Aperture monitoring system and method

• US 20020179822A1
• Filed: 07/09/2002
• Published: 12/05/2002
• Est. Priority Date: 05/21/2001
• Status: Active Grant

• Current Assignee: American Vehicular Sciences LLC (Acacia Research Corporation)
• Original Assignee: Automotive Technologies International Incorporated
• Inventors: Breed, David S., Johnson, Wendell C., DuVall, Wilbur E.
• Granted Patent: US 6,875,976 B2
• Time in Patent Office: Days
• US Class Current: 250/221
• CPC Class Codes: B60J 7/0573 power driven arrangements, e.g. electrical
• CPC Class Codes: G01S 15/04 Systems determining presence of a target
• CPC Class Codes: G01S 17/04 Systems determining the presence of a target

Abstract

System and method for detecting the presence of an object in an aperture in which for modulated electromagnetic waves are directed from an edge of a frame defining the aperture and electromagnetic waves reflected from an opposite edge of the frame are received at substantially the same location. The phase change between the modulated electromagnetic waves and the reflected electromagnetic waves is measured wherein the presence of an obstacle in the aperture causes a variation in the phase change from a situation where an obstacle is not present. The system and method can be used in vehicles to determine the presence of obstacles in the path of a closing window, door, trunk lid, convertible top, or sunroof.

Claims

1. A system for detecting the presence of an object in an aperture, comprising:

electromagnetic wave emitting means for emitting modulated electromagnetic waves and directing the modulated electromagnetic waves from at least one edge of a frame defining the aperture;

receiving means for receiving reflected electromagnetic waves; and

means for measuring a phase change between the modulated electromagnetic waves and the reflected electromagnetic waves, whereby the presence of an obstacle in the aperture causes a variation in the phase change from the phase change in a situation where an obstacle is not present in the aperture.

2. The system of claim 1, wherein said receiving means comprise a linear CMOS array.

3. The system of claim 1, wherein said receiving means comprise a one-dimensional camera.

4. The system of claim 1, wherein said electromagnetic wave emitting means comprise at least one light emitting diode.

5. The system of claim 1, wherein said electromagnetic wave emitting means comprise a plurality of electromagnetic wave emitting diodes.

6. The system of claim 1, wherein said electromagnetic wave emitting means comprise a scanning laser system.

7. The system of claim 6, wherein said receiving means comprise a single photo diode.

8. The system of claim 1, wherein said electromagnetic wave emitting means are structured and arranged as modulated electromagnetic waves with a modulation wavelength between about 1 foot and 20 feet.

9. The system of claim 1, wherein said electromagnetic wave emitting means are arranged to illuminate at least a portion of said frame defining the aperture.

10. The system of claim 1, wherein said electromagnetic wave emitting means are structured and arranged to direct the electromagnetic waves into a plane substantially parallel to a plane in which the aperture is situated.

11. The system of claim 1, wherein said electromagnetic wave emitting means comprise a plurality of segments of electromagnetic wave emitting elements arranged in said frame defining the aperture.

12. The system of claim 1, wherein said receiving means comprise a lens.

13. The system of claim 1, wherein at least one of said electromagnetic wave emitting means and said receiving means comprise a mirror.

14. The system of claim 1, wherein said electromagnetic wave emitting means and said receiving means are collocated in said frame defining the aperture.

16. The method of claim 15, further comprising the step of obtaining a reference phase change or reference phase change function by measuring the phase change between the modulated electromagnetic waves and the reflected electromagnetic waves when an obstacle is known not to be present in the aperture.

17. The method of claim 16, wherein the step of detecting the presence of an obstacle in the aperture comprises the step of comparing the reference phase change or reference phase change function to the measured change whereby a difference between the measured phase change and the reference phase change or reference phase change function is indicative of the presence of an object in the aperture.

18. The method of claim 15, wherein the means for receiving reflected electromagnetic waves comprise a linear CMOS array arranged in the frame of the aperture.

19. The method of claim 15, wherein the means for receiving reflected electromagnetic waves comprise a one-dimensional camera.

20. The method of claim 15, wherein the step of directing illuminating electromagnetic waves comprises the step of arranging at least one electromagnetic wave emitting diode in the frame of the aperture.

21. The method of claim 15, wherein the step of directing illuminating electromagnetic wave comprises the step of arranging a plurality of electromagnetic wave emitting diodes in the frame of the aperture.

22. The method of claim 15, wherein the step of directing illuminating electromagnetic waves comprises the step of directing a laser beam and moving the laser beam to scan across at least a portion of the aperture.

23. The method of claim 22, wherein the means for receiving the reflected electromagnetic waves comprise a single photo diode.

24. The method of claim 15, wherein the step of modulating the illuminating electromagnetic wave comprises the step of modulating the electromagnetic waves with a modulation wavelength between about 1 foot and 20 feet.

26. The system of claim 25, wherein said electromagnetic pulse emitting means comprise at least one light emitting diode.

27. The system of claim 25, wherein said electromagnetic pulse emitting means are structured and arranged to direct the electromagnetic pulse into a plane substantially parallel to a plane in which the aperture is situated.

28. The system of claim 25, wherein said electromagnetic pulse emitting means and said receiving means are collocated in said frame defining the aperture.

30. The method of claim 29, wherein the coded signal is an amplitude modulated carrier wave.

31. The method of claim 29, wherein the coded signal is a phase modulated carrier wave.

32. The method of claim 29, wherein the coded signal is an individual pulse.

33. The method of claim 29, further comprising the step of obtaining a reference time of flight or reference time of flight function by measuring the time of flight between the transmitted coded signal and the received coded signal when an obstacle is known not to be present in the aperture.

34. The method of claim 33, wherein the step of detecting the presence of an obstacle in the aperture comprises the step of comparing the reference time of flight or reference time of flight function to the measured time of flight whereby a difference between the measured time of flight and the reference time of flight or reference time of flight function is indicative of the presence of an object in the aperture.

35. The method of claim 29, wherein the means for receiving the coded signal comprise a linear CMOS array arranged in the frame of the aperture.

36. The method of claim 29, wherein the means for receiving the coded signal comprise a one-dimensional camera.

37. The method of claim 29, wherein the step of transmitting the coded signal comprises the step of arranging at least one electromagnetic wave emitting diode in the frame of the aperture.

38. The method of claim 29, wherein the step of transmitting the coded signal comprises the step of arranging a plurality of electromagnetic wave emitting diodes in the frame of the aperture.

39. The method of claim 29, wherein the step of transmitting the coded signal comprises the step of directing a laser beam and moving the laser beam to scan across at least a portion of the aperture.

40. The method of claim 39, wherein the means for receiving the coded signal comprise a single photo diode.

15. A method for detecting the presence of an object in an aperture, comprising the steps of:

directing illuminating electromagnetic waves toward at least a portion of a frame defining the aperture;

modulating the illuminating electromagnetic waves;

providing means for receiving electromagnetic waves reflected from the illuminated portion of the frame; and

detecting the presence of an obstacle in the aperture by measuring a phase change between the modulated electromagnetic waves and the reflected electromagnetic waves, whereby the presence of an obstacle in the aperture causes a variation in the phase change from a situation where an obstacle is not present.

25. A system for detecting the presence of an object in an aperture, comprising:

electromagnetic pulse emitting means for emitting an electromagnetic pulse and directing the electromagnetic pulse from at least one edge of a frame defining the aperture;

receiving means for receiving reflected electromagnetic waves from the electromagnetic pulse; and

means for measuring a time of flight between the emission of the electromagnetic pulse and the reception of the reflected electromagnetic waves, whereby the presence of an obstacle in the aperture causes a variation in the time of flight from a reference time of flight in a situation where an obstacle is not present in the aperture.

29. A method for detecting the presence of an object in an aperture, comprising the steps of:

transmitting a coded signal toward at least a portion of a frame defining the aperture;

providing means for receiving the coded signal reflected from the portion of the frame; and

detecting the presence of an obstacle in the aperture by measuring the time of flight between the transmission of the coded signal and the reception of the coded signal using correlation, whereby the presence of an obstacle in the aperture causes a variation in the time of flight from a situation where an obstacle is not present.