System and method for traffic monitoring, speed determination, and traffic light violation detection and recording

• US 20050242306A1
• Filed: 04/29/2005
• Published: 11/03/2005
• Est. Priority Date: 04/29/2004
• Status: Active Grant

• Current Assignee: Optotraffic, LLC
• Original Assignee: Sigma Space Corp.
• Inventors: Seas, Antonios, Field, Christopher, Marzouk, Marzouk, Sirota, J. Marcos
• Granted Patent: US 7,616,293 B2
• Time in Patent Office: Days
• US Class Current: 250/559.380
• CPC Class Codes: G01V 8/20 using multiple transmitters or receivers
• CPC Class Codes: G08G 1/052 with provision for determining speed or overspeed speed measuring in general G01P

Abstract

A system of lasers and detectors to detect the presence of objects and determine their speed is disclosed. The system comprises of a pair of lasers and a pair of detectors focused through a single lens. An electronic board that accompanies the lasers and detectors is used to provide the logic and decision making mechanism. Data collected and processed by the system yields such information as whether an object is present, whether is stationary or is moving, and subsequent speed information. The described system is also capable if desired of providing additional information concerning the characteristics of the moving object such as its profile and length, and indication of a traffic violation.

Claims

1. A detector for sensing an object on a surface, comprising:

a first laser emitter focused through a single lens on said surface;

a first controller to control radiation emission from said first laser emitter;

a first detector that receives at least a portion of radiation emitted from said first laser emitter and reflected or scattered back through said single lens and that provides a signal upon receiving said radiation; and

a processor operationally attached to said first controller and said first detector that analyzes the received signal and provides an output indicative the range to an object on said surface.

2. The detector according to claim 1, wherein said first laser emitter comprises a diode laser.

3. The detector according to claim 1, further comprising:

a mirror with at least one aperture to enable radiation from said first laser emitter to pass therethrough, said mirror being aligned to reflect radiation reflected or scattered back through said lens to said first detector.

4. The detector according to claim 3, wherein the size of the at least one aperture in said mirror is sized and configured such that only eye-safe radiation levels are allowed to pass therethrough.

5. The detector according to claim 3, further comprising:

a second laser emitter focused through said single lens on the surface;

a second controller to control radiation emission from said second laser emitter; and

a second detector that receives at least a portion of radiation emitted from said second laser emitter and reflected or scattered back through said single lens and that provides a signal upon receiving said radiation;

wherein

said processor is operationally attached to said first and second controller and said first and second detector, and analyzes the received signals and provides an output indicative of at least one selected feature of an object on said surface.

6. The detector according to claim 5, wherein said first and second laser emitters comprise diode lasers.

7. The detector according to claim 6, wherein said first and second laser emitters are focused in narrow rectangular spots on said surface with a long side of said rectangular spot being aligned perpendicular to a travel path of an object on said surface.

8. A system for sensing an object moving along a path and recording information about said object, said system comprising:

a first laser emitter and a second laser emitter focused through a single lens on a surface of said path;

a first controller and a second controller to control radiation emission from said first and second laser emitters;

a first detector and a second detector that receive at least a portion of radiation emitted from said first and second laser and reflected back through said single lens and that provide a signal upon receiving said radiation;

a processor operationally attached to said first and second controller and said first and second detector that analyzes the received signal and provides an output; and

a recording device that receives output from said processor and documents information about said object.

9. The system according to claim 8, wherein said first and second laser emitters comprise diode lasers.

10. The system according to claim 8, further comprising:

a mirror with at least one aperture to enable radiation from said first and second laser emitters to pass therethrough, said mirror being aligned to reflect radiation reflected back through said lens to said first and second detectors.

11. The system according to claim 10, wherein the size of the at least one aperture in said mirror is sized and configured such that only eye-safe radiation levels are allowed to pass therethrough.

12. The system according to claim 8, said processor further comprising:

at least one time delay counter to measure the time from radiation transmission by a laser emitter to radiation detection by its detector.

13. The system according to claim 12, wherein said processor determines if an object is present on said path.

14. The system according to claim 13, wherein said processor provides output to said recording device to determine a profile of said object.

15. The system according to claim 12, wherein said first laser emitter and said second laser emitter are focused on different points on said surface and wherein the points are separated by a known distance.

16. The detector according to claim 15, wherein said first and second laser emitters are focused in narrow rectangular spots on said surface with a long side of said rectangular spot being aligned perpendicular to a travel path of an object on said surface.

17. The system according to claim 15, wherein said processor calculates the speed of said object based upon time delay measured by said at least one time delay counter.

18. The system according to claim 17, said recording device comprising a camera that takes a picture of said object when said calculated speed exceeds a predetermined threshold.

19. The system according to claim 17, wherein said system is used to detect a traffic violation, said system further comprising an input to said processor indicating the status of a traffic control signal, and

wherein said recording device comprises a camera that takes a picture of said object when said calculated speed exceeds a predetermined threshold corresponding to a speed that it is unlikely that the object can stop before a violation occurs.

20. A method of determining speed of an object along a path, comprising:

providing a first laser emitter and a second laser emitter focused through a single lens on a surface of said path;

controlling radiation emission from said first and second laser emitters;

detecting at least a portion of radiation emitted from said first and second laser and reflected back through said single lens and providing a signal upon receiving said radiation;

processing said signal to detect the presence of an object on said path; and

displaying an output indicating the presence of said object if detected.

21. The method according to claim 20, wherein said first and second laser emitters comprise diode lasers.

22. The method according to claim 21, wherein said first and second laser emitters are focused in narrow rectangular spots on said surface with a long side of said rectangular spot being aligned perpendicular to a travel path of an object on said surface.

23. The method according to claim 20, said providing step further comprising:

providing a mirror with at least one aperture to enable radiation form said first and second laser emitters to pass therethrough, said mirror being aligned to reflect radiation reflected back through said single lens to a first detector and a second detector.

24. The method according to claim 23, wherein the size of the at least one aperture in said mirror is sized and configured such that only eye-safe radiation levels are allowed to pass therethrough.

25. The method according to claim 20, wherein said signal upon receiving said radiation comprises a time delay.

26. The method according to claim 25, said processing step further comprising:

calculating the height of the object if the time delay for receiving said radiation is less than the expected time delay if no object is present.

27. The method according to claim 25, wherein said first laser emitter and said second laser emitter are focused on different points on said surface and wherein the points are separated by a known distance, said processing step further comprising:

detecting said object with said first laser emitter;

detecting said object with said second laser emitter;

measuring the time delay between detecting by said first laser emitter and detecting by said second laser emitter; and

calculating the velocity of said object based on the front of said object by dividing the known distance between the focus points by the time delay between detecting by said first laser emitter and detecting by said second laser emitter.

28. The method according to claim 27, said processing step further comprising:

ceasing detecting said object with said first laser emitter;

ceasing detecting said object with said second laser emitter;

measuring the time delay between ceasing detecting by said first laser emitter and ceasing detecting by said second laser emitter; and

calculating the velocity of said object based on the back of said object by dividing the known distance between the focus points by the time delay between ceasing detecting by said first laser emitter and ceasing detecting by said second laser emitter.

29. The method according to claim 28, further comprising the steps of:

calculating the acceleration of said object by determining the change in velocity between the front of said object and the back of said object and dividing by the change in time.

30. The method according to claim 28, further comprising the steps of:

calculating the average velocity of the object.

31. The method according to claim 29, further comprising the steps of:

calculating the average acceleration of the object.

32. The method according to claim 28, further comprising the steps of:

providing an input indicating the status of a traffic control signal;

if the traffic control signal indicates that the object should stop and the velocity of said object is such that it is unlikely that the object can stop before a violation occurs, taking a picture of said object;

calculating the amount of time for said object to travel a predetermined distance; and

taking at least one more picture of said object.