hand

Abstract

To improve the carrying performance of a hand placing an article on a base with a holder to carry.SOLUTION: A hand 10 is equipped with a base 3, a first holder 4 that is supported so as to move in a predetermined first direction X with respect to the base 3 and holds an article W, a first drive device 5 that moves the first holder 4 in the first direction X, and a second holder 6 that is disposed next to the first holder 4 in a second direction Z intersecting the first direction X, and is supported so as to move in the first direction X with respect to the base 3, and holds the article W. On the base 3, the article W held by the first holder 4 and the second holder 6 is placed. The second holder 6 is configured to adjust a distance to the first holder 4 in the second direction Z.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The technology disclosed herein relates to a hand.

Background Art

[0002] Conventionally, a hand having a holder for holding an article has been known. For example, Patent Document 1 discloses a hand having a holder for holding an article and a base on which the article is placed. This hand moves the holder holding the article in a predetermined direction and places the article on the base. The hand conveys the article while it is placed on the base.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The above-mentioned hand is configured to be able to hold articles of various sizes by expanding the holder. However, further improvement in the conveying ability of the hand is desired, and there remains room for further improvement in the hand as described above.

[0005] The technology disclosed herein has been made in view of such points, and the object thereof is to improve the conveying ability of a hand that places and conveys an article on a base by a holder.

Means for Solving the Problems

[0006] The hand disclosed herein comprises a base, a first retainer supported to be movable in a predetermined first direction relative to the base and for holding an article, a first drive device for moving the first retainer in the first direction, and a second retainer positioned alongside the first retainer in a second direction intersecting the first direction, supported to be movable in the first direction relative to the base and for holding an article, wherein the article held by the first and second retainers is placed on the base, and the second retainer is configured to be adjustable in distance from the first retainer in the second direction. [Effects of the Invention]

[0007] The aforementioned hand can improve transport capacity. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 shows the configuration of the robot system. [Figure 2] Figure 2 is a perspective view of the hand. [Figure 3] Figure 3 is a perspective view of the hand in a different state than that shown in Figure 2. [Figure 4] Figure 4 is a front view of the hand. [Figure 5] Figure 5 is a side view of the hand. [Figure 6] Figure 6 is a bottom view of the hand. [Figure 7] Figure 7 shows a schematic hardware configuration of the control unit. [Figure 8] Figure 8 is a functional block diagram of the control unit. [Figure 9] Figure 9 is a flowchart of the goods transfer process. [Modes for carrying out the invention]

[0009] Exemplary embodiments will be described in detail below with reference to the drawings. Figure 1 shows the configuration of the robot system 100.

[0010] The robot system 100 is a system for transporting goods. Here, we will describe the case of transporting goods W, which are stacked in a predetermined location, to a target location. The goods W are, for example, cardboard boxes. The robot system 100 comprises a robot 1 for transporting the goods W and a control device 2 for controlling the robot 1.

[0011] Robot 1 is, for example, an industrial robot. Robot 1 has a robot arm 11 and a hand 10 connected to the robot arm 11. In this example, robot 1 further has a transport vehicle 15 and an equipment housing 16. The robot arm 11 is mounted on the transport vehicle 15. The equipment housing 16 houses the equipment necessary for controlling robot 1, including a control device 2. Robot 1 moves autonomously using the transport vehicle 15.

[0012] The robot arm 11 changes the position and orientation of the hand 10. The robot arm 11 is a vertical articulated robot arm. The robot arm 11 has a plurality of links 12, joints 13 that connect the plurality of links 12, and servo motors 14 (see Figure 7) that rotate the plurality of joints 13. For example, a link 12 located at one end of the robot arm 11 is connected to the transport vehicle 15 via a joint 13 so as to be rotatable around a rotation axis extending in the vertical direction. The robot arm 11 may also be a horizontal articulated robot arm, a parallel link type, a Cartesian coordinate type, or a polar coordinate type robot arm, etc.

[0013] The hand 10 is the end effector of the robot arm 11. The hand 10 is connected to the tip of the robot arm 11. Specifically, the hand 10 is connected to the link 12 at the end of the multiple links 12 that is opposite to the link 12 connected to the transport vehicle 15. The hand 10 can assume various postures depending on the movement of the robot arm 11.

[0014] The transfer cart 15 moves the robot 1 on the floor surface or the like. The transfer cart 15 is not limited to one that travels by wheels and may have a traveling device such as a crawler. The transfer cart 15 may be an AGV (Automated Guided Vehicle) or the like.

[0015] The equipment housing part 16 houses, in addition to the control device 2, a negative pressure generating device 17 and an air supply device 18. The negative pressure generating device 17 generates a negative pressure in the suction pads 41 and 61 described later. For example, the negative pressure generating device 17 is a vacuum pump. The air supply device 18 pumps air. The air supply device 18 supplies air to the first fixed driving device 82, the second fixed driving device 83, etc. described later. For example, the air supply device 18 is an air pump. The negative pressure generating device 17 and the air supply device 18 are controlled by the control device 2.

[0016] Subsequently, the configuration of the hand 10 will be described in detail. FIG. 2 is a perspective view of the hand 10. FIG. 3 is a perspective view of the hand 10 in a state different from that of FIG. 2. FIG. 4 is a front view of the hand 10. FIG. 5 is a side view of the hand 10. FIG. 6 is a bottom view of the hand 10. Note that FIG. 2 shows a state in which the distance from the first holder 4 to the second holder 6 is maximum and the first holder 4 and the second holder 6 have advanced most forward. FIG. 3 shows a state in which the distance from the first holder 4 to the second holder 6 is minimum and the first holder 4 and the second holder 6 have retreated most backward.

[0017] The hand 10 includes a base 3, a first holder 4 for holding an article W, a first driving device 5, and a second holder 6 for holding the article. The first holder 4 is supported so as to be movable in a predetermined first direction X with respect to the base 3. The first driving device 5 moves the first holder 4 in the first direction. The second holder 6 is arranged side by side with the first holder 4 in a predetermined second direction Z and is supported so as to be movable in the first direction X with respect to the base 3. The article W held by the first holder 4 and the second holder 6 is placed on the base 3. The hand 10 holds the article W by the first holder 4 and the second holder 6, and places the article W on the base 3 by moving the first holder 4 and the second holder 6 in the holding state of the article W in the first direction X.

[0018] And the second holder 6 is configured to be able to adjust the distance from the first holder 4 in the second direction Z. That is, the second holder 6 is configured to be able to adjust the interval from the first holder 4 in the second direction Z. The hand 10 may further include a guide 7 that supports the second holder 6 so as to be movable in the second direction Z, and a second driving device 8 that moves the second holder 6 in the second direction Z. That is, the second holder 6 is guided in the second direction Z by the guide 7 and is moved in the second direction Z by the second driving device 8. Thereby, the distance of the second holder 6 from the first holder 4 in the second direction Z is adjusted.

[0019] In this example, the second direction Z is substantially orthogonal to the first direction X. Specifically, the second direction Z is the vertical direction. Also, a direction substantially orthogonal to both the first direction X and the second direction Z is defined as the third direction Y. Here, each of the first direction X, the second direction Z, and the third direction Y means a direction regardless of the orientation.

[0020] More specifically, the base 3 has a base plate 31 on which the article W held by the first retainer 4 is placed. In plan view, the base plate 31 has a substantially rectangular shape with the first direction X as the longitudinal direction and the third direction Y as the short direction. The thickness direction of the base plate 31 coincides with the second direction Z. The base plate 31 has an upper surface 31a and a bottom surface 31b facing opposite to the upper surface 31a. The base plate 31 also has two sliding plates 31c provided at both ends of the upper surface 31a in the third direction Y, extending in the first direction X. The sliding plates 31c have a mounting surface 31d on which the article W held by the first retainer 4 is placed. The mounting surface 31d faces the second direction Z, specifically upward. The mounting surface 31d has a relatively small coefficient of friction and functions as a sliding surface on which the article W slides.

[0021] As shown in Figure 5, an attachment 32 is provided at one end of the base plate 31 in the first direction X, to which the tip of the robot arm 11 is attached. The link 12 at the tip of the robot arm 11 is attached to the attachment 32. By moving the robot arm 11, the hand 10 can assume any desired posture.

[0022] For the sake of explanation, the configuration of the hand 10 will be described in the orientation where the thickness direction of the base plate 31, i.e., the second direction Z, is facing up and down. This orientation is the orientation in which the hand 10 is normally used and will be referred to as the basic orientation. In addition, in the first direction X, the attachment 32 is considered the rear, and the side opposite the attachment 32 is considered the front. That is, in the first direction X, the side away from the robot arm 11 is considered the front, and the side approaching the robot arm 11 is considered the rear.

[0023] Two rails 33 extending in a first direction X are provided on the upper surface 31a of the base plate 31. Blocks 34 are attached to each rail 33 so as to be movable in the first direction X, as shown in Figures 3 and 4. In other words, the rails 33 and blocks 34 form a linear guide that is slidable in the first direction X.

[0024] The first drive unit 5 includes a motor 51 and a transmission belt 52 that transmits the driving force of the motor 51. More specifically, the first drive unit 5 has two transmission belts 52.

[0025] Motor 51 is an electric motor capable of forward and reverse rotation. Motor 51 is mounted on the base plate 31. More specifically, as shown in Figures 2 and 5, motor 51 is located at the rear end of the base plate 31 in the first direction X. Motor 51 is positioned on the base 3 without protruding from the bottom surface 31b.

[0026] The transmission belt 52 is an endless belt. Each transmission belt 52 is wound around a drive roller 53 and a driven roller 54 provided on a base plate 31, as shown in Figure 5. Each pair of drive rollers 53 and driven rollers 54 are arranged side by side in a first direction X on the base plate 31. The drive roller 53 is located at the rear end of the base plate 31 in the first direction X, and the driven roller 54 is located at the front end of the base plate 31 in the first direction X. The axes of the drive roller 53 and the driven roller 54 extend in a third direction Y. The drive roller 53 and the driven roller 54 are provided on the base plate 31 so as to be rotatable around their respective axes. Specifically, the drive roller 53 and the driven roller 54 are each located in through holes formed in the base plate 31 in the thickness direction.

[0027] The driving force of the motor 51 is transmitted to the drive roller 53 via a reduction gear such as a gear train. The motor 51 is common to both drive rollers 53.

[0028] As shown in Figures 2 and 3, the transmission belt 52 extends in a first direction X along the upper surface 31a of the base plate 31, is wound around the drive roller 53, and turns towards the bottom surface 31b of the base plate 31 through the through hole, and as shown in Figure 6, extends in a first direction X along the bottom surface 31b, is wound around the driven roller 54, and turns towards the upper surface 31a of the base plate 31 through the through hole. As a result, the transmission belt 52 is positioned on the base plate 31 so as to extend along the base plate 31. The two transmission belts 52 are positioned side by side in a third direction Y.

[0029] The first retainer 4 is connected to the transmission belt 52. More specifically, the carriage 56 is fixed to the transmission belt 52. The carriage 56 is fixed to the portion of the transmission belt 52 that extends along the upper surface 31a. The carriage 56 is also fixed to the block 34. In other words, the carriage 56 is driven in the first direction X by the transmission belt 52 and is guided in the first direction X by the rail 33. The carriage 56 cannot move in the second direction Z or the third direction Y. The carriage 56 supports the first retainer 4.

[0030] As shown in Figure 2, the first retainer 4 includes a plurality of suction pads 41, a back plate 42 that supports the suction pads 41, and a support base 43 to which the back plate 42 is attached.

[0031] The support base 43 has a bottom wall 43a, a pair of support walls 43b provided on the bottom wall 43a, and a mounting plate 43c to which the back plate 42 is attached. As shown in Figure 5, the bottom wall 43a extends in the third direction Y with its thickness direction facing the second direction Z. The pair of support walls 43b are located at both ends of the bottom wall 43a in the third direction Y. The pair of support walls 43b extend in the second direction Z with their thickness direction facing the third direction Y. The mounting plate 43c is fixed to the bottom wall 43a and the pair of support walls 43b with its thickness direction facing the first direction X. The mounting plate 43c is located in front of the bottom wall 43a and the pair of support walls 43b.

[0032] The backplate 42 is attached to the mounting plate 43c with its thickness direction oriented in the first direction X.

[0033] The suction pad 41 is a hollow pad formed in a bellows shape. The suction pad 41 is deformable. The suction pad 41 is attached to the front-facing surface of the back plate 42. Multiple suction pads 41 are arranged in a matrix on the back plate 42. The suction pad 41 has an opening facing forward.

[0034] The suction pad 41 is connected to the negative pressure generator 17 via piping. The negative pressure generator 17 generates negative pressure, causing any object approaching or in contact with the opening of the suction pad 41 to be sucked in. Multiple suction pads 41 may be connected to the negative pressure generator 17 via a common piping system or via multiple independent piping systems. When multiple suction pads 41 are connected to the negative pressure generator 17 via multiple independent piping systems, the multiple suction pads 41 can be made to perform suction individually or in groups.

[0035] The carriage 56 supports the first retainer 4 configured in this manner so that it can move in the second direction Z, but cannot move in the first direction X and the third direction Y.

[0036] More specifically, as shown in Figure 2, the carriage 56 has a bottom wall 56a, a pair of support walls 56b provided on the bottom wall 56a, a pair of rails 56c fixed to the pair of support walls 56b, and a pair of blocks 56d slidably connected to the pair of rails 56c in a second direction Z.

[0037] A pair of support walls 56b are arranged side by side in the third direction Y with a gap between them, and their thickness direction is oriented in the third direction Y. Each support wall 56b extends in the second direction Z, i.e., vertically. Corresponding rails 56c are fixed to the support walls 56b. The rails 56c extend in the second direction Z. The rails 56c and blocks 56d form a linear guide that is slidable in the second direction Z. The pair of rails 56c and the pair of blocks 56d are positioned inside the pair of support walls 56b and outside the pair of support walls 43b of the support base 43 in the third direction Y.

[0038] A pair of blocks 56d are fixed to a pair of support walls 43b. Therefore, the pair of support walls 43b, i.e., the support base 43, can move in the second direction Z along the rail 56c. Since the first retainer 4 is fixed to the support base 43, the first retainer 4 can also move in the second direction Z.

[0039] Furthermore, as shown in Figure 5, the first retainer 4 and the carriage 56 are provided with a lifting device 9 that moves the first retainer 4 in the second direction Z, i.e., the vertical direction. The lifting device 9 is located on the bottom wall 43a behind the mounting plate 43c.

[0040] The lifting device 9 is an air cylinder. The lifting device 9 has a piston rod that extends in the second direction Z and is movable in the second direction Z. The lifting device 9 is fixed to the support base 43 of the first retainer 4, and the piston rod is fixed to the bottom wall 56a of the carriage 56. An air supply device 18 is connected to the lifting device 9 via an air tube. The air tube is equipped with a solenoid valve that switches the state of air supply to the lifting device 9. By switching the state of air supply, the lifting device 9 selectively moves the piston rod between a first position where the piston rod is retracted and a second position where the piston rod is extended. The first position is the position where the support base 43 is closest to the bottom wall 56a, and at this time the position of the first retainer 4 is the lowest position in the second direction Z. The second position is the position where the support base 43 is furthest from the bottom wall 56a, and at this time the position of the first retainer 4 is the highest position in the second direction Z.

[0041] Thus, the first retainer 4 is supported by the carriage 56 so as to be movable in the second direction Z, and is moved in the second direction Z by the lifting device 9.

[0042] The second retainer 6 is attached to the carriage 56 via a guide 7, as shown in Figure 2. The second retainer 6 has a plurality of suction pads 61 and a back plate 62 that supports the suction pads 61. The back plate 62 is positioned so that its thickness direction faces the first direction X.

[0043] The suction pad 61 is a hollow pad formed in a bellows shape. The suction pad 61 is deformable. The suction pad 61 is attached to the front-facing surface of the back plate 62. Multiple suction pads 61 are arranged in a matrix on the back plate 62. The suction pad 61 has an opening facing forward.

[0044] The suction pad 61 is connected to the negative pressure generator 17 via piping. The negative pressure generator 17 generates negative pressure, causing any object approaching or coming into contact with the opening of the suction pad 61 to be sucked in. Multiple suction pads 61 may be connected to the negative pressure generator 17 via a common piping system or via multiple independent piping systems. When multiple suction pads 61 are connected to the negative pressure generator 17 via multiple independent piping systems, the multiple suction pads 61 can be made to perform suction individually or in groups.

[0045] The first drive unit 5 moves the carriage 56 in the first direction X by moving the transmission belt 52 with the motor 51. This causes the first drive unit 5 to move the first retainer 4 in the first direction X. Since the second retainer 6 is also attached to the carriage 56 via the guide 7, the first drive unit 5 moves both the first retainer 4 and the second retainer 6 in the first direction X. The first drive unit 5 moves the first retainer 4 and the second retainer 6 between a predetermined first position and a second position further back than the first position in the first direction X. The first position is the position where the suction pad 41 of the first retainer 4 and the suction pad 61 of the second retainer 6 protrude forward in the first direction X beyond the front end of the base plate 31, as shown in Figures 2 and 5. The first position is the position where the first retainer 4 and the second retainer 6 perform the suction of the article W. The second position is, as shown in Figure 3, when the suction pads 41 and 61 are retracted behind the front end of the base plate 31 in the first direction X. The second position is the position when the article W held by the first retainer 4 and the second retainer 6 is placed on the base plate 31.

[0046] As shown in Figure 3, the transmission belt 52 has a conveying surface 52a on which the article W held by the first retainer 4 is placed. The conveying surface 52a is the outer circumferential surface of the transmission belt 52. Specifically, when the first retainer 4 is in the second position, a portion of the transmission belt 52 is exposed on the upper surface 31a of the base plate 31 in front of the first retainer 4. The outer circumferential surface of the portion of the transmission belt 52 that is located in front of the first retainer 4 on the upper surface 31a of the base plate 31 is the conveying surface 52a. In other words, the transmission belt 52 moves the conveying surface 52a together with the first retainer 4. The position of the conveying surface 52a in the second direction Z, i.e., its height in the vertical direction, is approximately the same as that of the mounting surface 31d. The coefficient of friction of the conveying surface 52a is greater than that of the mounting surface 31d.

[0047] As shown in Figure 4, the guide 7 includes a first movable body 71, a first guide 74 that supports the first movable body 71 so as to be movable in a second direction Z relative to the base 3, a second movable body 72 to which a second retainer 6 is provided, and a second guide 75 that supports the second movable body 72 so as to be movable in a second direction Z relative to the first movable body 71. In this example, the second retainer 6 is provided on the second movable body 72 via a third movable body 73 and a third guide 76. The second retainer 6 is attached to the third movable body 73. The third guide 76 supports the third movable body 73 so as to be movable in a second direction Z relative to the second movable body 72. The second movable body 72 is positioned above the first movable body 71. The third movable body 73 is positioned above the second movable body 72.

[0048] The first guide 74 has a pair of blocks 74a fixed to the support base 43 and a rail 74b slidably connected to the blocks 74a in a second direction Z.

[0049] A pair of blocks 74a are positioned inside a pair of support walls 43b of the support base 43 in a third direction Y. The blocks 74a are fixed to the upper ends of the corresponding support walls 43b. Two rails 74b are also positioned inside a pair of support walls 43b in a third direction Y. The rails 74b extend in a second direction Z. The blocks 74a and rails 74b form a linear guide that is slidable in the second direction Z. Here, since the blocks 74a are fixed to the support walls 43b, the rails 74b move in the second direction Z relative to the support walls 43b.

[0050] The first movable body 71 has a pair of support walls 71a and a connecting wall 71b that connects the pair of support walls 71a to each other.

[0051] The pair of support walls 71a are arranged side by side in the third direction Y with a gap between them, with their thickness direction facing the third direction Y. The pair of support walls 71a are positioned inside the two rails 74b in the third direction Y. Each support wall 71a extends in the second direction Z, i.e., vertically. Each support wall 71a is fixed to the corresponding rail 74b. The connecting wall 71b is fixed to the upper ends of the pair of support walls 71a. Since the pair of support walls 71a are fixed to the two rails 74b, the first moving body 71 moves integrally with the rails 74b in the second direction Z as the rails 74b move in the second direction Z.

[0052] The second guide 75 has a pair of rails 75a fixed to a pair of support walls 71a of the first movable body 71, and a pair of blocks 75b slidably connected to the pair of rails 75a in a second direction Z.

[0053] A pair of rails 75a are arranged side by side in a third direction Y with a gap between them. The pair of rails 75a are located inside a pair of support walls 71a in the third direction Y. Each rail 75a extends in a second direction Z, i.e., vertically. Each rail 75a is fixed to the corresponding support wall 71a. A pair of blocks 75b are also located inside the pair of support walls 71a in the third direction Y. The rails 75a and blocks 75b form a linear guide that is slidable in the second direction Z. Since the rails 75a are fixed to the support walls 71a, the blocks 75b move relative to the support walls 71a in the second direction Z.

[0054] The second movable body 72 has a pair of support walls 72a and a connecting wall 72b that connects the pair of support walls 72a to each other.

[0055] A pair of support walls 72a are arranged side by side in the third direction Y with a gap between them, with their thickness direction facing the third direction Y. The pair of support walls 72a are located inside a pair of blocks 75b in the third direction Y. Each support wall 72a extends in the second direction Z, i.e., vertically. Each support wall 72a is fixed to the corresponding block 75b. The lower end of each support wall 72a is fixed to the block 75b. The connecting wall 72b is fixed to the upper end of each support wall 72a. Since the pair of support walls 72a are fixed to the two blocks 75b, the second moving body 72 moves integrally with the blocks 75b in the second direction Z as the blocks 75b move in the second direction Z.

[0056] Here, as shown in Figure 2, the connecting wall 71b of the first movable body 71 is positioned offset from the pair of support walls 71a in the first direction X. Therefore, the support wall 72a, which is fixed to the block 75b and extends in the second direction Z, does not interfere with the connecting wall 71b.

[0057] The third guide 76 has a pair of rails 76a fixed to a pair of support walls 72a of the second movable body 72, and a pair of blocks 76b slidably connected to the pair of rails 76a in the second direction Z.

[0058] A pair of rails 76a are arranged side by side in a third direction Y with a gap between them. The pair of rails 76a are located inside a pair of support walls 72a in the third direction Y. Each rail 76a extends in a second direction Z, i.e., vertically. Each rail 76a is fixed to the corresponding support wall 72a. A pair of blocks 76b are also located inside the pair of support walls 72a in the third direction Y. The rails 76a and blocks 76b form a linear guide that is slidable in the second direction Z. Since the rails 76a are fixed to the support walls 72a, the blocks 76b move relative to the support walls 72a in the second direction Z.

[0059] The third movable body 73 has a pair of support walls 73a and a connecting wall 73b that connects the pair of support walls 73a to each other.

[0060] The pair of support walls 73a are arranged side by side in the third direction Y with a gap between them, with their thickness direction facing the third direction Y. The pair of support walls 73a are located inside the pair of blocks 76b in the third direction Y. Each support wall 73a extends in the second direction Z, i.e., vertically. Each support wall 73a is fixed to the corresponding block 76b. The connecting wall 73b is fixed to the upper ends of the pair of support walls 73a. Since the pair of support walls 73a are fixed to the two blocks 76b, the third movable body 73 moves integrally with the blocks 76b in the second direction Z as the blocks 76b move in the second direction Z.

[0061] Here, as shown in Figure 3, the connecting wall 72b of the second movable body 72 is positioned offset from the pair of support walls 72a in the first direction X. Therefore, the support wall 73a, which is fixed to block 76b and extends in the second direction Z, does not interfere with the connecting wall 72b.

[0062] Mounting plates 73c are connected to a pair of support walls 73a of the third movable body 73, as shown in Figures 2, 3, and 5. The thickness direction of the mounting plates 73c is oriented in the first direction X. The second retainer 6 is attached to the mounting plates 73c. ​​Specifically, the back plate 62 of the second retainer 6 is attached to the mounting plates 73c with its thickness direction oriented in the first direction X.

[0063] As shown in Figure 4, the second drive unit 8 includes a variable drive unit 81 that can adjust the amount of movement of the second retainer 6, a first fixed drive unit 82 that moves the second retainer 6 by a fixed amount of movement, and a second fixed drive unit 83 that moves the second retainer 6 by a fixed amount of movement. The variable drive unit 81 drives the first movable body 71. The first fixed drive unit 82 drives the second movable body 72. The second fixed drive unit 83 drives the third movable body 73.

[0064] The variable drive unit 81 is an electric cylinder. Specifically, the variable drive unit 81 has a motor 81a and a rod 81b. The rod 81b extends in a second direction Z. The rod 81b has a ball screw mechanism that is rotationally driven by the motor 81a. When the motor 81a is operated, the rod 81b moves in the second direction Z. The motor 81a of the variable drive unit 81 is fixed to the carriage 56. The rod 81b is fixed to the connecting wall 71b of the first movable body 71. The variable drive unit 81 moves the first movable body 71 in the second direction Z by operating the motor 81a.

[0065] The variable drive device 81 continuously adjusts the position of the rod 81b in the second direction Z, i.e., the amount of extension, within a predetermined adjustable range by adjusting the amount of rotation of the motor 81a. In other words, the variable drive device 81 adjusts the amount of movement of the first moving body 71 in the second direction Z within an adjustable range by adjusting the amount of rotation of the motor 81a.

[0066] The first fixed drive unit 82 is an air cylinder. The first fixed drive unit 82 has a piston rod 82a. The piston rod 82a extends in the second direction Z. The first fixed drive unit 82 moves the piston rod 82a in the second direction Z. The first fixed drive unit 82 is fixed to the connecting wall 71b of the first movable body 71. The piston rod 82a is fixed to the connecting wall 72b of the second movable body 72.

[0067] An air supply device 18 is connected to the first fixed drive device 82 via an air tube. The air tube is equipped with a solenoid valve that switches the air supply state to the first fixed drive device 82. By switching the air supply state, the first fixed drive device 82 selectively moves the piston rod 82a between a first position where the piston rod 82a is retracted and a second position where the piston rod 82a is extended. The first fixed drive device 82 moves the second moving body 72 in a second direction Z relative to the first moving body 71 by moving the piston rod 82a between the first and second positions. The amount of movement of the piston rod 82a, i.e., the amount of movement of the second moving body 72, is constant at a first distance between the first and second positions. For example, the first distance is less than or equal to the maximum amount of movement of the first moving body 71 by the variable drive device 81.

[0068] The second fixed drive unit 83 has the same configuration as the first fixed drive unit 82. The second fixed drive unit 83 is an air cylinder having a piston rod 83a. The second fixed drive unit 83 is fixed to the connecting wall 72b of the second movable body 72. The piston rod 83a is fixed to the connecting wall 73b of the third movable body 73.

[0069] An air supply device 18 is connected to the second fixed drive device 83 via an air tube, and air is supplied to it independently of the first fixed drive device 82. The second fixed drive device 83 selectively moves the piston rod 83a in the second direction Z between a first position where the piston rod 83a is retracted and a second position where the piston rod 83a is extended, by switching the air supply state. The second fixed drive device 83 moves the third moving body 73 in the second direction Z relative to the second moving body 72 by extending or retracting the piston rod 83a between the first and second positions. The amount of movement of the piston rod 83a, i.e., the amount of movement of the third moving body 73, is constant at the second distance between the first and second positions. For example, the second distance is less than or equal to the maximum amount of movement of the first moving body 71 by the variable drive device 81.

[0070] The second drive unit 8 moves the second retainer 6 in the second direction Z by using the variable drive unit 81, the first fixed drive unit 82, and the second fixed drive unit 83 interchangeably. The second drive unit 8 operates each of the variable drive unit 81, the first fixed drive unit 82, and the second fixed drive unit 83 independently.

[0071] More specifically, the second drive unit 8 moves the first movable body 71 in the second direction Z by adjusting the amount of extension of the rod 81b of the variable drive unit 81. The second movable body 72 is supported by the first movable body 71, the third movable body 73 is supported by the second movable body 72, and the second retainer 6 is attached to the third movable body 73. Therefore, when the first movable body 71 moves in the second direction Z, the second movable body 72, the third movable body 73, and the second retainer 6 move in the second direction Z together with the first movable body 71. The second drive unit 8 can arbitrarily adjust the amount of movement of the first movable body 71 in the second direction Z, and consequently the amount of movement of the second retainer 6, within the adjustable range of the extension of the rod 81b.

[0072] The second drive unit 8 moves the second mobile body 72 in the second direction Z by changing the amount of extension of the piston rod 82b of the first fixed drive unit 82. The second drive unit 8 selectively switches the position of the piston rod 82b of the first fixed drive unit 82 between the first position and the second position. When the piston rod 82b is in the first position, the second mobile body 72 is closest to the first mobile body 71 in the second direction Z. On the other hand, when the piston rod 82b is in the second position, the second mobile body 72 is furthest from the first mobile body 71 in the second direction Z. When the second mobile body 72 moves in the second direction Z, the third mobile body 73 and the second retainer 6 move in the second direction Z together with the second mobile body 72. The second drive unit 8 moves the second movable body 72, and consequently the second retainer 6, by a certain first distance in the second direction Z, by switching the position of the piston rod 82b between the first position and the second position.

[0073] The second drive unit 8 moves the third movable body 73 in the second direction Z by changing the amount of extension of the piston rod 83b of the second fixed drive unit 83. The second drive unit 8 selectively switches the position of the piston rod 83b of the second fixed drive unit 83 between the first position and the second position. When the piston rod 83b is in the first position, the third movable body 73 is closest to the second movable body 72 in the second direction Z. On the other hand, when the piston rod 83b is in the second position, the third movable body 73 is furthest from the second movable body 72 in the second direction Z. When the third movable body 73 moves in the second direction Z, the second retainer 6 moves in the second direction Z together with the third movable body 73. By switching the position of the piston rod 83b between the first position and the second position, the second drive unit 8 moves the third movable body 73, and consequently the second retainer 6, by a certain second distance in the second direction Z.

[0074] The distance from the first retainer 4 to the second retainer 6 in the second direction Z is the minimum when the extension amount of the rod 81b of the variable drive device 81 is at its minimum, the piston rod 82b of the first fixed drive device 82 is in the first position, and the piston rod 83b of the second fixed drive device 83 is in the first position. Here, the distance from the first retainer 4 to the second retainer 6 in the second direction Z is defined as the distance in the second direction Z between the center of gravity of the front shape of the first retainer 4 and the center of gravity of the front shape of the second retainer 6. The distance from the first retainer 4 to the second retainer 6 in the second direction Z is the maximum when the extension amount of the rod 81b of the variable drive device 81 is at its maximum, the piston rod 82b of the first fixed drive device 82 is in the second position, and the piston rod 83b of the second fixed drive device 83 is in the second position. The second drive unit 8 adjusts the distance from the first retainer 4 to the second retainer 6 in the second direction XZ between the minimum distance and the maximum distance by appropriately combining the variable distance set by the variable drive unit 81, the first distance set by the first fixed drive unit 82, and the second distance set by the second fixed drive unit 83.

[0075] Here, since both the first distance and the second distance are less than or equal to the maximum movement amount of the first moving body 71 by the variable drive device 81, the distance from the first retainer 4 to the second retainer 6 in the second direction XZ can be adjusted over the entire range between the minimum distance and the maximum distance.

[0076] The hand 10 further includes an imaging device 19. The imaging device 19 is located on the upper part of the mounting plate 43c. The imaging device 19 is positioned between the first holder 4 and the second holder 6 in the second direction Z. The imaging device 19 is, for example, a stereo camera. The orientation of the imaging device 19 is generally towards the front in the first direction X. The imaging device 19 may also be a monocular camera or a TOF (Time-of-Flight) camera, etc.

[0077] As shown in Figure 5, the piping to the first retainer 4, the piping to the second retainer 6, the wiring to the variable drive unit 81, the piping to the first fixed drive unit 82, the piping to the second fixed drive unit 82, and the wiring to the imaging device 19 are housed in a housing duct 35, at least in the hand 10. The housing duct 35 is flexible and can accommodate the piping and cables. The housing duct 35 may also accommodate piping and wiring other than those described above. For example, the aforementioned piping and wiring are laid along the robot arm 11 and connected to corresponding devices such as the control device 2, the negative pressure generator 17, or the air supply device 18. In the hand 10, the piping and wiring, such as the piping to the first retainer 4, the piping to the second retainer 6, and the wiring to the drive unit 81, are arranged on the base 3 so as not to protrude from the bottom surface 31b. That is, the housing duct 35 is arranged on the base 3 so as not to protrude from the bottom surface 31b. Note that the housing duct 35 is not shown in any figure other than Figure 5.

[0078] The control device 2 causes the robot 1 to transfer the item W. The control device 2 controls the robot 1 to move the transport vehicle 15, robot arm 11, and hand 10, causing the hand 10 to hold the item W. The control device 2 moves the hand 10, which is holding the item W, using the transport vehicle 15 and robot arm 11 to transfer the item W to the target position.

[0079] Figure 7 shows a schematic hardware configuration of the control device 2. The control device 2 controls the servo motor 14 of the robot arm 11, the first drive unit 5, the second drive unit 8 and the lifting device 9 of the hand 10, the transport vehicle 15, the negative pressure generator 17, the air supply device 18, and the imaging device 19. The control device 2 includes a control unit 21, a storage unit 22, a memory 23, and a servo amplifier 24.

[0080] The control unit 21 controls the entire control device 2. The control unit 21 performs various calculation processes. For example, the control unit 21 is formed by a processor such as a CPU (Central Processing Unit). The control unit 21 may also be formed by an MCU (Micro Controller Unit), MPU (Micro Processor Unit), FPGA (Field Programmable Gate Array), PLC (Programmable Logic Controller), etc.

[0081] The storage unit 22 stores programs and various data executed by the control unit 21. The storage unit 22 is made up of non-volatile memory, an HDD (Hard Disk Drive), or an SSD (Solid State Drive), etc. The memory 23 temporarily stores data, etc. For example, the memory 23 is made up of volatile memory.

[0082] The servo amplifier 24 receives commands from the control unit 21 and supplies current to the servo motor 14. The servo amplifier 24 receives the detection result of the encoder 14a provided on the servo motor 14 as input. The servo amplifier 24 provides feedback control to the current applied to the servo motor 14 based on the detection result of the encoder 14a.

[0083] Figure 8 is a functional block diagram of the control unit 21. The control unit 21 realizes various functions by reading control programs from the storage unit 22 into memory and processing them. Specifically, the control unit 21 includes a travel control unit 25, an arm control unit 26, an imaging control unit 27, an image processing unit 28, a lifting control unit 29, a belt control unit 210, and a suction control unit 211.

[0084] The travel control unit 25 controls the transport vehicle 15. By controlling the rotation of the motor of the transport vehicle 15, the travel control unit 25 moves the transport vehicle 15, and by extension the robot 1, to the desired position.

[0085] The arm control unit 26 controls the movement of the robot arm 11 to move the hand 10 to a position according to the purpose, such as imaging the object W, holding the object W, or transporting the object W. The arm control unit 26 also performs actions such as selecting the object W to hold from among multiple objects W. The arm control unit 26 generates command angles for each joint 13 according to the target movement of the robot arm 11 and outputs the generated command angles to the servo amplifier 24.

[0086] The imaging control unit 27 controls the imaging device 19 to cause the imaging device 19 to perform imaging.

[0087] The image processing unit 28 processes the image captured by the imaging device 19 to determine the shape, position, or orientation of the item W. Specifically, the image processing unit 28 compares the captured image with a template of the item W stored in the storage unit 22 and extracts the item W from the captured image using a method such as pattern matching. The image processing unit 28 outputs the extracted shape, position, or orientation of the item W to the arm control unit 26 and the lifting control unit 29. The arm control unit 26 and the lifting control unit 29 utilize the extracted position or orientation of the item W in their respective control operations.

[0088] The lifting control unit 29 controls the second drive unit 8 and the lifting device 9 of the hand 10. Specifically, when adjusting the distance from the first retainer 4 to the second retainer 6 in the second direction Z, the lifting control unit 29 controls the second drive unit 8. On the other hand, when moving the first retainer 4 or the second retainer 6 as a whole in the second direction Z, the lifting control unit 29 controls the lifting device 9.

[0089] The belt control unit 210 controls the first drive unit 5 of the hand 10. Specifically, the belt control unit 210 adjusts the positions of the first retainer 4 and the second retainer 6 in the first direction X by controlling the rotation direction and amount of rotation of the motor 51 of the first drive unit 5.

[0090] The suction control unit 211 controls the operation of the first retainer 4 and the second retainer 6. Specifically, the suction control unit 211 switches the operation of the negative pressure generator 17 on and off, and also switches the conductivity between the negative pressure generator 17 and the first retainer 4 or the second retainer 6. As a result, the suction control unit 211 switches between applying suction to the first retainer 4 and the second retainer 6 and releasing it.

[0091] Next, we will specifically explain the transfer of items W by the robot system 100. Figure 9 is a flowchart of the transfer of items W. Here, we will explain using the example of transferring multiple items W stacked at a predetermined starting position to a predetermined destination position.

[0092] First, in step S101, the travel control unit 25 controls the transport vehicle 15 to move the robot 1 to the starting position.

[0093] Next, in step S102, the arm control unit 26 operates the robot arm 11 to move the imaging device 19 to a predetermined imaging position, and the imaging control unit 27 instructs the imaging device 19 to perform imaging. As a result, the imaging device 19 acquires images of the stacked objects W.

[0094] Next, in step S103, the image processing unit 28 extracts the outline, position, and orientation of the article W from the captured image.

[0095] Subsequently, in step S104, the arm control unit 26 selects an item W to be held by the hand 10 from among a plurality of items W, based on the extraction results of the image processing unit 28. Here, the hand 10 holds two items W stacked vertically together. For example, the arm control unit 26 selects the topmost item W and the item W immediately below it as the two items W to be held from among a plurality of items W.

[0096] In step S105, the lifting control unit 29 determines the distance from the first retainer 4 to the second retainer 6 in the second direction Z (hereinafter referred to as the "target distance"). The lifting control unit 29 determines the target distance based on the size and position of the two selected articles W. For example, the lifting control unit 29 finds the distance in the second direction Z between the centers of gravity of the frontal shapes of the two articles W, and sets the determined distance as the target distance.

[0097] The lifting control unit 29 determines the combination of second drive devices 8 to achieve the target distance. Specifically, if the target distance falls within the range obtained by adding the minimum distance from the first retainer 4 to the second retainer 6 to the adjustable distance of the variable drive device 81, the lifting control unit 29 positions the piston rod 82b of the first fixed drive device 82 to the first position and the piston rod 83b of the second fixed drive device 83 to the first position. In this state, the lifting control unit 29 adjusts the extension amount of the rod 81b of the variable drive device 81 to match the distance from the first retainer 4 to the second retainer 6 to the target distance. Note that in the hand 10 of Figure 3, the piston rods 82b and 83b are in the first position. If the target distance falls within the range obtained by adding the first distance of the first fixed drive unit 82 and the adjustable distance of the variable drive unit 81 to the minimum distance from the first retainer 4 to the second retainer 6, the lifting control unit 29 positions the piston rod 82b of the first fixed drive unit 82 to the second position and the piston rod 83b of the second fixed drive unit 83 to the first position. In this state, the lifting control unit 29 adjusts the amount of extension of the rod 81b of the variable drive unit 81 to match the distance from the first retainer 4 to the second retainer 6 to the target distance. Note that in the hand 10 of Figure 5, the piston rod 82b is in the second position and the piston rod 83b is in the first position. If the target distance falls within the range obtained by adding the first distance of the first fixed drive unit 82, the second distance of the second fixed drive unit 83, and the adjustable distance of the variable drive unit 81 to the minimum distance from the first retainer 4 to the second retainer 6, the lifting control unit 29 positions the piston rod 82b of the first fixed drive unit 82 to the second position and the piston rod 83b of the second fixed drive unit 83 to the second position. In this state, the lifting control unit 29 adjusts the extension amount of the rod 81b of the variable drive unit 81 to match the distance from the first retainer 4 to the second retainer 6 to the target distance. Note that in the hand 10 shown in Figures 2 and 4, the piston rods 82b and 83b are in the second position.

[0098] Next, in step S106, the belt control unit 210 operates the motor 51 of the first drive unit 5 to advance the first retainer 4 and the second retainer 6 to the first position. As a result, the suction pad 41 of the first retainer 4 and the suction pad 61 of the second retainer 6 protrude forward from the front end of the base plate 31. In addition, the arm control unit 26 brings the first retainer 4 and the second retainer 6 into contact with the two selected articles W from the side. Specifically, the arm control unit 26 operates the robot arm 11 so that the base plate 31 is at approximately the same height as or lower than the bottom of the lower of the two articles W. At that height, the arm control unit 26 brings the suction pads 41 and 61 into contact with the corresponding articles W from the side. At this time, the suction control unit 211 operates the negative pressure generator 17 and connects the negative pressure generator 17 with the first retainer 4 and the second retainer 6. As a result, the first retainer 4 and the second retainer 6 begin to attract. In this way, the first retainer 4 and the second retainer 6 become attracted to the two articles W.

[0099] Subsequently, in step S107, the belt control unit 210 operates the motor 51 of the first drive unit 5 to retract the first retainer 4 and the second retainer 6 to the second position. As a result, the articles W held in the first retainer 4 and the second retainer 6 are pulled toward the base plate 31 in the first direction X. The articles W pulled toward the first direction X, specifically the lower of two stacked articles W, are placed on the conveying surface 52a of the transmission belt 52. By being placed on the conveying surface 52a, the articles W are also conveyed by the transmission belt 52 via the frictional force of the conveying surface 52a. In other words, the articles W are pulled toward the first direction X by the first retainer 4, the second retainer 6 and the transmission belt 52. Furthermore, when the articles W are placed on the conveying surface 52a, they are also placed on the mounting surface 31d of the base plate 31. The mounting surface 31d has a low coefficient of friction and functions as a sliding surface. In other words, the article W is supported by the load on the base plate 31 and pulled in the first direction X by the first retainer 4, the second retainer 6 and the transmission belt 52. The article W is pulled towards the base plate 31 until the first retainer 4 and the second retainer 6 reach the second position. In this way, the article W is placed on the base plate 31.

[0100] Furthermore, the suction of the article W by the first retainer 4 and the second retainer 6 may be released at any time after the article W has been pulled into the base plate 31.

[0101] Next, in step S108, the item W is unloaded. The arm control unit 26 operates the robot arm 11 to move the hand 10 to the target position of the item W. At this time, the travel control unit 25 may move the transport vehicle 15 if necessary. When the hand 10 reaches the target position, the belt control unit 210 operates the motor 51 of the first drive unit 5 to move the first holder 4 and the second holder 6 forward. The item W is pressed forward by the first holder 4 and the second holder 6 and pulled forward by the transport surface 52a of the transmission belt 52. Finally, the item W is placed in the target position. This completes the transfer of the two items W.

[0102] Once the transfer of the two items W is complete, the process from step S101 onwards is repeated. The process from step S101 onwards is repeated until all items W at the starting position are gone. Depending on the size and arrangement of the items W, the hand 10 may hold and transport only one item W at a time. For example, if the item W is large, or if the hand 10 is holding the last item W in the vertical direction, the hand 10 may hold one item W using both the first holder 4 and the second holder 6, or using only the first holder 4.

[0103] Furthermore, when holding one or two items W placed directly on the floor, in step S106, the arm control unit 26 operates the robot arm 11 to bring the base plate 31 as close to the floor as possible. When the items W are placed directly on the floor, the base plate 31 cannot be positioned at approximately the same height as or lower than the bottom of the items W. However, in the hand 10, the motor 51 is positioned so as not to protrude from the bottom surface 31b of the base plate 31, so the base plate 31 can be brought as close to the floor as possible. This makes it easier to pull the items W held by the first holder 4 onto the base plate 31.

[0104] Furthermore, when holding one or two articles W placed directly on the floor, before pulling the articles W onto the base plate 31 in step S107, the lifting control unit 29 activates the lifting device 9 to move the first holder 4 and the second holder 6 upward in the second direction Z. This pulls the articles W held by the first holder 4 upward. In this state, the belt control unit 210 activates the motor 51 of the first drive device 5 to retract the first holder 4 and the second holder 6 to the second position. At an appropriate timing when a portion of the articles W has reached above the base plate 31, the lifting control unit 29 activates the lifting device 9 to move the first holder 4 downward in the second direction Z. This places the articles W held by the first holder 4 onto the mounting surface 31d of the base plate 31 and the conveying surface 52a of the transmission belt 52. Subsequently, the article W is pulled toward the base plate 31 until the first retainer 4 and the second retainer 6 reach the second position. In this way, the article W is placed on the base plate 31. Steps S108 onward are the same as those described above.

[0105] By using the hand 10 in the transfer of such items W, the transport efficiency of the items W can be improved. Specifically, the hand 10 is equipped with a first holder 4 and a second holder 6, and the distance from the first holder 4 to the second holder 6 in the second direction Z, that is, the spacing between the first holder 4 and the second holder 6 in the second direction Z, can be adjusted. By appropriately adjusting the distance from the first holder 4 to the second holder 6, the hand 10 can appropriately hold two items W at once. As a result, the transport efficiency of the items W is improved compared to when the items W are transported one by one by the hand 10.

[0106] Furthermore, the size of two items W that can be held at once depends on the distance from the first holder 4 to the second holder 6. By adjusting the distance from the first holder 4 to the second holder 6, the range of sizes of two items W that can be held at once can be expanded. Even when holding a single item W with the hand 10, the range of items W that can be held can be expanded by adjusting the distance from the first holder 4 to the second holder 6. In other words, the limit of the size of an item W that can be held by the hand 10 depends on the distance from the first holder 4 to the second holder 6. By increasing the distance from the first holder 4 to the second holder 6, it becomes possible to hold a larger item W. In addition, in order to properly hold an item W, the position at which it is held in relation to the center of gravity of the item W is also important. By adjusting the distance from the first holder 4 to the second holder 6, it is possible to grip the item W at an appropriate position in relation to its center of gravity. In other words, the range of items W that can be properly held can also be expanded in relation to the center of gravity of the item W. In this way, the range of items W that can be held is expanded, regardless of the number of items W, thereby improving the transport capacity of the hand 10.

[0107] As the scope of application for the article W is expanded in this way, the weight of the article W held by the first retainer 4 and the second retainer 6 can also become heavier. Since the hand 10 has two transmission belts 52, the force used to pull in the article W is increased by the transmission belts 52. As a result, even heavier articles W can be properly pulled towards the base 3 by the first retainer 4, the second retainer 6 and the transmission belts 52.

[0108] Furthermore, by achieving the movement of the second retainer 6 in the second direction Z using a combination of the variable drive unit 81 and the first fixed drive unit 82, the amount of movement of the second retainer 6 can be adjusted within a range larger than that adjustable by the variable drive unit 81.

[0109] As described above, the hand 10 comprises a base 3, a first holder 4 supported so as to be movable in a predetermined first direction X relative to the base 3 and holding an article W, a first drive device 5 for moving the first holder 4 in the first direction X, and a second holder 6 positioned alongside the first holder 4 in a second direction Z intersecting the first direction X, supported so as to be movable in the first direction X relative to the base 3 and holding an article W. The article W held by the first holder 4 and the second holder 6 is placed on the base 3, and the second holder 6 is configured to be able to adjust its distance from the first holder 4 in the second direction Z.

[0110] With this configuration, the range of items W that can be held by the hand 10 can be expanded by adjusting the distance between the second holder 6 and the first holder 4 in the second direction Z. For example, two parallel items W can be held by the first holder 4 and the second holder 6, respectively. In this case, by adjusting the distance between the second holder 6 and the first holder 4 in the second direction Z to match the size of each of the two items W, items W of various sizes can be held appropriately. Even when holding a single item W with the first holder 4 and the second holder 6, items W of various sizes can be held appropriately by adjusting the distance between the second holder 6 and the first holder 4 in the second direction Z. As a result, the range of items W that can be held can be expanded, and the transport capacity of the hand 10 can be improved.

[0111] Specifically, the hand 10 further includes a guide 7 that supports the second retainer 6 so that it can move in the second direction Z, and a second drive device 8 that moves the second retainer 6 in the second direction Z.

[0112] In this configuration, the second retainer 6 is guided in the second direction Z by the guide 7 and driven in the second direction Z by the second drive unit 8. This adjusts the distance of the second retainer 6 to the first retainer 4 in the second direction Z.

[0113] Furthermore, the guide 7 includes a first movable body 71, a first guide 74 that supports the first movable body 71 so that it can move in a second direction Z relative to the base 3, a second movable body 72 to which a second retainer 6 is provided, and a second guide 75 that supports the second movable body 72 so that it can move in a second direction Z relative to the first movable body 71. The second drive unit 8 includes a variable drive unit 81 that can adjust the amount of movement of the second retainer 6 and a first fixed drive unit 82 that moves the second retainer 6 by a constant amount of movement. One of the variable drive unit 81 and the first fixed drive unit 82 drives the first movable body 71, and the other of the variable drive unit 81 and the first fixed drive unit 82 drives the second movable body 72.

[0114] In this configuration, the movement of the second retainer 6 in the second direction Z is achieved by a two-stage movement involving the movement of the first movable body 71 and the movement of the second movable body 72. One of the variable drive unit 81 and the first fixed drive unit 82 drives the first movable body 71, while the other of the variable drive unit 81 and the first fixed drive unit 82 drives the second movable body 72. Therefore, the position of the second retainer 6 in the second direction Z can be adjusted not only within the adjustable range of the variable drive unit 81, but also within the adjustable range of the variable drive unit 81 in addition to a fixed amount of movement by the first fixed drive unit 82. In other words, by realizing part of the movement of the second retainer 6 with the first fixed drive unit 82, the configuration of the second drive unit 8 is simplified, while the range in which the position of the second retainer 6 can be arbitrarily adjusted can be expanded by combining the variable drive unit 81 and the first fixed drive unit 82.

[0115] Furthermore, the second direction Z is the vertical direction, the second moving body 72 is positioned above the first moving body 71, the variable drive unit 81 drives the first moving body 71, and the first fixed drive unit 82 drives the second moving body 72.

[0116] This configuration allows the variable drive unit 81 to be positioned relatively low. The variable drive unit 81 has a more complex structure than the first fixed drive unit 82, and therefore tends to be heavier than the first fixed drive unit 82. By positioning the relatively heavy variable drive unit 81 lower, the center of gravity of the hand 10 can be lowered.

[0117] Specifically, the variable drive unit 81 is an electric cylinder, and the first fixed drive unit 82 is an air cylinder.

[0118] Generally, electric cylinders tend to be heavier than air cylinders. By forming the variable drive unit 81 with an electric cylinder and driving the first movable body 71 with the variable drive unit 81, the relatively heavy electric cylinder can be positioned relatively low. This makes it possible to lower the center of gravity of the hand 10.

[0119] Furthermore, the first drive unit 5 includes a motor 51 and a transmission belt 52 that transmits the driving force of the motor 51, and the first retainer 4 is connected to the transmission belt 52.

[0120] In this configuration, the first retainer 4 is driven in the first direction X by the motor 51 via the transmission belt 52.

[0121] Furthermore, the transmission belt 52 has a conveying surface 52a on which the article W held by the first holder 4 is placed, and moves the conveying surface 52a together with the first holder 4.

[0122] In this configuration, the transmission belt 52 moves both the first holder 4 and the conveying surface 52a in the first direction X. Therefore, by placing the article W held by the first holder 4 on the conveying surface 52a of the transmission belt 52, the article W is moved in the first direction X not only by the first holder 4 but also by the transmission belt 52 via the frictional force between it and the conveying surface 52a.

[0123] In addition, the first drive unit 5 has at least two transmission belts 52.

[0124] With this configuration, the article W held by the first retainer 4 is placed on the conveying surfaces 52a of at least two transmission belts 52, thereby increasing the frictional force with the transmission belts 52. In other words, the conveying capacity of the article W by the transmission belts 52 can be improved.

[0125] Furthermore, the base 3 includes a base plate 31 having a mounting surface 31d on which the article W held by the first retainer 4 is placed, and a bottom surface 31b opposite to the mounting surface 31d. The transmission belt 52 is positioned on the base plate 31 so as to extend along the base plate 31, and the motor 51 is positioned on the base 3 so as not to protrude from the bottom surface 31b.

[0126] In this configuration, the transmission belt 52 is positioned along the base plate 31, so the motor 51 is also positioned near the base plate 31. However, the motor 51 is positioned so as not to protrude from the bottom surface 31b of the base plate 31. Therefore, when holding an item W placed directly on the floor or the like, the base plate 31 can be brought as close as possible to the surface on which the item W is placed. As a result, it becomes easier to pull the item W held by the first holder 4 onto the base plate 31.

[0127] Furthermore, the piping or wiring to the first retainer 4 and the second retainer 6, i.e., the housing duct 35, is positioned on the base 3 in such a way that it does not protrude from the bottom surface 31b.

[0128] With this configuration, the amount of object protruding from the bottom surface 31b of the base plate 31 is reduced, allowing the base plate 31 to be brought as close as possible to the surface on which the item W is placed. As a result, it becomes easier to pull the item W, which is placed directly on the floor or the like, onto the base plate 31.

[0129] Furthermore, no other objects protrude from the bottom surface 31b of the base plate 31.

[0130] With this configuration, since no other objects protrude from the bottom surface 31b, the base plate 31 can be brought as close as possible to the surface on which the item W is placed. As a result, it becomes easier to pull the item W, which is placed directly on the floor or the like, onto the base plate 31.

[0131] Other embodiments As described above, the embodiments described herein have been presented as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited thereto and can be applied to embodiments that have been modified, replaced, added, or omitted as appropriate. Furthermore, it is possible to combine the components described in the embodiments above to create new embodiments. In addition, the components described in the attached drawings and detailed description may include not only components essential for solving the problem, but also components that are not essential for solving the problem, in order to illustrate the technology. Therefore, the mere presence of such non-essential components in the attached drawings and detailed description should not be immediately assumed to mean that those non-essential components are essential.

[0132] Robot 1 does not necessarily have to have a transport vehicle 15 and an equipment housing 16. For example, robot 1 may be fixed in place. The hand 10 is not limited to application to robot 1, but may also be applied to automated machines that perform specific actions.

[0133] The holding of the article W by the hand 10 is not limited to suction. For example, the first retainer 4 and the second retainer 6 may have multiple fingers that perform opening and closing operations. That is, the first retainer 4 and the second retainer 6 may be grippers.

[0134] Furthermore, the type of holding mechanism of the first retainer 4 and the type of holding mechanism of the second retainer 6 may be different. For example, the first retainer 4 may be a suction pad and the second retainer 6 may be a gripper.

[0135] The first retainer 4 and the second retainer 6 move together in the first direction X by the first drive unit 5, but are not limited to this. In other words, the first retainer 4 and the second retainer 6 may be configured to move in the first direction X by independent drive units.

[0136] The device that drives the first retainer 4 and the second retainer 6 in the first direction X, i.e., the first drive device 5, is not limited to a belt drive. For example, the first drive device 5 may be configured by a lead screw mechanism. That is, the carriage 56 may be moved in the first direction X by a lead screw.

[0137] The number of transmission belts 52 in the first drive unit 5 is not limited to two. The number of transmission belts 52 may be one or three or more.

[0138] The configuration for moving the second retainer 6 in the second direction Z is not limited to the guide 7 and the second drive unit 8. For example, the guide 7 may consist only of the first moving body 71 and the first guide 74, the second retainer 6 may be attached to the first moving body 71, and the second drive unit 8 may consist only of a variable drive unit 81 that moves the first moving body 71 in the second direction Z. The variable drive unit 81 is not limited to an electric cylinder having a ball screw mechanism. The variable drive unit 81 may be a rack and pinion or a belt drive mechanism.

[0139] Furthermore, the second drive unit 8 may adjust the amount of movement of the second retainer 6 in the second direction Z not continuously, but in steps, i.e., discretely. Alternatively, the second drive unit 8 may selectively switch the position of the second retainer 6 in the second direction Z between the first position and the second position, i.e., the amount of movement of the second retainer 6 may not be adjustable. The second drive unit 8 is not limited to an electric cylinder or an air cylinder. The second drive unit 8 may be a lead screw mechanism, a link mechanism, a belt drive mechanism, etc.

[0140] The second direction Z, which is the direction of movement of the second retainer 6, is not limited to a direction substantially perpendicular to the base plate 31, i.e., the vertical direction. The second direction Z may also be a direction substantially parallel to the base plate 31, i.e., the horizontal direction. With this configuration, the hand 10 can hold two articles W placed side by side together with the first retainer 4 and the second retainer 6. Even in this case, by adjusting the horizontal distance between the first retainer 4 and the second retainer 6, the articles W can be appropriately held to accommodate articles W of various sizes or weight balances.

[0141] The hand 10 may include one or more additional retainers in addition to the first retainer 4 and the second retainer 6. The additional retainers may or may not be adjustable in distance from the first retainer 4 in the second direction Z. In view of a configuration with multiple drive belts 52 or a configuration where nothing protrudes from the bottom surface 31b of the base plate 31, the hand may include only the first retainer 4 and not the second retainer 6.

[0142] The hand 10 does not necessarily have to be equipped with an imaging device 19. For example, if the arrangement of the multiple items W before holding is known, the imaging device 19 is unnecessary. Alternatively, an imaging device separate from the robot 1 may be provided.

[0143] Article W is not limited to cardboard boxes. Article W is not limited to boxes and may be a burlap sack or the like for storing grains, etc. In that case, the first retainer 4 and the second retainer 6 are preferably grippers rather than suction pads.

[0144] The flowchart in Figure 9 is merely an example. The steps in the flowchart may be changed, replaced, added, or omitted as appropriate. Furthermore, the order of the steps in the flowchart may be changed, or sequential processes may be processed in parallel.

[0145] The functions realized by the components described herein may be implemented in circuits or processing circuits, including general-purpose processors, application-specific processors, integrated circuits, ASICs (Application Specific Integrated Circuits), CPUs (a Central Processing Unit), conventional circuits, and / or combinations thereof, programmed to realize the functions described herein. A processor includes transistors and other circuits and is considered a circuit or processing circuit. A processor may be a programmable processor that executes a program stored in memory.

[0146] In this specification, circuits, units, and means are hardware programmed to perform or execute the functions described herein. Such hardware may be any hardware disclosed herein, or any hardware known to be programmed to perform or execute the functions described herein.

[0147] If the hardware is a processor that is considered to be a type of circuit, then the circuit, means, or unit is a combination of hardware and software used to constitute the hardware and / or processor. [Explanation of symbols]

[0148] 10 hands 3 base 31 Base Plate 31b Bottom 31d Mounting surface 35. Containing ducts (piping or wiring) 4 1st retainer 5. First drive unit 51 Motor 52 Transmission belt 52a Conveying surface 6 Second retainer 7 Guide 71 First Mobile Unit 72 Second Mobile Unit 74 Guide 1 75 Guide 2 8. Second drive unit 81 Variable drive unit 82 First fixed drive unit X 1st direction Z 2nd direction W Goods

Claims

1. Bass and, A first holder that is supported so as to be movable in a predetermined first direction relative to the base and holds an article, A first drive device for moving the first retainer in the first direction, The apparatus comprises a second retainer positioned alongside the first retainer in a second direction intersecting the first direction, supported so as to be movable in the first direction relative to the base, and for holding an article, The base is on which the articles held by the first holder and the second holder are placed. The first drive device moves the first retainer in a first direction relative to the base without moving the base. The second retainer is configured to allow adjustment of its distance from the first retainer in the second direction.

2. In the hand described in claim 1, A guide that supports the second retainer so as to be movable in the second direction, A hand further comprising a second drive device for moving the second retainer in the second direction.

3. A base and, A first holder that is supported so as to be movable in a predetermined first direction relative to the base and holds an article, A first drive device for moving the first retainer in the first direction, A second retainer is positioned alongside the first retainer in a second direction intersecting the first direction, is supported so as to be movable in the first direction relative to the base, and holds an article; A guide that supports the second retainer so as to be movable in the second direction, The system comprises a second drive device for moving the second retainer in the second direction, The base is on which the articles held by the first holder and the second holder are placed. The second retainer is configured to be adjustable in distance from the first retainer in the second direction. The guide comprises a first movable body, a first guide that supports the first movable body so as to be movable in the second direction relative to the base, a second movable body provided with the second retainer, and a second guide that supports the second movable body so as to be movable in the second direction relative to the first movable body. The second drive device includes a variable drive device that can adjust the amount of movement of the second retainer and a fixed drive device that moves the second retainer by a constant amount of movement. One of the variable drive device and the fixed drive device drives the first moving body, The other of the variable drive device and the fixed drive device is a hand that drives the second moving body.

4. In the hand described in claim 3, The second direction is the vertical direction. The second moving body is positioned above the first moving body. The variable drive device drives the first moving body, The aforementioned fixed drive device is a hand that drives the second moving body.

5. In the hand according to claim 3 or 4, The variable drive device is an electric cylinder, The aforementioned fixed drive device is a hand which is an air cylinder.

6. A base and, A first holder that is supported so as to be movable in a predetermined first direction relative to the base and holds an article, A first drive device for moving the first retainer in the first direction, The apparatus comprises a second retainer positioned alongside the first retainer in a second direction intersecting the first direction, supported so as to be movable in the first direction relative to the base, and for holding an article, The base is on which the articles held by the first holder and the second holder are placed. The second retainer is configured to be adjustable in distance from the first retainer in the second direction. The first drive device comprises a motor and a transmission belt that transmits the driving force of the motor. The first retainer is a hand connected to the transmission belt.

7. In the hand described in claim 6, The transmission belt has a conveying surface on which an article held by the first holder is placed, and a hand moves the conveying surface together with the first holder.

8. In the hand described in claim 7, The first drive device is a hand having at least two of the transmission belts.

9. In the hand according to any one of claims 6 to 8, The base includes a base plate having a mounting surface on which the article held by the first holder is placed, and a bottom surface opposite to the mounting surface. The transmission belt is positioned on the base plate so as to extend along the base plate. The motor is positioned on the base in a manner that it does not protrude from the bottom surface.

10. In the hand according to claim 9, The piping or wiring to the first and second retainers is positioned on the base in such a manner that it does not protrude from the bottom surface.

11. In the hand according to claim 9 or 10, The base plate is a handle in which no other object protrudes from the bottom surface.

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