Distance measuring apparatus and method employing two image taking devices having different measurement accuracy

• US 6,483,536 B2
• Filed: 11/02/2001
• Issued: 11/19/2002
• Est. Priority Date: 11/17/2000
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Aoyama, Chiaki
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): ANDREA, BRIAN K
• Application Number:
  US09/985,432
• Publication Number:
  US 20020060783A1
• Time in Patent Office: 382 Days
• Field of Search: 356/3-1-, 901/47, 250/559.31, 250/559.33, 348/139
• US Class Current: 348/139
• CPC Class Codes: G01C 11/02 Picture taking arrangements specially adapted for photogrammetry or photographic surveying, e.g. controlling overlapping of pictures
• CPC Class Codes: G01C 3/02 Details
• 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 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/481 Constructional features, e.g. arrangements of optical elements
• CPC Class Codes: G05D 1/0248 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0251 extracting 3D information from a plurality of images taken from different locations, e.g. stereo vision stereoscopic image analysis H04N13/00; depth recovery from images G06T7/593

Abstract

A distance measuring apparatus is disclosed, which measures the entire image of a target object by employing a light-section method within a short time, without assigning any specific feature to light beams having a beam form obtained by passing through slits. The apparatus comprises a device for simultaneously emitting such light beams; first and second image taking devices for taking an image obtained by light reflected by the target object, where the distance between the first image taking device and the beam emitting device is relatively short while the distance between the first image taking device and the beam emitting device is relatively long; a section for estimating the distance to the target object based on the image taken by the first image taking device; and a section for determining the distance based on the estimated result and on the image taken by the second image taking device.

Claims

1. A distance measuring apparatus for measuring a distance to a target object by using a light-section method, comprising:

a beam emitting device for simultaneously emitting a plurality of light beams towards the target object, each beam having a beam form obtained by passing through a slit;

a first image taking device for taking an image obtained by light reflected by the target object, where the distance between the first image taking device and the beam emitting device is relatively short so as to obtain a wide distance area;

a second image taking device for taking an image obtained by light reflected by the target object, where the distance between the second image taking device and the beam emitting device is relatively long so as to obtain a high measurement accuracy of the distance;

a distance estimating section for estimating the distance to the target object based on the image taken by the first image taking device; and

a distance determining section for determining the distance to the target object based on the estimated result output from the distance estimating section and on the image taken by the second image taking device.

2. A distance measuring apparatus as claimed in claim 1, wherein the beam emitting device is positioned between the first image taking device and the second image taking device.

3. A distance measuring apparatus as claimed in claim 1, wherein the beam emitting device includes a diffraction grating for obtaining said plurality of light beams.

4. A distance measuring apparatus as claimed in claim 1, wherein said plurality of light beams are laser beams.

5. A distance measuring apparatus as claimed in claim 1, wherein the beam emitting device includes a beam diffusing element for diffusing a beam in a single plane so as to have said beam form.

6. A distance measuring apparatus as claimed in claim 5, wherein the beam diffusing element has a cylindrical lens.

7. A distance measuring apparatus as claimed in claim 1, wherein each of the first image taking device and the second image taking device comprises an interlaced scanning CCD camera.

8. A self-controlled robot having a distance measuring apparatus as claimed in claim 1.

9. A self-controlled robot as claimed in claim 8, wherein the self-controlled robot is a bipedal robot having two legs.

10. A self-controlled robot as claimed in claim 9, wherein:

the distance estimating section has a section for estimating the height of the target object based on the image taken by the first image taking device; and

the self-controlled robot comprises an action plan determining section for determining an action plan of the robot based on the estimated result output from the distance estimating section; and

the distance determining section has a section for determining a landing position of a leg of the robot based on the action plan, the estimated result output from the distance estimating section, and the image taken by the second image taking section.

11. A distance measuring method of measuring a distance to a target object by using a light-section method, comprising:

a beam emitting step of simultaneously emitting a plurality of light beams towards the target object, each beam having a beam form obtained by passing through a slit;

a first image taking step of taking an image obtained by light reflected by the target object, where the distance between the point where the image is taken and the position where the beams are emitted is relatively short so as to obtain a wide distance area;

a second image taking step of taking an image obtained by light reflected by the target object, where the distance between the point where the image is taken and the position where the beams are emitted is relatively long so as to obtain a high measurement accuracy of the distance;

a distance estimating step of estimating the distance to the target object based on the image taken in the first image taking step; and

a distance determining step of determining the distance to the target object based on the estimated result obtained in the distance estimating step and on the image taken in the second image taking step.

12. A distance measuring method as claimed in claim 11, wherein the position where the beams are emitted is positioned between the point where the image is taken in the first image taking step and the point where the image is taken in the second image taking step.

13. A distance measuring method as claimed in claim 11, wherein said plurality of light beams are laser beams.

14. A distance measuring method as claimed in claim 11, wherein the beam emitting step includes a beam diffusing step of diffusing a beam in a single plane so as to have said beam form.