OptiTrack Motion Capture System

The OptiTrack Motion Capture System at SDU UAS Test Center can track hundreds of markers with millimeter precision in a 665 m³ volume. The system is installed in the hangar at HCA Airport near Odense.

Use cases

• Tracking and recording complex motion patterns of humans, drones, and robots
• Collaborative swarming studies
• Human/drone interaction studies
• Obstacle avoidance
• Indoor navigation
• Calibration and verification of IMU sensors and navigation systems.

Installation

The system is comprised of fourteen Optitrack 17 W cameras mounted on a 12x12 meter truss that is suspended from the ceiling of the Test Center’s hangar. The installation covers an area of 144 m² and the total effective capture volume is 665 m³ (11 x 11 x 5.5 m).

How does it work?

The motion capture technology works by using highspeed greyscale cameras for tracking passive or active markers that are illuminated with infrared light. In tracking mode, the cameras use bandpass filters tuned to around 860 nm wavelength to locate and track the markers.

Passive Markers can be reflective balls as small as 6.7 mm or just pieces of reflective tape. These are illuminated by the camera’s high power infrared LED ring light. Active markers are 860 nm IR LEDs with different strobe patterns. These can be used to achieve better labeling and higher marker sensitivity.

Each camera tracks the markers and the more cameras see the same marker, the higher the accuracy gets. In the central part of the volume, the tracking error is less than 0.5 mm, on average for the whole volume it is less than 1 mm of tracking error. The system allows to track hundreds of markers simultaneously.

The cameras track the markers locally and sends the data over a gigabit ethernet to a workstation where the final tracking solution is calculated and delivered with an average latency of 4.5 milliseconds at up to 360 Hz. For high accuracy timing the system allows to sync to the timecode of the cameras to achieve accurate timing with external applications. Motion patterns can be recorded, edited, replayed or streamed to external applications and processors.

Users

The OptiTrack Motion Capture system is part of the UAS Test Centers facilities in HCA Airport and its primary users are companies, university researchers, PhD students and students from the Faculty of Engineering at SDU.

As part of the UAS Ability drone infrastructure, it is also available for external companies and partners on a rental basis.

Contact

Jussi Hermansen System integration Lab manager, SDU UAS Center Phone: (+45) 93507396 Email: juhe@mmmi.sdu.dk

Location

SDU UAS Test Center, Beldringevej 252, 5270 Odense