Method and device for determining light conditions in front of a moving object, in particular a motor vehicle

• US 6,677,986 B1
• Filed: 06/14/2000
• Issued: 01/13/2004
• Est. Priority Date: 10/02/1997
• Status: Expired due to Term

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Pöchmüller, Werner
• Primary Examiner(s): DIEP, NHON THANH
• Application Number:
  US09/509,850
• Time in Patent Office: 1,308 Days
• Field of Search: 348/148, 348/149, 348/221.1, 348/223.1, 348/227.1, 348/116, 348/118, 315/82, 315/83, 315/155
• US Class Current: 348/149
• 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 2300/112 Vehicle speed
• CPC Class Codes: B60Q 2300/312 Adverse weather
• CPC Class Codes: B60Q 2300/314 Ambient light
• CPC Class Codes: B60Q 2300/322 Road curvature
• CPC Class Codes: B60Q 2300/337 Tunnels or bridges

Abstract

Method for determining the lighting conditions in front of a moving object, in particular in front of a motor vehicle. The arrangement includes a sensor unit which scans the area in front of the vehicle in the direction of vehicle travel as well as an evaluation unit which measures both the general lighting conditions and the lighting conditions in front of the vehicle in the direction of vehicle travel based on the values supplied by the sensor unit. The brightness measurement is carried out with a two-dimensional image sensor, and one or more information values relating to the lighting conditions, for example before entering a tunnel, is generated with the help of a sectoral and/or global evaluation of the brightness values measured by the image sensor in the respective sectors used on a traffic lane between the edges of the traffic lane.

Claims

1. A method for determining a lighting condition in front of a moving object corresponding to a motor vehicle, comprising the steps of:

causing a sensor unit to scan an area in front of the motor vehicle in a direction of vehicle travel;

causing an evaluation unit to measure a general lighting condition and the lighting condition in front of the motor vehicle in the direction of vehicle travel based on a plurality of values supplied by the sensor unit;

carrying out a brightness measurement with a two-dimensional image sensor; and

generating at least one information value relating to the lighting condition in front of the motor vehicle in accordance with at least one of a sectoral evaluation and a global evaluation of a brightness value measured by the two-dimensional image sensor in respective sectors, wherein the two-dimensional image sensor corresponds to one of a logarithmic image sensor and an image sensor with a non-linear conversion characteristic.

2. The method according to claim 1, wherein:

the two-dimensional image sensor corresponds to a CMOS image sensor.

3. The method according to claim 1, further comprising the step of:

measuring a brightness by averaging a pixel brightness in measurement windows.

4. The method according to claim 1, further comprising the step of:

combining the brightness measurement with an automatic traffic lane tracking system to selectively measure ambient brightness in a path of a traffic lane.

5. The method according to claim 1, further comprising the step of:

combining the brightness measurement with an object detection arrangement to detect a specific object located in a traffic lane path and to take the specific object into account during the brightness measurement.

6. The method according to claim 5, wherein:

the specific object corresponds to a truck.

7. The method according to claim 1, further comprising a performance of one of the steps of:

providing a driver of the motor vehicle with an advance warning to alert the driver to turn on a vehicle light; and

automatically activating the vehicle light in advance by turning the vehicle light on.

8. The method according to claim 1, further comprising a performance of one of the steps of:

alerting a driver of the motor vehicle to turn a vehicle light on and off based on an ambient brightness measured by the two-dimensional image sensor; and

automatically activating the vehicle light based on the ambient brightness.

9. An arrangement for determining a lighting condition in front of a moving object corresponding to a motor vehicle, comprising:

a two-dimensional image sensor onto which an area in front of the motor vehicle is mapped and that generates at least one information value relating to the lighting condition in front of the motor vehicle; and

an evaluation unit for performing at least one of a sectoral evaluation and a global evaluation of a brightness value, wherein the two-dimensional image sensor corresponds to one of a logarithmic image sensor and an image sensor with a non-linear conversion characteristic;

wherein the two-dimensional image sensor supplies the at least one information value to the evaluation unit.

10. The arrangement according to claim 9, wherein:

the two-dimensional image sensor corresponds to a CMOS image sensor.

11. The arrangement according to claim 9, further comprising one of:

an arrangement for providing a driver of the motor vehicle with an advance warning to alert the driver to turn on a vehicle light; and

an arrangement for automatically activating the vehicle light in advance by turning the vehicle light on.

12. The arrangement according to claim 9, further comprising one of:

an arrangement for alerting a driver of the motor vehicle to turn a vehicle light on and off based on an ambient brightness measured by the two-dimensional image sensor; and

an arrangement for automatically activating the vehicle light based on the ambient brightness.