System for monitoring traffic conditions in connection with the control thereof

• US 3,906,438 A
• Filed: 02/14/1973
• Issued: 09/16/1975
• Est. Priority Date: 02/17/1972
• Status: Expired due to Term

• Current Assignee: Dietrich Kohnert
• Original Assignee: Dietrich Kohnert
• Inventors: Kohnert, Dietrich
• Primary Examiner(s): Claffy, Kathleen H.
• Assistant Examiner(s): Myers, Randall P.
• Application Number:
  US05/332,258
• Time in Patent Office: 944 Days
• Field of Search: 340/31A,31R,37,38R,38L,41R 235/150.24
• US Class Current: 340/934
• 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 monitoring traffic flow on streets having at least two traffic lanes free from oppositely directed traffic, particularly highways, wherein each traffic lane can be monitored, at least at one common location, by respective vehicle detectors, in which the magnitudes of time intervals between successive vehicles at the associated detector are measured, and mean values thereof are formed, together with mean values of another representative corresponding magnitude between successive intervals, with the values being stored in respective memories and supplied therefrom over linking means with a differenceforming device, together with similar values from other detectors, in predetermined timing with the output of the difference-forming device providing an evaluatable magnitude related to the traffic flow.

Claims

1. A system for monitoring traffic flow on streets having at least two traffic lanes free from oppositely directed traffic, particularly highways, wherein each traffic lane can be monitored, at least at one common monitoring location, by respective vehicle detectors, comprising for each detector a measuring system for deriving representative magnitudes of time intervals between successive vehicles at the associated detector, means for forming values representative of such magnitudes and comprising a mean value device to which interval magnitudes are supplied, and a memory for storing successive mean interval values derived from said mean value device, the output of said value forming means supplying such representative values, comparison means for effecting a predetermined comparison function between a plurality of representative values, and means operatively connecting corresponding outputs of the respective value-forming means of a plurality of said detectors to said comparison means for comparison of the respective representative values of said detectors, the output of said comparison means being operative to provide an evaluatable output magnitude related to the traffic flow.

2. A system according to claim 1, comprising in further combination, timing means, operatively connected with said measuring system, operable to simulate a vehicle by providing an impulse if time intervals of a certain magnitude are exceeded.

3. A system according to claim 1, wherein said comparison means comprises a quotient-forming device to which said representative values are supplied.

4. A system according to claim 1, wherein the representative values supplied to said comparison means are from different detectors of the same monitoring location.

5. A system according to claim 4, wherein in further combination, a further means forming device is provided, to which the output of said said comparison means is supplied, the output value of which provides an evaluatable output magnitude.

6. A system according to claim 5, comprising in further Combination a further memory for storing the output values of said further mean value forming device, further comparison means to which the output of said further memory is supplied, along with a similar output from another monitoring location, the output of such further comparison means providing an evaluatable output magnitude.

7. A system according to claim 6, wherein said further comparison means comprises a difference-forming means, the output of which supplies an evaluatable output magnitude.

8. A system according to claim 1, wherein said value-forming means for each vehicle detector includes means, to which are supplied other magnitudes different from said first-mentioned magnitudes, but also representative of time intervals between respective vehicles at the associated detector, operative to modify such second magnitudes to form second corresponding representative values, a second mean value forming device to which said last-mentioned representative values are supplied, a second memory for storing successive mean values derived from said second means forming device, and linking means for effecting a predetermined comparison function between mean values in said second memory with the mean interval values stored in said first memory of the associated detector, the output magnitude of said last-mentioned means comprising the output of said value-forming means and supplied to said comparison means as the representative value of such detector, which is to be compared with a corresponding value from another one of said detector.

9. A system according to claim 8, wherein the representative magnitude supplied to said modifying means comprises a difference value between the preceding mean interval value and the next interval value.

10. A system according to claim 8, wherein said linking means comprises a product-forming device.

11. A system according to claim 8, wherein said modifying means comprises a product forming device operative to form the square of such other representative magnitudes.

12. A system according to claim 8, wherein said modifying means comprises a product-forming device operative to form the square of such other representative magnitudes.

13. A system according to claim 8, wherein said first means value forming device is operable to also provide the difference value between a newly received interval magnitude and the mean value of the immediately previous interval, which difference value is modified by said modifying means and forms said second representative corresponding magnitude and which is supplied to said second mean value forming device, the linking means between the respective memories therefor and said comparison means including a product-forming device to which the output values of such memories are supplied, said comparison means comprising a quotient-forming device to which the output value of said product-forming device is supplied, and to which is also supplied the output value derived from another of said detectors, the output value of such quotient-forming device being supplied to a further mean value forming device, the output value of which is supplied to one input of further comparison device means, the other input of which is connected by further linking means to memories associated with a plurality of other detectors.

14. A system according to claim 13, wherein means are provided for the respective mean value forming devices, for adding the product of a selected factor and the difference between the previously respectively stored mean value and the new measured value, to the stored old mean value.

15. A system according to claim 13, comprising in further combination, timing means, operatively connected with said measuring system, operable to simulate a vehicle by providing an impulse if time intervals of a certain magnitude are exceeded.

16. A system according to claim 13, wherein the output value supplied from said first comparison means to said further comparison means, is also supplied to additional cOmparison means, to which is supplied the immediately previous corresponding value from said last-mentioned further mean-forming device, the outputs of both said further and additional comparison means comprising evaluation magnitudes related to the traffic flow.

17. A system according to claim 16, wherein each of the mean-forming devices associated with the mean interval magnitude and the mean difference value has operatively connected thereto means for altering the associated difference value, between a new magnitude and the previous value, by a predetermined factor, the factors for the respective mean-forming devices having different values.

18. A system according to claim 17, wherein said modifying means comprises a product-forming device operative to form the square of such other representative magnitudes.

19. A system according to claim 18, wherein said difference forming device is operable to evaluate at predetermined times, the contents of memories of a monitoring location, and operatively connected with at least two associated traffic detectors.

20. A system according to claim 18, wherein said difference forming device is operable to evaluate the contents of memories of two monitoring locations which can be simultaneously supplied, under control of the timing means, and operatively connected with at least two associated traffic detectors.

21. A system according to claim 18, wherein the memories of a single monitoring location are interlinked by means of a quotient-forming device during the evaluation of only a like type of mean time values, and both memories of a detector are interlinked by means of a product forming device, in the case of a common evaluation of different types of mean time values.

22. A system according to claim 18, wherein means are provided for the respective mean value forming devices, for adding the product of a selected factor and the difference between the previously respectively stored mean value and the new measured value, to the stored old mean value.

23. A system according to claim 13, wherein said modifying means comprises a product-forming device operative to form the square of such other representative magnitudes.