摘要 |
<p>Capturing the path of an object moving through a sensing volume defined by a three-dimensional (3D) coordinate system. First, second, and third angle detectors (705, 735, 755) are mounted in a common housing positionable at a vertex of a sensing cone encompassing the sensing volume (130), said first, second, and third detectors being separated from one another by known, fixed distances. Each detector receives a respective light beam (704, 734, 754) from the object having a respective angle relative to a respective reference line of the 3D coordinate system, and provides a signal corresponding to said respective angle. At successive samples, successive coordinate positions of the object within the sensing volume are determined, given the first, second, and third angles at each said sample to determine said path, and the path is displayed.</p> |