Welding teaching system, welding teaching method, welding teaching control method, and welding teaching control program

Abstract

To secure legal safety and conduct teaching related to welding of a robot.SOLUTION: A welding teaching system includes: a control device which selects, on the basis of a distance between a welding torch of a welding robot and a workpiece being an object to be welded, one of a first teaching mode or a second teaching mode as a teaching method for causing a welding robot to operate during welding; and a display device which presents the selected teaching method so that a worker can grasp the result intuitively.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a welding teaching system, a welding teaching method, a welding teaching control method, and a welding teaching control program. [Background technology]

[0002] Patent Document 1 discloses a wire touch sensing method for a welding robot, in which a welding wire to which a voltage is applied is moved, and when a short-circuit signal of the welding wire is detected, the welding wire is moved in the reverse direction at a low speed, and the position where the short-circuit release signal is detected is determined to be the actual position of the workpiece. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-170471 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure has been devised in consideration of the conventional circumstances, and aims to provide a welding teaching system, a welding teaching method, a welding teaching control method, and a welding teaching control program that easily teach a robot about welding while ensuring legal safety. [Means for solving the problem]

[0005] The present disclosure provides a welding teaching system comprising a control device that selects either a first teaching mode or a second teaching mode as a teaching method for operating a welding robot during welding based on the distance between the welding torch of the welding robot and the workpiece to be welded, and a display that presents the results of the selection of the teaching method in a way that allows a person to intuitively understand it.

[0006] The present disclosure also provides a welding teaching method that is executed by a welding teaching system comprising a control device and a display connected to a welding robot so as to be able to input and output signals therebetween, and that includes the steps of: using the control device to select either a first teaching mode or a second teaching mode as a teaching method for operating the welding robot during welding based on the distance between the welding torch of the welding robot and the workpiece that is the object to be welded; and using the display to present the selection result of the teaching method in a manner that allows a person to intuitively understand it.

[0007] The present disclosure also provides a welding teaching control method, which is executed by a control device connected to a welding robot and a display device so that signals can be input and output between the welding robot and the display device, and which includes the steps of selecting either a first teaching mode or a second teaching mode as a teaching method for operating the welding robot during welding based on the distance between the welding torch of the welding robot and a workpiece that is the object to be welded, and presenting the selection result of the teaching method on the display device so that a person can intuitively understand it.

[0008] The present disclosure also provides a welding teaching control program for causing a control device, which is a computer connected to a welding robot and a display so as to be able to input and output signals between the welding robot and the display, to realize the following steps: selecting either a first teaching mode or a second teaching mode as a teaching method for operating the welding robot during welding based on the distance between the welding torch of the welding robot and the workpiece, which is the object to be welded; and presenting the result of the selection of the teaching method on the display so that a person can intuitively understand it. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to easily teach a robot about welding while ensuring legal safety. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing a configuration example of a welding teaching system according to an embodiment of the present invention. [Figure 2] Enlarged view of the tip of the welding torch [Figure 3] FIG. 1 is a schematic diagram illustrating a first teaching mode and a second teaching mode; [Figure 4] An example of a notification screen displayed on the teaching pendant [Figure 5] A diagram showing an example of robot welding instruction [Figure 6] 1 is a flowchart showing an example of the operation procedure of a robot control device according to an embodiment of the present invention in chronological order. [Figure 7] FIG. 10 is a diagram showing a modified example of teaching in the second teaching mode. DETAILED DESCRIPTION OF THE INVENTION

[0011] (Background to this disclosure) When using industrial robots, for safety reasons, workers and other people cannot directly touch and operate them or teach them welding techniques (hereinafter referred to as "teaching"). On the other hand, collaborative robots, which can be operated and taught by humans through direct contact, are limited in their maximum speed to about one-third that of industrial robots for safety reasons. Therefore, while teaching using collaborative robots is intuitive and easy, the productivity of collaborative robots is inferior to that of industrial robots in the mass production of products that require welding. Therefore, there is a need for tools that can be used intuitively by humans when operating or teaching industrial robots without sacrificing the maximum speed of the robot's movement during production.

[0012] As a tool for intuitively teaching an industrial robot, in addition to direct teaching using a 3D mouse, the wire touch sensing method disclosed in Patent Document 1 is already known.

[0013] However, direct teaching using a 3D mouse is good at roughly teaching spatial positions, but has the problem of being poor at teaching precise positions in relation to the target (i.e., the workpiece to be welded) or teaching the posture of the welding torch.On the other hand, with teaching using the wire touch sensing method, it is possible to obtain precise positions when close to the target (i.e., the workpiece to be welded), but there is an issue that teaching is difficult when the target position is not specific.

[0014] Therefore, in the following embodiments, examples of a welding teaching system, a welding teaching method, a welding teaching control method, and a welding teaching control program that easily teach a robot about welding while ensuring legal safety will be described.

[0015] Hereinafter, with reference to the drawings as appropriate, detailed embodiments of the present disclosure will be described in detail. However, more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters and redundant descriptions of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure and are not intended to limit the subject matter recited in the claims.

[0016] 1. Configuration of welding teaching system First, with reference to FIG. 1, the configuration of a welding teaching system 100 according to this embodiment will be described.

[0017] FIG. 1 is a diagram showing an example of the configuration of a welding teaching system 100 according to the present embodiment. Welding teaching system 100 includes at least a welding robot 30, a robot control device 40, and a display 50. Welding teaching system 100 may also include a 3D mouse 10, a distance sensor 20, and a teaching pendant 51. Robot control device 40 is an example of a control device according to the present disclosure, and is connected to welding robot 30 and display 50 so as to enable input and output of data signals (an example of a signal). For example, welding robot 30 and robot control device 40 are connected by a wired cable (not shown) that transmits data signals to each other, and robot control device 40 and display 50 are connected by a wired cable (not shown) that transmits data signals to each other or wirelessly.

[0018] In this embodiment, the welding robot 30 is described as an industrial robot that cannot be operated or taught by direct human contact for safety reasons. However, it may also be a collaborative robot that can be operated or taught by direct human contact for safety reasons. The welding robot 30 is, for example, a vertically articulated robot having six degrees of freedom and configured with multiple robot arms 31. Note that the welding robot 30 does not have to be a vertically articulated robot having six degrees of freedom. The welding robot 30 is equipped with a welding torch (so-called welding torch 33) on the tip side (end effector side) opposite the base end side. Based on a robot control signal from the robot control device 40, the welding robot 30 feeds the welding wire 32 so that it protrudes a predetermined amount from the tip of the welding torch 33 (i.e., so that it approaches the workpiece Wk) during welding, and performs arc welding on the workpiece Wk (see FIG. 5 ), which is the object to be welded.

[0019] In this embodiment, to improve the efficiency of offline teaching, which teaches the position of welding torch 33 of welding robot 30 at each stage before welding begins, during welding, and after welding is completed, two operation modes are provided and a teaching tool is provided for each operation mode. The two operation modes are a first teaching mode and a second teaching mode.

[0020] In the first teaching mode, a 3D mouse 10 placed at the tip of welding torch 33 of welding robot 30 (see FIG. 2) is used. This 3D mouse 10 is mainly operated by a worker in a factory or the like who performs teaching, and an operation signal (see FIG. 2) generated when the worker operates 3D mouse 10 is sent from 3D mouse 10 directly or via teaching pendant 51 to robot control device 40, where it is processed. Details of teaching using the operation of 3D mouse 10 will be described later with reference to FIG. 2.

[0021] In the second teaching mode, a touch sensing method (see Patent Document 1) using the welding torch 33 is used. In the touch sensing method, the robot control device 40 applies a predetermined voltage to the welding wire 32 and constantly monitors whether or not there is a fluctuation in the voltage of the welding wire 32, and detects a short-circuit signal, which indicates that the voltage becomes zero, when the welding wire 32 has come into contact with the workpiece Wk. In other words, the robot control device 40 does not detect a short-circuit signal when the welding wire 32 is not in contact with the workpiece Wk, and therefore can detect whether or not the welding wire 32 has come into contact with the workpiece Wk based on whether or not a short-circuit signal is detected. Furthermore, the robot control device 40 can also determine the position at which the welding wire 32 is not in contact with the workpiece Wk based on the value of the voltage of the welding wire 32.

[0022] The 3D mouse 10 is a device capable of receiving various types of operations from the worker, and is fixed near the welding torch 33 located at the tip of the robot arm 31 of the welding robot 30. The 3D mouse 10 has a depression portion and is capable of detecting various types of operations performed on the depression portion by the worker. Various operations such as pressing, tilting, rotating, and translating can be performed on the depression portion.

[0023] Here, the relationship between the operation of the 3D mouse 10 and the movement of the welding torch 33 will be described with reference to Figure 2. Figure 2 is an enlarged view of the tip of the welding torch 33. Four different types of operations are input by the worker into the press-down section of the 3D mouse 10. The 3D mouse 10 and the robot control device 40 are connected by a wireless communication method such as Bluetooth (registered trademark), and the operation signal of the 3D mouse 10 is transmitted to the robot control device 40 by this wireless communication method.

[0024] When the teaching pendant 51 is connected between the 3D mouse 10 and the robot control device 40, the operation signal of the 3D mouse 10 is transmitted to the teaching pendant 51 via Bluetooth (registered trademark), and then transmitted from the teaching pendant 51 to the robot control device 40 via a wireless communication method. The method for wirelessly connecting the teaching pendant 51 and the robot control device 40 does not have to be Bluetooth (registered trademark), and may be, for example, Wifi (registered trademark) or another short-range wireless communication method.

[0025] (1) The first operation is an operation of holding and pressing the press-down portion, which sends an operation signal to store the current position of welding torch 33 as a teaching point. Upon receiving this operation signal, robot control device 40 stores the current position of welding torch 33 as a teaching point based on the operation signal from 3D mouse 10. (2) The second operation is an operation of tilting the push-down portion while gripping it, and an operation signal is sent to tilt the current position of welding torch 33 in accordance with this operation (tilting of the push-down portion). Upon receiving this operation signal, robot control device 40 performs a movement to tilt the current welding torch 33 based on the operation signal from 3D mouse 10. (3) The third operation is an operation of rotating the push-down portion while gripping it, and in accordance with this operation (rotation of the push-down portion), an operation signal is sent to rotate the current welding torch 33. Upon receiving this operation signal, the robot control device 40 performs a movement to rotate the current welding torch 33 based on the operation signal from the 3D mouse 10. (4) The fourth operation is an operation of moving the pressing part in parallel in three dimensions while holding it (XYZ parallel movement), and an operation signal is sent to move the current welding torch 33 in parallel in three dimensions in accordance with this operation (translation of the pressing part in three dimensions). Upon receiving this operation signal, robot control device 40 moves the current welding torch 33 in parallel in three dimensions based on the operation signal from 3D mouse 10.

[0026] The distance sensor 20 is fixed near the welding torch 33 located at the tip of the robot arm 31 of the welding robot 30 and measures the distance from the distance sensor 20 to the workpiece Wk, which is the object to be welded. The distance sensor 20 may be configured using, for example, a Time of Flight (TOF) sensor or a TOF camera; the distance measurement method is not important in this embodiment. For example, the distance sensor 20 can measure the distance to an object by emitting infrared rays in all directions and receiving the infrared rays reflected by the object. The distance (offset distance) from the position of the distance sensor 20 to the welding torch 33 (in other words, the tip of the welding wire 32) is known when the distance sensor 20 is fixed. Therefore, the distance sensor 20 can calculate the distance from the tip of the welding wire 32 to the workpiece Wk by subtracting the offset distance from the distance measured by its own device (i.e., the distance from the distance sensor 20 to the workpiece Wk). The distance sensor 20 transmits this calculation result (distance) to the robot control device 40. The signal transmission method between the distance sensor 20 and the robot control device 40 may be a wireless method such as Bluetooth (registered trademark) or Wifi (registered trademark).

[0027] The display 50 displays a notification screen (see FIGS. 4 and 7) generated by the robot control device 40. The display 50 may be configured using, for example, a Liquid Crystal Display (LCD) or an organic EL, or may be configured by a teaching pendant 51 described later.

[0028] The teaching pendant 51 is a worker terminal held and operated by the worker, and functions not only as an input device for inputting the worker's operations but also as a display device for displaying the screen of pre-installed application software. The teaching pendant 51 also has a wireless communication function using Bluetooth (registered trademark), and can transmit signals to and from the 3D mouse 10 via Bluetooth (registered trademark). The teaching pendant 51 can also transmit signals to and from the robot control device 40 using Wi-Fi (registered trademark) or other short-range wireless communication methods.

[0029] The robot control device 40 is a controller that controls the welding movement of the welding robot 30 on the workpiece Wk, which is the object to be welded. The robot control device 40 includes a communication I / F 41, a memory 42, and a processor 43. The communication I / F 41, the memory 42, and the processor 43 are connected to each other by wiring such as an internal bus so that data signals can be input and output.

[0030] The communication I / F 41 is configured using communication that controls the communication of data signals (data) with external devices (e.g., 3D mouse 10, distance sensor 20, welding robot 30, display 50, teaching pendant 51), and performs data communication with the above-mentioned external devices.

[0031] The memory 42 includes at least a random access memory (RAM) and a read only memory (ROM), for example, and temporarily stores programs necessary for the operation of the robot control device 40 and data acquired or generated during operation. The RAM is, for example, a work memory used during the operation of the robot control device 40. The ROM stores and stores in advance, for example, programs for controlling the robot control device 40.

[0032] The processor 43 includes at least one of a central processing unit (CPU), a digital signal processor (DSP), a field programmable gate array (FPGA), and a graphical processing unit (GPU). The processor 43 functions as a controller that manages the overall operation of the robot control device 40. The processor 43 performs control processing for overseeing the operation of each part of the robot control device 40, data input / output processing between each part of the robot control device 40, data calculation processing, and data storage processing. The processor 43 operates according to a program stored in the memory 42. The processor 43 cooperates using the memory 42 during operation, and temporarily stores data generated or acquired by the processor 43 in the memory 42. When the welding robot 30 is to be instructed on the position of the welding torch 33 specified in a welding program for welding, the processor 43 controls the operation mode related to the instruction, and specifically selects a first teaching mode or a second teaching mode as the operation mode. Furthermore, when both the welding robot 30 and the robot control device 40 are in operation, the processor 43 constantly acquires the current position information of the welding torch 33 based on a signal transmitted from the welding robot 30 .

[0033] Processor 43 also functionally includes a sensor input unit 43a, a 3D mouse operation control unit 43b, a touch sensor control unit 43c, and a teaching processing unit 43d as examples of hardware resources for executing the welding teaching control method. Teaching processing unit 43d also functionally includes an object distance determination unit 43d1 and an optimal teaching determination unit 43d2. The processing by each of sensor input unit 43a, 3D mouse operation control unit 43b, touch sensor control unit 43c, and teaching processing unit 43d is realized based on cooperation between processor 43 and memory 42. Note that at least one processor may be provided for each of sensor input unit 43a, 3D mouse operation control unit 43b, touch sensor control unit 43c, and teaching processing unit 43d.

[0034] The sensor input unit 43a inputs and outputs signals to and from the distance sensor 20, and based on the signal from the distance sensor 20, acquires and recognizes the calculation result of the current distance from the tip of the welding wire 32 to the workpiece Wk as workpiece position information 43a1.

[0035] 3D mouse operation control unit 43b inputs and outputs signals to and from 3D mouse 10, generates control signals for controlling the movement of welding torch 33 based on operation signals from 3D mouse 10 directly or via teaching pendant 51, sends the control signals to welding robot 30, and controls the movement of welding robot 30 based on the control signals. In this way, even for welding robot 30, which is an industrial robot, robot control device 40 can appropriately control the movement of welding torch 33 corresponding to the operation based on the operation signals generated by the operator operating 3D mouse 10.

[0036] Touch sensor control unit 43c controls the application of voltage to welding torch 33 and monitors whether or not the voltage fluctuates. Touch sensor control unit 43c applies a predetermined voltage to welding wire 32 and constantly monitors whether or not the voltage of welding wire 32 fluctuates, and detects a short-circuit signal that indicates that the voltage becomes zero when welding wire 32 comes into contact with workpiece Wk (touch sensor method). In other words, touch sensor control unit 43c detects whether or not welding wire 32 has come into contact with workpiece Wk depending on whether or not a short-circuit signal has been detected, and also determines the position at which welding wire 32 is not in contact with workpiece Wk depending on the value of the voltage of welding wire 32.

[0037] The instruction processing unit 43d controls the instruction of the position of the welding torch 33 specified in the welding program for the welding robot 30 to perform welding based on the output of the sensor input unit 43a (i.e., work position information 43a1) and the usage status of the 3D mouse operation control unit 43b and the touch sensor control unit 43c.

[0038] The object distance determination unit 43d1 determines the work position information 43a1 acquired by the sensor input unit 43a as torch tip current position information 43d3 indicating the distance from the current tip of the welding torch 33 (in other words, the tip of the welding wire 32) to the workpiece Wk, which is the object to be welded.

[0039] The optimal teaching determination unit 43d2 compares the torch tip current position information 43d3 determined by the object distance determination unit 43d1 with a predetermined threshold. If the optimal teaching determination unit 43d2 determines that the torch tip current position information 43d3 is equal to or greater than the predetermined threshold, it selects the first teaching mode as the operating mode during teaching of the robot control device 40. On the other hand, if the optimal teaching determination unit 43d2 determines that the torch tip current position information 43d3 is less than the predetermined threshold, it selects the second teaching mode as the operating mode during teaching of the robot control device 40. Details of the first teaching mode and the second teaching mode will be described later with reference to FIG. 3.

[0040] 2. Details of the 1st teaching mode and the 2nd teaching mode Next, the first teaching mode and the second teaching mode will be described in detail with reference to Fig. 3. Fig. 3 is a schematic diagram showing the first teaching mode and the second teaching mode. In Fig. 3, a workpiece Wk is an object to be welded by a welding robot 30.

[0041] When the distance between welding torch 33 of welding robot 30 and workpiece Wk (hereinafter sometimes referred to as the "measured distance") is equal to or greater than a predetermined threshold, robot control device 40 selects the first teaching mode as the operation mode during teaching. In the first teaching mode, the position and movement of welding torch 33 of welding robot 30 are recognized by robot control device 40 based on operation signals sent from 3D mouse 10 when the worker directly operates 3D mouse 10. This is because, when welding torch 33 and workpiece Wk are far enough apart that the measured distance is equal to or greater than the predetermined threshold, sufficient precision is not required for the position and movement of welding torch 33 during teaching, and there are no obstacles (e.g., a jig for fixing workpiece Wk, other equipment, etc.) placed around welding torch 33.

[0042] If the measured distance is less than a predetermined threshold, the robot control device 40 selects the second teaching mode as the operation mode during teaching. In the second teaching mode, the position and movement of the welding torch 33 of the welding robot 30 during welding are recognized by the robot control device 40 based on a touch sensor system using the welding wire 32. This is because if the welding torch 33 and the workpiece Wk are close enough that the measured distance is less than the predetermined threshold, the welding position will change if the welding wire 32 at the tip of the welding torch 33 comes into contact with the workpiece Wk during teaching, which will affect the welding quality. In other words, the second teaching mode requires high positional accuracy of the welding torch 33 (e.g., ±0.1 mm), so automatic teaching using the touch sensor system is more useful than manual teaching using the 3D mouse 10 by the operator.

[0043] Here, an example of a notification screen displayed on the teaching pendant 51 will be described with reference to Fig. 4. Fig. 4 is a diagram showing an example of a notification screen displayed on the teaching pendant 51. As described with reference to Fig. 1, the teaching pendant 51 may have a role of relaying an operation signal from the 3D mouse 10 to the robot control device 40, or may be configured as a display device 50.

[0044] Assume that an operator uses an input device (not shown) such as a mouse to instruct robot control device 40, which has installed therein a welding teaching control program for executing the welding teaching control method according to this embodiment, to generate a new program. Based on the instruction from the input device (not shown) used by the operator, processor 43 of robot control device 40 outputs and displays on display 50 or teaching pendant 51 a notification screen WD1 that, for example, indicates "Please attach a 3D mouse to the torch." This allows the operator to easily recognize that 3D mouse 10 must be attached to a predetermined position on welding torch 33 of welding robot 30 before starting teaching.

[0045] 3. Operation of the welding teaching system (welding teaching method) Next, the operation (welding teaching method) of welding teaching system 100 according to this embodiment will be described with reference to Figs. 5 to 7. Fig. 5 is a diagram showing an example of teaching related to robot welding. Fig. 6 is a flowchart showing an example of the operation procedure of the robot control device according to this embodiment in chronological order. Fig. 7 is a diagram showing a modified example of teaching in the second mode. Fig. 5 contrasts the appearance of the workpiece during teaching with the appearance of the workpiece after welding. The series of processes in Fig. 6 are executed mainly by processor 43 of robot control device 40 in cooperation with memory 42.

[0046] When teaching is performed, multiple welding line teaching identification marks Mks1, Mke1, Mks1, Mkm2, Mke2, Mks3, and Mke3 are fixedly positioned at the location or area to be welded on the workpiece Wk1. Specifically, as shown in FIG. 5 , a welding line teaching identification mark Mks1 for the welding start point and a welding line teaching identification mark Mke1 for the welding end point are positioned corresponding to the first welding line WB1 formed on the workpiece Wk2 after welding. Similarly, a welding line teaching identification mark Mks2 for the welding start point, a welding line teaching identification mark Mkm2 for the welding midpoint, and a welding line teaching identification mark Mke2 for the welding end point are positioned corresponding to the second welding line WB2 formed on the workpiece Wk2 after welding. Similarly, a welding line teaching identification mark Mks3 for the welding start point and a welding line teaching identification mark Mke3 for the welding end point are positioned corresponding to the third welding line WB3 formed on the workpiece Wk2 after welding. The material of the welding line teaching identification mark is not particularly limited, but if the workpiece Wk is a magnetic metal, it is preferable that the welding line teaching identification mark be a magnet.

[0047] After the welding line teaching identification marks have been placed at the appropriate locations on the workpiece Wk1, the robot control device 40 receives an instruction from the worker using an input device (not shown) to create a new program, and then generates a notification screen instructing the worker to attach the 3D mouse 10 and distance sensor 20, and outputs and displays the screen on the display 50 or teaching pendant 51. After this, the welding teaching method begins.

[0048] 6, processor 43 acquires relative position information of the tip of welding torch 33 with respect to distance sensor 20 (step St1). The relative position of the tip of welding torch 33 here refers to the linear distance from the position of distance sensor 20 to the tip of welding torch 33, and may be stored in advance as information in memory 42 and read out and acquired by processor 43, or may be acquired based on a signal transmitted from distance sensor 20. Processor 43 acquires relative position information of workpiece Wk (for example, workpiece Wk1 in FIG. 5) with respect to distance sensor 20 based on the signal transmitted from distance sensor 20 (step St2). The relative position of workpiece Wk here refers to the linear distance from the position of distance sensor 20 to workpiece Wk.

[0049] Processor 43 calculates the distance from the tip of welding torch 33 (i.e., the tip of welding wire 32) to workpiece Wk (i.e., the measured distance described above) based on the relative position information of the tip of welding torch 33 with respect to distance sensor 20 acquired in step St1 and the relative position information of workpiece Wk with respect to distance sensor 20 acquired in step St2 (step St3). Processor 43 determines whether the measured distance calculated in step St3 is less than 50 mm (step St4). This 50 mm is an example of a predetermined threshold for determining whether to select the first teaching mode or the second teaching mode. Note that 50 mm is merely an example of the predetermined threshold and is not limited to this value.

[0050] If processor 43 determines that the measured distance calculated in step St3 is 50 mm or more (step St4, NO), it selects the first teaching mode of the direct teaching method using 3D mouse 10 and writes the current position of welding torch 33 into a new welding program or stores it in memory 42 (step St5). Furthermore, processor 43 generates a notification screen that instructs to perform teaching using 3D mouse 10, and outputs and displays it on display 50 or teaching pendant 51 (step St5). After this, the processing of processor 43 returns to step St2.

[0051] On the other hand, if processor 43 determines that the measured distance calculated in step St3 is less than 50 mm (step St4, YES), it determines whether or not the position corresponding to the current position information of welding torch 33 constantly transmitted from welding robot 30 is a teaching point on the weld line (see FIG. 5 ) based on the signal transmitted from distance sensor 20 (step St6). If processor 43 determines that the current position of welding torch 33 is not a teaching point on the weld line (see FIG. 5 ) (step St6, NO), it selects the first teaching mode of the direct teaching method using 3D mouse 10 and writes the current position of welding torch 33 into a new welding program or stores it in memory 42 (step St7). Furthermore, processor 43 generates a notification screen WD2 (see FIG. 7 ) that instructs to perform teaching using 3D mouse 10, and outputs it to display on display device 50 or teaching pendant 51 (step St7). After this, the processing of processor 43 returns to step St2.

[0052] In step St7, even though it is determined that the measured distance is less than a predetermined threshold (e.g., 50 mm), the first teaching mode is selected. This may be the case when, as shown in FIG. 7, welding torch 33 first welds workpiece Wk3 and then moves along three linear paths (paths Pt1, Pt2, and Pt3) to weld workpiece Wk4. In other words, in this case, if welding torch 33 is close to workpiece Wk3 (measured distance < 50 mm), the second teaching mode is selected. Similarly, if welding torch 33 is close to workpiece Wk4 (measured distance < 50 mm), the second teaching mode is selected. However, if welding torch 33 is located in a position along the path Pt2, where it is moving from workpiece Wk3 to workpiece Wk4, the measured distance may be greater than or equal to a predetermined threshold (e.g., 50 mm). However, in the teaching of moving welding torch 33 from workpiece Wk3 to workpiece Wk4, there is no teaching point along the path. In other words, since there are no teaching points on path Pt2, high positional accuracy is not required for welding torch 33. Therefore, even if the measured distance of either workpiece Wk3 or Wk4 is less than a predetermined threshold (e.g., 50 mm), robot control device 40 selects the first teaching mode, considering that direct teaching using 3D mouse 10 is more efficient for moving welding torch 33.

[0053] On the other hand, if processor 43 determines that the current position of welding torch 33 is the teaching point of the welding line (see FIG. 5 ) (step St6, YES), it selects a second teaching mode using a touch sensor method that utilizes voltage fluctuations in welding wire 32 (step St8). Furthermore, processor 43 generates a notification screen instructing that teaching using the touch sensor method will be performed, and outputs and displays the notification screen on display 50 or teaching pendant 51 (step St8). If processor 43 detects a short-circuit signal related to the voltage of welding torch 33 using the touch sensor method, it writes the position of welding torch 33 at the time of detection into a new welding program or stores it in memory 42 (step St9). Thereafter, the processing of processor 43 returns to step St2 unless the new program is terminated (step St10, NO). If the new program is terminated (step St10, YES), the processing of processor 43 shown in FIG. 6 ends.

[0054] <About the technology of the present disclosure> As described above, the present disclosure discloses the following technical ideas.

[0055] (Item 1) a control device (robot control device 40) that selects either a first teaching mode or a second teaching mode as a teaching method for operating the welding robot during welding based on the distance between a welding torch (33) of the welding robot (30) and a workpiece (Wk) that is an object to be welded; and a display (50) that displays the results of the selection of the teaching method in a manner that allows a person to intuitively understand the results. Welding teaching system. This allows the welding teaching system to easily teach welding robot 30 (for example, an industrial robot) about welding while ensuring legal safety.

[0056] (Item 2) The first teaching mode is a mode in which the position of the welding torch is taught and stored using a 3D mouse (10), The second teaching mode is a mode in which the position of the welding torch is taught and stored based on a touch sensing method using a welding wire (32) connected to the welding torch. Item 1. The welding teaching system according to item 1. As a result, the welding teaching system can not only quickly acquire the position of the welding torch at the time of teaching using 3D mouse 10, which is intuitive and easy for the worker to operate, when the welding torch is far enough away from the workpiece, but also automatically acquire the position of the welding torch at the time of teaching using a touch sensor system when the welding torch is close to the workpiece. Therefore, the welding teaching system can adaptively acquire the position of the welding torch at the time of teaching according to the distance from the welding torch to the workpiece.

[0057] (Item 3) The control device If the distance is less than a predetermined threshold, selecting the second teaching mode; If the distance is equal to or greater than the predetermined threshold, the first teaching mode is selected. Item 1 or 2. The welding teaching system according to item 1 or 2. This allows the welding teaching system to easily determine either the first teaching mode or the second teaching mode based on a comparison between the distance (measured distance) from the welding torch to the workpiece and a predetermined threshold value.

[0058] (Item 4) the control device detects at least one of tilt, rotation, and three-dimensional movement of the welding torch based on an operation signal of the 3D mouse, and stores the position of the welding torch; Item 2. The welding teaching system according to item 2. This allows the welding teaching system to easily control the position or movement of the welding torch in response to various operations performed by the worker on the press-down portion of the 3D mouse 10.

[0059] (Item 5) The control device determining whether the teaching point by the welding torch is a position where a welding line is to be taught to the workpiece; When the teaching point is not a position at which the welding line is to be taught, a teaching recommendation in the first teaching mode is displayed on the display device regardless of the relationship between the distance and the predetermined threshold value. Item 2. The welding teaching system according to item 2. This allows the welding teaching system to efficiently acquire and store the position at the time of teaching by prioritizing whether or not high positional accuracy of the welding torch is required over the distance from the welding torch to the workpiece (measured distance).

[0060] (Item 6) The welding instruction system is implemented by a control device and a display device that are connected to the welding robot so that signals can be input and output between the control device and the welding robot, a step of selecting, by the control device, either a first teaching mode or a second teaching mode as a teaching method for operating the welding robot during welding, based on a distance between a welding torch of the welding robot and a workpiece that is an object to be welded; and presenting the selection result of the teaching method by the display device in a manner that allows a person to intuitively understand the selection result. Welding teaching method. As a result, according to the welding teaching method, welding robot 30 (for example, an industrial robot) can be easily taught welding while ensuring legal safety.

[0061] (Item 7) The control device is connected to the welding robot and the display device so that signals can be input and output therebetween, a step of selecting either a first teaching mode or a second teaching mode as a teaching method for operating the welding robot during welding based on a distance between a welding torch of the welding robot and a workpiece that is a welding object; and presenting the selection result of the teaching method on the display device so that the selection result can be intuitively understood by a person. Welding teaching control method. As a result, according to the welding teaching control method, welding robot 30 (for example, an industrial robot) can be easily taught welding while ensuring legal safety.

[0062] (Item 8) a control device which is a computer connected to the welding robot and the display so as to be able to input and output signals therebetween; a step of selecting either a first teaching mode or a second teaching mode as a teaching method for operating the welding robot during welding based on a distance between a welding torch of the welding robot and a workpiece that is a welding object; a step of displaying the selection result of the teaching method on the display device so that a person can intuitively grasp the selection result; Welding teaching control program. As a result, the welding teaching control program can easily teach welding robot 30 (for example, an industrial robot) about welding while ensuring legal safety.

[0063] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications, alterations, substitutions, additions, deletions, and equivalents within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure. Furthermore, the components of the various embodiments described above may be combined in any manner without departing from the spirit of the invention. [Industrial Applicability]

[0064] The present disclosure is useful as a welding teaching system, a welding teaching method, a welding teaching control method, and a welding teaching control program that easily teach a robot about welding while ensuring legal safety. [Explanation of symbols]

[0065] 10. 3D Mouse 20 Distance Sensor 30 Welding robot 31 Robot arm 32 Welding wire 33 Welding torch 40 Robot controller 41 Communication I / F 42 Memory 43 Processor 43a Sensor input section 43a1 Work position information 43b 3D mouse operation control section 43c Touch sensor control section 43d Teaching processing section 43d1 Object distance determination section 43d2 Optimal teaching determination section 43d3 Torch tip current position information 50 Display 51 Teaching pendant 100 Welding teaching system

Claims

1. a control device that selects either a first teaching mode or a second teaching mode as a teaching method for operating the welding robot during welding based on a distance between a welding torch of the welding robot and a workpiece that is a welding target; a display that displays the selection result of the teaching method in a manner that allows a person to intuitively understand the selection result; Welding teaching system.

2. The first teaching mode is a mode in which the position of the welding torch is taught and stored using a 3D mouse, the second teaching mode is a mode in which the position of the welding torch is taught and stored based on a touch sensing method using a welding wire connected to the welding torch; The welding teaching system according to claim 1 .

3. The control device If the distance is less than a predetermined threshold, selecting the second teaching mode; If the distance is equal to or greater than the predetermined threshold, the first teaching mode is selected. The welding teaching system according to claim 1 or 2.

4. the control device detects at least one of tilt, rotation, and three-dimensional movement of the welding torch based on an operation signal from the 3D mouse, and stores the position of the welding torch; The welding teaching system according to claim 2 .

5. The control device determining whether the teaching point by the welding torch is a position where a welding line is to be taught to the workpiece; When the teaching point is not a position at which the welding line is to be taught, a teaching recommendation in the first teaching mode is displayed on the display device regardless of the relationship between the distance and the predetermined threshold value. The welding teaching system according to claim 3 .

6. The welding instruction system is implemented by a control device and a display device that are connected to the welding robot so that signals can be input and output between the control device and the welding robot, a step of selecting, by the control device, either a first teaching mode or a second teaching mode as a teaching method for operating the welding robot during welding, based on a distance between a welding torch of the welding robot and a workpiece that is an object to be welded; and presenting the selection result of the teaching method by the display device in a manner that allows a person to intuitively understand the selection result. Welding teaching method.

7. The control device is connected to the welding robot and the display device so that signals can be input and output therebetween, a step of selecting either a first teaching mode or a second teaching mode as a teaching method for operating the welding robot during welding based on a distance between a welding torch of the welding robot and a workpiece that is a welding object; and presenting the selection result of the teaching method on the display device so that the selection result can be intuitively understood by a person. Welding teaching control method.

8. a control device which is a computer connected to the welding robot and the display so as to be able to input and output signals therebetween; a step of selecting either a first teaching mode or a second teaching mode as a teaching method for operating the welding robot during welding based on a distance between a welding torch of the welding robot and a workpiece that is a welding object; a step of displaying the selection result of the teaching method on the display device so that a person can intuitively grasp the selection result; Welding teaching control program.

Images