Automatic vehicle identification system and method

• US 4,532,511 A
• Filed: 09/02/1981
• Issued: 07/30/1985
• Est. Priority Date: 10/12/1979
• Status: Expired due to Term

• Current Assignee: Jerome H. Lemelson
• Original Assignee: Jerome H. Lemelson
• Inventors: Lemelson, Jerome H.
• Primary Examiner(s): Groody, James J.
• Application Number:
  US06/298,743
• Time in Patent Office: 1,427 Days
• Field of Search: 340/146.3 K, 340/38 R, 340/47, 340/23, 340/572, 340/989, 340/993, 340/941, 340/933, 235/92 WT, 235/435, 343/6.5 R, 343/55, 246/29 R, 246/122 R, 382/69, 377/9, 455/2, 358/84, 358/139
• US Class Current: 340/933
• CPC Class Codes: B61L 25/043 using inductive tags
• CPC Class Codes: B61L 25/045 using reradiating tags
• CPC Class Codes: G01S 13/78 discriminating between different kinds of targets, e.g. IFF-radar, i.e. identification of friend or foe G01S13/75, G01S13/79 take precedence
• CPC Class Codes: G07B 15/063 using wireless information transmission between the vehicle and a fixed station identification of vehicles G08G
• CPC Class Codes: G08G 1/017 identifying vehicles G08G1/015, G08G1/054 take precedence

Abstract

An automatic vehicle identification system for use in identifying and routing vehicles, such as railway cars or other vehicles which routinely travel a given track or path. A passive electronic device or electrical circuit is employed to intersect an energy field and respond thereto by generating a code in accordance with energy received and converted to coded electrical signals. Connected to the passive device is a short wave transmitter for transmitting signals generated by the electrical device when so energized. The electrical device may also comprise a plurality of different induction coils or antenna which serve to modify an energy field in a given manner, which modification may be detected by short wave sensing and converted to a coded electrical signal which is employed to identify the vehicle. In another form, a coded array of antenna or induction coils is provided which modify energy fields generated at check points or scanning locations along a trackway or roadway, wherein such energy field modifications are sensed at each such scanning location, resulting in the generation of an electrical code at each location and identification of the vehicle.

Claims

1. A method of tracking objects comprising:

generating an energy field at a fixed location in a tracking area, which energy field is composed of a number of discrete and fixed radio frequency signals of different frequencies,

disposing different coded arrays of passive tuned electrical circuits on a plurality of objects to be tracked which objects may pass said known location, and wherein each of said coded arrays of circuits defines a code which is different from the codes defined by the other objects so that each object has an array of such circuits which is different from the arrays of circuits defining the codes of the other objects, and

when an object with a coded array of tuned electrical circuits comes within a given range of said fixed location in said tracking area, indicating the presence of said object thereat by detecting the presence of its tuned electrical circuits by sensing the absorption of energy of said field by said passively tuned circuits and generating a corresponding electrical signal for each frequency of the field which experiences energy absorption, and

generating a code signal defined by the combination of said tuned electrical circuits detected when said object is within said given range of said field and employing said code signal to indicate the presence of said object at said known location.

2. A method in accordance with claim 1 including generating a code signal which is indicative of the location of said energy field in said tracking area when said coded array of circuits comes within a given range of said known location and the energy field thereof.

3. A method in accordance with claim 1 wherein each of said coded arrays of circuits is disposed in a single housing, further including securing said housings at predetermined locations on said objects.

4. A method in accordance with claim 3 including encapsulating said coded arrays of circuits in said housings.

5. A method in accordance with claim 1 wherein said energy field is generated by a voltage controlled oscillator operable to produce a number of discrete stable short wave frequencies defining said energy field.

6. A method in accordance with claim 5 wherein said code signal is generated by means of a staircase generator which is operable to determine the code by generating signals defining the voltage steps in its output resulting from the frequencies of the oscillator which are partly absorbed by said passive tuned electrical circuits.

7. A method in accordance with claim 1 wherein two successive indications of the absorption of energy by each of said tuned electrical circuits is received and said successive indications are compared to determine the parity of the two successive indications.

8. The method in accordance with claim 1 wherein said energy field produces said number of discrete and fixed radio frequency signals in a serial manner and wherein with said code signal defined by the combination of said tuned electrical circuits is in parallel form.