Control device, welding system, and control method

Abstract

To stabilize a feeding state of a welding wire.SOLUTION: A control device 600 being the control device 600 that performs control of moving a welding wire through the inside of a feeding cable and feeding the welding wire toward a welding position from a wire nozzle fixed to a fixed portion, includes an acquisition unit 631 that acquires sensor information including a load value and a moment value generated in the welding wire fed from the wire nozzle from a sensor, and a wire control unit 632 that controls the position of the tip of the welding wire in the vertical direction and the feeding speed on the basis of the load value and the moment value.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a control device, a welding system, and a control method.

Background Art

[0002] In the automation of welding, labor saving, quality stabilization, suppression of scrap costs, etc. are expected. For example, Patent Document 1 describes that welding is performed while controlling the feeding speed of a welding wire so as to obtain a feeding resistance necessary to extrude the tip of the semi-welded state of the welding wire to the back side of the molten pool under welding conditions suitable for back bead formation.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, in a control device that automatically controls welding, when feeding a welding wire used for welding, if the feeding state of the welding wire is unstable, there is a risk that the positional relationship between the welding wire and the welded portion fluctuates, the welding state of the welding object fluctuates, etc. Therefore, regarding a control device that automatically controls welding, it is desirable to stabilize the feeding state of the welding wire.

[0005] The present disclosure solves the above-described problems, and an object thereof is to provide a control device, a welding system, and a control method for stabilizing the feeding state of a welding wire.

Means for Solving the Problems

[0006] The control device according to the present disclosure is a control device that moves a welding wire inside a feeding cable and controls the feeding of the welding wire from a wire nozzle fixed to a fixing portion toward a welding position, and includes an acquisition unit that acquires sensor information including a load value and a moment value generated in the welding wire fed from the wire nozzle from a sensor, and a wire control unit that controls the position and the feeding speed of the tip portion of the welding wire in the vertical direction based on the load value and the moment value.

[0007] The welding system according to the present disclosure includes a welding device that melts and welds a welding wire, a feeding cable that feeds the welding wire, a wire nozzle that communicates with the feeding cable, and a supply device that has a fixing portion provided between the feeding cable and the wire nozzle and fixed to another member, and feeds the welding wire from the wire nozzle fixed to the fixing portion toward a welding position, a sensor that detects sensor information including a load value and a moment value of the tip portion of the welding wire, and a control device that controls the feeding of the welding wire from the wire nozzle toward the welding position. The control device includes an acquisition unit that acquires sensor information including a load value and a moment value generated in the welding wire fed from the wire nozzle from the sensor, and a wire control unit that controls the position and the feeding speed of the tip portion of the welding wire in the vertical direction based on the load value and the moment value.

[0008] The control method according to the present disclosure is a control method executed by a control device that moves a welding wire inside a feeding cable and controls the feeding of the welding wire from a wire nozzle fixed to a fixing portion toward a welding position, and includes an acquisition step of acquiring sensor information including a load value and a moment value generated in the welding wire fed from the wire nozzle from a sensor, and a wire control step of controlling the position and the feeding speed of the tip portion of the welding wire in the vertical direction based on the load value and the moment value.

Advantages of the Invention

[0009] According to the present disclosure, it is possible to stabilize the feeding state of the welding wire.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

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Figure 4

Figure 5

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Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0011] Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present disclosure will be described in detail. Note that the present disclosure is not limited by this embodiment, and when there are a plurality of embodiments, those configured by combining each embodiment are also included.

[0012] (Embodiment) (Welding System) FIG. 1 is a schematic diagram showing an example of a welding system according to this embodiment. FIG. 2 is a schematic diagram enlarging a part of the supply device shown in FIG. 1.

[0013] As shown in FIG. 1, the welding system 10 supplies the welding wire 700 toward the welding position, and melts and welds the welding wire 700 with the welding device 100. The welding wire 700 is, for example, a filler material. In an example shown in FIG. 1, the welding system 10 includes a welding device 100, a support device 200, a supply device 300, an imaging device 400, a sensor 500, and a control device 600.

[0014] The welding device 100 welds the welding wire 700 and the welding object 1000. The welding device 100 has a welding torch 110. The welding torch 110 is configured to be capable of performing, for example, TIG welding (Tungsten Inert Gas Welding) as arc welding. The welding torch 110 welds the welding wire 700 and the welding object 1000 by utilizing, for example, a discharge phenomenon in the air. When a voltage is applied between the welding electrode 112 and the welding object 1000, the welding torch 110 generates light called an arc, and melts and joins the metal with its heat. The welding torch 110 has a welding head 111 and a welding electrode 112. The welding head 111 is fixed to a case 113. The welding electrode 112 is disposed inside a welding nozzle that penetrates axially inside the welding head 111, and the tip protrudes outside the welding head 111. The welding electrode 112 is made of, for example, tungsten. Note that the welding device 100 may use welding means other than the welding torch 110. The welding device 100 may be configured to perform laser welding, for example, by changing the heat source from an arc to a laser.

[0015] The support device 200 is configured to be movable in the vertical direction with a frame 210 that holds the welding device 100. The support device 200 is electrically connected to the control device 600 and changes the irradiation position of the welding device 100 under the control of the control device 600. In the present embodiment, the support device 200 uses a manipulator.

[0016] The supply device 300 supplies the welding wire 700 toward the welding position. The supply device 300 includes a wire reel portion 310, a feed cable 320, a wire nozzle 330, and a fixing portion 340. The wire reel portion 310 supplies the welding wire 700 and is electrically connected to the control device 600. The wire reel portion 310 is formed in a hollow cylindrical shape by an elastic member so that the welding wire 700 can pass through. The supply of the welding wire 700 by the wire reel portion 310 is controlled by the control device 600, and the welding wire 700 is supplied at a predetermined supply speed. The feed cable 320 supplies the welding wire 700 supplied from the wire reel portion 310 toward the wire nozzle 330 via the fixing portion 340.

[0017] As shown in FIGS. 1 and 2, the wire nozzle 330 is formed in a cylindrical shape capable of sending out the welding wire 700 passing through the inside to the outside, for example, with a member such as metal or synthetic resin. The wire nozzle 330 communicates with the through hole 341 of the fixing portion 340 and is fixed to the fixing portion 340 so as to send out the welding wire 700 supplied from the feed cable 320 toward the welding position. The wire nozzle 330 protrudes from the fixing portion 340 toward the welding position and communicates with the feed cable 320 via the fixing portion 340.

[0018] As shown in FIG. 2, in the fixing part 340, the feeding cable 320 is fixed to the first surface 340A, and the wire nozzle 330 is fixed to the second surface 340B. The fixing part 340 has a through hole 341, and the through hole 341 communicates the feeding cable 320 and the wire nozzle 330. Here, when the welding wire 700 is fed, due to the influence of gravity caused by changes in the welding posture and welding state, etc., for example, due to the following reasons (i) to (iii), the feeding cable 320 may move and measurement noise may occur. (i) As welding progresses, the positional relationship between the supply device 300 and the welding torch 110 changes, so the feeding cable 320 connecting them is pulled. (ii) When the welding posture changes, the feeding cable 320 moves due to the influence of gravity. (iii) When the wire feeding starts or the wire feeding amount is changed, the extrusion force or pulling force applied to the welding wire 700 changes and moves inside the feeding cable 320. For example, when the feeding cable 320 has elasticity, when the welding wire 700 passes through the inside of the feeding cable 320, the feeding cable 320 and the welding wire 700 may come into contact and the feeding cable 320 may shake, which may generate measurement noise.

[0019] In this embodiment, the fixing part 340 is fixed to the apparatus main body, the support member, the workbench, etc. so as to suppress the shaking of the feeding cable 320 and suppress the transmission of the shaking of the feeding cable 320 to the wire nozzle 330. By fixing the fixing part 340 to other members, the feeding cable 320 and the wire nozzle 330 are suppressed from shaking. That is, the fixing part 340 can suppress the transmission of the shaking of the feeding cable 320 to the wire nozzle 330 rather than directly connecting the feeding cable 320 and the wire nozzle 330.

[0020] In this embodiment, the fixing part 340 is included in the supply device 300 and is held by a six-axis articulated robot arm (not shown), and can be adjusted to the required position and posture from the control device 600. Thereby, the fixing part 340 can adjust the position and feeding direction of the tip part 710 of the welding wire 700 fed from the wire nozzle 330. Note that the adjusting means for the position and angle of the fixing part 340 may be included in the control device 600 or may be an independent configuration of the welding system 10. In this embodiment, the tip part 710 of the welding wire 700 includes the end part and the tip part of the welding wire 700 protruding from the wire nozzle 330 to the outside, but may be only the tip part or only the end part.

[0021] The imaging device 400 is a device capable of imaging the positional relationship between the tip part 710 (see FIG. 2) of the welding wire 700 and the welding position. As the imaging device 400, for example, a camera, a depth camera, a LiDAR (Light Detection And Ranging), or the like can be used. In this embodiment, the imaging device 400 is attached to the support member and images the welding position irradiated with the laser light. The imaging device 400 is electrically connected to the control device 600 and supplies the captured image data to the control device 600. Then, the control device 600 controls the operations of the welding device 100, the supply device 300, etc. based on the imaging information captured by the imaging device 400.

[0022] The sensor 500 can detect various information that can identify the contact state of the welding wire 700 with the object 1000 to be welded, the position of the tip 710, etc. The sensor 500 includes, for example, a force sensor that can detect contact state information that can identify load values, moment values, etc. of the wire nozzle 330 or the welding wire 700. The sensor 500 may use other sensors such as an acceleration sensor, a load sensor, a strain sensor, etc., or may combine multiple types of sensors. The sensor 500 is provided on the feeding cable 320, the wire nozzle 330, the fixing part 340, etc. so as to be able to detect the load on the welding wire 700 and the moment generated in the welding wire 700. The sensor 500 is electrically connected to the control device 600 and supplies sensor information including the detected various information to the control device 600. Note that the welding system 10 may be provided with one sensor 500 or a plurality of sensors 500 for the supply device 300.

[0023] In this embodiment, the sensor 500 is a force sensor. As shown in FIG. 2, it can detect the moment axis direction M along the left - right direction 910 with respect to the welding wire 700 protruding outward from the wire nozzle 330, and the load axis direction F along the wire nozzle 330. For the moment axis direction M, for example, one direction around the axis of the moment axis direction M of the welding wire 700 can be represented as "M +", and the other direction as "M -". For the load axis direction F, for example, the direction in which the welding wire 700 is pushed toward the wire nozzle 330 can be represented as "F +", and the direction in which it is sent out from the wire nozzle 330 can be represented as "F -". The load value acquired by the force sensor of the sensor 500 is a value obtained by detecting the force with which the welding wire 700 presses against the welding object 1000 and the resultant force when it contacts the welding object 1000 depending on the vertical position of the welding wire 700. The load value acquired by the force sensor of the sensor 500 is a value obtained by detecting the force (reaction) when the welding wire 700 contacts the welding object 1000 depending on the vertical position of the welding wire 700. The moment value acquired by the force sensor of the sensor 500 is a value obtained by detecting the force with which the tip of the welding wire 700 contacts and the welding wire 700 bends. That is, the moment value includes a value indicating the force around the axis of the moment axis direction M (pitch axis) and does not include the component in the load axis direction F.

[0024] In this embodiment, the sensor 500 is disposed near the center of the tip portion 710 of the welding wire 700. Note that it is not limited to this arrangement, and the sensor 500 may be disposed, for example, on the wire nozzle 330 (specifically, on the tip side from the fixing portion 340) or on the fixing portion 340.

[0025] (Control device) Next, an example of the control device 600 of the welding system 10 will be described. Based on the sensor information detected by the sensor 500, the control device 600 controls the operations of the welding device 100, the support device 200, the supply device 300, etc., to perform welding of the welding wire 700 by the welding device 100. Specifically, the control device 600 controls operations such as the irradiation direction and position of the laser light by the welding device 100, the contact state of the welding wire 700 with the welding object 1000, and the imaging position of the imaging device 400 to perform welding.

[0026] In the present embodiment, in automatic TIG welding, the control device 600 controls the positional relationship between the welding electrode 112 of the welding device 100 in the left - right direction and the welding wire 700 by utilizing deep learning on the image of the welding position, and controls the position and feeding speed of the welding wire 700 using the detected wire contact state. The left - right direction is the left direction and the right direction of the welding wire 700 in the plane passing through the welding wire 700.

[0027] The control device 600 determines the suitability of the wire supply speed of the welding wire 700 based on the sensor information including the load value and moment value acquired by the sensor 500. When the control device 600 determines that the load value does not exceed the determination threshold value, it performs control to reduce the wire feeding amount. When the control device 600 determines that the moment value exceeds the determination threshold value, it performs control to raise the tip position of the welding wire 700 until the moment value does not exceed the determination threshold value.

[0028] FIG. 3 is a diagram showing an example of an image captured by the imaging device 400. The image 410 shown in FIG. 3 is image data obtained by the imaging device 400 capturing the welding position 800 including the welding electrode 112 of the welding device 100 and the tip portion 710 of the welding wire 700. The control device 600 can acquire two - dimensional numerical information such as the welding electrode 112, the welding wire 700, the molten pool, and the groove position (gap position) by recognizing the image 410. Note that the molten pool is a pool of molten metal generated by heat such as an arc during welding.

[0029] In the automatic TIG welding method, the vertical position control of the welding wire 700 can determine the contact state by detecting the load caused by the contact between the tip 710 of the welding wire 700 and the object to be welded 1000 from the image 410 obtained by imaging the welding position 800. Also, in the automatic TIG welding method, it has been found that it is difficult to determine the contact state of the tip 710 of the welding wire 700 from the image 410, which is a still image of the welding position 800, with respect to the vertical position control of the welding wire 700. Therefore, it is conceivable to detect the load on the welding wire 700 by determining the contact state between the tip 710 of the welding wire 700 and the molten pool. However, when detecting the load from the welding wire 700 with a torque sensor, the load from the feeding cable 320 of the welding wire 700 is detected as noise. Thus, there is room for improvement in the discrimination accuracy of the vertical posture of the welding wire 700 in the conventional automatic TIG welding method.

[0030] In this embodiment, in the TIG welding method, a technical concept is provided to improve the discrimination accuracy of the contact state of the tip 710 of the welding wire 700.

[0031] FIG. 4 is a diagram for explaining an example of the relationship between the welding wire 700 and the object to be welded 1000. Scene C1 in FIG. 4 schematically shows the fixing part 340 and the upper surface of the welding wire 700. Scene C2 in FIG. 4 schematically shows the fixing part 340 and the side surface of the welding wire 700. Hereinafter, as shown in FIG. 4, the left-right direction 910 is a direction along the welding wire 700 and orthogonal to the load axis direction F, and is a direction for changing the direction of the tip 710 of the welding wire 700 or the direction of the wire nozzle 330. The up-down direction 920 is a direction for moving the tip 710 of the welding wire 700 along the vertical direction. The downward direction is a direction for bringing the tip 710 of the welding wire 700 closer to the object to be welded 1000, and the upward direction is a direction for moving the tip 710 away from the object to be welded 1000. The sensor 500 detects the load value and the moment value generated in the welding wire 700 when the tip 710 of the welding wire 700 contacts the object to be welded 1000. In the present embodiment, each of the load value and the moment value enables six-axis detection by detecting the components in the three-axis directions, and enables discrimination of the entire posture of the welding wire 700.

[0032] FIG. 5 is a schematic block diagram of the control device 600. The control device 600 is a device that controls the welding system 10. The control device 600 is a computer and includes a communication unit 610, a storage unit 620, and a control unit 630 as shown in FIG. 5. The control device 600 is electrically connected to the welding device 100, the support device 200, the supply device 300, the imaging device 400, and the sensor 500.

[0033] The communication unit 610 is a module used by the control unit 630 to communicate with an external device and may include, for example, an antenna. The communication method by the communication unit 610 is wireless communication in the present embodiment, but the communication method may be arbitrary.

[0034] The storage unit 620 is a memory that stores various information such as the calculation content and programs of the control unit 630, and includes, for example, at least one of a main memory device such as a RAM and a ROM, and an external storage device such as an HDD. The storage unit 620 can store programs, determination threshold data, etc. The storage unit 620 stores, for example, sensor information acquired from the sensor 500. The sensor information includes the load value and moment value of the welding wire 700 that moves inside the feeding cable 320 and is fed from the wire nozzle 330 toward the welding position.

[0035] The control unit 630 is an arithmetic unit and includes an arithmetic circuit such as a CPU, for example. The control unit 630 includes an acquisition unit 631 and a wire control unit 632. The control unit 630 reads and executes a program (software) from the storage unit 620 to realize the acquisition unit 631 and the wire control unit 632 and execute their processes. Note that the control unit 630 may execute these processes by one CPU, or may include a plurality of CPUs and execute the processes with these plurality of CPUs. Also, at least a part of the acquisition unit 631 and the wire control unit 632 may be realized by a hardware circuit. Further, the program for the control unit 630 stored in the storage unit 620 may be stored in a recording medium readable by the control device 600.

[0036] The acquisition unit 631 acquires sensor information including the load value and moment value generated in the welding wire 700 that moves inside the feeding cable 320 and is fed from the wire nozzle 330 toward the welding position 800 from the sensor 500. The acquisition unit 631 stores the acquired sensor information in the storage unit 620 in chronological order.

[0037] The wire control unit 632 adjusts the position and feeding speed of the tip 710 of the welding wire 700 in the vertical direction based on the load value and moment value indicated by the sensor information acquired by the acquisition unit 631. The wire control unit 632 compares the moment value of the sensor information with the first condition, and adjusts the position of the tip 710 of the welding wire 700 in the vertical direction based on the comparison result. The first condition includes various conditions such as, for example, a threshold value or a range for determining whether the moment value is normal. In the present embodiment, the first condition includes a normal range for determining whether the moment value is normal. The normal range of the first condition is determined based on the range of the moment values in the normal state detected by the sensor 500 over a certain period of time after the welding starts and the welding becomes stable. When the moment value is higher than the normal range, the wire control unit 632 controls the supply device 300 to raise the position of the welding wire 700, and when the moment value is lower than the normal range, the wire control unit 632 controls the supply device to lower the position of the welding wire 700.

[0038] The wire control unit 632 compares the load value of the sensor information with the second condition, and adjusts the feeding speed of the welding wire 700 based on the comparison result. The second condition includes various conditions such as, for example, a threshold value or a range for determining whether the load value is normal. In the present embodiment, the second condition includes a normal range for determining whether the load value is normal. The normal range of the second condition is determined based on the range of the load values in the normal state detected by the sensor 500 over a certain period of time after the welding starts and the welding becomes stable. When the load value is higher than the normal range, the wire control unit 632 controls the supply device 300 to decrease the feeding speed of the welding wire 700, and when the load value is lower than the normal range, the wire control unit 632 controls the supply device 300 to increase the feeding speed of the welding wire 700.

[0039] In this embodiment, the wire control unit 632 estimates the normal ranges of the moment value and the load value based on the sensor information acquired from the sensor 500 after the welding location has stabilized after the welding device 100 starts welding. Note that the control device 600 may be configured to pre-store the normal ranges of the moment value and the load value in the storage unit 620, or may be configured to acquire the normal ranges corresponding to the types and part numbers of the welding object 1000, the welding wire 700, etc. from a database.

[0040] Based on the image information obtained by imaging the welding position 800, the wire control unit 632 controls the position in the left-right direction 910 between the welding wire 700 and the welding electrode 112 of the welding device 100. For example, the wire control unit 632 utilizes deep learning for the image information obtained by imaging the welding position 800 to adjust the relative positions of the welding electrode 112 and the welding wire 700 to perform position control in the left-right direction 910.

[0041] (Control method of the control device) FIG. 6 is a flowchart showing an example of the processing procedure of the control method executed by the control device. FIG. 7 is a diagram for explaining the normal range of the load value used by the control device. FIG. 8 is a diagram for explaining the normal range of the moment value used by the control device. FIG. 9 is a flowchart showing an example of the position control in the up-down direction 920 shown in FIG. 6. FIG. 10 is a flowchart showing an example of the feed speed control shown in FIG. 6. The processing procedures shown in FIGS. 6, 9, and 10 are realized by the control unit 630 executing a program. The processing procedures shown in FIGS. 6, 9, and 10 are executed by the control unit 630 in a state where the welding location has stabilized after welding is first started.

[0042] As shown in FIG. 6, the control unit 630 of the control device 600 acquires sensor information including the load value and moment value after welding stabilization from the sensor 500 (step S110). For example, the control unit 630 detects, with the sensor 500, the load value and moment value generated in the welding wire 700 over a certain period of time in a state where welding is stable after the start of welding of the welding device 100, and acquires sensor information indicating the detection result from the sensor 500. The state where welding is stable means, for example, a state where stable arc welding becomes possible. When the control unit 630 stores the acquired sensor information in the storage unit 620 in chronological order, the process proceeds to step S120.

[0043] The control unit 630 estimates the ranges of the load value and moment value in the normal state after the start of welding (step S120). FIG. 7 shows the relationship between the difference ΔF (N) from the reference load value of the load detected by the sensor 500 and time (s). As shown in FIG. 7, the control unit 630 extracts the welding stabilization region from the change in load, and estimates the normal range of the load value based on the maximum difference ΔF+ and minimum difference ΔF- of the load in the welding stabilization region. FIG. 8 shows the relationship between the difference ΔM (Nm) from the reference moment value of the moment detected by the sensor 500 and time (s). As shown in FIG. 8, the control unit 630 extracts the welding stabilization region from the change in moment, and estimates the normal range of the moment value based on the maximum difference ΔM+ and minimum difference ΔM- of the moment in the welding stabilization region. Returning to FIG. 6, when the process of step S120 is completed, the control unit 630 proceeds to step S130.

[0044] Note that the process of step S120 described above can be replaced with a process of estimating the normal ranges of the load value and moment value by pre-testing the welding stabilization region or by machine learning. The process of step S120 can be replaced with a process of estimating the normal ranges of the load value and moment value based on information acquired from an external server device, database, etc. of the control device 600.

[0045] The control unit 630 controls the position of the welding wire and the welding electrode in the left - right direction 910 (step S130). The control unit 630 utilizes deep learning on the imaging information captured by the imaging device 400, and relatively moves the welding wire 700 and the welding electrode 112 so that the tip 710 of the welding wire 700 heads towards the welding electrode 112 based on the positional relationship between the welding wire 700 and the welding electrode 112. In this embodiment, the control unit 630 controls the feeding device 300 to move the fixing part 340 in the left - right direction 910, thereby adjusting the orientation of the welding wire 700 fed from the wire nozzle 330 in the left - right direction 910. The control unit 630 may control the welding device 100 to move the position of the welding torch 110 in the left - right direction 910. When the process of step S130 is completed, the control unit 630 proceeds with the process to step S140.

[0046] The control unit 630 performs position control of the welding wire 700 in the up - down direction 920 (step S140). After the positions of the welding wire 700 and the welding electrode 112 in the left - right direction 910 become normal, the control unit 630 controls the position of the tip 710 of the welding wire 700 in the up - down direction 920 based on the moment value detected by the sensor 500.

[0047] For example, the control unit 630 executes the position control process shown in FIG. 9 in the up - down direction 920 to compare the moment value of the sensor 500 with the normal range of the moment value measured after welding stability (step S141). For example, the control unit 630 compares whether the moment value is within the normal range shown in FIG. 8 estimated in step S120, whether the value is larger or smaller than the normal range, and stores the information indicating the comparison result in the storage unit 620. When the process of step S141 is completed, the control unit 630 proceeds with the process to step S142.

[0048] The control unit 630 determines whether the comparison result of step S141 is within the normal range (step S142). When the control unit 630 determines that the comparison result is within the normal range (Yes in step S142), since the detected moment value is in a normal state, it ends the position control shown in FIG. 9 and returns to the process of step S140 shown in FIG. 6.

[0049] Also, when the control unit 630 determines that the comparison result is not within the normal range (No in step S142), the process proceeds to the process of step S143. The control unit 630 determines whether the comparison result in step S141 is higher than the normal range (step S143). When the control unit 630 determines that the comparison result is higher than the normal range (Yes in step S143), the process proceeds to step S144.

[0050] The control unit 630 performs control to raise the position of the welding wire 700 (step S144). For example, the control unit 630 changes the angle of the fixing unit 340 to the supply device 300 so as to raise the position of the tip 710 of the welding wire 700 in order to keep the moment value within the normal range. Specifically, the control unit 630 determines the position of the tip 710 of the welding wire 700 based on the difference between the moment value and the upper limit value of the normal range, and operates the supply device 300 so that the angle of the fixing unit 340 corresponding to the position is obtained. Thereby, the control device 600 can raise the position of the tip 710 of the welding wire 700 fed from the wire nozzle 330 upward. Then, when the process of step S144 is completed, the control unit 630 returns the process to step S141 which has been described above and continues the process.

[0051] Also, when the control unit 630 determines that the comparison result in step S141 is not higher than the normal range (No in step S143), the process proceeds to step S145. The control unit 630 performs control to lower the position of the welding wire 700 (step S145). For example, the control unit 630 changes the angle of the fixing unit 340 to the feeding device 300 so as to lower the position of the tip 710 of the welding wire 700 in order to keep the moment value within the normal range. Specifically, the control unit 630 determines the position of the tip 710 of the welding wire 700 based on the difference between the moment value and the lower limit value of the normal range, and operates the feeding device 300 so that the angle of the fixing unit 340 corresponds to the position. Thereby, the control device 600 can lower the position of the tip 710 of the welding wire 700 fed from the wire nozzle 330 downward. When the process of step S145 is completed, the control unit 630 returns the process to step S141 which has been described above and continues the process.

[0052] The control unit 630 executes the process of step S141 again. After that, when it is determined that the comparison result is not within the normal range (No in step S142), the subsequent processing procedure is continued. Also, when the control unit 630 determines that the comparison result is within the normal range (Yes in step S142), since the detected moment value has changed to a normal state, the position control process shown in FIG. 9 in the vertical direction 920 is terminated, and the process returns to the process of step S140 shown in FIG. 6.

[0053] Returning to FIG. 6, when the process of step S140 is completed, the control unit 630 proceeds the process to step S150. The control unit 630 executes control of the feeding speed of the welding wire 700 (step S150). The control unit 630 controls the feeding speed of the welding wire 700 based on the load value detected by the sensor 500. For example, the control unit 630 compares the load value of the sensor 500 with the normal range of the load value measured after welding stability by executing the feeding speed control process shown in FIG. 10 (step S151). For example, the control unit 630 compares whether the load value is within the normal range shown in FIG. 7 estimated in step S120, whether the value is larger or smaller than the normal range, and stores the information indicating the comparison result in the storage unit 620.

[0054] The control unit 630 determines whether the comparison result in step S151 is within the normal range (step S152). When the control unit 630 determines that the comparison result is within the normal range (Yes in step S152), since the detected load value is in a normal state, it ends the position control shown in FIG. 10 and returns to the process of step S150 shown in FIG. 6.

[0055] Also, when the control unit 630 determines that the comparison result is not within the normal range (No in step S152), it advances the process to the process of step S153. The control unit 630 determines whether the comparison result in step S151 is higher than the normal range (step S153). When the control unit 630 determines that the comparison result is higher than the normal range (Yes in step S153), it advances the process to step S154.

[0056] The control unit 630 performs control to decrease the feeding speed of the welding wire 700 (step S154). For example, the control unit 630 controls the operation of the supply device 300 so as to decrease the feeding speed of the welding wire 700 in order to keep the load value within the normal range. Specifically, the control unit 630 determines the feeding speed to be decreased for the welding wire 700 based on the difference between the load value and the upper limit value of the normal range, and changes the rotation speed of the wire reel unit 310 of the supply device 300 so as to achieve the feeding speed. Thereby, the control device 600 can decrease the speed of the welding wire 700 fed from the wire nozzle 330. Then, when the process of step S154 ends, the control unit 630 returns the process to step S151 which has been described above.

[0057] Also, when the control unit 630 determines that the comparison result in step S151 is not higher than the normal range (No in step S153), the process proceeds to step S155. The control unit 630 performs control to increase the feeding speed of the welding wire 700 (step S155). For example, the control unit 630 controls the operation of the supply device 300 so as to increase the feeding speed of the welding wire 700 in order to keep the load value within the normal range. Specifically, the control unit 630 determines the feeding speed to be increased for the welding wire 700 based on the difference between the load value and the lower limit value of the normal range, and changes the rotation speed of the wire reel unit 310 of the supply device 300 so as to achieve the feeding speed. Thereby, the control device 600 can increase the speed of the welding wire 700 fed from the wire nozzle 330. When the process of step S155 is completed, the control unit 630 returns the process to step S151 which has been described above.

[0058] The control unit 630 executes the process of step S151 again, and then, when it determines that the comparison result is not within the normal range (No in step S152), continues the subsequent processing procedure. Also, when the control unit 630 determines that the comparison result is within the normal range (Yes in step S152), since the detected load value has changed to a normal state, it ends the feeding speed control process shown in FIG. 10 and returns to the process of step S150 shown in FIG. 6. When the process of step S150 is completed, the control unit 630 ends the processing procedure shown in FIG. 6.

[0059] The processing procedure shown in FIG. 6 may omit the process of controlling the position in the left - right direction 910 of the welding wire - welding electrode in step S130.

[0060] (Operation example of the welding system) The welding system 10 shown in FIG. 1 will be described with respect to an example operation of welding. When starting welding, the control device 600 of the welding system 10 causes the imaging device 400 to capture the state of the welding torch 110 at the start-up of the welding device 100, and stores the captured image information in the storage unit 620. The control device 600 controls the supply device 300 to move inside the supply cable 320 and supply the welding wire 700 from the wire nozzle 330 toward the welding position 800. Based on the image information captured by the imaging device 400 of the welding position 800, the control device 600 confirms that the tip 710 of the welding wire 700 is positioned at the welding position 800, and drives the welding torch 110 of the welding device 100. Thereby, the welding torch 110 of the welding device 100 welds the welding wire 700 and the welding object 1000 by utilizing, for example, a discharge phenomenon in the air.

[0061] After welding starts and the welding becomes stable, the control device 600 detects the load value and the moment value by the force sensor of the sensor 500 over a certain period of time, and determines the normal range of the load value and the moment value in the normal state. Alternatively, the control device 600 obtains the normal range of the load value and the moment value determined by prior tests, simulations, etc. from the storage unit 620, a server device or a database outside the device, etc. The control device 600 utilizes deep learning for the image 410 (see FIG. 3) of the welding position 800 to perform position control in the left-right direction 910 of the welding wire 700 and the welding electrode 112. After the positions of the welding wire 700 and the welding electrode 112 in the left-right direction 910 reach normal values, the control device 600 performs position control in the up-down direction 920 of the welding wire 700 based on the moment value detected by the sensor 500.

[0062] Next, the control device 600 compares the moment value detected by the sensor 500 with the normal range of the first condition. As shown in FIG. 8, when the moment value is greater than the normal range of the first condition, the control device 600 adjusts the orientation of the fixing portion 340 of the supply device 300 so as to raise the position of the welding wire 700. Further, when the moment value is less than the normal range of the first condition, the control device 600 adjusts the orientation of the fixing portion 340 of the supply device 300 so as to lower the position of the welding wire 700. Then, the control device 600 adjusts the position of the welding wire 700 in the vertical direction 920 until the moment value falls within the normal range of the first condition. Note that when the moment value falls within the normal range of the first condition, the control device 600 does not execute the position control process of the welding wire 700 in the vertical direction 920.

[0063] Next, in a state where the moment value falls within the normal range of the first condition, the control device 600 compares the load value detected by the sensor 500 with the normal range of the second condition. As shown in FIG. 7, when the load value is greater than the normal range of the second condition, the control device 600 adjusts the drive of the wire reel portion 310 of the supply device 300 so as to decrease the feeding speed of the welding wire 700. Further, when the load value is less than the normal range of the second condition, the control device 600 adjusts the drive of the wire reel portion 310 of the supply device 300 so as to increase the feeding speed of the welding wire 700. Then, the control device 600 adjusts the feeding speed of the welding wire 700 until the load value falls within the normal range of the second condition. Note that when the load value falls within the normal range of the second condition, the control device 600 does not execute the feeding speed control process of the welding wire 700.

[0064] As described above, the control device 600 detects the moment value and load value of the welding wire 700 that feeds the feeding cable 320 and the wire nozzle 330 fixed to the fixing part 340 by the sensor 500, and can adjust the position of the tip 710 of the welding wire 700 in the vertical direction 920 and the feeding speed of the welding wire 700 from the moment value and the load value. Thereby, the control device 600 performs control according to the contact state of the welding wire 700 based on the moment value and the load value without detecting the load from the feeding cable 320 of the welding wire 700 as noise, so that the feeding state of the welding wire 700 and the position of the tip 710 in the vertical direction 920 can be stabilized.

[0065] (Other Embodiments) In the above-described embodiment, the processing procedure of the control method shown in FIG. 6 has been described for the case where the reference moment value and load value are set after the start of welding, but it is not limited thereto. The processing procedure of the control method may be a processing procedure for setting the reference moment value and load value before the start of welding. FIG. 11 is a flowchart showing another example of the processing procedure of the control method executed by the control device 600. FIG. 12 is a flowchart showing an example of the position control in the vertical direction 920 shown in FIG. 11. FIG. 13 is a flowchart showing an example of the feeding speed control shown in FIG. 11. The processing procedure shown in FIG. 11 deletes the processing of step S120 from the processing procedure shown in FIG. 6, and adds the processing of step S101 and step S102 as preprocessing of step S110. That is, the processing of step S110, step S130 to step S150 in the processing procedure shown in FIG. 11 is the same as the processing of step S110, step S130 to step S150 shown in FIG. 6.

[0066] As shown in FIG. 11, the control unit 630 of the control device 600 sets a reference load value and moment value (step S101). For example, the control unit 630 obtains the reference load value and moment value selected in advance through welding tests, simulations, etc. from the storage unit 620, the server device, the database, etc., and sets them as the reference load value and moment value. The control unit 630 sets a normal range of the load value based on the reference load value and a normal range of the moment value based on the reference moment value. The setting of the normal range can be performed based on, for example, a predetermined range from the reference value, a range obtained by inputting the reference value into a learning model, a range obtained from the reference value and a look-up table, etc. When the process of step S101 is completed, the control unit 630 advances the process to step S102.

[0067] The control unit 630 starts welding (step S102). For example, the control unit 630 controls the supply device 300 to start feeding the welding wire 70 and controls the welding device 100 to start welding. When the process of step S102 is completed, the control unit 630 advances the process to step S110 which has been described above.

[0068] The control unit 630 acquires sensor information including the load value and moment value after welding stabilization from the sensor 500 (step S110). After the control unit 630 stores the acquired sensor information in the storage unit 620 in chronological order, it advances the process to step S130. The control unit 630 controls the position of the welding wire and the welding electrode in the left - right direction 910 (step S130). When the process of step S130 is completed, the control unit 630 advances the process to step S140.

[0069] The control unit 630 executes position control of the welding wire 700 in the up - down direction 920 (step S140). In other embodiments, the control unit 630 controls the position of the tip 710 of the welding wire 700 in the up - down direction 920 according to the moment value detected by the sensor 500 based on the reference moment value and the normal range set before the start of welding.

[0070] For example, the control unit 630 executes the position control process shown in FIG. 12 in the vertical direction 920, and compares the moment value of the sensor 500 with the normal range of the reference moment value set until the start of welding (step S141-1). For example, the control unit 630 compares whether the moment value is within the normal range shown in FIG. 8 estimated in step S120, whether the value is larger or smaller than the normal range, and stores the information indicating the comparison result in the storage unit 620. When the process of step S141-1 is completed, the control unit 630 proceeds to step S142. Then, the control unit 630 executes the processes after step S142. Since the processes from step S142 to step S145 shown in FIG. 12 are the same as the processes from step S142 to step S145 shown in FIG. 9, the description thereof is omitted.

[0071] When the control unit 630 determines that it is within the normal range in step S142 (Yes in step S142), since the detected moment value has changed to a normal state, the position control process shown in FIG. 12 in the vertical direction 920 is terminated, and the process returns to step S140 shown in FIG. 11.

[0072] Returning to FIG. 11, when the process of step S140 is completed, the control unit 630 proceeds to step S150. The control unit 630 executes the feeding speed control of the welding wire 700 (step S150). The control unit 630 controls the feeding speed of the welding wire 700 according to the load value detected by the sensor 500. For example, the control unit 630 executes the feeding speed control process shown in FIG. 13, and compares the load value of the sensor 500 with the normal range of the reference load value set until the start of welding (step S151-1). For example, the control unit 630 compares whether the load value is within the normal range shown in FIG. 7 estimated in step S120, whether the value is larger or smaller than the normal range, and stores the information indicating the comparison result in the storage unit 620.

[0073] When the process of step S151-1 ends, the control unit 630 advances the process to step S152. Then, the control unit 630 executes the processes after step S152. Since the processes from step S152 to step S155 shown in FIG. 13 are the same as those from step S152 to step S155 shown in FIG. 10, the description thereof is omitted.

[0074] When the control unit 630 determines that the comparison result is within the normal range in step S152 (Yes in step S152), since the detected load value has changed to a normal state, the feeding speed control process shown in FIG. 13 is terminated, and the process returns to the process of step S150 shown in FIG. 11. When the process of step S150 ends, the control unit 630 ends the process procedure shown in FIG. 11.

[0075] By executing the process procedure shown in FIG. 11, the control device 600 can, similar to the present embodiment, stabilize the feeding state of the welding wire 700 and the position in the vertical direction 920 of the tip portion 710, and can simplify the process and increase the processing speed compared to executing the process procedure shown in FIG. 6.

[0076] In the above-described present embodiment, the position control shown in FIG. 9 in the vertical direction 920 and the feeding speed control shown in FIG. 10 may be used as a control method modified to include a process of setting a reference moment value or load value and its normal range in advance until welding starts, similar to the process procedure shown in FIG. 11. For example, the process procedure of the position control may be a control method in which a reference moment value and a normal range are set until welding starts, welding is started, and then the detected moment value is compared with the normal range to control the position of the welding wire 700. For example, the process procedure of the feeding speed control may be a control method in which a reference load value and a normal range are set until welding starts, welding is started, and then the detected load value is compared with the normal range to control the feeding speed of the welding wire 700.

[0077] In the above-described embodiment, the control device 600 has been described for the case where it estimates the normal ranges of the moment value and the load value detected by the sensor 500 and sets these normal ranges as the first condition for the moment value and the second condition for the load value, but it is not limited thereto. For example, the control device 600 may set the first condition and the second condition as the abnormal ranges of the respective values, or may set the upper limit value, the lower limit value, or one of them.

[0078] In the above-described embodiment, the control device 600 has been described for the case where it is an independent device of the welding system 10, but it is not limited thereto. For example, the control device 600 may be configured to be incorporated into the welding device 100, the supply device 300, etc. of the welding system 10. That is, the control method may be executed by a CPU (computer) of the welding device 100, the supply device 300, etc. of the welding system 10.

[0079] (Effect) The control device 600 is a control device 600 that controls the welding wire 700 to move inside the feeding cable 320 and feeds the welding wire 700 from the wire nozzle 330 fixed to the fixing portion 340 toward the welding position 800. The control device 600 includes an acquisition unit 631 that acquires sensor information including the load value and the moment value generated in the welding wire 700 fed from the wire nozzle 330 from the sensor 500, and a wire control unit 632 that controls the position and the feeding speed of the tip portion 710 of the welding wire 700 in the vertical direction based on the load value and the moment value. Thereby, the control device 600 performs control according to the contact state of the welding wire 700 based on the moment value and the load value without detecting the load from the feeding cable 320 of the welding wire 700 as noise, so that the feeding state of the welding wire 700 and the position of the tip portion 710 in the vertical direction 920 can be stabilized. As a result, the control device 600 can reduce the occurrence probability of welding defects in the welding system 10, and thus can contribute to the automation of TIG welding. Furthermore, the control device 600 can contribute to the realization of the de-skilling and labor saving of the operator who monitors the welding of the welding system 10.

[0080] In the control device 600, the wire control unit 632 compares the moment value of the sensor information with the first condition, and adjusts the position of the tip 710 of the welding wire 700 in the vertical direction based on the comparison result. Thereby, since the control device 600 can adjust the position of the welding wire 700 from the comparison result between the first condition set to suit the feeding environment and the actually detected moment value, it is possible to further stabilize the position of the tip 710 of the welding wire 700 in the vertical direction 920.

[0081] In the control device 600, the first condition includes the normal range of the moment value. When the moment value is higher than the normal range, the wire control unit 632 controls the feeding device 300 to raise the position of the tip 710 of the welding wire 700. When the moment value is lower than the normal range, the wire control unit 632 controls the feeding device 300 to lower the position of the tip 710 of the welding wire 700. Thereby, since the control device 600 can adjust the position of the welding wire 700 only based on the detected moment value, it is possible to further stabilize the position of the tip 710 of the welding wire 700 in the vertical direction 920 without complicating the configuration of the welding system 10.

[0082] In the control device 600, the wire control unit 632 estimates the normal range of the moment value based on the sensor information acquired from the sensor 500 after the welding location has stabilized after starting the welding. Thereby, since the control device 600 can set the normal range of the moment value suitable for the feeding path of the welding wire 700, it is possible to further stabilize the position of the tip 710 of the welding wire 700 in the vertical direction 920 by the control based on the normal range.

[0083] In the control device 600, the wire control unit 632 compares the load value of the sensor information with the second condition, and adjusts the feeding speed of the welding wire 700 based on the comparison result. Thereby, since the control device 600 can adjust the feeding speed of the welding wire 700 from the comparison result between the second condition set to suit the feeding environment and the actually detected load value, it is possible to further stabilize the feeding state of the welding wire 700.

[0084] In the control device 600, the second condition includes the normal range of the load value. When the load value is higher than the normal range, the wire control unit 632 controls the supply device 300 to decrease the feeding speed of the welding wire 700. When the load value is lower than the normal range, the wire control unit 632 controls the supply device 300 to increase the feeding speed of the welding wire 700. Thereby, the control device 600 can adjust the feeding speed of the welding wire 700 only based on the detected load value, so that the feeding state of the welding wire 700 can be further stabilized without complicating the configuration of the welding system 10.

[0085] In the control device 600, the wire control unit 632 estimates the normal range of the load value based on the sensor information acquired from the sensor 500 after the welding location has stabilized after starting welding. Thereby, the control device 600 can set the normal range of the load value suitable for the feeding path of the welding wire 700, so that the feeding state of the welding wire 700 can be further stabilized by the control based on the normal range.

[0086] In the control device 600, the wire control unit 632 adjusts the position in the left - right direction 910 between the welding wire 700 and the welding electrode 112 based on the image information obtained by imaging the welding position. Thereby, after the control device 600 adjusts the left - right direction 910 between the welding wire 700 and the welding electrode 112 to a normal position, it can perform control according to the contact state of the welding wire 700 based on the moment value and the load value, so that the probability of occurrence of welding defects using the welding wire 700 can be further reduced.

[0087] The welding system 10 includes a welding device 100 that melts and welds a welding wire 700, a feeding cable 320 that feeds the welding wire 700, a wire nozzle 330 that communicates with the feeding cable 320, and a fixing portion 340 that is provided between the feeding cable 320 and the wire nozzle 330 and is fixed to another member. The welding system 10 further includes a feeding device 300 that feeds the welding wire 700 from the wire nozzle fixed to the fixing portion 340 toward the welding position, a sensor 500 that detects sensor information including the load value and moment value of the tip portion 710 of the welding wire 700, and a control device 600 that controls the feeding of the welding wire 700 from the wire nozzle 330 toward the welding position 800. The control device 600 includes an acquisition unit 631 that acquires sensor information including the load value and moment value generated in the welding wire 700 fed from the wire nozzle 330 from the sensor 500, and a wire control unit 632 that controls the position and feeding speed of the tip portion 710 of the welding wire 700 in the vertical direction based on the load value and moment value. As a result, the welding system 10 can perform control according to the contact state of the welding wire 700 based on the moment value and load value without the control device 600 detecting the load from the feeding cable 320 of the welding wire 700 as noise, so that the feeding state of the welding wire 700 and the stabilization of the position of the tip portion 710 in the vertical direction 920 can be achieved. Consequently, the welding system 10 can reduce the occurrence probability of welding defects in the system, and thus can contribute to the automation of TIG welding. Further, the welding system 10 can contribute to the realization of the de-skilling and labor reduction of the operator who monitors the welding in the system.

[0088] The control method is a control method executed by a control device 600 that controls the movement of a welding wire 700 inside a feeding cable 320 and feeds the welding wire 700 from a wire nozzle 330 fixed to a fixing portion 340 toward a welding position 800. The control method includes an acquisition step of acquiring sensor information including a load value and a moment value generated in the welding wire 700 fed from the wire nozzle 330 from a sensor 500, and a wire control step of controlling the position and the feeding speed of the tip portion 710 of the welding wire 700 in the vertical direction 920 based on the load value and the moment value. Thereby, the control method enables the control device 600 to perform control according to the contact state of the welding wire 700 based on the moment value and the load value without detecting the load from the feeding cable 320 of the welding wire 700 as noise, so that the feeding state of the welding wire 700 and the stabilization of the position of the tip portion 710 in the vertical direction 920 can be achieved. As a result, since the control method can reduce the occurrence probability of welding defects in the welding system 10, it can contribute to the automation of TIG welding. Further, the control method can contribute to the realization of the deskilling and labor saving of the operator who monitors the welding of the welding system 10.

[0089] As described above, the embodiments of the present disclosure have been described. However, the embodiments are not limited by the contents of these embodiments. Further, the above-described components include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those within a so-called equivalent range. Furthermore, the above-described components can be combined as appropriate. Furthermore, various omissions, substitutions, or changes of the components can be made without departing from the gist of the above-described embodiments.

Explanation of Reference Numerals

[0090] 10 Welding system 100 Welding apparatus 110 Welding torch 111 Welding head 112 Welding electrode 200 Support device 210 Frame 300 Feeding device 310 Wire reel portion 320 Feed cable 330 Wire nozzle 340 Fixing part 341 Through-hole 400 Imaging device 500 Sensor 600 Control device 610 Communication unit 620 Memory unit 630 Control unit 631 Acquisition unit 632 Wire control unit 700 Welding wire 800 Welding position 910 Left - right direction 920 Up - down direction

Claims

1. A control device that moves a welding wire inside a feeding cable and controls the feeding of the welding wire from a wire nozzle fixed to a fixing part toward a welding position, comprising: an acquisition unit that acquires sensor information including a load value and a moment value generated in the welding wire fed from the wire nozzle from a sensor; a wire control unit that controls the position and feeding speed of the tip of the welding wire in the vertical direction based on the load value and the moment value; The control device is provided with.

2. The control device according to claim 1, wherein the wire control unit compares the moment value of the sensor information with a first condition and adjusts the position of the tip of the welding wire in the vertical direction based on the comparison result.

3. The first condition includes a normal range of the moment value, When the moment value is higher than the normal range, the wire control unit controls the feeding device to raise the position of the tip of the welding wire, and when the moment value is lower than the normal range, the wire control unit controls the feeding device to lower the position of the tip of the welding wire. The control device according to claim 2.

4. The control device according to claim 3, wherein the wire control unit estimates the normal range of the moment value based on the sensor information acquired from the sensor after the welding location has stabilized after starting welding.

5. The control device according to any one of claims 1 to 4, wherein the wire control unit compares the load value of the sensor information with a second condition and adjusts the feeding speed of the welding wire based on the comparison result.

6. The second condition includes a normal range of the load value, When the load value is higher than the normal range, the wire control unit controls the feeding device to decrease the feeding speed of the welding wire, and when the load value is lower than the normal range, the wire control unit controls the feeding device to increase the feeding speed of the welding wire. The control device according to claim 5.

7. The control device according to claim 6, wherein the wire control unit estimates the normal range of the load value based on the sensor information acquired from the sensor after the welding location has stabilized after starting welding.

8. The control device according to claim 7, wherein the wire control unit adjusts the position of the welding wire and the welding electrode in the left - right direction based on image information obtained by imaging the welding position.

9. A welding apparatus that melts and welds a welding wire, a feeding cable that feeds the welding wire, a wire nozzle that communicates with the feeding cable, and a supply device that is provided between the feeding cable and the wire nozzle and has a fixing portion fixed to another member, and feeds the welding wire from the wire nozzle fixed to the fixing portion toward a welding position, a sensor that detects sensor information including a load value and a moment value at the tip of the welding wire, a control device that controls the feeding of the welding wire from the wire nozzle toward the welding position, comprising, the control device, an acquisition unit that acquires, from the sensor, sensor information including a load value and a moment value generated in the welding wire fed from the wire nozzle, a wire control unit that controls the position and feeding speed of the tip of the welding wire in the vertical direction based on the load value and the moment value, A welding system comprising.

10. A control method executed by a control device that moves a welding wire inside a feeding cable and controls the feeding of the welding wire from a wire nozzle fixed to a fixing portion toward a welding position, an acquisition step of acquiring, from a sensor, sensor information including a load value and a moment value generated in the welding wire fed from the wire nozzle, a wire control step of controlling the position and feeding speed of the tip of the welding wire in the vertical direction based on the load value and the moment value, A control method including.

Images