Welding system, relay vehicle, welding support method and program

Abstract

To suitably lead a cable connected to a welding tool.SOLUTION: A welding system 1 feeds at least one of a wire for welding, power, and shield gas to a torch 121 through a cable CA from a wire feeder 3 and includes: at least one relay vehicle 4 that is movably configured, and relays the cable CA for connecting the torch 121 and the wire feeder 3; and a control device 6. A control part 66 of the control device 6 moves the relay vehicle 4 at an optimal position of the relay vehicle 4 where a lead state of the cable CA is optimized.SELECTED DRAWING: Figure 3

Description

【Technical Field】 【0001】 The present invention relates to a welding system, a relay vehicle, a welding support method, and a program. 【Background Art】 【0002】 Conventionally, for example, a welding robot that performs arc welding while traveling on a base material is known. The welding robot is connected to a wire feeder installed at a distant position via a cable, and a welding wire or the like is supplied from the wire feeder to a welding torch (welding tool). In this type of welding system, it is necessary to appropriately route the cable so that the cable can preferably feed the wire or the like without hindering the movement of the welding robot. 【0003】 As a technique for feeding a fed material (electricity) to a working machine via a cable, for example, in the one described in Patent Document 1, a cable connecting a supply source of the fed material and the working machine is relayed by a relay carriage. Then, the movement of the relay carriage is controlled so that the relay carriage maintains a relative distance from the working machine and does not step on the cable. 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent No. 5791363 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 However, if the relay carriage only moves while maintaining a relative distance from the working machine and does not step on the cable, there may be cases where the fed material in the cable is not preferably fed. For example, due to a steep bend or twist of the cable, the fed material may be difficult to feed, or the cable may pull on the welding robot and hinder its movement. 【0006】 The present invention has been made in view of the above circumstances, and aims to suitably route a cable connected to a welding tool. [Means for solving the problem] 【0007】 The present invention A welding system that supplies at least one of welding wire, power, and shielding material from a source to a welding tool via a cable, A mobile relay vehicle is provided for relaying the cable connecting the welding tool and the supply source, A control means for moving the relay vehicle to the optimal position for optimizing the routing of the aforementioned cables, Equipped with 、 The control means calculates the position of the relay vehicle that minimizes the evaluation parameter corresponding to the bend of the cable as the optimal position. . Furthermore, the present invention is A welding system that supplies at least one of welding wire, power, and shielding material from a source to a welding tool via a cable, A mobile relay vehicle is provided for relaying the cable connecting the welding tool and the supply source, A control means for moving the relay vehicle to the optimal position for optimizing the routing of the aforementioned cables, Equipped with, The control means is Assuming that the aforementioned cable is connected in series at multiple joints, The optimal position of the relay vehicle is calculated to maximize the sum of the distances between each of the multiple joints and the other element closest to that joint. [Effects of the Invention] 【0008】 According to the present invention, a cable connected to a welding tool can be routed efficiently. [Brief explanation of the drawing] 【0009】 [Figure 1] This is a diagram showing a welding system according to an embodiment. [Figure 2] This is a block diagram showing a schematic control configuration of a welding system according to an embodiment. [Figure 3] This is a flowchart showing the flow of the welding support process according to the embodiment. [Figure 4] This diagram conceptually illustrates the contents of the welding support process according to the embodiment. [Figure 5] It is a diagram exemplifying the progress of the welding support process according to an embodiment. [Figure 6] It is a diagram showing a modified example of a wheel of a welding robot or the like according to an embodiment. 【Mode for Carrying Out the Invention】 【0010】 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 【0011】 [Configuration of Welding System] FIG. 1 is a diagram showing a welding system 1 according to the present embodiment, and FIG. 2 is a block diagram showing a schematic control configuration of the welding system 1. As shown in these diagrams, the welding system 1 is for feeding a welding wire or the like to the welding robot 10 and causing the welding robot 10 to perform a welding operation by remote control or automatic driving. Specifically, the welding system 1 includes a welding robot 10, a wire feeder 3, a plurality of relay vehicles 4, a plurality of cameras 5, and a control device 6. 【0012】 The welding robot 10 performs a welding operation on a welding target (for example, a plate material P) while moving freely. Specifically, the welding robot 10 includes a vehicle body 11 and a welding mechanism 12 mounted on the vehicle body 11. The vehicle body 11 includes a frame 111 on which the welding mechanism 12 is mounted and a plurality (for example, four) of wheels 112 that support the frame 111. Each wheel 112 (wheel body) is formed in a spherical shape (spherical shell shape) and is rotatably supported by the frame 111. A drive unit such as a gear motor or the like is connected to each wheel 112. When the drive unit operates and each wheel 112 rotates, the welding robot 10 can travel on an arbitrary surface. 【0013】 The welding mechanism 12 includes a torch (welding torch) 121. The torch 121 is a welding tool that performs welding on a welding target (for example, a plate material P). The torch 121 of the present embodiment performs arc welding by melting a wire (welding filler) by arc discharge. Furthermore, the torch 121 is supported in a displaceable manner and is configured to allow changes in its position and orientation. 【0014】 In addition to the above configuration, the welding robot 10 also includes a communication unit 15 and a control unit 16. The communication unit 15 is a communication device capable of sending and receiving various types of information with the control device 6. The control unit 16 is configured, for example, as a microcomputer, and controls the operation of each part of the welding robot 10 based on operation commands from the control device 6 and a predetermined operation program. 【0015】 The wire feeder 3 is connected to the welding robot 10 via cable CA, and supplies welding wire, power, and shielding gas to the torch 121 of the welding robot 10 through cable CA. The wire feeder 3 is an example of a supply source according to the present invention. The wire feeder 3 is fitted with an electric wire reel 32 on which the wire is wound. The wire wound on the wire reel 32 is unwound from the wire reel 32 and guided through the inside of the cable CA to the tip of the torch 121. The wire feeder 3 is connected to a power supply unit 38 that can supply power. The power supplied from the power supply unit 38 to the wire feeder 3 is then supplied to the torch 121 through power lines inside the cable CA. The wire feeder 3 is also powered by the power supplied from the power supply unit 38. The wire feeder 3 is connected to a gas cylinder 39 filled with shielding gas. The shielding gas supplied from the gas cylinder 39 to the wire feeder 3 is then supplied to the torch 121 through a gas pipe inside the cable CA. The wire feeder 3 is installed in a designated location near the work area, although this is not a particular limitation. 【0016】 Furthermore, the wire feeder 3 includes a communication unit 35 and a control unit 36. The communication unit 35 is a communication device capable of sending and receiving various types of information with the control device 6. The control unit 36 ​​is configured, for example, by a microcomputer, and controls the operation of each part of the wire feeder 3 based on operation commands from the control device 6. The wire feeder 3 only needs to supply at least one of the welding wire, electricity, and shielding gas to the welding robot 10 (torch 121) through cable CA. Furthermore, the shielding material that prevents contact between the molten metal and air is not limited to gas, but may be, for example, in powder form. In other words, the wire feeder 3 may supply a shielding material such as powder to the torch 121 instead of shielding gas. 【0017】 Multiple relay vehicles 4 (four in this embodiment) relay the cable CA connecting the torch 121 and the wire feeder 3. More specifically, the multiple relay vehicles 4 are connected in series to each other via a cable CA section of approximately a fixed length (e.g., less than 10 m), and the two vehicles at the front and rear ends are connected to the torch 121 and the wire feeder 3. The cable CA is a flexible conduit cable that can be bent flexibly. Note that at least one relay vehicle 4 is sufficient. 【0018】 Each relay vehicle 4 is equipped with multiple wheels 41, a communication unit 45, and a control unit 46. Each wheel 41 is configured to change direction and is connected to a drive unit, such as a gear motor. When the drive unit operates and each wheel 41 rotates, the relay vehicle 4 can move on any surface. Furthermore, it is preferable that the wheels 41 be configured to move in all directions, for example, by having a Mecanum wheel or omni-wheel structure. The communication unit 45 is a communication device capable of sending and receiving various types of information with the control device 6. The control unit 46 is configured, for example, with a microcomputer, and controls the operation of each part of the relay vehicle 4 based on operation commands from the control device 6. 【0019】 The multiple cameras 5 are motion capture cameras used to measure the position and orientation of the welding robot 10 and the multiple relay vehicles 4. Each camera 5 is positioned so that the range of movement of the welding robot 10 and the multiple relay vehicles 4 during welding operations is included in the shooting range. Each of the welding robot 10 and the multiple relay vehicles 4 is equipped with multiple markers (not shown) that are detected by the camera 5. By tracking each of these markers with the multiple cameras 5, the position and orientation of each of the welding robot 10 and the multiple relay vehicles 4 are measured. In this embodiment, the "attitude" of the welding robot 10 or relay vehicle 4 refers to its orientation in a plan view (corresponding to its bearing when the plane of movement is the horizontal plane). However, it may also refer to its three-dimensional attitude. 【0020】 The control device 6 provides integrated control of the welding system 1 and is composed of, for example, a personal computer. Specifically, the control device 6 comprises an input unit 62, a display unit 63, a communication unit 64, a storage unit 65, and a control unit 66. 【0021】 The input unit 62 is an operating means that allows the user to perform various operations to operate the control device 6, and includes, for example, a pointing device such as a mouse or a keyboard. The display unit 63 is composed of, for example, a liquid crystal display, an organic EL display, or other display, and displays various information based on display signals from the control unit 66. The display unit 63 may also be a touch panel that also serves as part of the input unit 62. The communication unit 64 is a communication device capable of sending and receiving various types of information between the welding robot 10, the wire feeder 3, the relay vehicle 4, and the camera 5. 【0022】 The memory unit 65 is a memory composed of RAM (Random Access Memory) and ROM (Read Only Memory), and stores various programs and data, as well as functioning as a workspace for the control unit 66. In this embodiment, the memory unit 65 stores a program for executing the welding support processing described later. The control unit 66 is composed of, for example, a CPU (Central Processing Unit) and controls the operation of each part of the control device 6. Specifically, the control unit 66 operates each part of the control device 6 based on the operation content of the input unit 62, and also loads programs pre-stored in the storage unit 65 and executes various processes in cooperation with the loaded programs. 【0023】 [Welding support processing] Next, we will explain the welding support processes that are executed when welding system 1 performs welding. Figure 3 is a flowchart showing the flow of the welding support process, Figure 4 is a diagram conceptually illustrating the contents of the welding support process, and Figure 5 is a diagram illustrating the progress of the welding support process. The welding support process controls the movement of multiple relay vehicles 4 so that the cable CA is routed appropriately without obstructing the movement of the welding robot 10 when the welding robot 10 is moving and performing welding. This welding support process is executed, for example, by the control unit 66 of the control device 6 reading the relevant program from the storage unit 65 and loading it based on user operation. In this scenario, the welding robot 10 moves along one of the plate materials P with multiple relay vehicles 4 and performs groove butt welding on two plate materials P using arc welding (see Figure 5). 【0024】 As shown in Figure 3, when the welding support process is executed, the control unit 66 of the control device 6 first starts the welding work by the welding robot 10 (step S1). The control unit 66 transmits operation commands to the welding robot 10 so that it operates according to a preset movement path and welding timing. The control unit 16 of the welding robot 10 operates each part based on the received operation commands. The operation control of the welding robot 10 may be autonomous control based on information acquired by the welding robot 10 itself or by externally installed sensors, or by remote operation by a human. 【0025】 Next, the control unit 66 acquires the current position and orientation of the welding robot 10 and the multiple relay vehicles 4 (step S2). In this embodiment, the current position and orientation of the welding robot 10 and each relay vehicle 4 are measured by motion capture, which involves capturing images of markers on the welding robot 10 and each relay vehicle 4 using multiple cameras 5 and processing the images. 【0026】 Next, the control unit 66 estimates the current routing state (routing shape) of the cable CA from the wire feeder 3 to the welding robot 10 based on the position and orientation information acquired in step S2 (step S3). In this step, it is assumed that the cable CA is routed smoothly from the welding robot 10 to the wire feeder 3, passing through the current positions of each relay vehicle 4. That is, the current routing state of the cable CA is determined to be the state in which the strain energy due to bending in a plan view is minimized, while corresponding to the current position and orientation of the welding robot 10 and each relay vehicle 4. Specifically, as shown in Figure 4(a), the cable CA is assumed to be a multi-joint mechanism connected in series by joints L of multiple cylindrical links, and the distribution of the bending angle θ at each joint L is calculated when the sum of the squares of the bending angles θ at each joint L is minimized. It is assumed that the direction of the cable CA extending from the wire feeder 3 is fixed. 【0027】 Next, the control unit 66 calculates the position (optimal position) of each relay vehicle 4 that will result in the optimal routing state of the cable CA, using the current routing state estimated in step S3 as the initial value (step S4). Here, the optimal routing state is defined as the condition in which the cable CA smoothly connects from the welding robot 10 to the wire feeder 3 without being constrained by the relay vehicle 4, while avoiding contact with other elements. That is, as shown in Figure 4(b), the current bending angle θ of the cable CA is used as the initial value, and the distribution of the bending angle θ of the cable CA from the welding robot 10 to the wire feeder 3 when the strain energy of the cable CA (sum of the squares of the bending angles θ at each joint L) and the probability of the cable CA contacting other elements are minimized is determined as the optimal routing state (shape shown by a solid line in the figure). The position of the relay vehicle 4 at this time is then calculated as the optimal position. To evaluate the probability of contact of the cable CA, a parameter is added that maximizes the sum of the distances between each joint L of the cable CA and the nearest other element. Other elements include other joints L other than the joint L in question, the welding robot 10, the relay vehicle 4, and the wire feeder 3, but other obstacles (or potential obstacles) within the work area may also be included. 【0028】 Furthermore, the evaluation parameters to be minimized in step S4 may include not only the strain energy of cable CA and the possibility of contact with cable CA, but also the change in the current position of cable CA (joint L). This allows for smoother changes by suppressing temporal discontinuities. Furthermore, the strain energy of cable CA as an evaluation parameter is not limited to the above, as long as it corresponds to the bending angle θ of cable CA (joint L). The same applies to the possibility of contact of cable CA. Furthermore, since the position and orientation of the relay vehicle 4 are free in the calculation of step S4, it is best to treat the relay vehicle 4 as joint L. Furthermore, the position and orientation of the welding robot 10 in step S4 may be those of a predetermined time in the future. The future position and orientation of the welding robot 10 can be calculated from the known movement path and velocity of the welding robot 10. 【0029】 Next, the control unit 66 moves each relay vehicle 4 to the optimal position calculated in step S4 (step S5). As a result, as shown in Figure 4(c), the cable CA can be routed in an optimal manner, smoothly connecting the welding robot 10 and the wire feeder 3 while avoiding contact with other elements. 【0030】 Next, the control unit 66 determines whether or not to terminate the welding support process (step S6). If it determines not to terminate the process (step S6; No), it proceeds to step S2 described above and continues the welding work. Then, each relay vehicle 4 moves sequentially to a new optimal position in accordance with the movement of the welding robot 10. As a result, as shown in Figures 5(a) to (d), for example, the welding work can be performed while maintaining the cable CA in an optimal routing state that smoothly connects the welding robot 10 and the wire feeder 3 while avoiding contact with other elements. On the other hand, if in step S6 it is determined that the welding support process should be terminated, for example, due to the completion of welding work (step S6; Yes), the control unit 66 terminates the welding support process. 【0031】 [Technical effects of this embodiment] As described above, according to this embodiment, the relay vehicle 4, which relays the cable CA connecting the torch 121 and the wire feeder 3, moves to an optimal position that optimizes the routing of the cable CA. This allows the cable CA connected to the torch 121 to be routed appropriately. 【0032】 Furthermore, according to this embodiment, the position of the relay vehicle 4 that minimizes the evaluation parameter corresponding to the bending angle θ of the cable CA is calculated as the optimal position of the relay vehicle 4. This allows the cable CA to be routed in a way that smoothly connects the welding robot 10 and the wire feeder 3. Consequently, it is possible to prevent situations where the bending or twisting of the cable CA obstructs the passage of the wire, or where the movement of the welding robot 10 is hindered by being pulled by the cable CA. 【0033】 Furthermore, according to this embodiment, assuming that the cable CA is connected in series by multiple joints L, the position of the relay vehicle 4 that maximizes the sum of the distances between each joint L and the other element closest to it is calculated as the optimal position of the relay vehicle 4. This allows the cables to be routed in a way that avoids contact between cables CA themselves, as well as contact between cables CA and relay vehicles 4, welding robots 10, etc. 【0034】 [others] Although embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above. For example, in the above embodiment, step S3 of the welding support process is used to estimate the current routing state (bending angle θ) of the cable CA. However, if the routing state (position and shape) of the cable CA can be directly measured, for example, by images acquired from camera 5, then such measurement may be performed in step S3. 【0035】 Furthermore, it is preferable that each wheel 112 of the welding robot 10 and each wheel 41 of the relay vehicle 4 be configured to be able to adhere to the ground (wall surface) by magnetic force or the like. In this case, as shown in Figure 6, each wheel 112 (or wheel 41) only needs to have a magnet 19 (magnetic force generating means) built into it. The magnet 19 is configured so that its magnetic pole direction (direction of attractive force generation) can be changed independently of the rotation of the wheel 112 (outer shell) for movement. Specifically, the magnet 19 is fixed via a holder 192 to a magnet drive shaft 191 which is arranged along the central axis Ax of the wheel 112. The magnet drive shaft 191 is supported so as to be rotatable relative to the wheel 112 and is connected to a magnet drive motor 193 on the outside of the wheel 112. On the outside of the wheel 112 opposite to the magnet drive motor 193, a drive unit 194 is connected to the wheel 112 so as to rotate the wheel 112 around the central axis Ax. This configuration allows the magnet 19 to exert its attractive force in a direction independent of the rotation of the wheel 112. In other words, the magnet 19 generates a magnetic force (attractive force) perpendicular to the contact surface of the wheel 112, providing traction for movement. Furthermore, the wheel 112 can be attracted to a metal wall and travel along that wall. The magnetic force generating means built into each wheel 112 may be a permanent magnet or an electromagnet, as long as the direction of the magnetic poles can be changed. 【0036】 Furthermore, in the above embodiment, the positions of multiple relay vehicles 4 are controlled, but in addition to the relay vehicles 4, the wire feeder 3 may also be configured to be movable and its position controlled in the same way as the relay vehicles 4. In this case, it is preferable that the wheels of the wire feeder 3 are also configured to be able to be attracted to the ground (wall surface) by magnetic force or the like. In this case, the wire feeder 3 may also be equipped with a power battery and / or a gas cylinder, from which power and / or gas may be supplied to the welding robot 10. 【0037】 Furthermore, in the above embodiment, the position and orientation of the welding robot 10 and each relay vehicle 4 are acquired by motion capture, but the method is not particularly limited as long as it is possible to acquire such position and orientation. For example, information acquisition means such as a camera or LiDAR (Light Detection and Ranging) may be mounted on each relay vehicle 4 and the welding robot 10, and each of them may acquire information on other relay vehicles 4 or welding robots 10 adjacent to the front and rear. Alternatively, position information may be acquired by GNSS (Global Navigation Satellite System), and orientation information may be acquired by gyro sensors, acceleration sensors, etc. 【0038】 In the above embodiment, the cable CA is connected to the torch 121 mounted on the welding robot 10. However, the welding tool to which the cable according to the present invention is connected is not limited to the one mounted on the welding robot, and may be mounted on a simple moving carriage (one that moves on a rail), or may be one that is handled or remotely controlled by a person. Further, the welding tool according to the present invention is not limited to a welding torch as long as it supplies at least one of a welding wire, electric power, and a shielding material to perform welding. 【0039】 In the above embodiment, the control device 6 mainly controls the entire welding system 1. However, the control mode of the welding system 1 is not limited to this. For example, each of the welding robot 10 and the plurality of relay vehicles 4 may be autonomously controlled by a program or the like, or any one of them may control the rest. Also, the welding performed by the welding robot is not limited to that of this embodiment as long as it winds the cable connected to the torch (welding tool). 【0040】 In addition, the details shown in the above embodiment can be appropriately changed without departing from the gist of the invention. 【Explanation of Reference Numerals】 【0041】 1 Welding system 3 Wire feeder (source) 4 Relay vehicle 5 Camera 6 Control device (control means) 10 Welding robot 19 Magnet (magnetic force generating means) 112 Wheel 121 Torch (welding tool) CA Cable L Joint P Plate material θ Bend angle

Claims

[Claim 1] A welding system that supplies at least one of welding wire, power, and shielding material from a power source to a welding tool via a cable, A movable relay vehicle is provided for relaying the cable connecting the welding tool and the supply source, A control means for moving the relay vehicle to the optimal position for optimizing the routing of the aforementioned cables, Equipped with, The control means calculates the position of the relay vehicle that minimizes the evaluation parameter corresponding to the bend of the cable as the optimal position. Welding system. [Claim 2] A welding system for supplying at least one of welding wire, power, and shielding material from a supply source to a welding tool via a cable, A movable relay vehicle is provided for relaying the cable connecting the welding tool and the supply source, A control means for moving the relay vehicle to the optimal position for optimizing the routing of the aforementioned cables, Equipped with, The control means is Assuming that the aforementioned cable is connected in series at multiple joints, The optimal position of the relay vehicle is calculated to maximize the sum of the distances between each of the multiple joints and the other element closest to that joint. Welding system. [Claim 3] The control means is Based on the current position and orientation of the relay vehicle, the current bend of the cable is calculated. Using the current bend as an initial value, the cable routing state that minimizes the evaluation parameter is determined. The welding system according to claim 1. [Claim 4] The welding robot, which has the aforementioned welding tool and is configured to be movable, The welding system according to claim 1 or claim 2. [Claim 5] Each of the welding robot and the relay vehicle is equipped with wheels that incorporate a magnetic force generating means capable of changing the direction of the magnetic poles. The welding system according to claim 4. [Claim 6] A relay vehicle that relays a cable connecting a welding tool and a supply source to deliver at least one of welding wire, power, and shielding material to the welding tool, It is configured to be movable, The cable is controlled to move to an optimal position that optimizes the routing of the cable. The position that minimizes the evaluation parameter corresponding to the bending angle of the cable is calculated as the optimal position. Broadcast vehicle. [Claim 7] A relay vehicle that relays a cable connecting a welding tool and a supply source to supply at least one of welding wire, power, and shielding material to the welding tool, It is configured to be movable, The cable is controlled to move to an optimal position that optimizes the routing of the cable. Assuming that the aforementioned cable is connected in series at multiple joints, the optimal position is calculated as the position that maximizes the sum of the distances between each of the multiple joints and the other element closest to that joint. Broadcast vehicle. [Claim 8] A welding support method for a welding system that supplies at least one of welding wire, power, and shielding material from a power source to a welding tool via a cable, The welding system is configured to be movable and includes at least one relay vehicle that relays the cable connecting the welding tool and the supply source, The control means moves the relay vehicle to the optimal position for optimizing the routing of the cable, The control means calculates the position of the relay vehicle that minimizes the evaluation parameter corresponding to the bend of the cable as the optimal position. Welding support method. [Claim 9] A welding support method for a welding system, comprising supplying at least one of welding wire, power, and shielding material from a supply source to a welding tool via a cable, The welding system is configured to be movable and includes at least one relay vehicle that relays the cable connecting the welding tool and the supply source, The control means moves the relay vehicle to the optimal position for optimizing the routing of the cable, The control means is Assuming that the aforementioned cable is connected in series at multiple joints, The optimal position of the relay vehicle is calculated to maximize the sum of the distances between each of the multiple joints and the other element closest to that joint. Welding support method. [Claim 10] A program for a welding system that supplies at least one of welding wire, power, and shielding material from a source to a welding tool via a cable, The welding system is configured to be movable and includes at least one relay vehicle that relays the cable connecting the welding tool and the supply source, Computers, Control means for moving the relay vehicle to the optimal position for optimizing the routing of the aforementioned cables, To make it function as, The control means calculates the position of the relay vehicle that minimizes the evaluation parameter corresponding to the bend of the cable as the optimal position. program. [Claim 11] A program for a welding system that supplies at least one of welding wire, power, and shielding material from a source to a welding tool via a cable, The welding system is configured to be movable and includes at least one relay vehicle that relays the cable connecting the welding tool and the supply source, Computers, Control means for moving the relay vehicle to the optimal position for optimizing the routing of the aforementioned cables, To make it function as, The control means is Assuming that the aforementioned cable is connected in series at multiple joints, The optimal position of the relay vehicle is calculated to maximize the sum of the distances between each of the multiple joints and the other element closest to that joint. program.

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