Surveillance system for monitoring traffic in localized areas of a route

• US 3,922,636 A
• Filed: 07/02/1973
• Issued: 11/25/1975
• Est. Priority Date: 07/07/1972
• Status: Expired due to Term

• Current Assignee: Henri Billottet, Jean-Raymond Narbaits-Jaureguy
• Original Assignee: Henri Billottet, Jean-Raymond Narbaits-Jaureguy
• Inventors: Narbaits-Jaureguy, Jean-Raymond, Billottet, Henri
• Primary Examiner(s): Wilbur, Maynard R.
• Assistant Examiner(s): Montone, G. E.
• Application Number:
  US05/375,470
• Time in Patent Office: 876 Days
• Field of Search: 343/6A,6R,6.5SS,6.5R,112TC,5PD,6.5LC 340/152T,312,24
• US Class Current: 340/993
• CPC Class Codes: B61L 25/025 Absolute localisation, e.g. providing geodetic coordinates
• CPC Class Codes: G08G 1/01 Detecting movement of traffic to be counted or controlled G08G1/07 - G08G1/14 take precedence

Abstract

A system for the surveillance in localized areas of objects moving along a route is described which includes detectors distributed along the route to be kept under surveillance; each of these detectors is connected by a multi-core cable to a control post which individually interrogates the detectors and processes the information supplied by them.

Claims

1. A system for surveying traffic along a route, comprising:

a plurality of detectors fixedly disposed along said route, each of said detectors having an operating range limited to a predetermined route section respectively assigned thereto;

a communication channel linking all said detectors;

a control post connected to said channel;

signal-generating means at said control post operable to emit over said channel an address code identifying a selected detector;

address-decoding means at each detector connected to said channel for recognizing the corresponding address code;

answer-back means at each detector connected to said channel for transmitting a characteristic signal to said control post in an operative condition of the detector;

monitoring means at each detector including a transmitter connected to said address-decoding means and provided with a first antenna for sending out electromagnetic wave energy in reponse to said corresponding address code, a receiver provided with a second antenna loosely coupled to said first antenna for feeding back wave energy to said answer-back means in said operative condition, and threshold means between said receiver and said answer-back means for discriminating between a relatively high energy level indicative of the proximity of a vehicle and a relatively low level indicative of the absence of vehicles from the assigned route section; and

indicator means connected to said channel at said control post for distinguishing between the absence of a characteristic signal, a low-level characteristic signal and a high-level characteristic signal from any detector addressed by said signal-generating means.

2. A system as defined in claim 1 wherein each detector includes an address memory forming part of said address-decoding means, said answer-back means being connected to said address memory for transmitting the address code of the respective detector to said control post along with said characteristic signal.

3. A system as defined in claim 2 wherein said indicator means comprises a display device translating said characteristic signal and the accompanying address code into markings indicative of the presence of a vehicle in any of said route sections, said markings being visually correlated with respective detectors.

4. A system as defined in claim 1 wherein said channel comprises a cable with a first conductor for address codes emitted by said control post and a second conductor for characteristic signals originating at said detectors.

5. A system as defined in claim 4 wherein said control post is provided with power-supply means, said cable including a third conductor connected to said power-supply means for energizing the equipment of said detectors.