AUTOMATIC VEHICLE MONITORING SYSTEM

• US 3,757,290 A
• Filed: 03/12/1971
• Issued: 09/04/1973
• Est. Priority Date: 03/12/1971
• Status: Expired due to Term

• Current Assignee: Gerald F. Ross, John J. Morrone, William W. Bell III
• Original Assignee: Gerald F. Ross, John J. Morrone, William W. Bell III
• Inventors: Ross, Gerald F., Morrone, John J., Bell, William W. III
• Primary Examiner(s): Claffy, Kathleen H.
• Assistant Examiner(s): Myers, Randall P.
• Application Number:
  US05/123,516
• Time in Patent Office: 907 Days
• Field of Search: 340/22,23,24,31R,32,33,38R,38S 343/6.5R,6.8R,6.5SS,1CS,112R,112PT,112TC 179/41A 325/16,117
• US Class Current: 340/991
• CPC Class Codes: G08G 1/202 Dispatching vehicles on the basis of a location, e.g. taxi dispatching

Abstract

A cooperative fleet vehicle location monitoring system utilizes low-energy-level coded impulse transmissions characterizing possible vehicle locations along a route to permit an impulse receiver aboard the cooperating vehicle to cause generation of coded transmissions receivable at a headquarters control location repeatedly identifying the vehicle and its location.

Claims

1. A vehicle monitoring system for signalling to a central station the presence of a cooperating vehicle at any one of a plurality of predetermined locations comprising:

a plurality of independent electromagnetic impulse transmitter means for continuously illuminating said respective discrete predetermined locations, each said impulse transmitter means being characterized by transmitting signal impulses having a distinctive impulse repetition frequency for identifying its respective predetermined location, electromagnetic impulse receiver means aboard said cooperating vehicle for counting the number of said signal impulses received in a predetermined time interval, encoder means responsive to said electromagnetic impulse receiver means for forming an encoded representation of said number of said signal impulses received in a predetermined time, and vehicle borne transmitter means responsive to said encoder means for transmitting said encoded representation to said central station for identification thereat of said location of said vehicle when illuminated by said electromagnetic impulses.

2. Apparatus as described in claim 1 including means cooperating with said vehicle borne transmitter means for transmitting representations to said central station for identification thereat of said vehicle.

3. Apparatus as described in claim 1 wherein said vehicle borne transmitter means further includes omnidirectional antenna means.

4. Apparatus as described in claim 1 wherein said electromagnetic impulse receiver means comprises:

electromagnetic impulse receiver antenna means, biased diode means for converting said electromagnetic energy impulses collected by said receiver antenna means directly into amplified current impulses, and means for converting said amplified current impulses directly into output pulse signals having durations substantially longer than said amplified current impulses.

5. A communication system adapted for receiving impulse transmissions having a distinctive repetition frequency characterizing a particular vehicle location comprising:

vehicle mounted omnidirectional antenna means for collecting said impulse transmissions when said vehicle is at sAid location, biased diode circuit means connected to said omnidirectional antenna means for converting said collected impulse transmissions directly into amplified current impulses, pulse shaping means connected to said diode circuit means for forming corresponding output pulse signals having durations substantially greater than said amplified current impulses, counter means for counting the number of said output pulse signals occurring in a predetermined time for identifying said location of said vehicle, and transmitter means responsive to said counter means for encoding the output of said counter means and for transmitting said encoded output of said counter means directly to a central station for identification thereat of said particular vehicle location.

6. Apparatus as described in claim 5 further including means cooperating with said transmitter means for transmitting representations to said central station for identification thereat of said vehicle.

7. Apparatus as described in claim 5 wherein said pulse shaping means connected to said biased diode circuit means for forming corresponding output pulse signals having durations substantially greater than said amplified current impulses is coupled in feed back relation to said biased diode circuit means for assuring extinction of current flow through said biased diode circuit means at a delayed time after the start of each amplified current pulse.

8. Apparatus as described in claim 7 wherein said counter means for counting the number of said output pulse signals occurring in a predetermined time comprises:

a gate circuit having input, output, and control means, means for coupling said output pulse signals to said gate input means, interrogator control means coupled to said control means for causing said gate to conduct for a predetermined time period, and pulse counter means connected to said gate output means for counting said output pulse signals passed by said gate within said predetermined time.

9. Apparatus as described in claim 8 comprising:

encoder means responsive to said counter means for generating an encoded representation of the number of said output pulse signals passed by said gate within said predetermined time, and omnidirectional radiating transceiver means responsive to said encoder means.

10. Apparatus as described in claim 5 wherein said biased diode circuit means comprises:

bistable semiconductor diode means, circuit means for biasing said bistable semiconductor diode means substantially at the current conduction condition thereof, and means for coupling said impulses collected by said antenna means to said bistable semiconductor diode means for causing impulse current conduction thereof.