JP2011056595A - Transfer hand and transfer robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transfer hand for preventing damage of the transfer hand and articles, completely holding the articles, and safely transferring without collapsing a posture of articles being transferred even when there is an error of position information in a Z axis direction based on image recognition. <P>SOLUTION: The transfer hand 3 is applied to the transfer robot 400 that transfers the article W based on three-dimensional position information of the article obtained by image recognition, and holds or releases the article W by expanding and contracting an interval of a plurality of holding bodies 5 provided at a hand body 4. The holding body 5 includes a housing part 51 and a movable part 52 to be configured to expand/contract. The movable part 52 inclines to the housing part 51 due to rattle with the article W held to abut to an inner face 51a of the housing part 51 in the holding direction. On the other hand, the movable part 52 separates from the inner face 51a of the housing part 51 in the holding direction with elastic force of an energizing member 53 with the article W released. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a transport robot that transports an article based on the three-dimensional position information of the article obtained by image recognition, and a transport hand used in the transport robot.

  As a transfer robot used in the article transfer device, as shown in Patent Document 1, a robot that is controlled (teaching control) by a predetermined operation procedure is the mainstream.

  In recent years, for example, as shown in Patent Document 2, three-dimensional position information of an article is acquired by image processing, and the conveyance robot is controlled based on the three-dimensional position information to convey the article while sandwiching it. Is considered.

  However, when acquiring three-dimensional position information by image recognition, the position accuracy in the Z-axis direction (height direction) in which the transport hand moves up and down is generally poor, and the article cannot be securely held by the transport hand. Or there exists a problem that a conveyance hand will be in contact with a mounting base and a conveyance hand will be damaged.

  In addition, if the position information acquired by image recognition differs from the actual position of the article due to the movement of the article after image recognition, etc., the article or the carriage hand may be damaged due to contact between the carriage hand and the article. There is also a problem of end.

  Furthermore, for example, when sandwiching an article in a tilted state such as being leaned against a wall, one of the fingers of the transport hand first contacts one of the placement surface or the wall, and more There is a problem that it cannot move and cannot hold the article, or the article is not sufficiently held.

Japanese Patent Laid-Open No. 2005-5608 JP 2006-130580 A

  Therefore, the present invention not only prevents the conveyance hand or the article from being damaged even if there is an error in the position information in the Z-axis direction due to the image recognition. The main objective of the present invention is to provide a transport hand that can be transported safely without breaking the posture of the article.

  That is, the transport hand according to the present invention is used in a transport robot that transports an article based on the three-dimensional position information of the article obtained by image recognition, and expands or contracts the intervals between a plurality of sandwiching bodies provided in the hand body. A holding hand that sandwiches or releases the article, wherein the sandwiching body is provided in the hand main body and slides along a sandwiching direction for sandwiching the article, and a sandwiching direction in the sandwiching body main body A movable part that is slidably movable along a direction substantially perpendicular to the movable part, and is interposed between the sandwiching body main body and the movable part, and biases the movable part in an opening direction. An urging member, and in a state in which the article is sandwiched, the movable portion is inclined with respect to the sandwiching body main body due to rattling and is in contact with the inner surface in the sandwiching direction of the sandwiching body main body. In a state in which the article is released while being fixed to the holding body, the biasing member separates the movable part from the inner surface in the holding direction of the housing part, thereby allowing the movable part to move relative to the holding body. It is characterized by releasing the fixation.

  In such a case, since the sandwiching body includes the sandwiching body main body and the movable part and expands and contracts, the position accuracy in the Z-axis direction by image recognition is poor, and the movable part is sandwiched even if the movable part contacts the mounting surface. The sliding movement with respect to the body body can alleviate the impact of the contact with the mounting surface and prevent the conveyance hand from being broken. In addition, even if the transport hand contacts the article due to a change in the position of the article before and after image recognition, the movable part slides relative to the sandwich body, so that the transport hand and the article can be prevented from being damaged. . Furthermore, since the movable part is fixed to the sandwiched body main body when the article is sandwiched with the sandwiched body main body contracted, the movable part slides relative to the sandwiched body main body after sandwiching the article. It is possible to solve the problem that the balance of the finished goods is lost and dropped. In addition, since the movable portion is configured to slide relative to the sandwich body, even in the case where the position accuracy in the Z-axis direction is poor due to image recognition, the movable portion is aligned in the Z-axis direction obtained by image recognition. If the transport hand is moved to a value obtained by adding a predetermined value, the article can be securely held regardless of the positional accuracy in the Z-axis direction by image recognition.

  In order to further secure the movable portion with respect to the sandwiching body main body, it is desirable that a slide prevention structure for preventing the movable portion from sliding is formed on the inner surface of the sandwiching body main body in the sandwiching direction. At this time, the slide prevention structure may be, for example, unevenness formed on the inner surface in the clamping direction, or may be configured by providing an adhesive member.

  In order to facilitate the pushing of the movable part to the sandwiching body main body after the article is released, it is desirable to further include a biasing member that biases the movable part toward the distal end side of the sandwiching body main body.

  In order to make it easier to push the movable part against the sandwich body after releasing the article, and to simplify the configuration and reduce the number of parts, the biasing member attaches the movable part in the opening direction. It is desirable that it is arranged so as to be biased toward the front end side of the sandwiching body main body.

  The urging member urges the holding body main body in the releasing direction. When the article is not held, the movable portion may be in contact with the inner surface of the holding body main body in the releasing direction. At this time, in order to facilitate the sliding movement of the movable part with respect to the sandwiching body main body, a slide allowing structure in which the movable part is slidably contacted is formed on the inner surface in the release direction of the sandwiching body main body. Is desirable.

  According to the present invention configured in this way, even if there is an error in the position information in the Z-axis direction by image recognition by actively using the rattling between the sandwich body main body and the movable part, In addition to preventing damage to the transport hand and the article, it is possible to provide a transport hand that can securely grip the article and can safely transport the article without losing the posture of the article.

It is a schematic diagram which shows the structure of the article conveyance apparatus which concerns on one Embodiment of this invention. It is a schematic diagram which shows the structure of a conveyance hand. FIG. 3 is a schematic cross-sectional view of the left holding body in FIG. 2 in a state where an article is held. FIG. 3 is a schematic cross-sectional view of the left holding body in FIG. 2 in a state where no article is held. It is a figure which shows the modification of a movable part. It is a figure which shows the modification of a clamping body. It is a figure which shows the modification of a clamping body.

  Hereinafter, an embodiment of an article conveying apparatus according to the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the article transporting apparatus 100 according to the present embodiment includes, for example, an imaging unit 200 that acquires images of a plurality of articles W housed in a box C having an opening at the top, and the imaging unit 200. An image recognition unit 300 that processes the obtained image data to recognize the image, a transport robot 400 for transporting the article W accommodated in the box C, and the image recognition data obtained by the image recognition unit 300 A control unit 500 having a CPU, a memory, and the like for acquiring three-dimensional position information of the article from the CPU and controlling the transfer robot. The article W of the present embodiment has a substantially rectangular parallelepiped shape, but is not limited to this.

  As an image recognition method, for example, when there is one imaging unit 200 and the shape of the article W is known in advance, the perspective distortion method is used. In addition, various methods such as a stereo method using two imaging units 200 or a laser cutting method can also be used.

  The transfer robot 400 of this embodiment is an articulated transfer robot, and has a transfer arm 2 having a multi-joint having degrees of freedom in at least the X axis, the Y axis, and the Z axis, and a transfer fixed to the tip of the transfer arm 2. And a hand 3. Note that the transfer robot 400 may be an orthogonal robot, a slack robot, or the like. In accordance with a control signal from the control unit 500, the transport arm 2 is configured so that the central axis L of the transport hand 3 coincides with the center of the upper surface of the article W and moves up and down along the vertical direction of the upper surface. 3 is moved.

  Therefore, as shown in FIG. 2, the transport hand 3 according to the present embodiment clamps or releases the article W by increasing or decreasing the interval between the plurality of sandwiching bodies 5 provided in the hand main body 4.

  The hand main body 4 has a substantially rectangular parallelepiped shape, and a plurality of sandwiching bodies 5 are extended on the lower surface thereof, and a rail (not shown) for expanding and contracting the sandwiching bodies 5 and on the rails And a drive mechanism (not shown) for slidingly moving the holding body 5. In the present embodiment, the transfer arm 2 is connected to the upper surface of the hand body 4.

  The sandwiching body 5 is provided on the lower surface of the hand body 4 and is slidably moved along a sandwiching direction (inward direction indicated by arrow A in FIG. 2) for sandwiching the article W, and the sandwiching body body 51. The movable part 52 is slidably moved along a direction substantially perpendicular to the clamping direction (Z-axis direction), and is interposed between the movable body 52 and the movable part 52 so as to be movable. And a biasing member 53 that biases the portion 52 in the release direction (the outward direction indicated by the arrow B in FIG. 2).

  The sandwiching body main body 51 is a hollow box having a substantially rectangular parallelepiped shape extending perpendicularly to the hand main body 4, and has an opening in the lower part, and a movable part 52 extends downward from the opening. Further, on the side wall of the sandwiching body main body 51, a slide long hole 51H is formed in which a projection 52P of the movable portion 52 described later slides. The long slide hole 51H defines a moving range of the movable portion 52.

  The movable part 52 has a substantially flat plate shape, and the sandwiching surface is flat. The movable portion 52 is accommodated in the sandwich body main body 51 and slides along the axial direction of the sandwich body main body 51 (a direction substantially perpendicular to the sandwich direction A). The movable portion 52 is housed in the holding body 51 with rattling, and is sandwiched between a state where the article W is sandwiched (see FIG. 3) and a state where the article W is not sandwiched (see FIG. 4). The posture with respect to the body main body 51 is different. Each state of the movable part 52 will be described later. As shown in FIG. 2, a protrusion 52 </ b> P for engaging the slide long hole 51 </ b> H formed in the sandwiching body main body 51 and guiding the movable portion 52 is provided on the side surface of the movable portion 52. The protrusion 52P is engaged with the slide long hole 51H with rattling.

  The urging member 53 urges an elastic force in the release direction B with respect to the movable portion 52 and urges the elastic force toward the distal end side (downward in the Z-axis direction in FIG. 2 and the like) of the sandwiching body main body 51. It is the arranged elastic member. Specifically, a spring 53 that is an elastic member is provided to be inclined with respect to the sliding direction (Z-axis direction) of the movable portion 52, and one end of the spring 53 is on the release direction side of the lower end portion of the sandwiching body main body 51. The other end is connected to the protrusion 52P of the movable part 52.

  Therefore, in the present embodiment, as shown in FIGS. 3 and 4, the inner surface 51 a in the sandwiching direction of the sandwich body 51 is provided with a slide prevention structure 511, and the inner surface 51 b in the release direction of the sandwich body 51 is slid. An allowance structure 512 is provided.

  The slide prevention structure 511 prevents the movable portion 52 from sliding in the Z-axis direction with respect to the sandwiching body main body 51 in a state where the article W is sandwiched. As shown in FIG. Are irregularities formed on the inner surface 51a. Specifically, the anti-sliding structure 511 is an uneven surface having a substantially serrated cross section. As the slide prevention structure 511, the movable portion 52 slides and moves by the vertical force received from the article W when the article W is sandwiched, the vertical elastic force received from the elastic member 53, and the gravity applied to the movable portion 52. Any structure having a coefficient of friction that does not occur is acceptable. The anti-sliding structure 511 may be configured using an adhesive member in addition to the uneven shape.

  The slide allowing structure 512 is a slide in the Z-axis direction with respect to the sandwiching body main body 51 of the movable part 52 in a state where the article W is opened (a state in which the movable part 52 is in contact with the inner surface 51b in the releasing direction of the sandwiching body main body 51 by the elastic member 53). It is allowed to move, has a smaller coefficient of friction than the slide prevention structure 511, and is configured to be slippery by, for example, surface treatment. In addition, you may comprise by the some roller provided rotatably on the inner surface 51b of a releasing direction. At this time, the rotation shaft of each roller is provided so as to be substantially orthogonal to the sliding direction of the movable portion 52.

  As shown in FIG. 3, the movable portion 52 receives a force directed from the article W in the release direction B in a state where the article W is sandwiched. As a result, the movable portion 52 rotates around a predetermined position due to rattling in the sandwich body 51, and the portion of the movable portion 52 accommodated in the sandwich body 51 moves in the sandwich direction A. The movable portion 52 is inclined toward the clamping direction with respect to the central axis C of the clamping body main body 51. Thereby, the upper end part of the movable part 52 contacts the slide prevention structure 511 of the clamping direction inner surface 51a of the clamping body main body 51. Thereby, the movable part 52 is fixed so as not to slide with respect to the sandwiching body main body 51.

  On the other hand, as shown in FIG. 4, the portion accommodated in the sandwiching body main body 51 of the movable portion 52 receives a force in the release direction B from the elastic member 53 in a state where the article W is not sandwiched. As a result, the movable portion 52 rotates around a predetermined position due to rattling in the sandwich body main body 51 and tilts toward the release direction with respect to the center axis C. As a result, the upper end portion of the movable portion 52 is separated from the slide prevention structure 511 and contacts the slide allowance structure 512. Further, the movable part 52 receives a force directed from the elastic member 53 in a direction substantially perpendicular to the sandwiching direction A (vertical downward), and the movable part 52 extends by sliding downward from the sandwiching body main body 51. The range in which the movable portion 52 extends is until the protrusion 52P provided on the movable portion 52 contacts the lower surface of the slide long hole 51H described above.

The operation of the article transport apparatus 100 configured as described above will be described.
The control unit 500 compares the three-dimensional position information of the article W obtained by the image recognition unit 300 with the position information of the transport hand 3, and controls the transport arm 2 so as to move the transport hand 3 to the article W. To do. At this time, regarding the height direction perpendicular to the upper surface of the article W, the conveyance arm 2 is controlled with a value obtained by adding a predetermined value to the distance in the height direction between the article W and the conveyance hand 3 as a movement distance. Here, the predetermined value is a range of accuracy error of position information in the height direction by image recognition, and is about 1 cm, for example. As a result, even if there is an error in the position in the height direction of the article W due to image recognition, the transport hand 3 can be reliably moved to the article W in the height direction. The transport hand 3 controlled in this way comes into contact with the placement surface of the article W. At this time, since the holding body 5 of the transport hand 3 is expanded and contracted by the movable portion 52, the transport hand 3 is not damaged even if it contacts the placement surface. Moreover, even if it contacts the article W, the conveyance hand 3 and the article W are not damaged.

  In addition, a contact sensor or the like may be provided in the sandwich body main body 51, an upper limit for inserting the movable portion 52 may be determined, and a case where the transport hand 3 is lowered too much may be detected. Thereby, the failure of the transport hand 3 can be prevented. In addition, when the control unit 500 receives the detection signal from the contact sensor and lowers the transport hand 3 too much, the control unit 500 determines that an error has occurred and acquires three-dimensional position information by image recognition again. Control.

  When the article W is clamped by the transport hand 3 moved as described above, the movable part 52 is inclined with respect to the sandwiching body main body 51, and the movable part 52 is fixed to the sandwiching body main body 51 by the slide prevention structure 511. Thereby, it can prevent that the movable part 52 slides with respect to the clamping body main body 51 during conveyance after clamping, and can prevent that the articles | goods W fall. After the article W is released after the conveyance, the movable portion 52 is separated from the slide prevention structure 511 by the spring 53, and the fixing to the holding body 51 is released. At the same time, the movable portion 52 contacts the slide allowing structure 512 and moves to the front end side of the sandwiching body main body 51 by gravity and the elastic force of the spring 53. That is, the movable part 52 extends from the sandwiching body main body 51.

<Effect of this embodiment>
According to the article transporting apparatus 100 according to the present embodiment configured as described above, the sandwiching body 5 is composed of the sandwiching body main body 51 and the movable portion 52, and therefore the position accuracy in the Z-axis direction due to image recognition is poor and the movable portion 52. Since the movable portion 52 slides with respect to the sandwiching body main body 51 even if the contact surface contacts the placement surface, the impact of the contact with the placement surface can be mitigated to prevent the conveyance hand 3 from being broken.

  Further, even if the transport hand 3 comes into contact with the article W due to a change in the position of the article W before and after the image recognition, the movable portion 52 slides with respect to the holding body 51, so that the transport hand 3 and the article W are damaged. Can also be prevented.

  Furthermore, when the article W is clamped in a state where the clamp body 5 is contracted, the movable portion 52 is fixed to the clamp body main body 51, so that the posture of the article W does not change during conveyance, and the article W It is possible to prevent the movable portion 52 from sliding with respect to the sandwiched body main body 51 after the product is sandwiched, and to solve problems such as the balance of the product W sandwiched and falling.

  In addition, since the movable portion 52 is configured to slide relative to the sandwiching body main body 51, the Z-axis obtained by the image recognition can be obtained even when the position accuracy in the Z-axis direction is poor due to the image recognition. If the transport hand 3 is moved to a value obtained by adding a predetermined value to the direction, the article W can be securely clamped regardless of the positional accuracy in the Z-axis direction by image recognition, and the movable part can be moved after clamping. Since 52 is fixed to the clamping body main body 51, it can be conveyed without changing the posture of the article W.

<Other modified embodiments>
The present invention is not limited to the above embodiment.

  For example, as shown in FIG. 5, a plurality of accommodating portions 521 may be provided on the clamping surface of the movable portion 52, and a plurality of protruding pieces 522 that can move forward and backward along the clamping direction may be provided on the accommodating portion 521. . The protruding piece 522 is housed with a backlash relative to the housing portion 521, and the rear end portion thereof is urged toward the front end side by a spring 523. In addition, a slide prevention structure 524 similar to that of the above-described embodiment is provided on the upper inner surface of the housing portion 521, and a slide allowing structure 525 is provided on the lower inner surface of the housing portion 521.

  In a state in which the article W is sandwiched, the protruding piece 522 receives a force from the article W in a vertically downward direction, so that the protruding piece 522 in the housing portion 521 moves upward and comes into contact with the slide prevention structure 524. On the other hand, in the state in which the article W is released, the protruding piece 522 is separated from the slide prevention structure 524 by the restoring force of the spring 523 and is most extended from the housing portion 521 by the elastic force of the spring 523.

  By providing the movable piece 52 with the protruding piece 522 that can move forward and backward in this manner, the article W in an inclined posture can be held as it is. Further, even if the article W is not easily held by a flat holding surface, such as an uneven surface, the protruding piece 522 moves and holds in accordance with the shape of the held surface, so that the article W can be securely attached. Can be held in.

  Further, the spring 53 of the embodiment is arranged so as to urge the movable body 52 with an elastic force in the release direction B and urge the elastic force toward the distal end side of the sandwiching body main body 51. 6, the first spring 53 a that biases the elastic force in the release direction B with respect to the movable body 52, and the second spring that biases the elastic force toward the distal end side of the sandwiching body main body 51 with respect to the movable body 52. A spring 53b may be provided. At this time, the first spring 53a is disposed along the release direction B (along the horizontal direction), and the second spring 53b is disposed along the direction substantially perpendicular to the release direction (along the vertical direction). .

  Furthermore, although the sandwiching body 5 has two left and right in the embodiment, it may have three or more.

  In addition, the sandwiching body main body of the above embodiment is configured to accommodate the entire circumferential direction of the movable portion 52, but as shown in FIG. The protrusion 52T may be housed and guided in a housing groove 51M provided in the sandwiching body main body 51 with rattling. At this time, the movable portion 52 is urged by the first spring 53a in the release direction, and the second spring is urged by the second spring toward the distal end side of the sandwiching body main body 51.

  In addition, in the above-described embodiment, the anti-slide structure is provided on the inner surface 51a in the holding direction. However, when the article is held, the upper end portion of the movable portion is pressed and brought into contact with the inner surface in the holding direction of the holding body. If this does not occur, the slide structure may not be provided.

  In addition, although the urging member of the embodiment uses an elastic member such as a spring, the same effect can be obtained even if a motor with a clutch is used as the urging member.

  In addition, it goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 100 ... Article conveying apparatus 200 ... Imaging part 300 ... Image recognition part 400 ... Conveying robot 500 ... Control part 3 ... Conveying hand 4 ... Hand main body 5 ... Holding body 51... Sandwiching body main body 51 a... Inner surface 51 b of sandwiching body main body 51 b. Part 53 ・ ・ ・ Biasing member

Claims (6)

Used for a transport robot that transports an article based on the three-dimensional position information of the article obtained by image recognition, and transports the article to be clamped or released by expanding or reducing the interval between a plurality of sandwiching bodies provided on the hand body. Hand,
The sandwich body is
A holding body provided on the hand body and slidingly moved along a holding direction for holding an article;
A movable part that is accommodated with rattling so as to be slidable along a direction substantially perpendicular to the clamping direction in the clamping body main body;
An urging member provided between the sandwiching body main body and the movable part and urging the movable part in an opening direction,
In a state where the article is sandwiched, the movable portion is tilted with respect to the sandwiching body main body due to rattling, contacts the inner surface in the sandwiching direction of the sandwiching body main body, and is fixed to the sandwiching body main body.
In a state where the article is opened, the biasing member releases the fixed portion of the movable portion with respect to the sandwiching body main body by separating the movable portion from the inner surface in the sandwiching direction of the sandwiching body main body. Characteristic transport hand.   The transport hand according to claim 1, wherein a slide prevention structure for preventing the movable portion from sliding is formed on an inner surface in a clamping direction of the clamping body.   The transport hand according to claim 1, further comprising an urging member that urges the movable portion toward a distal end side of the sandwiching body main body.   The transport hand according to claim 1 or 2, wherein the urging member urges the movable portion in an opening direction and is urged toward the distal end side of the sandwiching body main body.   The conveyance hand according to claim 1, 2, 3, or 4, wherein a slide allowing structure is formed on an inner surface of the holding body main body in a releasing direction so that the movable portion is slidably contacted.   A transfer robot having the transfer hand according to claim 1.