ELECTROMAGNETIC LOOP VEHICLE DETECTORS - RADAR, ACOUSTIC AND MAGNETIC VEHICLE DETECTORS - FUTURE VEHICLE DETECTION CONCEPTS

THREE DIFFERENT ELECTROMAGNETIC-LOOP VEHICLE-DETECTOR DESIGNS ARE DESCRIBED: SELF-TUNING, BRIDGE BALANCE, AND PHASE-SHIFT. PRINCIPLES OF OPERATION, DESIGN LIMITATIONS, AND DESIGN TRADEOFFS FOR EACH METHOD ARE PRESENTED IN DETAIL. VARIATIONS IN THE CHARACTERISTICS OF THE LEAD-IN WIRE ARE THE PRIMARY LIMITATION OF LOOP DETECTOR PERFORMANCE AND STABILITY. CHARACTERISTICS OF COMMERCIALLY AVAILABLE WIRE USED IN PRESENT-DAY LOOP DETECTOR INSTALLATIONS ARE DISCUSSED. DESIGN EQUATIONS AND GRAPHS ILLUSTRATE THE TRADEOFF CONSIDERATIONS IN THE DETERMINATION OF OPTIMUM LOOP CONFIGURATION AND INDUCTANCE. THREE DIFFERENT PHENOMENA ARE DISCUSSED AS APPLIED TO THE DETECTION OF ROADWAY VEHICULAR TRAFFIC. THESE DETECTORS ARE THE INPUT DATA SOURCE FOR VEHICLE-ACTUATED TRAFFIC SIGNAL LIGHT CONTROL MECHANISMS, CONTROL SYSTEMS, FREE-WAY SURVEILLANCE, AND STATISTICAL ANALYSIS. RADAR DETECTORS USING MICROWAVE RADIO FREQUENCIES IN THE 2.5-10 MHZ ARE DISCUSSED WITH REGARD TO OPERATING PRINCIPLES, DESIGN CONSIDERATION, AND PRATICAL APPLICATION. SIMILARLY, ACOUSTICAL DETECTORS OPERATING IN THE 20 KHZ RANGE AND LOW-FLUX DENSITY CHANGE MAGNETIC DETECTORS ARE DISCUSSED. A COMPARATIVE ANALYSIS IS MADE OF RADAR, ACOUSTICAL, AND MAGNETIC DETECTORS, AS WELL AS MECHANICAL, MAGNETIC, INDUCTION, AND OPTICAL DETECTORS. THIS PAPER PRESENTS SOME OF THE ECONOMIC AND TECHNICAL CONSIDERATIONS FOR DEVELOPMENT OF FUTURE NONCOOPERATIVE VEHICLE-DETECTOR SYSTEMS. VEHICLE-DETECTOR ACCURACY REQUIREMENTS, INSTALLATION COST, LOCATION, AND THE ROADWAY ENVIRONMENT ARE USED TO DEVELOP A SET OF PREFERRED VEHICLE-DETECTOR CHARACTERISTICS. IN ADDITION, A DESCRIPTION OF VEHICLE DETECTORS, CONSIDERED FOR DEVELOPMENT BY THE BUREAU OF PUBLIC ROADS, AND SOME OF THE CURRENT VEHICLE-DETECTOR CONCEPTS UNDER DEVELOPMENT, ARE PRESENTED, VIZ., INDUCTION COIL DETECTOR (SENSES ELECTRICAL NOISE GENERATED BY THE VEHICLE) FIELD ASYMMETRY SENSING TECHNIQUE (USES TWO ORTHOGONAL COILS), AND RF DETECTOR (AIMS A RADAR BEAM AT THE UNDERSIDE OF A CAR). /AUTHOR/

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00189545
• Supplemental Notes:
  • Vol Vt-19, PP 23-30, 30-43, 43-49
• Authors:
  • Anderson, R L
  • Barker, J L
  • Mills, M K
• Publication Date: 1970-2

Media Info

• Serial:
  • IEEE Transactions on Vehicular Technology
  • Publisher: Institute of Electrical and Electronics Engineers (IEEE)
  • ISSN: 0018-9545
  • Serial URL: http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=25

Subject/Index Terms

• TRT Terms: Acoustics; Coils (Electromagnetism); Design; Electromagnetism; Highway traffic; Loops (Control systems); Radar; Vehicle detectors
• Uncontrolled Terms: Characteristics
• Old TRIS Terms: Loops (Electrical); Vehicular traffic
• Subject Areas: Design; Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00225866
• Record Type: Publication
• Source Agency: Traffic Systems Reviews & Abstracts
• Files: TRIS
• Created Date: Dec 2 1970 12:00AM