JPS6317735A - Takeout device - Google Patents

Abstract

PURPOSE:To make it possible to recognize a 3-dimensional position of each of stacked articles easily and to take out the articles one by one arranging an article position recognition device for instructing the position of the article to a takeout hand. CONSTITUTION:An article position recognition device 12 is provided with a projector 13 for projecting light from a specified direction to an aggregate body 2 of multiple articles 1 and a camera 14 keeping a certain length of base line relative to the projector 13. Projecting light from the projector 13 to the aggregate body 2 of the multiple articles 1, an image of light reflected from the article 1 of the aggregate body 2 is taken by the camera 14. An operation means 15, based on the image signal inputted from the camera 14, determines coordinates of the image and 3-dimensional position of the article 1 by operation based on triangulation using the coordinates, the preset base line length between the projector 13 and the camera 14, etc. Instructing the recognized position of the article 1 to a takeout hand 11, the article 1 is taken out by means of the takeout hand 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a picking device that picks out one (f) loaded articles.

(Prior art) In general, a private warehouse uses a pallet tie If (loading device) and a depalletizer (unloading device).
Loading and unloading takes place automatically. In this case, articles loaded by a palletizer can usually be easily unloaded by a depalletizer without a vision system. This is because when the palletizer loads, the computer stores the loading pattern and its order, and when the depalletizer unloads, the reverse operation can be performed based on the stored data.

However, even if the items are stacked in an orderly manner by the palletizer, there is a possibility that the items may be misaligned, or the items may be moved manually, or the items may be stacked in a similar pattern. In such a case, it is difficult to reliably unload the palletizer by simply performing a reverse operation based on the loading data of the palletizer. For this reason, unloading of articles one by one is often performed manually.

(Problems to be Solved by the Invention) As mentioned above, when the loading pattern is not constant or the loading condition is unstable due to shifting or being moved manually, it is necessary to In some cases, it may not be possible to unload each load automatically.

SUMMARY OF THE INVENTION An object of the present invention is to provide a picking device that allows easy recognition of the three-dimensional position of each loaded article and enables picking of articles one by one.

(Structure of the Invention) (Means for Solving the Problems) A picking device according to the present invention includes a picking hand 11
and an article position recognition device 12 for instructing the picking hand 11 to the position of the article 1. A camera 14 is provided with a constant base line length maintained with respect to the projector 13, and the reflected light from the articles 1 constituting the aggregate 2 is imaged by the camera 14. Further, a calculation means 15 inputs the image signal from this camera 14 and calculates the three-dimensional position of the article 1 constituting the aggregate 2 based on the coordinates of this image.
will be established.

(Function) In the present invention, light is projected from a projector 13 onto an aggregate 2 of a plurality of articles 1, and reflected light from the articles 1 of the aggregate 2 is imaged by a camera 14. The calculation means 15 is the camera 14
The eel mark is determined by inputting the video signal from
4, the three-dimensional position of the article 1 is determined by calculation based on the triangulation method. Then, the recognition position of the article 1 is instructed to the picking hand 11, and the article 1 is taken out by the picking hand 11.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes loaded articles, and a plurality of articles of each type are stacked in stacks to form an aggregate 2.

Reference numeral 10 denotes a traveling trolley, and on this traveling trolley 10 are provided a picking hand 11 that is movable in vertical and horizontal directions, and an article position recognition device 12 that indicates the position of the article 1 to be taken out to the picking hand 11.

This article position recognition device 12 will be explained with reference to FIG. In FIG. 2, a projector 13 projects horizontal slit light onto the side surfaces of the articles 1 constituting the aggregate 2.

A camera 14 is arranged with a constant base line length in the Z-axis direction with respect to the projector 13, and it captures the aggregate 2 on which light is projected by the projector 13 from diagonally above, and captures the aggregate 2. The reflected light is transferred to an image. The above projector 13 and camera 1
4 is configured to be movable in the Z-axis direction while maintaining the navigation baseline position by a movement elJI4 (not shown). Reference numeral 15 denotes a calculation means which inputs an image signal from the camera 14 and calculates the three-dimensional position of each article 1 based on the coordinates of the image (reflected light image) using a calculation method described later.

Next, the principle of operation of the article position recognition device @12 will be explained with reference to FIG. In the X-Y-Z rectangular coordinates as shown, if a grid is placed on the X-Y plane and the 0 point is looked down from the H point on the Z axis, even if the height from the 0 point to the H point is known. BaO
The distance 1ffiY between -0 is determined by the following equation.

Y = 1”tanθ1 ・・・・・・・・・・・・
(1) Similarly, the distances to corner points A and B on the Y axis can be found by the above equation by setting θ1 to the corresponding angle. Further, the (X, Y) coordinates of points D and E can be determined by the following equation by knowing the angle α on the XY plane in addition to the angle θ.

X = Htanθ・sinα・・・・・・・・・
・・・・・・・・・(2) y = Htanθ−cosα
(3) In this embodiment, each three-dimensional position of the loaded articles is determined and picked using the measurement principle described above.

In the above configuration, it is assumed that the camera 14 and the projector 13 are lowered along the Z-axis direction while maintaining a constant base line length. FIG. 4 shows an image captured by the camera 14 at this time. Note that the trapezoid in FIG. 4 represents the planar periphery of the aggregate 2, and the frame is the frame of the screen.

The projector 13 is lowered and is at a height P3, and the camera 1
Assume that 4 is in position Q3. At this time, the slit light from the projector 13 has not yet been projected onto the side surface of the assembly 2, but is projected onto the background as a line L3. In this case, the height Q
The image taken by the camera 14 at position 3 is shown in Figure 4 (2
), and the slit light image 1+13 is located outside the aggregate 2. Next, when the projector 13 is lowered to a height Ql, the slit beam is projected onto the side surface of the articles 1 (A, B, C) constituting the assembly 2 as a line L2. At this time, the image captured by the camera 14 at the height Ql is as shown in FIG. 4(C), and the slit beam is captured as an image L2. Furthermore, projector 1
3 is lowered to a height Ql, the slit light [is projected as a line L1 onto the side surface of the articles 1 (E, F, G) constituting the assembly 2. The image taken by the camera 14 at the height Ql at this time is as shown in FIG.

Next, the coordinates on the screen of the above-mentioned images @L1 and L2 (L3 can be ignored since it is outside the measurement range) are determined. For example, by setting the upper left corner of the screen in FIG. 4 as the origin, and taking X to the right and y to the bottom, the position of the pixel (coordinates
The distance in the x1Y direction from the projector 13 to the article 1 forming the images L1 and L2 is determined using . That is, the coordinate y determines the angle θ explained in FIG. 3, and the coordinate X determines the angle α. Since H is determined as h, the coordinates X and Y of the XY plane in Figure 4 are (1
) (2) Calculated from equation (3).

In this way, the position of each article 1 in the X and Y directions is determined, and the position in the Z direction is determined from the height of the projector 13, so the three-dimensional position of each article 1 is recognized and based on this position data. By controlling the controller of the picking hand 11 and moving the picking hand 11 in accordance with the position and state of the article 1, each article 1 can be reliably picked.

The embodiment shown in FIG. 5 uses a projector 13 that projects slit light in two stages, upper and lower.

In this case, the upper slit light is projected onto the background, and the lower slit light is projected onto the side of the article 1 at the top of the assembly 2, thereby stopping the descent of the projector 13 and camera 14. If this is done, the position of the article 1 at the top of the assembly 2 can be recognized at all times, which is optimal as position data for unloading work. In addition, the projector 13
Even when controlling the descending stop of the camera 14, the lower slit light is always stopped when it descends a certain distance from the top surface of the article 1, so compared to the case of the instep slit light where the descending stop position is not constant, Operation is stable without being affected by descending speed, etc. Furthermore, since two levels of slit light, upper and lower, are used, the angle of the article relative to the front can be easily determined, allowing for more accurate position recognition.

FIG. 6 shows an example of recognition when the loading state of the articles 1 in the assembly 2 is normal and when a part of the articles 1 is misaligned.

In FIG. 2, the articles 1 are loaded correctly, and the image created by the slit light on the screen also shows a normal state according to the outer edges of the articles 1. ) is a case in which one item in the assembly 2 (the item in the middle row on the right) is shifted outward in parallel, and the image created by the slit light on the screen also represents this shift. This diagram also shows a case where one article (the one in the middle row on the right) is shifted in the rotational direction, and the image created by the slit light on the screen also represents this shift in the rotational direction.

In this way, even if the article 1 is not in a normal loading state, it is possible to recognize the position of the article 1, including its misalignment, from the image obtained by the slit light beam, and it is possible to perform picking that takes into account such misalignment. .

In the embodiment shown in FIG. 7, a plurality of code masks 1f3 (A, B, C) are used as the projector 13 to project the code pattern, and the code pattern projected onto the article 1 is transferred to the camera 14.
The image is created by Here each code mask 1
6 (Δ, B, C), the black portions transmit light, and the white portions transmit light.

In the above configuration, first, light is projected onto the article 1 using the code mask 16 of A. Here, the bright portion through which light is transmitted is designated as “1”, and the bright portion where light is blocked is designated as “O”.

The calculation means 15 stores the above-mentioned "1" or OII for each pixel constituting the screen based on the image signal from the camera 14.Next, the code mask 16 of B is used to similarly project light, and the current Based on the image signal from the camera 14, "1pa" or "O" is stored for each pixel. Furthermore, light is projected using the code mask 16 of C, and each image Sf
Store “1 Pa or O゛” in e. That is, projector 1
3 uses three code masks 16 (A, B, C) to create a 3-bit binary code (area 0
projects code 000, region tii projects code 001, region 2 projects code 011, etc.).

Further, since the calculation means 15 stores the code pattern projected onto the article 1 by image transmission from the camera 14 for each pixel, it can be determined which pixel captures which code.

In this way, the direction of projection (angle φ) is determined by the spatial code projected from the projector 13, and the line of sight direction of the camera (angles θ, δ ) is obtained.

Therefore, the coordinates X, Y, and Z of the article 1 can be determined by the following equation using the previously determined base line [d.

Z=d/(tanθ−tanφ) X=Ztanδ Y=Ztanθ In addition, the code is "-Domask 16 (A.

In order to prevent recognition errors at the boundaries of the eight areas due to positional deviations in B and C), a known Gray code (inverted 2 inverted code) is used.

A position recognition device using such a gray code is suitable for recognizing the position of bags containing cement, grain, etc. That is, since such a back is not a regular shape, it is difficult to recognize its position using the slit light described above, but a position recognition device using a gray code does not have a regular shape and can sufficiently recognize its location. For example, when unloading such a bag, a vacuum hand is attached to the top surface of the bag to lift it up, and it is necessary to recognize the top surface of the loaded bag. In this case, position recognition using a slit light is difficult, but position recognition using a gray code is fully possible.

Furthermore, when using a vacuum hand, it is necessary to check the smoothness of the top surface of the bag, but with this recognition device using Gray code, it is possible to easily detect the smoothness of the top surface of the bag based on the distortion of the Gray code. .

〔Effect of the invention〕

According to the present invention, since the positions and conditions of a plurality of loaded articles can be reliably recognized, the picking of these articles can be ensured, and the unloading operation of each article 111iil can be easily automated (up to 4 steps can be carried out). can.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of a picking device according to the present invention, FIG. 2 is an explanatory diagram of the article rental recognition device shown in FIG. 1,
Fig. 3 is an explanatory diagram of the measurement principle in Fig. 2, Fig. 4 is an explanatory diagram of the image in Fig. 2, Fig. 5 is an explanatory diagram showing an embodiment with two stages of slit light, and Fig. 6 is an explanatory diagram of the article. An explanatory diagram showing a comparison of recognition examples when the loading state is normal and when the loading state is normal;
FIG. 7 is an explanatory diagram showing an embodiment using a Gray code. 1... Article, 2... Aggregate, 11... Picking hand, 12... Article position recognition device, 13... Projector, 14...
- Camera, 15... Arithmetic means, 16... Gray code mask. +X

Claims (3)

[Claims] (1) Equipped with a picking hand and an article position recognition device that indicates the position of an article to the picking hand, and this article position recognition device is a projection device that projects light from a predetermined direction onto an aggregate of a plurality of articles. a camera that is installed at a constant baseline length with respect to the projector and captures the reflected light from the objects that make up the aggregate; an image signal from the camera is inputted, and the image signal is input based on the coordinates of the image. A picking device comprising: arithmetic means for determining three-dimensional positions of articles constituting an aggregate; (2) A patent claim characterized in that the projector is a device that projects horizontal slit light onto the side surfaces of the articles constituting the assembly, and the camera is arranged so as to overlook the assembly from diagonally above. The picking device according to item 1. (3) As a projector, a device that projects a Gray code pattern based on a plurality of Gray code masks onto the items constituting the aggregate is used, and as a calculation means, the content of the Gray code that makes up the image and its coordinates are used to The picking device according to claim 1, characterized in that a device for determining the original position is used.