Positional deviation detecting device for a mobile body and position correcting apparatus for a working machine mounted on a mobile body

• US 6,041,274 A
• Filed: 04/21/1998
• Issued: 03/21/2000
• Est. Priority Date: 04/21/1997
• Status: Expired due to Term

• Current Assignee: Murata Machinery Limited (Muratec)
• Original Assignee: Shinko Electric Industries Company Limited (Fujitsu Limited)
• Inventors: Nakai, Yutaka, Miura, Kouji, Onishi, Masanori, Murata, Masanao, Sugino, Tsukasa, Nakagawa, Susumu, Yasuda, Katsumi
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): ARTHUR JEANGLAUDE, GERTRUDE
• Application Number:
  US09/063,409
• Time in Patent Office: 700 Days
• Field of Search: 701/26, 701/28, 701/202, 701/207, 701/210, 701/214, 701/300, 180/168, 180/169, 318/580, 318/587, 901/1, 901/3
• US Class Current: 701/26
• CPC Class Codes: G01B 11/005 coordinate measuring machines
• CPC Class Codes: G01B 21/04 by measuring coordinates of points
• CPC Class Codes: G05D 1/0234 using optical markers or beacons optical beacons per se G01S1/70

Abstract

A pickup sensor for picking up an image on a floor is installed on a mobile body with a working machine mounted thereon in order to correct for the position deviation of a working machine due to possible deviation in the stop position of a mobile body to always ensure accurate working without increasing the working time of the overall system at the time of stopping the mobile body at a predetermined position and allowing said working machine to perform predetermined operation according to previously given teaching data. At the time the teaching data is given, the pickup sensor picks up an image (reference picked image) including a regular pattern and a predetermined identification mark formed on a floor. At the time the working machine works, the pickup sensor also picks up an image (on-pause picked image) on the floor surface at the stop position. The reference picked image is compared with the on-pause picked image based on the position of the identification mark, and the teaching data of the working machine is corrected on the basis of the comparison result. This correction does not involve the operation of the movable portions of the working machine or the like and can be accomplished by using an operation switching time which exists between the time when the mobile body has stopped and the time the working machine initiates an operation.

Claims

1. A position correcting apparatus for a working machine mounted on a mobile body for stopping said mobile body at a predetermined work position on a floor with a regular pattern formed thereon, and allowing said working machine to perform a predetermined operation according to teaching data, previously prepared and given to said working machine with said mobile body stopped at a reference stop position at said work position, comprising:

image pickup means, provided on said mobile body side at a position near said floor, for picking up an image on said floor where said mobile body stops;

reference picked image acquiring means for, at a time of giving said teaching data to said working machine, for acquiring a reference picked image including an image of said regular pattern and an image of a identification mark provided on said floor in vicinity of said predetermined work position, both acquired by said image pickup means with said mobile body stopped at said reference stop position of said work position;

on-pause picked image acquiring means for acquiring an on-pause picked image including images of said regular pattern and said identification mark acquired by said image pickup means at a stop position of said mobile body when stopped; and

teaching data correction means for comparing said regular pattern in said reference picked image, obtained by said reference picked image acquiring means, with said regular pattern in said on-pause picked image, obtained by said on-pause picked image acquiring means, based on a position of said identification mark, and correcting said teaching data of said working machine based on a result of the comparison.

2. The position correcting apparatus for a working machine according to claim 1, wherein said teaching data correction means compares predetermined position information obtained from said regular pattern in said reference picked image with predetermined position information obtained from said regular pattern in said on-pause picked image, and corrects said teaching data of said working machine based on a result of the comparison.

3. The position correcting apparatus for a working machine according to claim 1, wherein said teaching data correction means compares image information of said regular pattern in said reference picked image with image information of said regular pattern in said on-pause picked image, and corrects said teaching data of said working machine based on a result of the comparison.

4. The position correcting apparatus for a working machine according to any one of claims 1 to 3, wherein said floor with said regular pattern is made of a punching member or a grating member.

5. The position correcting apparatus for a working machine according to any one of claims 1 to 4, wherein said identification mark is subjected to a surface treatment optically different from that of individual constituting elements of said regular pattern.

6. The position correcting apparatus for a working machine according to claim 5, wherein said surface treatment is a low reflection treatment or an irregular reflection treatment.

7. The position correcting apparatus for a working machine according to claim 5, wherein said surface treatment is a mirror finish treatment.

8. The position correcting apparatus for a working machine according to claim 7, wherein said mirror-finished identification mark has a convex or concave spherical surface.

9. The position correcting apparatus for a working machine according to any one of claims 1 to 8, wherein said identification mark is embedded in said floor.

10. The position correcting apparatus for a working machine according to any one of claims 1 to 9, wherein said identification mark is fitted in a through hole constituting said regular pattern.

11. The position correcting apparatus for a working machine according to any one of claims 1 to 10, further comprising:

an illuminator provided near said image pickup means; and

a reflector for condensing light emitted from said illuminator in a field of view of said image pickup means on said floor.

12. The position correcting apparatus for a working machine according to any one of claims 1 to 11, wherein a plurality of image pickup means are provided with a predetermined position relationship;

and

said teaching data correction means corrects said teaching data of said working machine based on a result of comparison between said on-pause picked image and said reference picked image, both acquired by said plurality of image pickup means.

13. A stop-position deviation detecting device for obtaining a deviation between an on-pause picked image, acquired by picking up an image of a predetermined flat surface which has an arbitrary pattern and a predetermined identification mark formed thereon and on which a mobile body moves, with said mobile body stopped at a predetermined position, and a reference picked image, acquired by picking up an image of said flat surface, with said mobile body previously stopped at a predetermined reference stop position, by comparing said arbitrary patterns on said picked images with respect to said identification mark taken as a reference, thereby detecting an amount of deviation of said stop position of said mobile body based on said deviation, said apparatus comprising:

reference position data acquiring means for acquiring, from said reference picked image, position data of a plurality of pattern components constituting said arbitrary pattern and said identification mark on said reference picked image;

on-pause position data acquiring means for acquiring, from said on-pause picked image, position data of said plurality of pattern components and said identification mark on said on-pause picked image;

code assigning means for assigning common codes to said plurality of pattern components with said identification mark on each of said picked images taken as a reference;

associating means for associating said plurality of pattern components between said picked images in one-to-one correspondence based on said codes of said plurality of pattern components given by said code assigning means; and

deviation calculation means for acquiring a difference between said position data acquired by said reference position data acquiring means and said on-pause position data acquiring means for each set of said plurality of pattern components associated with one another by said associating means, and acquiring a deviation between said picked images based on said difference in said position data in each set.

14. The stop-position deviation detecting device according to claim 13, wherein a predetermined number of pieces of position data are selected from said position data of said pattern components, obtained by said reference position data acquiring means and said on-pause position data acquiring means, and said associating means performs an association process only on those pattern components corresponding to said selected position data.

15. The stop-position deviation detecting device according to claim 13, wherein said on-pause position data acquired means includes:

rough position data acquiring means for acquiring rough position data of said plurality of pattern components;

rough position data selection means for selecting a predetermined number of pieces of position data from said rough position data acquired by said rough position data acquiring means; and

detailed position data acquiring means for acquiring detailed position data of said pattern components corresponding to said rough position data selected by said rough position data selection means.

16. The stop-position deviation detecting device according to any one of claims 13 to 15, wherein said arbitrary pattern is formed by regular arrangement of said plurality of pattern components;

and

said code assigning means assigns codes based on regularity of the arrangement of said plurality of pattern components with said identification mark on each of said picked images taken as a reference.

17. The stop-position deviation detecting device according to any one of claims 13 to 15, wherein said code assigning means assigns codes to individual pattern components on said reference picked image based on vectors connecting said plurality of pattern components in order on said reference picked image with said identification mark as a starting point, and assigns codes common to those on said reference picked image, on said on-pause picked image with said identification mark as a starting point, according to said vectors.

18. The stop-position deviation detecting device according to any one of claims 13 to 17, wherein said reference position data acquiring means and said on-pause position data acquiring means perform a matching process on a predetermined template image and images of said plurality of pattern components and said identification mark to recognize said plurality of pattern components and said identification mark to thereby acquire position data of said picked images.

19. The stop-position deviation detecting device according to claim 18, wherein said plurality of pattern components of said arbitrary pattern are formed in the same circle;

and

an image of one of said circular components is used as said predetermined template image.

20. The stop-position deviation detecting device according to any one of claims 13 to 19, wherein said reference position data acquiring means and said on-pause position data acquiring means extract portions of binary images which have preset shape properties to recognize said plurality of pattern components and said identification mark to thereby acquire position data of said picked images, said binary images being obtained by binarizing individual picked images with a predetermined threshold value.

21. The stop-position deviation detecting device according to any one of claims 13 to 20, wherein said plurality of pattern components constituting said arbitrary pattern, one or two or more pattern components specifiable as said identification mark are taken as a reference in a process executed by said code assigning means.

22. The stop-position deviation detecting device according to any one of claims 13 to 21, wherein said predetermined flat surface is a floor made of a punching member or a grating member.

23. The stop-position deviation detecting device according to any one of claims 13 to 22, wherein said identification mark is subjected to a surface treatment optically different from that of said plurality of pattern components constituting said arbitrary pattern.

24. The stop-position deviation detecting device according to claim 23, wherein said surface treatment is a low reflection treatment or an irregular reflection treatment.

25. The stop-position deviation detecting device according to claim 23, wherein said surface treatment is a mirror finish treatment.

26. The stop-position deviation detecting device according to claim 25, wherein said mirror-finished identification mark has a convex or concave spherical surface.

27. The stop-position deviation detecting device according to any one of claims 13 to 26, wherein said identification mark is embedded in said floor.

28. The stop-position deviation detecting device according to any one of claims 13 to 27, wherein said identification mark is fitted in a through hole constituting said regular pattern.

29. The stop-position deviation detecting device according to any one of claims 13 to 28, further comprising:

an illuminator provided near said image pickup means; and

a reflector for condensing light emitted from said illuminator in a field of view of said image pickup means on said floor.

30. The stop-position deviation detecting device according to any one of claims 13 to 29, wherein a plurality of image pickup means are provided with a predetermined position relationship;

and

a deviation between said picked images is acquired based on said on-pause picked image and said reference picked image, both acquired by said plurality of image pickup means.

31. The stop-position deviation detecting device according to any one of claims 13 to 30, wherein an amount of a three-dimensional deviation of said stop position of said mobile body is obtained based on relationships among positions of said pattern components on said on-pause picked image and said reference picked image.