Image acquisition system and method for distance determination using an image recording system

• US 8,896,690 B2
• Filed: 04/10/2007
• Issued: 11/25/2014
• Est. Priority Date: 06/12/2006
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Muehlmann, Karsten, Wuerz-Wessel, Alexander
• Primary Examiner(s): Nguyen, Thuong
• Application Number:
  US12/300,731
• Publication Number:
  US 20090322872A1
• Time in Patent Office: 2,786 Days
• Field of Search: 348/118, 348/148, 348/142, 382/106, 382/154, 382/210
• US Class Current: 348/142
• CPC Class Codes: G01S 11/12 using electromagnetic waves other than radio waves
• CPC Class Codes: G06T 7/579 from motion
• 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: G06V 20/584 of vehicle lights or traffic lights
• CPC Class Codes: H04N 23/70 Circuitry for compensating brightness variation in the scene

Abstract

A vehicle-based image acquisition system having an image sensor that has a characteristic curve assembled from linear segments. The system includes an arrangement for determining the distance of luminous objects imaged by the image sensor.

Claims

1. A method for determining the distance between an image acquisition system encompassing an image sensor and a luminous object moving relative to the image acquisition system, the method comprising:

generating, using the image sensor, an image of surroundings of the image sensor encompassing a luminous object;

after the image has been generated, selecting at least one luminous object of interest from the image generated by the image sensor;

for the selected luminous object, sensing a tailing of the image of the selected luminous object, where tailing occurs as a consequence of control properties of the image sensor and a relative velocity between the image sensor and the luminous object; and

associating a magnitude of the tailing with a distance value;

wherein from an acquisition time interval of the images of the sensor, and from a change in a relative size of the object in the image, a time to adjacency is determined based on an acquisition time interval of the images and a scale change.

2. The method as recited in claim 1, wherein the extent of the tailing is sensed by way of a window enclosing the image of the luminous object.

3. The method as recited in claim 1, wherein a greatest tailing is associated with a shortest distance value.

4. The method as recited in claim 1, wherein a risk assessment is carried out as a function of the tailing.

5. The method as recited in claim 1, wherein the extent of the tailing is sensed by way of a window enclosing the image of the luminous object, wherein a greatest tailing is associated with a shortest distance value, and wherein a risk assessment is carried out as a function of the tailing.

6. A method for determining the distance between an image acquisition system encompassing an image sensor and a luminous object moving relative to the image acquisition system, the method comprising:

generating, using the image sensor, an image of surroundings of the image sensor encompassing a luminous object;

selecting a luminous object of interest from the image generated by the image sensor;

for the selected object, sensing a tailing of the image of the luminous object, which tailing occurs as a consequence of control properties of the image sensor and a relative velocity between the image sensor and the luminous object; and

associating a magnitude of the tailing with a distance value;

wherein from an acquisition time interval of the images of the sensor, and from a change in a relative size of the object in the image, a time to adjacency is determined according to the following equation;

tta=Δ

t/(sc−

1.0),

where

tta=time to adjacency;

Δ

t=acquisition time interval of the images;

sc=scale change (change in relative size of the object in the image).

7. The method as recited in claim 6, wherein the extent of the tailing is sensed by way of a window enclosing the image of the luminous object.

8. The method as recited in claim 6, wherein a greatest tailing is associated with a shortest distance value.

9. The method as recited in claim 6, wherein a risk assessment is carried out as a function of the tailing.

10. The method as recited in claim 6, wherein the extent of the tailing is sensed by way of a window enclosing the image of the luminous object, wherein a greatest tailing is associated with a shortest distance value, and wherein a risk assessment is carried out as a function of the tailing.

11. An image acquisition system for determining the distance to a luminous object moving relative to the image acquisition system, comprising:

an image sensor for generating an image of surroundings of the image sensor encompassing a luminous object and selecting at least one luminous object of interest from the generated image after the image has been generated;

wherein for the selected luminous object, a tailing of the image of the selected luminous object, where tailing occurs as a consequence of control properties of the image sensor and a relative velocity between the image sensor and the luminous object is sensed, and

wherein a magnitude of the tailing is associated with a distance value;

wherein from an acquisition time interval of the images of the sensor, and from a change in a relative size of the object in the image, a time to adjacency is determined based on an acquisition time interval of the images and a scale change.

12. The system of claim 11, wherein the extent of the tailing is sensed by a window enclosing the image of the luminous object.

13. The system of claim 11, wherein a greatest tailing is associated with a shortest distance value.

14. The system of claim 11, wherein a risk assessment is performed as a function of the tailing.

15. The system of claim 11, wherein the extent of the tailing is sensed by a window enclosing the image of the luminous object, wherein a greatest tailing is associated with a shortest distance value, and wherein a risk assessment is performed as a function of the tailing.

16. An image acquisition system for determining the distance to a luminous object moving relative to the image acquisition system, comprising:

an image sensor for generating an image of surroundings of the image sensor encompassing a luminous object and selecting a luminous object of interest from the generated image;

wherein for the selected object, a tailing of the image of the luminous object, which tailing occurs as a consequence of control properties of the image sensor and a relative velocity between the image sensor and the luminous object is sensed,

wherein a magnitude of the tailing is associated with a distance value, and

wherein from an acquisition time interval of the images of the sensor, and from a change in a relative size of the object in the image, a time to adjacency is determined according to the following equation;

tta=Δ

t/(sc−

1.0), where tta=time to adjacency, Δ

t=acquisition time interval of the images; and

sc=scale change (change in relative size of the object in the image).

17. The system of claim 16, wherein the extent of the tailing is sensed by a window enclosing the image of the luminous object.

18. The system of claim 16, wherein a greatest tailing is associated with a shortest distance value.

19. The system of claim 16, wherein a risk assessment is performed as a function of the tailing.

20. The system of claim 16, wherein the extent of the tailing is sensed by a window enclosing the image of the luminous object, wherein a greatest tailing is associated with a shortest distance value, and wherein a risk assessment is performed as a function of the tailing.