초록 ▼

An Intelligent Vehicle Highway System (IVHS) sensor provides accurate information on real-time traffic conditions that can be used for incident detection, motorist advisories, and traffic management via signals, ramp meters, and the like. A diode-laser-based Vehicle Detector And Classifier (VDAC) me

An Intelligent Vehicle Highway System (IVHS) sensor provides accurate information on real-time traffic conditions that can be used for incident detection, motorist advisories, and traffic management via signals, ramp meters, and the like. A diode-laser-based Vehicle Detector And Classifier (VDAC) measures the presence, speed, and three-dimensional profiles of vehicles passing beneath it within its multi-lane field-of-view coverage. The sensor uses pulsed laser range imaging technology adapted for determining the three-dimensional profile of the vehicle. The VDAC employs a rotating polygon mirror to scan a pulsed laser rangefinder across three lanes of a highway in order to measure the presence, speed, and height profiles of vehicles in all three lanes simultaneously. A receiver accepts reflections from beams transmitted from the sensor and provides inputs for determining time of flight, and a time interval between interceptions of the two divergent beams for the vehicle. An encoder tracks the position of the mirror for providing angle data with associated range measurements. The VDAC high signal-to-noise ratio and good spatial resolution result in highly accurate traffic-parameter measurements.

대표청구항 ▼

[ What is claimed is:] [1.] A sensor useful in determining the shape of a vehicle, the sensor comprising:laser rangefinder means for determining a range from the sensor to points on a vehicle when the vehicle travels within a sensing zone and for providing range data outputs corresponding to sensor

[ What is claimed is:] [1.] A sensor useful in determining the shape of a vehicle, the sensor comprising:laser rangefinder means for determining a range from the sensor to points on a vehicle when the vehicle travels within a sensing zone and for providing range data outputs corresponding to sensor angles for ranges from the sensor to the points on the vehicle;means for scanning the laser means within a plane generally orthogonal to a direction of travel for the vehicle, the scanning means communicating with the laser rangefinder means for determining a range for a corresponding point on the vehicle within the transverse plane, the scanning means providing means for determining the range and a corresponding sensor angle for each point within the scanning plane;deflecting means cooperating with the scanning means for deflecting the scanned beam from a first position to a second position, the first and second positions defining a forward beam and a backward beam through which the vehicle travels; andmeans for processing the ranges, corresponding angles, and interception times for the vehicle receiving the first and second beams, the processing means providing a vehicle image profile representative of the vehicle.