Hand

Abstract

To improve a carrying capability of a hand which carries an article while making a retainer place the article on a base.SOLUTION: A hand 100 is provided with: a base 3; a first retainer 4 that is supported to be movable in a predetermined first direction X with respect to the base 3 to retain an article W; a second retainer 6, arranged in parallel with the first retainer 4 in a second direction Z crossing the first direction X, which is supported to be movable in the first direction X with respect to the base 3 to retain the article W; a first driving device 5 that moves the first retainer 4 and the second retainer 6 in the first direction X; and an adjusting device 9 that adjusts a position in the first direction X of either of the first retainer 4 and the second retainer 6 independently from the other of the first retainer 4 and the second retainer 6.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Hands equipped with a holder for holding an object have been known for some time. For example, Patent Document 1 discloses a hand having a holder for holding an object and a base on which the object is placed. This hand moves the holder holding the object in a predetermined direction and places the object on the base. The hand transports the object while it is placed on the base. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021 / 025019 Summary of the Invention [Problem to be solved by the invention]

[0004] The hand described above is configured to be able to hold articles of various sizes by enlarging the holder, but there is still room for improvement in the hand's transport capability, and the hand described above is still in need of further improvement.

[0005] The technology disclosed herein has been developed in consideration of these points, and its purpose is to improve the transport capacity of a hand that transports an item by placing it on a base using a holder. [Means for solving the problem]

[0006] The hand disclosed herein comprises a base, a first holder supported so as to be movable in a predetermined first direction relative to the base and holding an article, a second holder arranged alongside the first holder in a second direction intersecting the first direction and supported so as to be movable in the first direction relative to the base and holding an article, a first drive device that moves the first holder and the second holder in the first direction, and an adjustment device that adjusts the position of one of the first holder and the second holder in the first direction independently of the other of the first holder and the second holder. [Effects of the Invention]

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

[0008] [Figure 1] FIG. 1 is a diagram showing the configuration of a robot system. [Figure 2] FIG. 2 is a front view of the hand with the second holder raised. [Figure 3] FIG. 3 is a side view of the hand in a state in which the first holder and the second holder are advanced and the second holder 6 is raised. [Figure 4] FIG. 4 is a plan view of the hand in a state where the first holder and the second holder are retracted. [Figure 5] FIG. 5 is a rear view of the hand with the second holder raised. [Figure 6] FIG. 6 is a front view of the hand with the second holder lowered. [Figure 7] FIG. 7 is a side view of the hand in a state where the first holder and the second holder are advanced in the first direction by the adjustment device. [Figure 8] FIG. 8 is a diagram illustrating a schematic hardware configuration of the control device. [Figure 9] FIG. 9 is a functional block diagram of the processor. [Figure 10] FIG. 10 is a flow chart of the transfer of goods. DETAILED DESCRIPTION OF THE INVENTION

[0009] 1 is a diagram showing a configuration of a robot system S. In the following, exemplary embodiments will be described in detail with reference to the accompanying drawings.

[0010] The robot system S is a system for transporting an item. Here, a case will be described in which an item W stacked at a predetermined location is transported to a destination location. The item W is, for example, a cardboard box. The robot system S includes a robot 1 that transports the item W and a control device 2 that controls the robot 1.

[0011] The robot 1 is, for example, an industrial robot. The robot 1 has a robot arm 110 and a hand 100 connected to the robot arm 110. In this example, the robot 1 further has a transport vehicle 15 and an equipment housing section 16. The robot arm 110 is mounted on the transport vehicle 15. The equipment housing section 16 houses equipment necessary for controlling the robot 1, including a control device 2. The robot 1 moves autonomously by the transport vehicle 15.

[0012] The robot arm 110 changes the position and posture of the hand 100. The robot arm 110 is a vertical multi-joint robot arm. The robot arm 110 has a plurality of links L, joints J connecting the plurality of links L, and a servo motor 14 (see FIG. 8) that rotationally drives the plurality of joints J. For example, the link L located at one end of the robot arm 110 is connected to the transport vehicle 15 via the joint J so as to be rotatable around a rotation axis extending in the vertical direction. The robot arm 110 may be a horizontal multi-joint robot arm, a parallel link robot arm, a Cartesian coordinate robot arm, a polar coordinate robot arm, or the like.

[0013] The hand 100 is an end effector of the robot arm 110. The hand 100 is connected to the tip of the robot arm 110. Specifically, the hand 100 is connected to the link L at the end opposite to the link L connected to the transport vehicle 15, among the multiple links L. The hand 100 can take various postures depending on the operation of the robot arm 110.

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

[0015] The equipment housing section 16 houses a negative pressure generator 17 and an air supply device 18 in addition to the control device 2. The negative pressure generator 17 generates negative pressure in the suction pads 41 and 61, which will be described later. For example, the negative pressure generator 17 is a vacuum pump or an ejector. If the negative pressure generator 17 is small, for example, if the vacuum generator 17 is an ejector, the vacuum generator 17 may be mounted on the hand 100. The air supply device 18 pumps air. The air supply device 18 supplies air to the fixed drive device 82 and the adjustment device 9, which will be described later. For example, the air supply device 18 is an air pump. The air supply device 18 may be arranged outside the transport vehicle 15. The negative pressure generator 17 and the air supply device 18 are controlled by the control device 2.

[0016] Next, the configuration of the hand 100 will be described in detail. Fig. 2 is a front view of the hand 100 in a state where the second holder 6 is raised. Fig. 3 is a side view of the hand 100 in a state where the first holder 4 and the second holder 6 are advanced and the second holder 6 is raised. Fig. 4 is a plan view of the hand 100 in a state where the first holder 4 and the second holder 6 are retracted. Fig. 5 is a rear view of the hand 100 in a state where the second holder 6 is raised. Note that the rear portion of the hand 100 is cut away in Fig. 5. Therefore, the motor 51 of the first drive device 5 and the like are not shown in Fig. 5.

[0017] The hand 100 includes a base 3, a first holder 4 that holds an article W, a first driving device 5, a second holder 6 that holds the article, and an adjustment device 9. The first holder 4 is supported on the base 3 so as to be movable in a predetermined first direction X. The second holder 6 is arranged alongside the first holder 4 in a predetermined second direction Z and is supported on the base 3 so as to be movable in the first direction X. The first driving device 5 moves the first holder 4 and the second holder 6 in the first direction X. The article W held by the first holder 4 and the second holder 6 is placed on the base 3. The hand 100 holds the article W with 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 first direction X while holding the article W.

[0018] The adjustment device 9 adjusts the position of one of the first holder 4 and the second holder 6 in the first direction X independently of the other of the first holder 4 and the second holder 6. That is, at least one of the first holder 4 and the second holder 6 is moved in the first direction X by the adjustment device 9 in addition to being moved in the first direction X by the first drive device 5. This adjusts the relative positions of the first holder 4 and the second holder 6 in the first direction X, making it possible to hold articles W in various situations and with various shapes.

[0019] The second holder 6 is configured so that its position in the second direction Z is adjustable. That is, the second holder 6 is configured so that the distance between it and the first holder 4 in the second direction Z is adjustable. The hand 100 may further include a guide 7 that supports the second holder 6 movably in the second direction Z, and a second drive device 8 that moves the second holder 6 in the second direction Z. That is, the second holder 6 is moved in the second direction Z by the second drive device 8 while being guided in the second direction Z by the guide 7. This adjusts the relative positions of the first holder 4 and the second holder 6 in the second direction Z.

[0020] In this example, the second direction Z is approximately perpendicular to the first direction X. Specifically, the second direction Z is the up-down direction. Furthermore, a direction approximately perpendicular to both the first direction X and the second direction Z is defined as the third direction Y. Here, the first direction X, the second direction Z, and the third direction Y each refer to a direction that does not matter in which direction it is oriented.

[0021] More specifically, as shown in FIG. 4 , the base 3 has a base plate 31 on which the article W held by the first holder 4 is placed. In a plan view, the base plate 31 has a substantially rectangular outer shape with the first direction X as its longitudinal direction and the third direction Y as its lateral direction. The thickness direction of the base plate 31 coincides with the second direction Z. The base plate 31 has two sliding plates 31c provided on both ends of the upper surface 31a of the base plate 31 in the third direction Y and extending in the first direction X. The sliding plate 31c has a mounting surface 31d on which the article W held by the first holder 4 or the second holder 6 is placed. The mounting surface 31d faces in the second direction Z, specifically upward. The mounting surface 31d has a relatively small coefficient of friction and functions as a sliding surface along which the article W slides.

[0022] 3, an attachment 32 to which the tip of the robot arm 110 is attached is provided at one end of the base plate 31 in the first direction X. A link L at the tip of the robot arm 110 is attached to the attachment 32. By moving the robot arm 110, the hand 100 can take any posture.

[0023] For ease of explanation, the configuration of the hand 100 will be described in a position where the thickness direction of the base plate 31, i.e., the second direction Z, faces the up-down direction. This position is the position in which the hand 100 is normally used, and is referred to as the basic position. In addition, in the first direction X, the side toward the attachment 32 is the rear, and the side opposite the attachment 32 is the front. In other words, in the first direction X, the side away from the robot arm 110 is the front, and the side approaching the robot arm 110 is the rear.

[0024] As shown in Fig. 4, two rails 33 extending in the first direction X are provided on the upper surface 31a of the base plate 31. As shown in Fig. 2, a block 34 is attached to each rail 33 so as to be movable in the first direction X. In other words, the rails 33 and the blocks 34 form a linear guide that is slidable in the first direction X.

[0025] The first driving device 5 has a motor 51 and a transmission belt 52 that transmits the driving force of the motor 51. More specifically, the first driving device 5 has two transmission belts 52.

[0026] The motor 51 is an electric motor that can rotate forward and backward. As shown in FIG. 3, the motor 51 is attached to the base plate 31. More specifically, the motor 51 is disposed at the rear end of the base plate 31 in the first direction X. The motor 51 is disposed on the base 3 in a state where it does not protrude from the bottom surface 31b of the base plate 31.

[0027] As shown in FIG. 4, each transmission belt 52 is wound around a drive roller 53 and a driven roller 54 provided on the base plate 31. The drive roller 53 is also shown in FIG. 3. Each pair of drive rollers 53 and driven rollers 54 are arranged side by side in the first direction X on the base plate 31. The drive roller 53 is arranged at the rear end of the base plate 31 in the first direction X, and the driven roller 54 is arranged at the front end of the base plate 31 in the first direction X. The shaft centers of the drive roller 53 and the driven roller 54 extend in the 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 shaft centers. Specifically, the drive roller 53 and the driven roller 54 are each arranged in a through hole formed through the base plate 31 in the thickness direction.

[0028] The driving force of the motor 51 is transmitted to the driving roller 53 via a reduction gear such as a gear train. The motor 51 is common to the two driving rollers 53.

[0029] The transmission belt 52 extends in the first direction X along the upper surface 31a of the base plate 31, is wound around the drive roller 53, and passes through the through hole to rotate toward the bottom surface 31b of the base plate 31, extends in the first direction X along the bottom surface 31b, is wound around the driven roller 54, and passes through the through hole to rotate toward the upper surface 31a of the base plate 31. As a result, the transmission belt 52 is disposed on the base plate 31 so as to extend along the base plate 31. The two transmission belts 52 are disposed side by side in the third direction Y. The transmission belts 52 may be either an ended belt or an endless belt.

[0030] The first holder 4 is connected to the transmission belt 52. More specifically, a carriage 56 is fixed to the transmission belt 52. The carriage 56 is fixed to a portion of the transmission belt 52 that extends along the upper surface 31a. As shown in FIG. 5 , the carriage 56 is also fixed to the block 34. That is, 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 is immovable in the second direction Z and the third direction Y. The carriage 56 supports the first holder 4.

[0031] 3, the first holder 4 has a plurality of suction pads 41 and a back plate 42 that supports the suction pads 41. The first holder 4 is supported by a base frame 43.

[0032] The back plate 42 is a substantially rectangular plate. The thickness direction of the back plate 42 faces 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 a surface of the back plate 42 facing forward. As shown in FIG. 2, the plurality of 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, which causes an object approaching or coming into contact with the opening of the suction pad 41 to be sucked in. Multiple suction pads 41 can be connected to the negative pressure generator 17 via a common piping system or 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] As shown in Fig. 5, the base frame 43 has a bottom plate 43a and a pair of support plates 43b provided on the bottom plate 43a. Note that Fig. 5 shows only one of the support plates 43b. The bottom plate 43a extends in the third direction Y with its thickness direction facing the second direction Z. A pair of support plates 43b are disposed on both ends of the bottom plate 43a in the third direction Y. The pair of support plates 43b extend in the second direction Z with their thickness direction facing the third direction Y.

[0036] The carriage 56 supports the first holder 4 configured in this manner so as to be movable in the second direction Z and so as to be immovable in the first direction X and the third direction Y.

[0037] In detail, as shown in FIG. 5, the carriage 56 has a bottom plate 56a, a pair of support plates 56b provided on the bottom plate 56a, a pair of rails 56c fixed to the pair of support plates 56b, and a pair of blocks 56d slidably connected to the pair of rails 56c in the second direction Z.

[0038] The bottom plate 56a extends in the third direction Y with its thickness direction facing the second direction Z. A pair of support plates 56b is arranged at both ends of the bottom plate 56a in the third direction Y. The bottom plate 56a is arranged below the bottom plate 43a of the base frame 43. The pair of support plates 56b are arranged side by side in the third direction Y with a gap between them with their thickness direction facing the third direction Y. Each support plate 56b extends in the second direction Z, i.e., in the up-down direction. The pair of support plates 56b are arranged outside the pair of support plates 43b of the base frame 43 in the third direction Y.

[0039] A corresponding rail 56c is fixed to each support plate 56b. The rail 56c extends in the second direction Z. The rail 56c and the block 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 arranged inside the pair of support plates 56b and outside the pair of support plates 43b of the base frame 43 in the third direction Y.

[0040] The pair of blocks 56d are fixed to the pair of support plates 43b. Therefore, the pair of support plates 43b, i.e., the base frame 43, is movable in the second direction Z along the rails 56c. Since the base frame 43 supports the first holder 4, the first holder 4 is also movable in the second direction Z.

[0041] As shown in FIG. 5 , the base frame 43 and the carriage 56 are provided with elevating devices 57 that move the first holder 4 in the second direction Z, i.e., the up-and-down direction. More specifically, the base frame 43 and the carriage 56 are provided with two elevating devices 57 that are aligned in the third direction Y. The elevating devices 57 are air cylinders. The elevating devices 57 have a piston rod 57a. The piston rod 57a extends in the second direction Z. The elevating devices 57 move the piston rod 57a in the second direction Z. The elevating devices 57 are fixed to the bottom plate 43a of the base frame 43. The piston rod 57a extends downward from the bottom plate 43a and is fixed to the bottom plate 56a of the carriage 56.

[0042] The lifting device 57 is connected to the air supply device 18 via an air tube. The air tube is provided with a solenoid valve that switches the air supply state to the lifting device 57. By switching the air supply state, the lifting device 57 selectively moves the piston rod 57a between a first position where the piston rod 57a is retracted and a second position where the piston rod 57a is advanced. The first position is the position where the base frame 43 is closest to the bottom plate 56a, and the position of the first holder 4 at this time is the lowest position in the second direction Z. The second position is the position where the base frame 43 is farthest from the bottom plate 56a, and the position of the first holder 4 at this time is the highest position in the second direction Z.

[0043] In this way, the first holder 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 57. As will be described in detail later, the lifting device 57 is used to assist in pulling the article W held by the first holder 4 or the second holder 6 onto the base plate 31.

[0044] 2, the second holder 6 is attached to the base frame 43 via a guide 7. The base frame 43 is supported by the carriage 56, and as a result, the second holder 6 is attached to the carriage 56. The second holder 6 has a plurality of suction pads 61 and a back plate 62 that supports the suction pads 61. The back plate 62 is arranged so that its thickness direction faces the first direction X.

[0045] 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 a surface of the back plate 62 facing forward. The plurality of suction pads 61 are arranged in a matrix on the back plate 62. The suction pad 61 has an opening facing forward.

[0046] The suction pad 61 is connected to the negative pressure generator 17 via piping. The negative pressure generator 17 generates negative pressure, which causes an object approaching or coming into contact with the opening of the suction pad 61 to be sucked in. Multiple suction pads 61 can be connected to the negative pressure generator 17 via a common piping system or 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.

[0047] The first driving device 5 moves the carriage 56 in the first direction X by moving the transmission belt 52 using the motor 51. This causes the first driving device 5 to move the first holder 4 in the first direction X. Because the second holder 6 is also attached to the carriage 56 via the guide 7, the first driving device 5 moves both the first holder 4 and the second holder 6 in the first direction X. The first driving device 5 moves the first holder 4 and the second holder 6 between a predetermined first position and a second position rearward of the first position in the first direction X. As shown in FIG. 3 , the first position is a position where the suction pad 41 of the first holder 4 and the suction pad 61 of the second holder 6 protrude forward in the first direction X beyond the front end of the base plate 31. The first position is a position where the first holder 4 and the second holder 6 perform suction of the article W. 4, the second position is a position where the suction pads 41 and 61 are retracted rearward in the first direction X from the front end of the base plate 31. The second position is a position when the article W held by the first holder 4 and the second holder 6 is placed on the base plate 31.

[0048] As shown in FIG. 4, the transmission belt 52 has a conveying surface 52a on which the article W held by the first holder 4 is placed. The conveying surface 52a is the outer peripheral surface of the transmission belt 52. Specifically, when the first holder 4 is located 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 holder 4. The outer peripheral surface of the portion of the transmission belt 52 located in front of the first holder 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 holder 4. The position of the conveying surface 52a in the second direction Z, i.e., its height in the up-down direction, is approximately the same as that of the placement surface 31d. The coefficient of friction of the conveying surface 52a is greater than that of the placement surface 31d.

[0049] 2, the guide 7 has a first moving body 71, a first guide 74 that supports the first moving body 71 so as to be movable in the second direction Z relative to the base 3, a second moving body 72 that is provided with the second holder 6, and a second guide 75 that supports the second moving body 72 so as to be movable in the second direction Z relative to the first moving body 71. The second moving body 72 supports the second holder 6. The second moving body 72 is disposed above the first moving body 71. The guide 7 is a linear guide that linearly guides the second holder 6 in the second direction Z.

[0050] The first guide 74 has a pair of blocks 74a fixed to the base frame 43 and a rail 74b connected to the blocks 74a so as to be slidable in the second direction Z.

[0051] The pair of blocks 74a are disposed inside the pair of support plates 43b of the base frame 43 in the third direction Y. The blocks 74a are fixed to the upper ends of the corresponding support plates 43b. The two rails 74b are also disposed inside the pair of support plates 43b in the third direction Y. The rails 74b extend in the second direction Z. The blocks 74a and the rails 74b form a linear guide that is slidable in the second direction Z. Here, because the blocks 74a are fixed to the support plates 43b, the rails 74b move in the second direction Z relative to the support plates 43b.

[0052] The first moving body 71 has a pair of support plates 71a and a connecting plate 71b that connects the pair of support plates 71a to each other.

[0053] The pair of support plates 71a are arranged side by side in the third direction Y at a distance from each other, with their thickness directions facing the third direction Y. The pair of support plates 71a are arranged inside the two rails 74b in the third direction Y. Each support plate 71a extends in the second direction Z, i.e., in the up-and-down direction. Each support plate 71a is fixed to the corresponding rail 74b. The connecting plate 71b is fixed to the upper end of the pair of support plates 71a. Because the pair of support plates 71a are fixed to the two rails 74b, the first movable body 71 moves integrally with the rails 74b in the second direction Z as the rails 74b move in the second direction Z.

[0054] The second guide 75 has a pair of rails 75a fixed to a pair of support plates 71a of the first movable body 71, and a pair of blocks 75b connected to the pair of rails 75a so as to be slidable in the second direction Z.

[0055] The pair of rails 75a are arranged side by side at a distance from each other in the third direction Y. The pair of rails 75a are arranged inside the pair of support plates 71a in the third direction Y. Each rail 75a extends in the second direction Z, i.e., in the up-and-down direction. Each rail 75a is fixed to the corresponding support plate 71a. The pair of blocks 75b are also arranged inside the pair of support plates 71a in the third direction Y. The rails 75a and the blocks 75b form a linear guide that is slidable in the second direction Z. Because the rails 75a are fixed to the support plate 71a, the blocks 75b move in the second direction Z relative to the support plate 71a.

[0056] 5, the second moving body 72 has a pair of support plates 72a and a connecting plate 72b that connects the pair of support plates 72a to each other. The second moving body 72 supports the second holder 6.

[0057] The pair of support plates 72a are arranged side by side in the third direction Y at a distance from each other, with their thickness directions facing the third direction Y. The pair of support plates 72a are arranged inside the pair of blocks 75b in the third direction Y. Each support plate 72a extends in the second direction Z, i.e., in the up-down direction. Each support plate 72a is fixed to the corresponding block 75b. The lower end of the support plate 72a is fixed to the block 75b. The connecting plate 72b is fixed to the upper end of the pair of support plates 72a. Because the pair of support plates 72a are fixed to the two blocks 75b, the second movable body 72 moves integrally with the block 75b in the second direction Z as the block 75b moves in the second direction Z.

[0058] Here, the connecting plate 71b of the first moving body 71 is disposed at a position offset in the first direction X with respect to the pair of supporting plates 71a so as to avoid interference with the supporting plates 72a of the second moving body 72.

[0059] As shown in Fig. 5, the second drive unit 8 has a variable drive unit 81 that can adjust the amount of movement of the second holder 6, and a fixed drive unit 82 that moves the second holder 6 a fixed amount of movement. In Fig. 5, the variable drive unit 81 and the fixed drive unit 82 are arranged overlapping each other in the depth direction of the page. The variable drive unit 81 drives the first movable body 71. The fixed drive unit 82 drives the second movable body 72.

[0060] The variable drive device 81 is a linear actuator. For example, the variable drive device 81 is an electric cylinder. Specifically, the variable drive device 81 has a motor 81a and a rod 81b. The rod 81b extends in the second direction Z. The rod 81b has a ball screw mechanism that is rotationally driven by the motor 81a. When the motor 81a is actuated, the rod 81b moves in the second direction Z. The motor 81a of the variable drive device 81 is fixed to the base frame 43. The rod 81b is fixed to the connecting plate 71b of the first movable body 71. When the motor 81a is actuated, the variable drive device 81 moves the first movable body 71 in the second direction Z.

[0061] The variable drive device 81 continuously adjusts the position of the rod 81b in the second direction Z, i.e., the amount of advancement, 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 movable body 71 in the second direction Z within an adjustable range by adjusting the amount of rotation of the motor 81a.

[0062] The fixed drive device 82 is a linear actuator. For example, the fixed drive device 82 is an air cylinder. The fixed drive device 82 has a piston rod 82a. The piston rod 82a extends in the second direction Z. The fixed drive device 82 moves the piston rod 82a in the second direction Z. The fixed drive device 82 is fixed to the connecting plate 71b of the first movable body 71. The piston rod 82a is fixed to the connecting plate 72b of the second movable body 72. With respect to the position in the first direction X, the fixed drive device 82 is disposed in front of the variable drive device 81.

[0063] The fixed drive device 82 is connected to the air supply device 18 via an air tube. The air tube is provided with a solenoid valve that switches the air supply state to the fixed drive device 82. By switching the air supply state, the 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 advanced. The fixed drive device 82 moves the second movable body 72 in the second direction Z relative to the first movable body 71 by advancing or retracting the piston rod 82a between the first position and the second position. The movement amount of the piston rod 82a is fixed. For example, the movement amount of the second movable body 72 by the fixed drive device 82 is equal to or less than the maximum movement amount of the first movable body 71 by the variable drive device 81.

[0064] The second drive device 8 moves the second holder 6 in the second direction Z by the variable drive device 81 and the fixed drive device 82. The second drive device 8 operates the variable drive device 81 and the fixed drive device 82 independently.

[0065] More specifically, the second drive unit 8 moves the first moving body 71 in the second direction Z by adjusting the amount of advancement of the rod 81b of the variable drive unit 81. The second moving body 72 is supported on the first moving body 71, and the second holder 6 is supported on the second moving body 72. Therefore, when the first moving body 71 moves in the second direction Z, the second moving body 72 and the second holder 6 move in the second direction Z together with the first moving body 71. The second drive unit 8 can arbitrarily adjust the amount of movement of the first moving body 71 in the second direction Z, and therefore the amount of movement of the second holder 6, within an adjustable range of the amount of advancement of the rod 81b.

[0066] The second drive unit 8 moves the second movable body 72 in the second direction Z by changing the amount of advancement of the piston rod 82a of the fixed drive unit 82. The second drive unit 8 selectively switches the position of the piston rod 82a of the fixed drive unit 82 between a first position and a second position. When the piston rod 82a is located at the first position, the second movable body 72 is closest to the first movable body 71 in the second direction Z. On the other hand, when the piston rod 82a is located at the second position, the second movable body 72 is farthest from the first movable body 71 in the second direction Z. When the second movable body 72 moves in the second direction Z, the second holder 6 moves in the second direction Z together with the second movable body 72. The second drive unit 8 moves the second movable body 72, and therefore the second holder 6, a fixed distance in the second direction Z by switching the position of the piston rod 82a between the first position and the second position.

[0067] FIG. 6 is a front view of the hand 100 with the second holder 6 lowered. When the amount of extension of the rod 81b of the variable drive device 81 is minimum and the piston rod 82a of the fixed drive device 82 is in the first position, the distance from the first holder 4 to the second holder 6 in the second direction Z is minimum, as shown in FIG. 6. Here, the distance from the first holder 4 to the second holder 6 in the second direction Z is defined as the distance in the second direction Z between the center of gravity of the first holder 4 in its front view and the center of gravity of the second holder 6 in its front view. When the amount of extension of the rod 81b of the variable drive device 81 is maximum and the piston rod 82a of the fixed drive device 82 is in the second position, the distance from the first holder 4 to the second holder 6 in the second direction Z is maximum, as shown in FIG. The second drive device 8 adjusts the distance from the first holder 4 to the second holder 6 in the second direction Z between the minimum distance and the maximum distance by appropriately combining adjustment of the amount of movement by the variable drive device 81 and switching of the amount of movement by the fixed drive device 82.

[0068] Here, since the amount of movement by the fixed drive device 82 is less than the maximum amount of movement by the variable drive device 81, the distance from the first holder 4 to the second holder 6 in the second direction Z can be adjusted over the entire range between the minimum distance and the maximum distance.

[0069] 7 is a side view of the hand 100 in a state in which the first holder 4 and the second holder 6 have been advanced in the first direction X by the adjustment device. In FIG. 7, the first holder 4 and the second holder 6 have been advanced in the first direction X by the first drive device 5, and the second holder 6 has been raised in the second direction Z. The adjustment device 9 includes a first adjustment device 9A that adjusts the position of the first holder 4 in the first direction X independently of the second holder 6, and a second adjustment device 9B that adjusts the position of the second holder 6 in the first direction X independently of the first holder 4.

[0070] The first adjustment device 9A includes a first drive device 91. In this example, as shown in FIG. 5, the first adjustment device 9A includes two first drive devices 91. The two first drive devices 91 are arranged side by side in the third direction Y. The first drive devices 91 are fixed to the base frame 43. The first drive devices 91 are linear actuators. For example, the first drive devices 91 are air cylinders. As shown in FIG. 7, the first drive devices 91 have a piston rod 91a. The piston rod 91a extends in the first direction X. The first drive device 91 moves the piston rod 91a in the first direction X. The piston rod 91a is fixed to the back plate 42 of the first retainer 4.

[0071] As shown in FIG. 5, the first adjustment device 9A further includes a linear guide 92 that guides the first holder 4 in the first direction X. In this example, the first adjustment device 9A includes two linear guides 92. The two linear guides 92 are arranged side by side in the third direction Y. The linear guides 92 support the first holder 4 movably in the first direction X relative to the base frame 43. The linear guide 92 includes a shaft 92a and an outer cylinder 92b. As shown in FIG. 7, the shaft 92a extends in the first direction X. The shaft 92a is slidably inserted into the outer cylinder 92b. The front end of the shaft 92a is fixed to the back plate 42 of the first holder 4. The outer cylinder 92b is fixed to the base frame 43. That is, the outer cylinder 92b supports the shaft 92a slidably in the first direction X. When the shaft 92a moves in the first direction X, the first holder 4 moves in the first direction X integrally with the shaft 92a.

[0072] When the first driving device 91 moves the first holder 4 in the first direction X, the linear guide 92 guides the first holder 4 in the first direction X. The linear guide 92 allows the first holder 4 to move stably in the first direction X.

[0073] The first drive device 91 is connected to the air supply device 18 via an air tube. The air tube is provided with a solenoid valve that switches the air supply state to the first drive device 91. By switching the air supply state, the first drive device 91 selectively moves the piston rod 91a between a first position where the piston rod 91a is retracted and a second position where the piston rod 91a is advanced. The first drive device 91 adjusts the position of the first cage 4 in the first direction X by advancing or retracting the piston rod 91a between the first position and the second position. When the piston rod 91a is located in the first position, the first cage 4 is closest to the base frame 43 in the first direction X, as shown in FIG. 3. In other words, the first cage 4 is most retracted in the first direction X. This position is the normal position of the first cage 4. When the piston rod 91a is located in the second position, the first cage 4 is most distant from the base frame 43 in the first direction X, as shown in FIG. 7. That is, the first cage 4 advances to the furthest position in the first direction X. This position is defined as the advanced position of the first cage 4.

[0074] 4, the second adjustment device 9B includes a second drive device 95. In this example, the second adjustment device 9B includes one second drive device 95. The second drive device 95 is fixed to the second moving body 72.

[0075] More specifically, a mounting frame 73 is fixed to the second movable body 72. The mounting frame 73 has a pair of side plates 73a and a front plate 73b that connects the pair of side plates 73a to each other. The pair of side plates 73a are arranged side by side in the third direction Y with a gap between them, with their thickness directions facing the third direction Y. The pair of side plates 73a are arranged at both ends in the third direction Y of the connecting plate 72b of the second movable body 72 and are fixed to the connecting plate 72b. Each side plate 73a extends in the first direction X, i.e., in the front-to-rear direction. The front plate 73b is fixed to the front ends of the pair of side plates 73a and the connecting plate 72b.

[0076] The second driving device 95 is fixed to the front plate 73b of the mounting frame 73. The second driving device 95 is disposed approximately in the center of the front plate 73b in the third direction Y. The second driving device 95 is a linear actuator. For example, the second driving device 95 is an air cylinder. The second driving device 95 has a piston rod 95a. The piston rod 95a extends through the front plate 73b in the first direction X. The second driving device 95 moves the piston rod 95a in the first direction X. The front end of the piston rod 95a is fixed to the back plate 62 of the second retainer 6.

[0077] The second adjustment device 9B further includes a linear guide 96 that guides the second holder 6 in the first direction X. In this example, the second adjustment device 9B includes two linear guides 96. The two linear guides 96 are arranged side by side in the third direction Y. The linear guides 96 support the second holder 6 movably in the first direction X relative to the second movable body 72. The linear guide 96 includes a shaft 96a and an outer cylinder 96b. The shaft 96a extends in the first direction X. The shaft 96a is slidably inserted into the outer cylinder 96b. The front end of the shaft 96a is fixed to the back plate 62 of the second holder 6. The outer cylinder 96b is fixed to the corresponding side plate 73a of the mounting frame 73. That is, the outer cylinder 96b supports the shaft 96a slidably in the first direction X. When the shaft 96a moves in the first direction X, the second retainer 6 moves in the first direction X integrally with the shaft 96a.

[0078] When the second driving device 95 moves the second holder 6 in the first direction X, the linear guide 96 guides the second holder 6 in the first direction X. The linear guide 96 allows the second holder 6 to move stably in the first direction X.

[0079] The second drive device 95 is connected to the air supply device 18 via an air tube. The air tube is provided with a solenoid valve that switches the air supply state to the second drive device 95. By switching the air supply state, the second drive device 95 selectively moves the piston rod 95a between a first position where the piston rod 95a is retracted and a second position where the piston rod 95a is advanced. The second drive device 95 adjusts the position of the second retainer 6 in the first direction X by advancing or retracting the piston rod 95a between the first and second positions. When the piston rod 95a is located in the first position, the second retainer 6 is closest to the second movable body 72 in the first direction X, as shown in FIG. 3. In other words, the second retainer 6 is most retracted in the first direction X. This position is the normal position of the second retainer 6. When the piston rod 95a is located in the second position, the second retainer 6 is most distant from the second movable body 72 in the first direction X, as shown in FIG. 7. In other words, the second retainer 6 is advanced to the maximum in the first direction X. This position is defined as the advanced position of the second retainer 6.

[0080] The maximum adjustment amount of the position of the first cage 4 in the first direction X by the first adjustment device 9A is different from the maximum adjustment amount of the position of the second cage 6 in the first direction X by the second adjustment device 9B. In this example, the maximum advancement amount of the piston rod 95a of the second drive device 95 is greater than the maximum advancement amount of the piston rod 91a of the first drive device 91.

[0081] In addition, as shown in Fig. 7, the position of the first holder 4 in the first direction X when it is moved most far in the first direction X from the base 3 by adjustment of the first adjustment device 9A is different from the position of the second holder 6 in the first direction X when it is moved most far in the first direction X from the base 3 by adjustment of the second adjustment device 9B. In other words, the position of the first holder 4 in the first direction X at the advanced position is different from the position of the second holder 6 in the advanced position. In this example, the second holder 6 at the advanced position is positioned further forward in the first direction X than the first holder 4 at the advanced position.

[0082] Furthermore, the position of the first retainer 4 in the first direction X when it is moved to the farthest position in the first direction X by adjustment of the first adjustment device 9A is substantially the same as the position of the second retainer 6 in the first direction X when it is moved to the farthest position in the first direction X by adjustment of the second adjustment device 9B, as shown in Fig. 3. In other words, the position of the first retainer 4 in the first direction X in the normal position and the position of the second retainer 6 in the first direction X in the normal position are substantially the same.

[0083] As shown in FIG. 2, the hand 100 further includes an imaging device 19. The imaging device 19 is attached to the base frame 43. The imaging device 19 is disposed 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 imaging device 19 faces generally forward in the first direction X. The imaging device 19 may be a monocular camera, a TOF (Time-of-Flight) camera, or the like.

[0084] In at least the hand 100, the piping to the first holder 4, the piping to the second holder 6, the wiring to the variable drive device 81, the wiring to the fixed drive device 82, the wiring to the adjustment device 9, and the wiring to the imaging device 19 are housed in a storage duct. The storage duct is flexible and houses the piping and cables. The storage duct may house piping or wiring other than the piping and wiring described above. For example, the piping and wiring described above are laid along the robot arm 110 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 100, the piping to the first holder 4, the piping to the second holder 6, the wiring to the variable drive device 81, the piping to the fixed drive device 82, and the wiring to the adjustment device 9 are arranged in the base 3 without protruding from the bottom surface 31b. That is, the storage duct is arranged in the base 3 without protruding from the bottom surface 31b.

[0085] The control device 2 causes the robot 1 to transfer the article W. The control device 2 controls the robot 1 to move the transport vehicle 15, the robot arm 110, and the hand 100, and causes the hand 100 to hold the article W. The control device 2 causes the hand 100, which is holding the article W, to move using the transport vehicle 15 and the robot arm 110, and transfers the article W to a destination position.

[0086] 8 is a diagram showing a schematic hardware configuration of the control device 2. The control device 2 controls the servo motor 14, the first drive device 5, the lifting device 57, the second drive device 8, the adjustment device 9, the transport vehicle 15, the negative pressure generator 17, the air supply device 18, and the imaging device 19. The control device 2 has a processor 21, a storage device 22, a memory 23, and a servo amplifier 24.

[0087] The processor 21 controls the entire control device 2. The processor 21 performs various types of arithmetic processing. For example, the processor 21 is configured with a processor such as a CPU (Central Processing Unit). The processor 21 may also be configured with an MCU (Micro Controller Unit), an MPU (Micro Processor Unit), an FPGA (Field Programmable Gate Array), a PLC (Programmable Logic Controller), or the like.

[0088] The storage unit 22 stores programs and various data to be executed by the processor 21. The storage unit 22 is configured with a non-volatile memory, a hard disk drive (HDD), a solid state drive (SSD), etc. The memory 23 temporarily stores data, etc. For example, the memory 23 is configured with a volatile memory.

[0089] The servo amplifier 24 receives a command from the processor 21 and supplies a current to the servo motor 14. The detection result of the encoder 14a provided in the servo motor 14 is input to the servo amplifier 24. The servo amplifier 24 performs feedback control of the current applied to the servo motor 14 based on the detection result of the encoder 14a.

[0090] 9 is a functional block diagram of the processor 21. The processor 21 realizes various functions by reading out a control program from the storage device 22 into memory and expanding it. Specifically, the processor 21 has a travel controller 25, an arm controller 26, an imaging controller 27, an image processor 28, a lift controller 29, an adjustment controller 210, a belt processor 211, and a suction processor 212.

[0091] The travel controller 25 controls the carrier 15. The travel controller 25 controls the rotation of the motor of the carrier 15, thereby moving the carrier 15, and ultimately the robot 1, to a desired position.

[0092] The arm controller 26 controls the operation of the robot arm 110 so as to move the hand 100 to a position according to a purpose such as imaging the article W, holding the article W, or transporting the article W. The arm controller 26 also performs operations such as selecting an article W to hold from a plurality of articles W. The arm controller 26 generates, as command angles, angles of each joint J according to a target operation of the robot arm 110, and outputs the generated command angles to the servo amplifier 24.

[0093] The imaging controller 27 controls the imaging device 19 to cause the imaging device 19 to perform imaging.

[0094] The image processor 28 processes the image captured by the imaging device 19 to determine the outer shape, position, posture, etc. of the article W. Specifically, the image processor 28 compares the captured image with a template of the article W stored in the memory 22 and extracts the article W in the captured image by a technique such as pattern matching. The image processor 28 outputs the extracted outer shape, position, posture, etc. of the article W to the arm controller 26 and the lift controller 29. The arm controller 26 and the lift controller 29 use the extracted position, posture, etc. of the article W in their respective controls.

[0095] The lifting controller 29 controls the second driving device 8 and the lifting device 57 of the hand 100. Specifically, when adjusting the distance from the first holder 4 to the second holder 6 in the second direction Z, the lifting controller 29 controls the second driving device 8. On the other hand, when moving the first holder 4 or the second holder 6 as a whole in the second direction Z, the lifting controller 29 controls the lifting device 57.

[0096] The adjustment controller 210 controls the first adjustment device 9A and the second adjustment device 9B of the hand 100. Specifically, the adjustment controller 210 controls the first adjustment device 9A when adjusting the position of the first holder 4 in the first direction X. The adjustment controller 210 controls the second adjustment device 9B when adjusting the position of the second holder 6 in the first direction X.

[0097] The belt processor 211 controls the first driving device 5 of the hand 100. Specifically, the belt processor 211 adjusts the positions of the first holder 4 and the second holder 6 in the first direction X by controlling the direction and amount of rotation of the motor 51 of the first driving device 5.

[0098] The suction processor 212 controls the operation of the first holder 4 and the second holder 6. Specifically, the suction processor 212 switches between operating and stopping the negative pressure generator 17, and also switches between connecting and disconnecting the negative pressure generator 17 and the first holder 4 or the second holder 6. In this way, the suction processor 212 switches between suction of the first holder 4 and the second holder 6 and releasing the suction.

[0099] Next, the transfer of the article W by the robot system S will be specifically described. Fig. 10 is a flowchart of the transfer of the article W. Here, the case where the article W piled up at a predetermined start position is transferred to a predetermined destination position will be described as an example.

[0100] First, in step S101, the travel controller 25 controls the carrier 15 to move the robot 1 to the start position.

[0101] Subsequently, in step S102, the arm controller 26 operates the robot arm 110 to move the imaging device 19 to a predetermined imaging position, and the imaging controller 27 causes the imaging device 19 to capture images. As a result, the imaging device 19 acquires images of the stacked articles W.

[0102] Next, in step S103, the image processor 28 extracts the outer shape, position, and posture of the article W from the captured image.

[0103] Thereafter, in step S104, the arm controller 26 selects an article W to be held by the hand 100 from among the multiple articles W based on the extraction result of the image processor 28. For example, when it is assumed that the hand 100 will hold two articles W stacked one above the other at once, the arm controller 26 selects the topmost article W from among the multiple articles W and the article W just below it as the two articles W to be held.

[0104] In step S105, the lifting controller 29 determines the distance from the first holder 4 to the second holder 6 in the second direction Z (hereinafter referred to as the "target distance"). The lifting controller 29 determines the target distance based on the size, position, etc. of the two selected articles W. For example, the lifting controller 29 determines the distance in the second direction Z between the centers of gravity of the front shapes of the two articles W, and sets the determined distance as the target distance.

[0105] The lift controller 29 determines a combination of the second drive units 8 to achieve the target distance. More specifically, if the target distance is within the range obtained by adding the minimum distance from the first holder 4 to the second holder 6 plus the adjustable distance of the variable drive unit 81, the lift controller 29 positions the piston rod 82a of the fixed drive unit 82 at a first position. In this state, the lift controller 29 adjusts the amount of advancement of the rod 81b of the variable drive unit 81 so that the distance from the first holder 4 to the second holder 6 matches the target distance. If the target distance is within the range obtained by adding the minimum distance from the first holder 4 to the second holder 6 plus the travel distance of the fixed drive unit 82 and the adjustable distance of the variable drive unit 81, the lift controller 29 positions the piston rod 82a of the fixed drive unit 82 at a second position. In this state, the lift controller 29 adjusts the amount of advancement of the rod 81b of the variable drive unit 81 so that the distance from the first holder 4 to the second holder 6 matches the target distance.

[0106] In step S106, the adjustment controller 210 determines target adjustment amounts for the positions of the first holder 4 and the second holder 6 in the first direction X. The adjustment controller 210 determines the target adjustment amounts based on the positions in the first direction X of the holding target surfaces of the two selected articles W. The holding target surface is the surface of the article W that comes into contact with the first holder 4 or the second holder 6, and more specifically, the surface that faces the hand 100. For example, the adjustment controller 210 determines the difference in the positions in the first direction X of the holding target surfaces of the two articles W, and sets the determined difference as the target adjustment amount.

[0107] The adjustment controller 210 determines the operating states of the first adjustment device 9A and the second adjustment device 9B to achieve the target adjustment amount. Specifically, the states of the first adjustment device 9A and the second adjustment device 9B may include a state in which the first adjustment device 9A retracts the first retainer 4 and the second adjustment device 9B retracts the second retainer 6, a state in which the first adjustment device 9A retracts the first retainer 4 and the second adjustment device 9B advances the second retainer 6, a state in which the first adjustment device 9A advances the first retainer 4 and the second adjustment device 9B retracts the second retainer 6, and a state in which the first adjustment device 9A advances the first retainer 4 and the second adjustment device 9B advances the second retainer 6. In these states, the positions of the first retainer 4 and the second retainer 6 in the first direction X are different. Specifically, when both the first retainer 4 and the second retainer 6 are retracted, the positions of the first retainer 4 and the second retainer 6 in the first direction X are approximately the same. When the first retainer 4 is in the advanced state and the second retainer 6 is in the retracted state, the first retainer 4 is located further forward in the first direction X than the second retainer 6. When the first retainer 4 is in the retracted state and the second retainer 6 is in the advanced state, the second retainer 6 is located further forward in the first direction X than the first retainer 4. When both the first retainer 4 and the second retainer 6 are in the advanced state, the second retainer 6 is located further forward in the first direction X than the first retainer 4. When both the first retainer 4 and the second retainer 6 are in the advanced state, the difference in position between the first retainer 4 and the second retainer 6 in the first direction X is smaller than when the first retainer 4 is in the retracted state and the second retainer 6 is in the advanced state. When only the second retainer 6 is in the advanced state, the distance between the first retainer 4 and the second retainer 6 in the first direction X is larger than when only the first retainer 4 is in the advanced state. The adjustment controller 210 determines a combination of the operating states of the first adjustment device 9A and the second adjustment device 9B that corresponds to the target adjustment amount. The adjustment controller 210 controls the first adjustment device 9A and the second adjustment device 9B in response to the determination.

[0108] Next, in step S107, the belt processor 211 activates the motor 51 of the first drive device 5 to advance the first holder 4 and the second holder 6 to the first position. As a result, the suction pads 41 of the first holder 4 and the suction pads 61 of the second holder 6 protrude forward beyond the front end of the base plate 31. In addition, the arm controller 26 causes the first holder 4 and the second holder 6 to contact each of the selected two articles W from the sides. Specifically, the arm controller 26 operates the robot arm 110 so that the base plate 31 is at a height approximately equal to or lower than the bottom of the lower of the two articles W. At that height, the arm controller 26 causes the suction pads 41 and 61 to contact the corresponding articles W from the sides. At this time, the suction processor 212 activates the negative pressure generator 17 and establishes electrical conduction between the negative pressure generator 17 and the first holder 4 and the second holder 6. As a result, the first holder 4 and the second holder 6 start to suck. In this way, the first holder 4 and the second holder 6 are sucked onto the two articles W.

[0109] Then, in step S108, the belt processor 211 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. As a result, the article W held by the first holder 4 and the second holder 6 is pulled in the first direction X toward the base plate 31. The article W being pulled in the first direction X, specifically the lower article W of two articles W stacked one above the other, is placed on the conveying surface 52a of the transmission belt 52. By being placed on the conveying surface 52a, the article W is also conveyed by the transmission belt 52 via the frictional force of the conveying surface 52a. In other words, the article W is pulled in the first direction X by the first holder 4, the second holder 6, and the transmission belt 52. Furthermore, when the article W is placed on the conveying surface 52a, it is also placed on the placement surface 31d of the base plate 31. The placement surface 31d has a small coefficient of friction and functions as a sliding surface. That is, the article W is pulled in the first direction X by the first holder 4, the second holder 6, and the transmission belt 52 while the load is supported by the base plate 31. The article W is pulled toward the base plate 31 until the first holder 4 and the second holder 6 reach the second position. In this way, the article W is placed on the base plate 31.

[0110] It should be noted that the suction of the article W by the first holder 4 and the second holder 6 may be released at any timing after the article W has been completely drawn into the base plate 31.

[0111] Next, in step S109, the item W is removed. The arm controller 26 operates the robot arm 110 to move the hand 100 to the destination position of the item W. At this time, the travel controller 25 may also travel the transport vehicle 15 as necessary. When the hand 100 reaches the destination position, the belt processor 211 activates the motor 51 of the first drive device 5 to move the first holder 4 and the second holder 6 forward. The item W is pushed forward by the first holder 4 and the second holder 6, and is pulled forward by the conveying surface 52a of the transmission belt 52. Finally, the item W is placed at the destination position. This completes the transfer of the two items W.

[0112] When the transfer of the two articles W is completed, the processing from step S101 onwards is repeated. The processing from step S101 onwards is repeated until all the articles W at the start position are gone.

[0113] Depending on the size, placement, etc. of the article W, the hand 100 may hold and transport only one article W in one transfer. For example, if the article W is large, the hand 100 may hold one article W using both the first holder 4 and the second holder 6. When holding the last article W in the vertical direction, the hand 100 may hold one article W using only either the first holder 4 or the second holder 6.

[0114] Alternatively, if the target object W is positioned at a recessed position from the surrounding objects W, the hand 100 may hold the target object W using only one of the first holder 4 and the second holder 6. For example, to stably load multiple objects W, the multiple objects W tend to be stacked in an organized manner so that their sides are generally aligned. In such cases, the positions in the first direction X of the sides of the multiple objects W, i.e., the surfaces facing the hand 100, are generally the same. However, the top shelf of the multiple objects W may contain leftover objects W or objects W of varying sizes. Such objects W may be stacked at a recessed position to prevent them from falling. In other words, the position in the first direction X of the side of one object W may differ from the side of the other objects W. Even in other cases, the side of one object W may be positioned further back than the side of the other objects W due to misalignment that occurs during repeated transfers.

[0115] In such cases, adjusting the position of at least one of the first holder 4 and the second holder 6 in the first direction X allows the object W located in a recessed position to be properly held. By moving only the first holder 4 or the second holder 6, rather than the entire hand 100, closer to the object W, it is possible to access the object W located in a narrow space. In other words, since other objects W are placed around the object W located in a recessed position, there is a risk that a part of the hand 100, such as the base 3, may interfere with the other objects W. By advancing the first holder 4 or the second holder 6 in the first direction X, the first holder 4 or the second holder 6 can reach the target object W while avoiding interference of the hand 100 with the other objects W, etc. Furthermore, by adjusting the position of one of the first holder 4 and the second holder 6 in the first direction X independently of the other, it is possible to advance only one of the first holder 4 and the second holder 6 in the first direction X. This allows the first holder 4 or the second holder 6 to be selected as the one most suitable for the target object W.

[0116] Furthermore, after holding the recessed article W using only one of the first holder 4 and the second holder 6, the belt processor 211 may retract the first holder 4 and the second holder 6 in the first direction X until the side of the recessed article W is aligned with the side of another adjacent article W. The adjustment device 9 then retracts both the first holder 4 and the second holder 6, aligning the positions of the first holder 4 and the second holder 6 in the first direction X. The belt processor 211 may move the first holder 4 and the second holder 6 to the two articles W whose sides are aligned in the first direction X, and the suction processor 212 may suck the articles W corresponding to the first holder 4 and the second holder 6, respectively. In this way, the recessed article W is pulled by one of the first holder 4 and the second holder 6 until the side faces are aligned with the other article W, and finally the two articles are held together by both the first holder 4 and the second holder 6. As a result, the transport efficiency can be improved.

[0117] In addition, the maximum adjustment amount in the first direction X of the second holder 6 located above is set to be greater than the maximum adjustment amount in the first direction X of the first holder 4 located below. In other words, the second holder 6 can be advanced further in the first direction X. As described above, an item that is positioned further back than other items is often positioned on the top shelf of multiple stacked items W. Therefore, by advancing the second holder 6 further in the first direction X, more items W can be held.

[0118] Furthermore, when holding one or two articles W placed directly on the floor, in step S106, the arm controller 26 operates the robot arm 110 to bring the base plate 31 as close to the floor as possible. When the article W is placed directly on the floor, the base plate 31 cannot be positioned at substantially the same height as the bottom of the article W or lower. However, in the hand 100, 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 article W held by the first holder 4 onto the base plate 31.

[0119] Furthermore, when holding one or two articles W placed directly on the floor, before pulling the article W into the base plate 31 in step S107, the lifting controller 29 operates the lifting device 57 to move the first holder 4 and the second holder 6 upward in the second direction Z. This causes the article W held by the first holder 4 to be pulled upward. In this state, the belt processor 211 operates the motor 51 of the first drive device 5 to move the first holder 4 and the second holder 6 back to the second position. At an appropriate timing when a portion of the article W reaches above the base plate 31, the lifting controller 29 operates the lifting device 57 to move the first holder 4 downward in the second direction Z. This causes the article W held by the first holder 4 to be placed on the placement surface 31d of the base plate 31 and the conveying surface 52a of the transmission belt 52. Thereafter, the article W is pulled toward the base plate 31 until the first holder 4 and the second holder 6 reach the second position. In this way, the article W is placed on the base plate 31. Note that the process from step S108 onwards is the same as that described above.

[0120] By using the hand 100 in transferring such an article W, the efficiency of transporting the article W can be improved. Specifically, by adjusting the relative positions of the first holder 4 and the second holder 6 in the first direction X using the adjustment device 9, only one of the first holder 4 and the second holder 6 can be advanced in the first direction X. This allows only one of the first holder 4 and the second holder 6 to access an article W positioned further back than other articles W. As a result, even an article W positioned further back can be properly held. Furthermore, even if the side surface of the article W has unevenness in the first direction X, the first holder 4 and the second holder 6 can properly hold the portions that are positioned differently in the first direction X.

[0121] The adjustment device 9 adjusts the position of the first holder 4 in the first direction X independently of the second holder 6, and also adjusts the position of the second holder 6 in the first direction X independently of the first holder 4. This allows either the first holder 4 or the second holder 6 to advance in the first direction X, or allows both the first holder 4 and the second holder 6 to advance in the first direction X. As a result, holding can be flexibly performed to accommodate articles W in various situations and articles W with various shapes of side surfaces.

[0122] Furthermore, the adjustment device 9 can advance the upper second holder 6 further in the first direction X than the lower first holder 4. This allows the second holder 6 to properly hold even an article W that is placed on the top tier of a plurality of stacked articles W and whose sides are not aligned with the other articles W.

[0123] In addition, the hand 100 can adjust the distance from the first holder 4 to the second holder 6 in the second direction Z, i.e., the relative position of the first holder 4 and the second holder 6 in the second direction Z. The hand 100 can appropriately hold two articles W together by appropriately adjusting the distance from the first holder 4 to the second holder 6. This improves the efficiency of transporting the articles W compared to when the hand 100 transports the articles W one by one.

[0124] Furthermore, the size of two articles W that can be held together depends on the relative positions of the first holder 4 and the second holder 6 in the second direction Z. By adjusting the relative positions of the first holder 4 and the second holder 6 in the second direction Z, the range of sizes of two articles W that can be held together can be expanded. Even when holding a single article W using the hand 100, the range of articles W that can be held can be expanded by adjusting the relative positions of the first holder 4 and the second holder 6 in the second direction Z. In other words, the limit of the size of the article W that can be held by the hand 100 depends on the relative positions of the first holder 4 and the second holder 6 in the second direction Z. By increasing the relative positions of the first holder 4 and the second holder 6 in the second direction Z, larger articles W can be held. Furthermore, in order to properly hold an article W, the position at which the article W is held relative to its center of gravity is also important. By adjusting the relative positions of the first holder 4 and the second holder 6 in the second direction Z, the article W can be gripped at an appropriate position relative to its center of gravity. That is, the range of applicable articles W that can be held appropriately can be expanded in relation to the center of gravity of the articles W. In this way, regardless of the number of articles W, the range of applicable articles W that can be held is expanded, thereby improving the transport capacity of the hand 100.

[0125] Movement of the second holder 6 in the second direction Z is achieved by two-stage movement, namely, movement of the first movable body 71 and movement of the second movable body 72. One of the variable drive device 81 and the fixed drive device 82 drives the first movable body 71, and the other of the variable drive device 81 and the fixed drive device 82 drives the second movable body 72. Therefore, the position of the second holder 6 in the second direction Z can be adjusted not only within the adjustable range of the variable drive device 81, but also within the adjustable range of the variable drive device 81 for a fixed amount of movement by the fixed drive device 82. In other words, by realizing part of the movement of the second holder 6 by the fixed drive device 82, the configuration of the second drive device 8 is simplified, and by combining the variable drive device 81 and the fixed drive device 82, the range in which the position of the second holder 6 can be arbitrarily adjusted can be expanded.

[0126] Furthermore, the second direction Z is the up-down direction, the second moving body 72 is disposed above the first moving body 71, the variable drive device 81 drives the first moving body 71, and the fixed drive device 82 drives the second moving body 72. The variable drive device 81 has a more complex structure than the fixed drive device 82, and therefore tends to be heavier than the fixed drive device 82. By disposing the relatively heavy variable drive device 81 at the bottom, the center of gravity of the hand 100 can be lowered.

[0127] Specifically, the variable drive device 81 is an electric cylinder, and the fixed drive device 82 is an air cylinder. Normally, electric cylinders tend to be heavier than air cylinders. By forming the variable drive device 81 from an electric cylinder and using the variable drive device 81 to drive the first movable body 71, it is possible to position the relatively heavy electric cylinder relatively low. This allows the center of gravity of the hand 100 to be lowered.

[0128] As a result of expanding the range of application of the article W in this way, the weight of the article W held by the first holder 4 and the second holder 6 may also become heavier. Since the hand 100 has two transmission belts 52, the force with which the article W is pulled in by the transmission belts 52 is increased. As a result, even a heavier article W can be appropriately pulled toward the base 3 by the first holder 4, the second holder 6, and the transmission belts 52.

[0129] Furthermore, by realizing the movement of the second holder 6 in the second direction Z by combining the variable drive device 81 and the fixed drive device 82, the amount of movement of the second holder 6 can be adjusted within a range larger than the range that can be adjusted by the variable drive device 81.

[0130] Other Embodiments As described above, the above embodiment has been described as an example of the technology disclosed in this application. However, the technology of the present disclosure is not limited to this and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made as appropriate. Furthermore, the components described in the above embodiment can be combined to create new embodiments. Furthermore, the components described in the accompanying 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 exemplify the technology. Therefore, the fact that these non-essential components are described in the accompanying drawings or detailed description should not be interpreted as immediately determining that these non-essential components are essential.

[0131] The robot 1 does not have to have the transport vehicle 15 and the equipment housing section 16. For example, the robot 1 may be fixedly arranged. The application of the hand 100 is not limited to the robot 1, and it may also be applied to an automatic machine that performs a fixed operation.

[0132] The holding of the article W by the hand 100 is not limited to suction. For example, the first holder 4 and the second holder 6 may have multiple fingers that perform opening and closing operations. In other words, the first holder 4 and the second holder 6 may be grippers.

[0133] Furthermore, the holding type of the first holder 4 may be different from the holding type of the second holder 6. For example, the first holder 4 may be a suction pad, and the second holder 6 may be a gripper.

[0134] The first holder 4 and the second holder 6 are moved integrally in the first direction X by the first driving device 5, but are not limited to this. In other words, the first holder 4 and the second holder 6 may be configured to move in the first direction X by independent driving devices.

[0135] The device that drives the first holder 4 and the second holder 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 with a feed screw mechanism. That is, the carriage 56 may be moved in the first direction X by a feed screw.

[0136] The number of transmission belts 52 of the first drive device 5 is not limited to two. The number of transmission belts 52 may be one, or three or more.

[0137] The second holder 6 may be immovable in the second direction Z relative to the first holder 4. In other words, the relative positions of the first holder 4 and the second holder 6 in the second direction Z may be immovable. In this case, the guide 7 and the second drive device 8 are omitted from the hand 100.

[0138] The adjustment device 9 may be capable of adjusting the position in the first direction X of only one of the first holder 4 and the second holder 6. For example, the adjustment device 9 may adjust only the position in the first direction X of the second holder 6, without adjusting the position in the first direction X of the first holder 4. In this case, the first adjustment device 9A is omitted.

[0139] The first drive device 91 of the first adjustment device 9A is not limited to an air cylinder. The first drive device 91 may be an electric cylinder, a feed screw mechanism, a rack and pinion, a link mechanism, a belt drive mechanism, or the like. The first drive device 91 may be capable of arbitrarily changing the adjustment amount of the position of the first holder 4 in the first direction X. The second drive device 95 of the second adjustment device 9B is not limited to an air cylinder. The second drive device 95 may be an electric cylinder, a feed screw mechanism, a rack and pinion, a link mechanism, a belt drive mechanism, or the like. The second drive device 95 may be capable of arbitrarily changing the adjustment amount of the position of the second holder 6 in the first direction X. The first drive device 91 and the second drive device 95 may be different types of second drive devices.

[0140] The configuration for moving the second holder 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 have only the first moving body 71 and the first guide 74, the second holder 6 may be attached to the first moving body 71, and the second drive unit 8 may be only the 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.

[0141] Furthermore, the second drive device 8 may adjust the amount of movement of the second holder 6 in the second direction Z in a stepwise, i.e., discrete, manner rather than continuously. Alternatively, the second drive device 8 may alternatively switch the position of the second holder 6 in the second direction Z between a first position and a second position, i.e., may not be able to adjust the amount of movement of the second holder 6. The second drive device 8 is not limited to an electric cylinder or an air cylinder. The second drive device 8 may also be a feed screw mechanism, a link mechanism, a belt drive mechanism, or the like.

[0142] The second direction Z, which is the movement direction of the second holder 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 100 can collectively hold two articles W arranged side by side using the first holder 4 and the second holder 6. Even in this case, by adjusting the horizontal distance between the first holder 4 and the second holder 6, the articles W can be appropriately held in accordance with articles W of various sizes or weight balances. In this case, the adjustment device 9 adjusts the positions in the first direction X of the first holder 4 and the second holder 6, which are arranged horizontally, independently of each other.

[0143] The hand 100 may include one or more additional holders in addition to the first holder 4 and the second holder 6. The distance of the additional holder from the first holder 4 in the second direction Z may or may not be adjustable. Note that in the case where a plurality of transmission belts 52 are provided or where nothing protrudes from the bottom surface 31b of the base plate 31, the hand 100 may include only the first holder 4 without including the second holder 6.

[0144] The hand 100 does not need to be equipped with the imaging device 19. For example, if the arrangement of the multiple objects W before holding them is known, the imaging device 19 is not necessary. Alternatively, an imaging device separate from the robot 1 may be provided.

[0145] The article W is not limited to a cardboard box. The article W is not limited to a box, and may be a burlap sack for storing grains or the like. In this case, the first holder 4 and the second holder 6 are preferably grippers rather than suction pads.

[0146] The flowchart in Figure 10 is merely an example. Steps in the flowchart may be changed, replaced, added, omitted, etc. as appropriate. The order of steps in the flowchart may also be changed, and serial processing may be performed in parallel.

[0147] The functions performed by the components described herein may be implemented in circuitry or processing circuitry, including general-purpose processors, application-specific processors, integrated circuits, ASICs (Application Specific Integrated Circuits), a CPU (a Central Processing Unit), conventional circuits, and / or combinations thereof, programmed to perform the described functions. A processor includes transistors and other circuits and is considered a circuit or processing circuit. A processor may also be a programmable processor that executes a program stored in a memory.

[0148] In this specification, a circuit, unit, or means is hardware that is programmed to realize or performs the described functions, which may be any hardware disclosed herein or any hardware known to be programmed to realize or perform the described functions.

[0149] If the hardware is a processor considered to be a type of circuitry, the circuit, means, or unit is a combination of hardware and software used to configure the hardware and / or processor.

[0150] [Aspect] The above embodiments are specific examples of the following aspects.

[0151] (Mode 1) A hand 100 includes a base 3, a first holder 4 supported on the base 3 so as to be movable in a predetermined first direction X and to hold an article W, a second holder 6 arranged alongside the first holder 4 in a second direction Z intersecting the first direction X, supported on the base 3 so as to be movable in the first direction X and to hold an article W, a first drive device 5 that moves the first holder 4 and the second holder 6 in the first direction X, and an adjustment device 9 that adjusts the position of one of the first holder 4 and the second holder 6 in the first direction X independently of the other of the first holder 4 and the second holder 6.

[0152] According to this configuration, separately from the movement of the first holder 4 and the second holder 6 in the first direction X by the first drive device 5, the position of one of the first holder 4 and the second holder 6 in the first direction X is adjusted by the adjustment device 9. This allows the relative position of the first holder 4 and the second holder 6 in the first direction X to be adjusted so that only one of the first holder 4 and the second holder 6 advances in the first direction X. As a result, an article W positioned in a position recessed from other articles W can be accessed by only one of the first holder 4 and the second holder 6, and the article W can be held appropriately.

[0153] (Embodiment 2) In the hand 100 described in embodiment 1, the adjustment device 9 includes a first adjustment device 9A that adjusts the position of the first holder 4 in the first direction X independently of the second holder 6, and a second adjustment device 9B that adjusts the position of the second holder 6 in the first direction X independently of the first holder 4.

[0154] According to this configuration, the positions of both the first holder 4 and the second holder 6 in the first direction X can be adjusted independently of each other. The relative positions of the first holder 4 and the second holder 6 in the first direction X can be adjusted more flexibly. As a result, it is possible to more flexibly accommodate articles W placed in various situations and articles W with various shapes.

[0155] (Aspect 3) In the hand 100 described in aspect 1 or aspect 2, the maximum adjustment amount of the position of the first holder 4 in the first direction X by the first adjustment device 9A is different from the maximum adjustment amount of the position of the second holder 6 in the first direction X by the second adjustment device 9B.

[0156] According to this configuration, by selectively using the first adjustment device 9A and the second adjustment device 9B, the variations in the relative positions of the first holder 4 and the second holder 6 in the first direction X can be increased.

[0157] (Aspect 4) In the hand 100 described in any one of aspects 1 to 3, the position of the first holder 4 in the first direction X when the first holder 4 is advanced to the furthest extent from the base 3 in the first direction X by adjustment of the first adjustment device 9A is different from the position of the second holder 6 in the first direction X when the second holder 6 is advanced to the furthest extent from the base 3 in the first direction X by adjustment of the second adjustment device 9B.

[0158] According to this configuration, the distance in the first direction X between the first holder 4 and the second holder 6 can be changed when only the position in the first direction X of the first holder 4 is adjusted, when only the position in the first direction X of the second holder 6 is adjusted, or when the positions in the first direction X of both the first holder 4 and the second holder 6 are adjusted. In other words, the variation in the distance in the first direction X between the first holder 4 and the second holder 6 can be increased. This allows the first holder 4 and the second holder 6 to hold two articles W with various different positions in the first direction X. Alternatively, the first holder 4 and the second holder 6 can hold various articles W including side surfaces with unevenness in the first direction X.

[0159] (Aspect 5) In the hand 100 described in any one of aspects 1 to 4, the second direction Z is the up-down direction, the second holder 6 is positioned higher than the first holder 4, and the position of the second holder 6 in the first direction X when it is farthest from the base 3 in the second direction Z by adjustment of the second adjustment device 9B is farther from the base 3 in the first direction X than the position of the first holder 4 in the first direction X when it is farthest from the base 3 in the first direction X by adjustment of the first adjustment device 9A.

[0160] According to this configuration, the upper second holder 6 can be advanced further in the first direction X than the lower first holder 4. This allows the second holder 6 to properly hold the uppermost article W of the stacked multiple articles W.

[0161] (Mode 6) The hand 100 described in any one of modes 1 to 5 further includes a guide 7 that supports the second holder 6 so that it can move in the second direction Z, and a second drive device 8 that moves the second holder 6 in the second direction Z.

[0162] According to this configuration, in addition to the relative positions of the first holder 4 and the second holder 6 in the first direction X, the relative positions of the first holder 4 and the second holder 6 in the second direction Z can be adjusted. By adjusting the relative positions of the first holder 4 and the second holder 6 in the second direction Z, the range of applicable articles W that can be held by the hand 100 can be expanded. For example, two parallel articles W can be held by the first holder 4 and the second holder 6, respectively. In this case, by adjusting the distance between the first holder 4 and the second holder 6 in the second direction Z to match the sizes of the two articles W, articles W of various sizes can be appropriately held. Even when one article W is held by the first holder 4 and the second holder 6, by adjusting the distance between the first holder 4 and the second holder 6 in the second direction Z, articles W of various sizes can be appropriately held. As a result, the range of applicable articles W that can be held can be expanded, and the transport capacity of the hand 100 can be improved. [Explanation of symbols]

[0163] 100 hands 3. Bass 4 1st retainer 5. First drive unit 6 Second retainer 7 Guide 71 First Mobile Unit 72 Second Mobile Unit 74 First Guide 75 Second Guide 8 Second drive unit 81 Variable Drive 82 Fixed Drive 9 Adjustment device 9A 1st regulator 9B 2nd regulator X 1st direction Z 2nd direction W Item

Claims

1. With the base, a first holder that is supported movably in a predetermined first direction relative to the base and that holds an article; a second holder that is arranged alongside the first holder in a second direction intersecting the first direction, is supported on the base so as to be movable in the first direction, and holds an article; a first drive device that moves the first holder and the second holder in the first direction; a hand including an adjustment device that adjusts the position of one of the first holder and the second holder in the first direction independently from the other of the first holder and the second holder;

2. The hand according to claim 1, The adjustment device includes a first adjustment device that adjusts the position of the first holder in the first direction independently from the second holder, and a second adjustment device that adjusts the position of the second holder in the first direction independently from the first holder.

3. The hand according to claim 2, A hand in which a maximum adjustment amount of the position of the first holder in the first direction by the first adjustment device is different from a maximum adjustment amount of the position of the second holder in the first direction by the second adjustment device.

4. The hand according to claim 2, A hand in which the position of the first holder in the first direction when it is advanced furthest from the base in the first direction by adjustment of the first adjustment device is different from the position of the second holder in the first direction when it is advanced furthest from the base in the first direction by adjustment of the second adjustment device.

5. The hand according to claim 4, the second direction is an up-down direction, the second retainer is disposed above the first retainer, A hand in which the position of the second holder in the first direction when it is farthest from the base in the second direction by adjustment of the second adjustment device is farther from the base in the first direction than the position of the first holder in the first direction when it is farthest from the base in the first direction by adjustment of the first adjustment device.

6. The hand according to any one of claims 1 to 5, a guide that supports the second retainer so that the second retainer is movable in the second direction; a second drive device that moves the second holder in the second direction.

Images