Method for detecting an object in an environmental region of a motor vehicle by means of a camera system of the motor vehicle, camera system and motor vehicle

• US 9,340,156 B2
• Filed: 04/14/2015
• Issued: 05/17/2016
• Est. Priority Date: 04/14/2014
• Status: Active Grant

• Current Assignee: Connaught Electronics Limited (Valeo SE)
• Original Assignee: Connaught Electronics Limited (Valeo SE)
• Inventors: Jones, Edward, O'Cualain, Diarmad, Glavin, Martin
• Primary Examiner(s): Kim, Hee-Yong
• Application Number:
  US14/686,160
• Publication Number:
  US 20150291097A1
• Time in Patent Office: 399 Days
• Field of Search: 348/148
• US Class Current: 1/1
• CPC Class Codes: B60R 2300/10 characterised by the type of camera system used
• CPC Class Codes: G06V 10/145 Illumination specially adapted for pattern recognition, e.g. using gratings
• CPC Class Codes: G06V 20/56 exterior to a vehicle by using sensors mounted on the vehicle
• CPC Class Codes: G06V 20/58 Recognition of moving objects or obstacles, e.g. vehicles or pedestrians; Recognition of traffic objects, e.g. traffic signs, traffic lights or roads
• CPC Class Codes: H04N 7/183 for receiving images from a single remote source

Abstract

A method for detecting an object in an environmental region of a motor vehicle by a camera system of the motor vehicle is disclosed. A first image of the environmental region is provided by a camera of the camera system with illumination of the environmental region using a light source of the motor vehicle such that a shadow of the object caused by the illumination is depicted in the first image. A second image of the environmental region is also provided by the camera in an inactive state of the light source, in which the illumination is omitted. Then, a subtraction image is generated by subtracting one of the images from the other image by an image processing device of the camera system. Then, an edge image is generated from the subtraction image, and the object is detected based on edges of the edge image by the image processing device.

Claims

1. A method for detecting an object in an environmental region of a motor vehicle by a camera system of the motor vehicle, the method comprising:

providing a first image of the environmental region by a camera of the camera system with illumination of the environmental region using at least one light source of the motor vehicle, such that a shadow of the object caused by the illumination is depicted in the first image;

providing a second image of the environmental region by the camera in an inactive state of the light source, wherein in the second image the illumination is omitted;

providing a subtraction image by subtracting one of the first and second images from another of the first and second images by an image processing device of the camera system; and

providing an edge image from the subtraction image and detecting the object based on edges of the edge image by the image processing device, the edge image associated with shadows in the first image caused by illumination of the at least one light source,

wherein the light source is alternately switched with a predetermined switching frequency greater than 75 Hz between the inactive state and an active state, in which the light source illuminates the environmental region, wherein a sequence of images of the environmental region is provided by the camera and a frame rate of the camera is adjusted depending on the switching frequency.

2. The method according to claim 1, wherein in detecting the object, a differentiation is made between an obstacle raised above ground and a ground marking.

3. The method according to claim 1, wherein a distance of the detected object from the motor vehicle is calculated based on the edge image considering an internal and/or external orientation of the camera, by the image processing device.

4. The method according to claim 1, wherein based on at least one traveling parameter of the motor vehicle at least based on a current steering angle of the motor vehicle, a prospective trajectory of the motor vehicle is determined and the detected object is classified depending on the prospective trajectory.

5. The method according to claim 4, wherein depending on the classification of the object, a warning signal is output by the image processing device to warn the of the object.

6. The method according to claim 3, wherein depending on the distance, a warning signal is output by the image processing device, to warn the drive of the object.

7. The method according to claim 6, wherein the warning signal is one of an acoustic signal and/or a visual signal and/or a haptic signal and is output by the image processing device to warn the driver of the object (7).

8. The method according to claim 1, wherein the environmental region is illuminated by at least one of one taillight and one headlight, as the light source of the motor vehicle.

9. The method according to claim 1, wherein a third image of the environmental region with illumination of the environmental region with at least a second light source disposed in a distance to the at least one light source, in the inactive state of the at least one light source is provided by the camera, wherein a second subtraction image is provided from the first and the third image by the image processing device and the edge image is generated based on both the subtraction image and the second subtraction image.

10. A camera system for a motor vehicle comprising

at least one camera for providing images of an environmental region of the motor vehicle;

a light source for illuminating the environmental region wherein the light source is alternately switched with a predetermined switching frequency greater than 75 Hz between the inactive state and an active state, wherein a sequence of images of the environmental region is provided by the camera and a frame rate of the camera is adjusted depending on the switching frequency; and

an image processing device for detecting an object in the environmental region based on the images,

wherein the camera system is adapted to perform a method comprising;

providing a first image of the environmental region by a camera of the camera system with illumination of the environmental region using at least one light source of the motor vehicle such that a shadow of the object caused by the illumination is depicted in the first image;

providing a second image of the environmental region by the camera in an inactive state of the light source, wherein in the second image the illumination is omitted;

providing a subtraction image by subtracting one of the first and second images from another of the first and second images by an image processing device of the camera system;

providing an edge image from the subtraction image and detecting the object based on edges of the edge image by the image processing device, the edge image associated with the shadows in the first image caused by illumination of the at least one light source.

11. The camera system according to claim 10, wherein the camera system includes a lighting control unit for controlling the light source.

12. The camera system according to claim 10, wherein the light source includes a high-pressure gas discharge lamp and/or a xenon lamp.

13. The camera system according to claim 10, wherein the light source includes at least one light emitting diode.

14. A motor vehicle equipped with a camera system as claimed in claim 10.