Accuracy of object tracking based on time-multiplexed structured light

Our research group is currently developing a new optical head tracking system which utilises infrared laser light to measure features of the soft tissue on the patient’s forehead. These features are intended to offer highly accurate registration with respect to the rigid skull structure by means of compensating for the soft tissue. In this context, the system also has to be able to quickly generate accurate reconstructions of the skin surface. For this purpose, we have developed a laser scanning device which uses time-multiplexed structured light to triangulate surface points. This paper shows, that time-multiplexed structured light can be used to generate highly accurate reconstructions of surfaces (RMS error 0.17 mm, Kinect: RMS error 0.89 mm). Moreover, we used our laser scanner for tracking of a rigid object to determine how this process is influenced by the remaining triangulation errors. It turned out that our scanning device can be used for high-accuracy tracking of objects (RMS errors of 0.33 mm and 0.12 degrees).