Precipitation sensor

• US 6,768,422 B2
• Filed: 01/29/2002
• Issued: 07/27/2004
• Est. Priority Date: 10/30/1997
• Status: Expired due to Fees

• Current Assignee: Donnelly Corporation (Magna International Incorporated)
• Original Assignee: Donnelly Corporation (Magna International Incorporated)
• Inventors: Larson, Mark L, Bos, Brent J, Lynam, Niall R, Schofield, Kenneth
• Primary Examiner(s): TRIEU, VAN THANH
• Application Number:
  US10/059,769
• Publication Number:
  US 20020121972A1
• Time in Patent Office: 910 Days
• Field of Search: 340/601, 340/602, 340/933, 250/208.1, 250/227.25, 250/341.7, 250/339.1, 250/573, 318/444, 318/483, 318/DIG.2, 152/500.01, 152/501.2, 15D/IG.15
• US Class Current: 340/602
• CPC Class Codes: B60H 1/00785 by the detection of humidity or frost
• CPC Class Codes: B60N 2/002 Seats provided with an occupancy detection means mounted therein or thereon detection means responsive to presence or absence of children B60N2/266
• CPC Class Codes: B60R 2001/1223 with sensors or transducers
• CPC Class Codes: B60S 1/0822 characterized by the arrangement or type of detection means
• CPC Class Codes: B60S 1/0833 Optical rain sensor
• CPC Class Codes: B60S 1/0837 with a particular arrangement of the optical elements
• CPC Class Codes: B60S 1/0844 including a camera
• CPC Class Codes: B60S 1/0885 the sensor being integrated in a rear-view mirror module
• CPC Class Codes: B60S 1/0888 characterized by the attachment of the elements in a unit
• CPC Class Codes: G06V 20/56 exterior to a vehicle by using sensors mounted on the vehicle
• CPC Class Codes: Y10S 318/02 Windshield wiper controls

Abstract

A vehicular precipitation sensor which detects precipitation on a vehicle window includes an imaging array sensor directed at the vehicle window from inside the vehicle, and a control operable to detect precipitation at a surface of the vehicle window in response to an output of the imaging array sensor. The imaging array sensor includes a plurality of pixels which sense a light value of incident radiation. The control controls an accessory of the vehicle in response to the precipitation detected reaching a threshold level of precipitation. The threshold level of detected precipitation is preferably adjustable in response to a level of ambient light present at the window. The rain sensor may include an illumination device which is preferably operable in a pulse mode, whereby the control is operable to reduce noise of the output of the imaging array sensor as a function of the pulse mode.

Claims

1. A vehicular precipitation sensor which senses precipitation consisting of at least one of rain and fog on a vehicle window, said vehicular precipitation sensor comprising:

an imaging array sensor directed at the vehicle window from inside the vehicle, said imaging array sensor comprising a plurality of pixels, said pixels sensing a light value of incident radiation, said imaging array sensor comprising one of a CMOS and a CCD sensor. said imaging array sensor being responsive at least to incident visible light, said imaging array sensor capturing images of precipitation on the window, said imaging array sensor generating an output indicative of said captured images; and

a control operable to process said output to detect precipitation at a surface of the vehicle window in response to said output of said imaging array sensor, said control controlling an accessory of the vehicle in response to the precipitation detected reaching a threshold level of detected precipitation, said threshold level of detected precipitation being adjustable in response to at least a level of ambient visible light present at the window.

2. The vehicular precipitation sensor of claim 1, wherein said imaging array sensor is operable to detect precipitation which includes water droplets at an exterior surface of the vehicle window.

3. The vehicular precipitation sensor of claim 1, wherein said imaging array sensor is operable to detect precipitation which includes fog particles at an interior surface of the vehicle window.

4. The vehicular precipitation sensor of claim 1, wherein said imaging array sensor is operable to detect precipitation which includes water droplets at an exterior surface of the vehicle window and fog particles at an interior surface of the vehicle window.

5. The vehicular precipitation sensor of claim 1, wherein said accessory comprises a window wiper of the vehicle.

6. The vehicular precipitation sensor of claim 5, wherein said control is operable to control said window wiper of the vehicle in response to said imaging array sensor detecting precipitation at an exterior surface of the window.

7. The vehicular precipitation sensor of claim 6, wherein said control is operable to control a windshield wiper of the vehicle and a rear window wiper of the vehicle in response to said imaging array sensor detecting precipitation at the exterior surface of the window.

8. The vehicular precipitation sensor of claim 7, wherein said control causes the rear window wiper to cycle for every N cycles of the windshield wiper, wherein N is greater than one.

9. The vehicular precipitation sensor of claim 1, wherein said accessory comprises a movable window of the vehicle.

10. The vehicular precipitation sensor of claim 9, wherein said control is operable to control a movable window of the vehicle to close the movable window in response to said imaging array sensor detecting precipitation at an exterior surface of the window.

11. The vehicular precipitation sensor of claim 1, wherein said accessory comprises a defogging system of the vehicle.

12. The vehicular precipitation sensor of claim 11, wherein said control is operable to control a defogging system of the vehicle in response to said imaging array sensor detecting precipitation at an interior surface of the window.

13. The vehicular precipitation sensor of claim 1, including a polarizing filter positionable between the vehicle window and said imaging array sensor.

14. The vehicular precipitation sensor of claim 1, including an illumination device for illuminating the vehicle window in an area near said imaging array sensor.

15. The vehicular precipitation sensor of claim 14, wherein said illumination device provides illumination having an illumination wavelength approximately that of an infrared wavelength.

16. The vehicular precipitation sensor of claim 14, including an illumination device control for at least occasionally activating said illumination device.

17. The vehicular precipitation sensor of claim 16, wherein said illumination device is pulsed on and off by said illumination device control.

18. The vehicular precipitation sensor of claim 17, wherein during low light conditions, said imaging array sensor is exposed to the vehicle window when said illumination device is pulsed on and not exposed to the vehicle window when said illumination device is pulsed off.

19. The vehicular precipitation sensor of claim 17, wherein said illumination device is pulsed on and off at least two times.

20. The vehicular precipitation sensor of claim 19, wherein said output of said imaging array sensor includes noise, said control being operable to reduce said noise of said output of said image array sensor as a function of the pulsation of said illumination device.

21. The vehicular precipitation sensor of claim 16, wherein said illumination device control activates said illumination device during low light conditions.

22. The vehicular precipitation sensor of claim 16, wherein said illumination device control senses ambient light at the window.

23. The vehicular precipitation sensor of claim 22, wherein said illumination device control activates said illumination device in low ambient light conditions.

24. The vehicular precipitation sensor of claim 22, wherein said threshold level of detected precipitation is adjustable in response to said illumination device control.

25. The vehicular precipitation sensor of claim 1, wherein said threshold level of detected precipitation is decreased in response to a low level of ambient light at the vehicle window.

26. The vehicular precipitation sensor of claim 1, wherein said threshold level of detected precipitation is increased in response to a high level of ambient light at the vehicle window.

27. The vehicular precipitation sensor of claim 1, wherein said threshold level of detected precipitation comprises a first threshold value during night-time conditions and a second threshold value during day time conditions, said second threshold value being greater than said first threshold value.

28. The vehicular precipitation sensor of claim 1, wherein said imaging array sensor comprises a CMOS sensor.

29. A vehicular precipitation sensor which senses at least one of rain and fog on a vehicle window, said vehicular precipitation sensor comprising:

an imaging array sensor directed at the vehicle window from inside the vehicle, said imaging array sensor comprising a plurality of pixels, said pixels sensing a light value of incident radiation, said imaging array sensor being responsive at least to incident visible light, said imaging array sensor capturing images of precipitation on the window, said imaging array sensor generating an output indicative of said captured images;

an illumination device for providing illumination at least occasionally at the vehicle window, said illumination device being operable in a pulse mode to pulse said illumination device on and off at least two times; and

a control operable to process said output to detect precipitation at a surface of the vehicle window in response to said output of said imaging array sensor, said output of said imaging array sensor including a signal indicative of precipitation at said surface of the vehicle window and said output of said imaging array sensor further including noise, said control being operable to reduce said noise of said output of said imaging array sensor as a function of said pulse mode of said illumination device, said control controlling an accessory of the vehicle in response to the precipitation detected.

30. The vehicular precipitation sensor of claim 29, wherein said imaging array sensor is operable to detect precipitation which includes water droplets at an exterior surface of the vehicle window.

31. The vehicular precipitation sensor of claim 29, wherein said imaging array sensor is operable to detect precipitation which includes fog particles at an interior surface of the vehicle window.

32. The vehicular precipitation sensor of claim 29, wherein said imaging array sensor is operable to detect precipitation which includes water droplets at an exterior surface of the vehicle window and fog particles at an interior surface of the vehicle window.

33. The vehicular precipitation sensor of claim 29, wherein said accessory comprises a window wiper of the vehicle.

34. The vehicular precipitation sensor of claim 33, wherein said control is operable to control said window wiper of the vehicle in response to said imaging array sensor detecting precipitation at an exterior surface of the window.

35. The vehicular precipitation sensor of claim 34, wherein said control is operable to control a windshield wiper of the vehicle and a rear window wiper of the vehicle in response to said imaging array sensor detecting precipitation at the exterior surface of the window.

36. The vehicular precipitation sensor of claim 35, wherein said control causes the rear window wiper to cycle for every N cycles of the windshield wiper, wherein N is greater than one.

37. The vehicular precipitation sensor of claim 29, wherein said accessory comprises a movable window of the vehicle.

38. The vehicular precipitation sensor of claim 37, wherein said control is operable to control a movable window of the vehicle to close the movable window in response to said imaging array sensor detecting precipitation at an exterior surface of the window.

39. The vehicular precipitation sensor of claim 29, wherein said accessory comprises a defogging system of the vehicle.

40. The vehicular precipitation sensor of claim 39, wherein said control is operable to control a defogging system of the vehicle in response to said imaging array sensor detecting precipitation at an interior surface of the window.

41. The vehicular precipitation sensor of claim 29, including a polarizing filter positionable between the vehicle window and said imaging array sensor.

42. The vehicular precipitation sensor of claim 29, wherein said illumination device provides illumination having an illumination wavelength approximately that of an infrared wavelength.

43. The vehicular precipitation sensor of claim 29, including an illumination device control for at least occasionally activating said illumination device.

44. The vehicular precipitation sensor of claim 43, wherein said illumination device is pulsed on and off by said illumination device control.

45. The vehicular precipitation sensor of claim 44, wherein during low light conditions, said imaging array sensor is exposed to the vehicle window when said illumination device is pulsed on and not exposed to the vehicle window when said illumination device is pulsed off.

46. The vehicular precipitation sensor of claim 43, wherein said illumination device control activates said illumination device during low light conditions.

47. The vehicular precipitation sensor of claim 43, wherein said illumination device control senses ambient light at the window.

48. The vehicular precipitation sensor of claim 47, wherein said illumination device control activates said illumination device in low ambient light conditions.

49. The vehicular precipitation sensor of claim 47, wherein said control is operable to control said accessory in response to a threshold level of detected precipitation at the vehicle window.

50. The vehicular precipitation sensor of claim 49, wherein said threshold level of detected precipitation is adjustable in response to said illumination device control.

51. The vehicular precipitation sensor of claim 50, wherein said threshold level of detected precipitation is decreased in response to a low level of ambient light at the vehicle window.

52. The vehicular precipitation sensor of claim 50, wherein said threshold level of detected precipitation is increased in response to a high level of ambient light at the vehicle window.

53. The vehicular precipitation sensor of claim 29, wherein said imaging array sensor comprises a CMOS sensor.

54. A vehicular precipitation sensor which senses precipitation consisting of at least one of rain and fog on a vehicle window, said vehicular precipitation sensor comprising:

an imaging array sensor directed at the vehicle window from inside the vehicle, said imaging array sensor comprising a plurality of pixels, said pixels sensing a light value of incident radiation, said imaging array sensor capturing images of precipitation on the window, said imaging array sensor generating an output indicative of said captured images; and

a control operable to process said output to detect precipitation at a surface of the vehicle window in response to said output of said imaging array sensor, said control controlling an accessory of the vehicle in response to the precipitation detected reaching a threshold level of detected precipitation, said control being operable to control at least one other accessory of the vehicle in response to said output of said imaging array sensor, said at least one other accessory comprising at least one of a headlamp, a cruise control, and a lane departure warning.

55. The vehicular precipitation sensor of claim 54, wherein said imaging array sensor comprises one of a CMOS and a CCD sensor.

56. The vehicular precipitation sensor of claim 54, wherein said imaging array sensor is responsive at least to incident visible light

57. The vehicular precipitation sensor of claim 54, wherein said imaging array sensor is operable to detect precipitation which includes water droplets at an exterior surface of the vehicle window.

58. The vehicular precipitation sensor of claim 54, wherein said imaging array sensor is operable to detect precipitation which includes fog particles at an interior surface of the vehicle window.

59. The vehicular precipitation sensor of claim 54, wherein said imaging array sensor is operable to detect precipitation which includes water droplets at an exterior surface of the vehicle window and fog particles at an interior surface of the vehicle window.

60. The vehicular precipitation sensor of claim 54, wherein said accessory comprises a window wiper of the vehicle.

61. The vehicular precipitation sensor of claim 60, wherein said control is operable to control said window wiper of the vehicle in response to said control detecting precipitation at an exterior surface of the window.

62. The vehicular precipitation sensor of claim 61, wherein said control is operable to control a windshield wiper of the vehicle and a rear window wiper of the vehicle in response to said imaging array sensor detecting precipitation at the exterior surface of the window.

63. The vehicular precipitation sensor of claim 62, wherein said control causes the rear window wiper to cycle for every N cycles of the windshield wiper, wherein N is greater than one.

64. The vehicular precipitation sensor of claim 54, wherein said accessory comprises a movable window of the vehicle.

65. The vehicular precipitation sensor of claim 64, wherein said control is operable to control a movable window of the vehicle to close the movable window in response to said control detecting precipitation at an exterior surface of the window.

66. The vehicular precipitation sensor of claim 54, wherein said accessory comprises a defogging system of the vehicle.

67. The vehicular precipitation sensor of claim 66, wherein said control is operable to control a defogging system of the vehicle in response to said control detecting precipitation at an interior surface of the window.

68. The vehicular precipitation sensor of claim 54, wherein said threshold level of detected precipitation is adjustable in response to at least a level of ambient visible light present at the window.

69. The vehicular precipitation sensor of claim 68, wherein said threshold level of detected precipitation is decreased in response to a low level of ambient light at the vehicle window.

70. The vehicular precipitation sensor of claim 68, wherein said threshold level of detected precipitation is increased in response to a high level of ambient light at the vehicle window.

71. The vehicular precipitation sensor of claim 54, wherein said threshold level of detected precipitation comprises a first threshold value during night-time conditions and a second threshold value during day time conditions, said second threshold value being greater than said first threshold value.

72. The vehicular precipitation sensor of claim 54, wherein said at least one other accessory comprises a headlamp.

73. The vehicular precipitation sensor of claim 54, wherein said at least one other accessory comprises a cruise control.

74. The vehicular precipitation sensor of claim 54, wherein said at least one other accessory comprises a lane departure warning.

75. The vehicular precipitation sensor of claim 54, wherein said at least one other accessory comprises a headlamp and a lane departure warning.