JP2010006510A - Picking device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To take out an article at the uppermost stage without totally taking into consideration a height direction position of the article, and thereby to stably take out the article in a short time. <P>SOLUTION: In the picking device 10 for taking out the article 1 stacked on a base 3 from the base 3, the articles 1 are stacked on the base 3 in a plurality of upper and lower stages. The picking device 10 is provided with a height detector 5 for detecting whether or not the height of the uppermost stage article 1 positioned at the uppermost stage of the articles 1 in the plurality of upper and lower stages is positioned at a predetermined article taking out height H; a lifting device 7 for lifting the base 3 and stopping lifting of the base 3 when the height detector 5 detects that the height of the uppermost stage article 1 is positioned at the article taking out height H during lifting of the base 3; and a taking out device 9 for taking out the uppermost stage article 1 positioned at the article taking out height H from the base 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a picking apparatus and method for taking out articles loaded on a table from the table.

  In the picking apparatus, when articles are stacked in a plurality of stages on a pallet or the like, the uppermost article (referred to as the uppermost article) is taken out from the pedestal and transferred to a predetermined location. Therefore, it is necessary to recognize the position in the height direction of the uppermost article. For example, in the case where the articles are stacked in a plurality of stages at different levels in a plurality of positions in the horizontal direction, the uppermost article at the high position and the uppermost article at the lower position are accurately grasped or recognized, It is necessary to take out the uppermost article.

The technique for that is described in the following patent documents 1 and 2, for example.
In Patent Document 1, a plurality of imaging units for recognizing articles on a pallet are provided, and the focal lengths of the plurality of imaging units are made different from each other. With this configuration, the imaging means to be used is switched according to the height of the uppermost box (article). Thereby, it is possible to accurately grasp or recognize the uppermost article.
In Patent Document 2, an automatic zoom function is added to an imaging unit that recognizes an article on a pallet, and the size of imaging data of the uppermost article is adjusted and made constant by the automatic zoom function. With this configuration, accurate imaging data is obtained. Thereby, it is possible to accurately grasp or recognize the uppermost article.
Japanese Patent Laid-Open No. 7-299782 JP 2002-13913 A

  In the case of Patent Document 1, since more imaging means are required, a lot of time is spent on maintenance of the imaging means. In addition, in order to select the imaging means, it is necessary to acquire the top height data of the article with some accuracy.

  In the case of Patent Document 2, an image pickup unit having an automatic zoom function is expensive, and it is necessary to perform a plurality of processes including a zoom operation in order to accurately grasp or recognize the uppermost article.

  As described above, in Patent Documents 1 and 2, the process of taking out the uppermost article is performed in consideration of the position in the height direction of the article, and there is a possibility that it takes time for the imaging means selection process, the automatic zoom process, and the like. .

  Therefore, an object of the present invention is to take out the uppermost article by means different from Patent Documents 1 and 2 and hardly consider the position in the height direction of the article, thereby stably and in a short time. It is an object of the present invention to provide a picking apparatus and method capable of taking out an article.

In order to achieve the above object, according to the present invention, there is provided a picking device for taking out an article loaded on a table from the table,
Articles are stacked in multiple stages on the table,
A height detector for detecting whether the height of the uppermost article among the upper and lower articles is positioned at a predetermined article removal height;
Elevating device that raises and lowers the table and stops the raising and lowering of the table when the height detector detects that the height of the uppermost article is located at the article extraction height during the raising and lowering of the table;
There is provided a picking device comprising: a take-out device for taking out an uppermost article located at the product take-out height from the table.

In the picking apparatus of the present invention described above, when taking out the uppermost article from the articles stacked in a plurality of stages on the base, the height of the uppermost article is the height of the article when the lifting device lifts the base. When the height detector detects that it is located at the removal height, the lifting device stops raising and lowering the table, and in this state, the lifting device 9 removes the uppermost article 1 at the height of the uppermost article 1. Take out. Therefore, the take-out device can take out the uppermost article without considering the position in the height direction of the article, and can take out the article stably and in a short time.
For example, when the take-out device has a take-out operation executing device that performs the take-out operation, the operation width in the vertical direction of the take-out operation executing device becomes narrow, so that the task speed can be increased and the take-out mechanism can be made inexpensive.

According to a preferred embodiment of the present invention, the take-out device is
An imaging device for acquiring image data of a region including the uppermost article located at the article extraction height;
An article recognition device that acquires recognition data of the uppermost article by performing image processing on the image data;
A take-out operation executing device for taking out the uppermost article from the table based on the recognition data.

As described above, when the recognition data of the uppermost article is acquired from the image data, the uppermost article in the image data is positioned at a certain article removal height, and therefore the following effects (1) to (5) are obtained. Is obtained.
(1) In the calibration of image processing, there is no need to consider the height direction.
(2) When the loading position of the article on the table is determined, the position of the top article is always at the same position, so that the range of image data to be processed can be set almost constant. Thus, the image processing time can be shortened.
(3) Image data can be acquired under a certain illumination condition, thereby stabilizing image processing.
(4) The image pickup apparatus picks up the area in the vertical direction from above the table, so that even when a plurality of uppermost articles are arranged in the same horizontal plane, an automatic zoom function or a plurality of image pickup apparatuses Can be recognized with high accuracy without requiring a plurality of articles in the image data.
(5) Since the position of the uppermost article is always almost the same position, the picking mechanism will not be missed when the takeout operation execution device takes out the uppermost article so that the uppermost article is not missed. The movement efficiency of the apparatus is improved.

According to the present invention, there is also provided an article picking method using the above-described picking apparatus,
(A) The uppermost article located at the article takeout height is taken out from the table by the takeout device,
(B) When (A) is completed, the lifting device raises the table, and the height of the new uppermost article is positioned at the article removal height while the table is raised. When the detector detects, it stops raising and lowering the platform,
(C) The picking method is characterized in that (A) and (B) are repeated in order until the take-out device takes out a desired number of uppermost articles.

  As described above, since (A) and (B) are repeated in order, when the desired number of uppermost articles are taken out, the uppermost article positioned at a constant article removal height can always be taken out. Therefore, a desired number of uppermost articles can be taken out by a stable take-out operation.

  According to the present invention described above, the uppermost article can be taken out with little consideration of the position in the height direction of the article, whereby the article can be taken out stably and in a short time.

  The best mode for carrying out the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

FIG. 1 is a configuration diagram of a picking apparatus 10 according to an embodiment of the present invention. The picking device 10 is a device that takes out the article 1 loaded on the table 3 from the table 3. The table 3 can be moved up and down, and the articles 1 are stacked in a plurality of stages on the table 3.
In the present embodiment, the articles 1 are stacked on the table 3 in a plurality of upper and lower stages at a plurality of locations in the horizontal direction. In FIG. 1, three rows of articles 1 stacked in a plurality of upper and lower stages at three positions in the left-right direction are provided in a direction perpendicular to the paper surface. That is, in this example, the articles 1 are stacked on the table 3 in a plurality of upper and lower stages at 3 × 3 = 9 locations.
The picking device 10 includes a height detector 5, a lifting device 7, and a take-out device 9.

  The height detector 5 detects whether or not the height of the uppermost article (hereinafter referred to as the uppermost article 1) among the upper and lower plurality of articles 1 is positioned at a predetermined article removal height H. .

  The elevating device 7 raises and lowers the table 3, and when the height detector 5 detects that the height of the uppermost article 1 is positioned at the article extraction height H during the raising and lowering of the table 3, the elevator 3 moves up and down. Stop.

  The take-out device 9 takes out the uppermost article 1 from the table 3 in a state where the uppermost article 1 is brought to the article removal height H by the height detector 5 and the lifting device 7.

  The picking device 10 according to the present embodiment will be described in more detail.

In the example of FIG. 1, the height detector 5 is reflected by a laser irradiation unit 5 a that irradiates a laser beam in a horizontal direction at a predetermined article extraction height H, and the laser beam reflected by the article 1 at the article extraction height H. And a laser detector 5b for detecting the reflected laser beam. When the laser irradiation unit 5a is in operation, the laser irradiation unit 5a swings around the vertical axis at a high speed, so that the uppermost article 1 can be detected at a plurality of locations in a direction perpendicular to the paper surface of FIG. . When the stage 3 is raised from a state where the height of the uppermost article 1 is lower than the article removal height H, and the laser detector 5b detects the reflected laser light during the rise, the height detector 5 A detection signal indicating that the height of the upper article 1 is located at the article removal height H is output.
According to the present invention, the height detector 5 is a device that can detect whether the height of the uppermost article 1 is located at a predetermined article removal height H and outputs the detection signal. Other configurations may be used. For example, the height detector 5 may be a device using a three-dimensional laser distance sensor disposed above the table 3 and two imaging devices. In the case of a three-dimensional laser distance sensor, it is possible to accurately detect whether the uppermost article 1 is positioned at the article removal height H even if the article 1 has an uneven upper surface. In an apparatus using two image pickup devices, two image pickup devices are arranged above the table 3 at intervals on the same horizontal plane so that the table 3 enters the field of view, and the uppermost article 1 in the image captured by each image pickup device. The height of the uppermost article 1 is detected based on the difference between the positions of the uppermost article 1.

  In the example of FIG. 1, the elevating device 7 is a pantograph type device using a spring or a cylinder, but may have other configurations. For example, a device that raises and lowers the table 3 by converting the rotary motion of the servo motor into a lifting motion, a device that raises and lowers the table 3 using a pneumatic cylinder or a hydraulic cylinder, and other suitable devices may be used. The elevating device 7 has an elevating mechanism 7a that moves the table 3 up and down and includes a drive source, and a control unit 7b that controls the operation of the elevating mechanism 7a. When the control unit 7b receives the detection signal from the height detector 5, the control unit 7b performs control to stop the lifting / lowering (up in the example of FIG. 1) of the lifting mechanism 7a. In FIG. 1, the elevating mechanism 7a has an elevating stage 11 on which the table 3 is loaded.

In the example of FIG. 1, the take-out device 9 includes an imaging device 13, an article recognition device 15, and a take-out operation execution device 17.
The imaging device 13 acquires image data of a region including the uppermost article 1 located at the article takeout height H. The imaging device 13 is fixed at a fixed position above the table 3 and is directed in the vertical direction, and images the region from above. The imaging device 13 may be a CCD camera.
The article recognition apparatus 15 acquires recognition data of the uppermost article 1 by performing image processing on the image data. The recognition data is data relating to the position and orientation (posture) of the uppermost article 1 in the horizontal plane at the article removal height H. The vertical distance between the imaging device 13 and the article removal height H is constant, and the article recognition device 15 performs the image processing on a certain range of image data (for example, a range corresponding to the upper surface of the table 3). Do. In this example, the plurality of articles 1 loaded on the table 3 have the same size and shape (for example, a rectangular parallelepiped). In this case, the article recognition device 15 extracts the dimension / shape data related to the dimension and shape of the uppermost article 1 in the image data by the image processing, and collates the dimension / shape data with the reference data for verification. Thus, if the two coincide, the uppermost article 1 is recognized, and the recognition data is obtained. The reference data for verification is reference data regarding the size and shape of the uppermost article 1 in the image data when the imaging device 13 acquires the image data including the uppermost article 1 at the article extraction height H. is there. Accordingly, since the uppermost article 1 having different heights in the image data has different dimensions, even when a plurality of uppermost articles 1 having different heights are included in the image data, the uppermost article 1 at the article extraction height H is included. Only the article 1 can be recognized. When a plurality of uppermost articles 1 exist at the article removal height H, recognition data is acquired for each uppermost article 1.
The take-out operation execution device 17 takes out the uppermost article 1 from the table 3 based on the recognition data. In this example, the take-out operation execution device 17 includes a control unit 17a and a take-out mechanism 17b including a drive source. The control unit 17a takes the uppermost article 1 from the table 3 based on the recognition data. The take-out mechanism 17b is controlled so as to transfer to a predetermined place. When there are a plurality of uppermost articles 1 at the article removal height H, the control unit 17a causes the takeout mechanism 17b to remove the uppermost articles 1 from the base 3 based on the plurality of recognition data. The take-out mechanism 17b is controlled so that it is transferred to a place one by one or a plurality of the uppermost articles 1 are simultaneously transferred from the table 3 to a predetermined place. The take-out mechanism 17b may be, for example, a robot arm having a grip portion that grips (for example, attracts) the uppermost article 1 at the tip and a plurality of joints.

  The table 3 is a pallet loaded on the lifting stage 11 of the lifting device 7. The pallet 3 on which a plurality of articles 1 are placed may be transported onto the lifting stage 11 by the conveyor 19. FIG. 2 shows the configuration in this case. FIG. 2B is a view taken along line BB in FIG. As shown in FIG. 2, the conveyor 19 has a pair of drive mechanisms 21 arranged in parallel at intervals, and each drive mechanism 21 meshes with a plurality of gears 21a to be rotated and these gears 21a. And an endless belt 21b that rotates in conjunction with the gear 21a. The lift stage 11 to be lifted / lowered has a size smaller than the distance between the pair of drive mechanisms 21, and is positioned between the pair of drive mechanisms 21. The operation of delivering the pallet 3 from the conveyor 19 to the elevating stage 11 is performed as follows. As shown in FIG. 2, the elevating stage 11 is lowered below the conveyor 19, and the pallet 3 is conveyed by the conveyor 19 to a position above the elevating stage 11. By raising the elevating stage 11 from this state, the pallet 3 is delivered from the conveyor 19 to the elevating stage 11. The height of the conveyor 19 is lower than the article extraction height H.

FIG. 3 is a flowchart showing a picking method using the picking apparatus 10 according to the above-described embodiment.
In step S <b> 1, the table 3 (pallet 3) on which the articles 1 are stacked in a plurality of stages is placed on the lifting stage 11 of the lifting device 7. This operation may be performed, for example, with the configuration of FIG. 2 described above.
In step S <b> 2, the elevating device 7 raises and lowers the table 3, and when the height detector 5 detects that the height of the uppermost article 1 is positioned at the article extraction height H while the table 3 is raised and lowered, Stop lifting 3 Thereby, the uppermost article 1 is positioned at the article removal height H. In this example, since the height of the uppermost article 1 at the time of completion of step S1 is lower than the article removal height H, the table 3 is raised in step S2, but the uppermost article at the time of completion of step S1. If the height of 1 is higher than the article removal height H, the table 3 is lowered in step S2. In this case, since it is necessary to move the conveyor 19 and the pallet 3 to a position where they do not interfere with each other, the height of the conveyor 19 is preferably equal to or lower than the height of the uppermost article 1. In addition, when the articles 1 are stacked in a plurality of upper and lower stages at a plurality of places on the base 3, in step S2, the highest article 1 positioned highest among the plurality of upper articles 1 is the article removal height H. When the height detector 5 detects that the base 3 is located, the elevation of the table 3 is stopped.
In step S3, the take-out device 9 performs a process and an operation for taking out the uppermost article 1 located at the article take-out height H from the table 3 to a predetermined place. Specifically, the image data is acquired by the imaging device 13, the recognition data of the uppermost article 1 located at the article extraction height H is acquired from the image data by the article recognition apparatus 15, and based on the recognition data. The take-out operation execution device 17 takes out the uppermost article 1 located at the article take-out height H from the table 3 to a predetermined place. When there are a plurality of uppermost articles 1 located at the article removal height H, the uppermost articles 1 are taken out one by one from the table 3 to a predetermined place, or a plurality of the uppermost articles 1 are placed. Are simultaneously taken out from the table 3 to a predetermined place.
In step S4, when the total number of the uppermost articles 1 taken out from the table 3 reaches a desired number, the picking operation is finished. On the other hand, when the total number of the uppermost articles 1 taken out from the table 3 does not reach the desired number, the process proceeds to step S5.
In step S <b> 5, the lifting device 7 raises the table 3, and when the height detector 5 detects that the height of the new uppermost article 1 is positioned at the article removal height H while the table 3 is being raised. The raising / lowering of the stand 3 is stopped. As a result, the next uppermost article 1 is positioned at the article removal height H. When step S5 is completed, the process returns to step S3.
In this way, Step 3 and Step S5 are sequentially repeated until the take-out device 9 takes out a desired number of uppermost articles 1.

Note that steps S3 to S5 may be performed automatically. In this case, when step S <b> 2 is completed, a signal indicating that is input to the extraction device 9. Thereby, the take-out device 9 starts step S3, and when step S3 is completed, the control device 23 of the picking device 10 compares the desired number with the total number of the uppermost article 1 taken out in step S3. In step S5, the determination is made. As a result, when it is determined that the desired number has not been reached, the control device 23 outputs a signal indicating that step S5 is performed to the lifting device 7. Thereby, step S5 is started, and when step S5 is completed, a signal indicating that is input to the take-out device 9. Thereby, the extraction device 9 starts step S3 again. Thereafter, the same processing / operation is repeated. The desired number is stored in the control device 23, and the total number is automatically counted by the control device 23 based on the processing / operation of the take-out device 9 in step S3.
On the other hand, steps S3 to S5 may be started manually. In this case, after completion of step S2, the person operates a predetermined operation device, whereby the take-out device 9 starts step S3. After completion of step S4, the person makes a determination in step S5. As a result, when the desired number has not been reached, step S5 is started by a person operating the operating device. After the completion of step S5, when the person operates the operating device, the take-out device 9 starts step S3 again. Thereafter, the same processing / operation is repeated.

In the picking apparatus 10 according to the above-described embodiment of the present invention, when the uppermost article 1 is taken out of the articles 1 stacked in the upper and lower stages on the table 3, the lifting device 7 moves the table 3 up and down. When the height detector 5 detects that the height of the upper article 1 is located at the article removal height H, the lifting device 7 stops the lifting and lowering of the table 3, and in this state, the lifting device 9 is the uppermost article 1. The uppermost article 1 at the height is taken out. Therefore, the take-out device 9 can take out the uppermost article 1 with little consideration of the position in the height direction of the article 1, and can thereby take out the article 1 stably and in a short time.
For example, since the operation width in the vertical direction of the take-out mechanism 17b is narrowed, the task speed can be increased and the take-out mechanism 17b can be made inexpensive.

Further, when the recognition data of the uppermost article 1 is acquired from the image data obtained by the imaging device 13, the uppermost article 1 in the image data is always located at a constant article removal height H. The effects (1) to (5) can be obtained.
(1) In the calibration of image processing, there is no need to consider the height direction.
(2) When the loading position of the article on the table 3 is determined, the position of the uppermost article 1 is always almost the same position, so that the range of image data for image processing can be set almost constant. Thus, the image processing time can be shortened.
(3) Image data can be acquired under a certain illumination condition, thereby stabilizing image processing.
(4) Since the imaging device 13 images the region in the vertical direction from above the table 3, even when a plurality of uppermost articles 1 are arranged in the same horizontal plane, A plurality of uppermost articles 1 in the image data can be accurately recognized without requiring the imaging device 13.
(5) Since the position of the uppermost article 1 is always substantially the same position, the uppermost article 1 is missed by the displacement of the takeout mechanism 17b when the takeout operation executing device 17 takes out the uppermost article 1. Therefore, the movement efficiency of the picking apparatus 10 is improved.

  Furthermore, since step S3 and step S5 are repeated in order, when the desired number of uppermost articles 1 are taken out, the uppermost article 1 positioned at a constant article removal height H can always be taken out. Therefore, a desired number of uppermost articles 1 can be taken out by a stable take-out operation.

  The present invention is not limited to the above-described embodiment, and various changes can be made without departing from the scope of the present invention.

It is a block diagram of the picking apparatus by embodiment of this invention. It is a block diagram in the case of conveying a pallet with a conveyor. 3 is a flowchart illustrating a picking method according to an embodiment of the present invention.

Explanation of symbols

1 article, 3 units (pallet), 5 height detector, 5a laser irradiation unit, 5b laser detection unit, 7 lifting device, 7a lifting mechanism, 7b control unit, 9 take-out device, 10 picking device, 11 lifting stage, 13 Imaging device, 15 article recognition device, 17 take-out operation execution device, 17a control unit, 17b take-out mechanism, 19 conveyor, 21 drive mechanism, 21a gear, 21b endless belt, 23 control device, H article take-out height,

Claims (3)

A picking device for picking up articles loaded on a table from the table,
Articles are stacked in multiple stages on the table,
A height detector for detecting whether the height of the uppermost article among the upper and lower articles is positioned at a predetermined article removal height;
Elevating device that raises and lowers the table and stops the raising and lowering of the table when the height detector detects that the height of the uppermost article is located at the article extraction height during the raising and lowering of the table;
A picking device comprising: a picking device for picking up an uppermost article located at the article picking height from the table. The take-out device is
An imaging device for acquiring image data of a region including the uppermost article located at the article extraction height;
An article recognition device that acquires recognition data of the uppermost article by performing image processing on the image data;
The picking device according to claim 1, further comprising: a take-out operation executing device that takes out the uppermost article from the table based on the recognition data. An article picking method using the picking apparatus according to claim 1 or 2,
(A) The uppermost article located at the article takeout height is taken out from the table by the takeout device,
(B) When (A) is completed, the lifting device raises the table, and the height of the new uppermost article is positioned at the article removal height while the table is raised. When the detector detects, it stops raising and lowering the platform,
(C) The picking method characterized by repeating (A) and (B) in order until the take-out device takes out a desired number of uppermost articles.

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