Article transfer apparatus

This article transfer apparatus comprises a disk member, an article supply apparatus which changes at least positions of the respective articles at a predetermined circumferential position of the rotating disk member, a rotation sensor which detects a rotational position of the disk member, a visual sensor which obtains information for identifying at least positions of the respective articles on the disk member, and a robot which picks up the articles on the disk member in a state in which the disk member is rotating, by using an article position information in which the information obtained by the visual sensor corresponds to a detected result of the rotation sensor at the time of obtaining the information, and a detected result of the rotation sensor at the time of picking up the articles.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on Japanese Patent Application No. 2016-100317 filed on May 19, 2016, the content of which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to an article transfer apparatus which picks up articles from an article group in order to transfer them to a predetermined transferred position.

As this kind of article transfer apparatus, an article transfer apparatus which measures exact positions of a plurality of articles housed in a box by a three-dimensional position-measuring apparatus and which picks up the articles in the box one by one by a robot arm according to the measurement result is known. (See PTL 1, for example.)

As another example of the article transfer apparatus, an article transfer apparatus having a plurality of robot arms located along a conveyer in order to pick up the plurality of articles transferred by the conveyer, wherein the robot arms includes robot arms located at the downstream side to pick up the articles which are not picked up by robot arms located at the upstream side, is known. (See PTL 2, for example.)

As another example of the article transfer apparatus, there is a known article transfer apparatus which comprises a rotating table, an article housing unit which is placed above a substantially circumferential half-area of the rotating table, a sensor which is provided above the other circumferential half-area of the rotating table and which detects positions of the articles on the rotating table, and a robot arm which picks up the articles on the other circumferential half-area of the rotating table one by one by using the detected result of the sensor, wherein a bottom surface of the article housing unit is consist of the rotating table and a gap through which the articles can pass is formed between a side surface of the article housing unit and the rotating table so that the articles in the article housing unit are gradually released to the other half-area of the rotating table. (See PLT 3, for example.)

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

An article transfer apparatus according to a first aspect of the present invention comprises a circulation conveyer which rotates along a predetermined circular-arc track in a state in which a plurality of articles are placed thereon; an article position change apparatus or member which changes at least positions of the respective articles on the circulation conveyer at a predetermined circumferential position of the rotating circulation conveyer; a rotational position detecting device which detects a rotational position of the circulation conveyer; a sensor which obtains information that enables identification of at least positions of the respective articles on the circulation conveyer at a position after passing through the predetermined position in the circumferential direction; and an article pick up device which picks up the articles placed on the circulation conveyer in a state in which the circulation conveyer is rotating and which transfers the picked-up articles to a predetermined transferred position by using article position information in which the information obtained by the sensor corresponds to a detected result of the rotational position detecting device at the time of obtaining the information by the sensor, and a detected result of the rotational position detecting device at the time of picking up the articles.

DESCRIPTION OF EMBODIMENTS

An article transfer apparatus in accordance with a first embodiment of the present invention is described below with reference to the drawings.

As shown inFIG. 1, this article transfer apparatus comprises a disk member10, as a circulation conveyer, which has a circular plate shape and which rotates at a state where a plurality of articles W are placed thereon, an article supply apparatus20, as an article position change means, which collects the articles W on the disk member10and which newly supplies articles W to the disk member10at a predetermined position in a circumferential direction of the rotating disk member10, a rotation sensor30, as a rotational position detecting means, which detects a rotational position of the disk member10, a visual sensor40which obtains information to identify a position and posture of each of the articles W on the disk member10at a position which is at a downstream side relative to a supply position of the articles W by the article supply apparatus20, and a robot50, as an article pick up means, which picks up the articles on the disk member10while the disk member10is rotating and which transfers the picked up articles W to a predetermined transferred position, the picking up is conducted at a position which is at a downstream side relative to the position for conducting the detection by the visual sensors40.

As shown inFIG. 2, the disk member10is configured to rotate in a clockwise direction, as shown inFIG. 1, by a driving device11such as a servo motor or the like, and the driving device11is controlled by a below-mentioned robot controller53. That is to say, the robot controller53controls the driving device11so that the disk member10can rotate at an arbitrary rotation speed.

The article supply apparatus20can use a known parts feeder. In this embodiment, the article supply apparatus20includes a container21which has a substantially circular shape in a plan view for housing the articles, and the container21comprises a bottom surface21a, side faces21b, and article feeding passages21cwhich are placed spirally in the side faces21b.

As shown inFIG. 2, the article supply apparatus has a vibration imparting device22provided with an electromagnet and a plate spring, for imparting vibration to the container21, an article feeding member23which feeds the articles W, which have reached the upper end of the article feeding passage21c, to the disk member10, and an article collecting member24which collects the articles W on the disk member10and drops the articles W to a middle side of the container21. The vibration imparting device22is controlled by the below-mentioned robot controller53.

The article feeding member23is placed above the disk member10so as to extend substantially in a radial direction of the disk member10. One end of the article feeding member23is placed outside in the radial direction of the disk member10, and is also placed at a position where the articles W are fed from the article feeding passage21c, and the other end of the article feeding member23is placed inside in the radial direction of the disk member10. The article feeding member23is formed by an L-shaped cross-section member, and comprises a bottom surface portion23awhich extends in a substantially horizontal direction, and side wall portion23bwhich extends upwardly from one end of the width direction of the bottom surface portion23aacross the entire longitudinal direction of the bottom surface portion23a. The one end of the bottom surface portion23ain the width direction is placed at a position which is at an upstream side of the rotation direction of the disk member10than the other side thereof.

The article collecting member24is placed above the disk member10so as to extend substantially in a radial direction of the disk member10. One end of the article collecting member24is placed outside in the radial direction of the disk member10, and is placed within the container21, and the other end of the article collecting member24is placed inside in the radial direction of the disk member10. The article collecting member24is formed by an L-shaped cross-section member, and comprises a bottom surface portion24awhich extends in a substantially a horizontal direction, and side wall portion24bwhich extends upwardly from one end of the width direction of the bottom surface portion24aacross the entire longitudinal direction of the bottom surface portion24a. The bottom surface portion24ais in contact with the upper surface of the disk member10, or placed adjacent to the upper surface of the disk member10. The one end of the bottom surface portion24ain the width direction is placed at a position which is at a downstream side of the rotation direction of the disk member10than the other side thereof.

With such configured article supply apparatus20, when the container21is vibrated by the vibration imparting device22, due to this vibration, the articles W in the container21are moved on the article feeding passage21ctoward the upper end side thereof. And, the articles W are moved to the article feeding member23from the upper end side of the article feeding passage21c, and are dropped to the upper surface of the disk member10from the article feeding member23. At this time, it is preferable that an inclination and a dimension of the article feeding member23should be set so that the articles W can be dropped to various positions of the disk member10in the radial direction.

On the other hand, since the bottom surface portion24aof the article collecting member24is in contact with the upper surface of the disk member10, or, it is placed adjacent to the upper surface of the disk member10, the articles W on the disk member10will be placed on the bottom surface23aof the article collecting member24by the rotation of the disk member10, and the transfer of the articles W toward the downstream side of the disk member10in the rotation direction will be limited by the side wall portions24bof the article collecting member24. Due to this, the articles W on the bottom surface portion24aare pushed toward the side of the container21by the articles W which are placed on the bottom surface portion24aone after the other, and therefore, the articles on the disk member10are housed in the container21. Note that the article collecting member24can be configured from the following elements: a plate-like member which is placed near the upper surface of the disk member10so as to extend in a radial direction of the disk member10, which prevents the articles W from moving by the rotation of the disk member10, and which is configured so that the articles W which have been previously prevented from being moved can be transferred outside in the radial direction of the disk member10by the articles W which are prevented from being moved one after the other; and a receiving member which receives the articles W dropped from the outer circumference portion of the disk member10by a plate-like member, and which returns the articles to the container21.

The rotation sensor, for example, can use a known encoder which applies light to a code wheel that is fixed to the outer circumferential surface of the disk member10, and which detects the rotational position of the disk member10by receiving the reflected light. A sensor which detects a rotational position of an axis of the servo motor, which is the driving device11, can be provided as the rotation sensor30. Also, a rotation frequency can be detected by providing a roller on a tip of a rotation axis of a pulse coder in order to push the roller against the outer circumferential surface of the disk member10, and by allowing the roller to rotate together with the disk member10. Or, the rotational position of the disk member10may be detected by connecting the driving device11and the pulse coder by a belt so that the rotation axis of the driving device11and that of the pulse coder can operate together, or by engaging gears thereof with each other.

The robot50has a robot body51which is supported by a frame50a, three robot arms52which are supported by the robot body51, and the robot controller53which controls the robot arms52.

As shown inFIG. 3, the visual sensor40has a two-dimensional imaging device41which captures images of the plurality of articles W on the disk member10, and a processor42. The images captured by the imaging device41are image-processed by the processor42, and information on the basis of the processed image is sent to the robot controller53which is placed in the robot50, and the robot controller53stores the information on the basis of the received processed image in a memory device54.

The processor42performs known image processing such as static thresholding process, dynamic thresholding process, or the like on the captured images, and stores the processed images in the image storage section42a. The processor42is a computer which has a CPU and a memory, and performs the image processing on the basis of a certain program stored in the memory. The processor42may send the processed images as information on the basis of the processed images to the robot controller53, or it may send location information of feature points (portions having distinctive shapes) of the plurality of articles shown in each of the processed images as information on the basis of the processed images to the robot controller53. In any of the cases, the information on the basis of the processed images is information for identifying a position and posture of each of the articles W.

The robot controller53operates on the basis of a program stored in the memory device54, and according to the information based on the processed images, the robot controller53discriminates articles which are located at positions capable of being picked up by the robot arms, and each of which has posture capable of being picked up by the robot arms. Also, the robot controller53controls the plurality of servo motors for moving the robot arms on the basis of this detected result, the information based on the processed images, reference posture information of article stored in the memory device54, and the detected result of the rotation sensor30during pick-up operation. By this, the articles W are picked up one by one by the respective robot arms, and the picked up articles are transferred to a predetermined transferred position. Here, a plurality of grip parts can be provided to the rip of the robot arms52, and in this case, a plurality of the articles W are picked up at one time or continuously by the robot arms from the disk member10, and the plurality of the received articles W are transferred to the predetermined transferred position.

Also, in this embodiment, the robot controller53is configured to operate based on the program so as to send control signals to the driving device11, the vibration imparting device22, the rotation sensor30, and the visual sensor40, and thereby controls these devices and the respective robot arms52. Also, the robot controller53is configured to receive the detected result of the rotation sensor30.

One example of the operation of the robot controller53is explained below with reference to a flowchart shown inFIG. 4. In this example, processed images are used as the information based on the processed images.

First, when an operator inputs, by a predetermined input device, an instruction for starting the transfer of the articles W by the robot50, and once the instruction is received by the robot controller53(step S1-1), the driving device11, the vibration imparting device22, the rotation sensor30, and the visual sensor40are started to operate (step S1-2). By this, the articles W are supplied to the rotating disk member10from the article supplying apparatus20.

Next, by the visual sensor, images of the articles W on the disk member10are captured with predetermined time intervals, or images of the articles W on the disk member10are captured every time the articles W move for a predetermined distance, and the robot controller receives the processed images from the processor42, and store information which corresponds to the detected result of the rotation sensor30at the time of image capturing in the memory device54(step S1-3). The information which corresponds the processed images stored in the memory device54and the detected result of the rotation sensor30is referred to as article position information. And, with respect to each of the processed images of each article position information stored with the predetermined time intervals or every time the articles W move for the predetermined distance, an article selection process which selects the articles at positions which are located on the disk member10and which are capable of being picked up by the robot arms52is started (step S1-4). At this time, the articles which match with the reference posture are selected prior to the other articles. For example, the processed images show thin images of the articles W when the articles W are in standing posture on the disk member10like the articles No. 1 to No. 3 that are shown inFIG. 1.

Also, like the other articles W shown inFIG. 1, even when the articles W are lying on the disk member10, the articles W face various directions, which can be seen in the processed images. In such cases, in the processed images of the article position information, when an article W is in posture which is between reference posture P1and reference posture P2shown inFIG. 5, such article W can be determined to match the predetermined reference posture. Together with the posture, it is also possible to determine whether the articles match a reference shape.

Yet, it is not the case that the determination whether the article match the reference posture is made only when comparing the article with the reference posture which is shown inFIG. 5. For example, at a detecting phase which detects whether the articles W are shown in processed images, and a position of the articles W when they are shown, when a fine or complex detection processing is conducted, the articles like the standing articles No. 1 to No. 3 can be detected as the article W, however, when a rough or simple detection processing is conducted, articles in the standing posture like the articles No. 1 to No. 3 cannot be detected as the article W. Also, with the laying articles, articles W which are being overlapped with each other, which are inclined, which are not facing intended directions, and the like may not be detected as the articles W. Therefore, conduct the detection of whether the articles W are shown in the processed images and of their positions if they are shown under a rough or simple predetermined condition, regard articles which are detected to be the articles W under such condition as the articles which match the reference posture and conduct processing on such articles. When selecting articles W which face an intended direction by using other method, such articles are detected as being matched with the predetermined reference posture.

Further, depending on kinds of the articles W, in the processed images of the article position information, it is possible to detect whether the articles W are laying with their face side up or their back side up, and in such case, it is possible to configure to preferentially select the articles W laying with their face side up.

In addition, with the processed images of the article position information, when more than two articles W approach with each other within a predetermined distance, or come into contact with each other, an assured pick-up by the robot arms52may be prevented, therefore, the articles W except for such articles are determined that they are at positions capable of being picked up.

Next, a robot arm control process which controls the plurality of servo motors respectively for operating the robot arms52is started based on the selection result of step S1-4, the processed images of the article position information, and the detected result of the rotation sensor30when conducting the pick-up operation which is to conduct an actual pick-up operation by the robot arms52(step S1-5). By this, at a state where the disk member10is rotating, the articles W are picked up one by one from the disk member10by the robot arms52, and the picked-up articles W are transferred to the predetermined transferred position.

At this time, due to the rotation of the disk member10, the articles W on the disk member10are transferred to the under part of the robot50from the lower part of the visual sensor40, however, the articles W are not moved relative to the disk member10. Due to this, the robot controller53can know a position and posture of each of the articles W on the disk member10based on the processed images of the article positon information and the detected result of the rotation sensor30. Thus, in step S1-5, the articles W on the disk member10can be picked up one by one by the robot arms52in a state where the disk member10is rotating. Note that, since the processed images are created with predetermined time intervals, or every time the articles W move for a predetermined distance, and the article position information in which the processed images correspond the current detected result of the rotation sensor30is created, the robot controller53use the processed images of the article position information which correspond with positions for conducting the pick-up operation by the robot arms.

In step S1-5, it is possible to configure the article transfer apparatus to pick up the articles W selected in step S1-4, which are determined to be at a position capable of being picked up, and to match the reference posture. By this, the pick-up efficiency of the robot arms52can be much improved.

Also, it is also possible to control the robot arms52by the robot controller53, so that the robot arms52can pick up the articles W, which allows a moving distance of the robot arms52to be short, prior to the other articles.

Then, for example, when an operator inputs, by a predetermined input device, an instruction for ending the transfer of the articles W by the robot50, and once the instruction is received by the robot controller53(step S1-6), the robot controller53ends the processing.

While the robot controller53is conducting the above process, the articles W which are not picked up by the robot arms52are housed in the container21, and the articles W housed in the container21is fed to the disk member10by the article feeding member23.

Also, in this embodiment, when a sufficient amount of the articles W is housed in the article supply apparatus20, the article supply apparatus20is configured so that it can supply, to the disk member10, articles W more than the amount being picked up by the robot arms52. That is, some of the articles W supplied to the disk member10by the article supply apparatus20are collected by the article collecting member24without being picked up by the robot arms. With this configuration, since an absolute amount of the articles W on the disk member10, which are easy to be picked up by the robot arms52, is increased, it is advantageous for shortening a time period required for picking up operation of the articles W.

Like this, in this embodiment, since the plurality of the articles W are placed on the disk member10, and positions of the articles W can be changed at the predetermined position in the circumferential direction, the information for detecting the positions of the articles W after their positions are changed is obtained by the visual sensor40, and the articles W on the disk member10are picked up by the robot arms52by using the information, every article W will be placed at its suitable position for being picked up by the robot arms after repeatedly rotating the disk member10and changing positions of the articles W.

Thus, due to the disk member10, it is not required to pick up every article W which is sent to the pick-up range of the robot arms, and the articles can be picked up sequentially from the articles which are easy to be picked up. Also, the articles W which are moved to the downstream side without being picked up will be picked up after changing the position and posture of each of the articles W by the article supply apparatus20. Therefore, it is unnecessary to provide other robot arms52in order to pick up the articles W which are moved to the downstream side without being picked up.

Moreover, since the articles W can be picked up sequentially from the articles which are easy to be picked up, it is unnecessary to provide a complex structure to the robot arms in order to pick up the articles W with bad pick-up conditions. And, it is also unnecessary to obtain exact location information, or the like of the respective articles W by the visual sensor40in order to pick up the articles W with the bad pick-up conditions by the robot arms with the complex structure, which can also reduce costs required for the visual sensor40.

In addition, when the articles W are not picked up by the robot arms52because of the articles W which are placed at positions that are too difficult for the robot arms to pick up, the positions of the articles W are changed by the article supply apparatus20, and the information that enables identification of the positions of the articles W is obtained by the visual sensor40, and the robot arms52pick up the articles W on the disk member10by using the information, therefore, it is unnecessary to pick up the articles W with bad pick-up conditions.

Furthermore, the robot arms52are controlled by the robot controller53so as to select the articles W to be picked up by the robot arms52on the basis of the article position information, and to pick up the selected articles W. Thus, the operation for picking up the articles W with bad conditions can be reduced or eliminated.

In addition, with the selection of the articles to be picked up, since the robot controller53is configured to select the articles W with posture which matches the predetermined reference posture from the article position information prior to the other articles, a time period required for the operation for picking up the articles W by the robot arms52can be shortened.

An article transfer apparatus in accordance with a second embodiment of this invention is described below with reference to the drawings.

As shown inFIG. 6, this embodiment is to provide an air blowing apparatus60at a predetermined circumferential position of the rotating disk member10instead of the article supply apparatus20in the first embodiment. An example of operations of the robot controller53with this configuration is described below with reference to a flow chart shown inFIG. 7.

First, the plurality of articles W are supplied to the disk member10by an operator or a robot, and the plurality of articles W are placed on the click member10. In this state, for example, when the operator inputs, by a predetermined input device, an instruction for starting the transfer of the articles W by the robot50, and once this instruction is received by the robot controller53(step S2-1), the driving device11, the rotation sensor30, and the visual sensor40are started to operate (step S2-2). At this time, the articles W may be supplied, for example, to a predetermined position of the disk member10in the circumferential direction by the operator or the robot on a regular basis.

Next, in a manner similar to or the same as step S1-3of the first embodiment, images of the articles W on the disk member10by the visual sensor40with predetermined time intervals, or every time the articles W move for a predetermined distance are captured, the processed images from the processor42with the predetermined time intervals, or every time the articles W move for the predetermined distance are received, and information which corresponds to the current detected result of the rotation sensor30is stored in the memory device54(step S2-3). And, in a manner similar to or the same as step S1-4of the first embodiment, with the processed images of the respective article position information which are stored with the predetermined time intervals or every time the articles W move for the predetermined distance, an article selection process which selects the articles at positions located on the disk member10, which are capable of being picked up by the robot arms52, is started (step S2-4).

Continuously, in a manner similar to or the same as step S1-5, a robot arm control process which controls the plurality of servo motors respectively for operating the robot arms52is started based on the selection result of step S2-4, processed images of the article position information, and the detected result of the rotation sensor30when conducting the pick-up operation which is to conduct an actual pick-up operation by the robot arms52(step S2-5).

Next, when an operator inputs, by a predetermined input device, an instruction for ending the transfer of the articles W by the robot50, and once the instruction is received by the robot controller53(step S2-6), the robot controller53ends the processing.

While the robot controller53conducts the above processing, a position or posture of each of the articles W on the disk member10are changed by the air blowing apparatus60at the predetermined circumferential position on the rotating disk member10. Due to this, as well as the first embodiment, in this embodiment, the articles W which are moved to the downstream side without being picked up can be picked up after changing the position and the posture of each of the articles W by the air blowing apparatus60. Therefore, this embodiment is also as effective as the first embodiment.

Moreover, in the first and the second embodiments, it is also possible to provide two robots50instead of providing one robot50. For example, as shown inFIG. 8, in the second embodiment, it is also possible to operate the two robots together by providing an upstream side robot50and a downstream side robot50and by connecting the controllers53of the two robots50with each other by a hub55.

In addition, step S1-4or step S2-4is conducted in the first and second embodiments, however, instead of conducting steps S1-4and S2-4, in steps S1-5and S2-5, the plurality of servo motors for operating the robot arms52may be controlled respectively based on the processed images of the article position information, and the detected result of the rotation sensor30when conducting the pick-up operation which is to conduct an actual pick-up operation by the robot arms52. Even in such case, the position and the posture of each of the articles W which are moved to the downstream side without being picked up are changed by the air blowing apparatus60, and a position and posture of each of the articles W are detected by the sensor40, and such articles W enter the pick-up area of the robot arms52again.

On the other hand, in step S1-4or step S2-4, a pick-up order of the articles W is decided, and in accordance with this order, the articles W can be picked up by the robot arms52. Thus, a time period required for the pick-up operation of the articles W can be much shortened.

Note that, in the first embodiment and the second embodiments, the two-dimensional imaging device41is used for the visual sensor40, however, a three-dimensional imaging device41may also be used. Furthermore, the robot arms52may be configured so that the robot arms52can pick up inclined articles W, and the robot arms52may also be configured so that the robot arms52can pick up inclined articles W based on information obtained by the visual sensor40by using the three-dimensional imaging device41.

Moreover, in the first and second embodiments, the disk member10is used as the circulation conveyer, however, instead of using the disk member10, a transfer device which has a plurality of plate-like members or stick-like members arranged along a predetermined circular-arc track, and the plurality of plate-like members or stick-like members rotate along the circular-arc track may be used so as to place the plurality of articles W on the transfer device. This is also as effective as the above description.

And, in the first embodiment, the article collecting member24is provided in order to house the articles W on the disk member in the container21, however, instead of using the article collecting member24, the articles W which pass through the pick-up area of the robot arms52can also be housed in the container21by using a dropping means which drops the articles W on the disk member10to a predetermined container, and by using an article collecting device which has an article transfer means for transferring the articles housed in the predetermined container to the container21, or the like.

Also, in the first embodiment, the article supply member23is provided in order to supply the articles W on the disk member10, however, as long as the articles W which are transferred to the upper end of the article feeding passage21ccan be dropped on the disk member10, other members or devices which have different shapes or configurations can be used.

Moreover, in the first and second embodiments, the article supply apparatus20or the air blowing apparatus60are used in order to change the position or the posture of each article W on the disk member, however, instead of the article supply apparatus20or the air blowing apparatus60, other members or devices which can change the position or the posture of each article W on the disk member can also be used. For example, it may be configured that a plurality of stick-like members which are arranged on the disk member10at an interval in the radial direction are provided instead of the air blowing apparatus60, and that the position or the posture of each articles W can be changed by the stick-like members coming in contact with the articles W on the disk member10.

REFERENCE SIGNS LIST

The aforementioned embodiments are included in the following aspects of the present invention.

An article transfer apparatus according to a first aspect of the present invention comprises a circulation conveyer which rotates along a predetermined circular-arc track in a state in which a plurality of articles are placed thereon; an article position change means which changes at least positions of the respective articles on the circulation conveyer at a predetermined circumferential position of the rotating circulation conveyer; a rotational position detecting means which detects a rotational position of the circulation conveyer; a sensor which obtains information that enables identification of at least positions of the respective articles on the circulation conveyer at a position after passing through the predetermined position in the circumferential direction; and an article pick up means which picks up the articles placed on the circulation conveyer in a state in which the circulation conveyer is rotating and which transfers the picked-up articles to a predetermined transferred position by using article position information in which the information obtained by the sensor corresponds to a detected result of the rotational position detecting means at the time of obtaining the information by the sensor, and a detected result of the rotational position detecting means at the time of picking up the articles.

With this aspect, since the plurality of articles are placed on the rotating circulation conveyer, positions of the articles are changed at the predetermined circumferential position, information which enables identification of positions of the articles after positions thereof are changed can be obtained by the sensor, and the articles on the circulation conveyer are picked up by the article pick up means by using the information, by repeatedly rotating the circulation conveyer and changing positions of the articles, every article will be placed at their suitable positions for being picked up by the article pick up means.

Due to this, it is unnecessary to pick up every article sent to a pick-up range of the article pick up means by the circulation conveyer, and therefore, the articles can be picked up sequentially from the articles which are easy to be picked up. Also, the articles W which are transferred to the downstream side without being picked up can be picked up after the positions thereof are changed by the article position change means. Therefore, it is not required to provide another article pick up means in order to pick up the articles which are transferred to the downstream side without being picked up.

Since the articles can be picked up sequentially from the articles which are easy to be picked up, it is not necessary to provide an article pick up means with a complex structure in order to pick up the articles with bad pick-up conditions, such as the articles placed at positions which are difficult for the article pick up means to pick up, and the like. Also, it is unnecessary to obtain exact position information or the like of the respective articles by a sensor in order to pick up the articles with the bad pick-up conditions by using the article pick up means with the complex structure, which can reduce costs for the sensor.

In the aforementioned aspect, it is preferable that positions of the articles, on the circulation conveyer, which are not picked up by the article pick up means are changed by the article position change means at the predetermined circumferential position.

With this configuration, when the articles are not picked up by the article pick up means since the articles are placed at positions which are difficult for the article pick up means to pick up, the positions of the articles will be changed by the article position change means, information which enables identification of positions of the articles will be obtained again by the sensor, and the articles on the circulation conveyer will be picked up by the article pick up means by using this information, therefore, it is unnecessary to pick up the articles with the bad conditions, such as the articles placed at positions which are difficult for the article pick up means to pick up, and the like.

In the aforementioned aspect, it is preferable that the article pick up means includes a robot arm for picking up the articles placed on the circulation conveyer, and a controller which executes an article selection process which selects articles to be picked up by the article pick up means based on the article position information, and a robot arm control process which controls the robot arm so as to pick up the articles selected by the article selection process.

With this configuration, since the articles to be picked up by the robot arm are selected by the article selection process, an operation for picking up the articles with the bad conditions, such as the articles placed at positions which are difficult for the article pick up means to pick up, and the like, can be reduced or eliminated.

In the aforementioned aspect, it is preferable that the information obtained by the sensor enables identification of a position or posture of each article on the circulation conveyer, and the controller is configured to select articles each having posture which matches a predetermined reference posture, prior to the other articles, using the article position information in the article selection process.

With this configuration, since the articles with the posture which matches with the reference posture are selected prior to the other articles, it is advantageous for shortening a time period necessary for operation for picking up the articles by the robot arms.

Advantageous Effects of Invention

According to the aforementioned aspects, it is possible to reduce manufacturing costs and improve transfer efficiency.10disk member11driving device20article supply apparatus21container22vibration imparting device23article feeding member24article collecting member30rotation sensor40visual sensor41imaging device42processor50robot51robot body52robot arms53robot controller54memory device60air blowing apparatus