Automatic vehicle exterior light control systems

• US 8,045,760 B2
• Filed: 02/12/2004
• Issued: 10/25/2011
• Est. Priority Date: 02/21/2003
• Status: Active Grant

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Berends, Keith H., Longworth, Kevin J., Meekhof, David A., Rycenga, Brock R., Walstra, Eric J., Stam, Joseph S.
• Primary Examiner(s): Desire; Gregory M
• Assistant Examiner(s): Allison; Andrae S
• Application Number:
  US10/777,468
• Publication Number:
  US 20040201483A1
• Time in Patent Office: 2,812 Days
• Field of Search: 382/104, 382156-162, 362/465, 362/466, 340/461, 340/601, 340/600, 250/208.1
• US Class Current: 382/104
• CPC Class Codes: B60Q 1/1423 Automatic dimming circuits, i.e. switching between high beam and low beam due to change of ambient light or light level in road traffic
• CPC Class Codes: B60Q 2300/312 Adverse weather
• CPC Class Codes: B60Q 2300/332 on city roads
• CPC Class Codes: B60Q 2300/42 oncoming vehicle
• CPC Class Codes: B60Q 2300/45 Special conditions, e.g. pedestrians, road signs or potential dangers
• CPC Class Codes: G06V 20/58 Recognition of moving objects or obstacles, e.g. vehicles or pedestrians; Recognition of traffic objects, e.g. traffic signs, traffic lights or roads
• CPC Class Codes: G06V 20/588 Recognition of the road, e.g. of lane markings; Recognition of the vehicle driving pattern in relation to the road

Abstract

The present invention relates to various improvements relating to automatic vehicle equipment control systems.

Claims

1. An automatic vehicle exterior light control system comprising:

a processor configured to effect automatic operation of the light control system as a function of an ambient light value, wherein said ambient light value is a weighted average of a plurality of ambient light level readings acquired from a photo transducer;

a controller configured to generate an exterior light control signal if the light control system is operational as a function of the presence of an atmospheric condition of interest, wherein said controller is further configured to distinguish between reflections off of a highly reflective surface and reflections off of atmospheric conditions of interest based on input from at least one imager; and

wherein an exterior light control output of said controller is in a first state when reflections off of a highly reflective surface are detected and said exterior light control output is in a second state when reflections off of atmospheric conditions of interest are detected.

2. An automatic vehicle exterior light control system as in claim 1 wherein said highly reflective surface is selected from the group comprising:

an at least partially wet road, an at least partially snow covered road, an at least partially ice covered road, a surface of a snow pile along a road, and a surface of an at least partially snow covered road side.

3. An automatic vehicle exterior light control system as in claim 1 wherein said atmospheric condition of interest is selected from the group comprising:

fog, mist, snow, sleet, hail, rain, steam, smoke and dust.

4. An automatic vehicle exterior light control system as in claim 3 wherein said highly reflective surface is selected from the group comprising:

an at least partially wet road, an at least partially snow covered road, an at least partially ice covered road, a surface of a snow pile along a road, and a surface of an at least partially snow covered road side.

5. An automatic vehicle exterior light control system as in claim 1 wherein said reflections are identified by employing at least one of the parameters selected from the group comprising:

mean grayscale value of at least a portion of at least one image, total grayscale value of at least a portion of at least one image, average grayscale value of at least a portion of at least one image, slope of pixel column location versus pixel grayscale value of at least a portion of a column of pixels within at least one image, slope of pixel row location versus pixel grayscale value of at least a portion of a column of pixels within at least one image, intercept of pixel column location versus pixel grayscale value of at least a portion of a column of pixels within at least one image, slope of pixel row location versus pixel grayscale value of at least a portion of a column of pixels within at least one image, a coefficient of determination, parabolic fit of at least a portion of column pixel value averages in at least one image, multiple images of differing exposure times, inputs from vehicle pitch sensors, a low-pass filter applied to at least a portion of an image, gradual vertical cutoff in at least a portion of pixel rows within at least one image, row average grayscale value net increase moving downward in at least one image, white-to-red ratio of at least one pixel in at least one white image and at least one pixel in at least one red spectral filtered image, sum of average grayscale values for at least one row in at least one image, increase brightness of controlled vehicle'"'"'s exterior light and detect increase in reflection, at least one probability function, and at least one neural network.

6. An automatic vehicle exterior light control system as in claim 1 wherein said controller is further configured to manipulate one of the items selected from the group comprising:

an exterior light adjustment rate, an image analysis parameter, a sensitivity parameter, fog light signal, taillight brightness, a field of view parameter, a spectral filter parameter, an algorithm parameter, an algorithm activation, an algorithm deactivation, an exterior light maximum brightness limit, and an exterior light minimum brightness limit as a function of detected reflections.

7. An automatic vehicle exterior light control system as in claim 1, wherein said weighted average is of a most recent approximately 16 photo sensor readings with approximately 100 ms intervals.

8. An automatic vehicle exterior light control system as in claim 1, wherein said weighted average is an exponential time weighted average of a most recent approximately 256 photo sensor readings with 100 ms intervals.

9. An automatic vehicle exterior light control system as in claim 1, wherein said photo transducer is a high dynamic range imager, such that high dynamic range images are acquired to detect an atmospheric condition.

10. An automatic vehicle exterior light control system as in claim 9, wherein said high dynamic range image is a synthetic high dynamic range image.

11. An automatic vehicle exterior light control system as in claim 1 wherein said weighted average is calculated using an ambient short average value of the most recent ambient sensor readings taken over a period less than two seconds.

12. An automatic vehicle exterior light control system as in claim 1 wherein said ambient short average is used in determining a transition from a day lighting condition to a night lighting condition.

13. An automatic vehicle exterior light control system as in claim 1 wherein said weighted average is calculated using an ambient long average value of the ambient sensor readings taken over a period less than 30 seconds.

14. An automatic vehicle exterior light control system as in claim 1 wherein said ambient long average value is used in the transition from a night lighting condition to a day lighting condition.

15. An automatic vehicle exterior light control system, comprising:

a processor configured to effect automatic operation of the light control system as a function of an ambient light value, wherein said ambient light value is a weighted average of a plurality of ambient light level readings acquired from a photo transducer;

a controller configured to identify the source of a reflection in an image if the light control system is operational by employing at least one of the parameters selected from the group comprising;

mean grayscale value of at least a portion of at least one image, total grayscale value of at least a portion of at least one image, average grayscale value of at least a portion of at least one image, slope of pixel column location versus pixel grayscale value of at least a portion of a column of pixels within at least one image, slope of pixel row location versus pixel grayscale value of at least a portion of a column of pixels within at least one image, intercept of pixel column location versus pixel grayscale value of at least a portion of a column of pixels within at least one image, slope of pixel row location versus pixel grayscale value of at least a portion of a column of pixels within at least one image, a coefficient of determination, parabolic fit of at least a portion of column pixel value averages in at least one image, multiple images of differing exposure times, inputs from vehicle pitch sensors, a low-pass filter applied to at least a portion of an image, gradual vertical cutoff in at least a portion of pixel rows within at least one image, row average grayscale value net increase moving downward in at least one image, white-to-red ratio of at least one pixel in at least one white image and at least one pixel in at least one red spectral filtered image, sum of average grayscale values for at least one row in at least one image, increase brightness of controlled vehicle'"'"'s exterior light and detect increase in reflection, at least one probability function, and at least one neural network; and

wherein a state of an exterior light control output of said controller is at least partially dependent upon the source of said reflection in said image.

16. An automatic vehicle exterior light control system as in claim 15 wherein said controller is further configured to manipulate one of the items selected from the group comprising:

an exterior light adjustment rate, an image analysis parameter, a sensitivity parameter, fog light signal, taillight brightness, a field of view parameter, a spectral filter parameter, an algorithm parameter, an algorithm activation, an algorithm deactivation, an exterior light maximum brightness limit, and an exterior light minimum brightness limit as a function of detected reflections.

17. An automatic vehicle exterior light control system, comprising:

a processor configured to effect automatic operation the automatic vehicle exterior light control system as a function of an ambient light value if the light control system is operational, wherein said ambient light value is a weighted average of a plurality of ambient light level readings acquired from a photo transducer, said controller is further configured to detect at least one of a pedestrian and a bicyclist and further configured to provide a corresponding indication to an operator of a controlled vehicle;

wherein a state of an exterior light control output of said controller is at least partially dependent upon detection of either a pedestrian or a bicyclist based on input from at least one imager.

18. An automatic vehicle exterior light control system as in claim 17 further configured to disable automatic operation of at least one high beam headlight in response to an operator activated input device.