Vehicle compartment occupancy detection system

• US 6,762,676 B2
• Filed: 12/10/2002
• Issued: 07/13/2004
• Est. Priority Date: 09/26/1996
• Status: Expired due to Fees

• Current Assignee: Donnelly Corporation (Magna International Incorporated)
• Original Assignee: Donnelly Corporation (Magna International Incorporated)
• Inventors: Agrawal, Anoop, McCarthy, Kevin, Teowee, Gimtong
• Primary Examiner(s): TONG, NINA C
• Application Number:
  US10/315,706
• Publication Number:
  US 20030090371A1
• Time in Patent Office: 581 Days
• Field of Search: 340/426.1, 340/429, 340/426.26, 340/426.29, 340/425.5, 340/430, 340/555, 340/556, 340/567, 340/573.1, 340/541, 340/565, 340/942, 307/10.2, 307/10.3, 307/10.4, 307/10.5, 180/167, 180/169, 180/287, 250/342, 250/353, 250/338.3, 250/DIG.1
• US Class Current: 340/426.1
• CPC Class Codes: B60R 2325/304 Boats
• CPC Class Codes: B60R 25/1004 Alarm systems characterised by the type of sensor, e.g. current sensing means using door lock sensors B60R25/1001

Abstract

A system is provided for detecting the presence of a human in a compartment of a vehicle that comprises a pyroelectric sensor and a control coupled to the pyroelectric sensor. The pyroelectric sensor comprises a first sensing element and a second sensing element. The first sensing element is arranged in an opposed electrical connection with respect to the second sensing element whereby infrared radiation from a human moving within the compartment is selectively detected by one of the first sensing element and the second sensing element, thereby producing an output signal of the pyroelectric sensor. This output signal is received by the control, and the control generates a control signal indicative of detection of a human within the compartment.

Claims

1. A system for detecting the presence of a human in a compartment of a vehicle comprising:

a pyroelectric sensor disposed at a surface of the compartment and a control coupled to said pyroelectric sensor;

said pyroelectric sensor comprising a first sensing element and a second sensing element, said first sensing element arranged in an opposed electrical connection with respect to said second sensing element whereby infrared radiation from a human moving within the compartment is differentially detected by said first sensing element and said second sensing element, and ambient thermal radiation is commonly detected by said first sensing element and said second sensing element, thereby producing an output signal with reduced sensitivity to ambient thermal radiation; and

said output signal being received by said control, said control generating a control signal indicative of detection of a human within the compartment; and

said first sensing element and said second sensing element being thermally isolated from the surface.

2. A system according to claim 1, wherein a radiation filter element is disposed in front of said pyroelectric sensor.

3. A system according to claim 2, wherein said filter element comprises at least one of Ge and Si.

4. A system according to claim 2, wherein said filter element comprises ZnS.

5. A system according to claim 2, wherein said filter element comprises Polyolefin.

6. A system according to claim 2, wherein said filter element preferentially passes radiation having wavelength between approximately 8 and 14 microns.

7. A system according to claim 2, wherein said pyroelectric sensor and said filter element are provided as a module.

8. A system according to claim 1, wherein said control comprises an electronic band-pass filter.

9. A system according to claim 8, wherein said electronic band-pass filter passes frequencies greater than 0.1 Hz.

10. A system according to claim 8, wherein said electronic band-pass filter passes frequencies greater than 0.1 Hz and less than 10 Hz.

11. A system according to claim 8, wherein said electronic band-pass filter passes frequencies greater than 0.5 Hz and less than 10 Hz.

12. A system according to claim 8, wherein said electronic band-pass filter passes frequencies greater than 1 Hz and less than 5 Hz.

13. A system according to claim 1, wherein said control resolves movement of a human moving at a distance of within about 1 to 5 meters of said pyroelectric sensor.

14. A system according to claim 1, wherein said control resolves movement of a human moving at a frequency of approximately 5 Hz.

15. A system according to claim 1, wherein said system has a power consumption of less than 1 Watt when connected to vehicle battery power and when the vehicle is in the parked state.

16. A system according to claim 1, wherein said system has a power consumption of less than 0.02 Watt when connected to vehicle battery power and when the vehicle is in the parked state.

17. A system according to claim 1, further comprising a lens, said lens focusing incident radiation onto said pyroelectric sensor.

18. A system according to claim 17, wherein said lens comprises a material that transmits radiation in approximately the 8 to 14 micron wavelength range.

19. A system according to claim 17, wherein said lens blocks radiation having a wavelength of approximately 0.3 to 3 microns.

20. A system according to claim 17, wherein said lens comprises a material comprising at least one of Ge, Si, ZnS, CdS and a polyolefin.

21. A system according to claim 17, wherein said lens comprises a polyolefin material.

22. A system according to claim 17, wherein said lens comprises a material including at least one of a polypropylene material, a polyethylene material and a polymethylpentene material, or a copolymer thereof.

23. A system according to claim 17, wherein said lens comprises at least one of a fish eye lens, a diffractive optic lens, a wide angle lens and a Fresnel lens.

24. A system according to claim 17, wherein said lens comprises a plastic lens.

25. A system according to claim 1, wherein said system consumes a current of less than approximately 5.0 mA when operating under vehicle battery power.

26. A system according to claim 1, wherein said system consumes a current of less than approximately 1.5 mA when operating under vehicle battery power.

27. A system according to claim 1, wherein said compartment comprises an interior compartment of the vehicle.

28. A system according to claim 1, wherein said control comprises an application specific integrated circuit.

29. A system according to claim 1, wherein said opposed first and second sensing elements are arranged in a parallel opposed connection.

30. A system according to claim 1, wherein said opposed first and second sensing elements are arranged in a series opposed connection.

31. A system according to claim 1, wherein said compartment comprises a trunk compartment of the vehicle.

32. A system for detecting the presence of a human in a compartment of a vehicle comprising:

a pyroelectric sensor disposed at a surface of the compartment and a control coupled to said pyroelectric sensor;

said pyroelectric sensor comprising a first sensing element and a second sensing element, said first sensing element arranged in an opposed electrical connection with respect to said second sensing element whereby infrared radiation from a human moving within the compartment is differentially detected by said first sensing element and said second sensing element, and ambient thermal radiation is commonly detected by said first sensing element and said second sensing element, thereby producing an output signal with reduced sensitivity to ambient thermal radiation;

wherein a radiation filter element is disposed in front of said pyroelectric sensor;

wherein said control comprises an electronic band-pass filter;

wherein said output signal is received by said control, said control generating a control signal indicative of detection of a human within the compartment; and

wherein said first sensing element and said second sensing element being thermally isolated from the surface.

33. A system according to claim 32, wherein said filter element transmits radiation of wavelength greater than about 3 microns.

34. A system according to claim 33, wherein said filter element comprises at least one of Ge and Si.

35. A system according to claim 33, wherein said filter element comprises ZnS.

36. A system according to claim 33, wherein said filter element comprises Polyolefin.

37. A system according to claim 33, wherein said pyroelectric sensor and said filter element are provided as a module.

38. A system according to claim 32, wherein said electronic band-pass filter passes frequencies greater than 0.1 Hz.

39. A system according to claim 32, wherein said electronic band-pass filter passes frequencies greater than 0.5 Hz.

40. A system according to claim 32, wherein said electronic band-pass filter passes frequencies greater than 0.1 Hz and less than 10 Hz.

41. A system according to claim 32, wherein said electronic band-pass filter passes frequencies greater than 0.5 Hz and less than 10 Hz.

42. A system according to claim 32, wherein said electronic band-pass filter passes frequencies greater than 1 Hz and less than 5 Hz.

43. A system according to claim 32, wherein said filter element preferentially passes radiation having wavelength between approximately 8 and 14 microns.

44. A system according to claim 32, wherein said control resolves movement of a human moving at a distance of within about 1 to 5 meters of said pyroelectric sensor.

45. A system according to claim 32, wherein said control resolves movement of a human moving at a frequency of approximately 5 Hz.

46. A system according to claim 32, wherein said system has a power consumption of less than 1 Watt when connected to vehicle battery power and when the vehicle is in the parked state.

47. A system according to claim 32, wherein said system has a power consumption of less than 0.02 Watt when connected to vehicle battery power and when the vehicle is in the parked state.

48. A system according to claim 32, further comprising a lens, said lens focusing incident radiation onto said pyroelectric sensor.

49. A system according to claim 48, wherein said lens comprises a material that transmits radiation in approximately the 8 to 14 micron wavelength range.

50. A system according to claim 48, wherein said lens blocks radiation having a wavelength of approximately 0.3 to 3 microns.

51. A system according to claim 48, wherein said lens comprises a material comprising at least one of Ge, Si, ZnS, CdS and a polyolefin.

52. A system according to claim 48, wherein said lens comprises a polyolefin material.

53. A system according to claim 48, wherein said lens comprises a material including at least one of a polypropylene material, a polyethylene material and a polymethylpentene material, or a copolymer thereof.

54. A system according to claim 48, wherein said lens comprises at least one of a fish eye lens, a diffractive optic lens, a wide angle lens and a Fresnel lens.

55. A system according to claim 48, wherein said lens comprises a plastic lens.

56. A system according to claim 32, wherein said system consumes a current of less than approximately 5.0 mA when operating under vehicle battery power.

57. A system according to claim 32, wherein said system consumes a current of less than approximately 1.5 mA when operating under vehicle battery power.

58. A system according to claim 32, wherein said compartment comprises an interior compartment of the vehicle.

59. A system according to claim 32, wherein said control comprises an application specific integrated circuit.

60. A system according to claim 32, wherein said opposed first and second sensing elements are arranged in a parallel opposed connection.

61. A system according to claim 32, wherein said opposed first and second sensing elements are arranged in a series opposed connection.

62. A system according to claim 32, wherein said compartment comprises a trunk compartment of the vehicle.

63. A system for detecting the presence of a human in a compartment of a vehicle comprising:

a pyroelectric sensor disposed at a surface of the compartment and a control coupled to said pyroelectric sensor;

said pyroelectric sensor comprising a first sensing element and a second sensing element, said first sensing element arranged in an opposed electrical connection with respect to said second sensing element whereby infrared radiation from a human moving within the compartment is differentially detected by said first sensing element and said second sensing element, and ambient thermal radiation is commonly detected by said first sensing element and said second sensing element, thereby producing an output signal with reduced sensitivity to ambient thermal radiation;

wherein a radiation filter element is disposed in front of said pyroelectric sensor;

wherein said system further comprises a lens, said lens focusing incident radiation onto said pyroelectric sensor;

wherein said output signal is received by said control, said control generating a control signal indicative of detection of a human within the compartment; and

wherein said first sensing element and said second sensing element being thermally isolated from the surface.

64. A system according to claim 63, wherein said filter element transmits radiation of wavelength greater than about 3 microns.

65. A system according to claim 64, wherein said filter element comprises at least one of Ge and Si.

66. A system according to claim 64, wherein said filter element comprises ZnS.

67. A system according to claim 64, wherein said filter element comprises Polyolefin.

68. A system according to claim 64, wherein said pyroelectric sensor and said filter element are provided as a module.

69. A system according to claim 63, wherein said control comprises an electronic band-pass filter.

70. A system according to claim 69, wherein said electronic band-pass filter passes frequencies greater than 0.1 Hz.

71. A system according to claim 69, wherein said electronic band-pass filter passes frequencies greater than 0.1 Hz and less than 10 Hz.

72. A system according to claim 69, wherein said electronic band-pass filter passes frequencies greater than 0.5 Hz and less than 10 Hz.

73. A system according to claim 69, wherein said electronic band-pass filter passes frequencies greater than 1 Hz and less 5 Hz.

74. A system according to claim 63, wherein said filter element preferentially passes radiation having wavelength between approximately 8 and 14 microns.

75. A system according to claim 63, wherein said control resolves movement of a human moving at a distance of within about 1 to 5 meters of said pyroelectric sensor.

76. A system according to claim 63, wherein said control resolves movement of a human moving at a frequency of approximately 5 Hz.

77. A system according to claim 63, wherein said system has a power consumption of less than 1 Watt when connected to vehicle battery power and when the vehicle is in the parked state.

78. A system according to claim 63, wherein said system has a power consumption of less than 0.02 Watt when connected to vehicle battery power and when the vehicle is in the parked state.

79. A system according to claim 63, wherein said lens comprises a material that transmits radiation of at least 8 microns in wavelength.

80. A system according to claim 79, wherein said lens blocks radiation having a wavelength of approximately 0.3 to 3 microns.

81. A system according to claim 79, wherein said lens comprises a material comprising at least one of Ge, Si, ZnS, CdS and a polyolefin.

82. A system according to claim 79, wherein said lens comprises a polyolefin material.

83. A system according to claim 79, wherein said lens comprises a material including at least one of a polypropylene material, a polyethylene material and a polymethylpentene material, or a copolymer thereof.

84. A system according to claim 79, wherein said lens comprises at least one of a fish eye lens, a diffractive optic lens, a wide angle lens and a Fresnel lens.

85. A system according to claim 79, wherein said lens comprises a plastic lens.

86. A system according to claim 63, wherein said lens comprises a material that transmits radiation in approximately the 8 to 14 micron wavelength range.

87. A system according to claim 63, wherein said system consumes a current of less than approximately 5.0 mA when operating under vehicle battery power.

88. A system according to claim 63, wherein said system consumes a current of less than approximately 1.5 mA when operating under vehicle battery power.

89. A system according to claim 63, wherein said compartment comprises an interior compartment of the vehicle.

90. A system according to claim 63, wherein said control comprises an application specific integrated circuit.

91. A system according to claim 63, wherein said opposed first and second sensing elements are arranged in a parallel opposed connection.

92. A system according to claim 63, wherein said opposed first and second sensing elements are arranged in a series opposed connection.

93. A system according to claim 63, wherein said compartment comprises a trunk compartment of the vehicle.