Camera pose estimation with a two-dimensional marker Grid for haptic navigation

We developed a computer-vision-based position and orientation tracking system for pedestrian navigation with a mobile haptic display. Our developed system tracks the user´s hand and provides the user with a haptic directional cue for way-finding. An off-the-shelf web camera is rigidly affixed to the haptic display the user holds and faces the ceiling where fiducial markers are displayed. The three-dimensional position and orientation of the device can be calculated from the known position and orientation of the fiducial markers that appear in the captured image. The performance of the system was verified using simultaneous measurement comparisons with a high-precision commercial motion capture system.