Work supply system, work supply method, and work supply program

Abstract

To provide a system, method and program for supplying a work-piece allowing for holding only an uppermost work-piece irrespectively of a stack position of a work-piece group.SOLUTION: A system for supplying a work-piece comprises a work-piece supply robot for carrying an uppermost work-piece from a work-piece group stacked on a work-piece loading table and a robot control unit. The work-piece supply robot includes a robot hand to hold the uppermost work-piece. The robot control unit performs hold-position specifying processing to specify a hold position of the robot hand relative to the work-piece, closest-portion specifying processing to specify a closest portion of the work-piece to the hold position of the robot hand specified by the hold-position specifying processing, rotation-center specifying processing to specify an opposite portion to the closest portion specified by the closest-portion specifying processing as a rotation center, and robot-hand control processing to detach the uppermost work-piece from the work-piece group about the opposite portion specified by the rotation-center specifying processing.SELECTED DRAWING: Figure 12

Description

Technical Field

[0001] The present invention relates to a work supply system, a work supply method, and a work supply program.

Background Art

[0002] Conventionally, a work handling device including a work processing unit has been known (Patent Document 1, etc.). The work processing unit lifts the uppermost work close to a work stacking unit where a plurality of works are stacked and holds it in a substantially vertical state. Further, the work processing unit is configured such that a desired surface of the held work can be gripped by a work handling robot.

[0003] In the work handling device of Patent Document 1, the work processing unit grips the edge portion of the uppermost work stacked in the work stacking unit and rotates it to be in a substantially vertical state. In the work handling device of Patent Document 1, it is possible to lift only the uppermost work so as to turn it over, and it is said that the possibility of lifting two or more works simultaneously can be reduced.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, there is known a processing system configured to photograph the entire placement location with a single camera installed directly above the center of the placement location, identify the position and stacking height of the workpiece based on the photographed image of the workpiece, and control the workpiece holding robot based on the information on the identified position and stacking height of the workpiece (Patent Document 2, etc.). By having such a configuration, the position of the workpiece can be grasped regardless of where the workpiece is stacked on the placement location, and the workpiece holding robot can hold the workpiece.

[0006] However, in the workpiece handling device of Patent Document 1, since the workpiece processing unit always grips and rotates the edge of the workpiece at a fixed position of the workpiece stacking unit, it is necessary to stack the workpiece at a specific position on the workpiece stacking unit, and there is a problem that the advantages of the above-described processing system cannot be utilized.

[0007] One aspect of the present invention is a workpiece supply system, a workpiece supply method, and a workpiece supply program that can hold only the uppermost workpiece regardless of the stacking position of the workpiece group.

Means for Solving the Problems

[0008] A workpiece supply system according to one aspect of the present invention includes a workpiece supply robot configured to be able to convey the uppermost workpiece from a group of workpieces stacked on a workpiece placement table, and a robot control unit. The workpiece supply robot includes a robot hand that holds the uppermost workpiece, and the robot control unit performs a holding position specifying process for specifying a holding position of the robot hand with respect to the workpiece, a nearest neighbor part specifying process for specifying a part of the workpiece closest to the holding position of the robot hand specified by the holding position specifying process, a rotation center specifying process for specifying a rotation center with respect to an opposing part facing the nearest neighbor part specified by the nearest neighbor part specifying process, and a robot hand control process for peeling off the uppermost workpiece from the group of workpieces around the opposing part specified by the rotation center specifying process.

[0009] A work supply method according to one aspect of the present invention includes a holding position specifying process for specifying a holding position of a robot hand with respect to a work, a nearest part specifying process for specifying a part of the work closest to the holding position of the robot hand specified by the holding position specifying process, a rotation center specifying process for specifying a rotation center with respect to an opposing part that opposes the nearest part specified by the nearest part specifying process, and a robot hand control process for separating the uppermost work from the work group with the opposing part specified by the rotation center specifying process as the center.

[0010] A work supply program according to one aspect of the present invention causes a robot control unit to execute a holding position specifying process for specifying a holding position of a robot hand with respect to a work, a nearest part specifying process for specifying a part of the work closest to the holding position of the robot hand specified by the holding position specifying process, a rotation center specifying process for specifying a rotation center with respect to an opposing part that opposes the part specified by the nearest part specifying process, and a robot hand control process for separating the uppermost work from the work group with the opposing part specified by the rotation center specifying process as the center.

[0011] According to a work supply system, a work supply method, and a work supply program according to one aspect of the present invention, by separating the uppermost work from the work group with a rotation center at an opposing part that opposes a part of the work closest to the specified holding position of the robot hand, only the uppermost work can be held regardless of where the work group is loaded on the work placement table.

Effect of the Invention

[0012] According to a work supply system, a work supply method, and a work supply program according to one aspect of the present invention, only the uppermost work can be held regardless of the loading position of the work group.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Embodiments for Carrying Out the Invention

[0014] Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. Note that the following embodiments do not limit the invention according to each claim, and not all combinations of features described in the embodiments are essential for the solution means of the invention.

[0015] [Overall Configuration of Work Supply System According to the First Embodiment] FIG. 1 is a schematic diagram showing a work supply system according to the first embodiment of the present invention. As shown in FIG. 1, the work supply system 1 according to the first embodiment generally includes a work supply robot 100 configured to be able to convey the uppermost work Wt from a group of works W stacked on the work placement table 10. The work supply robot 100 includes a robot hand 120 that holds the uppermost work Wt.

[0016] The work supply system 1 further includes a camera 50 for identifying the group of works W stacked on the work placement table 10, and a control device 200 capable of controlling the work supply robot 100 and the camera 50. Further, the work supply system 1 according to the first embodiment may further include a processing machine such as a bending machine, and may constitute an automatic processing system for the work W together with the processing machine.

[0017] [Configuration of Work Supply Robot] The work supply robot 100 is disposed between the work placement table 10 and the conveyance destination of the work W (for example, a processing machine or the like), holds the work W on the work placement table 10, and is configured to convey the work W toward the conveyance destination such as a processing machine.

[0018] Specifically, as shown in FIG. 1, the work supply robot 100 includes a moving mechanism 160 for moving the work supply robot 100, a robotic hand 120 capable of holding the work W, and an arm portion 140 for approaching or separating the robotic hand 120 from the work W.

[0019] The moving mechanism 160 is a so-called linear motion mechanism having a rail portion 160a laid on the floor surface, a base 160b movable along the rail portion 160a, and a base driving means (not shown) for driving the base 160b. It is configured to move the workpiece supply robot 100 on the floor surface based on a control signal from a robot control unit 230 (to be described later) of the control device 200. Since the moving mechanism 160 can adopt various known configurations, a detailed description thereof is omitted.

[0020] One end of the arm portion 140 is connected to the base 160b of the moving mechanism 160, and the other end is connected to the robot hand 120. Based on a control signal from the robot control unit 230 of the control device 200, it is configured to move the robot hand 120 closer to or away from the workpiece W. In the first embodiment, the arm portion 140 is a multi-joint arm having six control axes, and is capable of not only transporting the workpiece W from the workpiece placement table 10, but also transporting (loading) the workpiece W to a processing machine or the like, assisting in processing (bending) the workpiece W, and transporting (unloading) a product (bent product) from a processing machine or the like. Since the arm portion 140 can adopt various known configurations, a detailed description thereof is omitted. Also, the arm portion 140 is not limited to the configuration of a multi-joint arm having the six control axes described above, and various known configurations can be arbitrarily adopted.

[0021] FIG. 2 is a schematic diagram showing the robot hand of the workpiece supply robot according to the first embodiment. As shown in FIG. 2, the robot hand 120 has a hand body 122 detachably attached to the tip of the arm portion 140, and a plurality of suction portions 124 attached to the hand body 122 and configured to hold the workpiece W. The hand body 122 has a mounting portion 122a detachably attached to the tip of the arm portion 140, a first support bar 122b coupled to the mounting portion 122a, and a plurality of second support bars 122c provided at intervals in the longitudinal direction on the first support bar 122b. Note that the shape of the hand body 122 is not limited to the illustrated example, and can be arbitrarily changed according to the shape of the workpiece W or the like.

[0022] The suction part 124 is attached to both end parts of each second support bar 122c, and is respectively connected to an air suction source (not shown) that sucks air via a pipe. Each suction part 124 has a flat suction pad at its lower end that can be suctioned (contactable) to the surface of the workpiece W. It is configured to suction the surface of the uppermost workpiece Wt from the group of workpieces W loaded on the workpiece mounting table 10 by the suction force of the air by the air suction source. Note that since the robot hand 120 can adopt various known configurations, a detailed description thereof is omitted. Also, the robot hand 120 is not limited to the suction method described above, and various known configurations can be arbitrarily adopted.

[0023] [Configuration of Camera] The camera 50 is provided with one lens and one image sensor each, and as shown in FIG. 1, it is arranged above the workpiece mounting table 10 via a support member such as a camera stand 51 so that at least the whole or a part of the workpiece mounting table 10 can be photographed as a photographing range. In the first embodiment, as shown in FIG. 1, the camera 50 is arranged at a position where it does not interfere with the workpiece supply robot 100, and is configured to photograph the group of workpieces W loaded on the workpiece mounting table 10 from above.

[0024] The camera 50 is configured to supply the captured captured image data to an image processing unit 250 (to be described later) of the control device 200. Note that the camera 50 according to the first embodiment may be configured to directly output a digital signal (captured image data) from the camera 50 to the image processing unit 250, or an analog signal (captured image signal) output from the camera 50 may be converted into a digital signal (captured image data) by an A / D converter (not shown) or the like and output to the image processing unit 250. Further, the camera 50 is configured to be interlockable with an illumination facility L (to be described later) so that the work W group placed on the work placement table 10 is irradiated with illumination light when the work W group is photographed. According to such a configuration, there is an advantage that the edges of the work W group are clarified, and it becomes easier to identify the edges of the work W group when identifying the outer shape and position of the work W group.

[0025] [Configuration of Work Placement Table] As shown in FIG. 1, the work placement table 10 is provided with a magnetic floater 20 at an end on the side of the work supply robot 100. When the magnetic floater 20 is placed on the work placement table 10 with the end face of the work W group abutted against the abutting face 22, the upper work W of the work W group can be lifted by the magnetic force of the magnet.

[0026] In addition, at predetermined locations around the work placement table 10, an end face bar (not shown) and an illumination facility L having a plurality of LEDs (Light-Emitting Diodes) or the like capable of irradiating the placed work W group with irradiation light are provided. The work supply system 1 according to the first embodiment is configured to assist in specifying the work W by the camera 50 by the illumination facility L. Note that since the work placement table 10, the magnetic floater 20, and the illumination facility L can arbitrarily adopt various known configurations, detailed descriptions thereof are omitted.

[0027] [Configuration of Control Device] FIG. 3 is a functional block diagram showing a control device according to the first embodiment. As shown in FIG. 3, the control device 200 includes an input unit 210, a display unit 220, a robot control unit 230, a camera control unit 240, an image processing unit 250, and a storage unit 260. The control device 200 is also connected to the work supply robot 100 and the camera 50 by various known configurations.

[0028] The input unit 210 is constituted by input devices such as a keyboard, a mouse, a push button switch, a tactile switch, and a key lock switch. By operating the input unit 210, in addition to the function of information input usually required in the work supply system 1, for example, operations such as selection of an NC control program described later in the storage unit 260 and selection of a rotation center LC described later can be performed.

[0029] The display unit 220 has a display as a display device. In addition to the function of screen display usually required in the work supply system 1, for example, a selection screen for selecting an NC control program, a captured image of the camera 50, and a confirmation screen of the rotation center LC are displayed. Further, the display unit 220 can be constituted by a touch panel having the function of the input unit 210. When the display unit 220 is constituted by a touch panel, the user can input various information such as selection of an NC control program to the control device 200 by operating the display unit 220, for example.

[0030] Note that the configurations of the input unit 210 and the display unit 220 are not limited to the above-described configurations, and any configuration having an equivalent function instead of these input unit 210 and display unit 220 (for example, display means and input means that can be used remotely, etc.) is not limited thereto.

[0031] The camera control unit 240 is configured to control the shooting operation of the camera 50 based on a shooting program stored in the storage unit 260. The camera control unit 240 also controls the irradiation of the illumination light of the illumination facility L to be linked with the shooting of the camera 50 when the camera 50 shoots the work W group.

[0032] The image processing unit 250 is configured to detect the outer shape of the work W group loaded on the work placement table 10 based on the captured image data supplied from the camera 50, calculate the position (x, y) information of the work W group from the edge detection result, and supply the calculated position information to the robot control unit 230. That is, the image processing unit 250 is configured to be able to function as a work identification device that accurately identifies the position of the uppermost work Wt.

[0033] As shown in FIG. 3, the robot control unit 230 includes a transfer control unit 232, a holding position specifying unit 234, a rectangular approximation unit 236, a nearest part specifying unit 238, and a rotation center specifying unit 239. The holding position specifying unit 234 performs a holding position specifying process for specifying the holding position of the robot hand 120 of the work supply robot 100 with respect to the work W. Specifically, the holding position specifying unit 234 extracts the coordinate data of the work W and the holding position of the robot hand 120 with respect to the work W from the NC control program of the storage unit 260 described later, and specifies the holding position.

[0034] FIG. 4 is a schematic diagram showing the rectangular approximation process of the work according to the first embodiment. As shown in FIG. 4, the rectangular approximation unit 236 is configured to execute a rectangular approximation process for approximating the shape of the work W so as to form a rectangle R that encloses the work W. Specifically, the rectangular approximation unit 236 extracts the contour of the work W from the coordinate data of the work W included in the NC control program of the storage unit 260, calculates the coordinates of the circumscribed rectangle of the point group from the set of coordinates of the point group representing the contour line, and draws the rectangle R. The aspect ratio of the rectangle R varies depending on the shape of the work W for which the rectangular approximation process is executed, and the rectangle R is the smallest rectangle that encloses the work W.

[0035] FIG. 5 is a schematic diagram showing the rectangular approximation process of the work and the robot hand according to the first embodiment. Further, as shown in FIG. 5, when the holding position of the robot hand 120 specified by the holding position specifying unit 234 protrudes from the work W, the rectangular approximation unit 236 approximates the shape of the work W so that the rectangular R including the work W is formed. In addition to the rectangular approximation process, a rectangular approximation process for approximating the rectangular R' including the work W and the robot hand 120 is executed. By having such a configuration, when the work W is peeled off, it is possible to prevent the portion of the robot hand 120 protruding from the work W from sinking into the work placement table 10.

[0036] The nearest part specifying unit 238 performs a nearest part specifying process for specifying the part of the work W closest to the holding position of the robot hand 120 specified by the holding position specifying process of the holding position specifying unit 234. Specifically, the holding position of the robot hand 120 is the end of the suction pad of the suction part 124 of the robot hand 120. Further, the part of the work W is specifically the side of the work W.

[0037] FIG. 6 is a schematic diagram showing the nearest part specifying process of the work according to the first embodiment. As shown in FIG. 6, in the nearest part specifying process, the nearest neighbor side NS is specified based on the rectangle R approximated by the rectangular approximation process of the rectangular approximation unit 236. Specifically, the nearest part specifying unit 238 calculates the distances between the four sides constituting the rectangle R and the ends of the suction pads of the suction part 124 of the robot hand 120 closest to each side, and specifies the side with the shortest distance Lmin as the nearest neighbor side NS. In this specification, the distance between each side of the rectangle R and the end of the suction pad of the suction part 124 is the distance along the direction orthogonal to each side of the rectangle R. When the holding position of the robot hand 120 specified by the holding position specifying unit 234 protrudes from the work W, the end of the suction pad of the suction part 124 protruding from the work W is excluded from the nearest part specifying process of the nearest part specifying unit 238, and the nearest part specifying process is performed based on the end of the suction pad of the suction part 124 within the work W.

[0038] FIG. 7 is a schematic view showing the rotation center of the workpiece according to the first embodiment. As shown in FIG. 7, the rotation center specifying unit 239 performs a rotation center specifying process of specifying, as the rotation center LC, the side facing the nearest part NS specified by the nearest part specifying process of the nearest part specifying unit 238. Further, when the holding position of the robot hand 120 specified by the holding position specifying unit 234 protrudes from the workpiece W, the side of the rectangle R' facing the nearest part NS specified by the nearest part specifying process of the nearest part specifying unit 238 is specified as the rotation center LC.

[0039] FIG. 8 is a schematic view showing the process when there are a plurality of nearest parts of the workpiece according to the first embodiment. FIG. 9 is a schematic view showing the process when there are obstacles around the workpiece according to the first embodiment. As shown in FIG. 8, in the rotation center specifying process of the rotation center specifying unit 239, when two or more nearest sides NS are specified in the nearest part specifying process of the nearest part specifying unit 238, the side facing the longest nearest side NS is specified as the rotation center LC. Further, as shown in FIG. 9, when there are two or more longest nearest sides NS, the side facing the longest nearest side NS with obstacles (for example, the end face bar and the magnetic floater 20, etc.) around is specified as the rotation center LC. The obstacle information around is included in, for example, the NC control program of the storage unit 260 described later, and is obtained as the priority longest nearest side specifying parameter when two or more longest nearest sides NS are specified, but is not limited thereto.

[0040] The transfer control unit 232 is configured to enable CNC control (Computerized Numerical Control) of the workpiece supply robot 100, and performs a robot hand control process of separating the uppermost workpiece Wt from the workpiece W group with the side facing each other specified by the rotation center specifying process of the rotation center specifying unit 239 as the center.

[0041] Specifically, when the transfer control unit 232 transfers (unloads) the workpiece W from the workpiece mounting table 10, based on the NC control program stored in the storage unit 260, the transfer control unit 232 controls the movement mechanism 160 and the arm unit 140 so that the robot hand 120 reaches the uppermost workpiece Wt from the group of workpieces W stacked on the workpiece mounting table 10. Further, when the robot hand 120 reaches the uppermost workpiece Wt, the transfer control unit 232 controls the air suction source so that the robot hand 120 holds the uppermost workpiece Wt, and while rotating the held uppermost workpiece Wt about the rotation center LC, the transfer control unit 232 lifts the workpiece Wt and controls the movement mechanism 160 and the arm unit 140 to transfer the workpiece Wt toward a transfer destination such as a processing machine.

[0042] Furthermore, the robot hand control process of the transfer control unit 232 is configured to hold the uppermost workpiece Wt for a predetermined standby time (for example, 2 seconds, etc.) in a state where the uppermost workpiece Wt is rotated about the opposing part of the uppermost workpiece Wt. The standby time is not limited to the above-described example, and various arbitrary times can be adopted depending on the size of the workpiece W and the like.

[0043] The robot control unit 230 having the above configuration is configured such that the user can select whether to perform a peeling operation of rotating the uppermost workpiece Wt about the rotation center LC. Further, the robot control unit 230 is configured such that the user can change the standby time for holding the uppermost workpiece Wt in a rotated state from the initial setting value. Furthermore, the robot control unit 230 is configured such that the user can change the rotation angle when rotating the uppermost workpiece Wt from the initial setting value. Also, the robot control unit 230 is configured to display a manual adjustment screen for the user to confirm the above-described setting items and perform setting changes on the display unit 220.

[0044] The storage unit 260 stores an NC control program for causing the work supply robot 100 to carry out (unload) the work W from the work placement table 10, carry out (load) the work W to a processing machine or the like, assist in the processing (bending process) of the work W, and carry out (unload) the product (bent product) from the processing machine or the like. Further, the storage unit 260 stores a photographing program, an image processing program, etc. for controlling the camera 50.

[0045] Furthermore, the storage unit 260 stores a work supply program for causing the robot control unit 230 to control the work supply robot 100. The work supply program is configured to cause the robot control unit 230 to execute a holding position specifying process for specifying the holding position of the robot hand 120 with respect to the work W, a nearest part specifying process for specifying the part of the work W closest to the holding position of the robot hand 120 specified by the holding position specifying process, a rotation center specifying process for specifying the opposing part facing the nearest part NS specified by the nearest part specifying process as the rotation center LC, and a robot hand control process for separating the uppermost work Wt from the work W group with the opposing part specified by the rotation center specifying process as the center.

[0046] The control device 200 having the above configuration is configured to display on the display unit 220 a manual adjustment screen on which the user can select whether or not to perform the separation operation of the uppermost work Wt. Further, the control device 200 further displays on the manual adjustment screen the standby time for holding the uppermost work Wt in a state of being rotated about the opposing part of the uppermost work Wt, and the rotation angle when rotating the uppermost work Wt. The control device 200 having such a configuration is configured such that the user can manually change whether or not to perform the separation operation, the standby time, and the rotation angle from the initial setting state by operating the display unit 220 configured by the input unit 210 or the touch panel of the control device 200.

[0047] Note that the rotation center LC specified by the rotation center specifying process of the rotation center specifying unit 239 is configured to be manually changeable. Specifically, on the manual adjustment screen of the display unit 220, rectangles R and R' approximating the uppermost work Wt are displayed together with an image of the uppermost work Wt captured by the camera 50. The rotation center LC specified by the rotation center specifying unit 239 is highlighted in a color different from the other sides of the uppermost work Wt on the rectangles R and R'. Also, the other sides of the uppermost work Wt that can be selected by the user as the rotation center LC are clearly shown on the rectangles R and R' so that the user can identify them. The user can select another side of the uppermost work Wt as the rotation center LC by operating the display unit 220 configured by the input unit 210 or the touch panel of the control device 200.

[0048] Further, the control device 200 may be configured to identify parameters to be changed in order to optimize the effectiveness and effect of the peeling operation based on the shape and size of the work W, the shape and size of the robot hand 120, and the holding position of the robot hand 120, and display them on the display unit 220.

[0049] [Work Supply Method According to the First Embodiment] FIG. 10 is a flowchart showing an example of a work supply method using the work supply system of the first embodiment. Referring to FIG. 10, a series of work supply methods of the work supply system 1 described above will be described. The series of work supply methods are executed during the loading of the work W. Specifically, first, the robot control unit 230 of the control device 200 reads out an NC control program for the work supply robot 100 to convey the work W from the storage unit 260. The holding position specifying unit 234 of the robot control unit 230 of the control device 200 executes a holding position specifying process for specifying the holding position of the robot hand 120 of the work supply robot 100 with respect to the uppermost work Wt of the work W group from the read NC control program (S1: Holding Position Specifying Process Step in FIG. 10).

[0050] After the execution of the holding position specific process, the rectangular approximation unit 236 of the robot control unit 230 of the control device 200 executes a rectangular approximation process. First, the rectangular approximation unit 236 executes different rectangular approximation processes according to the holding position of the uppermost work Wt of the robot hand 120 of the work supply robot 100 specified by the holding position specific process. Specifically, when the robot hand 120 does not protrude from the uppermost work Wt (NO in S2 of FIG. 10), the rectangular approximation unit 236 executes a rectangular approximation process of approximating the shape of the uppermost work Wt to a rectangle R that includes the uppermost work Wt (S3 in FIG. 10). On the other hand, when the robot hand 120 protrudes from the uppermost work Wt (YES in S2 of FIG. 10), a rectangular approximation process of approximating to a rectangle R' that includes the uppermost work Wt and the robot hand 120 is further executed (S5 in FIG. 10).

[0051] After the execution of the rectangular approximation process, the nearest part specifying unit 238 of the robot control unit 230 of the control device 200 executes a nearest part specifying process based on the rectangle R approximated by the rectangular approximation process of the rectangular approximation unit 236. Specifically, the nearest part specifying unit 238 executes a nearest part specifying process of specifying the side of the uppermost work Wt (rectangle R) that is closest to the end of the suction pad of the suction part 124 of the robot hand 120 of the work supply robot 100 specified by the holding position specifying process of the holding position specifying unit 234 as the nearest side NS (S4 in FIG. 10: nearest part specifying process step).

[0052] After the execution of the nearest part specific process, the rotation center identification unit 239 of the robot control unit 230 of the control device 200 executes the following processes according to the number of the nearest sides NS identified by the nearest part identification unit 238 in the nearest part specific process. That is, when the number of the nearest sides NS identified by the nearest part identification unit 238 is one (NO in S6 of FIG. 10), the rotation center identification unit 239 executes a rotation center identification process of identifying the side opposite to the nearest side NS as the rotation center LC (S7 in FIG. 10: rotation center identification process step). When there are a plurality of the nearest sides NS identified by the nearest part identification unit 238 (YES in S6 of FIG. 10), if there is one longest nearest side NS (NO in S11 of FIG. 10), the rotation center identification unit 239 identifies the side opposite to the longest nearest side NS as the rotation center LC (S12 in FIG. 10).

[0053] On the other hand, when there are a plurality of the nearest sides NS identified by the nearest part identification unit 238 of the robot control unit 230 of the control device 200 (YES in S6 of FIG. 10) and there are a plurality of the longest nearest sides NS (YES in S11 of FIG. 10), the rotation center identification unit 239 identifies the side opposite to the longest nearest side NS where there is an obstacle (end face bar or magnetic floater 20) around the uppermost work Wt as the rotation center LC (S13 in FIG. 10).

[0054] After the rotation center LC is identified, the work W group is placed on the mounting table 10, and the work group placed is photographed by the camera 50. Then, the control device 200 corrects the NC control program based on the photographed image data supplied from the camera 50. Simultaneously with or after the correction of the NC control program, the control device 200 displays the rotation center LC identified by the rotation center identification unit 239 of the robot control unit 230 on the display unit 220 (S8 in FIG. 10). Specifically, the rotation center LC identified by the rotation center identification unit 239 is highlighted in a color different from the other sides of the uppermost work Wt on the rectangles R and R' approximating the uppermost work Wt. Also, the other sides of the uppermost work Wt that can be selected by the user as the rotation center LC are clearly shown so that the user can identify them.

[0055] Further, the control device 200 displays on the display unit 220 a manual adjustment screen that allows the user to manually change from the initial setting state whether to perform the peeling operation of the topmost work Wt, the waiting time for holding the topmost work Wt in a rotated state, and the rotation angle when rotating the topmost work Wt.

[0056] The user checks the rotation center LC displayed on the display unit 220 of the control device 200. When the user wants to select a rotation center LC different from the rotation center LC specified by the rotation center specifying unit 239 (NO in S9 of FIG. 10), by operating the input unit 210 of the control device 200 or the display unit 220 configured by the touch panel of the control device 200, the user can select another side of the topmost work Wt as the rotation center LC (S14 of FIG. 10).

[0057] When the user does not manually select the rotation center LC (YES in S9 of FIG. 10), the transfer control unit 232 of the robot control unit 230 of the control device 200 executes a robot hand control process for peeling the topmost work Wt from the work W group with the side specified by the rotation center specifying unit 239 as the rotation center LC (robot hand control process step). On the other hand, when the user manually selects the rotation center LC, the transfer control unit 232 executes a robot hand control process for peeling the topmost work Wt from the work W group with the side selected by the user as the rotation center LC. The work supply robot 100 supplies the topmost work Wt from the work placement table 10 to the processing machine according to the control of the transfer control unit 232 (S10 of FIG. 10).

[0058] FIGS. 11 to 13 are schematic diagrams showing the peeling operation of the topmost work according to the first embodiment. As shown in FIG. 11, in the work supply robot 100, the robot hand 120 moves to the holding position of the uppermost work Wt when the arm portion 140 and the moving mechanism 160 operate. The robot hand 120 holds the uppermost work Wt by adsorbing the adsorption pad of the adsorption portion 124 to the surface of the uppermost work Wt by the suction force from the air suction source. The work supply robot 100 holding the uppermost work Wt peels the uppermost work Wt from the work W group with the side of the uppermost work Wt specified by the rotation center specifying portion 239 of the robot control portion 230 of the control device 200, or the side of the uppermost work Wt manually selected by the user as the rotation center LC, as shown in FIG. 12. The work supply robot 100 holds the uppermost work Wt for a predetermined waiting time in the posture shown in FIG. 12, that is, in a state where the uppermost work Wt is rotated about the opposing portion of the uppermost work Wt. After the elapse of the predetermined waiting time, the work supply robot 100 separates the side of the uppermost work Wt specified or selected as the rotation center LC from the work W group as shown in FIG. 13, and holds the uppermost work Wt so as to be substantially horizontal with respect to the work placement table 10. Thereafter, the work supply robot 100 supplies the uppermost work Wt to the processing machine. Through the above steps, a series of operations of the work supply method by the work supply system 1 according to the first embodiment are executed.

[0059] [Advantages of the work supply system according to the first embodiment] As described above, the work supply system 1 according to the first embodiment includes a work supply robot 100 configured to be able to convey the uppermost work Wt from the group of works W stacked on the work placement table 10, and a robot control unit 230. The work supply robot 100 includes a robot hand 120 that holds the uppermost work Wt. The robot control unit 230 performs a holding position specifying process for specifying the holding position of the robot hand 120 with respect to the work W, a nearest part specifying process for specifying the part (side) of the work W closest to the holding position of the robot hand 120 specified by the holding position specifying process, a rotation center specifying process for specifying the opposing part (side) facing the nearest part (nearest side NS) specified by the nearest part specifying process as the rotation center LC, and a robot hand control process for peeling off the uppermost work Wt from the group of works W with the opposing part specified by the rotation center specifying process as the center.

[0060] And, by having such a configuration, the work supply system 1 according to the first embodiment selects the rotation center LC according to the holding position of the robot hand 120 with respect to the work W, and lifts and peels off the uppermost work Wt obliquely from the group of works W. Therefore, there is an advantage that only the uppermost work Wt can be held regardless of the placement location of the group of works W on the work placement table 10 or the shape of the work W. Furthermore, the inventor has discovered a new finding that the success rate of picking up only the uppermost work Wt from the group of works W increases as the end of the suction pad of the suction part 124 of the robot hand 120 is closer to the end of the work W. Since the work supply system 1 according to the first embodiment uses the opposing part (side) facing the nearest part (nearest side NS) as the rotation center LC, the rotation center LC is far from the holding position of the robot hand 120. That is, since the end of the suction pad is close to the end of the work W (nearest side NS), it has the advantage of being able to more reliably peel off only the uppermost work Wt from the group of works W.

[0061] In addition, in the work supply system 1 according to the first embodiment, the nearest part and the opposing part of the work W are the sides of the work W. By having such a configuration, there is an advantage that the work W can always be lifted at a set rotation angle.

[0062] Furthermore, in the work supply system 1 according to the first embodiment, in the rotation center specifying control process, when two or more nearest parts (nearest sides NS) are specified in the nearest part specifying process, the opposing part (side) that opposes the longest nearest part (nearest side NS) is used as the rotation center LC to separate the uppermost work Wt from the work W group. By having such a configuration, there is an advantage that it is possible to more reliably separate only the uppermost work Wt from the work W group compared to the case where the opposing part (side) that opposes the other specified nearest part (nearest side NS) is used as the rotation center LC.

[0063] In addition, in the work supply system 1 according to the first embodiment, in the rotation center specifying process, when there are two or more longest nearest parts (nearest sides NS), the opposing part (side) that opposes the longest nearest part (nearest side NS) with an obstacle in the vicinity is used as the rotation center LC to separate the uppermost work Wt from the work W group. By having such a configuration, there is an advantage that it is possible to prevent the robot hand 120 of the work supply robot 100 from interfering with the obstacle when separating the uppermost work Wt from the work W group.

[0064] Furthermore, in the work supply system 1 according to the first embodiment, the robot control unit 230 is configured to further execute a rectangular approximation process for approximating the shape of the work W so as to form a rectangle R that includes the work W, and the nearest part specifying process specifies the nearest part based on the rectangle R approximated by the rectangular approximation process. By having such a configuration, there is an advantage that even when the work W has a complex shape, it is possible to specify an appropriate nearest part (nearest side NS) and thus the rotation center LC by simplifying the shape by rectangular approximation.

[0065] Also, in the work supply system 1 according to the first embodiment, the robot hand control process is configured to hold the topmost work Wt for a predetermined waiting time in a state where the topmost work Wt is rotated about the opposing part of the topmost work Wt. By having such a configuration, even if the work W directly below adheres to the topmost work Wt, the work W directly below peels off from the topmost work Wt due to its own weight, and thus there is an advantage that only the topmost work Wt can be peeled off from the work W group.

[0066] [Overall Configuration of Work Supply System According to Second Embodiment] Next, the work supply system 1' according to the second embodiment will be described. In the second embodiment, the same reference numerals are given to the parts that perform the same functions as those in the first embodiment, and redundant explanations are omitted.

[0067] In the work supply system 1' according to the second embodiment, the nearest part specifying unit 238 performs a nearest part specifying process of specifying the part of the work W closest to the holding position of the robot hand 120 specified by the holding position specifying process of the holding position specifying unit 234. Specifically, the holding position of the robot hand 120 is the end of the suction pad of the suction part 124 of the robot hand 120. Also, specifically, the part of the work W is the corner of the work W.

[0068] FIG. 14 is a schematic diagram showing the nearest part specifying process of the work according to the second embodiment. As shown in FIG. 14, the nearest part specifying process specifies the nearest neighbor corner (nearest neibour corner) NC based on the rectangle R approximated by the rectangle approximation process of the rectangle approximation unit 236. Specifically, the nearest part specifying unit 238 calculates the distances between the four corners constituting the rectangle R and the ends of the suction pads of the suction part 124 of the robot hand 120 closest to each corner, and specifies the corner with the shortest distance Lmin as the nearest neighbor corner NC.

[0069] FIG. 15 is a schematic diagram showing the rotation center of the work according to the second embodiment. As shown in FIG. 15, the transfer control unit 232 performs a robot hand control process for separating the uppermost workpiece Wt from the group of workpieces W with the angle opposite to the nearest angle NC specified by the nearest part specifying process of the nearest part specifying unit 238 as the rotation center LC.

[0070] The robot hand control process of the transfer control unit 232 is configured to hold the uppermost workpiece Wt for a predetermined waiting time (for example, 2 seconds, etc.) in a state where the nearest angle NC of the uppermost workpiece Wt is separated from the group of workpieces W and the angle opposite to the nearest angle NC is not separated from the group of workpieces W. The waiting time is not limited to the above-described example, and various arbitrary times can be adopted depending on the size of the workpiece W and the like.

[0071] [Advantages of the workpiece supply system according to the second embodiment] As described above, the workpiece supply system 1' according to the second embodiment, like the first embodiment, selects the rotation center LC according to the holding position of the robot hand 120 and separates the uppermost workpiece Wt from the group of workpieces W. Therefore, it has the advantage that only the uppermost workpiece Wt can be held regardless of the stacking position of the group of workpieces W.

[0072] Furthermore, in the workpiece supply system 1 according to the second embodiment, the nearest part and the opposing part of the workpiece W are the corners of the workpiece W. By having such a configuration, even when the approximate line and the actual workpiece are far apart, there is an advantage that the corners can be aligned.

[0073] Also, the workpiece supply system 1' according to the second embodiment, like the first embodiment, is configured such that the robot control unit 230 further performs a rectangular approximation process for approximating the shape of the workpiece W to a rectangle R including the workpiece W, and the nearest part specifying process is configured to specify the nearest part (nearest angle NC) based on the rectangle R approximated by the rectangular approximation process. Thereby, the workpiece supply system 1' has the advantage that, like the first embodiment, even when the workpiece W has a complex shape, an appropriate rotation center LC can be specified by simplifying the shape.

[0074] Further, similar to the first embodiment, in the work supply system 1' according to the second embodiment, the robot hand control process is configured to hold the uppermost work Wt for a predetermined waiting time in a state where the nearest part (nearest corner NC) of the uppermost work Wt is detached from the work W and the opposing part (corner) facing the nearest part (nearest corner NC) is not detached from the group of works W. Thereby, similar to the first embodiment, even when the work W below the uppermost work Wt is attached to the uppermost work Wt, the work supply system 1' has the advantage that only the uppermost work Wt can be detached from the group of works W because the work W detaches from the uppermost work Wt by its own weight.

[0075] [Modification Example] As described above, the preferred embodiments of the present invention have been described. However, the technical scope of the present invention is not limited to the scope described in the first and second embodiments. Various changes or improvements can be made to the above-described embodiments.

[0076] For example, in the above-described first embodiment, the nearest part and the opposing part of the work W are described as the sides of the work W, and in the above-described second embodiment, the nearest part and the opposing part of the work W are described as the corners of the work W. However, the present invention is not limited to this. For example, the nearest part and the opposing part of the work W may be any part other than the sides or corners of the work W.

[0077] In the above-described first embodiment, the rotation center specifying process is described as detaching the uppermost work Wt from the group of works W with the opposing part (side) facing the longest nearest part (nearest side NS) as the rotation center LC when two or more nearest parts (nearest sides NS) are specified in the nearest part specifying process. However, the present invention is not limited to this. The robot hand control process may detach the uppermost work Wt from the group of works W with the opposing part (side) facing another nearest part (nearest side NS) as the rotation center LC.

[0078] In the above-described first embodiment, the rotation center identification process has been described as separating the uppermost workpiece Wt from the workpiece W group with the opposing part (side) facing the longest nearest part (nearest side NS) with obstacles around it as the rotation center LC when there are two or more longest nearest parts (nearest sides NS). However, the present invention is not limited to this. The robot hand control process may separate the uppermost workpiece Wt from the workpiece W group with the opposing part (side) facing another nearest part (nearest side NS) as the rotation center LC.

[0079] In the above-described first and second embodiments, the robot control unit 230 is configured to further perform a rectangular approximation process for approximating the shape of the workpiece W so as to form a rectangle R including the workpiece W, and the nearest part identification process has been described as identifying the nearest part based on the rectangle R approximated by the rectangular approximation process. However, the present invention is not limited to this. The robot control unit 230 may perform the nearest part identification process based on the shape of the workpiece W without performing the rectangular approximation process.

[0080] In the above-described first and second embodiments, the robot hand control process has been described as being configured to hold the uppermost workpiece Wt for a predetermined standby time in a state where the uppermost workpiece Wt is rotated about the opposing part of the uppermost workpiece Wt. However, the present invention is not limited to this. The robot hand control process may immediately separate the opposing part (side, corner) of the uppermost workpiece Wt from the workpiece W group from the above-described state.

[0081] In the above-described first and second embodiments, the holding position of the robot hand 120 has been described as the end of the suction pad of the suction part 124 of the robot hand 120. However, the present invention is not limited to this, and it may be the center of the suction pad of the suction part 124 or the end of the hand body 122 of the robot hand 120.

[0082] In the workpiece supply methods of the above-described first and second embodiments, after the rotation center LC is specified, the workpiece W group has been described as being placed on the mounting table 10. However, the present invention is not limited to this, and the workpiece W group may be placed on the mounting table 10 before or during the specification of the rotation center LC.

Explanation of Signs

[0083] 1,1′ Workpiece supply system 10 Workpiece mounting table 20 Magneto - floater 22 Abutting surface 50 Camera 51 Camera stand 100 Workpiece supply robot 120 Robot hand 122 Hand body 122a Mounting part 122b First support bar 122c Second support bar 124 Suction part 140 Arm part 160 Moving mechanism 160a Rail part 160b Base table 200 Control device 210 Input part 220 Display part 230 Robot control part 232 Conveyance control part 234 Holding position specifying part 236 Rectangle approximation part 238 Nearest - neighbor part specifying part 239 Rotation center specifying part 240 Camera control part 250 Image processing part 260 Storage part L Lighting equipment LC Rotation center Lmin Shortest distance NC Nearest - neighbor angle (nearest - neighbor part) NS Nearest - neighbor side (nearest - neighbor part) R,R′ Rectangle W Workpiece Topmost Work Wt

Claims

1. A work supply robot configured to be able to convey the uppermost work from a group of works loaded on a work placement table, a robot control unit, and comprising: the work supply robot includes a robot hand that holds the uppermost work, the robot control unit: a holding position specifying process for specifying the holding position of the robot hand with respect to the work; a rectangular approximation process for approximating the shape of the work so as to form a rectangle including the work; a nearest neighbor part specifying process for specifying, as a nearest neighbor part, the side or corner of the rectangle approximated by the rectangular approximation process that is closest to the holding position of the robot hand specified by the holding position specifying process; a rotation center specifying process for specifying, as a rotation center, an opposing part that opposes the nearest neighbor part specified by the nearest neighbor part specifying process; a robot hand control process for rotating and lifting the uppermost work upward about the opposing part specified by the rotation center specifying process and peeling it off from the group of works; and performing: the opposing part is a side or corner of the rectangle that opposes the nearest neighbor part A work supply system.

2. In the rotation center specifying process, when two or more sides of the rectangle are specified as the nearest neighbor part in the nearest neighbor part specifying process, the opposing part that opposes the longest nearest neighbor part, which is the longest side among the two or more sides, is specified as the rotation center. The work supply system according to Claim 1.

3. In the rotation center specifying process, when there are two or more longest nearest neighbor parts, the opposing part that opposes the longest nearest neighbor part having an obstacle in the vicinity is specified as the rotation center. The work supply system according to Claim 2.

4. The robot hand control process is configured to hold the uppermost work for a predetermined waiting time while rotating and lifting the uppermost work about the opposing part of the uppermost work. The work supply system according to any one of Claims 1 to 3.

5. A holding position specifying process step for specifying the holding position of the robot hand with respect to the work; a rectangular approximation step for approximating the shape of the work so as to form a rectangle including the work; a nearest neighbor part specifying process step for specifying, as a nearest neighbor part, the side or corner of the rectangle approximated by the rectangular approximation step that is closest to the holding position of the robot hand specified by the holding position specifying process; A rotation center specifying process step of specifying, with respect to an opposing part facing the nearest part specified by the nearest part specifying process, the opposing part as a rotation center; A robot hand control process step of lifting and separating the uppermost workpiece from the workpiece group while rotating the uppermost workpiece upward with the opposing part specified by the rotation center specifying process as the center; Comprising: The opposing part is a side or a corner of the rectangle facing the nearest part; A workpiece supply method.

6. A holding position specifying process of specifying a holding position of a robot hand with respect to a workpiece; A rectangle approximation process of approximating the shape of the workpiece so as to form a rectangle including the workpiece; A nearest part specifying process of specifying, as a nearest part, the side or the corner of the rectangle approximated by the rectangle approximation process that is closest to the holding position of the robot hand specified by the holding position specifying process among the sides or corners of the rectangle; A rotation center specifying process of specifying, with respect to an opposing part facing the nearest part specified by the nearest part specifying process, the opposing part as a rotation center; A robot hand control process of lifting and separating the uppermost workpiece from the workpiece group while rotating the uppermost workpiece upward with the opposing part specified by the rotation center specifying process as the center; Causing a robot control unit to execute; The opposing part is a side or a corner of the rectangle facing the nearest part; A workpiece supply program.

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