Robot control device and robot control method

Abstract

A transport system and an automatic teaching method are provided that can reduce the labor required for teaching a robot. [Solution] The transport system includes a robot control unit (620). The robot control unit (620) operates the robot to detect the positions of three mutually separated parts (911A, 911B, 911C) of a pallet stocker (31), and generates a user coordinate system in the pallet stocker (31) based on the detected positions. The robot control unit (620) operates the robot to detect the position of a specific part (921) of a shelf board (510), and calculates the position of a gripper (120A) in the user coordinate system based on the detected position and the positional relationship between the specific part (921) and a gripper (120A) of a pallet (410) when the pallet is placed on the shelf board (510).

Description

[Technical field]

[0001] The present invention relates to a robot control device and Robot Control Method Regarding. [Background technology]

[0002] For example, JP 2017-102825 A (Patent Document 1) discloses a composite system including a machine tool having a work fixing jig that can move integrally with the table, a work stocker for storing workpieces, and a robot system having a robot that supplies and removes workpieces between the work fixing jig and the work stocker. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-102825 A Summary of the Invention [Problem to be solved by the invention]

[0004] As disclosed in the above-mentioned Patent Document 1, there is known a transport system that uses a robot to transport various transport objects. In such a transport system, a teaching operation is required to teach the robot how to move, and there is a demand to reduce the labor required for this teaching operation.

[0005] An object of the present invention is to provide a transfer system and an automatic teaching method that can reduce the labor required for teaching a robot. [Means for solving the problem]

[0006] A transport system according to the present invention includes a pallet stocker having a shelf on which a pallet can be placed and for storing the pallet, a robot having a hand capable of gripping a gripper of the pallet and transporting the pallet, and a robot control unit for controlling the robot. The robot control unit operates the robot to detect positions of three mutually distant parts of the pallet stocker, and generates a user coordinate system for the pallet stocker based on the positions of the three detected parts. The robot control unit operates the robot to detect a position of a specific part of the shelf, and calculates the position of the gripper in the user coordinate system based on the position of the detected specific part and the positional relationship between the specific part and the gripper when the pallet is placed on the shelf.

[0007] An automatic teaching method according to the present invention is an automatic teaching method for a transport system including a pallet stocker having a shelf on which a pallet can be placed and for storing the pallets, and a robot having a hand capable of gripping a gripping portion of the pallet and transporting the pallet. The automatic teaching method includes the steps of operating the robot to detect positions of three mutually distant parts of the pallet stocker and generating a user coordinate system for the pallet stocker based on the positions of the three detected parts, and operating the robot to detect a position of a specific part of the shelf and calculating a position of the gripping part in the user coordinate system based on the detected position of the specific part and the positional relationship between the specific part and the gripping part when the pallet is placed on the shelf. Effect of the Invention

[0008] According to the invention, it is possible to provide a transfer system and an automatic teaching method capable of reducing the labor required for teaching a robot. [Brief description of the drawings]

[0009] [Figure 1] 1 is a top view showing a transport system according to an embodiment of the present invention; [Diagram 2]FIG. 2 is a simplified top view of the transport system in FIG. [Diagram 3] FIG. 2 is a perspective view showing the relationship of a pallet, a work hand, a shelf board, and a teaching hand to a master hand. [Figure 4] FIG. 2 is a perspective view showing a master hand. [Diagram 5] FIG. 13 is another perspective view showing the master hand. [Figure 6] FIG. 2 is a diagram for explaining the structure of a master hand. [Figure 7] FIG. 2 is a perspective view showing a pallet stocker in FIG. [Figure 8] 8 is a perspective view showing a pallet stocker in the area surrounded by a two-dot chain line VIII in FIG. 7. [Figure 9] FIG. 2 is a block diagram showing a control system of the transport system in FIG. [Figure 10] FIG. 2 is a top view showing a first step of workpiece machining using the work stocker. [Figure 11] FIG. 11 is a top view showing a second step of workpiece machining using the work stocker. [Figure 12] FIG. 11 is a top view showing a third step of workpiece machining using the work stocker. [Figure 13] FIG. 11 is a top view showing a fourth step of workpiece machining using the work stocker. [Figure 14] FIG. 11 is a top view showing a fifth step of workpiece machining using the work stocker. [Figure 15] FIG. 11 is a top view showing a sixth step of workpiece machining using the work stocker. [Figure 16] FIG. 2 is a top view showing a first step of workpiece machining using the setup station. [Figure 17] FIG. 11 is a top view showing a second step of workpiece machining using the setup station. [Figure 18] FIG. 11 is a top view showing a third step of workpiece machining using the setup station. [Figure 19] FIG. 11 is a top view showing a fourth step of workpiece machining using the setup station. [Figure 20] FIG. 11 is a top view showing a fifth step of workpiece machining using the setup station. [Figure 21] FIG. 11 is a top view showing a first step of inserting a pallet into the pallet stocker. [Figure 22] FIG. 11 is a top view showing a second step of inserting pallets into the pallet stocker. [Diagram 23] FIG. 11 is a top view showing a third step of inserting pallets into the pallet stocker. [Figure 24] 1 is a flowchart showing an overall flow of a robot teaching operation. [Diagram 25] FIG. 13 is a front view showing the pallet stocker during automatic teaching. [Figure 26] 11 is a front view showing the positional relationship between a reference hole and a first gripping portion of a pallet stored in a work stocker. FIG. [Figure 27] FIG. 2 is a block diagram showing a control system for automatic teaching. [Figure 28] FIG. 13 is a perspective view showing automatic teaching for generating a user coordinate system. [Figure 29] FIG. 13 is a diagram showing a user coordinate system generation screen on a display unit. [Diagram 30] FIG. 13 is a perspective view showing automatic teaching for setting a grip position. [Diagram 31] FIG. 13 is a diagram showing a grip position setting screen on the display unit. [Diagram 32] 11 is a flowchart showing a flow of steps of automatic teaching for generating a user coordinate system. [Diagram 33] 10 is a flowchart showing a flow of steps of automatic teaching for setting a grip position. [Diagram 34] FIG. 13 is a side view showing a state of manual teaching. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described with reference to the accompanying drawings, in which the same or corresponding components are designated by the same reference numerals.

[0011] Fig. 1 is a top view showing a transfer system according to an embodiment of the present invention, Fig. 2 is a top view showing a simplified version of the transfer system shown in Fig. 1.

[0012] 1 and 2, a transfer system 100 in this embodiment has a robot 21 and a robot base 22.

[0013] As a typical example, the robot 21 is a six-axis articulated robot. The robot 21 has a base unit 26, a first arm 27, a second arm 28, a hand attachment unit 29, and a master hand 210.

[0014] The robot base 22 is a support platform that supports the robot 21, and is fixed to the floor of a factory or the like. The robot base 22 is made of metal. The base unit 26 is connected to the robot base 22 so as to be rotatable about a central axis of rotation 101. The central axis of rotation 101 is an imaginary straight line that corresponds to the center of rotation of the robot 21, and extends in the vertical direction.

[0015] The first arm 27 is attached to the base 26. The first arm 27 is rotatable about a rotation center axis 102 disposed at a mounting portion (joint portion) of the first arm 27 relative to the base 26. The second arm 28 is attached to the first arm 27. The second arm 28 is rotatable about a rotation center axis 103 disposed at a mounting portion (joint portion) of the second arm 28 relative to the first arm 27, and is capable of rotating the hand mounting portion 29 about a rotation center axis 104 along the second arm 28. The hand mounting portion 29 is attached to the second arm 28. The hand mounting portion 29 is rotatable about a rotation center axis 105 disposed at a mounting portion (joint portion) of the hand mounting portion 29 relative to the second arm 28, and is capable of rotating the master hand 210 about a rotation center axis 106 along the hand mounting portion 29.

[0016] The master hand 210 is attached to a hand attachment portion 29 as an end effector. The master hand 210 is attached to the second arm 28 so as to be rotatable around a rotation central axis 105. The master hand 210 is attached to the second arm 28 via the hand attachment portion 29. The second arm 28 is attached to the first arm 27 so as to be rotatable around a rotation central axis 103.

[0017] The robot 21 further has a plurality of drive servo motors 23 for operating the base portion 26, the first arm 27, the second arm 28, the hand attachment portion 29 and the master hand 210 respectively about the above-mentioned multiple axes (rotation center axis 101, rotation center axis 102, rotation center axis 103, rotation center axis 104, rotation center axis 105 and rotation center axis 106) (see Figures 9 and 27 described below).

[0018] 1, a region in which the master hand 210 moves in the transport system 100 (operating region of the master hand 210) is indicated by a two-dot chain line 111. In addition, a two-dot chain line 112 extending in an arc shape centered on the pivot central axis 101 indicates the maximum region in which the master hand 210 can move.

[0019] The transfer system 100 further includes a machine tool 10 (10S, 10T), a pallet stocker 31 (31S, 31T), a work stocker 71, a hand stocker 81, and a setup station 61 (61S, 61T).

[0020] The machine tool 10 (10S, 10T), the pallet stocker 31 (31S, 31T), the work stocker 71, the hand stocker 81, and the setup station 61 (61S, 61T) are provided around the robot base 22. The machine tool 10 (10S, 10T), the pallet stocker 31 (31S, 31T), the work stocker 71, the hand stocker 81, and the setup station 61 (61S, 61T) are lined up along the circumferential direction of the turning central axis 101. In the top view shown in FIG. 1 , at least a part of each of the machine tool 10 (10S, 10T), the pallet stocker 31 (31S, 31T), the work stocker 71, the hand stocker 81, and the setup station 61 (61S, 61T) overlaps with the operating area of ​​the master hand 210 indicated by the two-dot chain line 111.

[0021] The robot in the present invention is not limited to the six-axis articulated robot described above, and may be, for example, a robot (gantry loader) capable of moving an object to be transported in three mutually perpendicular axial directions. Also, the machine tool, pallet stocker, work stocker, hand stocker, and setup station may be arranged in a straight line.

[0022] The machine tool 10 is a machining center that processes a workpiece by bringing a rotating tool into contact with the workpiece. The machine tool 10 is an NC (Numerically Controlled) machine tool in which various operations for processing the workpiece are automated by numerical control using a computer.

[0023] Machine tool 10 may be a multi-tasking machine having a turning function using a fixed tool and a milling function using a rotating tool, or may be an AM / SM hybrid machine capable of additive manufacturing and subtractive manufacturing of a workpiece. Machine tool 10S and machine tool 10T may be the same type of machine tool or different types of machine tools.

[0024] Machine tool 10 has a cover body 14. Cover body 14 defines the exterior of machine tool 10 and defines machining area 12. Machining area 12 is a space where machining of a workpiece is performed, and is sealed by cover body 14 to prevent foreign matter such as cutting chips or cutting oil resulting from workpiece machining from leaking out of the machining area.

[0025] The cover body 14 is provided with an opening 16. The robot 21 transports an object to be transported, such as a workpiece W or a pallet 410, to the processing area 12 through the opening 16. The opening 16 is provided with a door or shutter that can be opened and closed.

[0026] In the machining area 12, a tool spindle for rotating a tool, a table for holding a pallet 410, and the like are provided.

[0027] Machine tool 10 further has an operation panel 18. Operation panel 18 includes a control device that controls the operation of machine tool 10, a display unit (display) for displaying various information related to machining, and an operation unit that accepts various operations on machine tool 10.

[0028] Machine tool 10S and machine tool 10T are provided at positions facing each other across robot base 22. Machine tool 10S and machine tool 10T are provided at angular positions shifted by 180° in the circumferential direction about central turning axis 101.

[0029] Pallet stocker 31 is a device for storing pallets 410. Pallet stocker 31 is provided between machine tool 10S and machine tool 10T in the circumferential direction centered on turning central axis 101. Pallet stocker 31S and pallet stocker 31T are provided adjacent to each other in the circumferential direction centered on turning central axis 101.

[0030] The work stocker 71 is a device for storing the workpieces W. The work stocker 71 has a shelf structure on which the workpieces W can be placed. The hand stocker 81 is a device for storing various hands such as the work hand 310 and the teaching hand 710 described below. The hand stocker 81 has a shelf structure on which the various hands can be placed.

[0031] The work stocker 71 and the hand stocker 81 are provided between the machine tool 10S and the machine tool 10T in the circumferential direction centered on the central turning axis 101. The work stocker 71 and the hand stocker 81 are provided in a position facing the pallet stocker 31 (31S, 31T) with the robot base 22 in between. The work stocker 71 and the hand stocker 81 are provided next to each other above and below.

[0032] Setup station 61 is a device that mainly performs the operation of mounting and removing workpieces W onto and from pallet 410. A pallet mounting table (not shown) on which pallet 410 can be placed is installed in setup station 61. Setup station 61 is provided between workpiece stocker 71 and hand stocker 81, and machine tool 10 in the circumferential direction about central axis of rotation 101. Setup station 61 is provided adjacent to workpiece stocker 71 and hand stocker 81 in the circumferential direction about central axis of rotation 101.

[0033] The setup station 61S and the setup station 61T are provided on both sides of the work stocker 71 and the hand stocker 81 in the circumferential direction about the central turning axis 101.

[0034] The number of each device of machine tool 10, pallet stocker 31, work stocker 71, hand stocker 81 and setup station 61 provided in transfer system 100 is not particularly limited.

[0035] The conveyance system 100 further includes a plurality of fences 56 (56h, 56i, 56j, 56k). The fences 56 rise from the floor of a factory or the like. In the top view shown in FIG. 1, the fence 56h extends between the machine tool 10S and the pallet stocker 31S. In the top view shown in FIG. 1, the fence 56i extends between the pallet stocker 31T and the machine tool 10T. In the top view shown in FIG. 1, the fence 56j extends between the machine tool 10T and the setup station 61T. In the top view shown in FIG. 1, the fence 56k extends between the setup station 61S and the machine tool 10S.

[0036] The robot 21 is disposed in a space 113 surrounded by a plurality of fences 56 (56h, 56i, 56j, 56k), the machine tool 10 (10S, 10T), the pallet stocker 31 (31S, 31T), the work stocker 71, the hand stocker 81, and the setup station 61 (61S, 61T). The operating area of ​​the master hand 210 indicated by a two-dot chain line 111 is included in the space 113.

[0037] An operator cannot access the pallet stocker 31 from outside the space 113. An operator can load a pallet 410 into the pallet stocker 31 or retrieve the pallet 410 from the pallet stocker 31 through the setup station 61. An operator can access the work stocker 71 and the hand stocker 81 from outside the space 113. An operator can load an unprocessed workpiece W into the conveyance system 100 or retrieve a processed workpiece W' from the conveyance system 100 through the work stocker 71. An operator can load various hands into the conveyance system 100 or retrieve them from the conveyance system 100 through the hand stocker 81.

[0038] The transport system 100 further includes a transport operation panel 51. The transport operation panel 51 includes a control device 610 for controlling the operation of the robot 21, a display unit 670 for displaying various information related to transport by the robot 21, and an operation unit for receiving various operations on the robot 21 (see Figs. 9 and 27 described later). In this embodiment, the display unit 670 is configured with a touch panel display that can be operated by an operator, and performs part of the function of the operation unit. The operation unit may be configured with various buttons that can be pressed, numeric keys that can input numbers, a dial, or the like.

[0039] The transport operation panel 51 is attached to the work stocker 71 and the hand stocker 81. The position where the transport operation panel 51 is provided is not particularly limited.

[0040] Fig. 3 is a perspective view showing the relationship of the pallet, the work hand, the shelf board, and the teaching hand with respect to the master hand. Fig. 4 and Fig. 5 are perspective views showing the master hand. Fig. 6 is a diagram for explaining the structure of the master hand.

[0041] 3 to 6, the master hand 210 has a clamping mechanism 220. The clamping mechanism 220 is configured to be operable between a clamped state in which the gripping portion 120 is held and an unclamped state in which the gripping portion 120 is released.

[0042] 4 to 6, grip portion 120 has a grip shape centered on central axis 126. Grip portion 120 is provided with groove portion 121. Groove portion 121 is recessed from the outer circumferential surface of grip portion 120 and has a groove shape that circles around central axis 126.

[0043] The clamp mechanism 220 has the appearance of a block body. The clamp mechanism 220 is provided with a grip insertion hole 221. The grip insertion hole 221 is open in one direction.

[0044] The clamp mechanism 220 is made of a cylinder piston. The clamp mechanism 220 has a pair of pistons 226. The pair of pistons 226 extend in a shaft shape along a central axis 231 that is perpendicular to the central axis 126 and intersects with the grip insertion hole 221. The pair of pistons 226 face each other with a gap in between in the axial direction of the central axis 231. The pair of pistons 226 are supported so as to be slidable in the axial direction of the central axis 126. A protrusion 227 that can engage with the groove 121 is provided at the tip of each piston 226.

[0045] When the master hand 210 grips the grip portion 120, the master hand 210 is positioned so that the clamp mechanism 220 faces the grip portion 120. The master hand 210 is moved linearly in a direction approaching the grip portion 120 to insert the grip portion 120 into the grip insertion hole 221. The pair of pistons 226 are slid in a direction approaching each other by supplying air pressure or the like, thereby operating the clamp mechanism 220 from the unclamped state to the clamped state. As a result, the protrusions 227 of the pair of pistons 226 advance into the grip insertion hole 221 and engage with the grooves 121.

[0046] When the master hand 210 releases the gripping portion 120, the pair of pistons 226 are slid away from each other to operate the clamping mechanism 220 from the clamped state to the unclamped state. This causes the protrusions 227 of the pair of pistons 226 to retract from the grip insertion hole 221 and come out of the groove portion 121. The master hand 210 is moved linearly away from the gripping portion 120 to remove the gripping portion 120 from the grip insertion hole 221.

[0047] 5, the conveyance system 100 further includes a sensor 230. The sensor 230 is a sensor capable of detecting the presence or absence of an object, and is, for example, a non-contact photoelectric sensor. The sensor 230 may be a proximity sensor or a contact sensor such as a limit switch.

[0048] The sensor 230 is mounted on the robot 21. The sensor 230 is mounted on the master hand 210. When the sensor 230 is a photoelectric sensor, the emission direction of light from the sensor 230 may be parallel to the approach and retreat direction of the gripper 120 relative to the master hand 210.

[0049] 3, the transport system 100 further includes a pallet 410 for holding the workpiece. The transport system 100 includes a plurality of pallets 410.

[0050] Pallet 410 is made of a metal plate and has a substantially rectangular shape when viewed from above. A clamping mechanism for holding pallet 410 is built into a table of machine tool 10. A jig such as an tombstone or a clamping device is attached onto pallet 410, and a workpiece is held on pallet 410 via the jig.

[0051] The pallet 410 has a first gripping portion 120A. The first gripping portion 120A corresponds to the above-mentioned gripping portion 120, and is configured to be able to be gripped by the master hand 210. The first gripping portion 120A is provided on a side surface of the pallet 410. The first gripping portion 120A is provided detachably with respect to the pallet 410.

[0052] The master hand 210 grips the first gripping portion 120A, whereby the robot 21 can transport the pallet 410.

[0053] Fig. 7 is a perspective view showing the pallet stocker in Fig. 1. Fig. 8 is a perspective view showing the pallet stocker in the area surrounded by the two-dot chain line VIII in Fig. 7.

[0054] 7 and 8 and other figures showing pallet stocker 31 show X-, Y-, and Z-axes, which are coordinate axes of pallet stocker 31. The X-axis extends horizontally corresponding to the width direction (left-right direction) of pallet stocker 31, the Y-axis extends vertically, and the Z-axis extends horizontally corresponding to the depth direction (front-back direction) of pallet stocker 31. The X-, Y-, and Z-axes are three axes that are perpendicular to one another.

[0055] 3, 7 and 8, pallet stocker 31 has a frame body 550, a plurality of support portions 560, and a plurality of shelf boards 510. As shown in FIG.

[0056] The frame body 550 forms a rectangular parallelepiped frame body. The frame body 550 forms a rectangular parallelepiped frame body with the X-axis direction and the Y-axis direction being the longitudinal direction and the Z-axis direction being the lateral direction. The frame body 550 has four pillars 551. The four pillars 551 are arranged at the four corners of the frame body 550 when viewed from above. Each pillar 551 extends in the Y-axis direction (up and down direction).

[0057] The support portion 560 is configured to be capable of supporting the shelf board 510. The multiple support portions 560 are arranged at intervals from one another in the vertical direction.

[0058] The support portion 560 has a pair of plates 561 on the left and right. The pair of plates 561 are provided with a gap between them in the X-axis direction. The plate 561 extends in the Z-axis direction while forming an L-shaped cross section when cut by the X-axis-Y-axis plane. Both ends of the plate 561 in the Z-axis direction are respectively connected to two pillars 551 aligned in the Z-axis direction.

[0059] The shelf board 510 is configured to be able to place the pallet 410. When viewed from above, the shelf board 510 has a rectangular shape with the X-axis direction being the longitudinal direction and the Z-axis direction being the lateral direction, and has a plate shape with the Y-axis direction being the thickness direction.

[0060] The shelf board 510 has a pair of vertical frames 532 on the left and right sides and a pair of horizontal frames 531 on the front and back sides. The pair of vertical frames 532 are provided at a distance from each other in the X-axis direction. The pair of vertical frames 532 are provided at both ends of the shelf board 510 in the X-axis direction. The vertical frame 532 is made of a plate material whose thickness direction is in the Y-axis direction and extends in the Z-axis direction. The pair of horizontal frames 531 are provided at a distance from each other in the Z-axis direction. The horizontal frame 531 extends in the X-axis direction and is connected at both ends to the pair of vertical frames 532.

[0061] 7 and 8, the shelf board 510 is supported by a support portion 560. The pair of vertical frames 532 are placed on a pair of plates 561. The pair of vertical frames 532 support the weight of the shelf board 510.

[0062] As shown in FIG. 8, the support portion 560 further has a pin 562. The pin 562 is provided on a plate 561. The pin 562 protrudes upward from the top surface of the plate 561. A pin hole 533 is provided in the vertical frame 532. The pin hole 533 is a through hole that penetrates the vertical frame 532 in the Y-axis direction. The pin 562 is disposed in the pin hole 533. This configuration prevents the shelf board 510 from shifting in position relative to the support portion 560.

[0063] As shown in FIG. 3, the shelf 510 further includes a plurality of pallet supports 520 (520p, 520q, 520r).

[0064] Each pallet support portion 520 is configured to be able to support a pallet 410. Each pallet support portion 520 is configured with four taper cone receiving portions 525 arranged at intervals in the X-axis direction and the Z-axis direction. The taper cone receiving portions 525 are provided on a horizontal frame 531. The taper cone receiving portions 525 protrude upward from the top surface of the horizontal frame 531. The taper cone receiving portions 525 have a concave shape capable of receiving a taper cone provided on the bottom surface of the pallet 410.

[0065] Pallet support portion 520p, pallet support portion 520q, and pallet support portion 520r are aligned in the X-axis direction in the order listed.

[0066] The shelf 510 is capable of supporting pallets 410 of different sizes. For example, the shelf 510 is capable of supporting pallets 410 of 400 mm×400 mm size and pallets 410 of 500 mm×500 mm size. When the pallets 410 are 400 mm×400 mm size, three pallets 410 can be supported on the shelf 510 using the pallet support parts 520p, pallet support parts 520q, and pallet support parts 520r. When the pallets 410 are 500 mm×500 mm size, two pallets 410 can be supported on the shelf 510 using the pallet support parts 520p and pallet support parts 520r.

[0067] As shown in Figs. 3 and 7, the shelf board 510 has a second gripping portion 120B. The second gripping portion 120B corresponds to the gripping portion 120 described above, and is configured to be grippable by the master hand 210. The second gripping portion 120B is provided at the center position of the shelf board 510 in the X-axis direction. The second gripping portion 120B protrudes in the Z-axis direction from the front surface of the shelf board 510 (horizontal frame 531). The second gripping portion 120B is provided below the pallet support portion 520 (tapered cone receiving portion 525). The second gripping portion 120B is provided detachably with respect to the shelf board 510.

[0068] The master hand 210 grips the second gripping portion 120B, thereby enabling the robot 21 to transport the shelf board 510. The robot 21 changes the position of the shelf board 510 between a plurality of supports 560 in the pallet stocker 31. The change of the position of the shelf board 510 using the robot 21 will be described in detail later.

[0069] 3, the work hand 310 is configured to be able to grip a work W. The work hand 310 has a pair of gripping claws 320. The pair of gripping claws 320 face each other with a gap therebetween.

[0070] The work hand 310 is configured to be operable between a clamped state in which the work W is gripped by the pair of gripping jaws 320, and an unclamped state in which the pair of gripping jaws 320 release the work W. By sliding the pair of gripping jaws 320 in directions in which they approach each other, the work hand 310 moves from the unclamped state to the clamped state. By sliding the pair of gripping jaws 320 in directions in which they move away from each other, the work hand 310 moves from the clamped state to the unclamped state.

[0071] The work hand 310 has a piston cylinder 330 and a servo motor 340 as a power source for slidingly moving the pair of gripping jaws 320 (see FIG. 9 described later).

[0072] The workpiece hand 310 further has a third gripping portion 120C. The third gripping portion 120C corresponds to the gripping portion 120 described above, and is configured to be able to be gripped by the master hand 210. The third gripping portion 120C has a grip shape that extends in a direction perpendicular to the sliding direction of the pair of gripping jaws 320. The third gripping portion 120C is provided detachably to the workpiece hand 310.

[0073] The master hand 210 grips the third gripping portion 120C, whereby the workpiece hand 310 can be attached to the robot 21. The robot 21 can transport the workpiece W using the workpiece hand 310.

[0074] The teaching hand 710 has a touch probe 720. The teaching hand 710 is used for teaching the robot 21 using the touch probe 720.

[0075] The teaching hand 710 further has a fourth gripping portion 120D. The fourth gripping portion 120D corresponds to the gripping portion 120 described above, and is configured to be able to be gripped by the master hand 210. The touch probe 720 has a pin-shaped contactor 720g that comes into contact with the measurement target. The fourth gripping portion 120D has a grip shape that extends in a direction perpendicular to the direction in which the contactor 720g extends in a pin shape. The fourth gripping portion 120D is provided detachably to the teaching hand 710.

[0076] The teaching hand 710 can be attached to the robot 21 by the master hand 210 gripping the fourth gripping portion 120D.

[0077] The first gripping portion 120A, the second gripping portion 120B, the third gripping portion 120C, and the fourth gripping portion 120D have the same grip shape. The master hand 210 is configured to be able to selectively grip one of the gripping portions 120 among the first gripping portion 120A, the second gripping portion 120B, the third gripping portion 120C, and the fourth gripping portion 120D.

[0078] Fig. 9 is a block diagram showing a control system of the transfer system in Fig. 1. Referring to Fig. 9, the transfer system 100 further includes a control device 610.

[0079] Each component of the control device 610 is realized by hardware including a computing unit such as a CPU (Central Processing Unit) and various computer processors, a storage device such as a memory or storage, and a wired or wireless communication line connecting them, and software stored in the storage device and supplying processing instructions to the computing unit. The computer program constituting the software may be composed of a device driver, an operating system, various application programs located in higher layers thereof, or a library providing common functions to these programs. The computer program may be recorded in a computer-readable storage medium, or may be recorded in a non-transitory computer-readable storage medium. The computer program may be included in a computer program product. Each block described below indicates a functional unit block.

[0080] The control device 610 has an operation receiving unit 660 and a robot control unit 620. The operation receiving unit 660 receives an operation by an operator via a display unit 670 (operation unit) formed of, for example, a touch panel display. The operation receiving unit 660 outputs a signal according to the operation by the operator to the robot control unit 620.

[0081] The robot control unit 620 controls the operation of the robot 21 (including the operation of the work hand 310 attached to the master hand 210).

[0082] The robot control unit 620 has a program storage unit 621 , a program analysis unit 622 , an axis control unit 623 , a hand control unit 624 , and a parameter storage unit 625 .

[0083] The program storage unit 621 stores various operation programs 641 that command the operation of the robot 21. The operation programs 641 stored in the program storage unit 621 include, for example, operation commands that define the movement and stopping of the robot 21, position commands that define the position and orientation (posture) of the master hand 210, path commands that define movement paths such as linear movement and circular movement, and speed commands that define the movement speed. The operation programs 641 are input via an input / output device 630 connected to the robot control unit 620 and stored in the program storage unit 621.

[0084] The operation program 641 is written in, for example, a language called SLIM (Standard Language for Industrial Manipulators). A specific position and orientation (posture) in each position command included in the operation program 641 is obtained by operating the robot 21 through a manual operation called a teaching operation. As the robot 21 operates through the teaching operation, the rotation angle positions of the drive servo motors 23 built into the robot 21 are acquired as parameters, and the acquired parameters are stored in the parameter storage unit 625 via the input / output device 630.

[0085] The program analysis unit 622 reads out the operation program 641 to be executed from the operation program 641 stored in the program storage unit 621 in response to a signal from the operation acceptance unit 660. The program analysis unit 622 analyzes the operation program 641, extracts commands related to movement, and transmits the commands to the axis control unit 623. The program analysis unit 622 analyzes the operation program 641, extracts commands related to hand operation, and transmits the commands to the hand control unit 624.

[0086] The axis control unit 623 controls the multiple drive servo motors 23 in response to commands from the program analysis unit 622. The hand control unit 624 controls the master hand 210 and / or the work hand 310 in response to commands from the program analysis unit 622.

[0087] Specifically, the axis control unit 623 reads out parameters corresponding to each position command from the parameter storage unit 625, generates rotation commands (control signals) for each drive servo motor 23 so that the rotation angle position of each drive servo motor 23 becomes the read rotation angle position, the movement path of the master hand 210 becomes the commanded movement path (linear movement or circular movement), and further moves at a commanded speed, and transmits the generated rotation commands (control signals) to each drive servo motor 23. The drive servo motors 23 are supplied with drive currents corresponding to the rotation commands from the axis control unit 623, thereby moving the master hand 210 to the commanded position.

[0088] The hand control unit 624 generates an air valve opening / closing command in response to a command from the program analysis unit 622 so that the pair of pistons 226 perform a sliding motion, and transmits the opening / closing command to the clamp mechanism 220. The hand control unit 624 generates an air valve opening / closing command in response to a command from the program analysis unit 622 so that the pair of gripping claws 320 perform a sliding motion, and transmits the opening / closing command to the piston cylinder 330, and generates a rotation command (control signal) for the servo motor 340, and transmits the rotation command to the servo motor 340.

[0089] Next, a specific example of how the robot 21 is used in the transport system 100 will be described. Figures 10 to 15 are top views showing steps of workpiece machining using a work stocker. Figures 10 to 15 correspond to Figure 2.

[0090] 2, in an initial state, a plurality of pallets 410 are stored in the pallet stocker 31. A jig (not shown), such as an tombstone or a clamping device, is mounted on the pallet 410. Unmachined workpieces W are stored in the work stocker 71. A plurality of work hands 310 and a teaching hand 710 are stored in the hand stocker 81. The work hand 310 may have a pair of gripping jaws 320 that are different in shape or size from each other among the plurality of work hands 310.

[0091] 9 and 10, the control device 610 (robot control unit 620) controls the robot 21 so that the master hand 210 grips the first gripper 120A of the pallet 410 stored in the pallet stocker 31.

[0092] In this step, the master hand 210 moves towards the pallet stocker 31 and is positioned so as to face the first gripping portion 120A of the pallet 410 in the Z-axis direction. As the master hand 210 moves in the Z-axis direction, the first gripping portion 120A is inserted into the grip insertion hole 221. The master hand 210 grips the first gripping portion 120A. As the master hand 210 moves upward, the pallet 410 is lifted from the shelf board 510.

[0093] 9 and 11, next, the control device 610 (robot control unit 620) controls the robot 21 so that the pallet 410 gripped by the master hand 210 moves to the machining area 12 of the machine tool 10.

[0094] In this step, the master hand 210 enters the processing area 12 and places the pallet 410 on a table (not shown). The pallet 410 is held on the table by a clamp mechanism built into the table. The master hand 210 releases the first gripper 120A and exits the processing area 12.

[0095] 9 and 12, next, the control device 610 (robot control unit 620) controls the robot 21 so that the master hand 210 grips the third gripping portion 120C of the work hand 310 stored in the hand stocker 81.

[0096] In this step, the master hand 210 moves toward the hand stocker 81. The master hand 210 mounts the workpiece hand 310 on the robot 21 by gripping the third gripping portion 120C.

[0097] 9 and 13, next, the control device 610 (robot control unit 620) controls the robot 21 and the work hand 310 so that the work hand 310 grips the work W.

[0098] In this step, the workpiece hand 310 moves toward the workpiece stocker 71. The workpiece hand 310 grips the unmachined workpiece W.

[0099] Referring to Figures 9 and 14, next, the control device 610 (robot control unit 620) controls the robot 21 and the work hand 310 so that the work W grasped by the work hand 310 is held by the pallet 410 arranged in the processing area 12 of the machine tool 10.

[0100] In this step, the workpiece hand 310 enters the processing area 12 and places the workpiece W on the jig on the pallet 410. While the jig holds the workpiece W, the workpiece hand 310 releases the workpiece W. The workpiece hand 310 exits the processing area 12. Following this step, the machine tool 10 performs processing of the workpiece W in the processing area 12.

[0101] 9 and 15, next, the control device 610 (robot control unit 620) controls the robot 21 and the work hand 310 to store the machined workpiece W′ in the workpiece stocker 71.

[0102] In this step, the work hand 310 enters the processing area 12. The work hand 310 grips the processed work W', and the jig on the pallet 410 releases the work W'. The work hand 310 gripping the work W' leaves the processing area 12 and moves toward the work stocker 71. The work hand 310 places the work W' in the work stocker 71, and releases the work W'. Through the above steps, work processing using the work stocker 71 is completed.

[0103] 16 to 20 are top views showing steps of workpiece machining using the setup station, and correspond to FIG.

[0104] 2, the initial state is the same as in the workpiece machining using the workpiece stocker 71 described above.

[0105] 9 and 16, the control device 610 (robot control unit 620) controls the robot 21 so that the master hand 210 grips the first gripper 120A of the pallet 410 stored in the pallet stocker 31. The control device 610 (robot control unit 620) controls the robot 21 so that the pallet 410 gripped by the master hand 210 moves to the setup station 61.

[0106] In this step, the master hand 210 moves toward the setup station 61, and places the pallet 410 on a pallet placement table (not shown) installed in the setup station 61. The master hand 210 releases the first gripper 120A. The master hand 210 exits the setup station 61.

[0107] 9 and 17, next, an operator sets the workpiece W on the pallet 410. In this step, the unmachined workpiece W is held against the pallet 410 using a jig on the pallet 410.

[0108] 9 and 18, next, the control device 610 (robot control unit 620) controls the robot 21 so that the master hand 210 grips the first gripper 120A of the pallet 410 arranged in the setup station 61.

[0109] 9 and 19, next, the control device 610 (robot control unit 620) controls the robot 21 so that the pallet 410 grasped by the master hand 210 moves to the processing area 12. Following this step, the machine tool 10 executes processing of the workpiece W in the processing area 12.

[0110] 9 and 20, next, the control device 610 (robot control unit 620) controls the robot 21 so that the master hand 210 grips the first gripper 120A of the pallet 410 arranged in the processing area 12. The control device 610 (robot control unit 620) controls the robot 21 so that the pallet 410 gripped by the master hand 210 moves to the setup station 61. Following this step, the worker removes the machined workpiece W' from the jig on the pallet 410. Through the above steps, the workpiece processing using the setup station 61 is completed.

[0111] 21 to 23 are top views showing steps of inserting a pallet into a pallet stocker. Figures 21 to 23 correspond to Figure 2.

[0112] 9 and 21, in an initial state, no pallet 410 is stored in pallet stocker 31. An operator places pallet 410 on a pallet placement table (not shown) in setup station 61.

[0113] 9 and 22, the control device 610 (robot control unit 620) controls the robot 21 so that the master hand 210 grips the first gripper 120A of the pallet 410 arranged in the setup station 61. The control device 610 (robot control unit 620) controls the robot 21 so that the pallet 410 gripped by the master hand 210 moves to the pallet stocker 31.

[0114] 9 and 22, next, the control device 610 (robot control unit 620) controls the robot 21 to place the pallet 410 gripped by the master hand 210 on the shelf board 510.

[0115] By repeating the above steps, a plurality of pallets 410 can be loaded into the pallet stocker 31.

[0116] Yet another use of the robot 21 in the transport system 100 is to change the position of the shelf boards 510 in the pallet stocker 31. Referring to Fig. 7, the pallet stocker 31 has a multi-tiered shelf structure consisting of multiple floors, namely "1st", "2nd", "3rd", "4th" and "5th".

[0117] A support section 560(1-1) is provided on the lowest floor indicated as "1st," and a support section 560(5-1) is provided on the highest floor indicated as "5th." A shelf board 510 is disposed on each of the support sections 560, 560(1-1) and 560(5-1). The shelf board 510 supported by each of the support sections 560, 560(1-1) and 560(5-1), is of a fixed type that cannot be moved between the multiple support sections 560.

[0118] On the second floor from the bottom, indicated as "2nd," support parts 560(2-1) and 560(2-2) are provided with a gap between them. The robot 21 can move the shelf board 510 between the support parts 560(2-1) and 560(2-2).

[0119] On the middle floor indicated as "3rd", support parts 560(3-1), 560(3-2), and 560(3-3) are provided at intervals vertically. The robot 21 can move the shelf board 510 between the support parts 560(3-1), 560(3-2), and 560(3-3).

[0120] On the second floor from the top, indicated as "4th," support parts 560(4-1) and 560(4-2) are provided at a distance from each other above and below. The robot 21 can move the shelf board 510 between the support parts 560(4-1) and 560(4-2).

[0121] In the current arrangement of the shelf board 510, on the "2nd" floor, the shelf board 510 is supported by a support portion 560(2-1). On the "3rd" floor, the shelf board 510 is supported by a support portion 560(3-3). On the "4th" floor, the shelf board 510 is supported by a support portion 560(4-1).

[0122] 7 and 9, an operator performs an operation to change the position of shelf board 510 via display unit 670 consisting of a touch panel display, for example. Operation receiving unit 660 receives the operator's operation and outputs a signal corresponding to the operation to program analysis unit 622. The signal output to program analysis unit 622 includes a signal for identifying the position before movement (first support portion 560A) of shelf board 510 to be changed and the position after movement (second support portion 560B).

[0123] When the robot control unit 620 (program analysis unit 622) receives a command to change the position of the shelf board 510 from the first support part 560A to the second support part 560B among the multiple support parts 560, the robot control unit 620 (program analysis unit 622) controls the robot 21 to move the shelf board 510 from the first support part 560A to the second support part 560B while gripping the shelf board 510 with the master hand 210. As an example, when the support part 560(3-3) corresponds to the first support part 560A and the support part 560(3-1) corresponds to the second support part 560B, the shelf board 510 is transferred to the robot 21 and changed in position from the support part 560(3-3) to the support part 560(3-1).

[0124] By changing the position of the shelf boards 510 in this manner, the maximum height of the workpieces that can be placed on the pallet 410 on each of the "1st", "2nd", "3rd" and "4th" floors can be freely adjusted.

[0125] Next, there will be explained a teaching operation of the robot 21. Fig. 24 is a flow chart showing the overall flow of the teaching operation of the robot.

[0126] Referring to Figure 24, in order to enable the master hand 210 to grip the first gripping portion 120A of the pallet 410 stored in the pallet stocker 31, a teaching operation is performed to identify the position of the first gripping portion 120A of each pallet 410 stored in the pallet stocker 31.

[0127] The overall flow of the teaching work will be described below. First, an operator temporarily assembles the transport system 100 (S101).

[0128] In this step, an operator assembles the robot 21 onto the robot base 22 in the assembly factory of the conveying system 100, and installs the machine tool 10, pallet stocker 31, work stocker 71, hand stocker 81, setup station 61, etc. around the robot base 22.

[0129] Next, automatic teaching is executed by the robot 21 to generate a user coordinate system 901 for the pallet stocker 31 (S102).

[0130] The user coordinate system is a coordinate system that can be defined by the user separately from the coordinate system serving as the reference for the robot 21 (for example, a world coordinate system with the center of the robot base 22 as the origin). The coordinate axes consisting of the three orthogonal axes of the X-axis, Y-axis and Z-axis (see FIG. 7) described above correspond to the user coordinate system 901 defined for the pallet stocker 31.

[0131] Next, automatic teaching is performed by the robot 21 to set the position of the first gripper 120A of each pallet 410 in the user coordinate system 901 (S103). The position of the first gripper 120A set in this step is a specific position on the axis of the grip center of the first gripper 120A, and is also referred to below as the "grip position of the first gripper 120A."

[0132] After the automatic teaching is performed in steps S102 and S103, the conveyance system 100 is disassembled and shipped from the assembly factory to a user's factory or the like.

[0133] Next, an operator installs the transport system 100 (S104). In this step, the operator installs the transport system 100 in a user's factory or the like.

[0134] Next, the operator regenerates the user coordinate system 901 for the pallet stocker 31 by manual teaching (S105).

[0135] Since the transport system 100 has gone through a process of dismantling and reassembling since the user coordinate system 901 was generated in the previous step S102, the positional relationship between the robot base 22 and the pallet stocker 31 changes, and the attitude of the pallet stocker 31 changes. In this step, the user coordinate system 901 corresponding to the pallet stocker 31 after installation is regenerated.

[0136] Next, the grip position of first gripping unit 120A is corrected so as to correspond to user coordinate system 901 regenerated in step S105 (S106). Since the user coordinate system 901 generated in step S102 and the user coordinate system 901 regenerated in step S105 differ in the position of the origin and the directions of the X-axis, Y-axis, and Z-axis, the grip position of first gripping unit 120A is corrected so as to correspond to the regenerated user coordinate system 901.

[0137] Next, the structure of the pallet stocker 31 used in the automatic teaching of steps S102 and S103 in FIG. 24 will be described.

[0138] Fig. 25 is a front view showing the pallet stocker during automatic teaching. Referring to Fig. 25, a plurality of reference spheres 911 are attached to the pallet stocker 31 during the automatic teaching of steps S102 and S103 in Fig. 24.

[0139] The reference sphere 911 includes a spherical portion. The multiple reference spheres 911 are provided at positions spaced apart from each other. The multiple reference spheres 911 are provided in the same plane (X-axis-Y-axis plane). The multiple reference spheres 911 are provided in front of the pallet stocker 31 in the Z-axis direction.

[0140] The multiple reference spheres 911 include a first reference sphere 911A, a second reference sphere 911B, and a third reference sphere 911C. The first reference sphere 911A and the second reference sphere 911B are provided at a distance from each other in the X-axis direction. The first reference sphere 911A and the second reference sphere 911B are attached to both ends of the support section 560(1-1) in the X-axis direction, respectively. The third reference sphere 911C is provided at a distance from the second reference sphere 911B in the Y-axis direction. The third reference sphere 911C is attached to one end of the support section 560(5-1) in the X-axis direction.

[0141] The reference sphere 911 is provided so as to be detachable from the pallet stocker 31. The reference sphere 911 is provided so as to be detachable from the support portion 560. The multiple reference spheres 911 may be removed from the pallet stocker 31 after the automatic teaching is completed.

[0142] During the automatic teaching of steps S102 and S103 in FIG. 24, second gripper 120B in FIG. 3 is not attached to shelf board 510, and pallet 410 in FIG.

[0143] The shelf board 510 is provided with a plurality of reference holes 921 (921p, 921q, 921r).

[0144] The reference hole 921 is provided in the horizontal frame 531. The reference hole 921 penetrates the horizontal frame 531 in the Z-axis direction and forms a circular opening parallel to the X-axis-Y-axis plane. The reference hole 921 is provided in the front surface of the pallet stocker 31 (horizontal frame 531) in the Z-axis direction. The multiple reference holes 921 are provided at intervals from each other in the Z-axis direction. The multiple reference holes 921 are provided at equal intervals in the Z-axis direction.

[0145] FIG. 26 is a front view showing the positional relationship between the reference hole and the first gripping portion of the pallet stored in the work stocker.

[0146] 25 and 26, when the pallet 410 is placed on the shelf board 510, a plurality of tapered cones provided on the bottom surface of the pallet 410 are received by a plurality of tapered cone receiving portions 525 provided on the shelf board 510. With this configuration, the positional relationship between the reference hole 921 provided on the shelf board 510 and the first gripping portion 120A of the pallet 410 placed on the shelf board 510 is mechanically determined.

[0147] More specifically, when viewed in the Z-axis direction, the grip position of first gripping part 120A is located directly above the center of the opening of reference hole 921. The X-axis coordinate of the center of the opening of reference hole 921 and the X-axis coordinate of the grip position of first gripping part 120A are the same, and the Y-axis coordinate of the grip position of first gripping part 120A is the Y-axis coordinate of the center of the opening of reference hole 921 plus a constant value Δy. The Z-axis coordinate of the center of the opening of reference hole 921 may be the same as the Z-axis coordinate of the grip position of first gripping part 120A, or may be shifted by a constant value.

[0148] In each shelf board 510, reference hole 921p, reference hole 921q, and reference hole 921r are provided corresponding to pallet support portion 520p, pallet support portion 520q, and pallet support portion 520r, respectively. The reference hole 921p and the first gripping portion 120A of the pallet 410 supported by the pallet support portion 520p satisfy the above positional relationship, the reference hole 921q and the first gripping portion 120A of the pallet 410 supported by the pallet support portion 520q satisfy the above positional relationship, and the reference hole 921r and the first gripping portion 120A of the pallet 410 supported by the pallet support portion 520r satisfy the above positional relationship.

[0149] The first reference sphere 911A, the second reference sphere 911B and the third reference sphere 911C are targets for measurement by the touch probe 720 held by the robot 21 during the automatic teaching in step S102 in Fig. 24. The multiple reference holes 921 are targets for measurement by the touch probe 720 held by the robot 21 during the automatic teaching in step S103 in Fig. 24.

[0150] Fig. 27 is a block diagram showing a control system for automatic teaching, Fig. 28 is a perspective view showing automatic teaching for generating a user coordinate system, and Fig. 29 is a diagram showing a user coordinate system generating screen on the display unit.

[0151] 27 to 29, the robot control unit 620 further has a pallet stocker positional relationship storage unit 627. The pallet stocker positional relationship storage unit 627 stores the positional relationship between the center position of the reference hole 921 (the center position of the opening surface of the reference hole 921) and the grip position of the first gripper 120A.

[0152] The program storage unit 621 stores various operation programs 641 for commanding the operation of the robot 21. The operation programs 641 include an operation program 641Q for automatic teaching. The operation program 641Q for automatic teaching commands the operation of the robot 21 during automatic teaching.

[0153] The program analysis unit 622 receives a command to start automatic teaching by a signal from the operation reception unit 660, and reads out an operation program 641Q from the program storage unit 621. The program analysis unit 622 analyzes the operation program 641Q, extracts commands related to movement, and transmits the commands to the axis control unit 623. The program analysis unit 622 analyzes the operation program 641Q, extracts commands related to the operation of the master hand 210, and transmits the commands to the hand control unit 624.

[0154] The axis control unit 623 controls the multiple drive servo motors 23 in response to commands from the program analysis unit 622. The hand control unit 624 controls the master hand 210 in response to commands from the program analysis unit 622.

[0155] The configuration for automatic teaching (generation of a user coordinate system) in step S102 in FIG. 24 will be described below.

[0156] The robot control unit 620 operates the robot 21 to detect the center positions of the first reference sphere 911A, the second reference sphere 911B, and the third reference sphere 911C in the pallet stocker 31, and generates a user coordinate system 901 in the pallet stocker 31 based on the center positions of the first reference sphere 911A, the second reference sphere 911B, and the third reference sphere 911C.

[0157] 28, the robot control unit 620 operates the robot 21 so that the teaching hand 710 held by the master hand 210 approaches the first reference sphere 911A. The robot control unit 620 operates the robot 21 so that the contactor 720g of the touch probe 720 contacts multiple points (for example, four points) spaced apart from each other on the spherical surface of the first reference sphere 911A. The touch probe 720 converts position information of each point on the spherical surface of the first reference sphere 911A into an electrical signal, and outputs the signal to the robot control unit 620.

[0158] Similarly, the robot control unit 620 operates the robot 21 so that the contactor 720g of the touch probe 720 comes into contact with a plurality of points spaced apart from one another on the spherical surface of the second reference sphere 911B. The touch probe 720 converts position information of each point on the spherical surface of the second reference sphere 911B into an electrical signal, and outputs the signal to the robot control unit 620. The robot control unit 620 operates the robot 21 so that the contactor 720g of the touch probe 720 comes into contact with a plurality of points spaced apart from one another on the spherical surface of the third reference sphere 911C. The touch probe 720 converts position information of each point on the spherical surface of the third reference sphere 911C into an electrical signal, and outputs the signal to the robot control unit 620.

[0159] The robot control unit 620 further includes a user coordinate system generation unit 637. The user coordinate system generation unit 637 calculates the center position of the first reference sphere 911A, the center position of the second reference sphere 911B, and the center position of the third reference sphere 911C based on a signal from the touch probe 720.

[0160] The user coordinate system generation unit 637 generates a user coordinate system 901 having the center position of the first reference sphere 911A as its origin, an X-axis extending from the center position of the first reference sphere 911A toward the center position of the second reference sphere 911B, a Y-axis extending from the center position of the first reference sphere 911A perpendicular to the X-axis and parallel to a plane connecting the center positions of the first reference sphere 911A, the second reference sphere 911B, and the third reference sphere 911C, and a Z-axis extending from the center position of the first reference sphere 911A in a direction perpendicular to the X-axis and Y-axis.

[0161] The user coordinate system generating unit 637 stores the generated user coordinate system 901 for the pallet stocker 31 in the parameter storage unit 625 .

[0162] The control device 610 further includes a display control unit 650. The display control unit 650 controls the screen display on the display unit 670.

[0163] The operator performs an operation to start the user coordinate system generation mode through the display unit 670 consisting of a touch panel display. The operation acceptance unit 660 accepts the operator's operation and outputs a signal corresponding to the operation to the display control unit 650. As a result, the display control unit 650 causes the display unit 670 to display a user coordinate system generation screen 671.

[0164] As shown in FIG. 29, a user coordinate system generation screen 671 has a position information display section 672 and a pallet stocker image section 673.

[0165] The position information display portion 672 displays position information of the centers of the first reference sphere 911 A, the second reference sphere 911 B, and the third reference sphere 911 C, and position information of the origin of the user coordinate system 901 .

[0166] The "Origin" item relates to position information of the first reference sphere 911A. The center of the first reference sphere 911A is set at the origin of the user coordinate system 901. The "Point 1" item relates to position information of the second reference sphere 911B, and the "Point 2" item relates to position information of the third reference sphere 911C. The "measurement" item displays position information (coordinates and hand posture) of the center of each reference sphere 911 measured by the touch probe 720. The "designed" item displays designed position information of the center of each reference sphere 911.

[0167] The "User frame N" item displays the position information of the origin of the user coordinate system 901 generated by the user coordinate system generating unit 637 using the coordinates of the world coordinate system.

[0168] The pallet stocker image portion 673 displays an image of the pallet stocker 31 as viewed in the Z-axis direction, as well as the positions of the first reference sphere 911A, the second reference sphere 911B, and the third reference sphere 911C in that image.

[0169] The user coordinate system generation screen 671 further has a first operation unit 681 and a second operation unit 682. The first operation unit 681 is configured to start measurement of the first reference sphere 911A, the second reference sphere 911B, and the third reference sphere 911C by the touch probe 720 when operated by the operator. The second operation unit 682 is configured to store the generated user coordinate system 901 in the parameter storage unit 625 when operated by the operator.

[0170] Next, a configuration for automatic teaching (setting of grip position) in step S103 in FIG. 24 will be described.

[0171] Fig. 30 is a perspective view showing the automatic teaching for setting the grip position, and Fig. 31 is a diagram showing a grip position setting screen on the display unit.

[0172] 27, 30 and 31, in step S103 following step S102 in FIG. 24, the robot control unit 620 operates the robot 21 to detect the center position of the reference hole 921 in the shelf board 510, and calculates the grip position of the first gripper 120A in the user coordinate system 901 based on the detected center position of the reference hole 921 and the positional relationship between the reference hole 921 and the first gripper 120A when the pallet 410 is placed on the shelf board 510.

[0173] 30, the robot control unit 620 operates the robot 21 so that the teaching hand 710 held by the master hand 210 approaches the reference hole 921. The robot control unit 620 operates the robot 21 so that the contactor 720g of the touch probe 720 contacts multiple points (for example, four points) spaced apart from one another on the opening edge of the reference hole 921. The touch probe 720 converts position information of each point on the opening edge of the reference hole 921 into an electrical signal, and outputs the signal to the robot control unit 620.

[0174] The robot control unit 620 further includes a grip position calculation unit 636. The grip position calculation unit 636 calculates the center position of each reference hole 921 (the center position of the opening surface of the reference hole 921) based on a signal from the touch probe 720.

[0175] The grip position calculation unit 636 reads out the positional relationship between the center position of the reference hole 921 and the grip position of the first gripper 120A from the pallet stocker positional relationship storage unit 627. The grip position calculation unit 636 calculates the grip position of the first gripper 120A based on the calculated center position of the reference hole 921 and the positional relationship read out from the pallet stocker positional relationship storage unit 627.

[0176] The grip position calculation unit 636 stores the calculated grip position of the first gripping unit 120A in the parameter storage unit 625.

[0177] The robot control unit 620 performs the above-mentioned automatic teaching for the reference holes 921p, 921q, and 921r on the shelf boards 510 supported by each of the supports 560, i.e., support portion 560(1-1), support portion 560(2-1), support portion 560(3-3), support portion 560(4-1), and support portion 560(5-1).

[0178] The robot control unit 620 moves the shelf board 510 from the support portion 560(2-1) to the support portion 560(2-2), and performs the above-mentioned automatic teaching for the reference holes 921p, 921q, and 921r on the shelf board 510 supported by the support portion 560(2-2).

[0179] The robot control unit 620 moves the shelf board 510 from support portion 560(3-3) to each of support portions 560, support portion 560(3-1) and support portion 560(3-2), and performs the above-mentioned automatic teaching for reference hole 921p, reference hole 921q, and reference hole 921r on the shelf board 510 supported by each of support portions 560, support portion 560(3-1) and support portion 560(3-2).

[0180] The robot control unit 620 moves the shelf board 510 from the support portion 560(4-1) to the support portion 560(4-2), and performs the above-mentioned automatic teaching for the reference holes 921p, 921q, and 921r on the shelf board 510 supported by the support portion 560(4-2).

[0181] 27, the operator performs an operation to activate the grip position setting mode through display unit 670, which is a touch panel display. Operation accepting unit 660 accepts the operator's operation and outputs a signal corresponding to the operation to display control unit 650. As a result, display control unit 650 causes display unit 670 to display a grip position setting screen 675.

[0182] As shown in FIG. 31, a grip position setting screen 675 has a position information display section 677, a pallet stocker image section 678, and a progress display section 676.

[0183] The position information display portion 677 displays position information of the opening center of each reference hole 921 and information on the grip position of each first gripping portion 120A.

[0184] 31 representatively shows information relating to shelf board 510 supported by support portion 560(1-1) and pallet 410 placed on shelf board 510. Items "1-1-p," "1-1-q," and "1-1-r" correspond to pallet support portion 520p, pallet support portion 520q, and pallet support portion 520r, respectively.

[0185] The "measurement" item displays position information (coordinates and hand posture) of the opening center of each reference hole 921 measured by the touch probe 720. The "pallet grip point" item displays position information of the grip position of each first gripper 120A calculated by the grip position calculation unit 636. The "adjustment" item is configured to allow an adjustment value to be input when the grip position of the first gripper 120A calculated by the grip position calculation unit 636 is to be adjusted.

[0186] The pallet stocker image portion 678 displays an image of the pallet stocker 31 when viewed in the Z-axis direction, as well as the positions of the multiple reference holes 921 and the multiple first grippers 120A in that image.

[0187] The progress display section 676 displays the progress of setting the grip position of the first gripping portion 120A. When the setting of the grip position of the first gripping portion 120A is completed, a check mark is added. In the progress display section 676, a check mark is further added to the support portion 560 on which the shelf board 510 is arranged, among the multiple support portions 560.

[0188] The grip position setting screen 675 further has a third operation unit 683 and a fourth operation unit 684. The third operation unit 683 is configured to be operated by an operator to start measurement of the reference hole 921 by the touch probe 720. The fourth operation unit 684 is configured to be operated by an operator to store the calculated grip position of the first gripping unit 120A in the parameter storage unit 625.

[0189] Next, there will be described the flow of steps in the automatic teaching of the robot 21. Fig. 32 is a flowchart showing the flow of steps in the automatic teaching for generating a user coordinate system.

[0190] 27 to 29 and 32, as a preparation for automatic teaching of the robot 21, a teaching hand 710 is attached to the robot 21 (S201). In this step, the master hand 210 grasps the fourth gripping portion 120D of the teaching hand 710 in FIG.

[0191] Next, when an operation for starting the user coordinate system generation mode is performed by the operator, the control device 610 (display control unit 650) causes the display unit 670 to display a user coordinate system generation screen 671 (S202).

[0192] Next, the control device 610 (robot control unit 620) receives a command to start automatic teaching (S203).

[0193] In this step, the operator operates the first operation unit 681 on the user coordinate system generating screen 671, and the operation acceptance unit 660 accepts the operation. The operation acceptance unit 660 outputs a start signal for measurement of the first reference sphere 911A, the second reference sphere 911B, and the third reference sphere 911C by the touch probe 720 to the program analysis unit 622.

[0194] Next, the control device 610 (robot control unit 620) controls the robot 21 so that the measurement of the first reference sphere 911A is performed by the touch probe 720 (S204). Next, the control device 610 (robot control unit 620) calculates the center position of the first reference sphere 911A (S205). In this step, the user coordinate system generation unit 637 calculates the center position of the first reference sphere 911A based on the signal from the touch probe 720, and outputs the calculated center position of the first reference sphere 911A to the display control unit 650. Next, the control device 610 (display control unit 650) displays position information of the center of the first reference sphere 911A on the position information display unit 672 on the user coordinate system generation screen 671 (S206).

[0195] Next, the control device 610 executes the above steps S204 to S206 for the second reference sphere 911B. Next, the control device 610 executes the above steps S204 to S206 for the third reference sphere 911C.

[0196] Next, the control device 610 (robot control unit 620) calculates the user coordinate system 901 in the pallet stocker 31 (S207).

[0197] In this step, the user coordinate system generation unit 637 calculates a user coordinate system 901 having the center position of the first reference sphere 911A as its origin based on the center position of the first reference sphere 911A, the center position of the second reference sphere 911B, and the center position of the third reference sphere 911C. The user coordinate system generation unit 637 outputs the calculated user coordinate system 901 to the display control unit 650.

[0198] Next, the control device 610 (display control unit 650) causes the position information of the origin of the user coordinate system 901 to be displayed in the position information display unit 672 on the user coordinate system generating screen 671 (S206).

[0199] Next, the control device 610 (robot control unit 620) receives a command to store the user coordinate system 901 (S209). In this step, the operator operates the second operation unit 682 on the user coordinate system generation screen 671, and the operation acceptance unit 660 accepts the operation. The operation acceptance unit 660 outputs a storage signal for the user coordinate system 901 to the user coordinate system generation unit 637.

[0200] Next, the control device 610 (robot control unit 620) stores the user coordinate system 901 in the pallet stocker 31 in the parameter storage unit 625 (S210). Through the above steps, the automatic teaching for generating the user coordinate system 901 is completed.

[0201] FIG. 33 is a flow chart showing the flow of steps of automatic teaching for setting the grip position.

[0202] 27, 30, 31 and 33, when an operation is performed by the operator to activate the grip position setting mode, the control device 610 (display control unit 650) causes the display unit 670 to display a grip position setting screen 675 (S301).

[0203] Next, the control device 610 (robot control unit 620) receives a command to start automatic teaching (S302).

[0204] In this step, the operator operates the third operation unit 683 on the grip position setting screen 675, and the operation is accepted by the operation acceptance unit 660. The operation acceptance unit 660 outputs a start signal for measurement of the reference hole 921 by the touch probe 720 to the program analysis unit 622.

[0205] Next, the control device 610 (robot control unit 620) controls the robot 21 so that the measurement of the reference hole 921 is performed by the touch probe 720 (S303). Next, the control device 610 (robot control unit 620) calculates the center position of the reference hole 921 (S304). In this step, the grip position calculation unit 636 calculates the center position of the reference hole 921 based on the signal from the touch probe 720, and outputs the calculated center position of the reference hole 921 to the display control unit 650. Next, the control device 610 (display control unit 650) displays position information of the opening center of the reference hole 921 on the position information display unit 677 on the grip position setting screen 675 (S305).

[0206] Next, the control device 610 (robot control unit 620) calculates the grip position of the first gripper 120A on the pallet 410 (S306). In this step, the grip position calculation unit 636 calculates the grip position of the first gripper 120A based on the positional relationship between the center position of the reference hole 921 calculated in step S305, the center position of the reference hole 921 read from the pallet stocker positional relationship storage unit 627, and the grip position of the first gripper 120A. The grip position calculation unit 636 outputs the calculated grip position of the first gripper 120A to the display control unit 650.

[0207] Next, the control device 610 (display control unit 650) displays information on the grip position of the first gripping portion 120A in the position information display unit 677 on the grip position setting screen 675. The control device 610 (display control unit 650) displays a check mark in the field corresponding to the calculated first gripping portion 120A in the progress display unit 676 on the grip position setting screen 675 (S307).

[0208] The control device 610 executes the above steps S303 to S307 for the reference hole 921p, the reference hole 921q, and the reference hole 921r in the shelf board 510 supported by each of the supports 560, i.e., support portion 560(1-1), support portion 560(2-1), support portion 560(3-3), support portion 560(4-1), and support portion 560(5-1).

[0209] Next, the control device 610 (robot control unit 620) controls the robot 21 to move the shelf board 510 from the support portion 560(2-1) to the support portion 560(2-2) (S308). Next, the control device 610 executes the above steps S303 to S307 for the reference hole 921p, the reference hole 921q, and the reference hole 921r in the shelf board 510 supported by the support portion 560(2-2).

[0210] Similarly, the control device 610 (robot control unit 620) controls the robot 21 to move the shelf board 510 from support portion 560(3-3) to each of the supports 560, support portion 560(3-1) and support portion 560(3-2) (S308). Next, the control device 610 executes the above steps S303 to S307 for the reference hole 921p, the reference hole 921q, and the reference hole 921r in the shelf board 510 supported by each of the supports 560, support portion 560(3-1) and support portion 560(3-2).

[0211] The control device 610 (robot control unit 620) controls the robot 21 to move the shelf board 510 from the support unit 560(4-1) to the support unit 560(4-2) (S308). Next, the control device 610 executes the above steps S303 to S307 for the reference hole 921p, the reference hole 921q, and the reference hole 921r in the shelf board 510 supported by the support unit 560(4-2). Through the above steps, check marks are added to the columns of all the first gripping units 120A in the progress display unit 676, indicating that the grip position setting is complete.

[0212] Next, the control device 610 (robot control unit 620) receives a command to store the grip position of the first gripper 120A (S309). In this step, the worker operates the fourth operation unit 684 on the grip position setting screen 675, and the operation acceptance unit 660 accepts the operation. The operation acceptance unit 660 outputs a grip position storage signal to the user coordinate system generation unit 637.

[0213] Next, the control device 610 (robot control unit 620) stores the grip position of the first gripper 120A in the parameter storage unit 625 (S210). Through the above steps, the automatic teaching for setting the grip position of the first gripper 120A is completed.

[0214] Next, a description will be given of the manual teaching in step S105 in Fig. 24. Fig. 34 is a side view showing the manual teaching.

[0215] 34, the pallet stocker 31 has a plurality of jigs 970 (970A, 970B, 970C). Each of the jigs 970 has a pin portion 971. The pin portion 971 extends in the Z-axis direction.

[0216] The multiple jigs 970 are detachably provided to the pallet stocker 31. In step S105 in Fig. 24, the first jig 970A and the second jig 970B are attached to both ends of the support part 560 (1-1) in the X-axis direction, respectively, instead of the first reference sphere 911A and the second reference sphere 911B in Fig. 7. The third jig 970C is attached to one end of the support part 560 (5-1) in the X-axis direction, instead of the third reference sphere 911C in Fig. 7.

[0217] 24, the operator attaches a hand-side jig 960 having a pin portion 961 to the robot 21. The operator operates the robot 21 using a teaching pendant so that the tip of the pin portion 961 contacts the tips of the pin portions 971 of the first jig 970A, the second jig 970B, and the third jig 970C in that order. This identifies the position of the tip of the pin portion 971 of each jig 970.

[0218] The user coordinate system generation unit 637 regenerates the user coordinate system 901 in the pallet stocker 31 based on the positions of the tips of the pin portions 971 of the first jig 970A, the second jig 970B, and the third jig 970C. The user coordinate system generation unit 637 stores the regenerated user coordinate system 901 in the pallet stocker 31 in the parameter storage unit 625.

[0219] 24, grip position calculation unit 636 corrects the grip position of first gripping unit 120A so as to correspond to the regenerated user coordinate system 901. Grip position calculation unit 636 stores the corrected grip position of first gripping unit 120A in parameter storage unit 625.

[0220] To summarize the configuration of the transport system 100 in the embodiment of the present invention described above, the transport system 100 in this embodiment has a shelf board 510 on which the pallet 410 can be placed, a pallet stocker 31 for storing the pallet 410, a master hand 210 as a hand capable of gripping a first gripper 120A as a gripper of the pallet 410, a robot 21 that transports the pallet 410, and a robot control unit 620 that controls the robot 21. The robot control unit 620 operates the robot 21 to detect the center positions of a first reference sphere 911A, a second reference sphere 911B, and a third reference sphere 911C as the positions of three parts of the pallet stocker 31 that are spaced apart from each other, and generates a user coordinate system 901 in the pallet stocker 31 based on the detected center positions of the first reference sphere 911A, the second reference sphere 911B, and the third reference sphere 911C. The robot control unit 620 operates the robot 21 to detect the center position of the reference hole 921 as the position of a specific part of the shelf board 510, and calculates the position of the first gripping portion 120A in the user coordinate system 901 based on the detected center position of the reference hole 921, the center position of the reference hole 921 when the pallet 410 is placed on the shelf board 510, and the positional relationship of the first gripping portion 120A.

[0221] According to such a configuration, the labor required for teaching the robot 21 can be reduced compared to a case where the pallet 410 is placed on the shelf board 510 and the position of the first gripper 120A of the pallet 410 is directly detected.

[0222] Furthermore, when the user coordinate system 901 in the pallet stocker 31 is regenerated, the robot control unit 620 corrects the position of the first gripper 120A so that it corresponds to the regenerated user coordinate system 901.

[0223] According to this configuration, when the transport system 100 is temporarily assembled in an assembly factory or the like, a user coordinate system 901 in the pallet stocker 31 is generated, and the position of the first gripper 120A in the user coordinate system 901 is calculated, thereby identifying the position of the first gripper 120A in the system of the pallet stocker 31 in advance. Thereafter, when the transport system 100 is installed in a user's factory or the like, the user coordinate system 901 of the pallet stocker 31 corresponding to the assembled state at the time of installation is regenerated, and the position of the first gripper 120A is corrected so as to correspond to the regenerated user coordinate system 901. This makes it possible to reduce the labor required for teaching work when installing the transport system 100.

[0224] The pallet stocker 31 further has a plurality of support parts 560 arranged at intervals in the vertical direction, each capable of supporting a shelf board 510. The robot control part 620 receives a command to change the position of the shelf board 510 from a first support part 560A to a second support part 560B among the plurality of support parts 560, and controls the robot 21 in response to the command to move the shelf board 510 from the first support part 560A to the second support part 560B while holding the shelf board 510 with the master hand 210.

[0225] According to this configuration, the position of the shelf board 510 is variable, so that the number of positions of the first gripping part 120A to be identified increases. Therefore, the effect of reducing the labor required for the teaching work of the robot 21 is more effectively achieved.

[0226] In addition, the conveying system 100 further includes a display unit 670 and a display control unit 650 that causes the display unit 670 to display the center position of the first reference sphere 911A as the position of the origin in the user coordinate system 901 generated by the robot control unit 620, and the position of the first gripping unit 120A calculated by the robot control unit 620.

[0227] According to this configuration, the operator can check the result of position detection by automatic teaching on the display unit.

[0228] In addition, the automatic teaching method in this embodiment includes the steps of operating the robot 21 to detect the central positions of a first reference sphere 911A, a second reference sphere 911B and a third reference sphere 911C as the positions of three mutually separated parts of the pallet stocker 31, and generating a user coordinate system 901 in the pallet stocker 31 based on the detected central positions of the first reference sphere 911A, the second reference sphere 911B and the third reference sphere 911C (S201 to S210), and the steps of operating the robot 21 to detect the central position of a reference hole 921 as the position of a specific part of the shelf board 510, and calculating the position of the first gripper 120A in the user coordinate system 901 based on the detected central position of the reference hole 921, the central position of the reference hole 921 when the pallet 410 is placed on the shelf board 510, and the positional relationship of the first gripper 120A (S301 to S310).

[0229] With this configuration, the labor required for teaching the robot 21 can be reduced.

[0230] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0231] 10, 10S, 10T machine tool, 12 machining area, 14 cover body, 16 opening, 18 operation panel, 21 robot, 22 robot base, 23 drive servo motor, 26 base unit, 27 first arm, 28 second arm, 29 hand attachment unit, 31, 31S, 31T pallet stocker, 51 transport operation panel, 56, 56h, 56i, 56j, 56k fence, 61, 61S, 61T setup station, 71 work stocker, 81 hand stocker, 100 transport system, 101 swivel center axis, 102, 103, 105 rotation center axis, 104, 106 rotation center axis, 113 space, 120 gripper, 120A first gripper, 120B second gripper, 120C Third gripping portion, 120D Fourth gripping portion, 121 Groove portion, 126, 231 Central axis, 210 Master hand, 220 Clamping mechanism, 221 Grip insertion hole, 226 Piston, 227 Protrusion portion, 230 Sensor, 310 Work hand, 320 Grip jaw, 330 Piston cylinder, 340 Servo motor, 410 Pallet, 510 Shelf, 520, 520p, 520q, 520r Pallet support portion, 525 Taper cone receiving portion, 531 Horizontal frame, 532 Vertical frame, 533 Pin hole, 550 Frame body, 551 Column, 560 Support portion, 560A First support portion, 560B Second support portion, 561 Plate, 610 Control device, 620 Robot control portion, 621 Program memory portion, 622 Program analysis portion, 623 Axis control section, 624 Hand control section, 625 Parameter storage section, 627 Pallet stocker positional relationship storage section, 630 Input / output device, 636 Grip position calculation section, 637 User coordinate system generation section, 641, 641Q Operation program, 650 Display control section, 660 Operation acceptance section, 670 Display section, 671 User coordinate system generation screen, 672, 677 Position information display section, 673, 678 Pallet stocker image section, 675 Grip position setting screen, 676 Progress display section, 681 First operation section, 682 Second operation section, 683 Third operation section, 684 Fourth operation section, 710 Teaching hand, 720 Touch probe, 720g Contactor, 901 User coordinate system, 911 Reference sphere, 911A First reference sphere, 911B Second reference sphere, 911C Third reference sphere, 921,921p,921q,921r reference hole, 960 hand side jig, 961, 971 pin part, 970 jig, 970A first jig, 970B second jig, 970C third jig.

Claims

1. A robot control device for controlling a robot having a hand capable of gripping a gripping portion of a pallet, for transporting the pallet to a pallet stocker having a shelf board on which the pallet can be placed and a plurality of support parts arranged at intervals in a vertical direction, each of which can support the shelf board, operating the robot so as to detect positions of three mutually separated portions of the pallet stocker, and generating a user coordinate system in the pallet stocker based on the detected positions of the three portions; operating the robot to detect a position of a specific portion of the shelf board, and calculating a position of the gripping part in the user coordinate system based on the detected position of the specific portion and a positional relationship between the specific portion and the gripping part in a state in which the pallet is placed on the shelf board; A robot control device that receives a command to reposition the shelf board from a first support part to a second support part among the plurality of support parts, and controls the robot in response to the command to move the shelf board from the first support part to the second support part while grasping the shelf board with the hand.

2. 2. The robot control device according to claim 1, wherein, when the user coordinate system in the pallet stocker is regenerated, the position of the gripper is corrected so as to correspond to the regenerated user coordinate system.

3. The robot control device according to claim 1 , further comprising: a display unit configured to display the generated position of the origin in the user coordinate system and the calculated position of the gripping portion.

4. A method for controlling a robot having a hand capable of gripping a gripping portion of a pallet, for transporting the pallet to a pallet stocker having a shelf on which the pallet can be placed and a plurality of support portions arranged at intervals in a vertical direction, each of which can support the shelf portion, comprising: operating the robot to detect positions of three mutually separated portions of the pallet stocker, and generating a user coordinate system in the pallet stocker based on the detected positions of the three portions; operating the robot to detect a position of a specific portion of the shelf board, and calculating a position of the gripper in the user coordinate system based on the detected position of the specific portion and a positional relationship between the specific portion and the gripper in a state in which the pallet is placed on the shelf board; a step of receiving a command to reposition the shelf board from a first support part to a second support part among the plurality of support parts, and controlling the robot in response to the command to move the shelf board from the first support part to the second support part while grasping the shelf board with the hand.

Images