Device, system and method for calibration of camera and laser sensor

• US 9,470,548 B2
• Filed: 07/24/2013
• Issued: 10/18/2016
• Est. Priority Date: 01/31/2011
• Status: Active Grant

• Current Assignee: Agency For Defense Development (Government of The Republic of China)
• Original Assignee: Agency For Defense Development (Government of The Republic of China)
• Inventors: Ahn, Seong Yong, Choe, Tok Son, Park, Yong Woon, Lee, Won Seok
• Primary Examiner(s): Williams, Hezron E
• Assistant Examiner(s): Nguyen, Hoang
• Application Number:
  US13/949,622
• Publication Number:
  US 20130305805A1
• Time in Patent Office: 1,182 Days
• Field of Search: 73/17.9, 73/18.1, 702/94, 702/95, 702150-153
• US Class Current: 1/1
• CPC Class Codes: G01C 23/00 Combined instruments indicating more than one navigational value, e.g. for aircraft; Combined measuring devices for measuring two or more variables of movement, e.g. distance, speed or acceleration
• CPC Class Codes: G01S 17/08 for measuring distance only indirect measurement G01S17/46; active triangulation systems G01S17/48
• CPC Class Codes: G01S 17/87 Combinations of systems using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 7/497 Means for monitoring or calibrating

Abstract

Disclosed are a calibration device, a calibration system and a calibration method. The calibration device includes a camera configured to capture image information, a laser sensor configured to capture image information, a laser sensor configured to detect distance information, and a calibration module configured to perform a calibration of the camera and the laser sensor by obtaining a relation between the image information and the distance information, wherein the calibration module includes a plane member disposed to intersect a scanning surface of the laser sensor such that an intersection line is generated, and disposed within a capturing range by the camera so as to be captured by the camera, and a controller configured to perform coordinate conversions with respect to the image information and the distance information based on a ratio between one side of the plane member and the intersection line, and based on a plane member image included in the image information. Under these configurations, a calibration is performed through direct coordinate conversions with respect to image information and distance information.

Claims

1. A calibration device, comprising:

a camera configured to capture image information;

a laser sensor configured to detect distance information; and

a calibration module configured to perform a calibration of the camera and the laser sensor by obtaining a relation between the image information and the distance information,

wherein the calibration module comprises;

a plane member disposed to intersect a scanning surface of the laser sensor such that an intersection line is generated, and disposed within a capturing range by the camera so as to be captured by the camera, and a controller configured to perform coordinate conversions with respect to the image information and the distance information based on a ratio between one side of the plane member and the intersection line, and based on a plane member image included in the image information.

2. The calibration device of claim 1, wherein the one side of the plane member is disposed to be parallel to the scanning surface.

3. The calibration device of claim 2, wherein the plane member is formed in a triangle or a trapezoid having the one side as a bottom side.

4. The calibration device of claim 1, wherein the controller calculates second position data of an intersection line image corresponding to the intersection line, from the plane member image by using the ratio, and performs coordinate conversions based on the second position data, and first position data of the intersection line measured by the laser sensor.

5. The calibration device of claim 4, wherein the controller calculates a conversion matrix with respect to the image information and the distance information based on the first and second position data, and performs the coordinate conversions based on the conversion matrix.

6. A calibration system, comprising:

a camera configured to capture image information;

a laser sensor configured to detect distance information;

a calibration device having a plane member disposed within a capturing range by the camera and within a detection range by the laser sensor, and a controller configured to perform coordinate conversions with respect to the image information and the distance information based on an intersection line between a scanning surface of the laser sensor and the plane member; and

a driving device coupled to the plane member to change a posture of the plane member in at least one direction among roll, pitch and yaw directions.

7. The calibration system of claim 6, further comprising:

a posture detector configured to detect a posture of the plane member; and

a posture controller connected to the posture detector or the driving device, and configured to control the driving device such that one side of the plane member is parallel to the scanning surface of the laser sensor.

8. The calibration system of claim 7, wherein the plane member is formed in a triangle or a trapezoid having the one side as a bottom side.

9. The calibration system of claim 6, further comprising a supporting portion configured to support the driving device, and having a length variable so as to control a height of the plane member.

10. The calibration system of claim 6, wherein controller is configured to perform coordinate conversions with respect to the image information and the distance information based on a ratio between one side of the plane member and the intersection line, and based on a plane member image included in the image information.

11. The calibration system of claim 10, wherein the controller calculates second position data of an intersection line image corresponding to the intersection line, from the plane member image by using the ratio, and performs coordinate conversions based on the second position data, and first position data of the intersection line measured by the laser sensor.

12. A calibration method for performing coordinate conversions with respect to a camera configured to capture image information, and a laser sensor configured to detect distance information, the calibration method comprising:

detecting an intersection line between a plane member disposed within a detection range by the laser sensor and a scanning surface of the laser sensor;

calculating position data of an intersection line image captured by the camera, based on one preset side of the plane member, the intersection line, and a plane member image captured by the camera; and

calculating a conversion matrix which represents a position relation between the camera and the laser sensor, based on a position data of the intersection line image, and position data of the intersection line measured by the laser sensor.

13. The method of claim 12, wherein the calculation step, positions of laser points on the plane member image are acquired based on a ratio between one side of the plane member and the intersection line, and based on one side image corresponding to one side of the plane member and captured by the camera.

14. The method of claim 13, wherein the laser points indicate positions of pixels on the intersection line image, the pixels corresponding to two end points of the intersection line.

15. The method of claim 13, further comprising:

determining whether the number of the laser points corresponds to a reference value for calculating the conversion matrix; and

changing a posture of the plane member when the number of the laser points is less than the reference value.

16. The method of claim 15, wherein the posture of the plane member is changed in a condition that one side of the plane member is parallel to the scanning surface.