Continuously variable headlamp control

• US 6,429,594 B1
• Filed: 08/24/2001
• Issued: 08/06/2002
• Est. Priority Date: 09/18/1998
• Status: Expired due to Term

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Bauer, Frederick T., Stam, Joseph S., Bechtel, Jon H.
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): TRAN, THUY V
• Application Number:
  US09/938,774
• Publication Number:
  US 20020060522A1
• Time in Patent Office: 347 Days
• Field of Search: 315/82, 315/77, 250/208.1, 250/214.AL, 307/10.8, 340/437, 340/438, 340/468, 340/469, 340/936, 340/939, 362/464, 362/465
• US Class Current: 315/82
• CPC Class Codes: B60Q 1/085 due to special conditions, e.g. adverse weather, type of road, badly illuminated road signs or potential dangers B60Q1/10, B60Q1/12, B60Q1/1423 take precedence
• 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 1/18 being additional front lights bracket mounted headlights B60Q1/0483
• CPC Class Codes: B60Q 2300/054 Variable non-standard intensity, i.e. emission of various beam intensities different from standard intensities, e.g. continuous or stepped transitions of intensity
• CPC Class Codes: B60Q 2300/056 Special anti-blinding beams, e.g. a standard beam is chopped or moved in order not to blind
• CPC Class Codes: B60Q 2300/112 Vehicle speed
• CPC Class Codes: B60Q 2300/114 Vehicle acceleration or deceleration
• CPC Class Codes: B60Q 2300/132 Pitch
• CPC Class Codes: B60Q 2300/312 Adverse weather
• CPC Class Codes: B60Q 2300/314 Ambient light
• CPC Class Codes: B60Q 2300/3321 Detection of streetlights
• CPC Class Codes: B60Q 2300/41 preceding vehicle
• CPC Class Codes: B60Q 2300/42 oncoming vehicle
• CPC Class Codes: B60Q 2400/30 Daytime running lights [DRL], e.g. circuits or arrangements therefor
• CPC Class Codes: G06V 20/584 of vehicle lights or traffic lights

Abstract

A system for automatically controlling continuously variable headlamps on a controlled vehicle includes an imaging system capable of determining lateral and elevational locations of headlamps from oncoming vehicles and tail lamps from leading vehicles. The system also includes a control unit that can acquire an image from in front of the controlled vehicle. The image covers a glare area including points at which drivers of oncoming and leading vehicles would perceive the headlamps to cause excessive glare. The image is processed to determine if at least one oncoming or leading vehicle is within the glare area. If at least one vehicle is within the glare area, the headlamp illumination range is reduced. Otherwise, the illumination range is set to full illumination range.

Claims

1. An illumination control system for controlling exterior illumination lights of a controlled vehicle where the exterior lights are capable of producing different illumination patterns, wherein at least one of the exterior lights includes a filament and produces illumination by heating the filament, said control system comprising:

an array of sensors for generating electrical signals; and

a control circuit in communication with the exterior lights and operable to acquire and process electrical signals received from said array of sensors to determine if at least one vehicle is in front of the controlled vehicle and, if at least one vehicle is detected in front of the controlled vehicle, said control circuit is operable to change the illumination pattern of the exterior lights,

wherein, when the at least one exterior light including a filament is not to emit light, a low amount of current is supplied to the filament so as to heat the filament without causing the filament to emit light.

2. The illumination control system of claim 1, wherein said array of sensors is a two-dimensional array of sensors.

3. The illumination control system of claim 1, wherein said control circuit causes low amount of current to be supplied to the filament.

4. The illumination control system of claim 1, wherein said control circuit generates a pulse-width modulated control signal and supplies the pulse-width modulated control signal to at least one of said exterior lights.

5. An illumination control system for controlling exterior illumination lights of a controlled vehicle where the exterior lights are capable of producing different illumination patterns, said control system comprising:

an array of light sensors for generating electrical signals; and

a control circuit in communication with the exterior lights and operable to acquire and process electrical signals received from said array of sensors to determine if at least one vehicle is in front of the controlled vehicle and, if at least one vehicle is detected in front of the controlled vehicle, said control circuit is operable to change the illumination pattern of the exterior lights,

wherein said control circuit limits the maximum inrush current to at least one of the exterior lights.

6. The illumination control system of claim 5, wherein said control circuit generates a pulse-width modulated control signal and supplies the pulse-width modulated control signal to at least one of said exterior lights to limit the maximum inrush current thereto.

7. The illumination control system of claim 5, wherein said control circuit limits inrush current by gradually fading on the exterior lights.

8. The illumination control system of claim 5, wherein said control circuit compares a light level sensed by each sensor to a threshold value to determine whether a light source is present in front of the controlled vehicle, said control circuit adjusts the threshold value as a function of a sensed ambient light level.

9. An illumination control system for controlling exterior illumination lights of a controlled vehicle where the exterior lights are capable of producing different illumination patterns, said control system comprising:

an array of sensors, said sensors generating electrical signals representing a light level sensed by each sensor; and

a control circuit in communication with the exterior lights and operable to acquire and process electrical signals received from said array of sensors to determine if at least one vehicle is in front of the controlled vehicle and, if at least one vehicle is detected in front of the controlled vehicle, said control circuit is operable to change the illumination pattern of the exterior lights,

wherein said control circuit compares the light level sensed by each sensor to a threshold value to determine whether a light source is present in front of the controlled vehicle, said control circuit adjusts the threshold value as a function of a sensed ambient light level.

10. The illumination control system of claim 9, wherein said control circuit limits the maximum inrush current to at least one of the exterior lights.

11. The illumination control system of claim 9, wherein said control circuit is operable to increase the illumination range of at least one of the exterior lights in proportion to increasing vehicle speed except when vehicles are detected in front of the controlled vehicle.

12. The system of claim 9 and further comprising a moisture sensor operable to detect moisture, wherein said control circuit is in communication with the moisture sensor, the control circuit being operable to control operation of the at least one exterior vehicle light as a function of the detection of moisture.

13. The system of claim 12 and further comprising a first lens for focusing an image to the front of the vehicle onto said array of sensors.

14. The system of claim 12, wherein said moisture sensor includes a second array of sensors coupled to said control circuit, and a second lens for focusing light onto said second array of sensors.

15. The system of claim 12, wherein said control unit further controls windshield wipers of the controlled vehicle in response to the moisture sensor.

16. The system of claim 12, wherein said array of sensors is a two-dimensional array of sensors.

17. An illumination control system for controlling exterior illumination lights of a controlled vehicle where the exterior lights are capable of producing different illumination patterns, said control system comprising:

an array of light sensors for generating electrical signals; and

a control circuit in communication with the exterior lights and operable to acquire and process electrical signals received from said array of sensors to determine if at least one vehicle is in front of the controlled vehicle and, if at least one vehicle is detected in front of the controlled vehicle, said control circuit is operable to change the illumination pattern of the exterior lights, wherein said control circuit is operable to adjust the illumination range of at least one of the exterior lights as a function of both the speed of the controlled vehicle and the detection of a vehicle in front of the controlled vehicle.

18. The illumination control system of claim 17, wherein said control circuit is operable to increase the illumination range of at least one of the exterior lights in proportion to increasing vehicle speed except when a vehicle is detected in front of the controlled vehicle.

19. The illumination control system of claim 17, wherein said control circuit is operable to automatically calibrate the aim of the array of light sensors relative to the controlled vehicle based upon images detected by said array of light sensors.

20. The illumination control system of claim 17, wherein said control circuit limits the maximum inrush current to at least one of the exterior lights.

21. The illumination control system of claim 17, wherein said control circuit compares a light level sensed by each sensor to a threshold value to determine whether a light source is present in front of the controlled vehicle, said control circuit adjusts the threshold value as a function of a sensed ambient light level.

22. A system for controlling at least one continuously variable headlamp on a controlled vehicle, each continuously variable headlamp having an effective illumination range varied by changing vertical direction aimed, the system comprising:

an imaging system capable of determining lateral and elevational locations of headlamps from vehicles in front of the controlled vehicle; and

a control unit in communication with the imaging system and the at least one continuously variable headlamp, the control unit operable to;

(a) acquire an image in front of the at least one continuously variable headlamp, the image covering a glare area including points at which a driver of a vehicle in front of the at least one continuously variable headlamp would perceive the at least one continuously variable headlamp to cause excessive glare,

(b) process the image to determine if at least one vehicle is within the glare area,

(c) if at least one vehicle is within the glare area, determine the elevational angle between the imaging system and the lights of each of the at least one vehicle, and

(d) if at least one vehicle is within the glare area, vertically aim the at least one continuously variable headlamp such that the at least one continuously variable headlamp does not cause glare for the at least one vehicle.

23. An illumination control system for controlling exterior illumination lights of a controlled vehicle where the exterior lights are capable of producing different illumination patterns, said control system comprising:

an imaging system for obtaining an image to the front of the controlled vehicle, said imaging system including an array of sensors each generating electrical signals representing a light level sensed by the sensor; and

a control circuit in communication with the exterior lights and operable to acquire and process electrical signals received from said array of sensors to determine if at least one vehicle is in front of the controlled vehicle and, if at least one vehicle is detected in front of the controlled vehicle, said control circuit is operable to change the illumination pattern of the exterior lights,

wherein said control circuit is operable to automatically calibrate the aim of the imaging system relative to the controlled vehicle based upon images detected by said imaging system.

24. The illumination control system of claim 23, wherein said control circuit automatically calibrates the aim of the imaging system when the controlled vehicle is positioned in front of a target that can be seen by said imaging system.

25. The illumination control system of claim 23, wherein said control circuit automatically calibrates the aim of the imaging system by noting changes in the relative position of street lamps in an image detected by said imaging system.

26. An illumination control system for controlling exterior illumination lights of a controlled vehicle where the exterior lights are capable of producing different illumination patterns, said control system comprising:

an imaging system for obtaining an image to the front of the controlled vehicle, said imaging system including an array of sensors each generating electrical signals representing a light level sensed by the sensor, said array of sensors being divided into at least two subwindows; and

a control circuit in communication with the exterior lights and operable to acquire electrical signals received from said array of sensors and to process the electrical signals from said subwindows to determine if at least one vehicle is in front of the controlled vehicle and, if at least one vehicle is detected in front of the controlled vehicle, said control circuit is operable to change the illumination pattern of the exterior lights.

27. The illumination control system of claim 26, wherein said control circuit is operable to automatically calibrate the aim of said imaging system relative to the controlled vehicle based upon images detected by said imaging system.

28. The illumination control system of claim 26, wherein said control circuit limits the maximum inrush current to at least one of the exterior lights.

29. The illumination control system of claim 26, wherein said control circuit compares a light level sensed by each sensor to a threshold value to determine whether a light source is present in front of the controlled vehicle, said control circuit adjusts the threshold value as a function of a sensed ambient light level.

30. The illumination control system of claim 26, wherein said control circuit is operable to increase the illumination range of at least one of the exterior lights in proportion to increasing vehicle speed except when vehicles are detected in front of the controlled vehicle.