Tunnel detecting device for vehicle and light control device for vehicle

• US 20060159309A1
• Filed: 01/12/2006
• Published: 07/20/2006
• Est. Priority Date: 01/14/2005
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Tsukamoto, Takeshi
• Granted Patent: US 7,646,888 B2
• Time in Patent Office: Days
• 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 2300/314 Ambient light
• CPC Class Codes: B60Q 2300/337 Tunnels or bridges

Abstract

A vehicle tunnel detecting device includes an image pickup unit for picking up images of a forward area and an obliquely upper area with respect to a travel direction of a vehicle, an obliquely upper area brightness reduction detecting unit for judging whether an average brightness of the images of the obliquely upper area with respect to the travel direction picked up by the image pickup unit is lower than a predetermined value, a brightness difference detecting unit for calculating a difference in average brightness between the images of the forward and obliquely upper areas achieved by the image pickup unit when it is judged by the obliquely upper area brightness reduction detecting unit that the average brightness of the image of the obliquely upper area is lower than the predetermined value, and a tunnel identifying unit for identifying a tunnel when the difference in average brightness between the image of the forward area and the image of the obliquely upper area that is calculated by the brightness difference detecting unit is lower than a predetermined value.

Claims

1. A vehicle tunnel detecting device comprising:

an image pickup unit for picking up images of a forward area and an obliquely upper area with respect to a travel direction of a vehicle;

an obliquely upper area brightness reduction detecting unit for judging whether an average brightness of the images of the obliquely upper area with respect to the travel direction picked up by the image pickup unit is lower than a predetermined value;

a brightness difference detecting unit for calculating a difference in average brightness between the images of the forward and obliquely upper areas achieved by the image pickup unit when it is judged by the obliquely upper area brightness reduction detecting unit that the average brightness of the image of the obliquely upper area is lower than the predetermined value; and

a tunnel identifying unit for identifying a tunnel when the difference in average brightness between the image of the forward area and the image of the obliquely upper area that is calculated by the brightness difference detecting unit is lower than a predetermined value.

2. A vehicle tunnel detecting device comprising:

an image pickup unit for picking up an image of an obliquely upper area with respect to a travel direction of a vehicle;

an obliquely upper area brightness reduction detecting unit for judging whether an average brightness of the image of the obliquely upper area with respect to the travel direction which is achieved by the image pickup unit is lower than a predetermined value;

a high brightness area extracting unit for binarizing the image of the obliquely upper area with respect to the travel direction which is achieved by the image pickup unit when it is judged by the obliquely upper area brightness reduction detecting unit that the average brightness of the image of the obliquely upper area is lower than the predetermined value, and extracting a high brightness area having a brightness that is higher than a predetermined brightness; and

a tunnel identifying unit for identifying a tunnel when it is judged by the high brightness area extracting unit that at least one of a size and number of high brightness areas having a predetermined brightness or more satisfies a predetermined condition.

3. A vehicle tunnel detecting device comprising:

an image pickup unit for picking up images of a forward area and an obliquely upper area with respect to a travel direction of a vehicle;

an obliquely upper area brightness reduction detecting unit for judging whether an average brightness of the images of the obliquely upper area achieved by the image pickup with respect to the travel direction unit is lower than a predetermined value;

a high brightness area extracting unit for binarizing the image of the obliquely upper area with respect to the travel direction when it is judged by the obliquely upper area brightness reduction detecting unit that the average brightness of the image of the obliquely upper area is lower than a predetermined value, and extracting a high brightness area having a brightness higher than predetermined brightness;

a brightness difference detecting unit for calculating a difference in average brightness between the image of the forward area and the image of the obliquely upper area which are picked up the image pickup unit when it is judged that at least one of a size and a number of high brightness areas having predetermined brightness or more extracted by the high brightness area extracting unit satisfies a predetermined condition; and

a tunnel identifying unit for identifying a tunnel when the difference in the average brightness between the image of the forward area and the image of the obliquely upper area that is calculated by the brightness difference detecting unit is lower than a predetermined value.

4. A vehicle light control device using a vehicle tunnel detecting device comprising:

an image pickup unit for picking up images of a forward area and an obliquely upper area with respect to a travel direction of a vehicle;

an obliquely upper area brightness reduction detecting unit for judging whether an average brightness of the images of the obliquely upper area with respect to the travel direction by the image pickup unit is lower than a predetermined value;

a brightness difference detecting unit for calculating a difference in average brightness between the images of the forward and obliquely upper areas achieved by the image pickup unit when it is judged by the obliquely upper area brightness reduction detecting unit that the average brightness of the image of the obliquely upper area is lower than the predetermined value; and

a tunnel identifying unit for identifying a tunnel when the difference in average brightness between the image of the forward area and the image of the obliquely upper area that is calculated by the brightness difference detecting unit is lower than a predetermined value, wherein the vehicle light control device turns on a vehicle lamp when the tunnel identifying unit identifies a tunnel.

7. The vehicle light control device according to claim 4, wherein a CPU provided with appropriate processing comprises the obliquely upper area brightness reduction detecting unit, the brightness difference detecting unit and the tunnel identifying unit.

5. A vehicle light control device using a vehicle tunnel detecting device comprising:

an image pickup unit for picking up an image of an obliquely upper area with respect to a travel direction of a vehicle;

an obliquely upper area brightness reduction detecting unit for judging whether the average brightness of the image of the obliquely upper area with respect to the travel direction which is achieved by the image pickup unit is lower than a predetermined value;

a high brightness area extracting unit for binarizing the image of the obliquely upper area with respect to the travel direction which is achieved by the image pickup unit when it is judged by the obliquely upper area brightness reduction detecting unit that the brightness of the image of the obliquely upper area is lower than the predetermined value, and extracting a high brightness area having a brightness that is higher than predetermined brightness; and

a tunnel identifying unit for identifying a tunnel when it is judged by the high brightness area extracting unit that at least one of a size and number of high brightness areas satisfies a predetermined condition, wherein the vehicle light control device turns on a vehicle lamp when the tunnel identifying unit identifies a tunnel.

6. A vehicle light control device using a vehicle tunnel detecting device comprising:

an image pickup unit for picking up images of a forward area and an obliquely upper area with respect to a travel direction of a vehicle;

an obliquely upper area brightness reduction detecting unit for judging whether an average brightness of the images of the obliquely upper area with respect to the travel direction by the image pickup unit is lower than a predetermined value;

a high brightness area extracting unit for binarizing the image of the obliquely upper area with respect to the travel direction which is picked up by the image pickup unit when it is judged by the obliquely upper area brightness reduction detecting unit that average brightness of the image of the obliquely upper area is lower than a predetermined value, and extracting a high brightness area whose brightness is higher than predetermined brightness;

a brightness difference detecting unit for calculating a difference in an average brightness between the image of the forward area and the image of the obliquely upper area which are picked up the image pickup unit when it is judged that at least one of the size and number of high brightness areas having predetermined brightness or more extracted by the high brightness area extracting unit satisfies a predetermined condition; and

a tunnel identifying unit for identifying a tunnel when the difference in average brightness between the image of the forward area and the image of the obliquely upper area that is calculated by the brightness difference detecting unit is lower than a predetermined value, wherein the vehicle light control device turns on a vehicle lamp when the tunnel identifying unit of the vehicle tunnel detecting device identifies a tunnel.