Windscreen sensing and wiper control system

• US 6,020,704 A
• Filed: 12/02/1997
• Issued: 02/01/2000
• Est. Priority Date: 12/02/1997
• Status: Expired due to Term

• Current Assignee: Valeo Electrical Systems Incorporated (Valeo SE)
• Original Assignee: Valeo Electrical Systems Incorporated (Valeo SE)
• Inventors: Buschur, Jeffrey J.
• Primary Examiner(s): Masih, Karen
• Application Number:
  US08/982,560
• Time in Patent Office: 791 Days
• Field of Search: 318/483, 318/444, 318/480, 318/443, 318/DIG. 2, 15/250 C, 15/250.12, 15/250.13, 15/250.17, 307/9.1, 307/10.1
• US Class Current: 318/483
• 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 1/0844 including a camera
• CPC Class Codes: G06V 20/56 exterior to a vehicle by using sensors mounted on the vehicle

Abstract

An apparatus for detecting moisture on the windscreen of a motor vehicle has an illumination source and a light sensor mounted within the motor vehicle. The light sensor detects light rays from the light source reflected off the windscreen via a diffusion surface within the motor vehicle. Based upon the sensed reflected light, an image processor in communication with the light sensor creates an image of a portion of the windscreen that the processor analyzes to determine the moisture condition of the windscreen.

A method for controlling the operation of the windscreen wiper system monitors light reflected from a portion of a windscreen and creates an image of the moisture condition of the windscreen based on the reflected light. The image is analyzed to determine the configuration of light intensities in predetermined zones. From the light intensity configuration, the moisture condition of the windscreen is determined. The sensed moisture condition parameters are compared to a threshold array and a signal based upon this comparison is communicated the wiper, defogger, or headlight control system.

Claims

1. An apparatus for a motor vehicle in which a windshield at least partially encloses an interior compartment for housing passengers, said apparatus for detecting moisture on said windscreen, comprising:

illumination source mounted within said motor vehicle;

diffusion surface spaced within said motor vehicle apart from said illumination source, said diffusion surface for reflecting light rays from said illumination source onto said windscreen;

light sensor spaced within said interior compartment apart from said windscreen and said diffusion surface, said light sensor for deflecting light rays reflected from said windscreen; and

image processor in communication with said light sensor, said image processor for creating an image representing said moisture on said windscreen based upon input from said light sensor.

2. The apparatus of claim 1, wherein said image processor determines the moisture condition of said windscreen from the intensity of light in predetermined zones of said image.

3. The apparatus of claim 1, wherein said illumination source is a light emitting diode.

4. The apparatus of claim 3, wherein said diode emits light of infra-red frequency.

5. The apparatus of claim 3, wherein said diode pulses in synchronization with the imaging frequency of said light sensor.

6. The apparatus of claim 2, wherein said image processor is in communication with and updates the control system of the windscreen wipers of said vehicle with information regarding said moisture condition.

7. The apparatus of claim 6, herein the operating speed of said windscreen wipers is adjusted based on said information regarding said moisture condition.

8. The apparatus of claim 2, wherein said image processor is in communication with and updates the control system of the defogger system of said vehicle with information regarding said moisture condition.

9. The apparatus of claim 8, wherein the operation of said defogger system is controlled based on said information regarding said moisture condition.

10. The apparatus of claim 6, wherein said image processor is in communication with and updates the control system of the headlights of said vehicle regarding the operating speed of the windscreen wiper system of said vehicle.

11. The apparatus of claim 10, wherein the brightness of the headlights of said vehicle is adjusted based on said operating speed.

12. The apparatus of claim 2, further comprising a test pattern placed upon said diffusion surface.

13. The apparatus of claim 12, wherein said image processor determines said moisture condition from the degree of blurring of said image of said test pattern.

14. A method for analyzing an image of a windscreen of a motor vehicle, comprising the steps of:

correcting vertical compression of said image;

comparing the brightness of a region of said image to a predetermined threshold of brightness;

determining moisture condition of said region based upon the results of said comparing step; and

updating said predetermine threshold of brightness.

15. A method for controlling the operation of the windscreen wiper system of a motor vehicle, comprising the steps of:

monitoring light reflected from a portion of a windscreen of said motor vehicle;

creating an image of the moisture condition on said portion of said windscreen based on said reflected light;

analyzing said image to determine the configuration of light intensities in predetermined zones of said image; and

determining from said configuration the moisture condition of said windscreen.

16. The method of claim 15, further comprising the step of:

storing a predetermined moisture condition profile in a processor; and

comparing said determined moisture condition to said predetermined moisture condition profile to create a moisture condition comparison.

17. The method of claim 15, further comprising the step of:

recording droplet size and percent moisture coverage when a driver actuates the wipers of said windscreen wiper system;

creating a driver parameter preference profile in a processor; and

comparing said determined moisture condition to said driver preference profile to create a moisture condition comparison.

18. The method of claim 15, further comprising the steps of:

transmitting a moisture signal based on said moisture condition comparison to the control system of the windscreen wipers of said vehicle; and

controlling said windscreen wipers based on said moisture command signal.

19. The method of claim 16, further comprising the steps of:

transmitting a wiper speed signal representing said operating speed of said windscreen wipers to the control system of the headlights of said vehicle; and

controlling said headlights based upon said wiper signal.

20. The method of claim 15, further comprising the steps of:

transmitting a moisture signal based on said moisture condition comparison to the control system of said vehicle; and

controlling the defogger system based on said defogger command signal.

21. The method of claim 15, further comprising the steps of:

transmitting a moisture signal representing said moisture condition to the control system of the headlights of said vehicle; and

adjusting the headlights based on said moisture signal.

22. A method for controlling the operation of the windscreen wiper system of a motor vehicle, comprising the steps of:

providing a diffusion surface spaced within the passenger compartment of said vehicle apart from an illumination source and from the windscreen of said motor vehicle such that at least a portion of light from said illumination source is reflected from said diffusion surface onto said windscreen;

placing a test pattern upon said diffusion surface;

monitoring light reflected from said portion of the windscreen;

creating an image of said test pattern based on said monitored light;

analyzing said the degree of blurriness of said test pattern in said image; and

determining from degree of blurriness the moisture condition of said windscreen.

23. An apparatus for detecting moisture droplets on the windscreen of a motor vehicle, comprising:

a light source mounted within said motor vehicle;

diffusion surface spaced within said motor vehicle apart from said light source for reflecting light rays from said light source onto said windscreen;

light sensor spaced within said motor vehicle apart from said windscreen and said diffusion surface for detecting light rays reflected from said windscreen; and

image processor in communication with said light source and said light sensor for creating an image representing said moisture droplets and creating information regarding the moisture condition of said windscreen based upon said image, and in communication with the windscreen wiper control system of said vehicle for adjusting the operating speed of said windscreen wipers based on said information regarding said moisture condition.

24. The apparatus of claim 23, wherein said image processor determines said moisture condition of said windscreen based upon the intensity of light in predetermined zones of said image.

25. The apparatus of claim 24, further comprising:

a test pattern placed upon said diffusion surface wherein said image processor determines said moisture condition from the degree of blurring of said image of said test pattern.

26. The apparatus of claim 23, wherein said image processor is in communication with the defogger control system of said vehicle for controlling the operation of said defogger system based on said information regarding said moisture condition, and in communication with headlight control system of said vehicle for adjusting the brightness of the headlights of said vehicle is adjusted based on said operating speed.

27. An apparatus for detecting moisture on the windscreen of a motor vehicle, comprising:

illumination source mounted within said motor vehicle for transmitting light rays onto said windscreen;

light sensor spaced within said motor vehicle apart from said windscreen and said illumination source, said light sensor for detecting light rays reflected from said windscreen; and

image processor in communication with said light sensor, said image processor for creating an image representing said moisture on said windscreen based upon input from said light sensor.