JPS5943479A - Visual recognizing device - Google Patents

Abstract

PURPOSE:To discriminate the position of an object in addition to the shape of the object, by allowing a coherent parallel light to pass through an freely attachable and detachable mesh shaped two-dimensional grating whose pitch is changed linearly in vertical and horizontal directions in accordance with positions. CONSTITUTION:The light from an object 30 to be recognized is reflected by a means 7 and is focused onto a filter 9 by a lens 8 and passes through an optical valve 29 to form a luminous flux 34, and this luminous flux 34 passes through an analyzer 24 and a light valve 25 and is focused onto a detector 28 through a two-dimensional grating plate 27 and a Fourier conversion lens 26. The two-dimensional grating 27 has the pitch changed linearly in vertical and horizontal directions in accordance with positions and is freely attached and detached; and in the detector 28, photoelectric converting elements are arranged into the shape of L. The laser light from a light source 10 is polarized linearly by a means 12 and is reflected by a mirror 13 to become a parallel light, and this parallel light passes through the light valve 29 and the analyzer 24 and has the amplitude modulated by the image of the object 30 on the optical valve 29 and passes through the filter 25 and the grating plate 27 and is subjected to Fourier conversion by the lens 26 and is focused onto the detector 28. Thus, the position of the object 30 is discriminated, and the grating plate 27 is removed to discriminate the attitude of the object 30.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an object A, 1, which is an object handled by an assembly robot or the like.
1＼脣) (4 items) This relates to a visual recognition device for detecting the f device, shape, and posture.

Configuration of conventional example and its problems Conventional visual recognition devices for robots perform image processing using a computer on two-dimensional image information of the recognition target photographed by a television camera to determine the position, shape, and color of the recognition target. Detecting force, etc. , in such a method, 1
It is necessary to scan the zumbling line over the entire image information per frame, perform pattern matching with a standard pattern, etc., and the real-time processing that is essential for robot vision is necessary. This has the disadvantage of making it difficult to realize. As a means of determining the shape and orientation of a recognition target, devices that apply optical two-dimensional Fourier transform have traditionally been used.

Figures 1 (ca) and (b) and Figures 2 (a) and (b) show specific configuration examples of conventional visual recognition devices that apply optical two-dimensional Fourier transform. In FIG. 1(a), 1 is a laser generator, 2 is a collimator, ] 4 is a Fourier transform lens, 4 is a recognition target, and 5 is a detector.
, the detector 6 has a light intensity detection section in which photoelectric elements are arranged in a strip and a ring shape, as shown in FIG. 1(b), for example. Convert 7.S3 (4-) to form an image according to the shape of the object 4 to be recognized 1:
, i'(-parallel no--+f-1f, two-dimensional no-respe2 of the pattern) Nine distributions are detected. In Figure 2<a), 6 ((1, jicl, object 7 is a reflecting mirror, 8 is an image forming lens, 9 is a He
Ne is an optical filter that passes only i (t, z) with a shorter wavelength than the laser source, 1o is a HeNe1/- Lee generator, 12 is a polarizing plate, 13 is a half mirror, 114 is a light valve, 15 is a polarizing plate 12 16 is an optical filter, 17 is a Fourier transform lens, 18 is a light intensity 'J) 4 detector, and 19 is an optical axis of the optical system. Light valve 14 (, 12, example, (1'') second
As shown in the figure, a photoconductive member layer 20 and a crystal part layer 21 having a -order electro-optic effect are placed on a transparent plate 22.
, 23, and the polarizing plate 12 polarizes the light into linearly polarized light. ．． Am'T = -Sir light passes between the transparent electrode plates 22 and 23 Q□C'iii, the light valve 14 and the analyzer plate 15 to which pressure is applied, lJ! After one lapse of time, the amplitude distribution of the image of the recognition object 6 formed on the photoconductive surface of the light valve 14 by the imaging lens 8 is linearly modulated in accordance with the light intensity distribution.

The optical filter 16 blocks light other than the parallel laser beam, and a Fourier spectrum corresponding to the amplitude distribution of the parallel laser beam is imaged on the focal plane of the Fourier transform lens 1''. In the conventional configuration shown in Figure 2 (d) and Figure 2 (Ca), regardless of the positions of the recognition objects 4 and 6 placed within the visual field, the image is formed with the same aspect. Therefore, it was impossible to detect the position of the object.Therefore, this method is only used as a means of automating visual inspection to determine the shape etc. of the part. However, it has not been applied as a visual device for robots.

Purpose of the Invention In view of the above-mentioned shortcomings of the conventional example, the present invention is based on a power method that processes two-dimensional image information in parallel in an analog manner by utilizing the coherence of coherent light such as a shear. The present invention provides a visual recognition device that can quickly determine the position, shape, and orientation of assembly parts, which are objects handled by assembly robots, etc., in addition to the function of detecting .

Composition of the Invention The present invention IJ, l1.1 An optical system for forming an optical image of an object to be recognized, a laser generator for obtaining a parallel beam of light, and an optical system for an object to be recognized. Brightness and darkness of the image ↑J
A converter that converts the amplitude distribution of Xi coherent parallel rays, a reticular two-dimensional grating that is juxtaposed with the converter, and whose pitch changes linearly depending on the position in both the vertical and horizontal directions, and which is easy to attach and detach. It consists of a Fourier transform lens that images the Norier spectrum of coherent parallel light that has passed through a two-dimensional grating, and a detection section that detects the light intensity distribution of this Fourier spectrum. Image information of the recognition target is transformed by complete conversion! 5. Description of Embodiments Below, embodiments of the present invention will be described with reference to the drawings. I will explain. FIG. 3 shows the configuration of a visual recognition device in an embodiment of the present invention. In the embodiment shown in FIG.
In addition to the configuration of the conventional example shown in Figure (a), analysis) l) i2
4 and the optical filter 250 or between the optical filter 25 and the Fourier transform lens 26, as shown in FIGS.
) are arranged in parallel, and the detector 28
The device has a light intensity distribution detection section in which photoelectric conversion photons are arranged in a straight L-shape with seven columns as shown in FIG.

Regarding the visual recognition device configured as above, the following □
Let's explain its operation. Similar to the conventional example shown in FIGS. 2(a,) and 2(b'), the linearly polarized parallel HeNe laser beam is transmitted through the light valve 29. By passing through the L analyzer plate 24, the light is amplitude-modulated in proportion to the light intensity distribution of the recognition object 3o imaged at the position of the light valve 29, and further passes through an optical filter 25 and a two-dimensional grating plate 27, The Fourier transform lens 26 forms an image of the Fourier spectrum on the light intensity sensing portion of the detector 28 .

As shown in FIG. 4 Ca), the two-dimensional grid plate 27 has a mesh grid 32 formed on one side of a transparent glass substrate 310 by chromium vapor deposition or photographic technology3.The pitch of the mesh grid 32 is , l! shown in FIG. 4(b). Sea urchin, (
Changes linearly depending on the position in both the 4 directions and the lateral direction.
It is something to do. That is, in Fig. 4 (4 in bl), the pitch (ax, by) of the grating at position (X, y) is ax-: a0+Δa@x, b-, =b, +-Δb-y
Let it be expressed as Here, (ao, b.) is the pitch of the grating at the origin, and (Δa, Δb) is the proportionality constant. Although it depends on the size of the light intensity detection section, it is approximately in the range of several tens of microns to several l''f1 microns.

In FIG. 3, the recognition target 30 is
When the target object 30 enters the field of view of the optical system 33, an optical image of the object 30 to be recognized is formed at the position of the light valve 29, and a parallel laser beam 34 with a relatively large amplitude is emitted from the position of the optical image. 1
-1 This parallel laser beam 34i; It passes through a portion A of the mesh lattice 32 shown in FIG. 4(a). If the position of the part A of the mesh L1-like lattice 32 is the coordinates (x, y) shown in FIG.
The onset of the courier spectrum shown in Figure 5 (x/ , y
/ ) has a one-to-one correspondence with (x, y),
For example, as shown in FIG. 6, the position of the recognition target object 30 is determined by detecting it with photoelectric conversion elements arranged in an L-shape.

- Still removing the two-dimensional grating plate 26 and enlarging the recognition object 30 within the field of view of the optical system 33.
Recognition target 3 in a plane perpendicular to the optical axis of the optical system 33
o's posture can be determined.

Figure 7 cal, Cb'l, Figure 8 (a), Cb
) shows an example of posture determination. If the object to be recognized is a screw with a cross-shaped groove on its head, as shown in Fig. 7(a), its Fourier spectrum will also be cross-shaped as shown in Fig. th). Based on the conventional example shown in Figure 1 (b), the rotation angle θQ of the screw is determined by a wedge-shaped light intensity detection element.
can be detected.

When the object to be recognized is a hexagon socket head bolt 1.1 as shown in Figure 8(a), its Fourier spectrum will be as shown in Figure 8(b), rotation angle α0
Note that in the above embodiment, the position detection and orientation determination of the recognition target object 3o are switched by attaching and detaching the two-dimensional grating plate 26 and enlarging the optical image. Alternatively, the optical path may be divided by a mirror or the like and switched by a shutter or the like.

Due to the effects of 2 and 3, the present invention converts the intensity of the optical image of the object to be recognized into the amplitude distribution of the 7-IJ laser beam, and converts it by the 7-IJ 2-conversion lens. A device that images a Fourier spectrum corresponding to the amplitude distribution is equipped with a pinot
Change J linearly according to the horizontal and vertical positions/3
- By providing a mesh [one-dimensional two-dimensional grid] that can be easily attached and detached,
Since it is possible to detect not only the shape and posture of a recognition target but also knee-dimensional position information at high speed, it can be applied as a high-speed responsive visual recognition device for robots. -1

[Brief explanation of the drawing]

Figure 1(c) is a schematic configuration diagram of a conventional optical two-dimensional Nolier transform analysis device, Figure 1(b) is an explanatory diagram of the light intensity distribution detection unit of the detection unit pot in Figure 1(h), Figure 2 (a)
2 is a schematic configuration diagram of a visual recognition device equipped with a function of converting the light intensity distribution of a conventional optical image into an amplitude distribution of a coherent stomach. FIG. FIG. 3 is a schematic configuration diagram showing an embodiment of the present invention, FIGS. 4(a) and (b) are enlarged explanatory diagrams of the two-dimensional lattice plate in FIG. 3, and FIG. 5 is a mesh diagram. FIG. 6 is a diagram showing an example of the Fourier spectrum of a parallel laser beam that has passed through a part of the shaped grating. FIG. b), FIGS. 8(a) and 8(b) are diagrams showing an embodiment of the attitude determination of a recognition target object according to the present invention. 24-・Analyzer, 25... Optical filter, 26
...Fourier transform lens, 2..... Two-dimensional grating plate, 28... Detector, 29...
Light valve, 30... Recognition target, 31...
Glass substrate, 32...Mesh lattice. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure B) Figure 3 Figure 4 (α) (Vagina Figure 5 Figure 6 Figure 8rA -469-

Claims (1)

[Claims] 10. An optical system for forming an optical image of the object, a device for obtaining coherent parallel rays, and an apparatus for adjusting the brightness distribution of the optical image by the amplitude of the coherent parallel rays.
A converter that performs K conversion, the converter, 1(・
a removable mesh-like two-dimensional lattice whose pitch changes linearly in two directions perpendicular to each other;
A visual recognition device comprising a Fourier transform lens that images the No. 1 Noe spectrum of tm on its focal plane, and a detection section that detects the light intensity distribution of the tooling vector.