System for adjusting direction of optical axis of headlight

• US 20090043458A1
• Filed: 02/29/2008
• Published: 02/12/2009
• Est. Priority Date: 03/01/2007
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Hasegawa, Junichi, Kamioka, Takahiro, Horii, Yasutoshi
• Granted Patent: US 8,019,512 B2
• Time in Patent Office: Days
• US Class Current: 701/49
• 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 2300/112 Vehicle speed
• CPC Class Codes: B60Q 2300/122 Steering angle
• CPC Class Codes: B60Q 2300/132 Pitch
• CPC Class Codes: B60Q 2300/134 Yaw
• CPC Class Codes: B60Q 2300/32 Road surface or travel path
• CPC Class Codes: B60Q 2300/41 preceding vehicle
• CPC Class Codes: B60Q 2300/42 oncoming vehicle

Abstract

In a system for controlling a headlight of a vehicle to be controlled, a distance detector detects a distance between the controlled vehicle and an other vehicle ahead thereof. A determiner determines a first target direction for an optical axis of the headlight in a vertical direction when it is assumed that the optical axis of the headlight passes through a target located at the detected distance with respect to the controlled vehicle. The target has a predetermined height above a predetermined reference point. The predetermined height of the target is unchanged irrespective of change in the detected distance. A first adjuster adjusts the direction of the optical axis of the headlight in the vertical direction so that the direction of the optical axis is matched with the determined first target direction.

Claims

1. A system for controlling a headlight of a vehicle to be controlled, the system comprising:

a distance detector configured to detect a distance between the controlled vehicle and an other vehicle ahead thereof;

a determiner configured to determine a first target direction for an optical axis of the headlight in a vertical direction when it is assumed that the optical axis of the headlight passes through a target located at the detected distance with respect to the controlled vehicle, the target having a predetermined height above a predetermined reference point, the predetermined height of the target being unchanged irrespective of change in the detected distance; and

a first adjuster configured to adjust the direction of the optical axis of the headlight in the vertical direction so that the direction of the optical axis is matched with the determined first target direction.

2. A system according to claim 1, further comprising:

a vehicle-speed detector configured to detect a speed of the controlled vehicle; and

a height-adjusting unit configured to adjust the predetermined height of the target based on the detected speed of the controlled vehicle.

3. A system according to claim 2, wherein the height-adjusting unit is configured to reduce the predetermined height of the target with reduction in the detected speed of the vehicle and to increase the predetermined height of the target with increase in the detected speed of the vehicle.

4. A system according to claim 1, wherein the distance detector is configured to repeatedly sample the distance between the controlled vehicle and the other vehicle ahead thereof, further comprising:

an averaging unit configured to average a plurality of the detected samples of the distance over a predetermined period of time so as to obtain an averaged value of the distance, and

wherein the determiner is configured to determine the first target direction for the optical axis of the headlight in the vertical direction when it is assumed that the optical axis of the headlight passes through the target located at the averaged value of the distance with respect to the controlled vehicle.

5. A system according to claim 1, further comprising:

a driving condition detector configured to detect at least one driving condition of the controlled vehicle;

a driving mode detector configured to detect which driving mode the controlled vehicle operates in based on the detected driving condition; and

a height-adjusting unit configured to adjust the predetermined height of the target based on the detected driving mode of the controlled vehicle.

6. A system according to claim 5, further comprising:

an averaging unit configured to average a plurality of the detected samples of the distance over a predetermined period of time so as to obtain an averaged value of the distance; and

a limit determining unit configured to determine whether to limit the averaging of the detected samples of the distance by the averaging unit according to the detected driving mode of the controlled vehicle.

7. A system according to claim 1, further comprising:

a driving condition detector configured to detect at least one driving condition of the controlled vehicle;

a driving mode detector configured to detect which driving mode the controlled vehicle operates in based on the detected driving condition; and

a limit determining unit configured to determine whether to limit the adjusting of the direction of the optical axis of the headlight in the vertical direction by the first adjuster according to the detected driving mode of the controlled vehicle.

8. A system according to claim 1, further comprising:

a second adjuster configured to adjust the direction of the optical axis of the headlight in a horizontal direction in cooperation with the first adjuster.

9. A system according to claim 8, wherein the headlight consists of a pair of headlights mounted on both sides of a front end of the controlled vehicle, the determiner is configured to determine the first target direction for the optical axis of the headlight in the vertical direction when it is assumed that the optical axis of each of the paired headlights passes through a target located at the detected distance with respect to the controlled vehicle, and the first adjuster is configured to adjust the direction of the optical axis of each of the paired headlights in the vertical direction so that the direction of the optical axis is matched with the determined first target direction, further comprising:

a second adjuster configured to adjust the direction of the optical axis of the headlight in a horizontal direction orthogonal to the vertical direction so as to wider a distance between the optical axis of one of the paired headlights in the horizontal direction and that of the other thereof with the optical axis of each of the paired headlight being dipped by the first adjuster in the vertical direction.

10. A system according to claim 5, wherein the at least one driving condition of the controlled vehicle includes a light source of incoming light based on a plurality of images of a predetermined region ahead of the controlled vehicle.

11. A system according to claim 5, wherein the at least one driving condition of the controlled vehicle includes a type of a road on which the controlled vehicle is running.

12. A system according to claim 5, wherein the controlled vehicle operates in one of a plurality of the driving modes, the plurality of the driving modes include a town mode, a normal mode, a motorway mode, a turning mode, a passing mode, a overtaking mode, and a stopping mode,

the town mode representing a driving scene in which the controlled vehicle is estimated to be running in urban areas, the normal mode representing a driving scene in which the controlled vehicle is estimated to be running in a residential block,

the turning mode representing a driving scene in which the controlled vehicle is estimated to be turning.

the passing mode representing a driving scene in which the controlled vehicle is estimated to be passing an oncoming vehicle as the other vehicle,

the overtaking mode representing a driving scene in which the controlled vehicle is estimated to be overtaking a preceding vehicle as the other vehicle,

the stopping mode representing a driving scene in which the controlled vehicle is estimated to be stopping.