Active Marker Tracking: Firmware v0.8

Main PageActive Marker TrackingActive Marker Tracking: Firmware v0.8

Page Scope

This page provides instructions on how to set up and use the OptiTrack active marker solution. Note that this guide is specific only to the pre-programmed OptiTrack active LED marker kit, and the instructions will not work with third-party LEDs. This solution is supported only for the Ethernet camera systems (Slim 13E or Prime series cameras).
  • This guide covers Firmeware v0.8 only.


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Compatibility Notes: Firmware Version

We strongly recommend updating the firmware on the active tracking components: Base Station and Tags. Please contact support for instructions on how to update the outdated firmware.
Firmware v0.8
  • Active components that were shipped prior to September 2017 uses the firmware v0.8.
  • v0.8 Base Station works only with v0.8 Tags.
  • Firmware v0.8 requires an eSync to synchronize the base station and the mocap system together.
  • Whenever v0.8 Base Station is power cycled, all of the v0.8 Tags must be power cycled as well.
  • v0.8 Base Station is not compatible with v1.0 Tags
Firmware v1.0
  • Active components that were shipped later than September 2017 uses the firmware v1.0.
  • No longer requires eSync for synchronizing the Base Station with the camera system.
  • Support for user-defined camera framerates.
  • The illumination time of active LEDs is synchronized to the camera exposure time.
  • Allows changing the depth of illumination patterns, allowing a higher number of active markers to be actively labeled
  • Compatible only with Motive 2.0 beta 2 or later versions.
  • v1.0 Tags are compatible with v1.0 Base Stations only.
  • For instructions on the v0.8 firmware, go to the following page: Active Marker Tracking: Firmware v1.0
Using v0.8 Tags with v1.0 Base Stations
  • v0.8 Tags needs to be power cycled each time you close and relaunch Motive.
  • v0.8 Tags needs to be power cycled each time system frame rate has been changed in Motive.

Overview[edit]


The OptiTrack Active Marker Kit allows synchronized tracking of active LED markers using an OptiTrack camera system. The Active Marker Kit consists of the Base Station, the Tags, and the Active LED markers, and it requires the eSync 2 with an Ethernet camera system. Once everything is setup, the Base Station becomes the sync master for both the camera system and the active markers. It sends out sync signals via RCA output and radio frequency waves allowing precise synchronization between camera shutters and illumination of the Active LED markers. The synchronized illumination allows labeling of individual markers in Motive.

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  • Active Marker Kit works with Ethernet camera systems (Prime series and Slime 13E cameras). Integration with USB camera systems (Flex series) is not supported.
  • Currently, the Base Station can only send out 180 Hz sync signal.

Active Labeling[edit]

When using the OptiTrack Active Marker Kit, active markers are labeled individually from their unique illumination patterns, and only the correctly labeled active markers get contributed to the rigid body solve. The biggest benefit of individual marker labeling is that the markers can be placed in a perfectly symmetrical arrangement among multiple rigid body assets that share similar placements. Each marker labeled through this the active labeling method is represented with marker IDs less than 5000 in Motive.

  • ActiveMarkers Illuminating.JPG
  • ActiveMarkers Motive 2.png

Required Components[edit]


Name Image
eSync 2 Synchronization Hub

The synchronization hub for the camera system. (The eSync 1 can also be used)

ESync2Pic.png
Base Station

Used as the sync master for both the active LED markers and the camera system. It sends out sync signals via RCA output and RF emitter for synchronizing the eSync and the Tags.

BaseStation.png
Tag

The Tags receive RF signals from the Base Station and correspondingly synchronizes illumination of connected active LED markers.

Tag.png
Active LEDs

Emits 850 nm IR light. 4 active LEDs in each bundle and up to two bundles can be connected to each Tag.

(8 Active LEDs (4(LEDs/set) x 2 set) per Tag)

Size: 5 mm (T1 ¾) Plastic Package, half angle ±65°, typ. 12 mW/sr at 100mA

ActiveLEDs.png

Sync Setup[edit]


Follow the below steps for synchronizing and tracking the active markers in Motive.

eSync 2 and Base Station[edit]

Setup Steps[edit]

  1. Connect the eSync 2 to the camera network using an Ethernet cable.
  2. Connect the eSync 2 and the Base Station. Use an RCA cable to connect the output port (white) of the Base station into the Input 3 port on the eSync. You will need to use an RCA-BNC adaptor (included with the eSync 2) to do this.
  3. Open Motive
  4. [Motive] Go to the synchronization pane.
  5. [Motive > Synchronization] Use the dropdown menu to switch to the Custom Synchronization mode.
  6. [Motive > Custom Synchronization] Set the Input Source to Reserved. (The Base Station should be connected to the Input 3 port of the eSync, but the Reserved setting corresponds to an alternative mode of operation specific to the BaseStation).
  7. [Motive > Custom Synchronization] Click Apply. Now the cameras will be synchronized to the signal from the Base Station (master) which will also synchronize the active markers.
ActiveTracking Setup 20.png

Base Station Signal[edit]

The Base Station sends out radio frequency waves for synchronizing the active markers. The following is the specification of the RF signal:
  • RF: 802.15.4 @ 2.4 GHz
  • Channel 20
  • The Base Station sends out the RF signal every 10th frame of the camera system.

Tag + Active Markers[edit]

Setup Steps[edit]

  1. Once the Base Station and the eSync are set by following the above steps; now you can setup the active markers.
  2. Connect two sets of active markers (4 LEDs in each set) into the Tag.
  3. Power the Tag. Use a micro USB cable to connect the Tag to a power source.
  4. Once powered, you will see the LEDs illuminating in red.

Tag Power[edit]

Each Tag requires power from a micro USB cable. The power requirement is between 2.7V - 5.5V. Measured at 100mA @ 5V with all LEDs on for every frame.

Motive[edit]

  1. Now that the hardware components and the synchronization are set up, the last step is to tell Motive that it needs to look for active markers. This can be set in the Application Settings pane.
  2. [Motive > Application Settings > Reconstruction] Under the Reconstruction tab in the Application Settings, set the Marker Labeling Mode to either Active Marker Only or Active and Passive.
  3. [Motive > Application Settings > Reconstruction] Also, make sure Utilize Active Label is set to True,.
Active marker tracking configuration.

Troubleshooting[edit]


› Q : The synchronization pane indicates that the camera system is synchronized to the Base Station. However, the active markers are flickering from both the 3D viewport and 2D camera views in Motive.

A: First of all, make sure the Application Settings is configured for tracking active markers. If the flickering of markers persists, it indicates the camera system and active LED markers are incorrectly synchronized. This usually occurs when power cycling the Base Station or when synchronization settings are altered in Motive. You can fix this by power cycling the Tags.

› Q : In the Synchronization pane, no input signal is detected.

A: Make sure the sync output (white) of the base station is connecting to the Input 3 of the eSync 2. Then, Motive must be configured to sync to the Reserved source.