Accession Number : ADD015822

Title :   Vehicle Presence, Speed and Length Detecting System and Roadway Installed Detector Therefor.

Descriptive Note : Patent application, filed 30 Apr 93,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Scarzello, John F ; Lenko, Daniel S ; Feaga, Adam C

Report Date : 30 Apr 1993

Pagination or Media Count : 16

Abstract : An improved detector is provided for installation in a roadway surface. The detector finds utility in a highway vehicle detection system for determining vehicle presence, vehicle speed and vehicle length. First and second matched induction coil magnetic sensors are maintained at or near the roadway surface. Each of the sensors has a longitudinal axis aligned normal to the roadway surface. The first and second sensors are separated from one another by a known distance in a direction substantially aligned with a direction of traffic flow. Each of the sensors generate a differential magnetic field signature with respect to time to indicate a passing vehicle's leading and trailing edge magnetic signatures. Vehicle speed is determined by a time-distance relationship using the leading and trailing edge magnetic signatures and the known distance. Vehicle length is determined by a time-speed relationship using the leading and trailing edge magnetic signatures and the determined vehicle speed. A triaxial magnetometer maintained at a location in close proximity to the first and second sensors measures a DC magnetic field. The DC magnetic field has vertical and horizontal magnetic field components with the horizontal components including a component substantially aligned with the direction of traffic flow and a component substantially perpendicular to the direction of traffic flow. The vertical and horizontal components caused by the passing vehicle are used to determine vehicle presence

Descriptors :   *GROUND VEHICLES, *AUTOMOTIVE VEHICLES, *MAGNETIC DETECTORS, *PATENT APPLICATIONS, GROUND TRAFFIC, MAGNETIC SIGNATURES, HIGHWAYS, MAGNET COILS, MAGNETIC INDUCTION, VELOCITY, LENGTH, SURFACES, ALIGNMENT, LEADING EDGES, TRAILING EDGES, RANGE(DISTANCE), MAGNETIC FIELDS, SURVEILLANCE

Subject Categories : Surface Transportation and Equipment
      Magnetic & Electric Fld Detection & Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE