Intelligent vehicle highway multi-lane sensor

• Main Authors: ROBERT E. MCCONNELL II, KEITH L. FOWLER, KEVIN A. KREEGER, RICHARD J WANGLER, ROBERT L GUSTAVSON
• Format: Patent
• Language: English
• Published: 11.05.1998
• Edition: 6
• Subjects: ANALOGOUS ARRANGEMENTS USING OTHER WAVES; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION ORRERADIATION OF RADIO WAVES; MEASURING; PHYSICS; RADIO DIRECTION-FINDING; RADIO NAVIGATION; SIGNALLING; TESTING; TRAFFIC CONTROL SYSTEMS

An Intelligent Vehicle Highway System (IVHS) sensor (100) 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. The sensor (100), a diode-laser-based Vehicle Detector And Classifier (VDAC) measures the presence, speed, and three-dimensional profiles (128) of vehicles passing beneath it within its multi-lane field-of-view coverage. The sensor (100) uses pulsed laser range imaging technology adapted for determining the three-dimensional profile (128) of the vehicle. A rotating polygon mirror system (300) is used to scan a pulsed laser rangefinder beam across vehicle traffic la nes of a highway (102) in order to measure the presence, speed, and height profiles of vehicules (104) in all lanes simultaneously. A receiver (400) accepts reflections from beams transmitted from the sensor (100) and provides inputs for determining time of flight, and a time interval between interceptions of the two divergent beams, a first beam (106) and a second beam (110) for the vehicle. An encoder tracks the position of a mirror (302) for providing angle data with associated range measurements. High signal-to-noise ratio and good spatial resolution result in highly accurate traffic-parameter measurements.