Aperture monitoring system and method

• US 6,875,976 B2
• Filed: 07/09/2002
• Issued: 04/05/2005
• Est. Priority Date: 05/21/2001
• Status: Expired due to Fees

• 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.
• Primary Examiner(s): Luu, Thanh X.
• Assistant Examiner(s): Sohn, Seung C.
• Application Number:
  US10/191,692
• Publication Number:
  US 20020179822A1
• Time in Patent Office: 1,001 Days
• Field of Search: 250/221, 250/222.1, 340555-557, 340/565, 340/541, 340/542.2, 340/542.3, 340/545.7, 340/545.1, 318264-266, 318/466, 318/565
• 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

measuring means for measuring a reference phase change between the modulated electromagnetic waves and the reflected electromagnetic waves, when it is known no object is present in the aperture and for measuring an operative phase change when an object is potentially present in the aperture at a different time than when the reference phase change is measured;

the operative phase change being compared to the reference phase change to determine whether there is a difference between the operative phase change and the reference phase change, whereby a difference between the reference phase change and the operative phase change is indicative of the presence of an object 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 comprises 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.

15. The system of claim 1, wherein said measuring means include a memory unit for storing the reference phase change.

16. The system of claim 1, wherein the reference phase change is expressed as a function of distance along a side of the frame defining the aperture.

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

determining a reference phase change by;

directing illuminating electromagnetic waves toward at least a portion of a frame defining the aperture when an obstacle is known not to be present in the aperture,

modulating the illuminating electromagnetic waves,

receiving electromagnetic waves reflected from the illuminated portion of the frame,

measuring a phase change between the modulated electromagnetic waves and the received electromagnetic waves, and

storing the measured phase change as the reference phase change;

determining an operative phase change when an object is potentially present in the aperture by;

directing illuminating electromagnetic waves toward the same portion of the frame defining the aperture,

modulating the illuminating electromagnetic waves,

receiving electromagnetic waves reflected from the illuminated portion of the frame, and

measuring a phase change between the modulated electromagnetic waves and the received electromagnetic waves for use as the operative phase change; and

detecting the presence of an obstacle in the aperture by comparing the operative phase change with the reference phase change to determine whether there is a difference between the operative phase change and the reference phase change, whereby a difference between the reference phase change and the operative phase change is indicative of the presence of an object in the aperture.

18. The method of claim 17, wherein the steps of receiving reflected electromagnetic waves comprise arranging a linear CMOS array in the frame defining the aperture.

19. The method of claim 17, wherein the steps of receiving reflected electromagnetic waves comprise arranging a one-dimensional camera in the frame defining the aperture.

20. The method of claim 17, wherein the steps of directing illuminating electromagnetic waves comprise the step of arranging at least one electromagnetic wave emitting diode in the frame defining the aperture.

21. The method of claim 17, wherein the steps of directing illuminating electromagnetic waves comprise the step of arranging a plurality of electromagnetic wave emitting diodes in the frame defining the aperture.

22. The method of claim 17, wherein the steps of directing illuminating electromagnetic waves comprise the steps 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 steps of receiving the reflected electromagnetic waves comprise arranging a single photo diode in the frame defining the aperture.

24. The method of claim 17, wherein the steps of modulating the illuminating electromagnetic waves comprise modulating the electromagnetic waves with a modulation wavelength between about 1 foot and 20 feet.

25. The method of claim 17, further comprising the step of storing the reference phase change such that the operative phase change is measured at a subsequent time and compared to the stored reference phase change.

26. The method of claim 17, wherein the step of determining a reference phase change further comprises deriving a reference phase change function which expresses the reference phase change as a function of distance along a side of the frame defining the aperture, the step of detecting the presence of an object in the aperture comprises comparing the operative phase change measured along the side of the frame defining the aperture with the reference phase change function.

27. 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

measuring means for measuring a reference phase change between the modulated electromagnetic waves and the reflected electromagnetic waves when it is known no object is present in the aperture and for measuring an operative phase change when an object is potentially present in the aperture at a different time than when the reference phase change is measured, the reference phase change being expressed as a function of distance along a side of the frame defining the aperture,

the operative phase change being compared to the reference phase change to determine whether there is a difference between the operative phase change and the reference phase change, whereby a difference between the reference phase change and the operative phase change is indicative of the presence of an object in the aperture.

28. The system of claim 27, wherein said receiving means comprise a linear CMOS array.

29. The system of claim 27, wherein said receiving means comprise a one-dimensional camera.

30. The system of claim 27, wherein said electromagnetic wave emitting means comprise at least one light emitting diode.

31. The system of claim 27, wherein said electromagnetic wave emitting means comprise a plurality of electromagnetic wave emitting diodes.

32. The system of claim 27, wherein said electromagnetic wave emitting means comprise a scanning laser system.

33. The system of claim 32, wherein said receiving means comprise a single photo diode.

34. The system of claim 27, 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.

35. The system of claim 27, wherein said electromagnetic wave emitting means are arranged to illuminate at least a portion of said frame defining the aperture.

36. The system of claim 27, 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.

37. The system of claim 27, wherein said electromagnetic wave emitting means comprise a plurality of segments of electromagnetic wave emitting elements arranged in said frame defining the aperture.

38. The system of claim 27, wherein at least one of said electromagnetic wave emitting means and said receiving means comprise a mirror.

39. The system of claim 27, wherein said electromagnetic wave emitting means and said receiving means are collocated in said frame defining the aperture.

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

determining a reference phase change function by;

directing illuminating electromagnetic waves toward at least a portion of a frame defining the aperture when an obstacle is known not to be present in the aperture,

modulating the illuminating electromagnetic waves,

receiving electromagnetic waves reflected from the illuminated portion of the frame;

measuring a phase change between the modulated electromagnetic waves and the received electromagnetic waves, and

storing the measured phase change as a function of distance along a side of the frame defining the aperture for use as the reference phase change function;

determining an operative phase change along the side of the frame defining the aperture when an object is potentially present in the aperture by;

directing illuminating electromagnetic waves toward the same portion of the frame defining the aperture,

modulating the illuminating electromagnetic waves,

receiving electromagnetic waves reflected from the illuminated portion of the frame, and

measuring a phase change between the modulated electromagnetic waves and the received electromagnetic waves for use as the operative phase change; and

detecting the presence of an obstacle in the aperture by comparing the operative phase change with the reference phase change function to determine whether there is a difference between the operative phase change and the reference phase change function, whereby a difference between the reference phase change function and the operative phase change is indicative of the presence of an object in the aperture.

41. 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

a common measuring device arranged to measure a phase change between the modulated electromagnetic waves and the reflected electromagnetic waves when it is known no object is present in the aperture for use as a reference phase change and to measure an operative phase change when an object is potentially present in the aperture at a different time than when the reference phase change is measured,

the operative phase change being compared to the reference phase change to determine whether there is a difference between the operative phase change and the reference phase change, whereby a difference between the reference phase change and the operative phase change is indicative of the presence of an object in the aperture.

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

determining a reference phase change between emitted, modulated electromagnetic waves and received electromagnetic waves reflected by a frame defining the aperture when an obstacle is known not to be present in the aperture;

determining an operative phase change between emitted, modulated electromagnetic waves and received electromagnetic waves when an object is potentially present in the aperture; and

detecting the presence of the object in the aperture by comparing the operative phase change with the reference phase change to determine whether there is a difference between the operative phase change and the reference phase change, whereby a difference between the reference phase change and the operative phase change is indicative of the presence of the object in the aperture.