Moisture sensor and windshield fog detector

• US 20040144911A1
• Filed: 01/19/2004
• Published: 07/29/2004
• Est. Priority Date: 09/16/1997
• Status: Active Grant

• Current Assignee: Charles David Iv Kibler, Harold C. Ockerse, Joseph S. Stam
• Original Assignee: Charles David Iv Kibler, Harold C. Ockerse, Joseph S. Stam
• Inventors: Stam, Joseph S., Ockerse, Harold C., Kibler, Charles David IV
• Granted Patent: US 7,019,275 B2
• Time in Patent Office: Days
• US Class Current: 250/208.1
• CPC Class Codes: B60Q 1/143 combined with another condition, e.g. using vehicle recognition from camera images or activation of wipers
• CPC Class Codes: B60Q 2300/312 Adverse weather
• CPC Class Codes: B60Q 2300/314 Ambient light
• CPC Class Codes: B60S 1/0822 characterized by the arrangement or type of detection means
• 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: G06V 20/56 exterior to a vehicle by using sensors mounted on the vehicle
• CPC Class Codes: Y10S 15/15 Moisture responsive

Abstract

The system of the present invention is configured to detect moisture on a surface and includes a sensor that may be divided into a plurality of subwindows. At least one of the subwindows has a sensitivity that is independently variable. The system may further include an optical system operative to direct light rays from at least a portion of the surface onto the sensor, and a processing system in communication with the sensor and operative to independently adjust the sensitivity of the at least one subwindow and to analyze data from the sensor to detect moisture. The processing system may control the windshield wipers based upon a number of subwindows in which moisture is detected.

Claims

1. A system for detecting moisture on a surface comprising:

a sensor that is divided into a plurality of subwindows each having a sensitivity that is variable independent of the other subwindows;

an optical system operative to direct light rays from at least a portion of the surface onto said sensor; and

a processing system in communication with said sensor and operative to adjust the sensitivity of the subwindows and to analyze data from said sensor to detect moisture on the surface.

2. The system of claim 1, wherein said processing system adjusts the sensitivity of the subwindows by adjusting an integration period during which said sensor accumulates charge in response to light incident of said sensor.

3. The system of claim 1, wherein said processing system adjusts the sensitivity of a subwindow by determining an average grayscale value for pixels forming the subwindow, comparing the average grayscale value with a target average value, and adjusting the exposure time of the subwindow as a result of the comparison.

4. The system of claim 1, wherein said processing system controls the windshield wipers based upon a number of subwindows in which moisture is detected.

5. The system of claim 1 and further comprising:

a supplemental illuminator for selectively illuminating the portion of the surface imaged onto the sensor; and

memory for storing a first set of data obtained by said sensor when the supplemental illuminator is illuminating the portion of the surface, and for storing a second set of data obtained by said sensor when the supplemental illuminator is not illuminating the portion of the surface,

wherein said processing system is in communication with said memory, said supplemental illuminator, and said sensor and operative to compare the first and second sets of data stored in said memory and to analyze results of the comparison to detect moisture on the surface.

6. A windshield wiper control system for a vehicle comprising:

a sensor that is divided into a plurality of subwindows;

an optical system operative to direct light rays from at least a portion of the surface of the windshield onto said sensor; and

a processing system in communication with said sensor and operative to analyze data from said sensor to determine whether moisture is detected in each subwindow and to control the windshield wipers based upon a number of subwindows in which moisture is detected.

7. The windshield wiper control system of claim 6, wherein said processing system is configured to detect edges of objects in each subwindow.

8. The windshield wiper control system of claim 7, wherein said processing system determines that moisture is present when the number of subwindows in which an edge is detected reaches a predetermined threshold.

9. The windshield wiper control system of claim 6, wherein said processing system determines a variance between the grayscale values of the pixels in a subwindow and excludes the subwindow from consideration if the subwindow has a variance exceeding a threshold level.

10. The windshield wiper control system of claim 6, wherein said processing system is responsive to at least one remote device to enable or disable automatic control of the windshield wipers.

11. The windshield wiper control system of claim 6, wherein at least one of said subwindows has a sensitivity that is independently variable, and said processing system is operative to independently adjust the sensitivity of said at least one subwindow and to analyze data from said sensor to detect moisture.

12. The windshield wiper control system of claim 6, wherein said processing system determines a number of subwindows in which moisture is detected and controls the windshield wipers if the number of subwindows in which moisture is detected exceeds a threshold number.

13. A windshield wiper control system for a vehicle comprising:

a sensor;

an optical system operative to direct light rays from at least a portion of the surface of the windshield onto said sensor; and

a processing system in communication with said sensor and operative to analyze data from said sensor to detect moisture on the windshield and to automatically activate the windshield wipers when moisture is detected, wherein said processing system is responsive to at least one remote device to enable or disable automatic control of the windshield wipers.

14. The windshield wiper control system of claim 13, wherein the at least one remote device is associated with a car wash such that automatic control of the windshield wipers may be disabled prior to entry into the car wash.

15. The windshield wiper control system of claim 14, wherein said processing system is coupled to an RF receiver and the at least one remote device is an RF transmitter, such that said processing system enables or disables automatic activation of the windshield wipers when a predetermined signal is received by the RF receiver from the RF transmitter.

16. The windshield wiper control system of claim 15, wherein the RF receiver is a remote keyless entry receiver.

17. The windshield wiper control system of claim 14, wherein said processing system is coupled to a microwave receiver that receives signals from the at least one remote device, which includes a plurality of satellites, wherein said processing system disables automatic activation of the windshield wipers in response to information from the microwave receiver.

18. The windshield wiper control system of claim 17, wherein the information from the microwave receiver is that microwave receiver is receiving signals from less than two satellites.

19. The windshield wiper control system of claim 18, wherein satellites are part of a global positioning system constellation and the microwave receiver is a GPS receiver.

20. The windshield wiper control system of claim 14, wherein said processing system disables manual activation of wipers.