Large Linear Treadmill

The linear treadmill setup consisted of three main components: the treadmill itself (Bonte Technology, Netherlands), a four camera Vicon® MX-13 optical tracking system, and a visualization system that displays 3D graphics in a head-mounted display (see Figure). All three components were controlled by separate dedicated computers.

The linear treadmill measured 6 x 2.4 m (L x W) and was capable of speeds up to 40 km/h. It was controlled from a pc via a CANbus connection. The treadmill could be controlled in either open loop or closed loop mode. For the closed loop control, the position of the user on the treadmill was measured with the Vicon® system, which tracked infrared-reflecting markers on the helmet worn by the user. Based on the position of the helmet and its change over time the speed of the treadmill was adjusted in order to keep the user on the treadmill. The Vicon® data were also used to update the visual input, matching the head movements made by the user. The large linear treadmill was located adjacent to the multi-agent lab.