JP7304224B2 - Controllers, programs, and robot control systems - Google Patents

Description

The present invention relates to a controller, program, and robot control system.

A contact tip (power supply tip, welding tip) used in a welding torch of a welding robot wears due to friction with a welding wire during welding and deformation due to heat during power supply. Due to wear inside the contact tip, the welding wire comes out in a bent state, which increases the resistance value of the wire current-carrying part. As a result, the actual current value is lower than the current command value, which is one of the factors that degrade the welding quality. Therefore, techniques for periodically exchanging contact tips have been proposed. For example, Patent Literature 1 discloses a technique for determining that it is time to replace a contact tip when the monitored current representative value and voltage representative value show a negative correlation.

JP 2017-64720 A

The prior art including Patent Document 1 is basically a technology for a small-variety mass production line, and is a technology that works favorably for the same welding section and welding object. In other words, it is assumed that the current command value and voltage command value notified to the welding machine are approximately the same value. It is better to estimate the replacement time. In this regard, in order to cope with the case of a high-mix low-volume production line, etc., the replacement timing of the contact tip is estimated so that it can correspond to various current command values and voltage command values set in various welding target sections. New methods are needed.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a control device, a program, and a robot control system that are highly versatile and capable of suitably estimating the contact tip replacement timing.

A control device according to an aspect of the present invention includes an acquisition unit that acquires command values and measured values of welding parameters during welding for each of a plurality of welding sections including different welding sections; a calculation unit for calculating a difference value between an average command value indicating the average of the command values in the section and an average command value indicating the average of the measured values; and an output unit for outputting the exchange information.

In this aspect, as the wear of the contact tip progresses, the welding wire comes out in a bent state, and the resistance value of the wire current-carrying part tends to increase. It focuses on the fact that the divergence between the command value and the measured value of the welding parameter such as welding parameter and voltage increases. For example, the deviation between the command value and the measured value of the welding parameter is represented by a difference value, and when this difference value becomes large, it can be estimated that it is time to replace the contact tip. In other words, according to this aspect, by estimating the replacement time based on the deviation between the command value and the measured value of the welding parameter, various welding sections can be handled, and versatility is increased, and the command value and the measured value are improved. By using the degree of divergence from the value, it is possible to appropriately estimate the replacement timing of the contact tip.

In the above aspect, the calculator may calculate a ratio of the difference value to the average measured value, and the generator may use the ratio to generate the replacement information. As a result, the larger the command value, the larger the difference value from the measured value. Therefore, in order to reduce the influence of the difference in the difference value due to the difference in the command value, the ratio of the difference value to the command value is used for replacement. By generating the information, it becomes possible to more appropriately estimate the replacement timing while increasing versatility.

In the above aspect, when the difference value is equal to or greater than a threshold value, the generation unit includes information indicating the arrival of the replacement time for the replacement object in the replacement information, and sets the threshold value according to the variance of the average command value. can be changed by As a result, if the variance of the original command value is large, the variance of the difference value tends to be large as well. Therefore, by changing the threshold for determining the replacement timing using the variance of the average command value, the threshold becomes a more appropriate value. Become. As a result, it becomes possible to more appropriately estimate the replacement timing while improving versatility.

In the above aspect, the calculator may calculate the variance of the difference value, and the generator may generate the exchange information according to a comparison result between the variance and a threshold value. As a result, if the variance of the original command value is large, the variance of the difference value tends to be large. It is possible to estimate the replacement timing more appropriately while increasing the

Advantageous Effects of Invention According to the present invention, it is possible to provide a control device, a program, and a robot control system that are highly versatile and can suitably estimate the contact tip replacement time.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows an example of a schematic structure of the robot control system 1 provided with the arc-welding abnormality determination system which concerns on embodiment. 3 is a block diagram showing an example of functions of a processing unit 214 according to an embodiment; FIG. It is a figure which shows an example of the relationship of the command value and measured value of the welding current in the predetermined welding area which concerns on embodiment. It is a figure showing an example of an average current measurement value in a plurality of welding sections concerning an embodiment. FIG. 5 is a diagram for explaining a deviation between an average command value and an average measured value of current for each welding operation according to the embodiment; It is a figure which shows an example of the welding abnormality which concerns on embodiment. 4 is a flow chart showing an example of a contact tip replacement timing determination procedure according to the embodiment.

Preferred embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that, in each figure, the same reference numerals have the same or similar configurations.

<Overall composition>
FIG. 1 is a diagram showing an example of a schematic configuration of a robot control system 1 equipped with an arc welding abnormality determination system according to one embodiment of the present invention. FIG. 1 is also a diagram including an example of functional blocks of the robot control system 1 . The robot control system 1 performs arc welding (hereinafter also simply referred to as “welding”) on a workpiece W by a program-controlled articulated robot. The robot control system 1 includes a robot (for example, a manipulator) 10, a robot control device 20, an input/output terminal 30, and a welding machine 40 including a welding power source and the like. Although the robot control device 20 and the robot 10 are the minimum configuration of the disclosed "robot control system", the input/output terminal 30 and the welding machine 40 may be included to configure the "robot control system". The robot control device 20 and the input/output terminal 30 may be configured integrally with each other, or may be configured separately from each other as shown in FIG.

The robot control system 1 includes, for example, various cables that interconnect the robot control device 20 and various devices, and the robot control device 20 communicates with the various devices. The robot control system 1 also includes a power cable or the like for supplying a high-voltage welding voltage Vs between the welding wire 14 and the workpiece W, which will be described later.

(robot 10)
The robot 10 performs arc welding on the workpiece W under the control of the robot control device 20 , the input/output terminal 30 and the welding machine 40 . The robot 10 includes robot motors 101 controlled by movement commands output by the servo controller 23 . By driving the robot motor 101, movement of the articulated arm and the like are controlled. The robot 10 also has a welding torch 13 connected to the tip of an articulated arm, a wire feeding device fixed to the articulated arm or the like, and a workbench 11 .

One end (tip) of the articulated arm is connected to a welding torch 13 , and a welding wire 14 as a filler material is exposed at the tip of the welding torch 13 . The welding torch 13 performs arc welding on the work W by generating an arc between the tip of the welding wire 14 and the work W, and melting the welding wire 14 and the work W with the heat of the arc. be. Welding torch 13 has a contact tip (not shown) electrically connected to a cable. The contact tip (hereinafter also referred to as “tip”) is configured to supply the welding wire 14 with the welding voltage Vs supplied from the cable. Due to wear of the contact tip, measured values of welding parameters, which will be described later, deviate from command values.

(Robot control device 20)
Robot controller 20 controls robot 10 and welder 40 according to instructions from controller 21 . The robot control device 20 further uses the measured value of the welding parameter to determine the threshold value of the welding abnormality. The robot control device 20 includes a control section 21, a storage section 22, and a servo control section 23 in order to perform the processing described above.

The storage unit 22 includes a welding condition storage unit 22A, a program storage unit 22B, and a sampling buffer 22C, and can store various programs and various data files.

The welding condition storage unit 22A stores, for example, the set values of the welding current Is, the welding voltage Vs, the wire feed speed Vf and the welding speed Vw, the threshold values for determining the contact tip replacement timing, and the welding abnormality determination. Thresholds and the like to be used are stored.

The program storage unit 22B stores a control program for controlling the motion of the articulated arm, a determination program used for determining when to replace the contact tip, and the like. The control program and determination program are stored in, for example, a ROM (read only memory). In addition, the program storage unit 22B stores one or a plurality of work programs in which the welding work procedure of the robot 10 is taught. One or more work programs are stored, for example, on a hard disk.

The sampling buffer 22C stores various data generated by executing the determination program. These various data are stored in, for example, a RAM (Random Access Memory).

The various data are, for example, the measured value of the welding current Is during welding, the measured value of the welding voltage Vs obtained from the welding machine 40, the measured value of the wire feed speed Vf, and the measured value of the welding speed Vw. value.

The servo control unit 23 controls each robot motor 101 of the robot 10 . The servo control unit 23 controls each robot motor 101 of the robot 10 based on the movement command described in the work program and the position information from the encoder of the robot 10 . Movement instructions may include, for example, movement start instructions, movement stop instructions, work paths (teach points), and torch attitudes. Also, the servo control unit 23 derives (measures) the welding speed Vw based on the position information from the encoder of the robot 10 . Servo controller 23 outputs welding speed Vw to controller 21 .

The control unit 21 has an analysis unit 211 that reads out a work program or a contact tip replacement timing determination program based on a work command input from the input/output terminal 30 and analyzes the contents thereof. The analysis unit 211 generates instruction notifications corresponding to the instructions described in these programs based on the analysis results.

The control unit 21 has an execution unit 212 that outputs a movement command or a welding command according to the content of the command notification generated by the analysis unit 211 . The execution unit 212 generates a notification (monitoring start notification) for starting monitoring based on the determination program, for example, according to monitor information (for example, arc generation notification) input from the welding machine 40 . The execution unit 212 also generates a notification (monitoring end notification) for terminating monitoring based on the determination program, for example, according to the welding distance. The welding distance is derived from, for example, welding speed Vw×arcing time At. The execution unit 212 derives the welding distance using the welding speed Vw input from the servo control unit 23 and the time (arc time) after receiving the arc generation notification.

Control unit 21 has welding control unit 213 that outputs a voltage command value and a current command value to welding machine 40 based on the welding command generated by execution unit 212 . Welding control unit 213 notifies welding power source 401 of welding machine 40 of, for example, a voltage command value and a current command value together with a welding command.

The control unit 21 has a processing unit 214 that executes a contact tip replacement timing determination program in accordance with a monitoring start notification from the execution unit 212 . The processing unit 214, which will be described later with reference to FIG. 2, calculates a difference value between the command value and the measured value of the welding parameter stored in the sampling buffer 22C, and uses this difference value or the variance of the difference value to obtain a contact tip. determine when to replace the By using this difference value or variance, it is possible to reduce the influence of fluctuations in the command value according to various welding sections, and to cope with high-mix low-volume production lines. In addition, by focusing on the fact that the difference between the command value and the measured value of the welding parameter diverges as the replacement target such as the contact tip of the welding torch 13 wears, the replacement target can be automatically replaced. be able to determine the time. Note that the processing unit 214 may acquire, from the welding condition storage unit 22A, the threshold value for determining the replacement timing of the replacement target object.

By communicating with the welding machine 40, the control unit 21 synchronizes with the welding machine 40, and instructs, for example, the start and end of arc welding, the setting of the welding voltage Vs, or the setting of the wire feed speed Vf. . Further, the control unit 21 instructs the welding machine 40 to control the wire feeding device, and controls the welding wire 14 from the welding machine 40 to the wire feeding device, for example, to start or end arc welding, or to change the welding voltage. Instructs the setting of Vs and the like.

(Input/output terminal 30)
The input/output terminal 30 is a device for teaching the operation of the robot 10 by an operator. The input/output terminal 30 is, for example, a computer or the like, and has a control section, a display section, an input section, a communication section, and a storage section included in a general computer.

The display unit of the input/output terminal 30 displays an image when the image signal is input. For example, a graph or the like showing the arc welding abnormality determination result is displayed. The input unit of the input/output terminal 30 receives instructions from the operator, generates an input signal according to the operator's operation, and outputs the input signal to the control unit. A communication unit of the input/output terminal 30 communicates with the robot control device 20 via a cable, and transmits a work command from the control unit to the robot control device 20 . The communication unit also receives monitoring information from the robot control device 20 and outputs it to the control unit. The storage unit of the input/output terminal 30 stores a teaching program that enables various displays and work instructions in various modes. A teaching program is stored in, for example, a ROM.

The control unit of the input/output terminal 30 generates a video signal and outputs it to the display unit, and also generates a work command as necessary and outputs it to the communication unit. The control unit generates a video signal according to the read teaching program and generates a work command as necessary. For example, when acquiring monitoring information from the communication unit, the control unit generates a video signal for displaying the acquired monitoring information.

(Welder 40)
The welding machine 40 generates an arc between the tip of the welding wire 14 and the workpiece W by controlling the welding current Is, the welding voltage Vs, the wire feed speed Vf, etc. under the control of the robot controller 20. Let The welder 40 has a welding power source 401, a welding monitor 402, and the like.

The welder 40 controls the operation of the wire feeder based on welding commands from the robot controller 20 . The welding command from the robot controller 20 may include, for example, a voltage command, a current command, a wire feed start command, a wire feed stop command, and a set value for the wire feed speed Vf.

The welding power source 401 has, for example, a digital inverter circuit, and performs high-speed response and precise welding current waveform control on an externally input commercial power source (eg, 3-phase 200 V) by the inverter control circuit. That is, the welding power source 401 supplies a high welding voltage Vs between the welding torch 13 and the workpiece W. As shown in FIG. Welding power source 401 controls welding current Is and welding voltage Vs according to the voltage command value and current command value from robot controller 20 . The welding command from the robot controller 20 includes, for example, an arc welding start command, an arc welding end command, a set value of the welding current Is included in the current command, or a set value of the welding voltage Vs included in the voltage command. can be included.

The welding monitor 402 measures the welding current Is flowing between the welding torch 13 and the work W and the welding voltage Vs between the welding torch 13 and the work W. Welding monitoring unit 402 outputs the measured values of welding current Is and welding voltage Vs to sampling buffer 22C of robot controller 20 . Welding monitoring unit 402 measures wire feeding speed Vf based on the pulse output from the motor of the wire feeding device (or any signal in place of the above pulse), and measures wire feeding speed Vf. The value is output to the sampling buffer 22C of the robot controller 20. FIG.

(Determination processing of contact tip replacement timing)
FIG. 2 is a block diagram showing an example of functions of the processing unit 214 according to the embodiment. In the example illustrated in FIG. 2 , the processing unit 214 includes an acquisition unit 302 , a calculation unit 304 , a generation unit 306 and an output unit 308 . Note that the welding process according to the present disclosure is not limited to the same welding target and welding section, and can be applied to various welding targets and welding sections.

Acquisition unit 302 acquires command values and measured values of welding parameters during welding for each of a plurality of welded sections including different welded sections. For example, the acquisition unit 302 acquires the command value of the welding parameter in a predetermined welding section from the welding condition storage unit 22A, and acquires the measured value corresponding to the command value of the welding parameter from the sampling buffer 22C. The acquiring unit 302 may acquire command values and measured values of welding parameters in a predetermined welding section each time welding is completed in the welding section, and collect the welding parameters in a plurality of welding sections at a predetermined timing. You may acquire the command value and measured value of.

The calculation unit 304 calculates, for each predetermined welding section, a difference value between an average command value indicating the average of the command values of the welding parameters in the welding section and an average measured value indicating the average of the measured values. Alternatively, the calculation unit 304 calculates the variance of this difference value. For example, the calculation unit 304 calculates the average value of the command values (average command value) and the average value of the measured values (average measured value) at a plurality of time points within one welding section. Next, the calculator 304 calculates a difference value between the average command value and the average measured value. Note that the calculation unit 304 may calculate at least one difference value for each welded section.

The generation unit 306 generates replacement information for the replacement target object in the welding torch using the difference value or variance calculated by the calculation unit 304 . The exchange object is, for example, a contact tip. The replacement information is, for example, information about the replacement time, and includes information indicating that the replacement time is near, information indicating that the replacement time has come, and the like.

Specifically, the generating unit 306 compares the difference value or variance with a threshold value, and includes information indicating that it is time to replace the replacement information when determining that the difference value or variance is equal to or greater than the threshold value. In addition, if there are multiple thresholds, for example, if there are a first threshold, a second threshold, and a third threshold, the generation unit 306 generates the following exchange information when the difference value or variance and each threshold have the following relationship: to generate
Relationship between difference value or variance and threshold Exchange information difference value or variance < 1st threshold Information indicating that there is a margin until replacement time 1st threshold ≤ difference value or variance < 2nd threshold Information difference indicating that replacement time is near Value or variance≧second threshold Information indicating that it is time to replace

The output unit 308 outputs the exchange information generated by the generation unit 306. FIG. For example, the output unit 308 outputs exchange information to the input/output terminal 30 . Also, the output unit 308 may transmit the exchange information to a preset destination. Therefore, the operator can grasp the replacement timing of the replacement object by looking at the replacement information displayed or notified on the display unit.

In the disclosed embodiment, as the wear of the contact tip progresses, the welding wire comes out in a bent state, and the resistance value of the wire current-carrying part tends to increase. It focuses on the large divergence between command values and measured values of welding parameters such as current and voltage. For example, the difference between the command value and the measured value of the welding parameter is represented by the difference value between the command value and the measured value, and when this difference value becomes large, it can be estimated that it is time to replace the contact tip. That is, according to the above-described aspect, by estimating the replacement time based on the deviation between the command value and the measured value of the welding parameter, various welding sections can be handled, and versatility is increased. By using the degree of divergence from the measured value, it is possible to appropriately estimate the contact tip replacement timing. Moreover, in order to reduce the influence of differences in the original welding parameter command values, the generation unit 306 may generate exchange information using the variance of the difference values.

Further, the calculating unit 304 may calculate the ratio of the difference value to the average measured value, and the generating unit 306 may generate exchange information using this ratio. For example, if the current command values are 100A and 200A
Assuming that the respective measured values are 80A and 180A, the calculation unit 304 calculates the ratio using the following formula.
Ratio (degree of divergence [%]) = (average command value - average measured value) / average command value x 100
The generation unit 306 compares the calculated ratio with a threshold, and if the ratio is equal to or greater than the threshold, an abnormality has occurred in the welding and it is determined that it is time to replace the object to be replaced.

As a result, the larger the command value, the larger the difference value from the measured value. Therefore, in order to reduce the influence of the difference in the difference value due to the difference in the command value, the ratio of the difference value to the command value is used for replacement. By generating the information, it becomes possible to more appropriately estimate the replacement timing while increasing versatility.

Further, the calculation unit 304 may calculate the ratio between the command value and the reference value, which may take different values, and multiply the difference value by this ratio to update the difference value. For example, when the welding parameter is the welding current, the current command value set in welding control section 213 differs according to the welding section. Since the larger the current command value, the larger the difference value tends to be, the difference value tends to vary more when the current command value is large than when the current command value is small. Therefore, in order to reduce the influence of the variation in the difference value due to the difference in the current command value, the calculation unit 304 calculates the ratio for converting the current command value into the reference value, multiplies the difference value by this ratio, and obtains the difference value. Update value.

Here, as an example, the current command values are 60A, 80A, and 100A, the respective measured values are 58A, 76A, and 94A, and the current reference value is 80A. In this case, the calculator 304 obtains the ratio between the current command value and the reference value (=reference value/current command value), and multiplies the difference value by each ratio. Thereby, the difference value is updated as follows.
First difference value after update=(58−60)×(80/60)
Second difference value after update=(76−80)×(80/80)
Third difference value after update=(94−100)×(80/100)

As a result, the larger the command value, the larger the difference value from the measured value. By updating the difference value, it becomes possible to estimate the replacement timing more appropriately while improving versatility.

Further, the calculation unit 304 divides the command values of the welding parameters into a plurality of groups based on the values of the command values, calculates the ratio between the command value in the group and the reference value for each group, and calculates the ratio of the command value in the group to the reference value. The difference value may be updated by multiplying the difference value by the ratio. For example, when a current command value is used as a welding parameter, the calculation unit 304 calculates a first group of 80 A or less, a second group of 81 A to 100 A, a third group of 101 A to 120 A, and a current command value of 121 A or more. Divide into a fourth group. Next, the calculation unit 304 sets 70A as the reference value for the first group, 90A as the reference value for the second group, 110A as the reference value for the third group, and 130A as the reference value for the fourth group. Calculation unit 304 obtains the ratio between the current command value and the reference value for each group, and multiplies the difference value within the group by this ratio for updating.

As a result, the unit for standardizing the command value is further subdivided, so the influence of the variation in the difference value due to the difference in the command value can be reduced. It becomes possible to estimate the replacement timing.

Further, when the difference value calculated by the calculation unit 304 is equal to or greater than the threshold, the generation unit 306 includes information indicating the arrival of the contact tip replacement time in the replacement information, and uses this threshold as the variance of the average command value. may be changed accordingly. For example, the generation unit 306 changes the threshold according to the command value range between the minimum value and the maximum value of the current command value. Specifically, generation unit 306 increases the threshold as the command value range increases.

As a result, if the variance of the original command value is large, the variance of the difference value also tends to be large. Therefore, by changing the threshold for determining the replacement time using the variance of the command value, the threshold becomes a more appropriate value. . As a result, it becomes possible to more appropriately estimate the replacement timing while improving versatility.

Although the welding current is used as an example of the welding parameter, other parameters such as the welding voltage and the feed load (=motor rated current/motor current×100) may be used.

<Specific example>
Hereinafter, the disclosed processing for determining the replacement timing of the replacement object will be described with reference to FIGS. 3 to 6 . FIG. 3 is a diagram showing an example of the relationship between a welding current command value and a measured value in a predetermined welding section according to the embodiment. In the example shown in FIG. 3, the horizontal axis indicates time, the vertical axis indicates the magnitude of the welding current, the solid line indicates the command value, and the dotted line indicates the measured value.

FIG. 4 is a diagram showing an example of average current measurement values in a plurality of welded sections according to the embodiment; In the example shown in FIG. 4, the welded sections (1), (2), and (3) are different sections to be welded, and the average welding current measurement values measured from these welded sections are also different. The current values plotted in FIG. 4 indicate average values of welding current values measured in the weld zone. For example, the calculator 304 obtains the average value of the dotted line waveform shown in FIG.

FIG. 5 is a diagram for explaining the divergence between the average command value and the average measured value of the current for each welding according to the embodiment. In the example shown in FIG. 5, 110 A and 115 A are used as the average command values, and the difference values between each average command value and the corresponding average current measurement value are plotted on the distribution diagram. T1 and T2 shown in FIG. 5 indicate the time points at which the contact tip is replaced. As shown in FIG. 5, immediately after T1 and T2, the contact tip is not consumed, so the difference between the command value and the measured value is small, and as time passes from T1 and T2, the contact tip wears. The wear progresses, and the divergence between the command value and the measured value increases. Therefore, the generation unit 306 performs a threshold determination on the difference value between the command value and the measured value. Include in exchange information.

FIG. 6 is a diagram showing an example of a welding abnormality according to the embodiment. FIG. 6 shows a welding abnormality that occurred in the weld zone P1 shown in FIG. As shown in FIG. 6, the welding abnormality occurs before the contact tip replacement timing (time T2), and further, the welding abnormality occurs in the welding section where the divergence between the command value and the measured value is large.

<Action>
FIG. 7 is a flowchart showing an example of a contact tip replacement time determination procedure according to the embodiment. In the example shown in FIG. 7, a contact tip (chip) is used as an example of an object to be exchanged, and a welding current is used as an example of a welding parameter.

In step S102, the acquisition unit 302 acquires the command value and the measured value of the welding current during welding for each of a plurality of welding sections including different welding sections. The acquired command value and measured value may be average values.

At step S104, the calculation unit 304 calculates a difference value between the command value and the measured value for each welding section. When a plurality of command values and measured values are acquired in the welded section, the calculation unit 304 may calculate an average value of each of the command values and the measured values.

In step S106, the calculator 304 calculates the variance of the difference values. The calculator 306 calculates the variance each time the difference value is calculated. Further, when the exchange target is exchanged, the calculator 306 resets the difference value used to calculate the variance. The exchange of the exchange target object may be instructed by the operator, and the generation unit 306, after exceeding the threshold (first threshold), when the variance becomes equal to or less than the second threshold (< the first threshold), You may judge that it was exchanged. Note that step 106 is not an essential process.

In step S108, the generator 306 compares the difference value or variance with a threshold. The generation unit 306 can determine that it is time to replace the object to be replaced when the difference value or the variance is greater than or equal to the threshold as a result of this comparison.

In step S110, the generation unit 308 generates exchange information based on the comparison result between the difference value or the variance and the threshold. For example, if the difference value or variance is less than the threshold, the generation unit 308 includes information indicating that the replacement time has not yet arrived in the replacement information. Include in the exchange information information indicating that

In step S<b>112 , the output unit 308 outputs the exchange information generated by the generation unit 306 . Alternatively, the output unit 308 may notify exchange information only when the difference value or variance is equal to or greater than a threshold.

By estimating the replacement timing based on the difference between the command value and the measured value of the welding parameter by the replacement timing determination procedure described above, the influence of the difference in the original welding parameter command value can be reduced, and various welding sections can be used. It becomes possible to deal with it, and versatility is improved, and by using the degree of divergence between the command value and the measured value, it becomes possible to appropriately estimate the replacement time of the contact tip.

Also, each process shown in FIG. 7 may be implemented as a determination program executed by a computer. This determination program is installed in the robot control device 20 or stored in a computer-readable storage medium (e.g., non-temporary storage medium) and executed by a computer control unit (e.g., processor, etc.). , the above process may be implemented.

Also, each function in the control section 21 of the robot control device 20 may be configured to function in the control section of the input/output terminal 30 . In this case, the sampling buffer 22C may be included in either the robot controller 20 or the input/output terminal 30. FIG.

The embodiments described above are for facilitating understanding of the present invention, and are not intended to limit and interpret the present invention. Each element included in the embodiment and its arrangement, materials, conditions, shape, size, etc. are not limited to those illustrated and can be changed as appropriate. For example, the processing steps described above can be arbitrarily changed in order or executed in parallel as long as the content of processing is not inconsistent.

DESCRIPTION OF SYMBOLS 1... Robot control system 10... Robot 11... Workbench 13... Welding torch 14... Welding wire 20... Robot control device 21... Control part 22... Storage part 30... Input/output terminal 40... Welding Machine 101 Robot motor 211 Analysis unit 212 Execution unit 213 Welding control unit 214 Processing unit 302 Acquisition unit 304 Calculation unit 306 Generation unit 308 Output unit 401 Welding power supply, 402 ... Welding monitoring unit.

Claims (6)

an acquiring unit that acquires command values and measured values of welding parameters during welding for each of a plurality of welded sections including different welded sections;
a calculation unit that calculates, for each welded section, a difference value between an average command value indicating the average of the command values in the welded section and an average measured value indicating the average of the measured values;
a generation unit that uses the difference value to generate contact tip replacement information for a welding torch;
an output unit that outputs the exchange information;
A control device comprising: The calculation unit
Calculate the ratio of the difference value to the average measured value,
The generating unit
2. The controller of claim 1, wherein said ratio is used to generate said exchange information. The generating unit
3. The method according to claim 1 or 2, wherein when the difference value is equal to or greater than a threshold value, information indicating that the contact tip replacement time has come is included in the replacement information, and the threshold value is changed according to the variance of the average command value. Control device as described. The calculation unit
calculating the variance of the difference value;
The generating unit
4. The control device according to any one of claims 1 to 3, wherein said exchange information is generated according to a comparison result between said variance and a threshold. to the computer,
an acquisition step of acquiring command values and measured values of welding parameters during welding for each of a plurality of welded sections including different welded sections;
a calculating step of calculating a difference value between an average command value indicating the average of the command values in the welding interval and an average command value indicating the average of the measured values for each of the welding intervals;
a generation step of generating contact tip replacement information in a welding torch using the difference value;
an output step of outputting the exchange information;
program to run. A robot control system including a robot and a controller that controls the robot to perform welding,
The control device is
an acquiring unit that acquires command values and measured values of welding parameters during welding for each of a plurality of welded sections including different welded sections;
a calculating unit for calculating, for each welded section, a difference value between an average command value indicating the average of the command values in the welded section and an average command value indicating the average of the measured values;
a generation unit that uses the difference value to generate contact tip replacement information for a welding torch;
an output unit that outputs the exchange information;
A robot control system with

Images