CONTROL DEVICE, WELDING SYSTEM AND PROGRAM

Abstract

Provided are a control device, a welding system and a program which can improve welding quality as compared to the prior art.　A control device according to an embodiment comprises: an input / output unit; a measurement unit; and a processing unit. The input / output unit outputs first information for instructing an arc welding machine to start welding, and receives input of second information indicating that an arc has been generated by the arc welding machine. The measurement unit measures the time from the output of the first information until the input of the second information. The processing unit performs prescribed processing if the time or a statistical quantity of the time falls below a first threshold value.

Description

[Technical field]

[0001] The present invention relates to a control device, a welding system, and a program. [Background technology]

[0002] When an arc welding machine starts welding while the wire is in contact with the workpiece (hereinafter, "starting welding while the wire is in contact with the workpiece" is referred to as a "touch start"), poor starts and tip adhesion are likely to occur, which are known to be factors that reduce welding quality. As a workaround for this, a method is known in which, if a touch start is determined, the wire is run in reverse at the end of welding of the previous welding point to avoid a touch start (Patent Document 1). However, with this method, even if the desired tip-to-workpiece distance cannot be obtained, welding continues as is, and it cannot be said that a reduction in welding quality is avoided. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4428073 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for a control device that can improve welding quality compared to the conventional technology. [Means for solving the problem]

[0005] The control device of the present disclosure includes an input / output unit, a measurement unit, and a processing unit. The input / output unit outputs first information instructing an arc welder to start welding, and receives input of second information indicating generation of an arc by the arc welder. The measurement unit measures the time from output of the first information to input of the second information. The processing unit: Measured multiple times The time Of which, It is equal to or less than the first threshold The number or percentage of times is equal to or greater than a second threshold. If so, a predetermined process is carried out. Effect of the Invention

[0006] The control device of the present disclosure can improve welding quality compared to conventional methods. [Brief description of the drawings]

[0007] [Figure 1] 1 is a block diagram showing an example of a main configuration of a welding system according to an embodiment and components included in the welding system; [Diagram 2] 2 is a flowchart showing an example of processing by a processor of the robot control device in FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, a welding system according to an embodiment will be described with reference to the drawings. Note that the scale of each part in each drawing used in the following description of the embodiment may be changed as appropriate. Also, for the sake of explanation, each drawing used in the following description of the embodiment may be shown with the configuration omitted. Also, in each drawing and in this specification, the same reference numerals indicate similar elements. 1 is a block diagram showing an example of a welding system 1 according to an embodiment and a main configuration of components included in the welding system 1. The welding system 1 is a system that performs arc welding using a robot arm. The welding system 1 includes, as an example, a robot control device 100, a welding robot 200, an arc welder 300, and a teaching device 400.

[0009] The robot control device 100 is a device that controls the welding robot 200. The robot control device 100 includes, for example, a processor 110, a read-only memory (ROM) 120, a random-access memory (RAM) 130, an auxiliary storage device 140, a communication interface 150, a control interface 160, and a welding interface 170. A bus 180 and the like connect these respective units.

[0010] The processor 110 is a central part of a computer that performs various calculations and processes such as calculations and control required for the operation of the robot control device 100. The processor 110 is, for example, a central processing unit (CPU), a micro processing unit (MPU), a system on a chip (SoC), a digital signal processor (DSP), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field-programmable gate array (FPGA). Alternatively, the processor 110 is a combination of a plurality of these. The processor 110 may also be a combination of these with a hardware accelerator or the like. The processor 110 controls each part to realize various functions of the robot control device 100 based on programs such as firmware, system software, and application software stored in the ROM 120 or the auxiliary storage device 140. The processor 110 also executes processes described below based on the programs. Note that a part or all of the programs may be incorporated in the circuitry of the processor 110.

[0011] The ROM 120 and the RAM 130 are main memory devices of the computer with the processor 110 at its core. The ROM 120 is a non-volatile memory used exclusively for reading data. The ROM 120 stores, for example, firmware among the above programs. The ROM 120 also stores data used by the processor 110 when performing various processes. The RAM 130 is a memory used for reading and writing data. The RAM 130 is used as a work area for storing data that is temporarily used when the processor 110 performs various processes. The RAM 130 is typically a volatile memory.

[0012] The auxiliary storage device 140 is an auxiliary storage device of a computer with the processor 110 at its core. The auxiliary storage device 140 is, for example, an EEPROM (electric erasable programmable read-only memory), a HDD (hard disk drive), or a flash memory. The auxiliary storage device 140 stores, for example, system software and application software among the above programs. The auxiliary storage device 140 also stores data used by the processor 110 in performing various processes, data generated by the processes in the processor 110, various setting values, and the like.

[0013] Further, the auxiliary storage device 140 stores a program (hereinafter referred to as a "robot program") for operating the welding robot 200. The robot program determines the start position of arc welding, the operation of the driving unit 210, and the like.

[0014] The auxiliary storage device 140 also stores settings (hereinafter referred to as "operation settings") related to the operation of the robot control device 100. The operation settings include, for example, a setting indicating whether or not to execute a notification process, a setting indicating whether or not to execute a correction process, and a setting indicating the values ​​of each threshold and the value of the distance D1. The notification process, the correction process, each threshold, and the distance D1 will be described later.

[0015] The communication interface 150 is an interface for the robot control device 100 to communicate with the teaching device 400 and other devices. The communication may be wired or wireless.

[0016] The control interface 160 is an interface through which the robot controller 100 communicates with the welding robot 200. The communication may be wired or wireless. The robot controller 100 controls the welding robot 200 via the control interface 160.

[0017] Welding interface 170 is an interface for robot controller 100 to communicate with arc welder 300. The communication may be wired or wireless. Robot controller 100 controls arc welder 300 via welding interface 170.

[0018] The bus 180 includes a control bus, an address bus, a data bus, etc., and transmits signals exchanged among the various parts of the robot control device 100 .

[0019] Welding robot 200 is a device such as a robot that performs arc welding on an object to be welded OB. Welding robot 200 changes the relative positions of welding torch 230 and object to be welded OB by moving at least one of welding torch 230 and object to be welded OB using, for example, a robot arm. In this way, welding robot 200 performs welding on a desired position of object to be welded OB. Welding robot 200 includes, for example, a drive unit 210, a wire feeder 220, and a welding torch 230. Note that welding robot 200 may have some or all of the functions of arc welder 300.

[0020] The driving unit 210 is a part that is driven by a motor such as a servo motor, etc. The driving unit 210 includes, for example, a robot arm.

[0021] The wire feeder 220 feeds a welding wire from a wire supply source to the welding torch 230. The wire feeder 220 also controls the opening and closing of an electromagnetic valve disposed in a supply path of an assist gas from an assist gas supply source to the welding torch 230.

[0022] Welding torch 230 is a tool at the tip provided for performing arc welding. In welding torch 230, a welding wire is fed into a cylinder by wire feeder 220. Welding torch 230 supplies power supplied from arc welder 300 to the welding wire. Welding torch 230 also includes, for example, a mechanism for ejecting shielding gas.

[0023] Arc welder 300 functions as a power source that supplies the power required for arc welding to welding torch 230 and the like. Arc welder 300 also has a function of receiving a signal that detects the flow of electricity to a workpiece and notifying other devices of the signal. Arc welder 300 may also have some of the functions of welding robot 200.

[0024] The teaching device 400 is a device for creating a robot program. The robot program may be created by any of online teaching, offline teaching, direct teaching, or other program creation methods. The teaching device 400 is, for example, a teaching pendant capable of performing online teaching. The teaching device 400 is, for example, a device such as a PC (personal computer) that executes software for offline teaching. The robot control device 100 may have some or all of the functions of the teaching device 400. Also, the welding robot 200 may have some or all of the functions of the teaching device 400.

[0025] The teaching device 400 includes, for example, a processor 410, a ROM 420, a RAM 430, an auxiliary storage device 440, a communication interface 450, an input device 460, and a display device 470. A bus 480 or the like connects these components together.

[0026] The processor 410 is a central part of a computer that performs various calculations and processes such as calculations and control required for the operation of the teaching device 400. The processor 410 is, for example, a CPU, an MPU, an SoC, a DSP, a GPU, an ASIC, a PLD, or an FPGA. Alternatively, the processor 410 is a combination of a plurality of these. The processor 410 may also be a combination of these with a hardware accelerator. The processor 410 controls each part to realize various functions of the teaching device 400 based on programs such as firmware, system software, and application software stored in the ROM 420 or the auxiliary storage device 440. The processor 410 also executes processes described below based on the programs. Note that a part or all of the programs may be incorporated in the circuitry of the processor 410.

[0027] The ROM 420 and the RAM 430 are the main memory devices of the computer centered around the processor 410 . The ROM 420 is a non-volatile memory used exclusively for reading data. The ROM 420 stores, for example, firmware among the above programs. The ROM 420 also stores data used by the processor 410 when performing various processes. The RAM 430 is a memory used for reading and writing data. The RAM 430 is used as a work area for storing data that is temporarily used when the processor 410 performs various processes. The RAM 430 is typically a volatile memory.

[0028] The auxiliary storage device 440 is an auxiliary storage device of a computer with the processor 410 as its core. The auxiliary storage device 440 is, for example, an EEPROM, a HDD, or a flash memory. The auxiliary storage device 440 stores, for example, system software and application software among the above programs. The auxiliary storage device 440 also stores data used by the processor 410 in performing various processes, data generated by the processes in the processor 410, various setting values, and the like.

[0029] The communication interface 450 is an interface for the teaching device 400 to communicate with the robot control device 100 and the like. The communication may be wired or wireless.

[0030] The input device 460 accepts operations by an operator of the teaching apparatus 400. The input device 460 is, for example, a keyboard, a keypad, a touchpad, a mouse, a controller, etc. The input device 460 may also be a device for voice input.

[0031] The display device 470 displays a screen for notifying the operator of the teaching device 400 of various information. The display device 470 is, for example, a display such as a liquid crystal display or an organic EL (electro-luminescence) display. A touch panel can also be used as the input device 460 and the display device 470. That is, a display panel included in the touch panel can be used as the display device 470, and a touch pad included in the touch panel can be used as the input device 460.

[0032] The bus 480 includes a control bus, an address bus, a data bus, etc., and transmits signals exchanged among the various parts of the teaching device 400 .

[0033] The operation of the welding system 1 according to the embodiment will be described below with reference to FIG. 2 and other figures. Note that the contents of the process in the following operation description are merely examples, and various processes capable of obtaining similar results can be used as appropriate. FIG. 2 is a flowchart showing an example of a process by the processor 110 of the robot control device 100. The processor 110 executes the process of FIG. 2 based on a program stored in, for example, the ROM 120 or the auxiliary storage device 140. The processor 110 starts the process shown in FIG. 2, for example, when the robot control device 100 is started up.

[0034] In step ST11, processor 110 determines whether or not to change the operation settings. For example, processor 110 determines to change the operation settings when there is an input instructing to change the operation settings. The input is based on, for example, an operation input by an operator of teaching device 400. The input is input, for example, via communication interface 150. If processor 110 does not determine to change the operation settings, it determines No in step ST11, and the process proceeds to step ST12.

[0035] In step ST12, the processor 110 determines whether or not to add a new robot program. For example, the processor 110 determines to add a robot program when there is an input instructing to add a robot program. The input is based on, for example, an operation input by an operator of the teaching device 400. The input is input, for example, via the communication interface 150. If the processor 110 does not determine to add a robot program, the processor 110 determines No in step ST12, and the process proceeds to step ST13.

[0036] In step ST13, processor 110 determines whether or not to start welding. For example, processor 110 determines to start operational welding when there is an input instructing to start welding. The input is based on, for example, an operation input by an operator of teaching device 400. The input is input, for example, via communication interface 150. If processor 110 does not determine to start welding, it determines No in step ST13, and the process proceeds to step ST14.

[0037] In step ST14, the processor 110 determines whether or not to change the stored robot program. For example, the processor 110 determines to start the operation welding when there is an input instructing to change the robot program. The input is based on, for example, an operation input by an operator of the teaching device 400. The input is input, for example, via the communication interface 150. If the processor 110 does not determine to change the robot program, the processor 110 determines No in step ST14, and the process returns to step ST11. Thus, the processor 110 enters a standby state in which steps ST11 to ST14 are repeated until it is determined to change the settings, add a robot program, start welding, or change the stored robot program.

[0038] If processor 110 determines that the setting is to be changed during the standby state of steps ST11 to ST14, the result in step ST11 is Yes, and the process proceeds to step ST15. In step ST15, the processor 110 changes the operation settings based on an input instructing the change content of the operation settings. The input is based on, for example, an operation input by an operator of the teaching device 400. The input is input, for example, via the communication interface 150. The processor 110 rewrites the operation settings stored in the auxiliary storage device 140, for example, to change the operation settings. After the processing of step ST15, the processing returns to step ST11.

[0039] If the processor 110 determines that a new robot program is to be added during the standby state of steps ST11 to ST14, the result of the determination in step ST12 is Yes, and the process proceeds to step ST16. In step ST16, the processor 110 stores the robot program created by various program creation methods using the teaching device 400 in the auxiliary storage device 140. The processor 110 stores the robot program in association with a program ID. A program ID (identifier) ​​is identification information unique to each robot program. After processing in step ST16, the process returns to step ST11.

[0040] If processor 110 determines to start welding during the standby state of steps ST11 to ST14, the result of step ST13 is Yes, and the process proceeds to step ST17. In step ST17, the processor 110 starts executing one of the robot programs stored in the auxiliary storage device 140. The robot program that starts to be executed here is hereinafter referred to as the "execution program." The processor 110 controls the welding robot 200 and the arc welder 300 based on the execution program. The processor 110 determines which robot program to execute based on, for example, an input that selects the robot program to be executed. The input is based on, for example, an operation input by the operator of the teaching device 400. The input is input via the communication interface 150, for example.

[0041] In step ST18, processor 110 moves welding torch 230 to a start position for arc welding based on the execution program.

[0042] In step ST19, processor 110 outputs a welding start command from welding interface 170, which indicates the start of welding. The output welding start command is input to arc welder 300. Arc welder 300 outputs the welding start command in response to receiving the input of the welding start command. An arc is generated between welding torch 230 and workpiece OB. When an arc is generated, arc welder 300 outputs a generation notification indicating that an arc has been generated. The generation notification is input from arc welder 300 to welding interface 170 of robot control device 100. Processor 110 stores time T1 at which the welding start command is output in RAM 130 or the like so that the elapsed time from the output of the welding start command can be known.

[0043] The welding start command is an example of first information instructing the start of welding. Moreover, the occurrence notification is an example of second information indicating the occurrence of an arc by arc welder 300. Thus, welding interface 170 is an example of an input / output unit. Moreover, processor 110 that controls welding interface 170 is an example of an input / output control unit. Arc welder 300 also functions as an example of a generating section by generating an arc in response to receiving a welding start command. Arc welder 300 also functions as an example of an output section by outputting a generation notification indicating that an arc has been generated when an arc has been generated.

[0044] In step ST20, processor 110 measures time ΔT from the output of the welding start command to the input of the occurrence notification. Processor 110 stores, for example, time T2 when the occurrence notification is input to welding interface 170 in RAM 130 or the like. Then, processor 110 obtains time ΔT by subtracting time T1 from time T2. Time ΔT is an example of a time from output of a welding start command to input of an occurrence notification. Therefore, processor 110 functions as an example of a measurement unit that measures the time by performing the process of step ST20.

[0045] In step ST21, the processor 110 stores the measurement result of the time ΔT in the auxiliary storage device 140 in association with the program ID of the execution program (hereinafter referred to as the "execution ID").

[0046] In step ST22, processor 110 determines whether or not to execute notification processing. Notification processing is processing for notifying an operator of teaching device 400 or the like that there is a possibility of a touch start occurring. Processor 110 determines to execute notification processing when, for example, time ΔT associated with the execution ID and stored in the auxiliary storage device satisfies a predetermined condition (hereinafter referred to as a "warning condition") and the operation setting is set to execute notification processing. Examples of warning conditions are shown below as (A1) to (A7). (A1) Of the times ΔT associated with the execution ID, the number of times ΔT that are equal to or less than a threshold TH11 is equal to or greater than a threshold TH12. Note that the value of the threshold TH12 may be 1. (A2) The ratio of the number of times ΔT that are equal to or less than the threshold TH11 to the number of times ΔT associated with the execution ID is equal to or greater than a threshold TH13. (A3) The average value of the time ΔT associated with the execution ID is less than or equal to a threshold value TH14. (A4) The median of the time ΔT associated with the execution ID is equal to or less than the threshold TH15. (A5) The minimum value of the time ΔT associated with the execution ID is equal to or less than the threshold value TH16. (A6) The maximum value of the time ΔT associated with the execution ID is equal to or less than the threshold value TH17. (A7) The latest time ΔT among the times ΔT associated with the execution ID is equal to or less than the threshold value TH18.

[0047] The warning condition may be a combination of the conditions (A1) to (A7).The warning condition may also be a condition using a statistic other than the average, median, minimum, and maximum.

[0048] The processor 110 may extract only a predetermined number of times ΔT associated with the execution IDs in ascending order of time from the most recent to determine whether the warning condition is satisfied. However, when the number of times ΔT associated with the execution IDs does not reach a predetermined number, the processor 110 may, for example, use all of the times ΔT associated with the execution IDs to determine whether the warning condition is satisfied. The processor 110 may extract only times ΔT measured within a predetermined period from the current time to determine whether the warning condition is satisfied. The processor 110 may also determine whether the warning condition is satisfied by excluding outliers. The processor 110 may use, for example, a known method as a method for excluding outliers. The processor 110 may also determine whether the warning condition is satisfied only when the number of times ΔT associated with the execution IDs is equal to or greater than a threshold value TH19.

[0049] Each of the thresholds TH11 and TH14 to TH18 is an example of a first threshold, and each of the thresholds TH12 and TH13 is an example of a second threshold.

[0050] If processor 110 determines to execute the notification process, the result in step ST22 is Yes, and the process proceeds to step ST23.

[0051] In step ST23, the processor 110 executes a notification process. As the notification process, the processor 110 instructs the teaching device 400 to display a warning screen on the display device 470, for example.

[0052] In response to the instruction, the processor 410 of the teaching device 400 generates an image corresponding to the warning screen. Then, the processor 410 instructs the display device 470 to display the generated image. In response to the display instruction, the display device 470 displays the warning screen.

[0053] The warning screen includes, for example, an image indicating that a touch start may have occurred, that a state is in which a touch start is likely to occur, or that a touch start may occur. Note that text is also a type of image. The warning screen also includes, for example, an image urging the user to correct the teaching position, such as by moving the welding torch 230 away from the welding object OB. The warning screen also includes an image indicating an execution ID so that the user can know which robot programming is the target of the notification process.

[0054] Furthermore, as the notification process, the processor 110 may output a sound having the same content as the content included in the warning screen from a speaker or the like provided in the teaching device 400. Furthermore, the processor 110 may notify the same content as the content included in the warning screen by other methods.

[0055] The warning process is an example of a predetermined process. Therefore, by performing the processes of steps ST22 and ST23, the processor 110 functions as an example of a processing unit that performs a predetermined process when the time is equal to or less than the first threshold value.

[0056] After the process of step ST23, the process proceeds to step ST24. If processor 110 determines not to execute the notification process, the result in step ST22 is No, and the process proceeds to step ST24.

[0057] In step ST24, processor 110 controls welding robot 200 based on the execution program to perform arc welding on the workpieces.

[0058] In step ST25, processor 110 determines whether or not to execute correction processing. Correction processing is processing for correcting the teaching position of the execution program to prevent the occurrence of a touch start. Processor 110 determines to execute correction processing, for example, when time ΔT associated with the execution ID and stored in the auxiliary storage device satisfies a predetermined condition (hereinafter referred to as a "correction condition") and the operation setting is set to execute correction processing. Examples of correction conditions are shown below as (B1) to (B7). (B1) Of the times ΔT associated with the execution ID, the number of times ΔT that are equal to or less than the threshold TH21 is equal to or greater than a threshold TH22. Note that the value of the threshold TH22 may be 1. (B2) The ratio of the number of times ΔT that are equal to or less than the threshold TH21 to the number of times ΔT associated with the execution ID is equal to or greater than a threshold TH23. (B3) The average value of the time ΔT associated with the execution ID is equal to or less than the threshold TH24. (B4) The median of the time ΔT associated with the execution ID is equal to or less than the threshold TH25. (B5) The minimum value of the time ΔT associated with the execution ID is equal to or less than the threshold value TH26. (B6) The maximum value of the time ΔT associated with the execution ID is equal to or less than the threshold TH27. (B7) The latest time ΔT among the times ΔT associated with the execution ID is equal to or less than the threshold value TH28.

[0059] The correction condition may be a combination of the conditions (B1) to (B7). The correction condition may also be a condition using a statistic other than the average, median, minimum, and maximum. The warning condition and the correction condition may be the same condition.

[0060] The processor 110 may extract only a predetermined number of times ΔT associated with the execution IDs in order from the most recent to determine whether the correction condition is satisfied. However, when the number of times ΔT associated with the execution IDs does not reach a predetermined number, the processor 110 may, for example, use all of the times ΔT associated with the execution IDs to determine whether the correction condition is satisfied. The processor 110 may extract only times ΔT measured within a predetermined period from the current time to determine whether the correction condition is satisfied. The processor 110 may also determine whether the correction condition is satisfied by excluding outliers. The processor 110 may use, for example, a known method as a method for excluding outliers. The processor 110 may also determine whether the correction condition is satisfied only when the number of times ΔT associated with the execution IDs is equal to or greater than a threshold value TH29.

[0061] Each of the thresholds TH21 and TH24 to TH28 is an example of a first threshold, and each of the thresholds TH22 and TH23 is an example of a second threshold.

[0062] If processor 110 determines not to execute the correction process, it determines No in step ST25, and the process returns to step ST11. On the other hand, if processor 110 determines to execute the correction process, it determines Yes in step ST25, and the process proceeds to step ST26.

[0063] In step ST26, processor 110 executes a correction process. For example, processor 110 rewrites the execution program stored in auxiliary storage device 140 to move the start position of arc welding in the corrected program away from the work-piece OB by a predetermined distance D1.

[0064] The correction process is an example of a predetermined process. Therefore, by performing the processes of steps ST25 and ST26, the processor 110 functions as an example of a processing unit that performs a predetermined process when the time is equal to or less than the first threshold value.

[0065] In step ST27, the processor 110 performs a reset process on the execution program. That is, the processor 110 prevents the time ΔT stored in association with the execution ID from being used to determine the warning condition and the correction condition. For example, the processor 110 deletes all the times ΔT associated with the execution ID. After the process of step ST27, the process returns to step ST11.

[0066] The operator of the teaching device 400 or the like receives a notification based on the notification process, for example, by viewing a warning screen, and modifies the robot program. In order to modify the robot program, the operator or the like operates, for example, the input device 460 to input an instruction to change the robot program. The input is input to the robot control device 100 via, for example, the communication interface 150.

[0067] If the processor 110 determines that the robot program is to be changed during the standby state of steps ST11 to ST14, the result of the determination in step ST14 is Yes, and the process proceeds to step ST28. In step ST28, the processor 110 changes the robot program based on an input instructing the change content of the robot program. The input is based on, for example, an operation input by an operator of the teaching device 400. The input is input, for example, via the communication interface 150. Note that the robot program changed here is not limited to the robot program that is the target of the notification process.

[0068] In step ST29, processor 110 determines whether the start position of arc welding has been changed for the robot program changed in step ST28. If the start position has not been changed, processor 110 determines No in step ST29, and the process returns to step ST11. On the other hand, if the start position has been changed, processor 110 determines Yes in step ST29, and the process proceeds to step ST30.

[0069] In step ST30, the processor 110 performs a reset process on the robot program changed in step ST28. That is, the processor 110 prevents the time ΔT stored in association with the program ID of the robot program from being used to determine the warning condition and the correction condition. For example, the processor 110 deletes all the times ΔT associated with the program ID. After the process of step ST30, the process returns to step ST11.

[0070] According to the embodiment of the welding system 1, when the time ΔT from the output of the welding start command to the input of the occurrence notification or the statistics of the time ΔT is equal to or less than a predetermined threshold, the robot controller 100 executes a predetermined process such as a warning process or a correction process. This leads to the robot controller 100 preventing the occurrence of a touch start, and improves the welding quality compared to the conventional case.

[0071] Furthermore, according to the welding system 1 of the embodiment, the robot control device 100 executes a predetermined process when the number of times Δ equal to or less than a predetermined threshold is equal to or greater than a predetermined number. This makes it possible for the welding system 1 of the embodiment to prevent the predetermined process from being executed based on the result of measuring the time ΔT only once, for example, when the time ΔT is an outlier.

[0072] Furthermore, according to the welding system 1 of the embodiment, the robot control device 100 can use, for example, an average value, a median value, a minimum value, or a maximum value as the statistics of the time ΔT. This allows the robot control device 100 of the embodiment to potentially execute a predetermined process when a touch start is likely to occur.

[0073] Furthermore, according to the welding system 1 of the embodiment, the robot control device 100 performs a warning process as a predetermined process. This allows the robot control device 100 to prompt the operator of the robot control device 100 to modify the program so as to suppress the occurrence of a touch start.

[0074] Furthermore, according to the welding system 1 of the embodiment, the robot control device 100 changes the robot program as a predetermined process to move the welding start position away from the robot, thereby enabling the robot control device 100 to reduce the possibility of a touch start occurring.

[0075] Furthermore, according to the welding system 1 of the embodiment, the robot controller 100 performs a reset process when the start position is changed. This prevents the robot controller 100 from using data on the time ΔT before the start position is changed in the warning condition and the correction condition.

[0076] The above embodiment can be modified as follows. The processor 110 may perform a reset process if the robot program is changed even if the starting position has not been changed.

[0077] The welding robot 200 may use a filler material other than a welding wire.

[0078] The arc welder according to the embodiment may not include a robot arm.

[0079] The processor 110 or the processor 410 may implement part or all of the processing implemented by the program in the above-described embodiments by a hardware circuit configuration.

[0080] The program for implementing the process of the embodiment is transferred, for example, in a state stored in the device. However, the device may be transferred without the program stored therein. The program may be transferred separately and written to the device. The program may be transferred, for example, by recording it on a removable storage medium or by downloading it via a network such as the Internet or a LAN (local area network).

[0081] Although the embodiment of the present invention has been described above, it is merely an example and does not limit the scope of the present invention. The embodiment of the present invention can be implemented in various forms without departing from the gist of the present invention. [Explanation of symbols]

[0082] 1 Welding system 100 Robot control device 110,410 processors 120,420 ROM 130,430 RAM 140,440 Auxiliary storage 150,450 Communication Interface 160 Control Interface 170 Welding Interface 180,480 Bus 200 Welding Robot 210 Drive unit 220 Wire Feeder 230 Welding Torch 300 Arc Welding Machine 400 Teaching device 460 Input Devices 470 Display Device OB welding object

Claims

1. An input / output unit that outputs first information instructing an arc welding machine to start welding and receives input of second information indicating the generation of an arc by the arc welding machine; A measurement unit that measures a time from an output of the first information to an input of the second information; A control device comprising: a processing unit that performs a predetermined process when the number or ratio of the times that are equal to or less than a first threshold value among the times measured multiple times is equal to or greater than a second threshold value.

2. An input / output unit that outputs first information instructing an arc welding machine to start welding and receives input of second information indicating the generation of an arc by the arc welding machine; A measurement unit that measures a time from an output of the first information to an input of the second information; A processing unit that performs a predetermined process when the average value, median value, minimum value, or maximum value of the time is equal to or less than a first threshold value.

3. An input / output unit that outputs first information instructing an arc welding machine to start welding and receives input of second information indicating the generation of an arc by the arc welding machine; A measurement unit that measures a time from an output of the first information to an input of the second information; a processing unit that performs a predetermined process when the time or a statistic of the time is equal to or less than a first threshold value. The processing unit is a control device that issues a notification indicating that a program that determines a start position of the welding is to be modified as the predetermined process.

4. An input / output unit that outputs first information instructing an arc welding machine to start welding and receives input of second information indicating the generation of an arc by the arc welding machine; A measurement unit that measures a time from an output of the first information to an input of the second information; a processing unit that performs a predetermined process when the time or a statistic of the time is equal to or less than a first threshold value. The processing unit changes a program that determines a start position of the welding as the predetermined process, thereby moving the start position away from the workpieces to be welded.

5. A control device and an arc welder, The control device includes: an input / output unit that outputs first information instructing an arc welder to start welding and receives input of second information indicating generation of an arc by the arc welder; A measurement unit that measures a time from an output of the first information to an input of the second information; a processing unit that performs a predetermined process when the number or ratio of the times that are equal to or less than the first threshold among the times measured a plurality of times is equal to or greater than a second threshold, The arc welding machine includes: a generating unit that receives the first information and generates an arc; an output unit that outputs the second information when an arc is generated by the generation unit.

6. A control device and an arc welder, The control device includes: an input / output unit that outputs first information instructing an arc welder to start welding and receives input of second information indicating generation of an arc by the arc welder; A measurement unit that measures a time from an output of the first information to an input of the second information; a processing unit that performs a predetermined process when the average value, the median value, the minimum value, or the maximum value of the time is equal to or less than a first threshold value, The arc welding machine includes: a generating unit that receives the first information and generates an arc; an output unit that outputs the second information when an arc is generated by the generation unit.

7. A control device and an arc welder, The control device includes: an input / output unit that outputs first information instructing an arc welder to start welding and receives input of second information indicating generation of an arc by the arc welder; A measurement unit that measures a time from an output of the first information to an input of the second information; a processing unit that performs a predetermined process when the time or a statistic of the time is equal to or less than a first threshold value, The processing unit, as the predetermined process, issues a notification indicating that a program for determining a start position of the welding is to be modified, The arc welding machine includes: a generating unit that receives the first information and generates an arc; an output unit that outputs the second information when an arc is generated by the generation unit.

8. A control device and an arc welder, The control device includes: an input / output unit that outputs first information instructing an arc welder to start welding and receives input of second information indicating generation of an arc by the arc welder; A measurement unit that measures a time from an output of the first information to an input of the second information; a processing unit that performs a predetermined process when the time or a statistic of the time is equal to or less than a first threshold value, The processing unit, as the predetermined process, changes a program that determines a start position of the welding to move the start position away from an object to be welded, The arc welding machine includes: a generating unit that receives the first information and generates an arc; an output unit that outputs the second information when an arc is generated by the generation unit.

9. A processor provided in a control device having an input / output unit, an input / output control unit that outputs first information instructing an arc welder to start welding and controls the input / output unit to receive second information indicating generation of an arc by the arc welder; A measurement unit that measures a time from an output of the first information to an input of the second information; A program that functions as a processing unit that performs a predetermined process when the number or ratio of the times that are equal to or less than a first threshold among the times measured multiple times is equal to or greater than a second threshold.

10. A processor provided in a control device having an input / output unit, an input / output control unit that outputs first information instructing an arc welder to start welding and controls the input / output unit to receive second information indicating generation of an arc by the arc welder; A measurement unit that measures a time from an output of the first information to an input of the second information; A program that functions as a processing unit that performs a predetermined process when the average, median, minimum, or maximum value of the time is equal to or less than a first threshold value.

11. A processor provided in a control device having an input / output unit, an input / output control unit that outputs first information instructing an arc welder to start welding and controls the input / output unit to receive second information indicating generation of an arc by the arc welder; A measurement unit that measures a time from an output of the first information to an input of the second information; a processing unit that performs a predetermined process when the time or a statistic of the time is equal to or less than a first threshold value; The processing unit is a program that issues a notification indicating that a program that determines a start position of welding is to be modified as the predetermined process.

12. A processor provided in a control device having an input / output unit, an input / output control unit that outputs first information instructing an arc welder to start welding and controls the input / output unit to receive second information indicating generation of an arc by the arc welder; A measurement unit that measures a time from an output of the first information to an input of the second information; a processing unit that performs a predetermined process when the time or a statistic of the time is equal to or less than a first threshold value; The processing unit, as the predetermined process, changes a program that determines a start position of the welding to move the start position away from the workpieces to be welded.

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