TRAFFIC MONITORING SYSTEM

• US 3,689,878 A
• Filed: 06/23/1970
• Issued: 09/05/1972
• Est. Priority Date: 06/23/1970
• Status: Expired due to Term

• Current Assignee: Keith L. Thieroff
• Original Assignee: Keith L. Thieroff
• Inventors: Keith, L. Thieroff
• Primary Examiner(s): William C. Cooper
• Application Number:
  US05/049,086
• Time in Patent Office: 805 Days
• Field of Search: 340/22,31,32,33,34
• US Class Current: 340/907
• CPC Class Codes: G01P 3/66 using electric or magnetic means G01P3/80 takes precedence; measuring short time intervals G04F8/00, G04F10/00
• CPC Class Codes: G08G 1/054 photographing overspeeding vehicles

Abstract

A pair of start and stop sensors are positioned in each lane of a multi-lane road a known distance apart and are actuable by passing cars. Individual time delay means are associated with each lane and are energized each time the start sensor of the associated lane is energized. A computing means has a cycling state and a non-cycling state, and can be energized into its cycling state only under certain conditions, e.g., by the actuation of a start sensor at a time when the associated time delay means is de-energized. Also, under these conditions, a lockout logic means functions to energize the remaining time delay means for the cycle duration, thereby preventing said certain conditions from occurring in any other lane until the computing cycle is completed. During energization of any time delay means the subsequent actuation of the associated start sensor cannot energize the computing means. However, such subsequent actuation will re-energize the associated time delay means. Therefore, since a vehicle'"'"''"'"'s front wheels pass over the start sensor before the rear wheels do, the computation cycle cannot be initiated by the rear wheels, which cycle would result in an incorrect speed computation. Other logic means cause a camera to optically track the monitored vehicle in accordance with its speed and lane, and take a picture thereof if the speed lies in predetermined ranges. Still other logic means disable the system in the event of a very slow moving vehicle, which might occur due to an accident or heavy traffic.

Claims

1. Multi-lane traffic monitoring means for a roadway having a plurality of traffic lanes, said means comprising:

in each of said traffic lanes, a first sensing means and a second sensing means, the second sensing means of each lane being spaced a predetermined distance from the first sensing means of that lane, the first sensing means of each lane being actuatable by a monitored vehicle passing thereby to generate a start-timIng signal and the second sensing means of each lane being actuatable by passage thereby of such vehicle to generate a stop-timing signal;

a plurality of delay-signal producing means each connected to receive each start-timing signal of a respective, corresponding one of the first sensing means in a given lane and responsive thereto to emit a delay-inducing signal of a first class, which signal is of a predetermined duration and which begins at a predetermined time subsequent to reception of the respective start-timing signal by the respective delay-signal producing means;

Controlling means responsive to the concurrence of actuation of the first sensing means in any given one of said lanes and a nonemitting condition of the corresponding one of the delay-signal producing means for providing a computation-initiating signal;

each of the delay-signal producing means being unaffected by the computation-initiating signal when the same has resulted from a start-timing signal from the first sensing means corresponding to that delay-signal producing means and each of the delaysignal producing means being responsive to the computationinitiating signal for producing a delay-inducing signal of a second class when the computation-initiating signal has resulted from a start-timing signal from a one of the first sensing means other than the first sensing means corresponding to that delay-signal producing means;

the controlling means being responsive to the concurrency of delay-inducing signals of the first class and delay-inducing signals of the second class to prevent generation of a computation-initiating signal during the existence of said concurrency;

computing means, responsive to the computation-initiating signal and to a subsequent stop-timing signal from actuation of the second sensing means of the same lane as that of the first sensing means, the actuation of which has been responded to by the controlling means, for producing a first output signal v representative of the velocity of the monitored vehicle;

first logic means responsive to the output signal v for producing a second output signal e if the output signal v lies within predetermined values; and

recording means responsive to the second output signal e for recording an image of the monitored vehicle.

2. Multi-lane traffic monitoring means in accordance with claim 30 comprising:

pulse generating means responsive to the output signal e for generating a signal having a predetermined duration in time; and

in which each of said plurality of delay signal producing means is responsive to said signal generated by said pulse generating means for generating a delay-inducing signal of a third class.

3. Multi-lane traffic monitoring means in accordance with claim 2 comprising:

logic control means for sensing the lane in which the monitored vehicle is traveling and responsive to said output signal v for causing said recording means to optically track said monitored vehicle and to begin said optical tracking in a sequence wherein the image of said vehicle is recorded at a predetermined time after the optical tracking begins.

4. Multi-lane traffic monitoring means in accordance with claim 30 comprising:

logic control means for sensing the lane in which the monitored vehicle is traveling and responsive to said output signal v for causing said recording means to optically track said monitored vehicle and to begin said optical tracking in a sequence wherein the image of said vehicle is recorded at a predetermined time after the optical tracking begins.

5. Multi-lane traffic monitoring means in accordance accordance with claim 1 in which said computing means comprises:

said logic means for sensing nd responding to the expiration of a time interval of a predetermined length occurring between the initiation of said computation-initiating signal and actuation of the second sensing means in a one of the lanes, actuation of the first sensing means of which lanE has been responded to by the controlling means to provide the computation-initiating signal, for periodically energizing each of said plurality of delay-signal producing means at a rate sufficient to maintain each of said plurality of delay-signal producing means in a continuously energizing state;

said second logic means being further responsive to actuation of said second sensing means of said one of the lanes by said monitored vehicle for terminating said periodic energization of each of said plurality of delay-signal producing means.

6. Multi-lane traffic monitoring means for a roadway having a plurality of traffic lanes, said means comprising:

a pair of sensing means, comprising a first sensing means and a second sensing means positioned apart a predetermined distance d in each lane of traffic, for producing start-timing and stop-timing signals, respectively, in response to actuation by passing vehicles;

a plurality of pulse generating means of a first class, one of each of said pulse generating means being responsive to each actuation of a corresponding one of said first sensing means for generating a first delay-inducing signal having a predetermined duration in time;

storage means for storing a first scalar quantity representative of said predetermined distance;

control circuit means responsive to actuation, by a monitored vehicle, of the first sensing means of any given pair of said sensing means when said pulse generating means of said first class corresponding to said first sensing means is deenergized for producing a computation initiating signal;

time measuring means energizable to measure the time interval between said computation initiating signal and the actuation of the second sensing means of said given pair of sensing means for producing a second scalar quantity representative of said time interval;

computing means having a computation cycle and responsive to the production of said second scalar quantity for dividing said first scalar quantity thereby to produce an output signal v which is representative of the average velocity of said vehicle during said time interval;

each of said plurality of pulse generating means of said first class, other than the pulse generating means of said class energized by actuation of said first sensing means, being responsive to said computation initiating signal to become energized thereby;

means responsive to the output signal v, when said signal v lies within predetermined values, for producing an output signal e; and

recording means responsive to said output signal e for recording the image of said monitored vehicle.

7. Multi-lane traffic monitoring means in accordance with claim 6 comprising:

further pulse generating means responsive to the output signal e for generating a second delay-inducing signal having a predetermined duration in time;

each of said pulse generating means of a first class being responsive to said second delay-inducing signal for generating a third delay-inducing signal.

8. Multi-lane traffic monitoring means in accordance with claim 7 comprising:

logic control means for sensing the lane in which the monitored vehicle is traveling and responsive to said output signal v for causing said recording means to optically track said monitored vehicle and to begin said optical tracking in a sequence wherein the image of said vehicle is recorded at a predetermined time after the optical tracking begins.

9. Multi-lane traffic monitoring means in accordance with claim 6 comprising:

logic control means for sensing the lane in which the monitored vehicle is traveling and responsive to said output signal v for causing said recording means to optically track said monitored vehicle and to begin said optical tracking in a sequence wherein the image of said vehicle is recorded at a predetermined time after the optical tracking begins.

10. Multi-lane traffic monitoring means in accordanCe with claim 6 and further comprising:

logic means, including said time measuring means, for sensing and responding to the expiration of a time interval of a predetermined length occurring between the initiation of said computation-initiating signal and the actuation of said second sensing means in one of the lanes, actuation of the first sensing means of which lane has been responded to by the controlling means to provide the computation-initiating signal, for periodically energizing said pulse generating means of a first class at a rate sufficient to maintain said pulse generating means of said first class in a continuously energized state;

said logic means being further responsive to actuation of said second sensing means of said one of the lanes by said monitored vehicle for terminating said periodic energization of said pulse generating means of a first class.

11. Multi-lane traffic speed monitoring means comprising:

a pair of sensors comprising a start-timing sensor and a stop-timing sensor positioned apart a predetermined distance d in each lane of traffic, the pair of sensors in each lane constituting means for generating start-timing and stop-timing signals, respectively, in response to actuation of the sensors by passing vehicles;

a separate pulse generating means of a first class connected to each start-timing sensor and energizable in response to each actuation of the connected start-timing sensor to generate a delay-inducing signal of a first class having a predetermined duration in time;

a controlling means responsive to a given set of conditions consisting of the actuation of the start-timing sensor by a monitored vehicle in a given lane and the concurrent non-energization of the pulse generating means of said first class connected thereto for producing a cycle initiating signal;

computing means having a cycling state and a non-cycling state for computing the velocity of the monitored vehicle when in its cycling state;

said computing means being responsive to said cycle initiating signal to enter its cycling state and further responsive to the stop-timing signal generated by said stop-timing sensor in the said given lane to produce an output signal v representative of the velocity of said monitored vehicle;

each of the pulse generating means of said first class other than the one of said pulse generating means of said first class connected to the start-timing sensor in said given lane being responsive to said cycle initiating signal for emitting a delay-inducing signal of a second class for preventing further occurrence of said given set of conditions during said cycling state;

means responsive to the output signal v, when said signal v lies within predetermined values, for producing an output signal e; and

recording means responsive to said output signal e for recording the image of said monitored vehicle.

12. Multi-lane traffic speed monitoring means in accordance with claim 11 comprising:

pulse generating means of a second class and responsive to the signal e for generating a delay-inducing signal having a predetermined duration in time;

each of said pulse generating means of the first class being responsive to said delay-inducing signal produced by the pulse generating means of the second class for generating a delay-inducing signal.

13. Multi-lane traffic speed monitoring means in accordance with claim 12 comprising:

logic control means for sensing the lane in which the monitored vehicle is traveling and responsive to said output signal v for causing said recording means to optically track said monitored vehicle and to begin said optical tracking in a sequence wherein the image of said vehicle is recorded at a predetermined time after the optical tracking begins.

14. Multi-lane traffic monitoring means in accordance with claim 11 comprising:

logic control means for sensing the lane in which the monitored vehicle is traveling and responsivE to said output signal v for causing said recording means to optically track said monitored vehicle and to begin said optical tracking in a sequence wherein the image of said vehicle is recorded at a predetermined time after the optical tracking begins.

15. Multi-lane traffic speed monitoring means in accordance with claim 11 in which said computing means comprises:

logic means for sensing and responding to the expiration of a time interval of a predetermined length occurring between the initiation of said cycle initiating signal and the actuation of the stop-timing sensor by the monitored vehicle for periodically energizing said pulse generating means of said first class at a rate sufficient to maintain said pulse generating means of said first class in a continuously energized state;

said logic means being further responsive to actuation of said stop-timing sensor actuated by said monitored vehicle for terminating said periodic energization of said pulse generating means of said first class.

16. A traffic monitoring means comprising:

start-timing and stop-timing sensors positioned in a lane of traffic and spaced apart a predetermined distance for generating start-timing and stop-timing signals, respectively, in response to passing vehicles;

a first pulse generating means responsive to each actuation of said start-timing sensor for generating a first delay-inducing signal having a predetermined duration in time;

storage means for storing a first scalar quantity d representative of said predetermined distance;

control circuit means responsive to actuation, by a monitored vehicle, of said start-timing sensor while said first pulse generating means is de-energized for producing a computation initiating signal;

time measuring means energized in response to said computation initiating signal for measuring the time interval between said computation initiating signal and actuation of said stop-timing sensor and producing a second scalar quantity representative of said time interval;

computing means having a computation cycle and responsive to the generation of said second scalar quantity to divide said first scalar quantity d thereby to produce an output signal v which has a value representative of the average velocity of said monitored vehicle during said time interval;

means responsive to the output signal v, when said signal v lies within predetermined values, for producing an output signal e;

recording means responsive to said output signal e for recording the image of said monitored vehicle; and

tracking means responsive to the said output signal v and the value thereof for causing said recording means to optically track said monitored vehicle.

17. A traffic monitoring means in accordance with claim 16 and further comprising:

further pulse generating means responsive to the output signal e for generating a second delay-inducing signal having a predetermined duration in time, said first pulse generating means being responsive to said second delay-inducing signal to generate a third delay-inducing signal.

18. A traffic monitoring means in accordance with claim 16 and further comprising:

logic means for sensing and responding to the expiration of a time interval of a predetermined length occurring between the initiation of said computation initiating signal and the actuation of the stop-timing sensor by the monitored vehicle for periodically energizing said first pulse generating means at a rate sufficiently high to maintain said first pulse generating means in a continuously energized state and to inhibit the recording of an image of said monitored vehicle;

said logic means being further responsive to actuation of said stop-timing sensor by said monitored vehicle for terminating said periodic energization of said first pulse generating means.

19. A traffic monitoring means comprising:

a pair of start-timing and stop-timing sensors poSitioned in a traffic lane a predetermined distance d apart and actuated by a vehicle passing thereby to generate start-timing and stop-timing signals respectively;

a delay-signal producing means connected to receive each start-timing signal and responsive thereto for emitting a delay-inducing signal which is of a first class, has a predetermined duration of existence in time, and begins at a predetermined time subsequent to reception of the start-timing signal by the delay-signal producing means;

control means responsive to the concurrence of actuation of said start-timing sensor and to the non-emitting condition of said delay-signal producing means to provide a computation initiating signal;

said control means being responsive to said delay-inducing signal of said first class for preventing generation of an additional computation initiating signal by actuation of said start-timing means during the existence of said delay-inducing signal of said first class;

computing means responsive to said computation initiating signal and to the stop-timing signal from the subsequent actuation of said stop-timing sensor to produce a first output signal v representative of the velocity of the monitored vehicle;

logic means for producing a second output signal e if said output signal v lies within a predetermined range;

recording means responsive to said second output signal e for recording an image of said monitored vehicle; and

tracking means responsive to said output signal v for causing said recording means to optically track said monitored vehicle.

20. A traffic monitoring means in accordance with claim 19 and further comprising:

pulse generating means responsive to the output signal e for generating a delay-inducing signal of a second class and having a predetermined duration in time, said delay-signal producing means being responsive to said delay-inducing signal of the second class for generating a delay-inducing signal of a third class.

21. A traffic monitoring means in accordance with claim 19 and comprising:

logic means for sensing and responding to the expiration of a time interval of a predetermined length occurring between the initiation of said computation initiation signal and the subsequent actuation of said stop-timing sensor, actuation of the start-timing sensor of which lane has been responded to by the control means to provide the computation initiation signal, for periodically energizing said delay-signal producing means at a rate sufficient to maintain said delay-signal producing means in a continuously emitting state;

said logic means being further responsive to actuation of said stop-timing sensor by said monitored vehicle for terminating said periodic energization of said delay-signal producing means.

22. A traffic monitoring system for vehicles moving in a predetermined path of movement, said system including:

detector means for detecting vehicles moving in the predetermined path and providing an electric output which varies in accordance with the speed of movement of a vehicle moving in the said path;

control means operatively associated with said detector means responsive to the output of said detector means for providing a control output signal when the speed of a vehicle moving in said path exceeds a predetermined value, said control output signal varying in accordance with the speed of the vehicle;

camera means positioned adjacent said path for photographing the front end of a vehicle moving in said path after said detector means have produced said output after detecting the vehicle, said camera means having a light sensitive means on which images of the front ends of the vehicles moving in said predetermined path are projectable;

tracking means operatively associated with said camera means and responsive to said output signal of said control means for tracking the vehicle in accordance with its speed and for causing the image of a vehicle Moving in said predetermined path whose speed exceeds said predetermined value to be projected on the light sensitive means of the camera means without movement of said image on said light sensitive means during the period of operation of said camera means; and

means responsive to said control output signal for operating said camera means during the period of time said tracking means is tracking the movement of a vehicle whose speed exceeds said predetermined value.

23. The traffic monitoring system of claim 22, wherein said tracking means comprises a mirror and means for moving said mirror in accordance with said output signal of said control means for causing the image of the front end of the vehicle whose speed exceeds said predetermined value to be projected to said light sensitive means of said camera means.

24. The traffic monitoring system of claim 22, wherein said detector means comprises first and second sensors spaced apart a predetermined distance and operable successively by each vehicle moving in said path, the time period between successive operations of said first and second sensors varying in accordance with the speed of the vehicle.

25. The traffic monitoring system of claim 24, wherein said tracking means comprises a mirror and means for moving said mirror in accordance with said output signal of said control means for causing the image of the front end of the vehicle whose speed exceeds said predetermined value to be projected to said light sensitive means of said camera means.

26. A traffic monitoring system for vehicles moving a plurality of parallel, predetermined paths of movement, said system including:

separate detector means operatively associated with each of said paths for detecting vehicles moving in said paths and each providing an electric output which varies in accordance with the speed of movement of a vehicle moving in its associated path;

control means operatively associated with said detector means and responsive to the outputs of said detector means for providing a control output signal when the speed of a vehicle moving in any one of the paths exceeds a predetermined value, said control output signal varying in accordance with the speed of the vehicle;

camera means positioned adjacent said paths for photographing the driver and the front end of a vehicle moving in any one of said paths after the detector means associated with the path in which the vehicle is moving has provided an electric output responsive to the movement of the vehicle in the path, said camera means having a light sensitive means on which an image of the front end of a vehicle traveling in any one of said paths is projectable;

tracking means operatively associated with said camera means and responsive to the output signal of said control means for tracking a vehicle in accordance with its speed and for causing the image of a vehicle moving in one of the paths whose speed exceeds said predetermined value to be maintained on the light sensitive means of the camera means without movement of said image on said light sensitive means during the period of operation of said camera means; and

means responsive to said control output signal for operating said camera means during the period of time in which said tracking means is tracking the movement of a vehicle, in one of said paths, whose speed exceeds said predetermined value.

27. The traffic monitoring system of claim 26, wherein said tracking means comprises a mirror and means for moving said mirror in accordance with said output signal of said control means for causing the image of the front end of the vehicle whose speed exceeds said predetermined value to be projected to said light sensitive means of said camera means.

28. The traffic monitoring system of claim 26, wherein each of said detector means comprises first and second sensors spaced apart a predetermined distance and operable successively by each vehicle moving in the associated path.

29. The traffic monitoring System of claim 28, wherein said tracking means comprises a mirror and means for moving said mirror in accordance with said output signal of said control means for causing the image of the front end of the vehicle whose speed exceeds said predetermined value to be projected to said light sensitive means of said camera means.