The '092 patent is directed towards a pulsed time-of-flight laser range finding system used to obtain vehicle classification information. The sensor determines a distance range to portions of a vehicle traveling within a sensing zone of the sensor. A scanning mechanism made of a four facet cube, having reflective surfaces, is used to collimate and direct the laser toward traveling vehicles. A processing system processes the respective distance range data and angle range data for determining the three-dimensional shape of the vehicle.
Independent Claim 1 describes "a system for determining the three-dimensional shape of a vehicle, the system comprising: a sensor for generating a plurality of laser beams and for detecting a plurality of reflected beams, each of said reflected beams corresponding to one of the plurality of generated laser beams; a controller in data communication with said sensor to trigger the generation of the laser beams at predefined scan angles; and a processing system to determine distance ranges from the sensor to portions of the vehicle for each of said scan angles using time-of-flight measurements derived from timings of said generated laser beams and reflected beams, when the vehicle travels within a sensing zone of the sensor and to determine a three-dimensional shape of the vehicle based on distance ranges, wherein said processing system comprises at least two time-to digital converters (TDCs) for performing said time-of-flight measurements and wherein, during a scan, said processing system is configured to switch back and forth between each of said TDCs such that eight reflected beams may be received in no more than 70 nanoseconds.”