JP2001225952A - Picking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a clearance between an article and a lower article even if an article to be picked projects forward. SOLUTION: The clearance between articles is detected from a discontinuous part of reflected light by providing a CCD camera 40 and line lasers 41, 42 on the bottom of a belt conveyer 16 of the tip of the picking device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a picking apparatus for picking up articles from a truck bed, an automatic warehouse shelf, a clean room station, and the like, and more particularly to a method for determining a boundary of an article to be picked.

[0002]

2. Description of the Related Art The inventors have developed an apparatus for picking up articles from a truck bed or the like. This picking device is provided with a picking head such as a belt conveyor or a fork at the end, picks up an image of an article with a CCD camera or the like, recognizes a boundary of the article, and determines a position for picking with the head.

FIG. 9 shows an image recognition system in this picking device. Reference numeral 40 denotes a CCD camera, which picks up an image with light from a lamp 90 and detects a boundary between the articles 60. By the way, in the image recognition system of FIG. 9, when the upper article is forwardly convex with respect to the lower article, the step 70 is not visible, and the upper and lower articles appear to be continuous, and the boundary is recognized. I want to.
For example, in the case of FIG. 9, the reflected light 92 from the lower part of the step 70 and the reflected light 91 from the upper part are continuous in the image of the CCD camera 40, and it is difficult to detect the gap between them. When it is difficult to recognize the boundaries of the articles depends on the arrangement of the image recognition system. In any case, if the front of the article to be picked is in a convex or concave relationship with the surroundings. , It becomes difficult to recognize the boundaries.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to make it possible to recognize the boundary of an article even when the front surface of the article is convex or concave with respect to the surroundings. Claims 1-3). An additional problem with the invention of claim 2 is that
An object of the present invention is to make it possible to detect that an article is placed in an inclined state and to detect the inclination. An additional object of the third aspect of the present invention is to make it possible to reliably pick an article placed at an angle.

[0005]

The picking apparatus of the present invention is an apparatus which picks up an object to be picked up by a camera and picks up the image while recognizing the image of the camera.
An irradiation unit for irradiating light in a line shape to a boundary portion of the article, and a boundary recognition unit for obtaining a discontinuous portion in reflected light of the irradiation light from the camera image and obtaining a boundary point of the article are provided. (Claim 1).

Here, the discontinuous portion means a position where the brightness of the reflected light changes rapidly or a position where the position of the reflected light changes rapidly. Further, as shown in the embodiment, the type of the picking device is not limited to a picking device in which a picking head is mounted on the tip of a main body of a self-propelled picking device, and is used for picking articles. A transfer device of a crane, an automatic guided vehicle, a tracked truck, a transfer device in a fixed station, or the like may be used.

The irradiating means may be a means for extracting light from a light source such as a discharge lamp through a slit. However, it is preferable that the irradiating means is constituted by a laser, and irradiates the laser light in a line shape to at least two places on the boundary of the article. To do it. In this case, the light from one laser may be divided into two by an optical system such as a half mirror and applied to two lines, or the light from two lasers may be used. The laser may output a normal beam-shaped laser light. However, if a line laser is used, an optical system for changing the direction of the laser light and performing scanning in a line becomes unnecessary. Then, the boundary recognizing means obtains a boundary portion of the article so as to connect at least two boundary points of the article obtained by each irradiation light (claim 2).

Particularly preferably, a head for picking an article is provided at the tip of the picking device, and means for raising and lowering the head and means for rotating the head about an axis in the picking direction are provided. Then, the head is raised and lowered and rotated about an axis in accordance with the obtained boundary portion (claim 3).

[0009]

According to the present invention, the boundary portion of the article is irradiated with linear light, and the boundary point is determined from the discontinuous portion of the reflected light. The reflection pattern for linear light is different at the boundary between the front surface of the article and the surroundings. Generally, the boundary of the article appears as a dark part in the reflection image of the linear light, which is an example of a discontinuous part of the reflected light. It is. Next, if there is a shift in the front-rear direction between the front surface of the article and the periphery, that is, if the front surface of the article is convex forward or concave with respect to the periphery, the line of reflected light is broken, and this break is not caused. The boundary of the article can be recognized as a continuous part. Therefore, according to the present invention, even when the front surface of the article has a convex or concave relationship with the surroundings, the boundary of the article can be easily recognized (claim 1).

According to the second aspect of the present invention, two boundary points of the article are irradiated with linear light, so that two boundary points are obtained, and a line connecting these two points becomes a boundary of the article. For this reason, the boundary line of the article is determined, and the presence / absence and degree of inclination of the article are determined from the boundary line (claim 2). If articles are stacked irregularly and there is a wide gap between the articles, the center of the gap may be used as the boundary line, or the upper end of the gap may be used as the boundary line. Whether to do so may be determined according to the type of picking head and the like.

According to the third aspect of the present invention, the head at the tip of the picking device is configured to be vertically movable and rotatable about an axis along the picking direction, and the head is raised and lowered in accordance with the height of the determined boundary. The head is rotated according to the inclination of the boundary. For this reason, picking can be reliably performed even with an inclined article (claim 3).

[0012]

1 to 8 show an embodiment of a picking device . 1 and 2 show the structure of the picking device 2. Reference numeral 3 denotes a vehicle body, 4a and 4b denote left and right frames, 6a to 6d denote a total of four front, rear, left and right running wheels, and 8a and 8b denote left and right running wheels. The drive unit includes a traveling motor (not shown), a speed reducer, and a brake. The front and rear traveling wheels 6a / 6b, 6c / 6d are connected to the left and right chains 9a, 9
Power is transmitted by transmission means such as b. The picking device 2 includes traveling wheels 6a to 6d and traveling driving units 8a,
8b allows forward and backward movement and turning in a horizontal plane and lateral movement in the left and right directions. Crawler travel may be used instead of wheel travel, and front and rear wheels 6a / 6b,
Instead of connecting 6c / 6d, four-wheel independent drive may be used, or only the front or rear wheels may be drive wheels, and the other may be driven wheels.

Reference numeral 10 denotes an upper frame, which is composed of left and right frames 4.
a and 4b are connected. By using the frames 4a and 4b and the upper frame 10, the base side conveyor 12 and the like consisting of a belt conveyor, a roller conveyor and the like are raised and lowered. is there. Reference numeral 16 denotes a belt conveyor on the tip side, which is an example of a head for picking and loading.
A conveyor 8 is located between the belt conveyor 16 and the roller conveyor 14. Reference numeral 20 denotes a conveyor frame below the conveyor 12, reference numeral 22 denotes a guide connected to the conveyor frame 20, reference numeral 24 denotes a guide arranged at the bottom of the conveyor 12, and the like. 28 is a rotating shaft, and the conveyors 12, 14, 16, and 18 are rotating shafts 28.
Can be rotated around a horizontal plane by the joint 26.

A pantograph 15 expands and contracts the roller conveyor 14, and a rotary drive 32 is provided for the conveyors 16 and 18.
Is rotated in the roll angle direction around the axial direction of the conveyor 14. This rotation angle is shown in FIG. 2 as θ, and the rotation axis is an axis along the picking direction. When articles are stacked in an inclined state, the conveyor 16 is tilted for picking. Reference numeral 34 denotes a scoop shaft, which is a belt conveyor 16 at the tip.
Is rotated in the dive / squat direction about the scoop shaft 34. The rotation angle is shown in FIG. 2 as φ, which is effective when picking or loading articles at a position lower than the conveyors 12 and 14. The arm 36 in FIG. 2 has a distal end fixed to the conveyor frame 20 and a proximal end moving forward and backward in the frames 4a and 4b.
By raising and lowering 0, the conveyor 16 is raised and lowered. It should be noted that another conveyor or the like shown by a chain line in FIGS. 1 and 2 is connected to the base conveyor 12 so that picked or loaded articles are carried in and out.

In the picking device 2 according to the embodiment, the conveyors 12 to 18 are supported by the frames 4a, 4b, 10, 20 and the like, and the vehicle body 3 moves forward and backward, turns, moves sideways, and the arm 3 moves.
The posture is controlled toward the work position by the lifting and lowering movement using the rotation 6 and the rotation about the rotation shaft 28. Further, the rotation of the conveyor 16 by the rotation drive unit 32 and the scoop shaft 3
The rotation of the conveyor 4 controls the direction of the conveyor 16. Further, the belt conveyor 16 is advanced by using the pantograph 15 at the time of picking or loading, and is brought into contact with the article to be picked and picked up or unloaded. The picking device 2 can be used for picking an article from a truck, a shelf, a pallet, or the like, and for regularly loading the article onto these items.

The control system of the picking device 2 will be described.
An upper camera 38 is provided on the top surface of the upper frame 10 and captures an image of a mountain of the article 60 to be picked as a whole. In addition, for example, near the head at the tip of the picking device, at the lower portion of the belt conveyor 16 or the like, a CCD camera 4
0, and locally image the vicinity of the lower boundary of the article to be picked using reflected light with respect to linear irradiation light from the pair of line lasers 41 and 42. As a result, an overall image and a local image of the work target portion are obtained, and a height position and a direction necessary for the work of the conveyor 16 are obtained by image recognition described later.

Reference numeral 44 denotes a base controller provided on the frame 4a, for example, which communicates with a host controller 46, receives a work command, and reports a work result. Base controller 4
4 is provided with an image recognition device and the like, processes images from the cameras 38 and 40, and particularly detects a discontinuous portion in the reflected light of the irradiated linear laser light in the image from the camera 40. Thus, for example, the lower boundary of the article, that is, the gap 62 between the articles
Is detected.

The discontinuous portion to be detected is a discontinuous point of light and dark in the image of the reflected light (dark portion of the line of the reflected light) or a discontinuity of the position of the line of the reflected light. And the base controller 44
Generates a straight line connecting two discontinuous points (boundary points) obtained using reflected light of irradiation light from the two line lasers 41 and 42, and sets this straight line as a lower boundary of the article.
When the discontinuous portion is wide vertically, the upper end in the discontinuous portion is defined as a boundary point. This is, for example, the upper point of the two points where the image changes from dark to light in the discontinuous portion, or the position of the upper article in the gap of the article where the reflected light is reconnected. .

As shown in FIG.
The pick-up device 2 can be controlled by connecting the hand operation unit 48 by a cable, infrared communication, or the like, separating the hand operation unit 48 from the vehicle body 3. A touch panel 50 is provided on the hand operation unit 48. For example, an image of the line laser imaged by the CCD camera 40 is superimposed on an image captured by the upper camera 38 and displayed.
By touching, it is possible to specify a work range such as a start position and an end position of the work, the number of repetitions of the work, or individual articles to be picked.

A keyboard 52 is provided on the hand operation unit 48 so that various operations and values of variables can be input. For example, 52a is a right movement key, 52b is a left movement key, and 52b is a left movement key.
When the user presses 2a and 2b, the vehicle body 3 moves rightward or leftward by a predetermined distance. The width of one horizontal movement can be changed, for example, by inputting it as a variable from the keyboard 52 or the like, and it is convenient to set the width to the width of one article to be worked or a value of about 1/2 to 1/5 thereof. Or keys 52a, 52
The length of time that b is pressed, or keys 52a, 52
It is convenient if the lateral movement distance can be input by the pressure of pressing b or the like.

In the embodiment, the hand operation section 48 is provided for manual operation. However, the position thereof is arbitrary, and a voice input section (not shown) is provided in place of the operation section 48 to control the picking device 2 by voice. You may do it.

The object 60 to be picked or loaded is a cardboard or the like, and is loaded on a truck bed, for example.
At the time of picking, when the belt conveyor 16 is brought into contact with the article to be picked and the conveyor 16 is moved as shown in FIG. Conveyed. The conveyed article is sent to the conveyor 12 via the conveyors 18 and 14, and is conveyed to the right side in FIGS. When the conveyor 16 is moved in the reverse direction at the time of loading, the articles are unloaded at the tip of the conveyor 16.

Before picking the next article, the pantograph 15 is contracted, the contact between the conveyor 16 and the article 60 is cut off, and the arm 36 is moved up and down to a position suitable for picking the next article. Then, the conveyor 16 is moved.

In order to recognize the article 60 with the picking device, it is necessary to detect the position of the border, especially the lower border of the article 60. The boundary recognition of the article 60 will be described with reference to FIGS. As shown in FIG. 3, the irradiation lines 65 and 66 of the pair of line lasers 41 and 42 are C
It is preferable to arrange the CD camera 40 obliquely in a plan view from the center line 64C of the visual field 64 of the CD camera 40. This way,
When there is a step before and after the boundary between the articles 60 in the pile of articles 60, the boundary between the articles can be more easily recognized. Article 6
Since the lower boundary point of 0 is obtained for each irradiation line 65 and 66 of the line laser, in the case of the embodiment, two boundary points are obtained,
If a straight line connecting these is obtained, the position and inclination of the lower boundary of the article 60 are determined.

FIG. 4 shows the irradiation line 6 from the line laser 42.
6 is shown along the vertical direction, in the gap (boundary) 62 between the articles 60, 60, the reflected light is widely diffused in directions other than the CCD camera 40, so that the CCD camera 40 has the gap 62.
Appear dark, from which the boundaries can be detected.

FIG. 5 shows an upper article 60u and a lower article 6
0d, and when the upper article 60u is stacked on the lower article 60d without tilting, dark areas are generated at the boundaries in the radiation images 67 and 68 viewed from the CCD camera 40,
This is defined as a discontinuous point (boundary point) between the images 67 and 68 of the irradiation line. On the other hand, as shown by a chain line in FIG.
Is stacked at an angle, the image of the irradiation line is line 67m,
It changes like 68m and the width of the dark part increases. Also in this case 2
Since two boundary points are generated, an upper point at which the color changes from dark to bright is obtained, and these points are connected to each other, whereby the lower end position of the upper article 60u and its inclination can be determined.

FIG. 6 shows images 67 and 68 of the irradiation light from the line lasers 41 and 42 when there is a front and rear step between the upper and lower articles 60u and 60d. As shown on the left side of FIG. 6, it is assumed that there is a step 70 between the upper and lower articles 60u and 60d, and the upper article 60u is convex forward. The irradiation lines 65 and 66 of the pair of line lasers 41 and 42 are
It is arranged obliquely with respect to the center line 64C of the visual field of the D camera 40. Then, the position where the laser light is reflected differs between the upper article 60u and the lower article 60d as shown by the solid line and the chain line in FIG. For this reason, as shown on the right side of FIG.
Appears, and the boundaries between the articles 60u and 60d can be clearly recognized. Although the gap 72 occurs even when the irradiation lines 65 and 66 are parallel to the center line 64C of the visual field, the gap is smaller than that in the case of FIG.

In the embodiment, a pair of line lasers 41, 42
However, a single line laser may be used, or a laser that outputs a normal beam-shaped laser beam (spot-shaped laser beam) may be used. Such examples are shown in FIGS. However, in these examples, the laser beam is split,
A movable optical system for scanning with a beam of laser light is required, which is not preferable. FIG. 7 shows a line laser 42.
Is split by a half mirror 74, the reflected light from the half mirror 74 is reflected by a mirror 76, and a pair of linear laser lights is generated.

In the modification shown in FIG. 8, light from a normal beam laser 80 is split into two beams by using a half mirror 74 and a mirror 76, and the articles 60, The boundary between the 60s is scanned, for example, in the vertical direction.

In the embodiment, a pair of linear laser beams is used. However, the laser beam may be a single line or a slit beam extracted from a discharge lamp or the like. Further, the lasers 41, 42, and 80 may be provided at locations other than the head at the tip of the picking device.

In the embodiment, picking is performed by using friction between the belt conveyor 16 and the article. However, a fork or the like is used instead of the belt conveyor 16 at the tip, and a fork or the like is inserted into a gap between the articles. May be picked. Further, the picking device may be mounted on a stacker crane, an automatic guided vehicle, a tracked truck, or the like, and may be transported, or may be arranged at a fixed station.

[Brief description of the drawings]

FIG. 1 is a plan view of a picking device according to an embodiment.

FIG. 2 is a side view of the picking device according to the embodiment.

FIG. 3 is a main part plan view showing an arrangement of a boundary recognition unit in the picking device of the embodiment.

FIG. 4 is a side view of a main part showing an arrangement of a boundary recognition unit in the picking device of the embodiment.

FIG. 5 is a front view showing an image of irradiation light of a line laser in the picking device of the embodiment.

FIG. 6 is a diagram showing characteristics of a reflection image of a boundary portion in the embodiment when articles are stacked convexly in front.

FIG. 7 is a diagram showing boundary recognition in an embodiment in which one line laser beam is divided by a half mirror.

FIG. 8 divides one laser beam with a half mirror,
Diagram showing boundary recognition operated by a movable lens

FIG. 9 is a diagram showing a pattern of reflected light in a conventional example when articles are stacked convexly in front.

[Explanation of symbols]

 2 Picking device 3 Body 4a, 4b Frame 6a-6d Running wheel 8a, 8b Running drive 9a, 9b Chain 10 Upper frame 12 Conveyor 14 Roller conveyor 15 Pantograph 16 Belt conveyor 18 Roller conveyor 20 Conveyor frame 22, 24 Guide 26 Joint 28 Rotation axis 32 Rotation drive unit 34 Scoop axis 36 Arm 38 Upper camera 40 CCD camera 41, 42 Line laser 44 Base controller 46 Upper controller 48 Hand operation unit 50 Touch panel 52 Keyboard 52a Right movement key 52b Left movement key 60 Article 62 Gap 64 Field of view 65, 66 Irradiation line 67, 68 Image of irradiation line 70 Step 72 Gap 74 Half mirror 76 Mirror 80 Laser 82 Movable lens

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 2F065 AA15 BB17 DD03 FF04 GG04 GG16 KK02 MM22 MM23 MM24 MM25 MM28 PP04 PP05 PP15 PP22 3F022 JJ07 JJ15 KK01 LL05 LL07 LL11 MM08 3F030 AA04 AB04 BA03 BA04 BB01

Claims (3)

[Claims] An apparatus for picking up an article to be picked up by a camera and picking up the image while recognizing the image of the camera, wherein a irradiating means for irradiating light to the boundary of the article in a line shape. And a boundary recognizing means for obtaining a discontinuous portion in the reflected light of the irradiation light from the camera image to obtain a boundary point of the article. 2. The method according to claim 1, wherein the irradiating means is configured to irradiate at least two points on the boundary of the article with laser light in a line shape, respectively, and the boundary recognizing means is configured to detect at least two points determined by the respective irradiating lights. 2. The method according to claim 1, wherein a boundary portion of the article is obtained by connecting the boundary points of the articles.
Picking equipment. 3. A means for picking up an article at a tip of the picking device, means for moving the head up and down, and means for rotating the head about an axis along the picking direction. 3. The apparatus according to claim 2, wherein the head is moved up and down and rotated around the axis in accordance with the determined boundary portion.
Picking equipment.