.
The motion trackers are secured to the extremities – the head, hands and feet, using a headband, gloves and a foot pads, as can be seen in the figures below. Accessories for placing motion trackers on the extremities Figure 16: Headband Figure 17: Gloves Figure 18: Foot Pads 2.11 Software The MVN system is controlled by a software application called MVN Analyze/Animate. MVN Analyze/Animate is a 64-bit application for Windows 10.
3 Getting started 3.1 Installation of software Note: Do not connect your MVN System (either Access Point or Awinda Station) until software installation is complete (software installation includes installation of relevant drivers which can be finalized, when the hardware is connected). Run the downloaded MVN Installer (mvn_studio#_setup.exe). Install with “Administrator” rights. Follow the on-screen instructions. See 4.1 for details. 3.
Press the button on the Body Pack once to power on the device, a pulsing fading LED, solid LED, beep and finally blinking LED indicate the startup process. See Section 5.1.2. If using the MVN Awinda (starter) system: Connect the Wireless Master (see chapter: 2.7) to the computer or laptop Turn on the trackers by pressing the button until each LED is activated and begins to flash Place the straps and trackers on the body (for more information on putting on the straps, see section 5.4). 3.
MVNX is a human readable, XML format which can be imported to many other software programs, including MATLAB and Excel. This format contains the most information, including the sensor data, segment kinematics and joint angles, as well as the subject information needed to recreate a 3D visualization of a character. See Section 15.4. Movie Exporter is an mpeg-4 (.mp4 or .avi) video export tool which contains a capture of the character’s live motion as configured in the display window.
alter the properties of the physical motion sensors, which may cause the device to become inaccurate. 3.5.3 Suit, shirt, short maintenance To wash the suit, shirt, shorts remove all cables, BP and MT’s. Follow the instructions on the label inside the suit: Description Machine wash at 30°C – 85 F Icon Do not bleach Do not iron Do not dry clean Do not tumble dry For the headband and gloves, remove the MTx and use only cold hand wash. 3.5.
Use only the manufacturer’s power supply and observe terminal polarity. Place the charger in a cool spot, away from external heat sources Caution - during recalibration the charger may become warm. 11 www.xsens.
4 Software As mentioned in Section 2.11, the MVN system is controlled by MVN Analyze/Animate. The installer of the software can be downloaded from https://www.xsens.com/softwaredownloads. The instructions below detail the installation procedure. 4.1 Software Installation Note: Do not connect your MVN System (either Access Point, Awinda dongle, or Awinda Station) until software installation is complete. Run the downloaded MVN Installer (setup.exe).
Extension licenses or upgrade licenses can be activated on the dongle using the Software Activation tool, which can be started from Start Menu > Xsens MVN 20xx.x> Xsens MVN 20xx.x > Software Activation. 4.2.3 Network License Key When using a network license key, the red dongle needs to be used on a pc (server) that is running a service called ‘Sentinel LDK License Manager’. This service needs to be started by running an installer, which can be downloaded from: Xsens website: https://www.xsens.
5 Hardware 5.1 MVN Link The standard MVN System consists of a combination of hardware and software. The previous section described how to install the software. The following will provide an overview of the hardware, which includes the MTx’s, Body Pack, Sync Station and Access Point; and how to assemble the devices into the mounting system (Lycra suit or MVN Mounting straps). 5.1.
On the bottom of the Body Pack, there are 3 connectors: One Ethernet connector which can be used for cabled recordings, when the system is directly connected to the recording PC rather than transferring data via wireless signal A micro USB connector, supported for future use to configure the BP The BP is powered by a single Battery Pack (rechargeable smart Lithium Ion battery pack). The Battery Pack has a typical operating time of 9.
A successful WPS is indicated by a beep and the BP LED will return to intermittent flashing. Any Router that supports WPS can be connected to a Body Pack. See the Tutorial video “WPS connection”. Click the address for a direct link to the tutorial. https://tutorial.xsens.com/video/wps-connection 5.1.2.5 Soft Access Point To make the MVN Link system really portable you can connect the Body Pack directly to a laptop or tablet.
5.1.3 Battery Charger The CH5000 is a standalone desktop smart, standard battery charger with the added ability to recalibrate the fuel gauge on smart battery packs. 5.1.3.1 Using your Charger Place the charger on a flat, level surface away from sources of heat and moisture. Plug the DC connector from the power supply into the back of the charger and connect the power supply to the mains AC supply using the cable supplied. Figure 24: Battery charger 5.1.3.
To recalibrate the fuel gauge, press the button on the front of the charger. The charger will automatically begin to charge the battery if the button is not pressed. The blue LED will flash to indicate that the battery is undergoing the recalibration cycle. During calibration the discharge resistors will be cooled by the fan. Removing the battery, or pressing the calibration button again will re-start the process from the beginning.
5.1.4 Access Point (AP) The MVN System comes with one Access Point (AP) which handles the data traffic between the BP and the computer. The Access Point should be connected to the PC via Ethernet cable through the Ethernet port or using the supplied Ethernet to USB adapter. Figure 25: Access point 1. LAN 1~4 LED Off: No power or no physical connection. On: Has physical connection to a local area network (LAN). 4. 2.4GHz LED / 5GHz LED a. Off: No 2.4GHz or 5GHz signal. b. On: Wireless system is ready.
Place the wireless router in a centralized area for a maximum wireless coverage for the network devices. Keep the device away from metal obstructions and away from direct sunlight. Keep the device away from 802.11g or 20MHz only Wi-Fi devices, 2.4GHz computer peripherals, Bluetooth devices, cordless phones, transformers, heavyduty motors, fluorescent lights, microwave ovens, refrigerators, and other industrial equipment to prevent signal interference or loss.
Note that if synchronizing with a third party device sending 5V, it is advised to purchase (from e.g. Farnell) a 3.3 - 5V / 5V - 3.3V SMD level translator to prevent damage to the Sync In ports of the Sync Station. 5.2 MVN Awinda / MVN Awinda Starter 5.2.1 Wireless Motion Trackers (MTw) The MTw provides 3D angular velocity using rate gyroscopes, 3D acceleration using accelerometers, 3D earth magnetic field using magnetometers, as well as atmospheric pressure using the barometer.
Flushing Stand-by Double pulse in sync with Awinda Station (CONN LED). OFF. Blinks for 3 s, if motion has been detected, while searching for a radio connection. 5.2.3 MTw Stand-by Mode Following a wireless connection to the Awinda Station or Dongle, the MTw enters measurement mode. If the radio of the Awinda Station or Dongle has been switched off for longer than 30 seconds the MTw will enter stand-by mode.
SyncOut port is fine. Therefore unless a threshold of 5V of the third party system is required, in which case the 3.3V-5V SMD level translator will be required. For software configuration of the synchronization channels, see Section 25. 5.2.7 Awinda Station Status LED The Awinda Station has five LED indicators. From right to left, these indicators are: Label CHRG Led OFF [CHaRGer functionality] STAT Description When no mains power supply is connected to the Awinda Station.
5.2.8 Awinda USB Dongle Figure Description The Awinda USB dongle has the same wireless capabilities as the Awinda Station, in that it can accurately control the reception of data of up to 32 MTw’s. Figure 31: Awinda USB dongle Given that the Dongle does not have an external antenna its range is shorter than the Awinda station; indoor/outdoor 10/25m (30/75ft).
Straps are suitable for a majority of the adult population and can be placed directly on the skin for the close contact, or on top of the clothing for comfort. If worn over clothing, it is advisable to wear relatively tight-fitting clothes. Figure Figure 33: MTw side view Description The motion trackers are provided with a code indicating segment position. ‘L’ or ‘R’: left or right side of the body. Segment: An abbreviation of the segment name.
Other clothing can be worn on top, no connection or line-of-sight is needed to the external world other than the wireless data link. Follow these steps to put on the suit: Important: The zip is at the front of the Lycra suit. Do not pull aggressively on the material, work gradually from the feet to the neck. 5.3.2.1 Putting on the Lycra suit Below are a few simple steps to help put on the Lycra suit. Again it is advised to watch the video on the tutorial portal for more detailed, visual information.
correctly than with the Straps. Therefore please refer closely to the following information to ensure the best placement. The table below describes the positioning of the motion trackers.
6 MVN Analyze/Animate MVN Analyze/Animate is easy-to-use software, which can be used for real-time viewing and recording. Off-line playback, analyzing and editing of previously recorded sessions are also possible with MVN Analyze/Animate. Figure 36 shows a typical view of MVN Analyze/Animate when a recording has been made. Figure 36: MVN Analyze/Animate interface The main tool bar at the top of the MVN Analyze/Animate interface is displayed in Figure 37 below.
6.1 Status Bar At the bottom of the MVN Analyze/Animate interface is the status bar. It is important to pay attention to the icons shown here, as they give important information about the status of the system.
7 Workflow and Functionalities in MVN Analyze/Animate MVN Analyze/Animate is designed for optimal flow of the steps required for recording and analyzing motion. Different workflow items become active at various stages. Figure 40: The workflow toolbar gives the user an optimal interface setup per functionality: Hardware and Fusion Setup, preview and record, playback and editing and analysis 7.1 New session A new session is created during the workflow stage “Hardware and Fusion Setup”.
hardware can be configured in the Hardware Status panel (see 7.6) and the Navigator panel is described in 7.7. Tutorial video about setting up a recording session: https://tutorial.xsens.com/video/set-up-a-recording-session 7.2 Configure an MVN System For each of the four possible MVN Systems, the user can configure the individual settings. Note that the Sync Settings dialogue is available only with an MVN Analyze license. 7.2.
Suit Configuration Picture (green = active sensors, blue = inactive sensors) Full Body Number of Sensors 17 Max Update rate – MVN Awinda (Hz) 60 Max Update rate – MVN Link (Hz) 240 Full Body no hands 15 60 240 Lower Body 7 100 240 Upper Body 11 60 240 Upper Body no Hands 9 100 240 Lower Body with Sternum 8 100 240 32 www.xsens.
7.2.6 Scenario Depending on the type of measurement you will carry out, select the type of scenario that will ensure the best results, and minimize post-processing. The scenarios available include: Scenario Single Level Multi Level No Level Soft Floor Vehicle Description This scenario assumes that the subject will be walking on level terrain This scenario assumes that the subject will be walking on terrain or varying height, e.g. climbing stairs.
the time of the measurement) in order for MVN Analyze/Animate to calculate other segment lengths (based on an anthropometric model). Note: A recording cannot be performed if the user does not insert these values; then the following error will be shown 5 (Figure 43). Figure 43: Error if recording attempted without subject height and foot length. In addition to these basic measurements, other body segment dimensions can be adjusted for subject-specific anthropometry.
Dimension Description Body Height Ground to top of head when standing upright Foot or Shoe length Length of feet or length of shoes if wearing shoes Shoulder Height Ground to C7 spinal process Shoulder Width Right to left distal tip of acromion (acromial angle) Elbow Span Right to left olecranon in T-pose Wrist Span Right to left ulnar styloid in T-pose Arm Span Tip of right fingers to tip of left fingers in T-pose Hip Height Ground to most lateral bony prominence of greater trochanter Hip
Generally the motion tracker on the prop is detected automatically when clicking ‘Apply’ in the Prop Configuration window. If this does not occur, go to Tasks >Re-initialize suit(s). The prop mesh (the on-screen image of the prop sensor) can be connected to any defined point on a body segment. The prop can be rotated freely but will always follow the position of the selected point.
7.2.11 Sync With MVN Awinda, the dialogue to configure the sync settings is in the MVN System configuration. To configure the Sync Station which is the method for synchronizing MVN Link with third party devices, the sync settings are configured via the Sync Station tab, see 7.5 . It is worth noting that sync with MVN Awinda is tighter than with MVN Link due to the tight control of the Awinda Station over the MVN Awinda System. For detailed information regarding sync settings, refer to section 25. 7.
Figure 46: Example of camera configuration window If no pictured is displayed, if the image is jagged, or no camera is found, install the dedicated driver, found in C:\Program Files\Allied Vision Technologies. You may have to restart MVN Analyze/Animate for the camera to be found after this is installed. If no video data is displayed, check or uncheck the Use jumbo packets option to resolve the issue.
7.5 Configuring the Awinda Station (or Sync Station) The Awinda Station as part of the MVN Awinda setup can also be used for synchronizing between MVN Link and third party systems. The user will note that when MVN Link is selected, the text beside Sync Settings states “Not sync capable”. The Awinda Station (or Sync Station) must be inserted for synchronization with MVN Link (Figure 47). Figure 47: Sync settings Click 25. to configure the sync settings.
7.6 Hardware Status To view the Hardware Status, Select the in the configuration window. Hardware status shows a list of all trackers and masters detected by MVN Analyze/Animate. The figures below show the hardware status interface and Table 1 details the meaning of the colored markers. This menu can be edited while the Configure Session window is also open, instructions for editing can be found below. When the Configure Session is not open, this interface is read-only.
7.6.1 Relocating motion trackers Each Xsens motion tracker has a unique location ID which relates them to the limb segment they should be placed on. If for some reason, a tracker has the wrong ID assigned to it, e.g. if an additional motion tracker is detected or a broken MT needs to be replaced with a spare, this can be done easily by reassigning the MT’s ID to the desired position. To assign a tracker to a different segment, drag and drop the ID to the Location, or vice versa.
7.6.2 MVN Awinda: Changing Radio Channel For MVN Awinda users, the Hardware Status is necessary in order to configure the network detection status of the system. Figure 48 Shows a list of motion trackers expected to be found by the MVN Awinda system. The icons of these trackers are black indicating that they are expected but not yet detected. As the Awinda Station is searching for MTw’s, the CONN LED of the Awinda Station, or the white LED of the Awinda USB dongle blinks rapidly.
Again, in the Hardware Status window, either right click or double click the number under the letters “Ch”. If a user attempts to make a connection in an existing configuration between an Awinda Station and a tracker used for the first time the option “Forget System” should first be selected. After this command, all trackers (including previously rejected ones) can connect again. When all devices necessary for the suit configuration are detected, the 3D character will appear in the 3D viewport.
8 Setup The setup workflow stage consists of three parts; it shows the subject’s body dimensions (see 7.2.9), data fusion and sensor to segment calibration. The calibration procedures are only available once the MVN system is connected and the 3D Character has appeared in the view port. When a file has been recorded this icon remains active to enable changes to body dimension inputs. Note: It is not possible to save a calibration file, when a recorded file is open.
Figure 51: Segment calibration interface 8.1.2 Apply calibration and define x-axis When the calibration data has been processed, the system will show the quality of estimated calibration parameters and show warnings in case problems were detected (see Section 8.1.4 for more information). Before applying the calibration results, the forward pointing X-axis can be defined. To do so, the user is asked to stand in N-pose facing the forward axis of the measurement environment.
Please note that it is always recommended that a calibration is performed before beginning to record data using MVN Analyze/Animate. However, it is possible to enable a measurement without calibration in the preferences menu (Options >Preferences >General >Recordings). Another option in the preferences menu is “Enable simple calibration routines” in this menu to enable the not recommended N and T-pose.
Note that a ‘good’ or ‘acceptable’ quality indication does not necessarily mean that the actual calibration is accurate. MVN Analyze/Animate can perform limited checks of the actual pose of the subject during the calibration due to a natural variation in body physique and locations of the motion trackers on the body. Therefore, always pay attention to the pose of the subject since it will influence the quality of the recording. Calibration data can be saved.
9 Preview and Recording 9.1 Preview During the Preview and Recording stage of the workflow, the viewport is active. There are a number of viewing possibilities, the 3D character in the 3D viewport and orthogonal views. Select the number of windows to view at one time. Figure 53 is an example of a four window view showing the 3D view and three different orthogonal views. To select which type to view, Right Click and select from the drop down menu, as indicated in the figure (or use the shortcut keys).
9.1.1 Viewport Icons The icons above the viewport can be selected to show and hide various parameters, as detailed below.
Fixed angle and distance (T) Horizontal Follow (T) Circle Around Character (T) Coronal posterior (X) Coronal anterior (X) Sagittal right (Y) Sagittal left (Y) Transversal cranial (Z) Transversal caudal (Z) The global heading and pitch of the camera are fixed. The height of the camera follows the height of the pelvis.
real-time graphical data, the recommended setting during real-time preview is “Expand to fit”, or “Full Fit”. 9.1.4 Save and Restore Layout To the right of the graph icon are two icons indicating the possibility to save and restore layouts of the interface. To save a layout, use the icon directly to the right of the graph icon, the layout currently in view will be saved. Give the layout a name, in the drop down menu that appears.
recording. For this reason, the recorded data is often of better quality than the real-time preview. 9.3 Add comments after recording Adding comments after a recording has finished can be very useful in a later stage when you are opening the recordings. The popup dialog to add comments after a recording can be enabled or disabled (menu > Preferences > Interface > User Interface Show popup dialog for file comments after recording).
9.4 Recovery of MVN file after system crash If MVN Analyze/Animate was shut-down as a result of a system crash, the MVN file will not be properly closed and not useable. To correct this, when you try to load the corrupted MVN file in MVN Analyze/Animate it will look for a recovery file (MVR) that can be used to recover the data captured. A message will ask if you want to use a recovery file. This file has the same name and location as the corresponding MVN file but with a “MVR” extension.
9.6 Network Streamer The network streamer sends the poses of the active window (playback or real-time), both UDP and TCP are supported by the network streamer. The UDP Protocol is unidirectional, and contrary to TCP (Transmission Control Protocol, RFC 793) it is stateless and does not require the receiver to answer incoming packets. This allows greater speed. How to set up the network streamer is explained in this tutorial video. https://tutorial.xsens.
Figure 57 above shows the Network Streamer Options. The table below summarizes the functionality of each selection. Please refer to the Real-Time Network Streaming Protocol Specification for further details.
9.7 Network Monitor MVN Analyze/Animate also implements a Network Monitor that can receive the MVN network stream of motion data. Note that this is mean only to monitor a network stream and no further functionality is provided than viewing (i.e. no saving, recording, editing etc). To open a network monitor in MVN Analyze/Animate, go to File >Open Network Monitor or press “Ctrl+M”, to obtain the menu shown in Figure 58.
10 Playback, reprocessing and editing When the data has been recorded, MVN Analyze/Animate offers several options for playback, reprocessing, video synchronization, and editing which will be discussed in this section. 10.1 Reprocess HD With MVN Analyze/Animate, a new sophisticated processing option is available called “Reprocess HD”, which includes all data in the file to get the best performance for the recorded motion. The reprocessing can be enabled by pressing ‘Ctrl+Shift+P’ or click the icon below.
window has opened, the input and output paths can be chosen with the level of reprocessing quality you desire. You can also change the number of parallel processes that are used during processing. This determines the amount of files that are reprocessed at the same time. Be advised that increasing this number will significantly increase the memory usage of MVN during reprocessing. The default setting should provide a sensible balance between CPU and memory usage.
Go to end End Shift + End 10.4 Synchronization with video In MVN Animate Pro, MVN data with synchronized video is available. The accuracy of the software synchronization depends heavily on the LAN connection to the camera and the wireless link quality to the MVN system. In general, the time offset between the MVN frame and the video frame is negligible, or less than 1-2 video frames.
During Playback and Editing, four default bars appear above the timeline, indicating presence of contact points, advanced (floor level), position, and clipping edits (Figure 62). If there is a contact, the contact will be shown in the viewport with a large blue sphere. When hovering above the ‘other contacts’ bar a tool tip pops up indicating which contact point is active. Figure 62: Contact point When clicking on a body segment with the left mouse button, the selected mesh will light up in red.
To scrub, drag the time line scroll bar ( ) to the left or right. Step through the time frames using the left and right cursor or keep it pressed to move very slowly though the file, frame by frame. Figure 63: Contact points on the 3D viewport and the contact editing menu 10.5.1 Selection of samples The left mouse button (and drag) will set a contact for the selected contact point. The color of the user-defined contact point will be slightly darker than the color of the original detected contact point.
10.5.2 Contact point editing options 10.5.2.1 Remove user-defined Revert to the original recording for the selected samples. Remove user-defined aiding refers to the positions and floor levels set, as remove user-defined contacts refers to the contact points of the segments. Reprocess to apply changes (see Section 10.5.2.6). 10.5.2.2 Ignore contacts globally Removes all detected contacts for all segments. Figure 65: Example of ignore contact globally 10.5.2.
Figure 66: Set position menu during contact point editing The SD slider sets the standard deviation, which is an indication of how much the aiding point can be trusted in combination with the computed position of the MVN Fusion Engine. This option can also be used creatively for example to create a “soft” landing on a mattress. With the ‘Force no contacts’ options, no other contacts will be detected during the selected frames.
Figure 68 for an example. Figure 68: Set floor level menu Right mouse click on a contact bar to set the floor height to the height of that contact. The contact detection will now be applied on the new floor height for all following samples. Left mouse click and drag on the advanced bar allows you to set a floor height for a range of frames 10.5.2.6 Clipping The clipping bar indicates when clipping has occurred in the data.
11 On-Body Recording On-body Recording’ allows you to record motions everywhere without the need for a laptop or PC by storing motions on the Body Pack (only for MVN Link). The Body Pack has internal memory that has the capacity to record up to 15 hours of data. This functionality is enabled by a firmware update (Body Pack firmware 1.1.4). 11.
Figure 70: import MTB files menu The bottom part of this dialog allows you to manage the recordings on your Body Pack. You can select the recording that contains the Npose + Walk or Tpose + Walk, which can then be applied to the other recordings. Body Dimensions and Scenario can be set here before you import it to a specific path on you pc. See also the tutorial on ‘Importing On-Body Recording files’: https://tutorial.xsens.com/video/importing-on-body-recording-files/ 11.
Figure 72: Swap trackers configuration Select the strings you desire to swap and click on the green and blue circular arrows, these will appear in the swapped trackers list. Select which processing mode you desire and finally click Swap. 11.5 Remote On-Body Recording The Remote On Body Recording (Remote OBR) feature allows you to synchronously trigger multiple body packs to initialize and stop the On Body Recording (OBR) functionality.
Figure 74: Bodypack Configuration interface The Access point will begin scanning for the Body Packs, once discovered, each Body Pack will appear with the Device ID and Name with the ability to select/deselect which Body Pack you want to record with. For each Body Pack the Recording status, battery status, Wi-Fi strength and Sync is also listed on the right side of the interface. The sync refers to the measured system clock deviation at the time of synchronization in milliseconds.
12 3D Position Aiding 12.1 GNSS 12.1.1 Introduction The recent addition of GNSS (Global Navigation Satellite System) to Xsens MVN allows position aiding to your inertial motion capture. The GNSS refers collectively to GPS (USA including QZSS (Japan) and GLONASS (Russia) for this 1 st release. These global positioning systems work all over the world including China and Japan, however the 1 st release does not support BeiDou, which is optimal for China.
When configuring a new session, open up the Position tab (Figure 75) and select the GNSS option. When this is enabled, the system will record and use the data collected from the GNSS antenna. The scenario can be set to 3 scenario’s: Single level, Multi level and No level.
Figure 76: GNSS set-up in MVN It is also possible to set-up the GNSS in On-Body Recording (OBR), by opening up the Configure On-Body Recording tab, selecting Data and checking the GNSS checkbox. 12.2 HTC Vive 12.2.1 Background MVN allows for position aiding with HTC Vive. With the feature, the MVN fusion engine combines the Motion Tracker data from the Motion Capture System (Link or Awinda) and the HTC Vive position tracking to improve the global position.
Vive Hardware Location Pelvis visuals Place the Vive Tracker just above Pelvis Motion Tracker Fore Arm (R/L) Place the Vive Tracker at 1/2 of the forearm (halfway from wrist to elbow) on the outer side of the arm in npose. Lower Leg (R/L) Place the Vive Tracker at 1/3 of the lower leg (one-third from the ankle to the knee) on the outer side of the arm in n-pose. Head Place the headset on the head, as if you are playing a virtual reality game 72 www.xsens.
Hand (R/L) Hold the controller in your hand as if you are holding it, playing a game 12.2.3 Setting up To work with HTC Vive as positional aiding, make sure you set up Steam, Steam VR and HTC Vive. Please follow the steps in the BASE article below. https://base.xsens.com/hc/en-us/articles/360012457659-HTC-Vive-Setup-Guide Placement of the Vive trackers on the body is explained in this tutorial: https://base.xsens.
Figure 77: Motion capture configuration - Position - HTC vive Note: An octagon will appear on the avatar to indicate the status and location of the Vive trackers: Icon Color green meaning Vive Ready and receiving position data yellow Vive Tracker ready but not receiving position data. No Vive Tracker detected black 5. In the TrackerID drop-down menu (Figure 78), select the Vive Tracker ID to attach to this actor.
Figure 78: Select the Vive Tracker ID to attach to this actor 6. Select the location on the body where the tracker is placed at the Location drop down menu. (Figure 78) Figure 2: Preview of the tracker location on the body, from left to right: pelvis, left lower leg, right lower leg, left lower arm, right lower arm 7. Click Ok to start the live session 8. Perform a regular calibration - Link (https://tutorial.xsens.com/video/calibrating-link/) - Awinda (https://tutorial.xsens.
After calibration, you are ready to record. 1. Make sure you are in the bounds of the Play Area. 2. Press the Record button (or Ctrl + R) to start the recording. 3. Press the Record button (or Ctrl + R) again to stop the recording. 4. MVN will create the following file type(s). - .mvn file: contains the Position Aided Motion Capture Data - .mvno file: contains the positional and rotational data from the Objects (only created if Object Tracking was enabled during the session, see chapter 12.2.4) - .
13 MVN Remote app for iOS and Android MVN Remote is an app that allows you to control MVN Analyze/Animate from your phone or tablet. The app can also record a reference video using the camera on the device. This video will be streamed to MVN Analyze/Animate and can be played back next to the motion that was recorded (Figure 80). https://base.xsens.com/hc/en-us/articles/360010738879-MVN-Remote-App-for-iOS-and-Android Figure 80: Remote app interface The app is available for both Android and IOS. 77 www.
14 Data Analysis The final stage of the work flow is ‘Data Analysis’. The major feature of the analysis stage is kinematic graphs. 14.1 Graphs In the analysis workflow stage, a graph appears in the interface. To view a graph of a given parameter, click and drag the parameter from tree view to the graph. Two types of graphs are possible: time vs. parameter and parameter vs. parameter (Coordination [or phase] Plots). 14.1.1 Parameter vs.
Figure 82: Time vs. Parameter on the left hand side and parameter vs. parameter on the right hand side 14.1.4 Graph handling Zoom and pan in the graph using the icons in the toolbar. The time on the time vs. parameter graphs conforms to that shown in the time bar. 14.1.
14.1.7 Zoom To zoom, select the “No auto scaling” option. Zoom only takes place on the vertical axis. To zoom in time use the mouse wheel in the time line to zoom horizontally to a point in time. 14.1.8 Pan To use the pan function, enable “no auto scaling”, click in the graph area with the left mouse button and drag up or down, to pan. Note that it is not possible to pan to an area with no data.
14.1.12 Amount and layout of graphs There are a number of pre-defined layouts available, which can be selected from the drop down menu. Additionally, there is a possibility for the user to define a custom amount and layout of the graphical representation. When “Custom” is selected, a new area appears where the user can insert the number of rows by columns to view. 14.2 Cascade / Tile windows Multiple trials can be opened simultaneously and played and edited.
15 Saving and Exporting When a recording has been made that contains more than just the motion data of a single actor (e.g. multi-actor or video), two files are created and saved automatically, one with the file extension “.mvn” and the other with the file extension “.mvns”. If synchronized video data is recorded, a movie file “.mpg” is also saved automatically. MVN (MVN native file) is the most comprehensive format and contains all measured inertial sensor data, and all kinematic data of each segment.
of the header section begins with the keyword ‘HIERARCHY’. The following line starts with the keyword ‘ROOT’ followed by the name of the root segment of the hierarchy to be defined, usually the hips. Each segment contains a vector indicating the length and direction from the parent segment. The vector is specified by the keyword ‘OFFSET’ followed by the X, Y and Z values. The ‘CHANNELS’ keyword indicates the number of channels for this segment (usually 3 Euler angles) together with the order of rotation.
not the case in the MVN Fusion Engine) some foot slide may occur since all errors such as mainly soft tissue artefacts are ‘projected’ on the feet. Further optimization can be done by using inversed kinematics (IK) solvers which are usually available in animation applications and which are also necessary for retargeting the motion data to different characters. The BVH format does not support multi-person recordings. For each person a separate BVH file will be made. Set the BVH preferences.
15.1.3 Output Presets Several Output Presets are available that fit specific applications: Motion Builder 3D Studio Max Poser 6 15.1.4 Output Unit Select the desired output unit that is used in the animation program. 15.2 C3D C3D means “Coordinate 3D”; as the name suggests it is a file format designed to contain 3D coordinate data, usually in the form of bony landmarks. It has also been designed to contain analog data.
15.2.1Points exported in C3D Exporter For an illustration of the location of the points, see Figure 93.
Figure 87: FBX Preferences Menu FBX files contain both position and orientation information of all 23 segments. The FBX file will also contain the frame time format. Go to >Options >Preferences >Exporters >FBX … and select the timestamp output mode. To store the appropriate time code in an FBX file, the FBX exporter plug-in must be set to “Dynamic time increments" and "Start at real start time” as seen in Figure 87. This figure also shows that many of the options for FBX are also applicable to BVH.
MVNX contains as default, 3D segment and position data. Additional values can be exported as Figure 88 shows, including: 3D Position, linear and angular acceleration and velocity of all 23 segments. 3D Joint angles of 22 joints. Center of Mass position of the body Contact data indicating which contact point was detected as ground contact 3D Orientation, free acceleration and magnetic field data of all 17 MT’s. Since MVN 4.0, a time code field is also available.
G Z Global frame G G Y X Figure 89: Segment coordinate system at each segment origin, as is used in MVN. Legend: x: red, y: green, z: blue This section describes the MVNX definition based on version 4 (available since MVN 4.3.7). This version contains some important fixes with respect to the previous version and it is recommended to use this version. Still, version 3 is available and can be chosen in the MVNX exporter preferences. Section 15.4.
The entire MVNX structure is as follows: X Y Z etc. etc. etc.
body); the date that the recording took place, and the filename of the original recording on which the MVNX file is based. When creating a recorded file, a user can insert a comment. This is available in the exported MVNX: (this field usually has the same contents as the comment field after the tag, see above)
The “ergonomic joint angles” section is a list of specific joint angles used in ergonomic analysis contained, and the segments and connections for each given joint: etc.
The selection in the preferences menu determines the MVNX contents. Orientation and Position are mandatory, all others are optional and may depend on the license.
The numbering is presented in the table below.
denoting the T-pose using MVN anatomical coordinate frame, and “npose” denoting the relation between the body frames of the T-pose and MVN anatomical pose. 15.5 Export Movie Exporting movie data enables the user to export the 3D viewport of MVN Analyze/Animate to either .m4v or .avi. this facilitates presenting MVN information to audiences without the need for installation of MVN Analyze/Animate, Select the export format, resolution and export frame in >Options >Preferences >Exporters >Movie Exporter.
15.6 Export Excel It is now possible to export your data into an excel spreadsheet, simply put the output path, and file name in. Under Exporter select “Excel Exporter (*.xlsx)”. And click Export. Each corresponding section of the navigator (ie. Segments, joints etc.) will have its own tab in the xlsx file, each joint/segment will have its own column, with the frames listed in the rows. 96 www.xsens.
16 Features of MVN SW licenses A range of additional features become available when using another license for MVN system. Additionally, the MVN Animate and MVN Analyze software has been restructured into: - Basic: free to download software, to create MVN files - Plus: stream to your third party software - Pro: all features included See the full comparison of the different Basic, Plus and Pro licenses below. Features for Animate: https://www.xsens.com/compare/mvn-animate Features for Analyze: https://www.
17 MVN Ethernet Camera MVN Analyze/Animate has the ability to record synchronized MVN and video data. This is possible using the Ethernet camera (Prosilica GS650) provided with the PRO system. The camera is a high quality professional GigE camera with a C mount. The GigE interface enables the use of long cables (max 100m) and standard 1 Gigabit Ethernet cards for interfacing.
18 Xsens Peripheral Software 18.1 Magnetic Field Mapper (MFM) When a motion tracker is mounted to an object that contains ferromagnetic materials, the measured (Earth) magnetic field can become distorted, causing errors in measured orientation.
4. Click “Next” and browse to the V2C files you have received to open it The license is activated/updated. 18.4 Software Activation Tool: Applying an Update You can use the Software Activation tool to apply an update to the licenses stored in your Sentinel protection keys. To update the licenses in the Sentinel protection keys: 1. Launch the Software Activation tool from the start menu or help menu in MVN Analyze/Animate 2. Click “Show advanced options”. 3. Click “Apply license file (V2C)”. 4.
How to active a network license: https://base.xsens.com/hc/en-us/articles/360012632119-How-to-activate-a-NetworkLicense 101 www.xsens.
19 Troubleshoot Problem Device driver error Awinda Station with docked MTw’s results in "Driver Software Installation" error. See figure to the right displaying the pop-up warning: The suit does not connect. Solution This is a timing issue because Xsens motion trackers send data to the PC continuously to guarantee a fast set up time. To solve, remove the tracker from the station then redock. Check battery levels. Check ‘Hardware status’ menu (Section 7.6). Check Suit configuration (Section 7.2.
Character sticks to the ground or segments are pulled apart (wrongly detected contacts). Enter correct body dimensions of subject (Section 7.2.9). Perform new calibration pose. Choose suitable user scenario (default is flat ground assumption) (Section 7.2.6). Character appears to bounce slightly when no movement is taking place. Make sure the feet trackers are mounted rigidly. This is likely to be caused by visualization rather than data issues.
Change the radio channel. (See 23.11.1) With MVN Awinda there appears to be a large latency MTw LED shows dual blink pattern When connecting 2 or more MVN Awinda systems, MTw’s assign to the wrong awinda station This does not happen often, if it does it means that the MTw has crashed. To restore to normal, switch it off, by pressing the button for 6s. Press it for 1s to turn it back on. Begin by connecting one Awinda station and turn on the MTw’s for the system associated with this receiver.
20 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 2 years 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 support: base.xsens.com for return material authorization (RMA) prior to returning any items for calibration, repair or exchange.
21 Regulatory Notices MVN Link 21.1 Radio Frequency Exposure and Emission The MVN Link system contains a small radio transmitter and receiver. During communication with other Wi-Fi products system receives and transmits radio frequency (RF) electromagnetic fields (microwaves) in the frequency range 2400 to 2500 MHz or 5200 to 5700MHz. The output power of the radio transmitter is very low. When using the system, you will be exposed to some of the transmitted RF energy.
21.2 EU Declaration of Conformity MVN Link 107 www.xsens.
21.3 EU Certificate of Conformity for Radio Equipment MVN Link 108 www.xsens.
21.4 FCC Statement MVN Link Note: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications.
21.5 FCC Declaration of Conformity MVN Link 110 www.xsens.
21.6 Japan Certificate of Conformity for Radio Equipment MVN Link 5GHz product for indoor use only using frequencies within 5.15-5.35GHz. The product may be used indoor and/or outdoor using frequencies within 5.47-5.72 GHz. 111 www.xsens.
22 Regulatory Notices MVN Awinda 22.1 Radio Frequency Exposure and Emission The MTw2, Awinda dongle and station contains a small radio transmitter and receiver. During communication with the Awinda Master it receives and transmits radio frequency (RF) electromagnetic fields (microwaves) in the frequency range 2400 of 2500 MHz. The output power of the radio transmitter is very low. When using the system, you will be exposed to some of the transmitted RF energy.
22.2 EU Declaration of Conformity MVN Awinda 113 www.xsens.
22.3 FCC Statement MVN Awinda This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications.
22.4 FCC Declaration of Conformity MVN Awinda 115 www.xsens.
22.5 Japan Certificate of Radio Equipment MTw2 116 www.xsens.
22.6 Japan Certificate of Radio Equipment Awinda Station 117 www.xsens.
22.7 Japan Certificate of Radio Equipment Awinda Dongle 118 www.xsens.
23 Appendices 23.1 Lycra suit sizes overview The typical height and weight of a subject that will fit into a given suit size is related. While this is generally accurate, it is an indication, therefore test the suit size, to ensure that it is tight enough to keep MTx’s in place during measurement while remaining relatively comfortable.
and both and represent the standard dot and cross product, respectively. Be aware that the order of multiplication is important. Quaternion multiplication is not commutative, meaning: q1 q 2 q 2 q1 23.2.
Figure 90: Body planes 121 www.xsens.
23.4 Coordinate systems The MVN Fusion Engine calculates the position and orientation, and other kinematic data of each body segment, B, with respect to an earth-fixed reference co-ordinate system, G. By default, the earth-fixed reference co-ordinate system used is defined as a right handed Cartesian co-ordinate system with: Global reference frame: X positive when pointing to the local magnetic North (red). Y according to right handed co-ordinates (West) (green). Z positive when pointing up (blue).
23.5 Anatomical model 23.5.1 Definition of segment axes To describe motion capture data in clinically meaningful data, e.g. joint rotations, it is necessary to define a coordinate reference frame attached to the body segment. The ISB proposal for standardization for joint coordinate systems is currently based on positions (optical markers) of bony landmarks. For most segments on the body, the origin of the reference frame and direction of axes are described in Wu and Cavanagh (1995) [i] Wu et al.
a b Figure 92: a) Segment coordinate system at each joint origin, as is used in MVN to determine joint angles. b) Joint centers connected, forming a skeleton Legend: x: red, y: green, z: blue Note that positions of anatomical landmarks are not measured directly as they are with optical measurement systems. They are computed using the measured accelerations, angular velocities and rotations in combination with the biomechanical model.
Upper body T8, ribcage, neck and shoulders Right arm and shoulder Left leg and foot Pelvis, L5 and right upper leg 125 www.xsens.
pPIJ pPX Figure 93: Selection of anatomical landmarks. Above, anterior view. Below, posterior view. 23.6 Segment axes definitions and Origin Definitions Note: To ease comparison between the MVN segment co-ordinate systems with the International Society of Biomechanics recommendation, currently based on optical 126 www.xsens.
position tracking systems, the ISB recommendation is presented next to the MVN definition. The MVN segment axes definition and origins have been chosen as closely as possible to the ISB recommendation where whenever possible. MVN ISB [ii] O Midpoint between right and left hip center of rotation Coincident with hip center of rotation X Perpendicular to Y and Z Line parallel to a line lying in the plane defined by two ASISs and midpoint of two PSIS, orthogonal to Z-axis.
23.6.2 Neck: Segment 6 MVN ISB O jT1C7 Not described in ISB X Perp. to Y and Z Pointing forward Y jT1C7 to jC1Head Z Pointing right Note: The neck segment is not measured directly in MVN; it is calculated using a model of the neck. 23.6.3 Head: Segment 7 MVN ISB O jC1Head Not described in ISB X Perp. to Y and Z Y jC1Head to TopOfHead Z Left Ear to Right Ear Note: Position of Ears are not measured but assumed to be on the same height. 23.6.
23.6.5 Upper Arm (Humerus): Segment 9 Right and Segment 13 Left There are two segment coordinate systems described in ISB. The system described below is option 1. O MVN ISB [iii] jRightUpperArm GH GH jLeftUpperArm GH X Y Sagittal plane Line perp. Plane EL-EM-GH Pointing forward Pointing forward Right: jRightElbow to jRightShoulder Line connecting GH to mid point ELEM Left: jLeftElbow to jLeftShoulder Pointing to GH Z Perp. to X and Y Line perp.
Note: In MVN, the joint center is the midpoint between the styloids. No metacarpals are measured in MVN. This description is for the anatomical pose. When the subject stands in the N-pose, X will no longer point anteriorly, but medially. 23.6.
Tibia. In the MVN model the lateral and medial epicondyles and lateral and medial malleoli are the same height. 23.6.10 Foot (Calcaneus): Segment 18 Right and Segment 22 Left O MVN ISB [ii] jRightAnkle IM jLeftAnkle IM X Sagittal plane forward Line perp. to frontal plane of tib/fib in neutral configuration. Pointing anteriorly. Y Vertical (aligned with gravity, pointing up) Line coincident with long axis of tibia/fibula, in neutral configuration. Pointing cranially Z Perp.
standards for rotation sequences for the lower [Wu et al, 2002ii] and upper body [Wu et al 2005iii]. 23.7.1 Euler Extractions for the joint angles In order to produce validated joint angle output, Xsens MVN works closely to the ISB and Grood and Suntay recommendations [i,ii,iii,vi]. Almost all angles follow the ISB Euler angle extractions of Z (flexion/extension), X (abduction/adduction) Y (internal/external rotation).
to-segment calibration procedure to an estimate of sensor orientation, and applying a (scaled) biomechanical model of the human body. Each of these components will introduce errors, but the most dominant error source are generally the magnetic distortions which are present anywhere (e.g. common materials in buildings, furniture, and surrounding electronic equipment).
The intentional difference in terminology is needed to highlight that data from new Xsens motion trackers (MTx and MTw) undergoes a mathematical method called Strap Down Integration. This ensures that no loss of accuracy is experienced, even though the data is transmitted to the PC at lower update rates. Update rates as low as 20 or 30Hz still provides very accurate data. 23.
Figure 94: Overview of channels operating around 2.4GHz; for ease of channel selection 135 www.xsens.
23.12 System Specifications Recommended computer system Operating system Windows 10 (64 bit) Processor Quad core or higher (2.7 GHz or faster) Hard drive SSD 256 GB or more Memory 8 GB RAM (64-bit) Graphics card Hardware acceleration for DirectX 11 Dedicated memory 512 MB or more Network card Gigabit Ethernet, support for jumbo frames (9014 Bytes) USB ports USB 2.
Communication Interface Wireless (WiFi or Awinda Protocol) Wireless range radius (max) MVN Awinda Station Awinda dongle Outdoor 150 meter (492 ft.) ~50m (164 ft.) ~20m Indoor open space 150 meter (492 ft.) ~20m () ~10m Indoor office 50 meter (164 ft.) ~20m () ~10m Wireless receiver units: MVN Link MVN Awinda Number of Wireless Receivers 1 Access Point 1 Awinda Station or Awinda Dongle RF technology WiFi 2.4GHz, 5.0 GHz IEEE 802.15.4 PHY 2.4GHz Interface Ethernet USB 1.1 or 2.
Environmental Operation environment 0 – +50 deg Celsius, non-wet Humidity 20-80%RH NC Tracker Performance Static accuracy (Roll/Pitch) 0.2 deg Static Accuracy (Heading) 0.5 deg Dynamic Accuracy 1 deg RMS Accelerometer range MTx: ± 160 m/s2 (16 g) MTw: ±160m/s2 (16g) Gyroscope range ± 2000 deg/s MVN Performance MVN human model MVN uses a 23 segment biomechanical model with 22 joints. Each joint is specified by statistical parameters for 6DOF joint laxity.
MVN Fusion Engine 3D translation capture ~1% error in traveled distance (without external aiding). Advanced external contact model detects body-world contacts, to enable crawling, sitting, cartwheel etc. Various friction models (slippage etc.) are possible.8 Seamless fusion with aiding technologies possible, e.g. 3D position from optical/GPS, or 2D image correspondences.8 Magnetic environment Full immunity to any magnetic distortion.
Package Label 140 www.xsens.
23.13 System block diagrams 23.13.1 MTw The purpose of the MTw wireless motion tracker is to give accurate orientation data. This is done by sampling digital sensors and processing this data at an MCU (Microcontroller unit) to angular velocity, acceleration, magnetic field and barometric pressure information. The MTw functions as a slave in a wireless network. It transmits the data by the RF front end (CC2541 +CC2590) wireless via AWINDA™ protocol to the AWINDA master.
23.13.3 Awinda Dongle ANT The AWINDA dongle works as a master and together with the MTw it forms a wireless motion tracker system. The AWINDA dongle communication is based on CC2541 hardware, using a proprietary TDMA (Time Division Multiple Access) AWINDA™ protocol. Figure 97: Awinda Dongle ANT block diagram 23.13.4 Awinda Station The AWINDA station works as a master in a Local wireless sensor network. Together with the MTw it forms a wireless motion tracker system.
24 Contact point editing For examples of contact point editing please check this link: https://base.xsens.com/hc/enus/articles/360013009559-Contact-Point-editing 143 www.xsens.
25 Synchronization with External Devices 25.1 The Hardware MVN Awinda uses the Awinda Station for synchronization. Details on initializing the synchronization of MVN are provided in Section 7.2.9. The purpose of this section is to provide some in-depth information about the synchronization possibilities. The Awinda Station was originally created as a wireless master to control the Xsens MTw kit.
25.2 Sync In Sync In means that an external device sends a control signal to the Awinda Station. The Awinda Station can detect polarity changes on the input lines. This trigger may be a rising or falling edge as illustrated in the following figures: When a trigger is detected on one of the input lines, the Awinda Station can be configured to perform a certain action.
25.3 Sync Out Sync Out is the command that enables the Xsens system to send a trigger pulse for synchronization purposes. A control signal is sent via the Awinda/Sync Station, from MVN Analyze/Animate to the third party hardware.
25.3.1 Settings in MVN Analyze/Animate By opening the motion capture configuration window and select sync station configuration (Figure 99) Figure 99: Sync settings window in MVN Analyze/Animate To add a synchronization type, click “Add”, all settings become available, to be set manually or using the drop down menus. An example and the how to set up a 3rd party sync is explained in the tutorial video and base article below. https://tutorial.xsens.com/video/setting-up-a-sync-station/ https://base.xsens.
25.4.1 Sync In Recommended Settings Note that the preferences menu includes “Skip first” and “Skip Factor”. The definitions of these have been provided above; however for practical use consider the following: When the Awinda Station is triggered to start and stop a recording, on one line, it will blindly receive 3.3 V pulses on that line. Since all pulses are the same, the Station requires further instructions about what to do with each pulse.
25.9 Gloves Manus: https://base.xsens.com/hc/en-us/articles/360017254919-Setting-up-ManusPrime-2-Gloves-with-MVN StretchSense: https://base.xsens.com/hc/en-us/articles/360017745539-StreamingStretchSense-Glove-Data-into-MVN 149 www.xsens.
26 References i Wu G, Cavanagh PR (1995). ISB recommendations for standardization in the reporting of kinematic data. J. Biomech. 28: 1257-261 ii Wu G., Siegler, S., Allard, P., Kirtley, C., Leardini, A., Rosenbaum, D., Whittle, M., D’Lima, D., Cristofolini, L., Witte, H., Schmid, O., Stokes, I., (2002). ISB recommendation on definitions of joint coordinate system of various joints for the reporting of human joint motion—part I: ankle, hip, and spine. J.
