Traffic signal recognition apparatus

Patent metadata

Field	Value
Publication number	US-9389093-B2
Application number	US-201414782072-A
Country	US
Kind code	B2
Filing date	Feb 25, 2014
Priority date	Apr 4, 2013
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

A traffic signal recognition apparatus includes a control device that executes: a captured image acquisition function which acquires a captured image around an own vehicle; an own vehicle position acquisition function which acquires a current position of the own vehicle; a target traffic signal specifying function which refers to map information to specify a traffic signal to be targeted in a traveling link for the own vehicle, the traffic signal data including position information about the traffic signal related to the traveling link; a traffic signal image area extraction function which extracts an image area of the traffic signal on the basis of the position information about the traffic signal and image capturing property information about the camera; and a traffic signal content recognition function which recognizes a traffic signal content of the traffic signal on the basis of an image of the traffic signal in the image area.

First claim

The invention claimed is:

1. A traffic signal recognition apparatus comprising:
a captured image acquisition unit configured to acquire a captured image around an own vehicle from an image capturing unit on-vehicle;
an own vehicle position acquisition unit configured to acquire a current position of the own vehicle;
a target traffic signal specifying unit configured to:
refer to map information;
calculate a next traveling link by using a traveling link, the traveling link being a link to which the current position of the own vehicle belongs, the next traveling link being a link to which the own vehicle travels next after the traveling link; and

specify a traffic signal to be targeted when traveling on the next traveling link;

a traffic signal image area extraction unit configured to extract an image area of the traffic signal from the captured image by using position information about the specified traffic signal and image capturing property information about the image capturing unit; and
a traffic signal content recognition unit configured to recognize a traffic signal content of the traffic signal by using an image of the traffic signal included in the extracted image area, wherein
the map information includes traveling link data and traffic signal data,
the traveling link data includes:
the traveling link which is defined for each traffic lane by a directed link including a start point, an end point and an up direction or a down direction;
a connected link which is connected with each of the start point and the end point of the directed link; and

traveling direction information which specifies a traveling direction including straight ahead or right turn or left turn,
the traveling link, the connected link and the traveling direction information being related to one another,

the traffic signal data is related to the traveling link, and
the traffic signal data includes the position information about the traffic signal to be targeted when traveling on the traveling link.

2. The traffic signal recognition apparatus according to claim 1 , wherein the target traffic signal specifying unit configured to
refer to the traveling link data for the own vehicle to travel,
calculate the next traveling link when a distance between the own vehicle and the end point of the directed link related to the traveling link is shorter than a predetermined value, and,
specify the traffic signal to be targeted when traveling on the next traveling link.

3. The traffic signal recognition apparatus according to claim 1 , wherein
the own vehicle position acquisition unit is configured to acquire an attitude of the own vehicle at the current position and
the traffic signal image area extraction unit is configured to extract the image area of the traffic signal from the captured image in accordance with the acquired attitude of the own vehicle.

4. The traffic signal recognition apparatus according to claim 1 , wherein
one item of the traveling link data is respectively related to one item of the traffic signal data.

5. The traffic signal recognition apparatus according to claim 1 , wherein
the image capturing unit comprises a moving mechanism which is configured to vary an imaging direction of the image capturing unit and
the moving mechanism is configured to vary the imaging direction of the image capturing unit in accordance with a position of the image area of the traffic signal in the captured image.

6. The traffic signal recognition apparatus according to claim 1 , wherein
the image capturing unit has a zoom function, and
the zoom function of the image capturing unit includes a control function of an image capturing magnification which is controlled on the basis of a surface ratio of the image area of the traffic signal with respect to the image area of the captured image.

7. A traffic signal recognition apparatus comprising:
a camera which is mounted on an own vehicle;
a position detection device; and
a control device, wherein
the camera is configured to capture an image around the own vehicle,
the position detection device is configured to detect a current position of the own vehicle,
the control device is configured to:
refer to map information stored in a database;
calculate a next traveling link by using a traveling link, the travelling link being a link to which the detected current position of the own vehicle belongs, the next travelling link being a link to which the own vehicle travels next after the traveling link;
specify a traffic signal to be targeted when traveling on the next traveling link;

extract an image area of the traffic signal from the captured image by using position information about the specified traffic signal and image capturing property information about the camera; and
recognize a traffic signal content of the traffic signal by using an image of the traffic signal included in the extracted image area,

the map information includes traveling link data and traffic signal data,
the traveling link data includes:
a traveling link which is defined for each traffic lane by a directed link including a start point, an end point and an up direction or a down direction;
a connected link which is connected with each of the start point and the end point of the directed link; and
traveling direction information which specifies a traveling direction including straight ahead or right turn or left turn,
the traveling link, the connected link and the traveling direction information being related to one another,

the traffic signal data is related to the traveling link, and
the traffic signal data includes the position information about the traffic signal to be targeted when traveling on the traveling link.

Assignees

• Nissan Motor

Inventors

• Kojo Naoki

Classifications

• H04N23/69

  Control of means for changing angle of the field of view, e.g. optical zoom objectives or electronic zooming · CPC title

• G08G1/09626

  where the origin of the information is within the own vehicle, e.g. a local storage device, digital map · CPC title

• G01C21/3602 Primary

  Input other than that of destination using image analysis, e.g. detection of road signs, lanes, buildings, real preceding vehicles using a camera · CPC title

• G08G1/09623

  Systems involving the acquisition of information from passive traffic signs by means mounted on the vehicle (G08G1/0967 takes precedence) · CPC title

• G06T2207/30256

  Lane; Road marking · CPC title