Method and apparatus for measuring speed

• US 20040239528A1
• Filed: 06/02/2004
• Published: 12/02/2004
• Est. Priority Date: 07/12/2001
• Status: Abandoned Application

• Current Assignee: Andrew Luscombe
• Original Assignee: Andrew Luscombe
• Inventors: Luscombe, Andrew
• Application Number:
  US10/483,713
• Publication Number:
  US 20040239528A1
• Time in Patent Office: Days
• US Class Current: 340/942
• CPC Class Codes: G01P 3/68 using optical means, i.e. using infrared, visible, or ultraviolet light G01P3/80 takes precedence ; by reflection of waves G01S17/58
• CPC Class Codes: G01S 17/06 Systems determining position data of a target
• CPC Class Codes: G01S 17/50 Systems of measurement based on relative movement of target
• CPC Class Codes: G08G 1/052 with provision for determining speed or overspeed speed measuring in general G01P

Abstract

The invention provides a method and apparatus for monitoring a moving object, the method comprising: emitting electromagnetic radiation so that the object passes through the electromagnetic radiation; detecting a plurality of reflection events, each comprising a reflection of the electromagnetic radiation from the object; determining a direction of each of the reflection events from the direction of emission of the electromagnetic radiation or from the direction of detection of the respective reflection event; and determining the relative timing of the reflection events; wherein information pertaining to the object can be determined, the information comprising any one or more of a speed, a location and a direction of the object.

Claims

1. A method of monitoring a moving object having a velocity, comprising:

emitting electromagnetic radiation so that said object passes through said electromagnetic radiation;

detecting a plurality of reflection events, each comprising a reflection of said electromagnetic radiation from said object;

determining a direction of each of said reflection events from the direction of emission of said electromagnetic radiation or from the direction of detection of said respective reflection event; and

determining the relative timing of said reflection events;

wherein information pertaining to said object can be determined, said information comprising any one or more of a speed, a location and a direction of said object.

2. A method as claimed in claim 1, including deriving further information from said information, such as that the object has indeed passed into or through said electromagnetic radiation.

3. A method as claimed in claim 1, wherein said electromagnetic radiation comprises a plurality of beams of electromagnetic radiation each having a known emission direction, wherein the direction of a reflection event is determined from said known emission directions.

4. A method as claimed in claim 3, wherein said method includes emitting three or more beams of electromagnetic radiation, and said velocity has a respective component parallel to each of said beams.

5. A method as claimed in claim 3, wherein at least one pair of said beams are non-parallel with respect to each other.

6. A method as claimed in claim 3, wherein each of said beams is a spatially dispersing beam in a first plane and relatively narrow in a second plane perpendicular to said first plane.

7. A method as claimed in claim 3, wherein each of said beams is a composite beam comprising multiple sub-beams.

8. A method as claimed in claim 1, including detecting said reflection events by means of a plurality of detectors each having a known detection direction, wherein the direction of a reflection event is determined from said known detection directions.

9. A method as claimed in claim 8, including detecting said reflection events by means of three or more detectors each having a known detection direction.

10. A method as claimed in claim 9, wherein each of said plurality of detectors has a detection region that is relatively broad in a first plane and relatively narrow in a second plane perpendicular to said first plane.

11. A method as claimed in claim 10, wherein said first plane is substantially upright.

12. A method as claimed in claim 1, wherein said electromagnetic radiation is infrared radiation or visible light or ultraviolet light.

13. A method as claimed in claim 1, including modulating said electromagnetic radiation so that reflected electromagnetic radiation detected from said reflection events is correspondingly modulated, and discriminating between said modulated reflected electromagnetic radiation and background or other undesired electromagnetic radiation.

14. A method as claimed in claim 1, including DC filtering reflected electromagnetic radiation detected from said reflection events or a signal corresponding thereto, to eliminate unmodulated and therefore undesired detected electromagnetic radiation.

15. A method as claimed in claim 1, including detecting one or more of said reflection events in the form of at least one temporal spectrum of reflected electromagnetic radiation intensity.

16. A method as claimed in claim 1, including emitting said electromagnetic radiation and detecting said plurality of reflection events from respective locations of close proximity.

17. A method as claimed in claim 1, wherein said electromagnetic radiation is emitted from one or more sources of electromagnetic radiation, and said method includes detecting said reflection events by-means of one or more detectors each having a known detection direction, wherein each of said one or more sources is located in close proximity to at least one of said detectors.

18. A method as claimed in claim 17, including detecting reflection events due to reflection of electromagnetic radiation from a respective one of said one or more sources by means of a respective one of said detectors, wherein said respective one of said one or more sources and said respective one of said detectors are in close proximity.

19. A method as claimed in claim 17, including detecting said reflection events, by means of three or more detectors.

20. A method for measuring the speed of a moving motor vehicle, including the method of claim 1.

40. A method as claimed in claim 6, wherein said first plane is substantially upright.

41. A method as claimed in claim 1, including tracking said object by determining a plurality of values, each at a different time, of the speed of said object or of the location of said object or of both the speed and location of said object.

42. A method as claimed in claim 6, wherein said beams do not all intersect along a single line.

43. A method as claimed in claim 6, including employing further beams in addition to the minimum number of beams necessary to determine said information, whereby additional information provided by said further beams is used for error checking or to improve reliability or to track said object.

21. An apparatus for monitoring an object moving with a velocity along a path, comprising:

an electromagnetic radiation emitter for emitting electromagnetic radiation into said path;

an electromagnetic radiation detector for detecting a plurality of reflection events, each comprising a reflection of said electromagnetic radiation from said object, and outputting an output signal in response thereto; and

computation means for receiving said output signal, determining the relative timing of said reflection events and associating with each of said reflection events a direction derived from the direction of emission of said electromagnetic radiation or from the respective direction of detection of said respective reflection event.

22. An apparatus as claimed in claim 21, wherein said computation means is operable to determine information from at least the relative timing of said reflection events and said directions thereof, said information comprising any one or more of a speed, a location and a direction of said object.

23. An apparatus as claimed in claim 21, wherein said computation means is operable to derive further information from said information, such as that the object as indeed passed into or through said electromagnetic radiation.

24. An apparatus as claimed in claim 21, wherein said emitter includes a plurality of electromagnetic radiation sources, each for emitting electromagnetic radiation having a known emission direction, wherein the direction of a reflection event is determinable from said known emission directions.

25. An apparatus as claimed in claim 24, wherein said apparatus includes three or more electromagnetic radiation sources, and said velocity has a respective component parallel to each of said emission directions.

26. An apparatus as claimed in claim 24, wherein at least one pair of said emission directions are non-parallel with respect to each other.

27. An apparatus as claimed in claim 24, wherein each of said sources emits a spatially dispersing beam in a first plane and relatively narrow in a second plane perpendicular to said first plane.

28. An apparatus as claimed in claim 27, wherein said first plane is substantially upright.

29. An apparatus as claimed in claim 21, wherein said electromagnetic radiation detector comprises a plurality of photodetectors each having a known detection direction, wherein the direction of a reflection event is determinable from said known detection directions.

30. An apparatus as claimed in claim 29, wherein said electromagnetic radiation detector comprises three of more photodetectors each having a known detection direction.

32. An apparatus as claimed in claim 21, including at least one modulator for modulating said electromagnetic radiation so that said reflected electromagnetic radiation is correspondingly modulated, and a discriminator for discriminating between said modulated reflected electromagnetic radiation and background or other undesired electromagnetic radiation.

33. An apparatus as claimed in claim 21, including at least one DC filter for filtering said reflected electromagnetic radiation or a signal corresponding thereto, to eliminate unmodulated and therefore undesired detected electromagnetic radiation.

34. An apparatus as claimed in claim 21, wherein said apparatus is operable to detect one or more of said reflection events in the form of at least one temporal spectrum of reflected electromagnetic radiation intensity.

35. An apparatus as claimed in claim 21, wherein said emitter and said detector are located so that said reflection events are detected at respective locations in close proximity to where said electromagnetic radiation is emitted.

36. An apparatus as claimed in claim 21, wherein said emitter comprises one or more sources of electromagnetic radiation, and said detector comprises one or more photodetectors each having a known detection direction, wherein each of said one or more sources is located in close proximity to at least one of said photodetectors.

37. An apparatus as claimed in claim 36, wherein said apparatus is configured to detect reflection events due to reflection of electromagnetic radiation from a respective one of said one or more sources by means of a respective one of said photodetectors, wherein said respective one of said one or more sources and said respective one of said photodetectors are in close proximity.

38. An apparatus as claimed in claim 35, wherein said detector comprises three or more photodetectors.

39. An apparatus for measuring the speed of a moving motor vehicle, including the apparatus as claimed in claim 21.

31. An apparatus as claimed in clam 29, wherein each of said plurality of photodetectors has a detection region that is relatively broad in a first plane and relatively narrow in a second plane perpendicular to said first plane.