Method for determining the positions of three or more holders, workpiece transfer device, laser processing system, and program

Abstract

The present invention provides a method for determining the positions of three or more holders, a workpiece handling device, a laser processing system, and a program that can determine the positions of multiple holders without depending on the operator's experience. [Solution] A method for determining the positions of three or more holders comprises the steps of: determining a first position of a first holder that holds a first workpiece based on the shape of a first workpiece; determining a second position of a second holder that holds a first workpiece based on the shape of the first workpiece and a first length from the first holder; and determining a third position of a third holder that holds a first workpiece based on the shape of the first workpiece, a first length from the first holder, and a second length from the second holder.

Description

【Technical Field】 【0001】 The present invention relates to a method for determining the positions of three or more holders, a workpiece transfer device, a laser processing system, and a program. 【Background Art】 【0002】 A technique for changing the position of a suction means in a transfer device for transferring a workpiece is known. 【0003】 As a related technique, Patent Document 1 discloses a component sorting device. The component sorting device described in Patent Document 1 includes an image display unit that displays an image of a component and a suction means, and a suction position指示 means that can be operated by an operator and can指示 the suction position of the suction means with respect to the component displayed as an image on the image display unit. 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2000-190171 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 An object of the present invention is to provide a method for determining the positions of three or more holders, a workpiece transfer device, a laser processing system, and a program that can determine the positions of a plurality of holders without depending on the experience of an operator. 【Means for Solving the Problems】 【0006】 Embodiments of the present invention relate to a method for determining the positions of three or more holders, a workpiece transfer device, a laser processing system, and a program shown below. 【0007】 (1) A step of determining the first position of the first holder that holds the first workpiece based on the shape of the first workpiece, A step of determining the second position of the second holder that holds the first workpiece based on the shape of the first workpiece and the first length from the first holder, A step of determining the third position of the third holder that holds the first workpiece based on the shape of the first workpiece, the first length from the first holder, and the second length from the second holder. It is equipped with, The steps for determining the second position and the third position are performed by a computer. A method for determining the positions of three or more holders. (2) The step of determining the third position is: This includes determining the third position such that the smaller of the length from the first position to the third position and the length from the second position to the third position is substantially maximized. A method for determining the positions of the three or more retainers described in (1) above. (3) The step of generating a first map showing the distribution of the first length from the first holder, The step of determining the second position includes determining the second position based on the first map. A method for determining the positions of three or more retainers as described in (1) or (2) above. (4) The process includes generating a second map which is a combination of the distribution of the first length from the first holder and the distribution of the second length from the second holder. The step of determining the third position includes determining the third position based on the second map. A method for determining the positions of three or more retainers as described in any one of (1) to (3) above. (5) The step of determining the first position includes determining the first position based on the center of gravity of the first workpiece. A method for determining the positions of three or more holders as described in any one of (1) to (4) above. (6) If the first workpiece has an opening, the first length from the first holder is the length that bypasses the opening. A method for determining the positions of three or more retainers as described in any one of (1) to (5) above. (7) The step of determining the second position includes determining the second position based on the shape of the first workpiece, the first length, and the conditions around each point on the shape of the first workpiece. A method for determining the positions of three or more holders as described in any one of (1) to (6) above. (8) The process comprises dividing the shape of the first workpiece into a plurality of surface elements, The first map is generated based on the length from the first holder to each of the plurality of face elements. A method for determining the positions of the three or more retainers described in (3) above. (9) The process of displaying the plurality of surface elements on a display in different colors according to the length from the first holder to each of the plurality of surface elements. A method for determining the positions of the three or more retainers described in (8) above. (10) If the second holder positioned at the determined second position overlaps with the hole of the first workpiece, the second position is corrected such that the length from the first holder to the second holder is shortened until the overlap between the second holder and the hole is eliminated. A method for determining the positions of three or more retainers as described in any one of (1) to (9) above. (11) A step of acquiring shape data of the shape that includes the first workpiece, A step of extracting the shape of the first workpiece and the shape of the second workpiece separated from the first workpiece from the acquired shape data. Equipped with A method for determining the positions of three or more retainers as described in any one of (1) to (10) above. (12) The method comprises the step of determining the position of at least one other holder such that the first holder located at the first position, the second holder located at the second position, and the third holder located at the third position simultaneously hold the first workpiece and the second workpiece, separated from the first workpiece, is held by at least one other holder. A method for determining the positions of three or more retainers as described in any one of (1) to (10) above. (13) A step of determining the first position of the first holder that holds the first workpiece based on the shape of the first workpiece, A step of determining the second position of the second holder that holds the first workpiece based on the shape of the first workpiece and the first length from the first holder, A step of determining the third position of the third holder that holds the first workpiece based on the shape of the first workpiece, the first length from the first holder, and the second length from the second holder. Equipped with A program that instructs a computer to execute a method. (14) A plurality of holders including a first holder, a second holder, and a third holder, A moving device for moving a support that supports the plurality of holders, A memory for storing the shape of the first workpiece, A calculation device that determines the first position of the first holder that holds the first workpiece based on the shape of the first workpiece, determines the second position of the second holder that holds the first workpiece based on the shape of the first workpiece and a first length from the first holder, and determines the third position of the third holder that holds the first workpiece based on the shape of the first workpiece, a first length from the first holder, and a second length from the second holder. Equipped with Workpiece transport device. (15) A laser processing apparatus that forms a plurality of workpieces, including a first workpiece, from a raw material workpiece by irradiating the workpiece with a laser, A work transfer device that transfers the plurality of workpieces using a plurality of holders including a first holder, a second holder, and a third holder, a memory that stores the shape of the first workpiece, an arithmetic unit that determines a first position of the first holder that holds the first workpiece based on the shape of the first workpiece, determines a second position of the second holder that holds the first workpiece based on the shape of the first workpiece and a first length from the first holder, and determines a third position of the third holder that holds the first workpiece based on the shape of the first workpiece, the first length from the first holder, and a second length from the second holder comprising a laser processing system. 【Advantages of the Invention】 【0008】 According to the present invention, it is possible to provide a method for determining the positions of three or more holders, a work transfer device, a laser processing system, and a program that can determine the positions of a plurality of holders without depending on the experience of an operator. 【Brief Description of the Drawings】 【0009】 [Figure 1] FIG. 1 is a schematic perspective view schematically showing a part of a work transfer device. [Figure 2] FIG. 2 is a diagram schematically showing a computer. [Figure 3] FIG. 3 is a diagram schematically showing an example in which the first position of the first holder is determined based on an input from an operator. [Figure 4] FIG. 4 is a diagram schematically showing a state in which the second positioning step is executed. [Figure 5] FIG. 5 is a diagram schematically showing a state in which the third positioning step is executed. [Figure 6] FIG. 6 is a diagram schematically showing a state after determining the first position of the first holder, the second position of the second holder, and the third position of the third holder without depending on the center of gravity position of the first workpiece. [Figure 7] Figure 7 is a schematic diagram showing how the fourth position determination process is performed. [Figure 8] Figure 8 is a schematic diagram showing how the fifth position determination process is performed. [Figure 9] Figure 9 is a schematic diagram showing how the first position determination process is performed. [Figure 10] Figure 10 is a schematic diagram illustrating the first example of determining the second position. [Figure 11] Figure 11 is a schematic diagram illustrating the first example of determining the third position. [Figure 12] Figure 12 schematically illustrates a second example of determining the third position. [Figure 13] Figure 13 schematically illustrates a second example of determining the second position. [Figure 14] Figure 14 schematically illustrates a third example of determining the third position. [Figure 15] Figure 15 schematically illustrates a fourth example of determining the third position. [Figure 16] Figure 16 is a schematic diagram showing how the first map was generated. [Figure 17] Figure 17 is a schematic diagram illustrating how the second map is generated. [Figure 18] Figure 18 schematically shows how the composite map is generated. [Figure 19] Figure 19 schematically shows how the third map is generated. [Figure 20] Figure 20 schematically shows how the fourth map was generated. [Figure 21] Figure 21 is a schematic diagram showing the state after the positions of multiple holders have been determined. [Figure 22] Figure 22 schematically shows how the first map, which represents the distribution of linear lengths from the first holder, is generated. [Figure 23] Figure 23 schematically shows how the second map is generated in the fourth example of determining the third position. [Figure 24]Figure 24 is a schematic plan view illustrating an example of the first workpiece. [Figure 25] Figure 25 schematically shows how the first map is generated, which shows the distribution of the first length from the first retainer that bypasses the slits and holes. [Figure 26] Figure 26 schematically shows how a second map is generated, which combines the distribution of a first length from the first retainer bypassing the slit and hole, and the distribution of a second length from the second retainer bypassing the slit and hole. [Figure 27] Figure 27 schematically shows an example in which the value of the first length from the first holder is added and corrected by a predetermined value when crossing a slit line. [Figure 28] Figure 28 schematically shows how the second position is corrected so that the overlap between the second retainer and the hole is eliminated. [Figure 29] Figure 29 is a diagram illustrating the permissible region in which the placement of the retainer is permitted. [Figure 30] Figure 30 shows an example in which the positions of multiple retainers are determined based on the tolerance region. [Figure 31] Figure 31 schematically shows how the process of acquiring shape data of the shape containing the first workpiece is performed. [Figure 32] Figure 32 schematically shows the state in which the first shape of the first workpiece has been extracted from the shape data. [Figure 33] Figure 33 schematically shows the state after the positions of the first group of holders that hold the first workpiece and the second group of holders that hold the second workpiece have been determined. [Figure 34] Figure 34 is a flowchart showing an example of a method for determining the positions of three or more retainers in the first embodiment. [Figure 35] Figure 35 is a schematic diagram showing the workpiece transfer device in the second embodiment. [Figure 36] Figure 36 is a schematic diagram of a computer. [Figure 37]Figure 37 is a schematic perspective view showing a state in which multiple holders are supported by a support. [Figure 38] Figure 38 is a schematic perspective view showing how multiple attachments can be detached from the support. [Figure 39] Figure 39 is a schematic perspective view illustrating how a third workpiece is transported using multiple holders arranged in the first layout. [Figure 40] Figure 40 is a schematic perspective view illustrating how the first workpiece is transported using multiple holders arranged in the second layout. [Figure 41] Figure 41 is a schematic cross-sectional view illustrating the state in which the first attachment and the second attachment are mounted on the support. [Figure 42] Figure 42 is a schematic perspective view illustrating the workpiece transfer device in the second embodiment. [Figure 43] Figure 43 is a schematic perspective view showing a portion of the workpiece transfer device in the second embodiment. [Figure 44] Figure 44 is a schematic diagram illustrating how a control device can control multiple devices. [Figure 45] Figure 45 schematically shows how the first position change mode is executed. [Figure 46] Figure 46 is a schematic diagram illustrating the execution of the third transport mode. [Figure 47] Figure 47 is a schematic diagram illustrating how the first transport mode is executed. [Figure 48] Figure 48 schematically illustrates how the second transport mode is executed. [Figure 49] Figure 49 is a schematic perspective view illustrating how the first and second workpieces are transported simultaneously. [Figure 50] Figure 50 is a schematic diagram showing the laser processing system in the third embodiment. [Figure 51] Figure 51 is a schematic perspective view illustrating a portion of the laser processing system in the third embodiment. [Figure 52] Figure 52 schematically shows how the process of acquiring shape data of the shape containing the first workpiece is performed. [Figure 53] Figure 53 is a diagram illustrating the creation of nesting data files. [Figure 54] Figure 54 is a flowchart showing an example of a workpiece transport method in the fourth embodiment. [Figure 55] Figure 55 is a schematic diagram showing an example of a non-volatile storage medium on which a program is recorded. [Figure 56] Figure 56 is a schematic diagram showing a second workpiece transport device included in the laser processing system. [Modes for carrying out the invention] 【0010】 The following description of the embodiment will explain the method for determining the positions of three or more holders, the workpiece transport device 10, the laser processing system 100, and the program, with reference to the drawings. In the following description of the embodiment, parts and components having the same function will be denoted by the same reference numerals, and repeated explanations of parts and components denoted by the same reference numerals will be omitted. 【0011】 (First Embodiment) A method for determining the positions of three or more holders in the first embodiment will be described with reference to Figures 1 to 34. Figure 1 is a schematic perspective view showing a part of the workpiece transfer device 10. Figure 2 is a schematic diagram showing the computer 60. Figure 3 is a schematic diagram showing an example in which the first position P1 of the first holder 31a is determined based on input from the operator. Figure 4 is a schematic diagram showing the execution of the second position determination process. Figure 5 is a schematic diagram showing the execution of the third position determination process. Figure 6 is a schematic diagram showing the state after the first position P1 of the first holder 31a, the second position P2 of the second holder 31b, and the third position P3 of the third holder 31c have been determined without regard to the center of gravity position of the first workpiece 91. Figure 7 is a schematic diagram showing the execution of the fourth position determination process. Figure 8 is a schematic diagram showing the execution of the fifth position determination process. Figure 9 schematically shows how the first position determination process is performed. Figure 10 schematically shows the first example of determining the second position P2. Figure 11 schematically shows the first example of determining the third position P3. Figure 12 schematically shows the second example of determining the third position P3. Figure 13 schematically shows the second example of determining the second position P2. Figure 14 schematically shows the third example of determining the third position P3. Figure 15 schematically shows the fourth example of determining the third position P3. Figure 16 schematically shows how the first map MP1 is generated. Figure 17 schematically shows how the second map MP2 is generated. Figure 18 schematically shows how the composite map MB is generated. Figure 19 schematically shows how the third map MP3 is generated. Figure 20 schematically shows how the fourth map MP4 is generated. Figure 21 schematically shows the state after the positions of the multiple holders 31 have been determined. Figure 22 schematically shows how the first map MP1, which shows the distribution of linear lengths from the first holder 31a, is generated. Figure 23 schematically shows how the second map MP2 is generated in the fourth example of determining the third position P3. Figure 24 is a schematic plan view schematically showing an example of the first workpiece 91.Figure 25 schematically shows how a first map MP1 is generated, which shows the distribution of the first length from the first retainer 31a that bypasses the slit SL and the hole HP. Figure 26 schematically shows how a second map MP2 is generated, which is a combination of the distribution of the first length from the first retainer 31a that bypasses the slit SL and the hole HP and the distribution of the second length from the second retainer 31b that bypasses the slit SL and the hole HP. Figure 27 schematically shows an example in which the value of the first length L1 from the first retainer 31a is added and corrected by a predetermined value when crossing the slit line SS. Figure 28 schematically shows how the second position P2 is corrected so that the overlap between the second retainer 31b and the hole HP is eliminated. Figure 29 is a diagram for explaining the allowable region BR in which the arrangement of retainers is permitted. Figure 30 is a diagram showing an example in which the positions of multiple retainers are determined based on the allowable region BR. Figure 31 is a schematic diagram showing the process of acquiring shape data SH of shape S, which includes the first workpiece 91. Figure 32 is a schematic diagram showing the state after the first shape S1 of the first workpiece 91 has been extracted from the shape data SH. Figure 33 is a schematic diagram showing the state after the positions of the first group of holders 31-1 that hold the first workpiece 91 and the second group of holders 31-2 that hold the second workpiece 92 have been determined. Figure 34 is a flowchart showing an example of a method for determining the positions of three or more holders in the first embodiment. 【0012】 As illustrated in Figure 1, the workpiece transfer device 10 comprises at least three holders 31, including a first holder 31a, a second holder 31b, and a third holder 31c. 【0013】 The first holder 31a may be a holder that holds the workpiece by magnetic force, or a holder that holds the workpiece by vacuum attraction force. The first holder 31a may be a first electromagnet, or a first vacuum suction pad. 【0014】 The second holder 31b may be a holder that holds the workpiece by magnetic force, or a holder that holds the workpiece by vacuum attraction. The second holder 31b may be a second electromagnet, or a second vacuum suction pad. 【0015】 The third holder 31c may be a holder that holds the workpiece by magnetic force, or a holder that holds the workpiece by vacuum attraction. The third holder 31c may be a third electromagnet, or a third vacuum suction pad. 【0016】 The workpiece transfer device 10 may include a fourth holder 31d and / or a fifth holder 31e. The workpiece transfer device 10 may also include a sixth holder 31f. 【0017】 As illustrated in Figure 2, in the first step ST1, the position of the first holder 31a that holds the first workpiece 91 (hereinafter referred to as "first position P1") is determined based on the shape of the first workpiece 91 (hereinafter referred to as "first shape S1") (more specifically, based on the position G1 of the center of gravity of the first workpiece 91 derived from the shape of the first workpiece 91). The first step ST1 is the first position determination step. 【0018】 The step of determining the first position P1 of the first holder 31a (in other words, the first position determination step) may be performed automatically by the computer 60 (see Figure 2). Alternatively, as illustrated in Figure 3, the first position P1 of the first holder 31a may be determined based on input from an operator. Alternatively, the first position P1 automatically determined by the computer 60 may be adjusted or corrected by the operator. For example, the first position P1 determined by the computer 60 may be adjusted or corrected by the operator via the input device 66 of the computer 60. 【0019】 In this specification, the surface of the first workpiece 91 held by the plurality of holders 31 is defined as the first main surface 91m. In the example shown in Figures 2 and 3, the first position P1 is on the first main surface 91m. 【0020】 In the examples shown in Figures 2 and 3, the centroid position G1 of the first workpiece 91 is located inside the outer edge of the first workpiece 91. In this case, the first position P1 of the first holder 31a that holds the first workpiece 91 may be determined to be a position that coincides with the centroid position G1. More specifically, the first position P1 may be determined to be the intersection of the first normal, which passes through the centroid position G1 and is perpendicular to the first main surface 91m, and the first main surface 91m. However, if there are problems such as the first holder 31a not being able to properly hold the first workpiece 91 even if the first holder 31a is placed at the intersection, the first position P1 may be determined to be in the vicinity of the intersection. 【0021】 As illustrated in Figure 4, in the second step ST2, the position of the second holder 31b that holds the first workpiece 91 (hereinafter referred to as "second position P2") is determined based on the first shape S1 of the first workpiece 91 and the first length L1 from the first holder 31a. The second step ST2 is a second position determination step. In the example shown in Figure 2, the second position P2 is located on the first main surface 91m where the first workpiece 91 is prone to bending. 【0022】 The process of determining the second position P2 of the second holder 31b (in other words, the second position determination process) is performed by the computer 60. The second position P2 determined by the computer 60 may be adjusted or corrected by the operator via the input device 66 of the computer 60. In the example shown in Figure 4, the second position determination process (second step ST2) is performed after the first position determination process (first step ST1) is performed. 【0023】 This allows the second position P2 to be determined sequentially from the first position P1, and the positions of the first retainer 31a and the second retainer 31b to be determined without relying on the operator's experience. 【0024】 In the example shown in Figure 4, the second position determination step (second step ST2) includes determining the second position P2 of the second holder 31b that holds the first workpiece 91 such that the length LT1 from the first holder 31a to the second holder 31b is substantially maximized. As illustrated in Figure 4, the computer 60 may narrow down the candidates for the second position P2 by repeatedly eliminating points from which the length from the first holder 31a is less than the first length L1, and then incrementing the first length L1. 【0025】 In the example shown in Figure 4, the position A1 on the first main surface 91m furthest from the first position P1 of the first holder 31a is on the edge 91e of the first workpiece 91. If the second holder 31b is placed on the edge 91e, a portion of the second holder 31b will protrude from the first workpiece 91. Therefore, in order to prevent a portion of the second holder 31b from protruding from the first workpiece 91, the second position P2 of the second holder 31b is not the position that strictly maximizes the length LT1 from the first holder 31a to the second holder 31b, but is permitted to be in the vicinity of the position that strictly maximizes said length LT1. 【0026】 In the example shown in Figure 4, the second position determination step (in other words, the step of determining the second position P2 of the second holder 31b) includes the computer 60 determining the second position P2 such that the condition is met that the entire workpiece holding surface of the second holder 31b is in contact with the first workpiece 91. More specifically, the second position determination step may include the computer 60 determining the second position P2 based on the first shape S1 of the first workpiece 91, the first length L1 described above, and the size of the second holder 31b, such that the condition is met that the entire workpiece holding surface of the second holder 31b is in contact with the first workpiece 91. If the shape of the second holder 31b is circular, the size of the second holder 31b described above may be the outer diameter of the second holder 31b. 【0027】 As illustrated in Figure 5, in the third step ST3, the position of the third holder 31c that holds the first workpiece 91 (hereinafter referred to as "third position P3") is determined based on the first shape S1 of the first workpiece 91, the first length L1 from the first holder 31a, and the second length L2 from the second holder 31b. The third step ST3 is a third position determination step. In Figure 5, the third position P3 is on the first main surface 91m. 【0028】 In the example shown in Figure 5, the third position determination step (third step ST3) is executed after the second position determination step (second step ST2). In the examples shown in Figures 4 and 5, the first position determination step (first step ST1), the second position determination step (second step ST2), and the third position determination step (third step ST3) are executed sequentially in this order. 【0029】 The process of determining the third position P3 of the third holder 31c (in other words, the third position determination process) is performed by the computer 60. The third position P3 determined by the computer 60 may be adjusted or corrected by the operator via the input device 66 of the computer 60. 【0030】 In the method for determining the positions of three or more holders in the first embodiment, the positions of multiple holders 31, including the second holder 31b and the third holder 31c, can be determined without relying on the operator's experience. Therefore, the workload of the operator is reduced. In addition, it is prevented that the arrangement of the multiple holders 31 will be in an inappropriate position. 【0031】 In the example shown in Figure 2, the first position P1 of the first holder 31a is determined based on the center of gravity position G1 of the first workpiece 91. In this case, the first holder 31a is positioned at or near the center of gravity position G1, regardless of the operator's experience, thus preventing the area around the center of gravity of the first workpiece 91 from bending downward during transport. Therefore, the posture of the first workpiece 91 is stabilized during transport. 【0032】 However, as illustrated in Figure 6, even if the first position P1 of the first holder 31a is not determined based on the center of gravity position G1, the method for determining the positions of three or more holders in the first embodiment still functions without problems, although it is not optimal. Therefore, in the first embodiment, the determination of the first position P1 may be performed independently of the center of gravity position G1 of the first workpiece 91. In the example shown in Figure 6, the first position P1 of the first holder 31a may be any position on the first main surface 91m. 【0033】 (Optional additional configuration) Next, with reference to Figures 1 to 34, optional additional configurations that can be adopted in the method for determining the positions of three or more holders in the first embodiment will be described. 【0034】 (Determination of the 4th position P4) As illustrated in Figure 7, in the fourth step ST4, the position of the fourth holder 31d that holds the first workpiece 91 (hereinafter referred to as "fourth position P4") may be determined based on the first shape S1 of the first workpiece 91, the first length L1 from the first holder 31a, the second length L2 from the second holder 31b, and the third length L3 from the third holder 31c. The fourth step ST4 is a fourth position determination step. The fourth position determination step (fourth step ST4) is performed by the computer 60. In the example shown in Figure 7, the fourth position determination step (fourth step ST4) is performed after the third position determination step (third step ST3) is performed. 【0035】 As illustrated in Figure 7, the fourth position determination step (in other words, the step of determining the fourth position P4 of the fourth holder 31d) may include the computer 60 determining the fourth position P4 such that the condition is met that the entire workpiece holding surface of the fourth holder 31d is in contact with the first workpiece 91. 【0036】 (Determination of the 5th position P5) As illustrated in Figure 8, in the fifth step ST5, the position of the fifth holder 31e that holds the first workpiece 91 (hereinafter referred to as "fifth position P5") may be determined based on the first shape S1 of the first workpiece 91, the first length L1 from the first holder 31a, the second length L2 from the second holder 31b, the third length L3 from the third holder 31c, and the fourth length L4 from the fourth holder 31d. The fifth step ST5 is a fifth position determination step. The fifth position determination step (fifth step ST5) is performed by the computer 60. In the example shown in Figure 8, the fifth position determination step (fifth step ST5) is performed after the fourth position determination step (fourth step ST4) is performed. 【0037】 As illustrated in Figure 8, the fifth position determination step (in other words, the step of determining the fifth position P5 of the fifth holder 31e) may include the computer 60 determining the fifth position P5 such that the condition is met that the entire workpiece holding surface of the fifth holder 31e is in contact with the first workpiece 91. 【0038】 In this specification, "N" is defined as any natural number greater than or equal to 2. For example, "N" may be 2, 3, 4, 5, 6, 7, 8, or 9. "N" may also be greater than or equal to 10. 【0039】 The method for determining the positions of three or more holders in the first embodiment includes the step of determining the position of the "N+1" holder that holds the first workpiece 91, after the positions of "N" holders have been determined to be in positions where the first workpiece 91 can be held. The step of determining the position of the "N+1" holder includes determining the position of the "N+1" holder such that the minimum length from each of the already positioned "N" holders to the "N+1" holder is substantially maximized. That is, when the determined position of the "N+1" holder is defined as the "N+1" position, the length from the holder closest to the "N+1" position among the already positioned N holders to the "N+1" position is greater than the minimum length from the arbitrary position to the already positioned N holders when the "N+1" holder is positioned at an arbitrary position different from the "N+1" position that can hold the first workpiece 91. 【0040】 For example, when N=3, the method for determining the positions of three or more holders in the first embodiment includes the step of determining the position of a fourth holder 31d that holds the first workpiece 91, after the positions of the three holders have been determined to be in positions capable of holding the first workpiece 91 (see Figure 7). The step of determining the position of the fourth holder 31d includes determining the position of the fourth holder 31d such that the minimum length from each of the three already positioned holders (31a, 31b, 31c) to the fourth holder 31d is substantially maximized. In other words, as illustrated in Figure 7, when the determined position of the fourth retainer 31d is defined as the fourth position P4, the length from the retainer closest to the fourth position P4 among the three already positioned retainers (31a, 31b, 31c) (in the example shown in Figure 7, the retainer closest to the fourth position P4 is the first retainer 31a) to the fourth position P4 is greater than the minimum length from the arbitrary position to the three already positioned retainers (31a, 31b, 31c) when the fourth retainer 31d is positioned at an arbitrary position different from the fourth position P4 and capable of holding the first workpiece 91. 【0041】 (First position P1 of the first retainer 31a) In the example shown in Figure 9, the centroid position G1 of the first workpiece 91 is outside the outer edge of the first workpiece 91. In this case, the first position P1 of the first holder 31a that holds the first workpiece 91 may be determined to be a position near the centroid position G1. More specifically, determining the first position P1 of the first holder 31a based on the centroid position G1 of the first workpiece 91 may include determining the first position P1 of the first holder 31a to be a position near the centroid position G1 of the first workpiece 91. For example, determining the first position P1 of the first holder 31a may include determining the first position P1 of the first holder 31a to be a position on the first main surface 91m that is substantially closest to the centroid position G1 of the first workpiece 91. 【0042】 In the example shown in Figure 9, the position A2 on the first main surface 91m closest to the center of gravity G1 is on the edge 91e of the first workpiece 91. If the first holder 31a is placed on the edge 91e, a portion of the first holder 31a will protrude from the first workpiece 91. Therefore, in order to prevent a portion of the first holder 31a from protruding from the first workpiece 91, the "position substantially closest to the center of gravity G1" is not the aforementioned position A2 itself, but rather a vicinity of the aforementioned position A2. 【0043】 As illustrated in Figure 9, the first position determination step (in other words, the step of determining the first position P1 of the first holder 31a) may include the computer 60 determining the first position P1 such that the condition is met that the entire workpiece holding surface of the first holder 31a is in contact with the first workpiece 91. 【0044】 (First example of determining the second position P2) In the example shown in Figure 10, the second positioning step (second step ST2) includes determining the second position P2 of the second holder 31b such that the linear distance between the first holder 31a and the second holder 31b is substantially maximized. 【0045】 (Second example of determining the second position P2) As illustrated in Figure 13, the second position determination step (second step ST2) may include determining the second position P2 of the second holder 31b such that the shortest path PA1 (in Figure 13, the shortest path PA1 is shown by a thick line) on the first main surface 91m from the first holder 31a to the second holder 31b is substantially maximized. 【0046】 As illustrated in Figure 13, if the first workpiece 91 has an opening OP, the first length L1 from the first holder 31a may be a length that bypasses the opening OP. The opening OP may be a notch CT, a slit SL (see Figure 24), or a hole HP (see Figure 24). In this specification, the term opening OP encompasses notches CT, slits SL, and holes HP. 【0047】 If the first length L1 is the length that bypasses the opening OP, the presence of the opening OP will be taken into consideration when determining the second position P2 of the second retainer 31b. More specifically, unlike the case where the first length L1 from the first retainer 31a is uniquely the straight-line distance from the first retainer 31a (see Figure 10), the presence or absence of a region FR that is prone to bending due to the presence of the opening OP will be taken into consideration when determining the second position P2 of the second retainer 31b. 【0048】 Furthermore, by bypassing the opening OP, the second position P2 of the second holder 31b is determined to be a position suitable for holding the first workpiece 91 having the opening OP. For example, the second position P2 is prevented from overlapping the opening OP of the first workpiece 91. 【0049】 As illustrated in Figure 13, if the first workpiece 91 has a notch CT, the first length L1 from the first holder 31a may be a length that bypasses the notch CT. As illustrated in Figure 24, if the first workpiece 91 has a slit SL, the first length L1 from the first holder 31a may be a length that bypasses the slit SL. As illustrated in Figure 24, if the first workpiece 91 has a hole HP, the first length L1 from the first holder 31a may be a length that bypasses the hole HP. 【0050】 This allows the second position P2 to be determined after the first position P1, and the second holder 31b to be positioned at a location where the first workpiece 91 is likely to deflect, without depending on the operator's experience. 【0051】 (First example of determining the third position P3) In the example shown in Figure 11, the step of determining the third position P3 includes determining the third position P3 such that the smaller of the length from the first position P1 to the third position P3 and the length from the second position P2 to the third position P3 is substantially maximized. 【0052】 More specifically, as illustrated in Figure 11, in this specification, the value indicating the length from the first retainer 31a to the third retainer 31c is defined as the first value V1. The value indicating the length from the second retainer 31b to the third retainer 31c is defined as the second value V2. Furthermore, the smaller of the first value V1 and the second value V2 is defined as the third value. 【0053】 In the example shown in Figure 11, the first value V1, which indicates the length from the first retainer 31a to the third retainer 31c, is the value representing the straight-line distance between the first retainer 31a and the third retainer 31c. Also in the example shown in Figure 11, the second value V2, which indicates the length from the second retainer 31b to the third retainer 31c, is the value representing the straight-line distance between the second retainer 31b and the third retainer 31c. 【0054】 In the example shown in Figure 11, the step of determining the third position P3 includes determining the third position P3 such that the above-mentioned third value (in other words, the smaller of the first value V1 and the second value V2) is substantially maximized. When the third value is substantially maximized, sufficient distance is ensured between the first position P1 and the third position P3, and sufficient distance is ensured between the second position P2 and the third position P3. Therefore, the first workpiece 91 can be stably held using the first holder 31a located at the first position P1, the second holder 31b located at the second position P2, and the third holder 31c located at the third position P3. 【0055】 (Second example of determining the third position P3) The fourth value is defined as the sum of the first value V1 (see Figure 11) and the second value V2 (see Figure 11). The step of determining the third position P3 may include determining the third position P3 such that the above-mentioned fourth value is substantially maximized. 【0056】 In the example shown in Figure 12, the sum of the length LN1 from the first position P1 to the first candidate position CA1 and the length LN2 from the second position P2 to the first candidate position CA1 (LN1 + LN2) is greater than the sum of the length LN3 from the first position P1 to the second candidate position CA2 and the length LN4 from the second position P2 to the second candidate position CA2 (LN3 + LN4). Also, the sum of the length LN1 from the first position P1 to the first candidate position CA1 and the length LN2 from the second position P2 to the first candidate position CA1 (LN1 + LN2) is greater than the sum of the length LN5 from the first position P1 to the third candidate position CA3 and the length LN6 from the second position P2 to the third candidate position CA3 (LN5 + LN6). 【0057】 Therefore, the step of determining the third position P3 includes determining the first candidate position CA1 to be the third position P3 such that the fourth value described above is substantially maximized. 【0058】 (Third example of determining the third position P3) In the example shown in Figure 14, the step of determining the third position P3 includes determining the third position P3 such that the smaller of the length from the first position P1 to the third position P3 and the length from the second position P2 to the third position P3 is substantially maximized. 【0059】 More specifically, as illustrated in Figure 14, the value representing the length from the first retainer 31a to the third retainer 31c is defined as the first value V1. The value representing the length from the second retainer 31b to the third retainer 31c is defined as the second value V2. Furthermore, the smaller of the first value V1 and the second value V2 is defined as the third value. 【0060】 In the example shown in Figure 14, the first value V1, which indicates the length from the first retainer 31a to the third retainer 31c, is the value indicating the length of the shortest path PA2 on the first main surface 91m from the first retainer 31a to the third retainer 31c (in Figure 14, the shortest path PA2 is shown by a dashed line segment). In the example shown in Figure 14, the second value V2, which indicates the length from the second retainer 31b to the third retainer 31c, is the value indicating the length of the shortest path PA3 on the first main surface 91m from the second retainer 31b to the third retainer 31c (in Figure 14, the shortest path PA3 is shown by a thick line). 【0061】 In the example shown in Figure 14, the step of determining the third position P3 includes determining the third position P3 such that the above-mentioned third value (in other words, the smaller of the first value V1 and the second value V2) is substantially maximized. When the third value is substantially maximized, sufficient length is ensured between the first position P1 and the third position P3, and sufficient length is ensured between the second position P2 and the third position P3. Therefore, the first workpiece 91 can be stably held using the first holder 31a located at the first position P1, the second holder 31b located at the second position P2, and the third holder 31c located at the third position P3. 【0062】 (Fourth example of determining the third position P3) The fourth value is defined as the sum of the first value V1 (see Figure 14) and the second value V2 (see Figure 14). The step of determining the third position P3 may include determining the third position P3 such that the above-mentioned fourth value is substantially maximized. 【0063】 In the example shown in Figure 15, the sum of the length LM1 of the shortest path on the first main surface 91m from the first position P1 to the first candidate position CA1 and the length LM2 of the shortest path on the first main surface 91m from the second position P2 to the first candidate position CA1 (shown by a thick line in Figure 15) (LM1 + LM2) is greater than the sum of the length LM3 of the shortest path on the first main surface 91m from the first position P1 to the second candidate position CA2 and the length LM4 of the shortest path on the first main surface 91m from the second position P2 to the second candidate position CA2 (LM3 + LM4). Furthermore, the sum of the length LM1 of the shortest path on the first main surface 91m from the first position P1 to the first candidate position CA1 and the length LM2 of the shortest path on the first main surface 91m from the second position P2 to the first candidate position CA1 (LM1 + LM2) is greater than the sum of the length LM5 of the shortest path on the first main surface 91m from the first position P1 to the third candidate position CA3 and the length LM6 of the shortest path on the first main surface 91m from the second position P2 to the third candidate position CA3 (LM5 + LM6). 【0064】 Therefore, the step of determining the third position P3 includes determining the first candidate position CA1 to be the third position P3 such that the fourth value described above is substantially maximized. 【0065】 (Map 1 MP1) In the example shown in Figure 16, the first position determination step (first step ST1) includes determining the first position P1 of the first holder 31a based on the center of gravity position G1 of the first workpiece 91. Alternatively, the first position P1 of the first holder 31a may be determined independently of the center of gravity position G1 of the first workpiece 91. The coordinates of the determined first position P1 (hereinafter referred to as "first coordinates PC1") may be displayed on the display 67. The first coordinates PC1 may also be stored in the memory 62. In the example shown in Figure 16, the first position P1 indicates the relative position of the first holder 31a with respect to at least one workpiece, including the first workpiece 91. 【0066】 As illustrated in Figure 16, the method for determining the positions of three or more holders in the first embodiment may include the step of generating a first map MP1 showing the distribution of a first length L1 from the first holder 31a. The step of generating the first map MP1 is performed by the computer 60 (more specifically, the arithmetic unit 63 of the computer 60). The method for determining the positions of three or more holders in the first embodiment may also include the step of displaying the generated first map MP1 on a display 67 (more specifically, the display 67 of the computer 60). Alternatively, the step of displaying the first map MP1 on the display 67 may be omitted. 【0067】 In the example shown in Figure 16, the distribution of the first length L1 from the first retainer 31a is indicated by the numbers on each face element EL. It goes without saying that the display of these numbers may be omitted. In figures other than Figure 16, the display of the numbers on each face element EL may also be omitted. 【0068】 As illustrated in Figure 16, the second position determination step (second step ST2) may include determining the second position P2 of the second holder 31b based on the first map MP1. More specifically, the computer 60 (more specifically, the arithmetic unit 63 of the computer 60) may determine the second position P2 of the second holder 31b based on the first map MP1. The coordinates of the determined second position P2 (hereinafter referred to as "second coordinates PC2") may be displayed on the display 67 (see Figure 17). The second coordinates PC2 may also be stored in the memory 62. In the example shown in Figure 17, the second position P2 indicates the relative position of the second holder 31b with respect to at least one workpiece, including the first workpiece 91. 【0069】 In the example shown in Figure 16, the first length L1 from the first holder 31a is the length that bypasses the opening OP of the first workpiece 91. Furthermore, the distribution of the first length L1 from the first holder 31a is the distribution of the lengths of the shortest paths along the first main surface 91m, starting from the first holder 31a. When the first length L1 is the length that bypasses the opening OP, the presence of the opening OP is taken into consideration when determining the second position P2 of the second holder 31b. 【0070】 As illustrated in Figure 16, if the first workpiece 91 has a notch CT, the first length L1 from the first holder 31a may be a length that bypasses the notch CT. As illustrated in Figure 25, if the first workpiece 91 has a slit SL, the first length L1 from the first holder 31a may be a length that bypasses the slit SL. As illustrated in Figure 25, if the first workpiece 91 has a hole HP, the first length L1 from the first holder 31a may be a length that bypasses the hole HP. 【0071】 Alternatively, as illustrated in Figure 22, the first length L1 from the first holder 31a may be a length that does not bypass the opening OP of the first workpiece 91. More specifically, the distribution of the first length L1 from the first holder 31a may be a distribution of straight-line distances centered on the first holder 31a. 【0072】 When the first map MP1 is generated, the second position P2 of the second holder 31b can be efficiently determined based on the first map MP1. When the first map MP1 is displayed, the operator can easily grasp the positional relationship between the first position P1 of the first holder 31a and the second position P2 of the second holder 31b. 【0073】 As illustrated in Figure 16 (or Figure 22), the method for determining the positions of three or more holders in the first embodiment may include the step of dividing the shape of the first workpiece 91 (in other words, the first shape S1) into a plurality of face elements EL. Each of the plurality of face elements EL is, for example, a square shape. Alternatively, each of the plurality of face elements EL may be a sector shape, a circle shape, or any other shape. When the first shape S1 is divided into a plurality of face elements EL, the generation of the first map MP1 is made more efficient. 【0074】 In the example shown in Figure 16, for the sake of clarity, the size of each face element EL is larger than the size of the first holder 31a. Needless to say, for more accurate calculations, the size of each face element EL may be smaller than the size of the first holder 31a. The step of dividing the first shape S1 of the first workpiece 91 into a plurality of face elements EL may include dividing the first shape S1 into 100 or more face elements EL, dividing the first shape S1 into 1,000 or more face elements EL, dividing the first shape S1 into 10,000 or more face elements EL, or dividing the first shape S1 into 1,000,000 or more face elements EL. 【0075】 In the example shown in Figure 16 (or Figure 22), the first map MP1 is generated based on the length from the first retainer 31a (more specifically, the first position P1) to each of the multiple face elements EL. As illustrated in Figure 16, the first map MP1 may also be generated based on the length of the shortest path along the first principal surface 91m from the first retainer 31a (more specifically, the first position P1) to each of the multiple face elements EL. Alternatively, as illustrated in Figure 22, the first map MP1 may be generated based on the straight-line distance from the first retainer 31a to each of the multiple face elements EL. 【0076】 As illustrated in Figure 16 (or Figure 22), the length from the first holder 31a to each of the multiple face elements EL may be derived by incrementing by a predetermined amount (for example, by 1) each time a face element is crossed. 【0077】 As illustrated in Figure 16, the method for determining the positions of three or more retainers in the first embodiment (more specifically, the step of displaying the first map MP1 on the display 67) may include displaying a plurality of face elements EL on the display 67 in different colors according to the length from the first retainer 31a to each of the plurality of face elements EL. In the dot hatching in Figure 16, areas with a high density of dots may show a first color (e.g., red). In the dot hatching in Figure 16, areas with a low density of dots may show a second color (e.g., blue). The first color may be white (or black) and the second color may be black (or white). The first length L1 from the first retainer 31a may be represented by the shade of color. 【0078】 In the example shown in Figure 16, the operator can easily visually identify areas of the first workpiece 91 that are prone to bending. 【0079】 As illustrated in Figure 18, the step of determining the second position P2 may include determining the second position P2 of the second holder 31b based on the first shape S1 of the first workpiece 91, the first length L1 from the first holder 31a, and the condition of the surrounding area of ​​each point on the first shape S1 (for example, based on the condition of the surrounding area within a predetermined distance from each point on the first shape S1). 【0080】 In the example shown in Figure 18, the surrounding region RG1 of the first face element EL1 on the first shape S1 (more specifically, the surrounding region RG1 within a predetermined distance from the first face element EL1) includes a region RT that is not the first main surface 91m of the first workpiece 91. On the other hand, the surrounding region RG2 of the second face element EL2 on the first shape S1 (more specifically, the surrounding region RG2 within a predetermined distance from the second face element EL2) is entirely filled with the region that constitutes the first main surface 91m of the first workpiece 91. When the holder is placed on the second face element EL2, the area in which the holder can stably hold the first workpiece 91 without protruding from the first workpiece 91 is larger compared to when the holder is placed on the first face element EL1. Therefore, if all other conditions are the same, it is preferable to place the holder on the second face element EL2. 【0081】 In the example shown in Figure 18, the second position P2 of the second holder 31b is determined based on a first map MP1 showing the distribution of a first length L1 from the first holder 31a and an auxiliary map MA showing the conditions of the surrounding area of ​​each point on the first shape S1. As illustrated in Figure 18, the auxiliary map MA may be a map showing the distribution of the number of face primes within a predetermined distance (in the example shown in Figure 18, the predetermined distance is "2") from each point on the first shape S1. As illustrated in Figure 18, the second position P2 of the second holder 31b may also be determined based on a composite map MB obtained by combining the first map MP1 and the auxiliary map MA. 【0082】 As illustrated in Figure 18, the step of determining the second position P2 may include determining the second position P2 of the second holder 31b based on the first shape S1 of the first workpiece 91, the first length L1 from the first holder 31a, and the amount of surface elements that are within a predetermined distance from each point on the first shape S1 and constitute the first shape S1. 【0083】 (2nd map MP2) As illustrated in Figure 17 (or Figure 23), the method for determining the positions of three or more holders in the first embodiment may include a step of generating a second map MP2 which combines the distribution of a first length L1 from the first holder 31a and the distribution of a second length L2 from the second holder 31b. The step of generating the second map MP2 is performed by the computer 60 (more specifically, the arithmetic unit 63 of the computer 60). The method for determining the positions of three or more holders in the first embodiment may also include a step of displaying the generated second map MP2 on a display 67 (more specifically, the display 67 of the computer 60). Alternatively, the step of displaying the second map MP2 on the display 67 may be omitted. 【0084】 As illustrated in Figure 17 (or Figure 23), the third position determination step (third step ST3) may include determining the third position P3 of the third holder 31c based on the second map MP2. More specifically, the computer 60 (more specifically, the arithmetic unit 63 of the computer 60) may determine the third position P3 of the third holder 31c based on the second map MP2. The coordinates of the determined third position P3 (hereinafter referred to as "third coordinate PC3") may be displayed on the display 67 (see Figure 19). The third coordinate PC3 may also be stored in the memory 62. In the example shown in Figure 19, the third position P3 indicates the relative position of the third holder 31c with respect to at least one workpiece, including the first workpiece 91. 【0085】 In the example shown in Figure 17, the first length L1 from the first holder 31a is the length that bypasses the opening OP of the first workpiece 91. Furthermore, the distribution of the first length L1 from the first holder 31a is the distribution of the lengths of the shortest paths along the first main surface 91m, starting from the first holder 31a. In the example shown in Figure 17, the numbers attached to each of the multiple face elements EL that are closer to the first holder 31a than to the second holder 31b indicate the distribution of the first length L1 from the first holder 31a. 【0086】 In the example shown in Figure 17, the distribution of the second length L2 from the second retainer 31b is the distribution of the lengths of the shortest paths along the first main surface 91m, starting from the second retainer 31b. In the example shown in Figure 17, the numbers attached to each of the multiple face elements EL that are closer to the second retainer 31b than to the first retainer 31a indicate the distribution of the second length L2 from the second retainer 31b. 【0087】 As illustrated in Figure 17, if the first workpiece 91 has an opening OP, the second length L2 from the second holder 31b may be a length that bypasses the opening OP. The opening OP may be a notch, a hole, or a slit. As illustrated in Figure 26, if the first workpiece 91 has a slit SL, the second length L2 from the second holder 31b may be a length that bypasses the slit SL. As illustrated in Figure 26, if the first workpiece 91 has a hole HP, the second length L2 from the second holder 31b may be a length that bypasses the hole HP. 【0088】 When the value representing the length from the first retainer 31a to the third retainer 31c is defined as the first value V1 (see Figure 11 or Figure 14), the value representing the length from the second retainer 31b to the third retainer 31c is defined as the second value V2 (see Figure 11 or Figure 14), and the smaller of the first value V1 and the second value V2 is defined as the third value, the step of determining the third position P3 of the third retainer 31c may include determining the third position P3 based on the second map MP2 such that the above-mentioned third value is substantially maximized. 【0089】 In the example shown in Figure 17, for each of the multiple face elements EL, the minimum of the values ​​representing the first length L1 and the second length L2 is adopted as the third value described above. Furthermore, the second map MP2, which combines the distribution of the first length L1 and the distribution of the second length L2, is the distribution of the said third value (in the example shown in Figure 17, the distribution of the said third value is indicated by the numbers on each face element EL). In the example shown in Figure 17, determining the third position P3 based on the second map MP2 involves determining the third position P3 to be the position that substantially corresponds to the face element EL where the third value is maximum in the distribution of the third value. 【0090】 Alternatively, when the value representing the length from the first retainer 31a to the third retainer 31c is defined as the first value V1 (see Figure 11 or Figure 14), the value representing the length from the second retainer 31b to the third retainer 31c is defined as the second value V2 (see Figure 11 or Figure 14), and the sum of the first value V1 and the second value V2 is defined as the fourth value, the step of determining the third position P3 of the third retainer 31c may include determining the third position P3 based on the second map MP2 such that the above-mentioned fourth value is substantially maximized. 【0091】 In the example shown in Figure 23, for each of the multiple face elements EL, the sum of the value representing the first length L1 and the value representing the second length L2 is adopted as the fourth value described above. Furthermore, the second map MP2, which combines the distribution of the first length L1 and the distribution of the second length L2, is the distribution of the fourth value (in the example shown in Figure 23, the distribution of the fourth value is indicated by the numbers on each face element EL). In the example shown in Figure 23, determining the third position P3 based on the second map MP2 involves determining the third position P3 to be the position that substantially corresponds to the face element EL where the fourth value is maximized in the distribution of the fourth value. When the fourth value is substantially maximized, sufficient length is ensured between the first position P1 and the third position P3, and between the second position P2 and the third position P3. Therefore, the first workpiece 91 can be stably held using the first holder 31a positioned at the first position P1, the second holder 31b positioned at the second position P2, and the third holder 31c positioned at the third position P3. 【0092】 As illustrated in Figure 17, the method for determining the positions of three or more retainers in the first embodiment (more specifically, the step of displaying the second map MP2 on the display 67) may include displaying the multiple face elements EL on the display 67 in different colors according to the length from each of the multiple face elements EL to the closer retainer of the first retainer 31a and the second retainer 31b. In the dot hatching in Figure 17, areas with a high density of dots may show a first color (e.g., red). In the dot hatching in Figure 17, areas with a low density of dots may show a second color (e.g., blue). The first color may be white (or black) and the second color may be black (or white). The shade of color may represent the length from the closer retainer of the first retainer 31a and the second retainer 31b. 【0093】 The step of determining the third position P3 may include determining the third position P3 of the third holder 31c based on the first shape S1 of the first workpiece 91, the first length L1 from the first holder 31a, the second length L2 from the second holder 31b, and the condition of the surrounding area of ​​each point on the first shape S1 (for example, based on the condition of the surrounding area within a predetermined distance from each point on the first shape S1). For example, the third position P3 of the third holder 31c may be determined based on the second map MP2 described above and an auxiliary map MA (see Figure 18) showing the condition of the surrounding area of ​​each point on the first shape S1. 【0094】 Furthermore, the algorithm for generating the second map MP2, which combines the distribution of the first length L1 and the distribution of the second length L2, is not limited to the examples shown in Figures 17 and 23. For example, when generating the second map MP2, the weighting assigned to the first length L1 from the first holder 31a may differ from the weighting assigned to the second length L2 from the second holder 31b. 【0095】 Furthermore, as illustrated in Figure 27, in the distribution of the first length L1 from the first holder 31a, when crossing the slit line SS, the value of the first length L1 from the first holder 31a may be configured to be added and corrected by a predetermined value (in the example shown in Figure 27, the predetermined value is 2). Similarly, in the distribution of the second length L2 from the second holder 31b, when crossing the slit line SS, the value of the second length L2 from the second holder 31b may be configured to be added and corrected by a predetermined value. In the example shown in Figure 27, even when it is unclear where the joint portion J (see Figure 24) is located on the slit line SS, the distribution of the first length L1 can be created by considering the presence of the slit SL. 【0096】 Alternatively, or additionally, the first length L1 and the second length L2 may be weighted according to the local thickness of the first workpiece 91. In the example shown in Figure 16, the first length L1 from the first holder 31a to each of the multiple face elements EL is derived by incrementing by a predetermined amount (e.g., 1) each time a face element is crossed. If the first workpiece 91 includes a thick-walled region with a relatively thicker thickness and a thin-walled region with a relatively thinner thickness, the first length L1 from the first holder 31a to each of the multiple face elements EL may be derived by incrementing by a first predetermined amount (e.g., 1) each time a face element on the thick-walled region is crossed, and by incrementing by a second predetermined amount (e.g., 2) different from the first predetermined amount each time a face element on the thin-walled region is crossed. 【0097】 (3rd map MP3) As illustrated in Figure 19, the method for determining the positions of three or more holders in the first embodiment may include a step of generating a third map MP3 which is a combination of the distribution of a first length L1 from the first holder 31a, the distribution of a second length L2 from the second holder 31b, and the distribution of a third length L3 from the third holder 31c. The step of generating the third map MP3 is performed by the computer 60 (more specifically, the arithmetic unit 63 of the computer 60). The method for determining the positions of three or more holders in the first embodiment may also include a step of displaying the generated third map MP3 on a display 67 (more specifically, the display 67 of the computer 60). 【0098】 As illustrated in Figure 19, the fourth position determination step (fourth step ST4) may include determining the fourth position P4 of the fourth holder 31d based on the third map MP3. More specifically, the computer 60 (more specifically, the arithmetic unit 63 of the computer 60) may determine the fourth position P4 of the fourth holder 31d based on the third map MP3. 【0099】 As illustrated in Figure 19, in each of the multiple face elements EL, the minimum value among the values ​​representing the first length L1, the second length L2, and the third length L3 may be adopted as the fifth value. The third map MP3 may also be the distribution of the fifth value (in the example shown in Figure 19, the distribution of the fifth value is shown by the numbers on each face element EL). In the example shown in Figure 19, determining the fourth position P4 based on the third map MP3 may include determining the fourth position P4 to be a position that substantially corresponds to the face element EL where the fifth value is maximum in the distribution of the fifth value. The coordinates of the determined fourth position P4 (hereinafter referred to as "fourth coordinate PC4") may be displayed on the display 67 (see Figure 20). The fourth coordinate PC4 may also be stored in the memory 62. 【0100】 (Map 4, MP4) As illustrated in Figure 20, the method for determining the positions of three or more holders in the first embodiment may include a step of generating a fourth map MP4 which is a combination of the distribution of a first length L1 from the first holder 31a, the distribution of a second length L2 from the second holder 31b, the distribution of a third length L3 from the third holder 31c, and the distribution of a fourth length L4 from the fourth holder 31d. The step of generating the fourth map MP4 is performed by the computer 60 (more specifically, the arithmetic unit 63 of the computer 60). The method for determining the positions of three or more holders in the first embodiment may also include a step of displaying the generated fourth map MP4 on a display 67 (more specifically, the display 67 of the computer 60). 【0101】 As illustrated in Figure 20, the fifth position determination step (fifth step ST5) may include determining the fifth position P5 of the fifth holder 31e based on the fourth map MP4. More specifically, the computer 60 (more specifically, the arithmetic unit 63 of the computer 60) may determine the fifth position P5 of the fifth holder 31e based on the fourth map MP4. The coordinates of the determined fifth position P5 (hereinafter referred to as "fifth coordinate PC5") may be displayed on the display 67 (see Figure 21). The fifth coordinate PC5 may also be stored in the memory 62. 【0102】 As illustrated in Figure 20, in each of the multiple face elements EL, the minimum value among the values ​​representing the first length L1, the second length L2, the third length L3, and the fourth length L4 may be adopted as the sixth value. Furthermore, the fourth map MP4 may be the distribution of the sixth value (in the example shown in Figure 20, the distribution of the sixth value is indicated by the numbers on each face element EL). Moreover, determining the fifth position P5 based on the fourth map MP4 may include determining the fifth position P5 to be a position that substantially corresponds to the face element EL where the sixth value is maximum in the distribution of the sixth value. 【0103】 The method for determining the positions of three or more holders in the first embodiment may include a step of deriving the number of holders 31 used to hold the first workpiece 91 based on the distribution of lengths from each position of the plurality of holders 31. The number of holders 31 used to hold the first workpiece 91 may be less than the total number of holders 31 in the workpiece transfer device 10. 【0104】 In this specification, "K" is defined as any natural number greater than or equal to 3. For example, "K" could be 3, 4, 5, 6, 7, 8, or 9. "K" may also be greater than or equal to 10. 【0105】 The method for determining the positions of three or more holders in the first embodiment may include determining the number of holders 31 used to hold the first workpiece 91 to be "K" if, after determining the positions of "K" holders among the plurality of holders 31, it is not possible to determine the position of the "K+1"th holder (in other words, the "K+1"th holder) such that the length from each of the "K" holders' positions is greater than or equal to a preset first threshold. For example, in the example shown in Figure 21, assume that the first threshold is "7". In the example shown in Figure 23, after determining the positions of "5" holders, it is not possible to determine the position of the "6th" holder (in other words, the 6th holder) such that the length from each of the "5" holders' positions is greater than or equal to a preset first threshold (i.e., "7"). Therefore, even though the total number of holders in the workpiece transfer device 10 is 6 or more, the number of holders 31 used to hold the first workpiece 91 may be determined to be "5". 【0106】 Furthermore, if the workpiece is a small workpiece, the number of holders 31 used to hold the small workpiece may be one or two. For example, the number of holders 31 used to hold the small workpiece 94 shown in Figure 42 may be one. If the first workpiece is a small workpiece 94, the number of holders 31 used to hold the first workpiece may be one or two. If the second workpiece is a small workpiece 94, the number of holders 31 used to hold the second workpiece may be one or two. 【0107】 Alternatively, regardless of the length distribution of each of the multiple holders 31 from their respective positions, all of the holders of the workpiece transfer device 10 may be configured to be used for holding the first workpiece 91. 【0108】 As illustrated in Figures 16, 17, 19, 20, and 21, the method for determining the positions of three or more retainers in the first embodiment may include the computer 60 automatically determining the first position P1 of the first retainer 31a, the computer 60 automatically determining the second position P2 of the second retainer 31b, and the computer 60 automatically determining the third position P3 of the third retainer 31c. Furthermore, the method for determining the positions of three or more retainers in the first embodiment may also include the computer 60 automatically determining the fourth position P4 of the fourth retainer 31d, and the computer 60 automatically determining the fifth position P5 of the fifth retainer 31e. 【0109】 When the number of holders 31 used to hold the first workpiece 91 is "K", the method for determining the positions of three or more holders in the first embodiment may include the computer 60 automatically determining the positions of the "K" holders 31. If the positions of all holders 31 used to hold the first workpiece 91 are automatically determined by the computer 60, the workload of the operator required to determine the positions of the holders is reduced. 【0110】 (Work 1, 91) The first workpiece 91 is, for example, a plate-shaped workpiece 911. The first workpiece 91 (more specifically, the plate-shaped workpiece 911) is, for example, made of metal. The first workpiece 91 (more specifically, the plate-shaped workpiece 911) may be made of resin or other material. The first workpiece 91 (more specifically, the plate-shaped workpiece 911) is held by magnetic force (or vacuum attraction force). 【0111】 The plate-shaped workpiece 911 may be a thick plate. The thickness of the plate-shaped workpiece 911 may be, for example, 1 cm or more, 2 cm or more, or 3 cm or more. Alternatively, the plate-shaped workpiece 911 may be a thin plate. The plate-shaped workpiece 911 may be a heavy workpiece. The mass of the plate-shaped workpiece 911 may be, for example, 5 kg or more, or 10 kg or more. Alternatively, the plate-shaped workpiece 911 may be a lightweight workpiece. 【0112】 As illustrated in Figure 24, the first workpiece 91 may be a plate-shaped workpiece in which multiple parts PD are connected via joints J. In other words, the first workpiece 91 may be divisible into multiple parts PD. In the example shown in Figure 24, multiple slits SL are formed in the first workpiece 91. 【0113】 Alternatively, or additionally, the first workpiece 91 may have a hole portion HP. Alternatively, or additionally, the first workpiece 91 may have a notch portion CT. 【0114】 If the first workpiece 91 is a plate-shaped workpiece 911, the centroid position G1 of the first workpiece 91 may mean the centroid position of the first main surface 91m of the first workpiece 91 which is held by a plurality of holders 31. 【0115】 (Correction for the second position P2) In the example shown in Figure 28, the second position determination step (second step ST2) includes determining the second position P2 of the second holder 31b such that the length LT1 from the first holder 31a to the second holder 31b is substantially maximized. Furthermore, in the example shown in Figure 28, the second position P2 of the second holder 31b is determined without the additional condition that the entire workpiece holding surface of the second holder 31b is in contact with the first workpiece 91. 【0116】 In the example shown in Figure 28, the second retainer 31b positioned at the determined second position P2 overlaps with the hole HP of the first workpiece 91. In this case, the method for determining the positions of three or more retainers in the first embodiment may include a step of correcting the second position P2 (hereinafter referred to as the "correction step") such that the length LT1 from the first retainer 31a to the second retainer 31b is shortened until the overlap between the second retainer 31b and the hole HP is eliminated. Figure 28 shows the second position P2 before correction as well as the corrected second position P2'. This correction step may be performed automatically by a computer 60 or by an operator. 【0117】 Furthermore, as illustrated in Figure 30, if the second position determination step (second step ST2) includes determining the second position P2 such that the entire workpiece holding surface of the second holder 31b is in contact with the first workpiece 91, the above-described correction step may be omitted. 【0118】 Referring to Figures 29 and 30, an example will be described in which the above-mentioned first position P1, second position P2, and third position P3 are determined such that the condition is met that the entire workpiece holding surface of the second holder 31b is in contact with the first workpiece 91. 【0119】 As illustrated in Figure 29, the method for determining the positions of three or more holders in the first embodiment may include a step of deriving an allowable region BR in the shape of the first workpiece 91 (in other words, the first shape S1) in which the placement of the holders is permitted. For example, the allowable region BR may be derived based on the edge EG of the first workpiece 91 and a predetermined margin distance MG. More specifically, the boundary of the allowable region BR may be set inward from the edge EG of the first workpiece 91 by a margin distance MG. The edge EG includes the outer edge of the first workpiece 91 and the outer edge of the hole HP of the first workpiece. The margin distance MG is set to a value greater than, for example, the radius of the workpiece holding surface of the first holder 31a (or the radius of the workpiece holding surface of the second holder 31b). 【0120】 The first position determination step (first step ST1) may include determining the first position P1 of the first holder 31a based on the allowable region BR. More specifically, the first position determination step (first step ST1) may include determining the first position P1 of the first holder 31a based on the center of gravity position G1 of the first workpiece 91 and the allowable region BR. 【0121】 The second position determination step (second step ST2) may include determining the second position P2 of the second holder 31b based on the allowable region BR, the first shape S1 of the first workpiece 91, and the first length L1 from the first holder 31a. 【0122】 As illustrated in Figure 30, the third position determination step (third step ST3) may include determining the third position P3 of the third holder 31c based on the allowable region BR, the first shape S1 of the first workpiece 91, the first length L1 from the first holder 31a, and the second length L2 from the second holder 31b. 【0123】 (Data acquisition process) As illustrated in Figure 31, the method for determining the positions of three or more holders in the first embodiment may include a step of acquiring shape data SH of the shape S containing the first workpiece 91 (hereinafter referred to as the "data acquisition step"). The data acquisition step includes the computer 60 acquiring shape data SH of the shape S containing the first workpiece 91. The data acquisition step may also include the computer 60 acquiring shape data SH of the shape S containing the first workpiece 91 from another computer such as a CAD / CAM device 18a (hereinafter referred to as the "second computer 18"). Alternatively, the computer 60 may acquire shape data SH of the shape S containing the first workpiece 91 based on input from an operator. The data acquisition step includes storing the shape data SH of the shape S containing the first workpiece 91 in memory 62. 【0124】 In the example shown in Figure 32, the method for determining the positions of three or more holders in the first embodiment includes a step (hereinafter referred to as the "extraction step") of extracting the shape of the first workpiece 91 (in other words, the first shape S1) and the shape of the second workpiece 92 separated from the first workpiece 91 (hereinafter referred to as the "second shape S2") from the acquired shape data SH. 【0125】 The extraction step may be performed if the shape S containing the first workpiece 91 contains at least two shapes that are separated from each other. For example, the extraction step may be performed if the shape S contains a point that cannot be reached from a point belonging to the shape S (for example, the centroid G of the shape S shown in Figure 32) without crossing the outer edge of the shape S. 【0126】 In the example shown in Figure 32, it is not possible to reach a point belonging to the second workpiece 92 from a point belonging to the first workpiece 91 without crossing the outer edge of the first workpiece 91. In this case, an extraction process (in other words, a process of extracting the first shape S1 and the second shape S2 from the acquired shape data SH) is performed. 【0127】 In the example shown in Figure 32, it is not possible to reach a point belonging to the first workpiece 91 from a point belonging to the second workpiece 92 (for example, the centroid G of the shape S that includes the first workpiece 91) without crossing the outer edge of the second workpiece 92. In this case, an extraction process (in other words, a process of extracting the first shape S1 and the second shape S2 from the acquired shape data SH) is performed. 【0128】 As illustrated in Figure 32, the method for determining the positions of three or more holders in the first embodiment may include a step of storing first shape data SH1, which represents the first shape S1 of the first workpiece 91, in the memory 62. The method for determining the positions of three or more holders in the first embodiment may also include a step of storing second shape data SH2, which represents the second shape S2 of the second workpiece 92, in the memory 62. 【0129】 As illustrated in Figure 32, a method for determining the positions of three or more holders in the first embodiment may include a step of deriving the centroid position G1 of the first workpiece 91 based on a first shape S1 (for example, based on a first shape S1 extracted from a shape S that includes the first workpiece 91 and the second workpiece 92). The first position determination step (first step ST1) may also include determining the first position P1 of the first holder 31a based on the derived centroid position G1 of the first workpiece 91. 【0130】 The method for determining the positions of three or more holders in the first embodiment may include a step of deriving the centroid position G2 of the second workpiece 92 based on a second shape S2 (for example, based on a second shape S2 extracted from a shape S that includes the first workpiece 91 and the second workpiece 92). Alternatively, the method for determining the positions of three or more holders in the first embodiment may include a step of determining the position of the holder that holds the second workpiece 92 based on the centroid position G2 of the second workpiece 92. 【0131】 As illustrated in Figure 31, the computer 60 may obtain data DT1 from the second computer 18 indicating the centroid G of the shape S containing the first workpiece 91. 【0132】 As illustrated in Figures 31 and 32, if the computer 60 obtains data DT1 indicating the centroid G of the shape S containing the first workpiece 91, and the centroid G is different from the centroid position G1 of the first workpiece 91, the computer 60 may derive the centroid position G1 of the first workpiece 91. If the shape S containing the first workpiece 91 is the shape of the first workpiece 91 itself, the computer 60 may consider the centroid G of the shape S containing the first workpiece 91 to be the centroid position G1 of the first workpiece 91. 【0133】 As illustrated in Figure 32, the second position determination step (second step ST2) may include determining the second position P2 of the second holder 31b that holds the first workpiece 91, based on the first shape S1 of the first workpiece 91 extracted from the shape S which includes the first workpiece 91 and the second workpiece 92, and the first length L1 from the first holder 31a. 【0134】 The extraction step described above (the step of extracting the first shape S1 and the second shape S2 separated from the first shape S1 from the acquired shape data SH) and the second position determination step described above (second step ST2) may be performed automatically by the computer 60. In this case, the workload of the operator required for the extraction of the first shape S1 and the second shape S2, and the workload of the operator required for the determination of the second position P2 are reduced. 【0135】 As illustrated in Figure 33, the method for determining the positions of three or more holders in the first embodiment may include, in addition to the steps of determining the first position P1 of the first holder 31a (in other words, the first position determination step), determining the second position P2 of the second holder 31b (in other words, the second position determination step), and determining the third position P3 of the third holder 31c (in other words, the third position determination step), the step of determining the positions of the multiple holders 31 that hold the second workpiece 92. 【0136】 The transport of the first workpiece 91 and the transport of the second workpiece 92 may be performed at different timings. In this case, the plurality of holders 31 that hold the second workpiece 92 may include the first holder 31a described above. Also, the plurality of holders 31 that hold the second workpiece 92 may include the second holder 31b and / or the third holder 31c described above. 【0137】 Alternatively, the transport of the first workpiece 91 and the transport of the second workpiece 92 may be performed simultaneously. In this case, the method for determining the positions of the three or more holders in the first embodiment includes the step of determining the position of at least one other holder such that the first workpiece 91 is held by the first holder 31a located at the first position P1, the second holder 31b located at the second position P2, and the third holder 31c located at the third position P3, and the second workpiece 92 is held by at least one other holder, separated from the first workpiece 91, simultaneously. 【0138】 More specifically, the position of the second group of holders 31-2 may be determined in addition to the determination of the first position P1, the second position P2, and the third position P3 described above, so that the first workpiece 91 is held by the first group of holders 31-1, which includes the first holder 31a, the second holder 31b, and the third holder 31c, and the second workpiece 92 is held by the second group of holders 31-2, simultaneously. 【0139】 In this specification, the first workpiece 91 may be a first plate-shaped workpiece, and the second workpiece 92 may be a second plate-shaped workpiece. Furthermore, the third workpiece 93, described later, may be a third plate-shaped workpiece. Each of the first workpiece 91, the second workpiece 92, and the third workpiece 93 may be made of a material that can be coupled to an electromagnet (more specifically, a ferromagnetic material), or it may be made of other materials. 【0140】 Since the procedure for determining the position of the first group of retainers 31-1 (in other words, the positions of multiple retainers including the first retainer 31a, the second retainer 31b, and the third retainer 31c) has already been explained, a repetitive explanation of the procedure for determining the position of the first group of retainers 31-1 will be omitted. 【0141】 The procedure for determining the position of the second group holder 31-2 is the same as the procedure for determining the position of the first group holder 31-1. Figure 33 shows the state after the positions of the first group holder 31-1 and the second group holder 31-2 have been determined. 【0142】 (Second embodiment) The workpiece transfer device 10A in the second embodiment will be described with reference to Figures 1 to 49. Figure 35 is a schematic diagram showing the workpiece transfer device 10A in the second embodiment. Figure 36 is a schematic diagram showing the computer 60. Figure 37 is a schematic perspective view showing the state in which a plurality of holders 31 are supported on the support 33. Figure 38 is a schematic perspective view showing how a plurality of attachments 3 can be removed from the support 33. Figure 39 is a schematic perspective view showing how the third workpiece 93 is transferred using a plurality of holders 31 arranged in the first layout LA1. Figure 40 is a schematic perspective view showing how the first workpiece 91 is transferred using a plurality of holders 31 arranged in the second layout LA2. Figure 41 is a schematic cross-sectional view showing the state in which the first attachment 3b and the second attachment 3c are attached to the support 33. Figure 42 is a schematic perspective view showing the workpiece transfer device 10A in the second embodiment. Figure 43 is a schematic perspective view showing a portion of the workpiece transfer device 10A in the second embodiment. Figure 44 is a schematic diagram showing how the control device 6 can control multiple control target devices. Figure 45 is a schematic diagram showing how the first position change mode M1-1 is executed. Figure 46 is a schematic diagram showing how the third transfer mode M2-3 is executed. Figure 47 is a schematic diagram showing how the first transfer mode M2-1 is executed. Figure 48 is a schematic diagram showing how the second transfer mode M2-2 is executed. In Figures 46 to 48, the multiple holders 31 and workpieces 9 located below the support 33 are shown by dashed lines to make it easier to understand the arrangement of the multiple holders 31 supported by the support 33 and the arrangement of the workpieces 9 held by the multiple holders 31. Figure 49 is a schematic perspective view showing how the first workpiece 91 and the second workpiece 92 are transferred simultaneously. 【0143】 The second embodiment will primarily describe the differences from the first embodiment. On the other hand, the second embodiment will omit repetitive explanations of matters already described in the first embodiment. Therefore, it goes without saying that even if not explicitly explained in the second embodiment, matters already described in the first embodiment can be applied to the second embodiment. Conversely, matters described in the second embodiment can also be adopted in the first embodiment. 【0144】 As illustrated in Figure 35, the workpiece transfer device 10A in the second embodiment includes (1) a plurality of holders 31 including a first holder 31a, a second holder 31b, and a third holder 31c; (2) a moving device 4 for moving a support 33 that supports the plurality of holders 31; (4) a memory 62 for storing the shape of the first workpiece 91 (more specifically, first shape data SH1 indicating the first shape S1 of the first workpiece 91); and (5) an arithmetic unit 63. 【0145】 The memory 62 and the arithmetic unit 63 may be included in the computer 60. In other words, the workpiece transport device 10A may be equipped with a computer 60 that includes the memory 62 and the arithmetic unit 63. 【0146】 As illustrated in Figure 16, the arithmetic unit 63 determines the first position P1 of the first holder 31a that holds the first workpiece 91 based on the first shape S1 of the first workpiece 91 (more specifically, based on the first shape data SH1 that shows the first shape S1 of the first workpiece 91). As illustrated in Figure 16, the coordinates of the determined first position P1 (in other words, the first coordinates PC1) may be displayed on the display 67. Alternatively, or additionally, the coordinates of the determined first position P1 (in other words, the first coordinates PC1) may be stored in the memory 62. 【0147】 As illustrated in Figure 16, the arithmetic unit 63 determines the second position P2 of the second holder 31b that holds the first workpiece 91 based on the first shape S1 of the first workpiece 91 (more specifically, the first shape data SH1 that shows the first shape S1) and the first length L1 from the first holder 31a. As illustrated in Figure 17, the coordinates of the determined second position P2 (in other words, the second coordinates PC2) may be displayed on the display 67. Alternatively, or additionally, the coordinates of the determined second position P2 (in other words, the second coordinates PC2) may be stored in the memory 62. 【0148】 As illustrated in Figure 17, the arithmetic unit 63 determines the third position P3 of the third holder 31c that holds the first workpiece 91 based on the first shape S1 of the first workpiece 91 (more specifically, the first shape data SH1 that shows the first shape S1), the first length L1 from the first holder 31a, and the second length L2 from the second holder 31b. As illustrated in Figure 19, the coordinates of the determined third position P3 (in other words, the third coordinates PC3) may be displayed on the display 67. Alternatively, or additionally, the coordinates of the determined third position P3 (in other words, the third coordinates PC3) may be stored in the memory 62. 【0149】 In the workpiece transfer device 10A of the second embodiment, the positions of the multiple holders 31, including the second holder 31b and the third holder 31c, can be determined without relying on the operator's experience. Therefore, the workload of the operator is reduced. In addition, since it is prevented that the arrangement of the multiple holders 31 will be in an inappropriate position, the first workpiece 91 can be transported stably. 【0150】 (Optional additional configuration) Next, with reference to Figures 1 to 49, optional additional configurations that can be adopted in the workpiece transfer device 10A in the second embodiment will be described. 【0151】 (Determination of the first position P1) As illustrated in Figure 16, the arithmetic unit 63 performs a first process U1 to determine the first position P1 of the first holder 31a that holds the first workpiece 91. In the example shown in Figure 16, the arithmetic unit 63 automatically determines the first position P1 based on the first shape S1 of the first workpiece 91 (more specifically, based on the first shape data SH1 that represents the first shape S1). Alternatively, as illustrated in Figure 3, the first position P1 of the first holder 31a may be determined based on input from an operator. The first process U1 may include storing the coordinates of the determined first position P1 (in other words, the first coordinates PC1) in the memory 62. 【0152】 As illustrated in Figure 16, the first process U1 may include determining the first position P1 of the first holder 31a based on the center of gravity position G1 derived from the first shape S1 of the first workpiece 91 (more specifically, the first shape data SH1 representing the first shape S1). The derivation of the center of gravity position G1 may be performed by the calculation unit 63 or by a second computer 18 such as a CAD / CAM device 18a (see Figure 31). 【0153】 If the first position P1 of the first holder 31a is determined based on the center of gravity position G1, the first holder 31a can be positioned at or near the center of gravity position G1. Therefore, when the first workpiece 91 is transported, the area near the center of gravity of the first workpiece 91 is prevented from bending downward, and the posture of the first workpiece 91 is stabilized when the first workpiece 91 is transported. 【0154】 However, as illustrated in Figure 6, the first position P1 of the first holder 31a may be determined without being based on the center of gravity position G1. 【0155】 (Derivation of the allowable region BR) As illustrated in Figure 29, the arithmetic unit 63 may derive an allowable region BR in the first shape S1 (in other words, the shape of the first workpiece 91) in which the placement of the holder is permitted. For example, the arithmetic unit 63 may derive an allowable region BR in which the placement of the holder is permitted based on the edge EG of the first workpiece 91 derived from the first shape S1 (more specifically, the first shape data SH1) and the margin distance MG stored in the memory 62. The boundary of the allowable region BR may be set inward from the edge EG of the first workpiece 91 by the margin distance MG. The edge EG includes the outer edge of the first workpiece 91 and the outer edge of the hole HP of the first workpiece. The margin distance MG is set to a value greater than, for example, the radius of the workpiece holding surface of the first holder 31a (or the radius of the workpiece holding surface of the second holder 31b). 【0156】 As illustrated in Figure 30, the calculation unit 63 may determine the first position P1 of the first holder 31a based on the centroid position G1 of the first workpiece 91 and the allowable region BR. For example, if the centroid position G1 of the first workpiece 91 is located in the allowable region BR, the calculation unit 63 may adopt the centroid position G1 of the first workpiece 91 as the first position P1. Alternatively, if the centroid position G1 of the first workpiece 91 is located outside the allowable region BR, the calculation unit 63 may adopt the point within the allowable region BR that is closest to the centroid position G1 as the first position P1. 【0157】 (Determination of the second position P2) As illustrated in Figure 16, the arithmetic unit 63 performs a second process U2 to determine the second position P2 of the second holder 31b that holds the first workpiece 91. As illustrated in Figures 4 and 13, the second process U2 may also include determining the second position P2 of the second holder 31b that holds the first workpiece 91 such that the length LT1 from the first holder 31a to the second holder 31b is substantially maximized. 【0158】 As illustrated in Figure 13, the computing unit 63 may determine the second position P2 of the second holder 31b such that the shortest path PA1 on the first main surface 91m from the first holder 31a to the second holder 31b is substantially maximized. 【0159】 As illustrated in Figure 16, the arithmetic unit 63 may generate a first map MP1 showing the distribution of the first length L1 from the first holder 31a. 【0160】 As illustrated in Figures 16 and 18, the second process U2 (in other words, the second process U2 that determines the second position P2) may include generating a first map MP1 and determining the second position P2 of the second holder 31b based on the first map MP1. The second process U2 may also include determining the second position P2 of the second holder 31b based on the first map MP1 and the allowable area BR (see Figure 29). Alternatively or additionally, the second process U2 may also include determining the second position P2 of the second holder 31b based on the first map MP1 and the auxiliary map MA (see Figure 18). The second process U2 may also include storing the coordinates of the determined second position P2 (in other words, the second coordinates PC2) in memory 62. 【0161】 In the example shown in Figure 16, the first length L1 from the first holder 31a is the length that bypasses the opening OP of the first workpiece 91. Furthermore, the distribution of the first length L1 from the first holder 31a is the distribution of the lengths of the shortest paths along the first main surface 91m, starting from the first holder 31a. When the first length L1 is the length that bypasses the opening OP, the presence of the opening OP is taken into consideration when determining the second position P2 of the second holder 31b. 【0162】 As illustrated in Figure 16, if the first workpiece 91 has a notch CT, the first length L1 from the first holder 31a may be a length that bypasses the notch CT. As illustrated in Figure 25, if the first workpiece 91 has a slit SL, the first length L1 from the first holder 31a may be a length that bypasses the slit SL. As illustrated in Figure 25, if the first workpiece 91 has a hole HP, the first length L1 from the first holder 31a may be a length that bypasses the hole HP. 【0163】 As illustrated in Figure 16, the arithmetic unit 63 may divide the shape of the first workpiece 91 (in other words, the first shape S1) into multiple surface elements EL. 【0164】 In the example shown in Figure 16, the first map MP1 is generated based on the length from the first retainer 31a to each of the multiple face elements EL. As illustrated in Figure 16, the first map MP1 may also be generated based on the length of the shortest path along the first principal surface 91m from the first retainer 31a to each of the multiple face elements EL. Alternatively, as illustrated in Figure 22, the first map MP1 may be generated based on the straight-line distance from the first retainer 31a to each of the multiple face elements EL. 【0165】 As illustrated in Figure 16, the length from the first holder 31a to each of the multiple face elements EL may be derived by incrementing by a predetermined amount (for example, by 1) each time a face element is crossed. 【0166】 As illustrated in Figure 16, the workpiece transfer device 10A (more specifically, the computer 60) in the second embodiment may include a display 67 that displays the first map MP1. The display 67 may display a plurality of face elements EL in different colors according to the length from the first holder 31a to each of the plurality of face elements EL. 【0167】 Since the first map MP1 and the multiple face elements EL have already been described in the first embodiment, further explanation of the first map MP1 and the multiple face elements EL will be omitted. 【0168】 (Determination of the third position P3) As illustrated in Figures 11 and 14, the arithmetic unit 63 performs a third process U3 to determine the third position P3 of the third holder 31c that holds the first workpiece 91. As illustrated in Figures 11 and 14, the third process U3 includes determining the third position P3 of the third holder 31c based on the first shape S1 of the first workpiece 91 (more specifically, first shape data SH1 representing the first shape S1), a first length L1 from the first holder 31a, and a second length L2 from the second holder 31b. 【0169】 In the examples shown in Figures 11 and 14, the step of determining the third position P3 includes determining the third position P3 such that the smaller of the length from the first position P1 to the third position P3 and the length from the second position P2 to the third position P3 is substantially maximized. 【0170】 More specifically, as illustrated in Figures 11 and 14, when the value representing the length from the first holder 31a to the third holder 31c is defined as the first value V1, the value representing the length from the second holder 31b to the third holder 31c is defined as the second value V2, and the smaller of the first value V1 and the second value V2 is defined as the third value, the third process U3 may include determining the third position P3 such that the above-mentioned third value (in other words, the smaller of the first value V1 and the second value V2) is substantially maximized. The third process U3 may also include determining the third position P3 such that the third value is substantially maximized based on the second map MP2 (see Figure 17). Alternatively, the third process U3 may include determining the third position P3 such that the sum of the first value V1 (see Figure 11 or 14) and the second value V2 (see Figure 11 or 14) is substantially maximized. 【0171】 As illustrated in Figure 17 (or Figure 23), the arithmetic unit 63 may generate a second map MP2 which is a combination of the distribution of the first length L1 from the first holder 31a and the distribution of the second length L2 from the second holder 31b. 【0172】 As illustrated in Figure 17 (or Figure 23), the third process U3 (in other words, the third process U3 that determines the third position P3) may include generating a second map MP2 and determining the third position P3 of the third holder 31c based on the second map MP2. The third process U3 may also include determining the third position P3 of the third holder 31c based on the second map MP2 and the allowable area BR (see Figure 29). Alternatively or additionally, the third process U3 may also include determining the third position P3 of the third holder 31c based on the second map MP2 and the auxiliary map MA (see Figure 18). The third process U3 may also include storing the coordinates of the determined third position P3 (in other words, the third coordinates PC3) in memory 62. 【0173】 As illustrated in Figure 17, the arithmetic unit 63 may display the second map MP2 on the display 67. As illustrated in Figure 17, the display 67 may display multiple face elements EL in different colors according to the length to the nearest of the first holder 31a and the second holder 31b. 【0174】 The algorithm by which the arithmetic unit 63 generates the second map MP2, which is a combination of the distribution of the first length L1 and the distribution of the second length L2, is not limited to the examples shown in Figures 17 and 23. 【0175】 Since the second map MP2 has already been described in the first embodiment, further explanation of the second map MP2 will be omitted. 【0176】 (Determination of the 4th position P4) As illustrated in Figure 19, the arithmetic unit 63 may perform a fourth process U4 to determine the fourth position P4 of the fourth holder 31d that holds the first workpiece 91. The fourth process U4 may include determining the fourth position P4 of the fourth holder 31d based on the first shape S1 of the first workpiece 91 (more specifically, first shape data SH1 that shows the first shape S1), a first length L1 from the first holder 31a, a second length L2 from the second holder 31b, and a third length L3 from the third holder 31c. 【0177】 As illustrated in Figure 19, the fourth process U4 may include generating a third map MP3 which is a combination of the distribution of a first length L1 from the first retainer 31a, the distribution of a second length L2 from the second retainer 31b, and the distribution of a third length L3 from the third retainer 31c. 【0178】 As illustrated in Figure 19, the fourth process U4 may include generating a third map MP3 and determining the fourth position P4 of the fourth holder 31d based on the third map MP3. The fourth process U4 may also include storing the coordinates of the determined fourth position P4 (in other words, the fourth coordinates PC4) in the memory 62. The fourth process U4 may also include displaying the third map MP3 on the display 67. 【0179】 Since the third map MP3 has already been described in the first embodiment, further explanation of the third map MP3 will be omitted. 【0180】 (Determination of the 5th position P5) As illustrated in Figure 20, the arithmetic unit 63 may perform a fifth process U5 to determine the fifth position P5 of the fifth holder 31e that holds the first workpiece 91. The fifth process U5 may include determining the fifth position P5 of the fifth holder 31e based on the first shape S1 of the first workpiece 91 (more specifically, first shape data SH1 that shows the first shape S1), a first length L1 from the first holder 31a, a second length L2 from the second holder 31b, a third length L3 from the third holder 31c, and a fourth length L4 from the fourth holder 31d. 【0181】 As illustrated in Figure 20, the fifth process U5 may also include generating a fourth map MP4 which is a combination of the distribution of a first length L1 from the first retainer 31a, the distribution of a second length L2 from the second retainer 31b, the distribution of a third length L3 from the third retainer 31c, and the distribution of a fourth length L4 from the fourth retainer 31d. 【0182】 As illustrated in Figure 20, the fifth process U5 may include generating a fourth map MP4 and determining the fifth position P5 of the fifth holder 31e based on the fourth map MP4. The fifth process U5 may also include storing the coordinates of the determined fifth position P5 (in other words, the fifth coordinates PC5) in the memory 62. The fifth process U5 may also include displaying the fourth map MP4 on the display 67. 【0183】 Since the fourth map MP4 has already been described in the first embodiment, further explanation of the fourth map MP4 will be omitted. 【0184】 (Determination of the "K" position) When "K" is defined as any natural number greater than or equal to 3 (for example, "K" is 3, 4, 5, 6, 7, 8, 9, ...), the arithmetic unit 63 may determine the "K+1" position of the "K+1" holder that holds the first workpiece 91 based on the first shape S1 of the first workpiece 91 (more specifically, the first shape data SH1 that represents the first shape S1) and the lengths from each of the already positioned "K" holders. 【0185】 The arithmetic unit 63 may generate a "K" map which is a combination of the length distributions from each of the "K" holders whose positions have already been determined. Based on the "K" map, the arithmetic unit 63 may determine the "K+1" position of the "K+1" holder. 【0186】 The arithmetic unit 63 may display the "K" map on the display 67. The display 67 may display multiple face elements EL in different colors according to the length to the nearest holder among the "K" holders whose positions have already been determined. 【0187】 If, after determining the positions of K of the holders 31, the arithmetic unit 63 cannot determine the position of the K+1 holder such that the length from each of the K holders' positions is greater than or equal to a preset first threshold, it may determine the number of holders 31 used to hold the first workpiece 91 to be K. 【0188】 When "K" is defined as any natural number greater than or equal to 3 (for example, "K" is 3, 4, 5, 6, 7, 8, 9, ...), the arithmetic unit 63 determines the positions of the "K" holders and then determines the position of the "K+1" holder that holds the first workpiece 91. The arithmetic unit 63 may determine the position of the "K+1" holder such that the minimum length from each of the already determined "K" holders to the "K+1" holder is substantially maximized. 【0189】 (Condition: The entire workpiece holding surface is in contact with the first workpiece 91) As illustrated in Figure 16, the arithmetic unit 63 may determine the first position P1 of the first holder 31a that holds the first workpiece 91 such that the condition is met that the entire workpiece holding surface of the first holder 31a is in contact with the first workpiece 91. As illustrated in Figure 16, the arithmetic unit 63 may determine the second position P2 of the second holder 31b that holds the first workpiece 91 such that the condition is met that the entire workpiece holding surface of the second holder 31b is in contact with the first workpiece 91. When "K" is defined as any natural number greater than or equal to 3 (for example, "K" is 3, 4, 5, 6, 7, 8, 9, ...), the arithmetic unit 63 may determine the "K" position of the "K" holder that holds the first workpiece 91 such that the condition is met that the entire workpiece holding surface of the "K" holder is in contact with the first workpiece 91. 【0190】 For example, the arithmetic unit 63 may determine the first position P1 of the first holder 31a that holds the first workpiece 91, based on the allowable area BR (see Figure 29), such that the condition is met that the entire workpiece holding surface of the first holder 31a is in contact with the first workpiece 91. The arithmetic unit 63 may also determine the second position P2 of the second holder 31b that holds the first workpiece 91, based on the allowable area BR (see Figure 29), such that the condition is met that the entire workpiece holding surface of the second holder 31b is in contact with the first workpiece 91. When "K" is defined as any natural number greater than or equal to 3 (where "K" is, for example, 3, 4, 5, 6, 7, 8, 9, ...), the arithmetic unit 63 may determine the "K" position of the "K" holder that holds the first workpiece 91, based on the allowable area BR (see Figure 29), such that the condition is met that the entire workpiece holding surface of the "K" holder is in contact with the first workpiece 91. 【0191】 (Computer 60) As illustrated in Figure 35, the workpiece transfer device 10A includes at least one computer 60. As illustrated in Figure 36, the computer 60 includes a memory 62, an arithmetic unit 63, and a communication circuit 64. The computer 60 may also include an input device 66 and / or a display 67. In the example shown in Figure 36, the memory 62, the arithmetic unit 63, the communication circuit 64, the input device 66, and the display 67 are connected via a bus 68. The computer 60 may constitute at least part of a control device 6 that controls the moving device 4 of the workpiece transfer device 10A. More specifically, the computer 60 may be a higher-level computer that sends commands or control data to a first control device 70 (see Figure 35) that transmits control commands to the moving device 4 of the workpiece transfer device 10A. 【0192】 As illustrated in Figure 36, the arithmetic unit 63 includes at least one processor 63a (e.g., at least one CPU). 【0193】 The arithmetic unit 63 executes the first process U1 described above by executing the program PG stored in memory 62. The arithmetic unit 63 executes the second process U2 and the third process U3 described above by executing the program PG stored in memory 62. The arithmetic unit 63 may execute the fourth process U4 and / or the fifth process U5 described above by executing the program PG stored in memory 62. 【0194】 Memory 62 is a storage medium (more specifically, a non-temporary computer-readable storage medium) that can be read by the arithmetic unit 63. Memory 62 may be, for example, a non-volatile or volatile semiconductor memory such as RAM, ROM, or flash memory, or it may be a magnetic disk or other form of memory. 【0195】 Memory 62 stores the program PG and various data. Memory 62 may be distributed across multiple locations. For example, memory for storing data may be provided separately from the memory for storing the program. Memory 62 may include cloud storage accessible via a network. 【0196】 As illustrated in Figure 36, the memory 62 may store shape data SH of the shape S (see Figure 31) that includes the first workpiece 91. The memory 62 may store first shape data SH1 indicating the first shape S1 of the first workpiece 91, and / or second shape data SH2 indicating the second shape S2 of the second workpiece 92. As illustrated in Figure 36, the memory 62 may store first centroid data GD1 indicating the centroid position G1 of the first workpiece 91, and / or second centroid data GD2 indicating the centroid position G2 of the second workpiece 92. As illustrated in Figure 36, the memory 62 may store a plurality of coordinates PC, including the first coordinate PC1, the second coordinate PC2, and the third coordinate PC3 described above. The plurality of coordinates PC may include the fourth coordinate PC4 and / or the fifth coordinate PC5 described above. The memory 62 may store a margin distance MG for deriving the allowable area BR described above. 【0197】 As illustrated in Figure 36, the input device 66 may include a keyboard 66k. Alternatively, or additionally, the input device 66 may include a pointing device such as a mouse, or a touch panel on a display 67. 【0198】 (Holding body 31) In the example shown in Figure 35, the first holder 31a holds the first part 91-1 of the first workpiece 91. The second holder 31b holds the second part 91-2 of the first workpiece 91. The third holder 31c holds the third part 91-3 of the first workpiece 91. The fourth holder 31d holds the fourth part 91-4 of the first workpiece 91. 【0199】 The first holder 31a may be a first electromagnet 311a (see Figure 37) or a first vacuum suction pad. The second holder 31b may be a second electromagnet 311b (see Figure 37) or a second vacuum suction pad. The third holder 31c may be a third electromagnet 311c (see Figure 37) or a third vacuum suction pad. The fourth holder 31d may be a fourth electromagnet 311d (see Figure 37) or a fourth vacuum suction pad. 【0200】 In the example shown in Figure 37, the plurality of holders 31 include a fifth holder 31e. The fifth holder 31e may be a fifth electromagnet 311e or a fifth vacuum suction pad. The plurality of holders 31 may also include a sixth holder 31f (e.g., a sixth electromagnet 311f) and / or a seventh holder 31g (e.g., a seventh electromagnet 311g). The plurality of holders 31 may also include an eighth holder 31h (e.g., an eighth electromagnet 311h) and / or a ninth holder 31i (e.g., a ninth electromagnet 311i). 【0201】 (Support 33) As illustrated in Figure 37, the workpiece transfer device 10A includes a support 33 that supports a plurality of holders 31. The support 33 may have a plate 331 that supports the plurality of holders 31. The workpiece transfer device 10A may also include a plate support device 35 that supports the plate 331. 【0202】 The support 33 (more specifically, the plate 331) supports the first retainer 31a, the second retainer 31b, and the third retainer 31c. In the example shown in Figure 37, the support 33 (more specifically, the plate 331) supports the fourth retainer 31d, the fifth retainer 31e, the sixth retainer 31f, the seventh retainer 31g, the eighth retainer 31h, and the ninth retainer 31i. The number of retainers 31 supported by the support 33 (more specifically, the plate 331) may be six or fewer, or seven or more. The number of retainers 31 supported by the support 33 (more specifically, the plate 331) may be ten or fewer, or eleven or more. 【0203】 (Attachment 3) In the example shown in Figure 38, the workpiece transfer device 10A comprises a plurality of attachments 3 and a support 33 (more specifically, a plate 331) that supports the plurality of attachments 3. 【0204】 In the example shown in Figure 38, the multiple attachments 3 include a first attachment 3b having a second retainer 31b, and a second attachment 3c having a third retainer 31c. The multiple attachments 3 may also include a third attachment 3d having a fourth retainer 31d, and / or a fourth attachment 3e having a fifth retainer 31e. The multiple attachments 3 may also include a fifth attachment 3f having a sixth retainer 31f, and / or a sixth attachment 3g having a seventh retainer 31g. The multiple attachments 3 may also include a seventh attachment 3h having an eighth retainer 31h, and / or an eighth attachment 3i having a ninth retainer 31i. 【0205】 Multiple attachments 3 are attached to the support 33 (more specifically, the plate 331). In the example shown in Figure 38, each of the multiple attachments 3 can be independently removed from the support 33 (more specifically, the plate 331). 【0206】 As illustrated in Figure 39, multiple attachments 3 can be attached to the support 33 (more specifically, the plate 331) in the first layout LA1. In the example shown in Figure 39, the multiple attachments 3 attached to the support 33 (more specifically, the plate 331) in the first layout LA1 can hold a workpiece (hereinafter referred to as the "third workpiece 93"). 【0207】 As illustrated in Figure 40, multiple attachments 3 can be reattached to the support 33 (more specifically, the plate 331) in a second layout LA2 that is different from the first layout LA1. In the example shown in Figure 40, the multiple attachments 3 attached to the support 33 (more specifically, the plate 331) in the second layout LA2 can hold the first workpiece 91 which has a different shape from the third workpiece 93. 【0208】 In the examples shown in Figures 39 and 40, the layout of multiple attachments 3 can be changed to correspond to the difference between the shape of the third workpiece 93 and the shape of the first workpiece 91. 【0209】 In the example shown in Figure 39, there are eight attachments 3 that can be attached to the support 33 (more specifically, the plate 331). Alternatively, the number of attachments 3 may be three, four, five, six, seven, nine, or ten. Even more alternatively, the number of attachments 3 may be eleven or more. 【0210】 In the examples shown in Figures 39 and 40, the position of the second retainer 31b relative to the support 33 is changed by performing an operation that includes removing the first attachment 3b, which has the second retainer 31b, from the support 33 and then reattaching the first attachment 3b to the support 33. Alternatively, the position of the second retainer 31b relative to the support 33 may be changed without removing the second retainer 31b from the support 33. For example, the second retainer 31b may be supported by the support 33 so that it is slidable relative to the support 33. Similarly, the position of other retainers relative to the support 33 may be changed without removing those other retainers from the support 33. 【0211】 (First holding body 31a) In the example shown in Figure 38, the first retainer 31a is fixed to the plate 331 by bolts BT. The first retainer 31a is permanently fixed to the support 33 (more specifically, the plate 331). Alternatively, the first retainer 31a may be included in one of the multiple attachments 3. 【0212】 In the example shown in Figure 38, the first holder 31a is the first electromagnet 311a. In the example shown in Figure 38, the workpiece transfer device 10A includes a first cable 511a that supplies power to the first electromagnet 311a. When the first holder 31a holds the first workpiece 91, current is supplied to the first electromagnet 311a via the first cable 511a. When the first workpiece 91 is removed from the first holder 31a, the supply of current to the first electromagnet 311a is stopped. 【0213】 In the example shown in Figure 37, the first retainer 31a is fixed to the center of the plate 331. In the example shown in Figure 37, the first retainer 31a is positioned on the central axis C1 of the plate support device 35 that supports the plate 331. 【0214】 (Second holding body 31b) In the example shown in Figure 37, the second holder 31b is the second electromagnet 311b. In the example shown in Figure 37, the workpiece transfer device 10A includes a second cable 511b that supplies power to the second electromagnet 311b. When the second holder 31b holds the first workpiece 91, current is supplied to the second electromagnet 311b via the second cable 511b. When the first workpiece 91 is removed from the second holder 31b, the supply of current to the second electromagnet 311b is stopped. 【0215】 The first attachment 3b, having a second holder 31b, may be attachable to the plate 331 by magnetic force. More specifically, the first attachment 3b may have a first mounting electromagnet 312b that is magnetically coupled to the plate 331, in addition to the second electromagnet 311b. When the first attachment 3b is attached to the plate 331, current is supplied to the first mounting electromagnet 312b via the cable 512b. When the first attachment 3b is removed from the plate 331, the supply of current to the first mounting electromagnet 312b is stopped. 【0216】 As illustrated in Figure 41, the first attachment 3b may have a first insulator 314b positioned between the second electromagnet 311b and the first mounting electromagnet 312b. The first insulator 314b electrically insulates the second electromagnet 311b and the first mounting electromagnet 312b. 【0217】 The second electromagnet 311b may be tiltable relative to the first mounting electromagnet 312b. As illustrated in Figure 41, the first attachment 3b may include a first spring 315b. Furthermore, when the second electromagnet 311b tilts relative to the first mounting electromagnet 312b, the first spring 315b may deform. The first attachment 3b may include a plurality of springs, including the first spring 315b. Furthermore, when the second electromagnet 311b tilts relative to the first mounting electromagnet 312b, the plurality of springs, including the first spring 315b, may deform. 【0218】 If the second electromagnet 311b is tiltable relative to the first mounting electromagnet 312b, poor holding of the first workpiece 91 due to deflection of the first workpiece 91, manufacturing errors of the first attachment 3b, deflection of the plate 331, etc., is less likely to occur. 【0219】 (Third holding body 31c) In the example shown in Figure 37, the third holder 31c is the third electromagnet 311c. In the example shown in Figure 37, the workpiece transfer device 10A includes a third cable 511c that supplies power to the third electromagnet 311c. When the third holder 31c holds the first workpiece 91, current is supplied to the third electromagnet 311c via the third cable 511c. When the first workpiece 91 is removed from the third holder 31c, the supply of current to the third electromagnet 311c is stopped. 【0220】 As illustrated in Figure 41, the second attachment 3c having the third holder 31c may be attachable to the plate 331 by magnetic force. More specifically, the second attachment 3c may have a second mounting electromagnet 312c that is magnetically coupled to the plate 331, in addition to the third electromagnet 311c. When the second attachment 3c is attached to the plate 331, current is supplied to the second mounting electromagnet 312c via the cable 512c. When the second attachment 3c is removed from the plate 331, the supply of current to the second mounting electromagnet 312c is stopped. 【0221】 As illustrated in Figure 41, the second attachment 3c may have a second insulator 314c positioned between the third electromagnet 311c and the second mounting electromagnet 312c. The second insulator 314c electrically insulates the third electromagnet 311c and the second mounting electromagnet 312c. 【0222】 The third electromagnet 311c may be tiltable relative to the second mounting electromagnet 312c. As illustrated in Figure 41, the second attachment 3c may include a second spring 315c. Furthermore, when the third electromagnet 311c tilts relative to the second mounting electromagnet 312c, the second spring 315c may deform. 【0223】 When the third electromagnet 311c is tiltable with respect to the second attachment electromagnet 312c, it is difficult for the holding failure of the first workpiece 91 to occur due to the deflection of the first workpiece 91, the manufacturing error of the second attachment 3c, the deflection of the plate 331, and the like. 【0224】 (The "K"th holding body) When "K" is defined as an arbitrary natural number of 3 or more ("K" is, for example, 3, 4, 5, 6, 7, 8, 9, ···), the "K"th holding body 31 may be the "K"th electromagnet. The ("K - 1")th attachment having the "K"th holding body may be attachable to the plate 331 by magnetic force. 【0225】 (Movable holding body 32) As illustrated in FIG. 38, the workpiece transfer device 10A includes a movable holding body 32 capable of holding another workpiece (for example, a small workpiece 94 smaller than the first workpiece 91 as shown in FIG. 42), and a movable holding body moving device 531 (for example, an air cylinder 531s) that moves the movable holding body 32 in a direction substantially perpendicular to the main surface 331m of the plate 331 (more specifically, the attachment mounting surface of the plate 331). 【0226】 In the example described in FIG. 38, the movable holding body 32 is an electromagnet 32a (in other words, a movable electromagnet) that attracts another workpiece (for example, the small workpiece 94). In the example described in FIG. 38, the workpiece transfer device 10A includes a cable 532 that supplies power to the electromagnet 32a (in other words, the movable electromagnet). The movable holding body 32 may be omitted. 【0227】 (Attachment support device 15) In the example described in FIG. 42, the workpiece transfer device 10A includes an attachment support device 15 that supports the attachment 3 removed from the plate 331 among the plurality of attachments 3. 【0228】 The attachment support device 15 includes a first support device 15b capable of supporting the first attachment 3b and a second support device 15c capable of supporting the second attachment 3c. The second support device 15c is provided separately from the first support device 15b. The attachment support device 15 may include a third support device 15d capable of supporting the third attachment 3d and / or a fourth support device 15e capable of supporting the fourth attachment 3e. The attachment support device 15 may include a number of support devices equal to or greater than the number of attachments 3. For example, when defining "K" as any natural number of 3 or more (where "K" is, for example, 3, 4, 5, 6, 7, 8, 9, ···), the work transfer device 10A includes "K" attachments, and the attachment support device 15 may include "K" or more support devices. 【0229】 (Moving device 4) As illustrated in FIG. 43, the moving device 4 may include an articulated robot 41. In the example shown in FIG. 43, a support 33 that supports a plurality of holders 31 is attached to the tip arm AM1 of the articulated robot 41. A plate support device 35 that supports a plate 331 may be attached to the tip arm AM1 of the articulated robot 41. 【0230】 In the example shown in FIG. 43, the articulated robot 41 includes a plurality of arms AM, a plurality of joints JT, and a plurality of arm drive devices (for example, a plurality of motors MT that move the plurality of joints JT) that move the plurality of joints JT. The articulated robot 41 has, for example, at least six rotational axes. 【0231】 As illustrated in FIG. 42, the moving device 4 may include a robot moving device 42 that moves the entire articulated robot 41. The robot moving device 42 moves the articulated robot 41 in a direction parallel to the horizontal plane. In the example shown in FIG. 42, the robot moving device 42 moves the articulated robot 41 in a direction along the X-axis parallel to the horizontal plane. 【0232】 Alternatively, the moving device 4 may include a first linear motion device for moving the support 33 in a direction parallel to the vertical direction, and a second linear motion device for moving the support 33 in a direction parallel to the horizontal plane. The second linear motion device may include a device for moving the support 33 in a direction along the X-axis parallel to the horizontal plane, and a device for moving the support 33 in a direction along the Y-axis parallel to the horizontal plane. 【0233】 (Platform 12) In the example shown in Figure 42, the workpiece transfer device 10A includes a first platform 12 capable of supporting a plurality of workpieces 9, including a first workpiece 91. The first platform 12 may include a first pallet PT1 on which a plurality of workpieces 9, including the first workpiece 91, can be placed, and a first support base 121 that supports the plurality of workpieces via the first pallet PT1. 【0234】 The first support base 121 may include a pallet moving device 121b for moving a pallet (e.g., the first pallet PT1). In the example shown in Figure 42, the pallet moving device 121b moves the first pallet PT1 in a direction parallel to the horizontal plane. In the example shown in Figure 42, the pallet moving device 121b moves the first pallet PT1 in a direction along the X-axis parallel to the horizontal plane. 【0235】 In the example shown in Figure 42, the mobile device 4 (more specifically, the articulated robot 41 and the robot mobile device 42) can move the support 33 (more specifically, the plate 331) between a position facing the first platform 12 and a position facing the attachment support device 15. 【0236】 In the example shown in Figure 42, the mobile device 4 (more specifically, the articulated robot 41 and the robot mobile device 42) can move the support 33 (more specifically, the plate 331) between a position facing the first platform 12 and a position facing the second platform 13a. 【0237】 (Second platform 13a, and third platform 13b) As illustrated in Figure 42, the workpiece transfer device 10A may include a second platform 13a for receiving workpieces 9 (e.g., a first workpiece 91) that are transferred by a plurality of holders 31. The second platform 13a may include a second pallet PT2 on which the workpieces 9 (e.g., a first workpiece 91) can be placed, and a second support base 131a for supporting the workpieces (e.g., a first workpiece 91) via the second pallet PT2. 【0238】 In the example shown in Figure 42, the workpiece transport device 10A can transport the workpiece 9 (for example, the first workpiece 91) from the first platform 12 to the second platform 13a. 【0239】 The workpiece transfer device 10A may include a third platform 13b for receiving workpieces 9 that are transferred by a plurality of holders 31. The third platform 13b may include a third pallet PT3 on which workpieces can be placed, and a third support base 131b for supporting the workpieces 9 via the third pallet PT3. 【0240】 In the example shown in Figure 42, the workpiece transfer device 10A is capable of transferring workpieces from the first platform 12 to the third platform 13b. In the example shown in Figure 42, the third platform 13b may be omitted. 【0241】 (Power supply device 16) If the workpiece transfer device 10A is equipped with multiple electromagnets (for example, a first electromagnet 311a, a second electromagnet 311b, a first mounting electromagnet 312b, etc.), the workpiece transfer device 10A is equipped with a power supply device 16 that supplies current to the multiple electromagnets, as illustrated in Figure 44. Alternatively, if the workpiece transfer device 10A is equipped with multiple vacuum suction pads, the workpiece transfer device 10A is equipped with a vacuum pump that sucks air from the multiple vacuum suction pads. 【0242】 (Control device 6) In the example shown in Figure 44, the workpiece transfer device 10A includes a control device 6 that controls the moving device 4 (for example, an articulated robot 41). The control device 6 also controls the state of the multiple holders 31 (or the state of the multiple attachments 3). More specifically, the control device 6 switches the state of each of the multiple holders 31 between a state in which a workpiece such as the first workpiece 91 is held and a state in which the holding of the workpiece such as the first workpiece 91 is released. 【0243】 The control device 6 may control the power supply device 16 so that current is supplied to the first electromagnet 311a. When current is supplied to the first electromagnet 311a, the first electromagnet 311a holds the workpiece 9 (for example, the first workpiece 91) by magnetic force. The control device 6 may control the power supply device 16 so that current is supplied to the second electromagnet 311b. When current is supplied to the second electromagnet 311b, the second electromagnet 311b holds the workpiece 9 (for example, the first workpiece 91) by magnetic force. The control device 6 may control the power supply device 16 so that current is supplied to the first mounting electromagnet 312b. When current is supplied to the first mounting electromagnet 312b, the first attachment 3b is attached to the plate 331 by magnetic force. 【0244】 Additionally, the control device 6 may control the attachment support device 15. For example, if the attachment support device 15 (more specifically, the first support device 15b) has a gripping device 151b, the control device 6 may control the gripping device 151b of the first support device 15b. 【0245】 One computer may function as the control device 6, or multiple computers may cooperate to function as the control device 6. For example, the control device 6 may include a first control device 70 that controls multiple holders 31 and a moving device 4 (e.g., an articulated robot 41), and a higher-level computer 60 that sends commands or control data to the first control device 70. 【0246】 In the example described in FIG. 44, the first control device 70 includes a hardware processor (hereinafter referred to as "second processor 71"), a memory (hereinafter referred to as "second memory 72"), a communication circuit (hereinafter referred to as "second communication circuit 74"), an input device (hereinafter referred to as "second input device 76"), and a display (hereinafter referred to as "second display 77"). The second processor 71, the second memory 72, the second communication circuit 74, the second input device 76, and the second display 77 are connected to each other via a bus 78. In the example described in FIG. 44, the second input device 76 includes a touch panel 76t on the second display 77. In other words, the second display 77 is a display with a touch panel 76t. The second input device 76 may include buttons, switches, levers, pointing devices, and / or a keyboard. 【0247】 The second memory 72 is a storage medium readable by the second processor 71 of the first control device 70 (more specifically, a non-temporary computer-readable storage medium). The second memory 72 may be, for example, a non-volatile or volatile semiconductor memory such as RAM, ROM, flash memory, etc., a magnetic disk, or other forms of memory. 【0248】 The second memory 72 stores data and a control program PM1. When the second processor 71 of the first control device 70 executes the control program PM1 stored in the second memory 72, the first control device 70 generates a control command. Further, the second communication circuit 74 transmits the control command to a controlled device (more specifically, the mobile device 4, the power supply device 16, the attachment support device 15, etc.). Thus, when the second processor 71 executes the control program PM1, the first control device 70 can control the controlled device (more specifically, the mobile device 4, the power supply device 16, the attachment support device 15, etc.). 【0249】 (First position change mode M1-1) As illustrated in Figure 45, the control device 6 can perform a first position change mode M1-1 that changes the position of the second retainer 31b relative to the support 33 (more specifically, the plate 331). 【0250】 As illustrated in Figure 45, the control device 6 may perform the first position change mode M1-1 by controlling the moving device 4 (e.g., articulated robot 41) and the attachment support device 15. Alternatively, if the second holder 31b is supported on the support 33 so as to be slidable relative to the support 33, the first position change mode M1-1 may include sliding the second holder 31b relative to the support 33. 【0251】 In the example shown in Figure 45, the first position change mode M1-1 includes changing the mounting position of the first attachment 3b to the support 33 (more specifically, the plate 331) from the first mounting position T1 to the second mounting position T2. 【0252】 The first position change mode M1-1 may include the control device 6 transmitting a first movement command to the moving device 4 (e.g., articulated robot 41) so that the first attachment 3b moves to a position facing the attachment support device 15 (more specifically, the first support device 15b). 【0253】 The first position change mode M1-1 may include transmitting a gripping command to the gripping device 151b so that the gripping device 151b grips the first attachment 3b. The first position change mode M1-1 may also include transmitting a first demagnetization command from the control device 6 to the power supply device 16 so that the first mounting electromagnet 312b is demagnetized after the first attachment 3b has been gripped by the gripping device 151b. 【0254】 The first position change mode M1-1 may include sending a second movement command from the control device 6 to the moving device 4 (e.g., articulated robot 41) so that the second mounting position T2 on the plate 331 moves to a position opposite the first attachment 3b. 【0255】 The first position change mode M1-1 may include the control device 6 sending a first excitation command to the power supply device 16 so that the first mounting electromagnet 312b is energized after the second mounting position T2 on the plate 331 moves to a position facing the first attachment 3b. The first position change mode M1-1 may also include the control device 6 sending a grip release command to the gripping device 151b so that the gripping device 151b releases its grip on the first attachment 3b after the second mounting position T2 on the plate 331 moves to a position facing the first attachment 3b. 【0256】 (Nth position change mode) When "N" is defined as any natural number greater than or equal to 2 (where "N" is, for example, 2, 3, 4, 5, 6, 7, 8, ...), the control device 6 can perform an "N" position change mode that changes the position of the "N+1" retainer relative to the support 33 (more specifically, the plate 331). The "N" position change mode may also be a mode that changes the mounting position of the "N" attachment relative to the support 33 (more specifically, the plate 331). For example, the second position change mode is a mode that changes the position of the third retainer 31c relative to the support 33 (more specifically, the mounting position of the second attachment 3c relative to the plate 331). 【0257】 (Layout change mode M1) As illustrated in Figures 39 and 40, the control device 6 can execute a layout change mode M1 that changes the layout of the multiple holders 31 from a first layout LA1 to a second layout LA2. The layout change mode M1 may also be a mode that changes the layout of the multiple attachments 3 from a first layout LA1 to a second layout LA2. 【0258】 The layout change mode M1 includes the first position change mode M1-1 described above, and the second position change mode described above. When "K" is defined as any natural number greater than or equal to 3 (for example, "K" is 3, 4, 5, 6, 7, 8, ...), the layout change mode M1 may also include the above-described "K" position change mode. 【0259】 The layout change mode M1 may include changing the layout of the multiple holders 31 on the plate 331 from a first layout LA1 (see Figure 39) that conforms to the shape of the third workpiece 93 to a second layout LA2 (see Figure 40) that conforms to the first shape S1 of the first workpiece 91, based on third shape data indicating the shape of the third workpiece 93 and first shape data SH1 indicating the first shape S1 of the first workpiece 91. 【0260】 (First transport mode M2-1) As illustrated in Figure 47, the control device 6 is capable of executing a first transport mode M2-1 for transporting the first workpiece 91. 【0261】 In the example shown in Figure 47, the first transport mode M2-1 is a mode in which a first workpiece 91, held by a plurality of holders 31 including a first holder 31a positioned at a first position, a second holder 31b positioned at a second position, and a third holder 31c positioned at a third position, is transported using a moving device 4 (for example, an articulated robot 41). Also in the example shown in Figure 47, the first transport mode M2-1 is a mode in which a first workpiece 91, held by a plurality of holders 31 arranged in the second layout LA2, is transported using a moving device 4 (for example, an articulated robot 41). 【0262】 Memory 62 may store first pickup position data DE1 indicating the pickup position Q1 of the first workpiece 91 and first release position data DE2 indicating the release position Q2 of the first workpiece 91. In the example shown in Figure 47, the pickup position Q1 is located on the first platform 12 and the release position Q2 is located on the second platform 13a. The first transport mode M2-1 may include transporting the first workpiece 91 from the pickup position Q1 to the release position Q2 based on the first pickup position data DE1 and the first release position data DE2. 【0263】 (Second transport mode M2-2) As illustrated in Figure 48, the control device 6 can execute a second transport mode M2-2 for transporting the second workpiece 92. As illustrated in Figure 49, the second transport mode M2-2 may be executed simultaneously with the first transport mode M2-1. More specifically, the control device 6 may execute a simultaneous transport mode in which the first workpiece 91 and the second workpiece 92 are transported simultaneously using a plurality of holders 31. 【0264】 Alternatively, the second transport mode M2-2 may be performed after the first transport mode M2-1 has been performed. More specifically, the control device 6 may perform the following: (1) transport the first workpiece 91 using a plurality of holders 31 arranged in the second layout LA2 and a moving device 4 (e.g., an articulated robot 41), as illustrated in Figure 47; (2) change the layout of the plurality of holders 31 from the second layout LA2 to the third layout LA3; and (3) transport the second workpiece 92 using a plurality of holders 31 arranged in the third layout LA3 and a moving device 4 (e.g., an articulated robot 41), as illustrated in Figure 48. 【0265】 (Third transport mode M2-3) As illustrated in Figure 46, the control device 6 is capable of executing a third transport mode M2-3 for transporting the third workpiece 93. In the example shown in Figure 46, the third transport mode M2-3 is a mode in which the third workpiece 93, held by a plurality of holders 31 arranged in the first layout LA1, is transported using a moving device 4 (e.g., an articulated robot 41). 【0266】 In the examples shown in Figures 46 and 47, the third transport mode M2-3 is executed before the first transport mode M2-1 is executed. In the examples shown in Figures 46 and 47, the control device 6 executes: (1) transporting the third workpiece 93 using a plurality of holders 31 arranged in the first layout LA1 and a moving device 4 (e.g., an articulated robot 41); (2) changing the layout of the plurality of holders 31 from the first layout LA1 to the second layout LA2; and (3) transporting the first workpiece 91 using a plurality of holders 31 arranged in the second layout LA2 and a moving device 4 (e.g., an articulated robot 41). The control device 6 may also execute transporting the third workpiece 93, changing the layout of the plurality of holders 31 from the first layout LA1 to the second layout LA2, and transporting the first workpiece 91 sequentially in this order. 【0267】 (Sorting Mode M3) The control device 6 may be capable of executing a sorting mode M3 in which multiple workpieces 9 are sorted into multiple groups using multiple holders 31 and a moving device 4 (for example, an articulated robot 41). 【0268】 Figures 46 to 48 schematically show how multiple workpieces 9 are sorted into multiple groups. In sorting mode M3, multiple workpieces 9 may be sorted into multiple groups based on the type of subsequent process. For example, in sorting mode M3, multiple workpieces 9 may be sorted into groups that require welding and groups that do not require welding. Alternatively, or additionally, in sorting mode M3, multiple workpieces may be sorted into groups that require bending and groups that do not require bending. 【0269】 Alternatively, or additionally, in sorting mode M3, multiple workpieces 9 may be sorted into groups of smaller size and groups of larger size. 【0270】 In the example shown in Figure 47, the first workpiece 91 is classified into the first group. The first workpiece 91, classified into the first group, is transported from the first platform 12 to one side 1311a of the second platform 13a. In the example shown in Figure 48, the second workpiece 92 is classified into the second group. The second workpiece 92, classified into the second group, is transported from the first platform 12 to the other side 1312a of the second platform 13a. 【0271】 In the examples shown in Figures 47 and 48, the first workpiece 91 and the second workpiece 92 are classified into the third group. The first workpiece 91 and the second workpiece 92, classified into the third group, are transported from the first platform 12 to the second platform 13a. In the example shown in Figure 46, the third workpiece 93 is classified into the fourth group. The third workpiece 93, classified into the fourth group, is transported from the first platform 12 to the third platform 13b. Alternatively, the first workpiece 91 and the second workpiece 92, classified into the first group, may be transported to the first corner of the second platform 13a, and the third workpiece 93, classified into the second group, may be transported to the second corner of the second platform 13a. 【0272】 (Third embodiment) The laser processing system 100 in the third embodiment will be described with reference to Figures 1 to 52. Figure 50 is a schematic diagram showing the laser processing system 100 in the third embodiment. Figure 51 is a schematic perspective view showing a part of the laser processing system 100 in the third embodiment. Figure 52 is a schematic diagram showing the process of acquiring shape data SH of shape S, which includes the first workpiece 91. 【0273】 The third embodiment will primarily describe the differences from the first and second embodiments. On the other hand, the third embodiment will omit repetitive explanations of matters already described in the first or second embodiment. Therefore, it goes without saying that matters already described in the first or second embodiment can be applied to the third embodiment even if they are not explicitly explained. Conversely, matters described in the third embodiment can also be adopted in the first and second embodiments. 【0274】 As illustrated in Figure 50, the laser processing system 100 in the third embodiment comprises a laser processing device 101, a workpiece transport device 10, a memory 62, and a calculation device 63. 【0275】 As illustrated in Figure 51, the laser processing apparatus 101 irradiates the raw material workpiece RW with a laser LB to form a plurality of workpieces 9, including the first workpiece 91, from the raw material workpiece RW. 【0276】 As illustrated in Figures 46 to 48, the workpiece transport device 10 transports multiple workpieces 9 using a plurality of holders 31, including a first holder 31a, a second holder 31b, and a third holder 31c. 【0277】 Memory 62 stores the first shape S1 of the first workpiece 91 (more specifically, the first shape data SH1 that represents the first shape S1 of the first workpiece 91). 【0278】 As illustrated in Figures 16 and 17, the arithmetic unit 63 determines the first position P1 of the first holder 31a that holds the first workpiece 91 based on the first shape S1 of the first workpiece 91 (more specifically, the first shape data SH1 representing the first shape S1). The arithmetic unit 63 determines the second position P2 of the second holder 31b that holds the first workpiece 91 based on the first shape S1 of the first workpiece 91 (more specifically, the first shape data SH1 representing the first shape S1) and the first length L1 from the first holder 31a. The arithmetic unit 63 determines the third position P3 of the third holder 31c that holds the first workpiece 91 based on the first shape S1 of the first workpiece 91 (more specifically, the first shape data SH1 representing the first shape S1), the first length L1 from the first holder 31a, and the second length L2 from the second holder 31b. 【0279】 The workpiece transfer device 10 may be the workpiece transfer device 10A in the second embodiment, or it may be any other workpiece transfer device. Since the workpiece transfer device 10A in the second embodiment has already been described, a repetitive explanation of the workpiece transfer device 10A will be omitted. 【0280】 The arithmetic unit 63 is included in the computer 60. The computer 60 may be included in the control device 6 that controls the workpiece transport device 10. Alternatively, the computer 60 may be independent of the workpiece transport device 10. The memory 62 may be included in the computer 60. Alternatively, the memory 62 may be storage provided separately from the computer 60. For example, the memory 62 may include cloud storage accessible via a network. 【0281】 The laser processing system 100 in the third embodiment provides the same effects as the workpiece transport device 10A in the second embodiment. 【0282】 (Optional additional configuration) Next, with reference to Figures 1 to 52, optional additional configurations that can be adopted in the laser processing system 100 in the third embodiment will be described. 【0283】 (Laser processing device 101) In the example shown in Figure 51, the laser processing apparatus 101 comprises a laser irradiation device 102 having a laser head 102a, a head moving device 103 for moving the laser head 102a, and a workpiece support device 106. In the example shown in Figure 51, the workpiece support device 106 supports the workpiece (e.g., raw material workpiece RW) via a pallet (e.g., first pallet PT1). 【0284】 (Pallet moving device 121b) As illustrated in Figure 50, the laser processing system 100 may include a pallet moving device 121b that moves a pallet (e.g., a first pallet PT1) from a first region LR1 where the raw material workpiece RW is processed by a laser emitted from the laser head 102a to a second region LR2 accessible by the workpiece transport device 10. 【0285】 (Mobile device 4) As illustrated in Figure 42, the mobile device 4 may include an articulated robot 41. The mobile device 4 may also include a robot mobile device 42 for moving the articulated robot 41. 【0286】 (Attachment support device 15) As illustrated in Figure 42, the laser processing system 100 may include an attachment support device 15 that supports attachments removed from the plate 331 among the multiple attachments 3. Since the attachment support device 15 has already been described in the second embodiment, a description of the attachment support device 15 will be omitted. 【0287】 (Platform 12, Platform 23a, Platform 33b) The laser processing system 100 may include a first platform 12. The laser processing system 100 may also include a second platform 13a and / or a third platform 13b. The first platform 12, the second platform 13a, and the third platform 13b have been described in the second embodiment, so a description of these platforms will be omitted. 【0288】 (Power supply device 16) The laser processing system 100 may include a power supply device 16. Since the power supply device 16 has already been described in the second embodiment, a description of the power supply device 16 will be omitted. 【0289】 (Attachment 3) As illustrated in Figure 38, the workpiece transfer device 10 may include (1) a first attachment 3b having a second holder 31b, (2) a second attachment 3c having a third holder 31c, and (3) a plate 331 to which a plurality of attachments 3, including the first attachment 3b and the second attachment 3c, are attached. 【0290】 As illustrated in Figure 39, multiple attachments 3 can be mounted on the plate 331 in a first layout LA1. As illustrated in Figure 38, each of the multiple attachments 3 can be independently removed from the plate 331. Furthermore, as illustrated in Figure 40, multiple attachments 3 can be reattached to the plate 331 in a second layout LA2 that differs from the first layout LA1. In the examples shown in Figures 39 and 40, the layout of the multiple attachments 3 can be changed to correspond to the difference between the shape of the third workpiece 93 and the shape of the first workpiece 91. 【0291】 (Control device 6) In the example shown in Figure 50, the laser processing system 100 includes a control device 6. The control device 6 may include a first control device 70 that controls a plurality of holders 31 and a moving device 4 (e.g., an articulated robot 41), and a computer 60 that sends commands or control data to the first control device 70. The first control device 70 and the computer 60 have already been described in the first or second embodiment, so a repetitive description of the first control device 70 and the computer 60 will be omitted. 【0292】 The control device 6 may include a second control device 80 that controls the laser processing apparatus 101. In the example shown in Figure 50, the second control device 80 includes a hardware processor (hereinafter referred to as the "third processor 81"), a memory (hereinafter referred to as the "third memory 82"), a communication circuit (hereinafter referred to as the "third communication circuit 84"), an input device (hereinafter referred to as the "third input device 86"), and a display (hereinafter referred to as the "third display 87"). The third processor 81, the third memory 82, the third communication circuit 84, the third input device 86, and the third display 87 are connected to each other via a bus 88. In the example shown in Figure 50, the third input device 86 includes a touch panel 86t on the third display 87. In other words, the third display 87 is a display with a touch panel 86t. The third input device 86 may include buttons 86b, switches, levers, pointing devices, and / or a keyboard. 【0293】 The third memory 82 is a storage medium (more specifically, a non-temporary computer-readable storage medium) that can be read by the third processor 81 of the second control unit 80. The third memory 82 may be, for example, a non-volatile or volatile semiconductor memory such as RAM, ROM, or flash memory, or it may be a magnetic disk or other form of memory. 【0294】 The third memory 82 stores data and the machining program PM2. The third processor 81 of the second control device 80 executes the machining program PM2 stored in the third memory 82, causing the second control device 80 to generate control commands. The third communication circuit 84 then transmits these control commands to the controlled equipment (e.g., laser irradiation device 102, head movement device 103, etc.). In this way, by the third processor 81 executing the machining program PM2, the second control device 80 can control the controlled equipment (e.g., laser irradiation device 102, head movement device 103, etc.). 【0295】 (Shape data SH, and centroid data) As illustrated in Figure 52, the control device 6 (for example, a computer 60) may receive shape data SH of a shape S including the first workpiece 91 from a second computer 18 such as a CAD / CAM device 18a. The shape data SH may include first shape data SH1 showing the shape of the first workpiece 91, second shape data SH2 showing the shape of the second workpiece, and third shape data SH3 showing the shape of the third workpiece 93. The shape data SH may also be nesting data ND that specifies the positional relationship between the raw material workpiece RW and multiple workpieces including the first workpiece 91, the second workpiece 92, and the third workpiece 93. 【0296】 The control device 6 (for example, the computer 60) may receive first centroid data indicating the centroid position of the first workpiece 91, second centroid data indicating the centroid position of the second workpiece 92, and third centroid data indicating the centroid position of the third workpiece 93 from a second computer 18 such as a CAD / CAM device 18a. Alternatively or additionally, the control device 6 (for example, the computer 60) may derive the centroid position G1 of the first workpiece 91 based on first shape data SH1 indicating the shape of the first workpiece 91. Similarly, the control device 6 (for example, the computer 60) may derive the centroid position G2 of the second workpiece 92 based on second shape data SH2 indicating the shape of the second workpiece 92. Furthermore, the control device 6 (for example, the computer 60) may derive the centroid position G3 of the third workpiece 93 based on third shape data SH3 indicating the shape of the third workpiece 93. 【0297】 The first shape data SH1, which represents the shape of the first workpiece 91, and the first center of gravity data GD1, which represents the center of gravity position G1 of the first workpiece 91, are stored in the memory of the control device 6 (for example, the memory 62 of the computer 60). Similarly, the second shape data SH2, which represents the shape of the second workpiece 92, and the second center of gravity data GD2, which represents the center of gravity position G2 of the second workpiece 92, are stored in the memory of the control device 6 (for example, the memory 62 of the computer 60). In addition, the third shape data SH3, which represents the shape of the third workpiece 93, and the third center of gravity data G3, which represents the center of gravity position G3 of the third workpiece 93, are stored in the memory of the control device 6 (for example, the memory 62 of the computer 60). 【0298】 (Sorting data DE) Sorting data DE may be stored in memory (for example, memory 62 of computer 60). Sorting data DE may include first pickup position data DE1 indicating the pickup position Q1 of the first workpiece 91 (see Figure 47) and first release position data DE2 indicating the release position Q2 of the first workpiece 91 (see Figure 47). Sorting data DE may also include second pickup position data indicating the pickup position Q3 of the second workpiece 92 (see Figure 48) and second release position data indicating the release position Q4 of the second workpiece 92 (see Figure 48). Sorting data DE may also include third pickup position data indicating the pickup position Q5 of the third workpiece 93 (see Figure 46) and third release position data indicating the release position Q6 of the third workpiece 93 (see Figure 46). 【0299】 The sorting data DE may be created using the CAD / CAM device 18a, the computer 60, the first control device 70, or the second control device 80. 【0300】 (First process U1, second process U2, and third process U3) The control device 6 (more specifically, the computer 60) executes a program PG stored in memory 62 to perform a first process U1 that determines the first position P1 of the first holder 31a based on the first shape S1 of the first workpiece 91 (for example, based on first shape data SH1 representing the first shape S1 of the first workpiece 91 and first centroid data GD1 derived from the first shape data SH1). Since the first process U1 has already been described in the second embodiment, a repeated explanation of the first process U1 will be omitted. 【0301】 The control device 6 (more specifically, the computer 60) executes a program PG stored in memory 62 to perform a second process U2 that determines the second position P2 of the second holder 31b based on the first shape S1 of the first workpiece 91 (more specifically, the first shape data SH1 representing the first shape S1) and the first length L1 from the first holder 31a. The second process U2 has already been described in the second embodiment, so a repetitive explanation of the second process U2 will be omitted. 【0302】 The control device 6 (more specifically, the computer 60) executes a program PG stored in memory 62 to perform a third process U3 that determines the third position P3 of the third holder 31c based on the first shape S1 of the first workpiece 91 (more specifically, the first shape data SH1 representing the first shape S1), the first length L1 from the first holder 31a, and the second length L2 from the second holder 31b. Since the third process U3 has already been described in the second embodiment, a repeated explanation of the third process U3 will be omitted. 【0303】 The control device 6 (more specifically, the computer 60) may execute a program PG stored in memory 62 to perform a fourth process U4 to determine the fourth position P4 of the fourth holder 31d, and / or a fifth process U5 to determine the fifth position P5 of the fifth holder 31e. Since the fourth process U4 and the fifth process U5 have already been described in the second embodiment, a repetitive explanation of the fourth process U4 and the fifth process U5 will be omitted. 【0304】 (Processing program PM2) As illustrated in Figure 50, the memory of the control device 6 (more specifically, the third memory 82 of the second control device 80) stores the machining program PM2. The machining program PM2 may be created based on the nesting data ND described above and the machining conditions stored in the memory of the control device 6. The creation of the machining program PM2 is performed, for example, by the second control device 80. 【0305】 The second control device 80 generates multiple control commands by executing a processing program PM2 stored in memory (more specifically, the third memory 82 of the second control device 80), and transmits the generated multiple control commands to the laser processing device 101. Based on the multiple control commands received from the second control device 80, the laser processing device 101 forms multiple workpieces 9, including a first workpiece 91, a second workpiece 92, and a third workpiece 93, from the raw material workpiece RW. 【0306】 Multiple control commands may include a first control command, a second control command, and a third control command. The head moving device 103, which receives the first control command from the second control device 80, moves the laser head 102a relative to the raw material workpiece RW. The laser irradiation device 102, which receives the second control command from the second control device 80, irradiates the raw material workpiece RW with a laser. In this way, the raw material workpiece RW is laser processed. The pallet moving device 121b, which receives the third control command from the second control device 80, moves the first pallet PT1, which supports the first workpiece 91, the second workpiece 92, the third workpiece 93, and the scrap material LM formed from the raw material workpiece RW, from the first area LR1 where the raw material workpiece RW is processed to the second area LR2 accessible by the workpiece transport device 10. 【0307】 The second computer 18, such as the CAD / CAM device 18a, may transmit nesting data ND to the second control unit 80 and to the aforementioned computer 60 that executes the first process U1. For example, the nesting data ND may be transmitted to the computer 60 when the second control unit 80 executes a schedule that includes a machining program PM2 created based on the nesting data ND. 【0308】 Multiple processes, including the first process U1, the second process U2, and the third process U3 described above, may be executed during the machining process of the raw material workpiece RW. In this case, the first position P1, the second position P2, and the third position P3 can be determined using the time during which the raw material workpiece RW is machined. More specifically, the execution of the machining program PM2 by the second control device 80 and the execution of the program PG by the computer 60 described above may be performed simultaneously. 【0309】 Alternatively, the execution of the processing program PM2 and the multiple processes, including the first process U1, the second process U2, and the third process U3 described above, may be executed at completely separate times. 【0310】 (Transportation of Work 93, the third workpiece) The control device 6 (more specifically, the first control device 70) controls the workpiece transport device 10 (more specifically, the moving device 4) based on the third pickup position data and the third release position data, thereby transporting the third workpiece 93 from the third pickup position (for example, the pickup position Q5 on the first platform 12 shown in Figure 46) to the third release position (for example, the release position Q6 on the third platform 13b) using a plurality of holders 31 arranged in the first layout LA1. 【0311】 (Changing the layout of multiple holders) The control device 6 (more specifically, the first control device 70) changes the layout of the multiple holders 31 from the first layout LA1 to the second layout LA2 by controlling the workpiece transport device 10 (more specifically, the moving device 4, the attachment support device 15, and the power supply device 16) based on the first position P1 determined by the execution of the first process U1, the second position P2 determined by the execution of the second process U2, and the third position P3 determined by the execution of the third process U3. 【0312】 For example, the control device 6 may derive the relative position of the second position P2 to the first position P1 based on the first coordinate PC1 indicating the coordinate of the first position P1 and the second coordinate PC2 indicating the second position P2, and may also derive the relative position of the third position P3 to the first position P1 based on the first coordinate PC1 and the third coordinate PC3 indicating the third position P3. Furthermore, the control device 6 may change the layout of the multiple holders 31 from the first layout LA1 to the second layout LA2 by controlling the workpiece transfer device 10 based on the current position of the first holder 31a, the current position of the second holder 31b, the current position of the third holder 31c, the first position P1, the relative position of the second position P2 to the first position P1, and the relative position of the third position P3 to the first position P1. 【0313】 (Transportation of Workpiece 91) The control device 6 (more specifically, the first control device 70) controls the workpiece transport device 10 (more specifically, the moving device 4) based on the first pickup position data DE1 and the first release position data DE2, thereby transporting the first workpiece 91 from the first pickup position (for example, the pickup position Q1 on the first platform 12 shown in Figure 47) to the first release position (for example, the release position Q2 on the second platform 13a) using a plurality of holders 31 arranged in the second layout LA2. 【0314】 (Transportation of the second workpiece 92) The control device 6 (more specifically, the first control device 70) may perform a process to change the layout of the multiple holders 31 from the second layout LA2 to the third layout LA3. Alternatively, the control device 6 (more specifically, the first control device 70) may control the workpiece transport device 10 (more specifically, the moving device 4) based on the second pickup position data and the second release position data, thereby transporting the second workpiece 92 from the second pickup position (for example, the pickup position Q3 on the first platform 12 shown in Figure 48) to the second release position (for example, the release position Q4 on the second platform 13a) using the multiple holders 31 arranged in the third layout LA3. 【0315】 (Sorting process) The control device 6 (more specifically, the first control device 70) may perform a sorting process to divide the multiple workpieces 9 into multiple groups by controlling the multiple holders 31 and the moving device 4 based on first layout data showing a first layout LA1 of the multiple holders 31 that are suitable for the third workpiece 93, second layout data showing a second layout LA2 of the multiple holders 31 that are suitable for the first workpiece 91, third layout data showing a third layout LA3 of the multiple holders 31 that are suitable for the second workpiece 92, and the sorting data DE described above. 【0316】 (Fourth embodiment) The workpiece transport method in the fourth embodiment will be described with reference to Figures 1 to 54. Figure 53 is a diagram illustrating the creation of the nesting data file F3. Figure 54 is a flowchart showing an example of the workpiece transport method in the fourth embodiment. 【0317】 The fourth embodiment will primarily describe the differences from the first, second, and third embodiments. On the other hand, the fourth embodiment will omit repetitive explanations of matters already described in the first, second, or third embodiments. Therefore, it goes without saying that even if not explicitly explained in the fourth embodiment, matters already described in the first, second, or third embodiments can be applied to the fourth embodiment. 【0318】 The workpiece transport method in the fourth embodiment comprises a pre-processing step ST101, a step ST102 for determining the positions of the plurality of holders 31, and a transport step ST103. 【0319】 As illustrated in Figures 53 and 54, the preprocessing step may include creating a nesting data file F3 containing nesting data ND, which is a combination of the drawing data of the raw material work RW and the drawing data of the multiple parts PD, based on the drawing data file F1 of the raw material work RW and the drawing data files F2 of the multiple parts PD. The CAD / CAM device 18a may automatically create the nesting data file F3 based on the drawing data file F1 of the raw material work RW and the drawing data files F2 of the multiple parts. Alternatively, the nesting data file F3 may be created manually by an operator using the CAD / CAM device 18a. The nesting data file F3 is stored in the CAD / CAM device 18a. 【0320】 As illustrated in Figures 53 and 54, the preprocessing step may include creating joint data JD that indicates the location and size of the joint J connecting the multiple parts PDs, based on the boundary BL where the multiple parts PDs are in contact (more specifically, the length of the joint J in the direction along the slit line). The CAD / CAM device 18a may automatically create the joint data JD based on the nesting data ND. Alternatively, the joint data JD may be created manually by an operator using the CAD / CAM device 18a. As illustrated in Figure 52, the joint data JD (in other words, data indicating the location and size of the joint J connecting the multiple parts PDs) may be transmitted from the CAD / CAM device 18a to the computer 60. 【0321】 As illustrated in Figures 52 and 54, the preprocessing step may include incorporating the shape of the joint J into the shape S containing the first workpiece 91, based on the nesting data file F3 and the joint data JD. Incorporating the shape of the joint J into the shape S containing the first workpiece 91 may be performed by the CAD / CAM device 18a or by the control device 6 (more specifically, the computer 60) described above. 【0322】 The preprocessing step may include extracting the shape of the first workpiece 91 (in other words, the first shape S1) and the shape of the second workpiece 92 separated from the first workpiece 91 (in other words, the second shape S2) from the shape data SH of the shape S which includes the first workpiece 91 and the joint portion J (in other words, the extraction step described in the first embodiment). 【0323】 As illustrated in Figures 52 and 54, the preprocessing step may include deriving the center of gravity position G1 of the first workpiece 91 based on first shape data SH1 representing the first shape S1 of the first workpiece 91. The preprocessing step may also include deriving the center of gravity position G2 of the second workpiece 92 based on second shape data SH2 representing the second shape S2 of the second workpiece 92. The deriving of the center of gravity position G1 of the first workpiece 91 and the deriving of the center of gravity position G2 of the second workpiece 92 may be performed by the CAD / CAM device 18a or by the control device 6 (more specifically, the computer 60) described above. 【0324】 After the preprocessing step is performed, a step is performed to determine the positions of the multiple holders 31. This step of determining the positions of the multiple holders 31 may be performed by the control device 6 (more specifically, the computer 60) described above. 【0325】 The step of determining the positions of the multiple holders 31 includes determining the layout of the multiple holders 31 that hold the first workpiece 91 (more specifically, the second layout LA2 described above). 【0326】 The process of determining the positions of the multiple holders 31 includes (1) determining the first position P1 of the first holder 31a that holds the first workpiece 91 based on the first shape S1 of the first workpiece 91 (more specifically, the first shape data SH1 that shows the first shape S1) (in other words, the first position determination process described in the first embodiment), and (2) determining the first shape S1 of the first workpiece 91 (more specifically, the first shape data SH1 that shows the first shape S1) and the first length L1 from the first holder 31a. (3) The process includes determining the second position P2 of the second holder 31b that holds the first workpiece 91 based on (3) the first shape S1 of the first workpiece 91 (more specifically, the first shape data SH1 that shows the first shape S1), the first length L1 from the first holder 31a, and the second length L2 from the second holder 31b, and determining the third position P3 of the third holder 31c that holds the first workpiece 91 based on (3) the first shape S1 of the first workpiece 91 (more specifically, the first shape data SH1 that shows the first shape S1), first holder 31a, and determining the third position P3 of the third holder 31c that holds the first workpiece 91, in other words, the third position determination process. 【0327】 The step of determining the positions of the multiple holders 31 may include determining the layout of the multiple holders 31 that hold the second workpiece 92 (more specifically, the third layout LA3 described above). 【0328】 More specifically, the steps for determining the positions of the multiple holders 31 include: (1) determining the position of one holder (e.g., first holder 31a) that holds a first portion of the second workpiece 92 based on second shape data SH2 indicating the shape of the second workpiece 92; (2) determining the position of one holder that holds a second portion of the second workpiece 92 based on the second shape data SH2 and the length from one holder that holds a first portion of the second workpiece 92; and (3) determining the position of one holder that holds a third portion of the second workpiece 92 based on the second shape data SH2, the length from one holder that holds a first portion of the second workpiece 92, and the length from one holder that holds a second portion of the second workpiece 92. 【0329】 The holder that holds the second part of the second workpiece 92 may be the same as the holder that holds the second part of the first workpiece 91, or it may be different from the holder that holds the second part of the first workpiece 91. The holder that holds the third part of the second workpiece 92 may be the same as the holder that holds the third part of the first workpiece 91, or it may be different from the holder that holds the third part of the first workpiece 91. 【0330】 The step of determining the positions of the multiple holders 31 may include determining the layout of the multiple holders 31 that hold the third workpiece 93 (more specifically, the first layout LA1 described above). 【0331】 After the step of determining the positions of the multiple holders 31 is performed, the transport step is executed. 【0332】 As illustrated in Figure 54, the transport process includes repeatedly executing a cycle that includes changing the layout of the multiple holders 31 relative to the support 33 based on the determined positions of the multiple holders 31, and transporting the workpiece using the multiple holders 31. This cycle is repeated until the transport of the final workpiece is completed. 【0333】 More specifically, the transport process includes changing the layout of the multiple holders 31 relative to the support 33 to a first layout LA1, and transporting the third workpiece 93 while it is being held by the multiple holders 31 arranged in the first layout LA1. As illustrated in Figure 46, transporting the third workpiece 93 may include transporting the third workpiece 93 from the first platform 12 to the third platform 13b. 【0334】 The transport process includes changing the layout of the multiple holders 31 relative to the support 33 from a first layout LA1 to a second layout LA2, and transporting the first workpiece 91 while it is being held by the multiple holders 31 arranged in the second layout LA2. As illustrated in Figure 47, transporting the first workpiece 91 may include transporting the first workpiece 91 from the first platform 12 to the second platform 13a. 【0335】 The transport process includes changing the layout of the multiple holders 31 relative to the support 33 from the second layout LA2 to the third layout LA3, and transporting the second workpiece 92 while it is being held by the multiple holders 31 arranged in the third layout LA3. As illustrated in Figure 48, transporting the second workpiece 92 may include transporting the second workpiece 92 from the first platform 12 to the second platform 13a. 【0336】 (Program PG) In the embodiments, program PG is a program that causes a computer (e.g., control device 6) to execute a method for determining the positions of three or more holders in the first embodiment, or a workpiece transport method in the fourth embodiment. Since the method for determining the positions of three or more holders in the first embodiment and the workpiece transport method in the fourth embodiment have already been described, a repetitive explanation of these methods will be omitted. 【0337】 The program PG in the embodiment is a program for causing a computer to execute a method comprising: (1) determining a first position P1 of a first holder 31a that holds the first workpiece 91 based on a first shape S1 of the first workpiece 91 (more specifically, a first shape data SH1 that shows the first shape S1); (2) determining a second position of a second holder 31b that holds the first workpiece 91 based on a first shape S1 of the first workpiece 91 (more specifically, a first shape data SH1 that shows the first shape S1) and a first length L1 from the first holder 31a; and (3) determining a third position P3 of a third holder 31c that holds the first workpiece 91 based on a first shape S1 of the first workpiece 91 (more specifically, a first shape data SH1 that shows the first shape S1), a first length L1 from the first holder 31a, and a second length L2 from the second holder 31b. 【0338】 When "K" is defined as any natural number greater than or equal to 3 (for example, "K" is 3, 4, 5, 6, 7, 8, 9, ...), the program PG in the embodiment may be a program that causes a computer to execute a method further comprising the step of determining the "K+1" position of the "K+1" holder that holds the first workpiece 91, based on the first shape S1 of the first workpiece 91 (more specifically, the first shape data SH1 representing the first shape S1) and the lengths from each of the three already positioned "K" holders. For example, when "K" = 4, the program PG in the embodiment may be a program that causes a computer to execute a method further comprising the step of determining the fourth position P4 of the fourth holder that holds the first workpiece 91, based on the first shape S1 of the first workpiece 91 (more specifically, the first shape data SH1 representing the first shape S1) and the lengths from each of the three already positioned holders, namely the first holder 31a, the second holder 31b, and the third holder 31c. 【0339】 In this embodiment, the program PG includes the steps of: (1) determining a first position P1 of a first holder 31a that holds the first workpiece 91 based on a first shape S1 of the first workpiece 91 (more specifically, first shape data SH1 that shows the first shape S1); (2) determining a second position of a second holder 31b that holds the first workpiece 91 based on the first shape data SH1 and a first length L1 from the first holder 31a; (3) determining a third position P3 of a third holder 31c that holds the first workpiece 91 based on the first shape data SH1, a first length L1 from the first holder 31a and a second length L2 from the second holder 31b; and (4) determining a plurality of holders arranged in the first layout LA1. The method (i.e., workpiece transport method) may be a program to cause a computer (more specifically, a control device 6) to execute a method (i.e., a workpiece transport method) comprising: (5) transporting the third workpiece 93 while it is being held by the holder 31; (6) changing the layout of the plurality of holders 31 on the support 33 from a first layout LA1 to a second layout LA2 such that the first holder 31a is placed at a first position P1, the second holder 31b is placed at a second position P2, and the third holder 31c is placed at a third position P3; and (7) transporting the first workpiece 91 while it is being held by the plurality of holders 31 arranged in the second layout LA2. In this case, the program PG in the embodiment may include the control program PM1 described above. 【0340】 The method described in the preceding paragraph may also include the steps of (7) changing the layout of the plurality of holders 31 relative to the support 33 from a second layout LA2 to a third layout LA3, and (6) transporting the second workpiece 92 while it is being held by the plurality of holders 31 arranged in the third layout LA3. Additionally, the method described in the preceding paragraph may include transporting the plurality of workpieces 9, including the first workpiece 91, the second workpiece 92, and the third workpiece 93, from a first platform 12 to a plurality of sorting areas (e.g., a second platform 13a and a third platform 13b) using the plurality of holders 31 so that the plurality of workpieces 9 are sorted into a plurality of groups. 【0341】 The program PG in the embodiment may be a program that causes a computer (more specifically, a control device 6) to execute a method further comprising the step of laser processing a raw material workpiece RW so that a plurality of workpieces, including a first workpiece 91, a second workpiece 92, and a third workpiece 93, and scrap material LM are formed from the raw material workpiece RW. In this case, the program PG in the embodiment may include the processing program PM2 described above. 【0342】 The memory (e.g., memory 62) mentioned in the first, second, or third embodiment may be a non-volatile storage medium (more specifically, a non-temporary computer-readable storage medium) on which the above-described program PG is recorded. The non-volatile storage medium on which the above-described program PG is recorded may be a portable storage medium 62M, as illustrated in Figure 55. 【0343】 In the embodiment, the program PG, when executed by the computer 60 (for example, the control device 6), has the same effect as the method for determining the positions of three or more holders in the first embodiment, or the workpiece transport method in the fourth embodiment. 【0344】 The present invention is not limited to the embodiments or modifications described above, and it is clear that each embodiment or modification can be appropriately modified or changed within the scope of the technical concept of the present invention. Furthermore, the various technologies used in each embodiment or modification can be applied to other embodiments or other modifications, as long as no technical inconsistencies arise. In addition, any optional additional configurations in each embodiment or modification can be omitted as appropriate. 【0345】 For example, the laser processing system 100 in the third embodiment may include a second workpiece transport device 19 (see Figure 56) that transports a plurality of workpieces 95 formed from the second raw material workpiece RW2 and scrap material LM2 formed from the second raw material workpiece RW2 all at once. The second workpiece transport device 19 is a separate device from the workpiece transport device 10. When the laser processing system 100 includes the workpiece transport device 10 and the second workpiece transport device 19, it is possible to select between individual transport of workpieces and transport of the plurality of workpieces 95 and scrap material LM2 all at once. The second workpiece transport device 19 may include a fork 19f that supports the plurality of workpieces 95 formed from the second raw material workpiece RW2 and the scrap material LM2 formed from the second raw material workpiece RW2 from below. [Explanation of Symbols] 【0346】 3...Attachment, 3b...First attachment, 3c...Second attachment, 3d...Third attachment, 3e...Fourth attachment, 3f...Fifth attachment, 3g...Sixth attachment, 3h...Seventh attachment, 3i...Eighth attachment, 4...Moving device, 6...Control device, 9...Workpiece, 10, 10A...Workpiece transport device, 12...First platform, 13a...Second platform, 13b...Third platform, 15...Attachment support device, 15b...First support device, 15c...Second support device, 15d...Third support device, 15e...Fourth support device 16…Holding device, 18…Power supply device, 18…Second computer, 18a…CAD / CAM device, 19…Second workpiece transport device, 19f…Fork, 31, 31-1, 31-2…Holding body, 31a…First holder, 31b…Second holder, 31c…Third holder, 31d…Fourth holder, 31e…Fifth holder, 31f…Sixth holder, 31g…Seventh holder, 31h…Eighth holder, 31i…Ninth holder, 32…Movable holder, 32a…Electromagnet, 33…Support, 35…Plate support device, 41…Articulated robot, 42…Robot moving device, 60…Computer, 62…Memory, 62M… Storage medium, 63... Arithmetic unit, 63a... Processor, 64... Communication circuit, 66... ​​Input device, 66k... Keyboard, 67... Display, 68... Bus, 70... First control unit, 71... Second processor, 72... Second memory, 74... Second communication circuit, 76... Second input device, 76t... Touch panel, 77... Second display, 78... Bus, 80... Second control unit, 81... Third processor, 82... Third memory, 84... Third communication circuit, 86... Third input device, 86b... Button, 86t... Touch panel, 87... Third display, 88... Bus, 91... First work, 91-1... First w 91-2...First part of the first workpiece, 91-3...Third part of the first workpiece, 91-4...Fourth part of the first workpiece, 91e...Edge, 91m...First main surface, 92...Second workpiece, 93...Third workpiece, 94...Small workpiece, 95...Workpiece, 100...Laser processing system, 101...Laser processing device, 102...Laser irradiation device, 102a...Laser head, 103...Head moving device, 106...Workpiece support device, 121...First support base, 121b...Pallet moving device, 131a...Second support base, 131b...Third support base, 151b...Gripping device, 311a...First electromagnet,311b...2nd electromagnet, 311c...3rd electromagnet, 311d...4th electromagnet, 311e...5th electromagnet, 311f...6th electromagnet, 311g...7th electromagnet, 311h...8th electromagnet, 311i...9th electromagnet, 312b...1st mounting electromagnet, 312c...2nd mounting electromagnet, 314b...1st insulator, 314c...2nd insulator, 315b...1st spring, 315c...2nd spring, 331...plate, 331m...main surface, 511a...1st cable, 511b...2nd cable, 511c...3rd cable, 512b...cable, 512c...cable, 531...movable holder moving device, 531s...E A cylinder, 532... cable, 911... plate-shaped workpiece, 1311a... one side of the second platform, 1312a... the other side of the second platform, AM... arm, AM1... tip arm, BL... boundary where multiple parts come into contact, BR... allowable area, BT... bolt, C1... central axis, CA1... first candidate position, CA2... second candidate position, CA3... third candidate position, CT... notch, DE... sorting data, DE1... first pickup position data, DE2... first release position data, DT1... data indicating the centroid of the shape containing the first workpiece, EG... edge, EL... face element, EL1...First face element, EL2...Second face element, F1...Drawing data file for raw material workpiece, F2...Drawing data file for multiple parts, F3...Nesting data file, FR...Area prone to bending, G...Centroid of the shape including the first workpiece, G1...Center of gravity position of the first workpiece, G2...Center of gravity position of the second workpiece, G3...Center of gravity position of the third workpiece, GD1...First center of gravity data, GD2...Second center of gravity data, HP...Hole, J...Joint, JD...Joint data, JT...Joint, LA1...First layout, LA2...Second layout, LA3...Third layout, LB...Laser, LM...Scrap material, LM2...Scrap material, LR1...First area, LR2...Second area, M1...Layout change mode, M1-1...First position change mode, M2-1...First transport mode, M2-2...Second transport mode, M2-3...Third transport mode, M3...Sorting mode, MA...Auxiliary map, MB...Composite map, MG...Margin distance, MP1...First map, MP2...Second map, MP3...Third map, MP4...Fourth map, MT...Motor, ND...Nesting data, OP...Opening, P1...First position, P2...Second position, P2'...Second position, P3...Third position, P4...Fourth position, P5...Fifth positionPA1...shortest path, PA2...shortest path, PA3...shortest path, PC...coordinate, PC1...first coordinate, PC2...second coordinate, PC3...third coordinate, PC4...fourth coordinate, PC5...fifth coordinate, PD...part, PG...program, PM1...control program, PM2...machining program, PT1...first pallet, PT2...second pallet, PT3...third pallet, Q1...pickup position, Q2...release position, Q3...pickup position, Q4...release position, Q5...pickup position, Q6...release position, RG1...surrounding area, RG2...surrounding area, RT...area not on the first main surface of the first workpiece, RW...raw material workpiece, RW2...second raw material workpiece -k, S...Shape containing the first workpiece, S1...First shape, S2...Second shape, SH...Shape data, SH1...First shape data, SH2...Second shape data, SH3...Third shape data, SL...Slit, SS...Slit line, ST1...First step, ST2...Second step, ST3...Third step, ST4...Fourth step, ST5...Fifth step, ST101...Pre-processing step, ST102...Step to determine the positions of multiple holders, ST103...Transportation step, T1...First mounting position, T2...Second mounting position, U1...First processing, U2...Second processing, U3...Third processing, U4...Fourth processing, U5...Fifth processing, V1...First value, V2...Second value,

Claims

[Claim 1] A step of determining a first position of a first holder that holds the first main surface of a first workpiece by magnetic force or vacuum attraction force while being supported by a support, based on the shape of a first workpiece which is a plate-shaped workpiece, A step of determining the second position of the second holder, which holds the first main surface of the first workpiece by magnetic force or vacuum attraction force while being supported by the support, based on the shape of the first workpiece and the first length from the first holder at the first position, A step of determining the third position of the third holder that holds the first main surface of the first workpiece by magnetic force or vacuum attraction force while supported by the support, based on the shape of the first workpiece, the first length from the first holder at the first position, and the second length from the second holder at the second position. It is equipped with, The steps for determining the second position and the third position are performed by a computer. The first, second, and third positions represent the relative positions of the first holder, the second holder, and the third holder with respect to the first workpiece, respectively. A method for determining the positions of three or more holders. [Claim 2] The step of determining the third position is: This includes determining the third position such that the smaller of the length from the first position to the third position and the length from the second position to the third position is substantially maximized. A method for determining the positions of three or more holders as described in claim 1. [Claim 3] The process comprises generating a first map showing the distribution of the first length from the first holder at the first position, The step of determining the second position includes determining the second position based on the first map. A method for determining the positions of three or more holders according to claim 1 or 2. [Claim 4] The process includes generating a second map which is a combination of the distribution of the first length from the first holder at the first position and the distribution of the second length from the second holder at the second position, The step of determining the third position includes determining the third position based on the second map. A method for determining the positions of three or more holders according to claim 1 or 2. [Claim 5] The step of determining the first position includes determining the first position based on the center of gravity of the first workpiece. A method for determining the positions of three or more holders according to claim 1 or 2. [Claim 6] If the first workpiece has an opening, the first length from the first holder at the first position is the length that bypasses the opening. A method for determining the positions of three or more holders according to claim 1 or 2. [Claim 7] The step of determining the second position includes determining the second position based on the shape of the first workpiece, the first length, and the condition of the region of the first workpiece that is within a predetermined distance from each point on the shape of the first workpiece. A method for determining the positions of three or more holders according to claim 1 or 2. [Claim 8] The process comprises dividing the shape of the first workpiece into a plurality of surface elements, The first map is generated based on the length from the first holder at the first position to each of the plurality of face elements. A method for determining the positions of three or more holders as described in claim 3. [Claim 9] The process includes the step of displaying the plurality of surface elements on a display in different colors according to the length from the first holder at the first position to each of the plurality of surface elements. A method for determining the positions of three or more holders as described in claim 8. [Claim 10] If the second holder positioned at the determined second position overlaps with the hole in the first workpiece, the second position is corrected so that the distance from the first holder at the first position to the second holder at the second position is shortened until the overlap between the second holder and the hole is resolved. A method for determining the positions of three or more holders according to claim 1 or 2. [Claim 11] A step of acquiring shape data of the shape that includes the first workpiece, A step of extracting the shape of the first workpiece and the shape of the second workpiece, which is a second plate-shaped workpiece separated from the first workpiece, from the acquired shape data. Equipped with A method for determining the positions of three or more holders according to claim 1 or 2. [Claim 12] The method comprises the step of determining the position of the other at least one holder such that the first holder located at the first position, the second holder located at the second position, and the third holder located at the third position simultaneously hold the first workpiece, and the second workpiece, which is a second plate-shaped workpiece separated from the first workpiece, is held by the other at least one holder. A method for determining the positions of three or more holders according to claim 1 or 2. [Claim 13] A step of determining a first position of a first holder that holds the first main surface of a first workpiece by magnetic force or vacuum attraction force while being supported by a support, based on the shape of a first workpiece which is a plate-shaped workpiece, A step of determining the second position of the second holder, which holds the first main surface of the first workpiece by magnetic force or vacuum attraction force while being supported by the support, based on the shape of the first workpiece and the first length from the first holder at the first position, A step of determining the third position of the third holder that holds the first main surface of the first workpiece by magnetic force or vacuum attraction force while supported by the support, based on the shape of the first workpiece, the first length from the first holder at the first position, and the second length from the second holder at the second position. It is equipped with, The first, second, and third positions represent the relative positions of the first holder, the second holder, and the third holder with respect to the first workpiece, respectively. A program that instructs a computer to execute a method. [Claim 14] A plurality of holders including a first holder, a second holder, and a third holder, A moving device for moving a support that supports the plurality of holders, A memory that stores the shape of the first workpiece, which is a plate-shaped workpiece, A computing device that determines, based on the shape of the first workpiece, the first position of the first holder that holds the first main surface of the first workpiece by magnetic force or vacuum attraction while supported by the support; determines, based on the shape of the first workpiece and a first length from the first holder at the first position, the second position of the second holder that holds the first main surface of the first workpiece by magnetic force or vacuum attraction while supported by the support; and determines, based on the shape of the first workpiece, a first length from the first holder at the first position, and a second length from the second holder at the second position, the third position of the third holder that holds the first main surface of the first workpiece by magnetic force or vacuum attraction while supported by the support. It is equipped with, The first, second, and third positions represent the relative positions of the first holder, the second holder, and the third holder with respect to the first workpiece, respectively. Workpiece transport device. [Claim 15] A laser processing apparatus that forms multiple workpieces, including a first workpiece which is a plate-shaped workpiece, from a raw material workpiece by irradiating the raw material workpiece with a laser, A workpiece transfer device comprising a plurality of holders including a first holder, a second holder, and a third holder, and a moving device for moving a support that supports the plurality of holders, and using the plurality of holders including the first holder, the second holder, and the third holder to transfer the plurality of workpieces, A memory for storing the shape of the first workpiece, A computing device that determines, based on the shape of the first workpiece, the first position of the first holder that holds the first main surface of the first workpiece by magnetic force or vacuum attraction while supported by the support; determines, based on the shape of the first workpiece and a first length from the first holder at the first position, the second position of the second holder that holds the first main surface of the first workpiece by magnetic force or vacuum attraction while supported by the support; and determines, based on the shape of the first workpiece, a first length from the first holder at the first position, and a second length from the second holder at the second position, the third position of the third holder that holds the first main surface of the first workpiece by magnetic force or vacuum attraction while supported by the support. It is equipped with, The first, second, and third positions represent the relative positions of the first holder, the second holder, and the third holder with respect to the first workpiece, respectively. Laser processing system.

Images