Apparatus for recognizing environment

• US 20030026455A1
• Filed: 07/31/2002
• Published: 02/06/2003
• Est. Priority Date: 08/03/2001
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Takahashi, Hiroshi, Watanabe, Seigo
• Granted Patent: US 6,956,959 B2
• Time in Patent Office: Days
• US Class Current: 382/104
• CPC Class Codes: B60W 30/09 Taking automatic action to avoid collision, e.g. braking and steering
• CPC Class Codes: G01S 11/12 using electromagnetic waves other than radio waves
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/30261 Obstacle
• CPC Class Codes: G06T 7/254 involving subtraction of images

Abstract

An apparatus for recognizing an environment includes imaging unit (10) for picking up surroundings of a vehicle equipped with the apparatus so as to obtain a surrounding image, filter processing unit (20) for providing filter processing to the surrounding image for each predetermined sampling interval so as to obtain a process image and edge information, processed information memorizing unit (30) for memorizing the process image, image finite differentiating unit (40) for obtaining a difference image between the process image and a process image before an arbitrary sampling interval, frequency accumulating unit (50) for accumulating the number of moving pixels for each moving direction based on the edge information and the difference image so as to obtain a cumulative value, and determining unit (60) for performing determination of a surrounding environment in accordance with the cumulative value of the frequency accumulating unit (50).

Claims

1. An apparatus for recognizing an environment, comprising:

an imaging unit, which is attached to a vehicle, for picking up surroundings of the vehicle so as to obtain a surrounding image;

a filter processing unit for providing a filter processing to the surrounding image for each predetermined sampling interval so as to obtain a process image and an edge information;

a processed information memorizing unit for memorizing the process image;

an image finite differentiating unit for obtaining a difference image between the process image and a process image before an arbitrary sampling interval;

a frequency accumulating unit for accumulating the number of moving pixels for each moving direction based on the edge information and the difference image, and for obtaining a cumulative value; and

a determining unit for performing a determination of a surrounding environment in response to the cumulative value of the frequency accumulating unit.

2. The apparatus according to claim 1,

wherein the filter processing unit provides filter processing with a side control effect to the surrounding image, and detects the edge information constituted of a pixel position of an edge and a change type of a pixel value at the pixel position.

3. The apparatus according to claim 2,

wherein the filter processing unit provides the filter processing with a side control effect to the surrounding image so as to obtain the process image, thereafter a pixel position where a sign of a pixel value of an adjacent pixel in an arbitrary direction is reversed is used as a pixel position of the edge from the process image, and

wherein the filter processing unit differentiates between a case where the sign is reversed from a positive to a negative and a case where the sign is reversed from a negative to a positive so as to form the change type of the pixel value.

4. The apparatus according to claim 2,

wherein the frequency accumulating unit detects a moving direction of the pixel position by the sign of the pixel value of the difference image at the pixel position of the edge information and the change type of the pixel value, and

wherein the frequency accumulating unit calculates a cumulative value of the number of pixels having an arbitrary moving direction for each moving velocity range.

5. The apparatus according to claim 1,

wherein the determining unit determines whether or not an object approaches the vehicle based on the cumulative value obtained by the frequency accumulating unit, and

wherein at least one of control amounts of a brake and steering and a warning level is decided in accordance with the velocity of the object determined as approaching.

6. The apparatus according to claim 4,

wherein the determining unit changes a searching range and a processing range of at least one of a vehicle-mounted camera and radar based on both the edge information and the cumulative value.

7. A method for recognizing an environment, comprising:

picking up surroundings of the vehicle so as to obtain a surrounding image;

providing a filter processing to the surrounding image for each predetermined sampling interval so as to obtain a process image and an edge information;

memorizing the process image;

obtaining a difference image between the process image and a process image before an arbitrary sampling interval;

accumulating the number of moving pixels for each moving direction based on the edge information and the difference image so as to obtain a cumulative value; and

performing a determination of a surrounding environment in accordance with the cumulative value.

8. An apparatus for recognizing an environment, comprising:

imaging means, which is attached to a vehicle, for picking up surroundings of the vehicle so as to obtain a surrounding image;

filter processing means for providing a filter processing to the surrounding image for each predetermined sampling interval so as to obtain a process image and an edge information;

processed information memorizing means for memorizing the process image;

image finite differentiating means for obtaining a difference image between the process image and a process image before an arbitrary sampling interval;

frequency accumulating means for accumulating the number of moving pixels for each moving direction based on the edge information and the difference image, and for obtaining a cumulative value; and

determining means for performing a determination of a surrounding environment in response to the cumulative value of the frequency accumulating means.