Robot control device and robot control method

Abstract

Provided are a conveying system and an automatic teaching method capable of reducing the labor required for the teaching work of a robot. 【Solution means】The conveying system includes a robot control unit (620). The robot control unit (620) operates the robot so as to detect the positions of three mutually separated parts (911A, 911B, 911C) of the 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 so as to detect the position of a specific part (921) of the shelf board (510), and calculates the position of the gripping part (120A) in the user coordinate system based on the detected position and the positional relationship between the specific part (921) and the gripping part (120A) of the pallet (410) in a state where the pallet is placed on the shelf board (510).

Description

Technical Field

[0001] This invention relates to a robot control device and Robot control method the like.

Background Art

[0002] For example, Japanese Patent Application Laid-Open No. 2017-102825 (Patent Document 1) discloses a composite system including a machine tool having a work fixing jig that can move integrally with a table, a work stocker that stores workpieces, and 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

Summary of the Invention

Problems to be Solved by the Invention

[0004] As disclosed in the above Patent Document 1, a conveyance system that conveys various objects to be conveyed using a robot is known. In such a conveyance system, a teaching operation for teaching the robot to move is required, and it is demanded to reduce the labor required for this teaching operation.

[0005] An object of this invention is to provide a conveyance system and an automatic teaching method capable of reducing the labor required for the teaching operation of a robot.

Means for Solving the Problems

[0006] The transport system according to the present invention includes a shelf board on which a pallet can be placed, a pallet stocker for storing the pallet, a robot having a hand capable of gripping a gripping portion of the pallet, and a robot controller for controlling the robot. The robot controller operates the robot so as to detect the positions of three mutually separated portions of the pallet stocker, and generates a user coordinate system in the pallet stocker based on the detected positions of the three portions. The robot controller operates the robot so as to detect the position of a specific portion of the shelf board, and calculates the position of the gripping portion in the user coordinate system based on the detected position of the specific portion and the positional relationship between the specific portion and the gripping portion in a state where the pallet is placed on the shelf board.

[0007] The automatic teaching method according to the present invention is an automatic teaching method in a transport system including a shelf board on which a pallet can be placed, a pallet stocker for storing the pallet, a robot having a hand capable of gripping a gripping portion of the pallet, and a robot for transporting the pallet. The automatic teaching method includes the steps of operating the robot so as to detect the 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; and operating the robot so as to detect the position of a specific portion of the shelf board, and calculating the position of the gripping portion in the user coordinate system based on the detected position of the specific portion and the positional relationship between the specific portion and the gripping portion in a state where the pallet is placed on the shelf board.

Advantages of the Invention

[0008] According to the present invention, it is possible to provide a transport system and an automatic teaching method capable of reducing the labor required for the teaching work of the robot.

Brief Description of the Drawings

[0009]

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Embodiments for Carrying Out the Invention

[0010] Embodiments of the present invention will be described with reference to the drawings. In the drawings referred to below, the same or corresponding members are denoted by the same reference numerals.

[0011] FIG. 1 is a top view showing a conveying system according to an embodiment of the present invention. FIG. 2 is a top view showing a simplified conveying system in FIG. 1.

[0012] Referring to FIGS. 1 and 2, the conveying system 100 in the present embodiment includes 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 includes a base portion 26, a first arm 27, a second arm 28, a hand attachment portion 29, and a master hand 210.

[0014] The robot base 22 is a support base that supports the robot 21 and is fixed to the floor surface of a factory or the like. The robot base 22 is made of metal. The base portion 26 is connected to the robot base 22 so as to be rotatable about a turning center axis 101. The turning center axis 101 is a virtual straight line corresponding to the turning center of the robot 21 and extends in the vertical direction.

[0015] The first arm 27 is attached to the base portion 26. The first arm 27 is rotatable about a rotation center axis 102 disposed at an attachment portion (joint portion) of the first arm 27 with respect to the base portion 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 an attachment portion (joint portion) of the second arm 28 with respect to the first arm 27, and the hand attachment portion 29 can be rotated about a rotation center axis 104 along the second arm 28. The hand attachment portion 29 is attached to the second arm 28. The hand attachment portion 29 is rotatable about a rotation center axis 105 disposed at an attachment portion (joint portion) of the hand attachment portion 29 with respect to the second arm 28, and the master hand 210 can be rotated about a rotation center axis 106 along the hand attachment portion 29.

[0016] The master hand 210 is attached to the hand attachment portion 29 as an end effector. The master hand 210 is attached to be rotatable about the rotation center axis 105 with respect to the second arm 28. The master hand 210 is attached to the second arm 28 via the hand attachment portion 29. The second arm 28 is attached to be rotatable about the rotation center axis 103 with respect to the first arm 27.

[0017] The robot 21 further includes 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 plurality of axes (swivel 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 FIGS. 9 and 27 to be described later).

[0018] In FIG. 1, the area where the master hand 210 moves in the transfer system 100 (the operating area of the master hand 210) is shown by the two-dot chain line 111. Also, the maximum area where the master hand 210 can move is shown by the two-dot chain line 112 that extends in an arc shape around the turning center axis 101.

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

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

[0021] Note that the robot in the present invention is not limited to the above-described six-axis articulated robot. For example, it may be a robot (gantry loader) capable of moving an object to be transferred in three axial directions orthogonal to each other. Also, the machine tool, pallet stocker, work stocker, hand stocker, and setup station may be arranged side by side in a straight line.

[0022] The machine tool 10 is a machining center that performs workpiece machining 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 workpiece machining are automated by numerical control by a computer.

[0023] The machine tool 10 may be a composite machining machine having a turning function using a fixed tool and a milling function using a rotating tool, or may be an AM / SM hybrid machining machine capable of additive manufacturing of the workpiece and subtractive manufacturing of the workpiece. The machine tools 10S and 10T may be of the same type as each other or may be of different types from each other.

[0024] The machine tool 10 has a cover body 14. The cover body 14 forms the appearance of the machine tool 10 and partitions and forms a machining area 12. The machining area 12 is a space where workpiece machining is performed, and is sealed by the cover body 14 so that foreign matters such as chips or cutting oil accompanying workpiece machining do not leak to the outside of the machining area.

[0025] An opening 16 is provided in the cover body 14. The robot 21 conveys a workpiece W or a conveyance object such as a pallet 410 to the machining area 12 through the opening 16. A door or shutter capable of opening and closing operations is provided in the opening 16.

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

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

[0028] The machine tools 10S and 10T are provided at positions facing each other with the robot base 22 interposed therebetween. The machine tools 10S and 10T are provided at angular positions shifted by 180° in the circumferential direction about the turning center axis 101.

[0029] The pallet stocker 31 is a device for storing the pallet 410. The pallet stocker 31 is provided between the machine tools 10S and 10T in the circumferential direction about the turning center axis 101. The pallet stockers 31S and 31T are provided adjacent to each other in the circumferential direction about the turning center axis 101.

[0030] The work stocker 71 is a device for storing the work W. The work stocker 71 has a shelf structure on which the work 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, which will be described later. The hand stocker 81 has a shelf structure on which various hands can be placed.

[0031] The work stocker 71 and the hand stocker 81 are provided between the machine tools 10S and 10T in the circumferential direction about the turning center axis 101. The work stocker 71 and the hand stocker 81 are provided at positions facing the pallet stocker 31 (31S, 31T) with the robot base 22 interposed therebetween. The work stocker 71 and the hand stocker 81 are provided one above the other.

[0032] The setup station 61 is mainly a device for performing the attachment / detachment work of the work W to / from the pallet 410. A pallet mounting table (not shown) on which the pallet 410 can be mounted is installed in the setup station 61. The setup station 61 is provided between the work stocker 71 and the hand stocker 81 and the machine tool 10 in the circumferential direction about the turning center axis 101. The setup station 61 is provided adjacent to the work stocker 71 and the hand stocker 81 in the circumferential direction about the turning center axis 101.

[0033] The setup stations 61S and 61T are provided on both sides of the workpiece stocker 71 and the hand stocker 81 in the circumferential direction centered on the turning center axis 101.

[0034] Note that the number of each device of the machine tool 10, the pallet stocker 31, the workpiece stocker 71, the hand stocker 81, and the setup station 61 provided in the transport system 100 is not particularly limited.

[0035] The transport system 100 further has a plurality of fences 56 (56h, 56i, 56j, 56k). The fences 56 rise from the floor surface 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 arranged 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 workpiece stocker 71, the hand stocker 81, and the setup station 61 (61S, 61T). The operating area of the master hand 210 indicated by the two-dot chain line 111 is included in the space 113.

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

[0038] The conveying system 100 further includes an operation panel 51 for conveying. The operation panel 51 for conveying includes a control device 610 that controls the operation of the robot 21, a display unit 670 for displaying various information related to the conveyance by the robot 21, and an operation unit that receives various operations for the robot 21 (see FIGS. 9 and 27 to be described later). In the present embodiment, the display unit 670 is configured by a touch panel display operable by the operator and undertakes part of the functions of the operation unit. The operation unit may be composed of various push buttons that can be pressed, numeric keys for inputting numbers, or dials, etc.

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

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

[0041] Referring to FIGS. 3 to 6, the master hand 210 has a clamp mechanism 220. The clamp mechanism 220 is operably configured between a clamped state for holding the gripping part 120 and an unclamped state for releasing the gripping part 120.

[0042] As shown in FIGS. 4 to 6, the gripping part 120 has a grip shape centered on the central axis 126. A groove part 121 is provided in the gripping part 120. The groove part 121 is recessed from the outer peripheral surface of the gripping part 120 and has a groove shape that circulates around the central axis 126.

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

[0044] The clamp mechanism 220 consists of a cylinder piston. The clamp mechanism 220 has a pair of pistons 226. The pair of pistons 226 are orthogonal to the central axis 126 and extend in a shaft shape along a central axis 231 that intersects the grip insertion hole 221. The pair of pistons 226 face each other with a space therebetween in the axial direction of the central axis 231. The pair of pistons 226 are slidably supported in the axial direction of the central axis 126. A protrusion 227 that can engage with the groove part 121 is provided at the tip of each piston 226.

[0045] When the master hand 210 grips the gripping part 120, the master hand 210 is positioned so that the clamp mechanism 220 faces the gripping part 120. By linearly moving the master hand 210 in a direction approaching the gripping part 120, the gripping part 120 is inserted into the grip insertion hole 221. By supplying air pressure or the like and sliding the pair of pistons 226 in a direction approaching each other, the clamp mechanism 220 is operated 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 groove part 121.

[0046] When the master hand 210 releases the gripping part 120, the clamping mechanism 220 is operated from the clamped state to the unclamped state by sliding a pair of pistons 226 in a direction away from each other. As a result, the protrusions 227 of the pair of pistons 226 exit from the grip insertion holes 221 and come out of the groove part 121. By linearly moving the master hand 210 in a direction away from the gripping part 120, the gripping part 120 is removed from the grip insertion holes 221.

[0047] As shown in FIG. 5, the conveying system 100 further includes a sensor 230. The sensor 230 is a sensor capable of detecting the presence or absence of an object, and as an example, it is 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 insertion / withdrawal direction of the gripping part 120 with respect to the master hand 210.

[0049] Referring to FIG. 3, the conveying system 100 further includes a pallet 410 for holding a workpiece. The conveying system 100 has a plurality of pallets 410.

[0050] The pallet 410 is made of a metal plate material and has a substantially rectangular shape when viewed from above. The table provided in the machine tool 10 incorporates a clamping mechanism for gripping the pallet 410. Fixtures such as jigs or clamping devices are attached to the pallet 410, and the workpiece is held on the pallet 410 via the fixture.

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

[0052] When the master hand 210 grips the first gripping portion 120A, 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 range surrounded by the two-dot chain line VIII in FIG. 7.

[0054] In FIGS. 7 and 8, and in other figures showing the pallet stocker 31, the X-axis, Y-axis, and Z-axis, which are the coordinate axes in the pallet stocker 31, are shown. The X-axis extends in the horizontal direction corresponding to the width direction (left-right direction) of the pallet stocker 31, the Y-axis extends in the vertical direction, and the Z-axis extends in the horizontal direction corresponding to the depth direction (front-back direction) of the pallet stocker 31. The X-axis, Y-axis, and Z-axis are three mutually orthogonal axes.

[0055] Referring to FIGS. 3, 7, and 8, the pallet stocker 31 has a frame body 550, a plurality of support portions 560, and a plurality of shelf plates 510.

[0056] The frame body 550 forms a rectangular parallelepiped-shaped frame. The frame body 550 forms a rectangular parallelepiped-shaped frame in which each direction in the X-axis direction and the Y-axis direction is the longitudinal direction and the Z-axis direction is the short side direction. The frame body 550 has four columns 551. The four columns 551 are arranged at the four corners of the frame body 550 in a top view. Each column 551 extends in the Y-axis direction (vertical direction).

[0057] The support portion 560 is configured to be able to support the shelf plate 510. The plurality of support portions 560 are arranged at intervals 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 at intervals in the X-axis direction. The plate 561 has an L-shaped cross-sectional shape when cut by the X-axis - Y-axis plane and extends in the Z-axis direction. Both ends of the plate 561 in the Z-axis direction are respectively connected to two columns 551 arranged in the Z-axis direction.

[0059] The shelf board 510 is configured to be able to place the pallet 410. The shelf board 510 has a rectangular shape in a top view, with the X-axis direction being the longitudinal direction, the Z-axis direction being the short side direction, and the Y-axis direction being the thickness direction, and has a plate shape.

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

[0061] As shown in FIGS. 7 and 8, the shelf board 510 is supported by the support portion 560. The pair of vertical frames 532 are placed on the pair of plates 561. The pair of vertical frames 532 receive 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 the 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. With such a configuration, displacement of the shelf board 510 with respect to the support portion 560 is prevented.

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

[0064] Each pallet support portion 520 is configured to be able to support the pallet 410. Each pallet support portion 520 is composed of four tapered cone receivers 525 that are arranged at intervals in the X-axis direction and the Z-axis direction. The tapered cone receiver 525 is provided on the horizontal frame 531. The tapered cone receiver 525 protrudes upward from the top surface of the horizontal frame 531. The tapered cone receiver 525 has a concave shape capable of receiving a tapered cone provided on the bottom surface of the pallet 410.

[0065] The pallet support portions 520p, 520q, and 520r are arranged in the X-axis direction in the order listed.

[0066] The shelf board 510 is compatible with the placement of pallets 410 of different sizes. For example, the shelf board 510 is compatible with the placement of a pallet 410 of a size of 400 mm × 400 mm and the placement of a pallet 410 of a size of 500 mm × 500 mm. When the pallet 410 is of a size of 400 mm × 400 mm, three pallets 410 can be placed on the shelf board 510 using the pallet support portions 520p, 520q, and 520r. When the pallet 410 is of a size of 500 mm × 500 mm, two pallets 410 can be placed on the shelf board 510 using the pallet support portions 520p and 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 above-described gripping portion 120 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 (taper cone receiving portion 525). The second gripping portion 120B is detachably provided with respect to the shelf board 510.

[0068] When the master hand 210 grips the second gripping portion 120B, the robot 21 can transport the shelf board 510. The robot 21 executes the replacement of the position of the shelf board 510 among a plurality of support portions 560 in the pallet stocker 31. The replacement of the position of the shelf board 510 using this robot 21 will be described in detail later.

[0069] Referring to FIG. 3, the work hand 310 is configured to be able to grip the work W. The work hand 310 has a pair of gripping claws 320. The pair of gripping claws 320 are opposed to each other with a space 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 claws 320 and an unclamped state in which the pair of gripping claws 320 release the work W. By sliding the pair of gripping claws 320 in a direction approaching each other, the work hand 310 operates from the unclamped state to the clamped state. By sliding the pair of gripping claws 320 in a direction away from each other, the work hand 310 operates from the clamped state to the unclamped state.

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

[0072] The workpiece hand 310 further has a third gripping part 120C. The third gripping part 120C corresponds to the above-described gripping part 120 and is configured to be grippable by the master hand 210. The third gripping part 120C has a grip shape extending in a direction orthogonal to the sliding direction of the pair of gripping claws 320. The third gripping part 120C is detachably provided with respect to the workpiece hand 310.

[0073] By the master hand 210 gripping the third gripping part 120C, the workpiece hand 310 can be attached to the robot 21. The robot 21 can convey 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 the teaching operation of the robot 21 using the touch probe 720.

[0075] The teaching hand 710 further has a fourth gripping part 120D. The fourth gripping part 120D corresponds to the above-described gripping part 120 and is configured to be grippable by the master hand 210. The touch probe 720 has a pin-shaped contact 720g that contacts the measurement object. The fourth gripping part 120D has a grip shape extending in a direction orthogonal to the direction in which the contact 720g extends in a pin shape. The fourth gripping part 120D is detachably provided with respect to the teaching hand 710.

[0076] By the master hand 210 gripping the fourth gripping part 120D, the teaching hand 710 can be attached to the robot 21.

[0077] The first gripping part 120A, the second gripping part 120B, the third gripping part 120C, and the fourth gripping part 120D have the same grip shape as each other. The master hand 210 is configured to be able to selectively grip any one of the gripping parts 120, namely, the first gripping part 120A, the second gripping part 120B, the third gripping part 120C, and the fourth gripping part 120D.

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

[0079] Each component of the control device 610 is realized by hardware including an arithmetic unit such as a CPU (Central Processing Unit) and various computer processors, a storage device such as a memory or a storage, and a wired or wireless communication line connecting them, and software stored in the storage device and supplying processing instructions to the arithmetic unit. The computer program constituting the software may be composed of a device driver, an operating system, various application programs located in upper layers thereof, or a library providing common functions to these programs. The computer program may be recorded on a computer-readable storage medium or 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 includes an operation reception unit 660 and a robot control unit 620. The operation reception unit 660 receives an operator's operation through a display unit 670 (operation unit) composed of, for example, a touch panel display. The operation reception unit 660 outputs a signal corresponding to the operator's operation 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 includes 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 operations 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 stop 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 arc movement, and speed commands that define the movement speed. The operation programs 641 are input via the input / output device 630 connected to the robot control unit 620 and stored in the program storage unit 621.

[0084] The operation programs 641 are described in a language called SLIM (Standard Language for Industrial Manipulators), for example. The specific positions and orientations (postures) in each position command included in the operation programs 641 are obtained by operating the robot 21 through a manual operation called a teaching operation. As the robot 21 operates during the teaching operation, the rotational angle positions of the respective 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 stored in the program storage unit 621, which is the operation program 641 to be executed, in response to a signal from the operation reception 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 operations, and transmits the commands to the hand control unit 624.

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

[0087] Specifically, the axis control unit 623 reads parameters corresponding to each position command from the parameter storage unit 625, 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 arc movement), and further, a rotation command (control signal) for each drive servo motor 23 is generated so as to move at the commanded speed, and is transmitted to each drive servo motor 23. The plurality of drive servo motors 23 move the master hand 210 to the commanded position by having a drive current corresponding to the rotation command from the axis control unit 623 supplied thereto.

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

[0089] Subsequently, a specific example of the usage form of the robot 21 in the transfer system 100 will be described. FIGS. 10 to 15 are top views showing the steps of workpiece processing using a work stocker. FIGS. 10 to 15 correspond to FIG. 2.

[0090] Referring to FIG. 2, in the initial state, a plurality of pallets 410 are stored in the pallet stocker 31. Fixtures (not shown) such as ikeals or clamping devices are mounted on the pallet 410. The workpiece stocker 71 stores unprocessed workpieces W. The hand stocker 81 stores a plurality of workpiece hands 310 and a teaching hand 710. The workpiece hand 310 may have a pair of gripping claws 320 that differ in shape or size from each other among the plurality of workpiece hands 310.

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

[0092] In this step, the master hand 210 moves toward the pallet stocker 31 and is positioned to face the first gripping portion 120A of the pallet 410 in the Z-axis direction. When 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. When the master hand 210 moves upward, the pallet 410 is lifted from the shelf board 510.

[0093] Referring to FIGS. 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 machining area 12 and places the pallet 410 on a table (not shown). The pallet 410 is held on the table by a clamping mechanism built into the table. The master hand 210 releases the first gripping portion 120A and exits the machining area 12.

[0095] Referring to FIGS. 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. By gripping the third gripping portion 120C with the master hand 210, the work hand 310 is attached to the robot 21.

[0097] Referring to FIGS. 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 work hand 310 moves toward the work stocker 71. The work hand 310 grips the unprocessed work W.

[0099] Referring to FIGS. 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 gripped by the work hand 310 is held by the pallet 410 disposed in the machining area 12 of the machine tool 10.

[0100] In this step, the work hand 310 enters the machining area 12 and places the work W on the jig on the pallet 410. The jig holds the work W, and the work hand 310 releases the work W. The work hand 310 exits the machining area 12. Subsequently to this step, the machine tool 10 executes machining of the work W in the machining area 12.

[0101] Referring to FIGS. 9 and 15, next, the control device 610 (robot control unit 620) controls the robot 21 and the work hand 310 so that the machined work W' is stored in the work 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 that has gripped the work W' exits the processing area 12 and moves toward the work stocker 71. The work hand 310 places the work W' on the work stocker 71 and releases the work W'. Through the above steps, the work processing using the work stocker 71 is completed.

[0103] Figures 16 to 20 are top views showing the steps of work processing using the setup station. Figures 16 to 20 correspond to Figure 2.

[0104] Referring to Figure 2, the initial state is the same as the work processing using the above work stocker 71.

[0105] Referring to Figures 9 and 16, the control device 610 (robot control unit 620) controls the robot 21 so that the master hand 210 grips the first gripping portion 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 mounting table (not shown) installed at the setup station 61. The master hand 210 releases the first gripping portion 120A. The master hand 210 exits the setup station 61.

[0107] Referring to Figures 9 and 17, next, the operator sets the work W on the pallet 410. In this step, the unprocessed work W is held on the pallet 410 using the jig on the pallet 410.

[0108] Referring to FIGS. 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 gripping portion 120A of the pallet 410 disposed at the setup station 61.

[0109] Referring to FIGS. 9 and 19, 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. Subsequently to this step, the machine tool 10 executes machining of the workpiece W in the machining area 12.

[0110] Referring to FIGS. 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 gripping portion 120A of the pallet 410 disposed in the machining 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. Subsequently to this step, the operator removes the machined workpiece W' from the jig on the pallet 410. Through the above steps, the machining of the workpiece using the setup station 61 is completed.

[0111] FIGS. 21 to 23 are top views showing the steps of loading a pallet onto the pallet stocker. FIGS. 21 to 23 correspond to FIG. 2.

[0112] Referring to FIGS. 9 and 21, in the initial state, the pallet 410 is not stored in the pallet stocker 31. The operator places the pallet 410 on the pallet mounting table (not shown) at the setup station 61.

[0113] Referring to FIGS. 9 and 22, the control device 610 (robot control unit 620) controls the robot 21 such that the master hand 210 grips the first gripping portion 120A of the pallet 410 disposed at the setup station 61. The control device 610 (robot control unit 620) controls the robot 21 such that the pallet 410 gripped by the master hand 210 moves to the pallet stocker 31.

[0114] Referring to FIGS. 9 and 22, next, the control device 610 (robot control unit 620) controls the robot 21 such that the pallet 410 gripped by the master hand 210 is placed 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] As yet another usage form of the robot 21 in the transport system 100, there is a replacement of the shelf board 510 in the pallet stocker 31. Referring to FIG. 7, the pallet stocker 31 has a multi-stage shelf structure including a plurality of floors of "1st", "2nd", "3rd", "4th", and "5th".

[0117] A support portion 560(1-1) is provided on the lowermost floor indicated as "1st", and a support portion 560(5-1) is provided on the uppermost floor indicated as "5th". Shelf boards 510 are arranged on each of the support portions 560 of the support portion 560(1-1) and the support portion 560(5-1). The shelf boards 510 supported by each of the support portions 560 of the support portion 560(1-1) and the support portion 560(5-1) are fixed types that cannot be replaced between the plurality of support portions 560.

[0118] On the second floor from the bottom indicated as "2nd", support portions 560(2-1) and 560(2-2) are provided at intervals in the vertical direction. The robot 21 can move the shelf board 510 between the support portion 560(2-1) and the support portion 560(2-2).

[0119] On the middle floor indicated as "3rd", support portions 560(3 - 1), 560(3 - 2), and 560(3 - 3) are provided with a vertical gap therebetween. The robot 21 can move the shelf board 510 between the support portions 560(3 - 1), 560(3 - 2), and 560(3 - 3).

[0120] On the second floor from the top indicated as "4th", support portions 560(4 - 1) and 560(4 - 2) are provided with a vertical gap therebetween. The robot 21 can move the shelf board 510 between the support portions 560(4 - 1) and 560(4 - 2).

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

[0122] Referring to FIGS. 7 and 9, an operator performs an operation for replacing the position of the shelf board 510, for example, through a display portion 670 composed of a touch panel display. The operation reception portion 660 receives the operator's operation and outputs a signal corresponding to the operation to the program analysis portion 622. The signal output to the program analysis portion 622 includes a signal for specifying the position (first support portion 560A) before the movement of the shelf board 510 to be replaced and the position (second support portion 560B) after the movement.

[0123] When the robot control unit 620 (program analysis unit 622) receives a command to replace the shelf board 510 from the first support unit 560A to the second support unit 560B among the plurality of support units 560, it controls the robot 21 to move the shelf board 510 from the first support unit 560A to the second support unit 560B while gripping the shelf board 510 with the master hand 210. As an example, when the support unit 560(3 - 3) corresponds to the first support unit 560A and the support unit 560(3 - 1) corresponds to the second support unit 560B, the shelf board 510 is relocated from the support unit 560(3 - 3) to the support unit 560(3 - 1) by being conveyed by the robot 21.

[0124] By performing the replacement of the shelf board 510 in this way, 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] Subsequently, the teaching operation of the robot 21 will be described. FIG. 24 is a flowchart showing the overall flow of the teaching operation of the robot.

[0126] Referring to FIG. 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] To explain the overall flow of the teaching operation, first, the operator assembles the temporary structure of the conveyance system 100 (S101).

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

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

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

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

[0132] After the automatic teaching in steps S102 and S103 is performed, the transport system 100 is disassembled and shipped from the assembly factory to the 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 the 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] Due to the process of disassembling and reassembling the transport system 100 from the generation of the user coordinate system 901 in the previous step S102, the positional relationship between the robot base 22 and the pallet stocker 31 may change, or the posture of the pallet stocker 31 may change. In this step, the user coordinate system 901 corresponding to the pallet stocker 31 after installation is regenerated.

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

[0137] Subsequently, the structure of the pallet stocker 31 used for the automatic teaching in 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 mounted on the pallet stocker 31 during the automatic teaching in steps S102 and S103 in FIG. 24.

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

[0140] The plurality of reference spheres 911 includes 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 intervals in the X-axis direction. The first reference sphere 911A and the second reference sphere 911B are respectively attached to both ends of the support portion 560(1 - 1) in the X-axis direction. The third reference sphere 911C is provided at an interval from the second reference sphere 911B in the Y-axis direction. The third reference sphere 911C is attached to one end of the support portion 560(5 - 1) in the X-axis direction.

[0141] The reference ball 911 is detachably provided with respect to the pallet stocker 31. The reference ball 911 is detachably provided with respect to the support portion 560. After the automatic teaching is completed, the plurality of reference balls 911 may be removed from the pallet stocker 31.

[0142] During the automatic teaching of steps S102 and S103 in FIG. 24, the second gripping portion 120B in FIG. 3 is not mounted on the shelf board 510, and the pallet 410 in FIG. 3 is not placed on the shelf board 510.

[0143] A plurality of reference holes 921 (921p, 921q, 921r) are provided in the shelf board 510.

[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 on the front surface of the pallet stocker 31 (horizontal frame 531) in the Z-axis direction. The plurality of reference holes 921 are provided at intervals in the Z-axis direction. The plurality of 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] Referring to FIGS. 25 and 26, in a state where 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 respectively received in a plurality of tapered cone receiving portions 525 provided on the shelf board 510. With such a configuration, the positional relationship between the reference hole 921 provided in 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 the first gripping portion 120A is located directly above the opening center of the reference hole 921. The X-axis coordinate of the opening center of the reference hole 921 and the X-axis coordinate of the grip position of the first gripping portion 120A are the same, and the Y-axis coordinate of the grip position of the first gripping portion 120A is a value obtained by adding a constant value Δy to the Y-axis coordinate of the opening center of the reference hole 921. The Z-axis coordinate of the opening center of the reference hole 921 may be the same as the Z-axis coordinate of the grip position of the first gripping portion 120A, or may be a value deviated by a constant value.

[0148] In each shelf board 510, the reference holes 921p, 921q, and 921r are respectively provided corresponding to the pallet support portions 520p, 520q, and 520r. 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 the objects of measurement by the touch probe 720 held by the robot 21 during the automatic teaching in the step of S102 in FIG. 24. The plurality of reference holes 921 are the objects of measurement by the touch probe 720 held by the robot 21 during the automatic teaching in the step of 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 the state of automatic teaching for generating a user coordinate system. FIG. 29 is a diagram showing a screen for generating a user coordinate system on the display unit.

[0151] Referring to FIGS. 27 to 29, the robot control unit 620 further includes a pallet stocker position relationship memory unit 627. The pallet stocker position relationship memory 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 gripping unit 120A.

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

[0153] The program analysis unit 622 receives a command to start automatic teaching based on a signal from the operation reception unit 660, reads out the operation program 641Q from the program storage unit 621, 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 a plurality of drive servo motors 23 according to commands from the program analysis unit 622. The hand control unit 624 controls the master hand 210 according to commands from the program analysis unit 622.

[0155] Hereinafter, the configuration for automatic teaching (generation of the user coordinate system) in step S102 in FIG. 24 will be described.

[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] More specifically, as shown in FIG. 28, the robot control unit 620 operates the robot 21 so that the teaching hand 710 gripped by the master hand 210 approaches the first reference sphere 911A. The robot control unit 620 operates the robot 21 so that the contact 720g of the touch probe 720 contacts a plurality of points (for example, four points) on the spherical surface of the first reference sphere 911A that are separated from each other. The touch probe 720 converts the 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 contact 720g of the touch probe 720 contacts a plurality of points on the spherical surface of the second reference sphere 911B that are separated from each other. The touch probe 720 converts the 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 contact 720g of the touch probe 720 contacts a plurality of points on the spherical surface of the third reference sphere 911C that are separated from each other. The touch probe 720 converts the 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 positions of the first reference sphere 911A, the second reference sphere 911B, and the third reference sphere 911C based on the signals from the touch probe 720.

[0160] The user coordinate system generation unit 637 generates a user coordinate system 901 with the center position of the first reference sphere 911A as the 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 that is orthogonal to the X-axis and parallel to the 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 orthogonal to each of the X-axis and the Y-axis.

[0161] The user coordinate system generation unit 637 stores the user coordinate system 901 in the generated 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 activate the user coordinate system generation mode through the display unit 670 composed of a touch panel display. The operation reception unit 660 receives the operator's operation and outputs a signal corresponding to the operation to the display control unit 650. Thereby, the display control unit 650 causes the user coordinate system generation screen 671 to be displayed on the display unit 670.

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

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

[0166] The item "Origin" relates to the 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 item "Point 1" relates to the position information of the second reference sphere 911B, and the item "Point 2" relates to the position information of the third reference sphere 911C. The item "measurement" displays the position information (coordinates and hand posture) of the centers of the respective reference spheres 911 measured by the touch probe 720. The item "designed" displays the designed position information of the centers of the respective reference spheres 911.

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

[0168] The pallet stocker image unit 673 displays the positions of the first reference sphere 911A, the second reference sphere 911B, and the third reference sphere 911C in the image, together with the image of the pallet stocker 31 when viewed in the Z-axis direction.

[0169] The user coordinate system generation screen 671 further includes a first operation unit 681 and a second operation unit 682. The first operation unit 681 is configured to start the 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] Subsequently, the configuration for the automatic teaching (setting of the grip position) in step S103 in FIG. 24 will be described.

[0171] FIG. 30 is a perspective view showing the state of automatic teaching for setting the grip position. FIG. 31 is a view showing the grip position setting screen on the display unit.

[0172] Referring to FIGS. 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 on the shelf board 510, and based on the detected center position of the reference hole 921 and the positional relationship between the reference hole 921 and the first gripping portion 120A in the state where the pallet 410 is placed on the shelf board 510, calculates the grip position of the first gripping portion 120A in the user coordinate system 901.

[0173] More specifically, as shown in FIG. 30, the robot control unit 620 operates the robot 21 so that the teaching hand 710 gripped by the master hand 210 approaches the reference hole 921. The robot control unit 620 operates the robot 21 so that the contact 720g of the touch probe 720 contacts a plurality of points (for example, four points) on the opening edge of the reference hole 921 that are separated from each other. The touch probe 720 converts the 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 the 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 gripping portion 120A from the pallet stocker position relationship storage unit 627. The grip position calculation unit 636 calculates the grip position of the first gripping portion 120A based on the calculated center position of the reference hole 921 and the positional relationship read out from the pallet stocker position relationship storage unit 627.

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

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

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

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

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

[0181] As shown in FIG. 27, the operator performs an operation for activating the grip position setting mode through the display unit 670 composed of a touch panel display. The operation reception unit 660 receives the operator's operation and outputs a signal corresponding to the operation to the display control unit 650. Thereby, the display control unit 650 causes the display unit 670 to display the grip position setting screen 675.

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

[0183] The position information display unit 677 displays the position information of the opening centers of the respective reference holes 921 and the information on the grip positions of the respective first gripping portions 120A.

[0184] In FIG. 31, typically, information regarding the shelf board 510 supported by the support portion 560(1-1) and the pallet 410 placed on the shelf board 510 is shown. The items of "1-1-p", "1-1-q", and "1-1-r" respectively correspond to the pallet support portions 520p, 520q, and 520r.

[0185] The item of "measurement" displays the position information (coordinates and hand posture) of the opening centers of the respective reference holes 921 measured by the touch probe 720. The item of "pallet grip point" displays the position information of the grip positions of the respective first gripping portions 120A calculated by the grip position calculation unit 636. The item of "adjustment" is configured to enable input of the adjustment value when it is desired to adjust the grip position of the first gripping portion 120A calculated by the grip position calculation unit 636.

[0186] The pallet stocker image unit 678 displays the image of the pallet stocker 31 when viewed in the Z-axis direction, together with the positions of the plurality of reference holes 921 and the plurality of first gripping portions 120A in the image.

[0187] The progress display unit 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 attached. In the progress display unit 676, further, a check mark is attached to the support portion 560 on which the shelf board 510 is arranged among the plurality of support portions 560.

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

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

[0190] Referring to FIGS. 27 to 29 and FIG. 32, as a preparatory step for the automatic teaching of the robot 21, a teaching hand 710 is attached to the robot 21 (S201). In this step, the master hand 210 grips the fourth gripping unit 120D of the teaching hand 710 in FIG. 3.

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

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

[0193] In this step, the operator operates the first operation unit 681 on the user coordinate system generation screen 671, and the operation reception unit 660 receives the operation. The operation reception unit 660 outputs a start signal for the 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 first reference sphere 911A is measured 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) causes the position information display unit 672 on the user coordinate system generation screen 671 to display the position information of the center of the first reference sphere 911A (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 with the center position of the first reference sphere 911A as the origin based on the center positions of the first reference sphere 911A, the second reference sphere 911B, and 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 display unit 672 on the user coordinate system generation screen 671 to display the position information of the origin of the user coordinate system 901 (S206).

[0199] Next, the control device 610 (robot control unit 620) receives a storage command for the user coordinate system 901 (S209). In this step, an operator operates the second operation unit 682 on the user coordinate system generation screen 671, and the operation reception unit 660 receives the operation. The operation reception 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 flowchart showing the flow of steps of automatic teaching for setting the grip position.

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

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

[0204] In this step, an operator operates the third operation unit 683 on the grip position setting screen 675, and the operation reception unit 660 receives the operation. The operation reception unit 660 outputs a start signal for measuring 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 reference hole 921 is measured 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) causes the position information display unit 677 on the grip position setting screen 675 to display the position information of the opening center of the reference hole 921 (S305).

[0206] Next, the control device 610 (robot control unit 620) calculates the grip position of the first gripping unit 120A on the pallet 410 (S306). In this step, the grip position calculation unit 636 calculates the grip position of the first gripping unit 120A based on 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 position relationship storage unit 627, and the positional relationship of the grip position of the first gripping unit 120A. The grip position calculation unit 636 outputs the calculated grip position of the first gripping unit 120A to the display control unit 650.

[0207] Next, the control device 610 (display control unit 650) causes the position information display unit 677 on the grip position setting screen 675 to display the information on the grip position of the first gripping unit 120A. The control device 610 (display control unit 650) causes a check mark to be displayed in the column corresponding to the calculated first gripping unit 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 holes 921p, 921q, and 921r in the shelf board 510 supported by each of the support parts 560, namely, the support part 560(1-1), the support part 560(2-1), the support part 560(3-3), the support part 560(4-1), and the support part 560(5-1).

[0209] Next, the control device 610 (robot control unit 620) controls the robot 21 so that the shelf board 510 moves from the support part 560(2-1) to the support part 560(2-2) (S308). Next, the control device 610 executes the steps of S303 to S307 described above with respect to the reference holes 921p, 921q, and 921r in the shelf board 510 supported by the support part 560(2-2).

[0210] Similarly, the control device 610 (robot control unit 620) controls the robot 21 so that the shelf board 510 moves from the support part 560(3-3) to each of the support parts 560 of the support part 560(3-1) and the support part 560(3-2) (S308). Next, the control device 610 executes the steps of S303 to S307 described above with respect to the reference holes 921p, 921q, and 921r in the shelf board 510 supported by each of the support parts 560 of the support part 560(3-1) and the support part 560(3-2).

[0211] The control device 610 (robot control unit 620) controls the robot 21 so that the shelf board 510 moves from the support part 560(4-1) to the support part 560(4-2) (S308). Next, the control device 610 executes the steps of S303 to S307 described above with respect to the reference holes 921p, 921q, and 921r in the shelf board 510 supported by the support part 560(4-2). By the above steps, a check mark indicating the completion of the grip position setting is attached to all the columns of the first gripping part 120A in the progress display part 676.

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

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

[0214] Subsequently, the manual teaching of the step S105 in FIG. 24 will be described. FIG. 34 is a side view showing the state of manual teaching.

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

[0216] The plurality of jigs 970 are detachably provided with respect to the pallet stocker 31. In the step S105 in FIG. 24, the first jig 970A and the second jig 970B are respectively attached to both ends of the support portion 560(1-1) in the X-axis direction, replacing 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 portion 560(5-1) in the X-axis direction, replacing the third reference sphere 911C in FIG. 7.

[0217] During the manual teaching of the step S105 in FIG. 24, the operator attaches the hand-side jig 960 having the pin portion 961 to the robot 21. The operator operates the robot 21 using the teaching pendant so that the tip of the pin portion 961 sequentially contacts the tips of the pin portions 971 of the first jig 970A, the second jig 970B, and the third jig 970C. Thereby, the positions of the tips of the pin portions 971 of the respective jigs 970 are specified.

[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 tip ends 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] In step S106 in FIG. 24, the grip position calculation unit 636 corrects the grip position of the first gripping portion 120A so as to correspond to the regenerated user coordinate system 901. The grip position calculation unit 636 stores the corrected grip position of the first gripping portion 120A in the parameter storage unit 625.

[0220] Summarizing the configuration of the transport system 100 in the embodiment of the present invention described above, the transport system 100 in the present 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 that can grip the first gripping portion 120A as a gripping portion of the pallet 410, a robot 21 for transporting the pallet 410, and a robot control unit 620 for controlling the robot 21. The robot control unit 620 operates the robot 21 so as to detect the center positions of the first reference sphere 911A, the second reference sphere 911B, and the third reference sphere 911C as the positions of three mutually separated portions of the pallet stocker 31, and generates the 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 so as to detect the center position of the reference hole 921 as the position of a specific portion 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 in the state where 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 the teaching operation of the robot 21 can be reduced as compared with the case where the pallet 410 is placed on the shelf board 510 and the position of the first gripping portion 120A of the pallet 410 is directly detected.

[0222] Further, when the robot control unit 620 regenerates the user coordinate system 901 in the pallet stocker 31, the position of the first gripping portion 120A is corrected so as to correspond to the regenerated user coordinate system 901.

[0223] According to such a configuration, at the time of temporary assembly of the conveyance system 100 in an assembly factory or the like, the user coordinate system 901 in the pallet stocker 31 is generated, and the position of the first gripping portion 120A in the user coordinate system 901 is calculated, thereby previously specifying the position of the first gripping portion 120A within the system of the pallet stocker 31. Then, when the user installs the conveyance system 100 in a 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 gripping portion 120A is corrected so as to correspond to the regenerated user coordinate system 901. Thereby, the labor required for the teaching operation at the time of installation of the conveyance system 100 can be reduced.

[0224] Further, the pallet stocker 31 further has a plurality of support portions 560 that can each support the shelf board 510 and are arranged at intervals in the vertical direction. The robot control unit 620 receives a command to replace the position of the shelf board 510 from the first support portion 560A to the second support portion 560B among the plurality of support portions 560, and in response to the command, controls the robot 21 to move the shelf board 510 from the first support portion 560A to the second support portion 560B while gripping the shelf board 510 with the master hand 210.

[0225] According to such a configuration, since the position of the shelf board 510 is variable, the number of positions of the first gripping portion 120A to be specified increases. Therefore, the effect of reducing the labor required for the teaching operation of the robot 21 is more effectively achieved.

[0226] Further, the conveyance system 100 further includes a display unit 670, 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 such a configuration, an operator can confirm the result of position detection by automatic teaching through the display unit.

[0228] In addition, the automatic teaching method in the present embodiment operates the robot 21 so as to detect the center positions of the first reference sphere 911A, the second reference sphere 911B, and the third reference sphere 911C as the positions of three mutually separated parts of the pallet stocker 31, and based on the detected center positions of the first reference sphere 911A, the second reference sphere 911B, and the third reference sphere 911C, generates a user coordinate system 901 in the pallet stocker 31 (steps S201 to S210); operates the robot 21 so as to detect the center position of the reference hole 921 as the position of a specific part of the shelf board 510, and based on the detected center position of the reference hole 921, the center position of the reference hole 921 in a state where the pallet 410 is placed on the shelf board 510, and the positional relationship with the position of the first gripping unit 120A, calculates the position of the first gripping unit 120A in the user coordinate system 901 (steps S301 to S310).

[0229] According to such a configuration, the labor required for the teaching operation of the robot 21 can be reduced.

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

Description of Reference Numerals

[0231] 10, 10S, 10T machine tools, 12 machining area, 14 cover body, 16 opening, 18 operation panel, 21 robot, 22 robot base, 23 drive servo motor, 26 base part, 27 first arm, 28 second arm, 29 hand attachment part, 31, 31S, 31T pallet stockers, 51 transfer operation panel, 56, 56h, 56i, 56j, 56k fences, 61, 61S, 61T setup stations, 71 work stocker, 81 hand stocker, 100 transfer system, 101 swivel center axis, 102, 103, 105 pivot center axes, 104, 106 rotation center axes, 113 space, 120 gripping part, 120A first gripping part, 120B second gripping part, 120C third gripping part, 120D fourth gripping part, 121 groove part, 126, 231 center axes, 210 master hand, 220 clamp mechanism, 221 grip insertion hole, 226 piston, 227 protrusion, 230 sensor, 310 work hand, 320 gripping claws, 330 piston cylinder, 340 servo motor, 410 pallet, 510 shelf board, 520, 520p, 520q, 520r pallet support parts, 525 taper cone receiving part, 531 horizontal frame, 532 vertical frame, 533 pin hole, 550 frame body, 551 column, 560 support part, 560A first support part, 560B second support part, 561 plate, 610 control device, 620 robot control part, 621 program memory part, 622 program analysis part, 623 axis control part, 624 hand control part, 625 parameter memory part, 627 pallet stocker position relationship memory part, 630 input / output device, 636 grip position calculation part, 637 user coordinate system generation part, 641, 641Q operation programs, 650 display control part, 660 operation reception part, 670 display part, 671 user coordinate system generation screen, 672, 677 position information display parts, 673, 678 pallet stocker image parts, 675 grip position setting screen, 676 progress display part, 681 first operation part, 682 second operation part, 683 third operation part, 684 fourth operation part, 710 teaching hand, 720 touch probe, 720g contact, 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 parts, 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