Remote control method for a remotely controlled welding system, and welding system

Abstract

To provide a remote control method of a remote control-type welding system that can appropriately perform various work, in performing manual operation to a remotely-installed welding robot, and a welding system.SOLUTION: A remotely controlling method of a welding system that can perform manual operation to a welding robot by remote control comprises: an obtaining step of obtaining image data on an arbitrary position using one or a plurality of photographing devices; a displaying step of displaying the image data using a display device; a receiving step of receiving an instruction to execute a contact sensing function by a welding torch to the welding robot, from a worker through an operation terminal; and an operating step of moving the welding torch on the basis of the instruction to the welding robot received through the operation terminal, during execution of the contact sensing function. In the operating step, when the contact sensing function senses contact of the welding torch with a member around the torch, a position of the welding torch is adjusted based on a position where the welding torch contacts the member.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a remote operation method for a remote operation type welding system and a welding system.

Background Art

[0002] Conventionally, as a prerequisite for automatically operating and working a multi-joint welding robot, an operator must manually teach positions, robot postures, welding conditions, etc. related to each operation such as welding operations, sensing operations, and idle running operations for moving to different work locations in advance. Also, when welding stops due to an error or the like during the automatic operation of the welding robot, the operator may manually perform correction work such as position adjustment.

[0003] Thus, when operating a welding robot system (hereinafter also referred to as a "welding system") equipped with a welding robot, there are cases where an operator needs to manually operate the welding robot (hereinafter also referred to as "manual operation"). On the other hand, depending on the welding environment, the operator may not be able to approach the vicinity of the robot. In such an environment, there is a problem that various operations cannot be appropriately performed in scenes where manual operation is required, such as teaching work and correction work during welding.

[0004] In response to the above problems, a technique such as Patent Document 1 is disclosed. In Patent Document 1, a technique is disclosed that enables an operator to remotely operate all teaching work and welding construction using a multi-joint welding robot even in an environment where a person cannot approach the side of the welding robot or stay there for a long time during the teaching work of welding, for example, in an environment such as inside a nuclear reactor of a nuclear power plant, and to obtain a sound welded part.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] As described in Patent Document 1, manual operation becomes possible even in environments where a person cannot approach the welding robot by remotely controlling it while checking image data captured using a CCD (Charge-Coupled Device) camera attached to the tip of the welding robot. However, in a welding environment, there is a limit to the number of visual sensors such as CCD cameras that can be installed, and blind spots may occur. For example, in order to achieve higher quality welding, it is sometimes necessary to manually perform very delicate tasks such as targeting and positioning in millimeter units at the groove of the workpiece (which may also be called the base material or the material to be welded). In Patent Document 1, there is only one visual sensor attached to the tip of the welding robot, resulting in many blind spots, making it difficult to perform various tasks properly. Also, depending on the posture and position of the welding robot, the area of ​​interest may be difficult to see from the image taken by the visual sensor, or depending on the performance of the visual sensor, the area of ​​interest may not be acquired with sufficient clarity. Furthermore, if the welding torch comes into contact with surrounding materials due to incorrect operation by the operator, damage to the welding robot may occur, such as torch breakage or wire bending.

[0007] Therefore, when manually operating a welding robot installed remotely, there is a need to provide functions that support such manual operation while preventing damage to the welding robot.

[0008] The present invention aims to provide a remote operation method and welding system for a remotely operated welding system that allows an operator to perform various tasks appropriately when manually operating a welding robot installed at a remote location. [Means for solving the problem]

[0009] To solve the above problems, the present invention has the following configuration. That is, a remote control method for a welding system that allows manual operation of a welding robot remotely, An acquisition step of acquiring image data at an arbitrary location using one or more imaging devices, A display step of displaying the image data using a display device, A receiving process in which instructions are received from the operator via an operating terminal to execute the contact detection function of the welding torch of the welding robot, During the execution of the contact detection function, the welding torch is moved based on instructions received by the welding robot via the operation terminal. It has, In the aforementioned operation step, if the contact detection function detects contact between the welding torch and a surrounding member, the position of the welding torch is adjusted based on the location of the contact.

[0010] Furthermore, the present invention has the following configuration as another embodiment. That is, A welding robot equipped with a welding torch, One or more imaging devices, Display device and An operating terminal for remotely manually operating the welding robot, A welding system comprising, An acquisition means for acquiring image data at an arbitrary position using one or more imaging devices, A display means for displaying the image data using the display device, A receiving means that receives instructions from the operator via the aforementioned operating terminal to execute the contact detection function using the welding torch, During the execution of the contact detection function, the operating means moves the welding torch based on instructions received by the welding robot via the operating terminal, It has, When the contact detection function detects that the welding torch is in contact with a surrounding member, the operating means adjusts the position of the welding torch based on the location of the contact. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide an assistance function when manually operating a welding system remotely.

Brief Description of the Drawings

[0012] [Figure 1] Schematic diagram showing an example of the system configuration according to an embodiment of the present invention. [Figure 2] Block diagram showing a configuration example of a robot control device according to an embodiment of the present invention. [Figure 3] Flowchart of sensing processing according to an embodiment of the present invention. [Figure 4A] Conceptual diagram for explaining a series of flows of a welding torch during remote operation according to an embodiment of the present invention. [Figure 4B] Conceptual diagram for explaining a series of flows of a welding torch during remote operation according to an embodiment of the present invention. [Figure 4C] Conceptual diagram for explaining a series of flows of a welding torch during remote operation according to an embodiment of the present invention. [Figure 4D] Conceptual diagram for explaining a series of flows of a welding torch during remote operation according to an embodiment of the present invention. [Figure 4E] T Conceptual diagram for explaining a series of flows of a welding torch during remote operation according to an embodiment of the present invention. [Figure 4F] Conceptual diagram for explaining a series of flows of a welding torch during remote operation according to an embodiment of the present invention. [Figure 4G] Conceptual diagram for explaining a series of flows of a welding torch during remote operation according to an embodiment of the present invention. [Figure 4H] Conceptual diagram for explaining a series of flows of a welding torch during remote operation according to an embodiment of the present invention. [Figure 4I] Conceptual diagram for explaining a series of flows of a welding torch during remote operation according to an embodiment of the present invention. [Figure 4J] Conceptual diagram for explaining a series of flows of a welding torch during remote operation according to an embodiment of the present invention. [Figure 4K] A conceptual diagram illustrating the sequence of operations of a welding torch during remote control according to one embodiment of the present invention. [Figure 4L] A conceptual diagram illustrating the sequence of operations of a welding torch during remote control according to one embodiment of the present invention. [Figure 5] A flowchart of the sensing process related to one embodiment of the present invention. [Figure 6] A flowchart of the adjustment process for a teaching program relating to one embodiment of the present invention. [Figure 7A] A conceptual diagram illustrating the adjustment process of a teaching program relating to one embodiment of the present invention. [Figure 7B] A conceptual diagram illustrating the adjustment process of a teaching program relating to one embodiment of the present invention. [Figure 7C] A conceptual diagram illustrating the adjustment process of a teaching program relating to one embodiment of the present invention. [Figure 8] Flowchart of the bevel sensing process according to one embodiment of the present invention. [Figure 9A] A conceptual diagram illustrating the groove sensing process when an error occurs in one embodiment of the present invention. [Figure 9B] A conceptual diagram illustrating the groove sensing process when an error occurs in one embodiment of the present invention. [Figure 9C] A conceptual diagram illustrating the groove sensing process when an error occurs in one embodiment of the present invention. [Modes for carrying out the invention]

[0013] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings and other documents. The embodiments described below are merely examples for illustrating the present invention and are not intended to be interpreted as limiting the invention. Furthermore, not all configurations described in each embodiment are necessarily essential for solving the problems of the present invention. In addition, in each drawing, the same components are given the same reference numeral to indicate their correspondence.

[0014] Furthermore, the remote control method and remote control welding robot system according to the present invention are useful not only for welding but also for additive manufacturing technology utilizing GMAW, specifically for Wire and Arc Additive Manufacturing (WAAM). While the term additive manufacturing is sometimes used in a broader sense as additive manufacturing or rapid prototyping, the present invention consistently uses the term additive manufacturing. When applying the method according to the present invention to additive manufacturing technology, "welding" can be replaced with "welding," "additive manufacturing," or "additive manufacturing." For example, when treated as welding, it would be "welding behavior," but when using the present invention as additive manufacturing, it can be replaced with "welding behavior." Similarly, when treated as welding, it would be "welding system," but when using the present invention as additive manufacturing, it can be replaced with "additive manufacturing system."

[0015] [Welding system configuration] Figure 1 shows an example of the configuration of a welding system 1 according to this embodiment. The welding system 1 shown in Figure 1 comprises a welding robot 10, a robot control device 20, a power supply device 30, a vision sensor 40, a data processing device 50, and a teaching pendant 60. When the method according to the present invention is applied to additive manufacturing, for example, the welding system 1 may be read as an additive manufacturing system, and the welding robot 10 as an additive manufacturing robot. In that case, further configurations may be included depending on the system to which it is applied.

[0016] The welding robot 10 shown in Figure 1 is composed of a 6-axis articulated robot, and a welding torch 11 for GMAW is attached to its tip. GMAW includes, for example, MIG (Metal Inert Gas) welding and MAG (Metal Active Gas) welding, and in this embodiment, MAG welding will be used as an example. Furthermore, the welding robot 10 is not limited to a 6-axis articulated robot; for example, a portable, small robot may be used.

[0017] The welding torch 11 is supplied with welding wire 13 from the wire feeder 12. The welding wire 13 is fed from the tip of the welding torch 11 toward the welding location. The power supply unit 30 supplies power to the welding wire 13. This power applies an arc voltage between the welding wire 13 and the workpiece W, generating an arc. The power supply unit 30 is equipped with a current sensor (not shown) for detecting the welding current flowing from the welding wire 13 to the workpiece W during welding, and a voltage sensor (not shown) for detecting the arc voltage between the welding wire 13 and the workpiece W.

[0018] The power supply unit 30 has a processing unit and a memory unit (not shown). The processing unit is composed of, for example, a CPU (Central Processing Unit). The memory unit is composed of, for example, volatile or non-volatile memory such as an HDD (Hard Disk Drive), ROM (Read Only Memory), or RAM (Random Access Memory). The processing unit controls the power applied to the welding wire 13 by executing a computer program for power control stored in the memory unit. The power supply unit 30 is also connected to the wire feeder 12, and the processing unit controls the feeding speed and amount of the welding wire 13.

[0019] The composition and type of welding wire 13 may be selected depending on the object to be welded. Examples of types of welding wire 13 include solid wire and flux-coated wire containing flux. Examples of materials for welding wire 13 include mild steel, stainless steel, aluminum, and titanium, and the wire surface may be plated with copper or the like. Furthermore, there are no particular limitations on the diameter of the welding wire 13. In this embodiment, as an example, a welding wire with an upper limit of 1.6 mm and a lower limit of 0.8 mm in diameter may be used.

[0020] The visual sensor 40 is composed of, for example, a CCD (Charge Coupled Device) camera. The placement of the visual sensor 40 is not particularly limited; it may be directly attached to the welding robot 10, or it may be fixed in a specific location in the surrounding area as a surveillance camera. When the visual sensor 40 is directly attached to the welding robot 10, the visual sensor 40 moves in accordance with the operation of the welding robot 10 to photograph the area around the tip of the welding torch 11. The number of cameras that make up the visual sensor 40 may be multiple. For example, the visual sensor 40 may be composed of multiple cameras with different functions and installation locations.

[0021] In this embodiment, a configuration using a fixed visual sensor 40 installed in the environment in which the welding robot 10 is used will be described as an example. If the visual sensor 40 is fixed to an area other than the welding robot 10, it is preferable to use a camera with at least PTZ functionality as the visual sensor 40, and pan, tilt, zoom, etc. may be controlled in accordance with the operation of the welding robot 10. The visual sensor 40 may acquire an image of the tip of the welding torch 11, which is the working position, in accordance with the operation of the welding robot 10. In addition, it may be configured so that, for example, an operator using the data processing device 50 can acquire an arbitrary image by specifying pan, tilt, zoom, etc., or instructing shooting settings in order to confirm the desired range. Specifically, it is preferable to acquire image data that includes at least one of the areas around the welding torch 11 of the welding robot or around the welding line. Examples of shooting settings include frame rate, number of pixels in the image, resolution, and shutter speed.

[0022] The data processing device 50 is composed of, for example, a CPU, ROM, RAM, hard disk drive, input / output interface, communication interface, video output interface, display unit (hereinafter also referred to as a display), etc. (not shown). The data processing device 50 may be composed of, for example, an information processing device such as a PC (Personal Computer). By the cooperation of the above-mentioned components, the data processing device 50 can display video data captured in real time at any frame rate by the visual sensor 40 on the display. Furthermore, if the visual sensor 40 is a fixed surveillance camera, as in this embodiment, the data processing device 50 may further include a visual sensor control unit. In addition, an image processing unit that can change the brightness, contrast, etc. of the displayed video data may be provided, or a storage unit that records and saves video may be provided. Note that the series of processes from image input to real-time image display on the display unit may be performed by software installed on the data processing device 50.

[0023] Each component of the welding system 1 is connected via various wired and wireless communication methods. The communication method is not limited to one; multiple communication methods may be combined for connection.

[0024] [Robot control system configuration] Figure 2 shows an example configuration of a robot control device 20 that controls the operation of a welding robot 10. The robot control device 20 consists of a CPU 201 that controls the entire device, a memory 202 that stores data, an operation panel 203 that includes multiple switches, a robot connection unit 204, and a communication unit 205. The memory 202 is composed of volatile or non-volatile storage devices such as ROM, RAM, or HDD. The memory 202 stores a control program 202A used to control the welding robot 10. The CPU 201 controls various operations of the welding robot 10 by executing the control program 202A.

[0025] Instructions for the robot control device 20 can be input using the operation panel 203 and the teaching pendant 60, with the teaching pendant 60 being the primary method of input. The teaching pendant 60 is connected to the main body of the robot control device 20 via the communication unit 205. The operator can input a teaching program using the teaching pendant 60. The robot control device 20 controls the welding robot 10 according to the teaching program input from the teaching pendant 60. The teaching program can also be automatically created using, for example, a computer (not shown) based on CAD (Computer-Aided Design) information. The actions defined in the teaching program are not particularly limited and may vary depending on the specifications of the welding robot 10 and the welding method.

[0026] Furthermore, the teaching pendant 60 allows the welding robot 10 to be manually operated via the robot control device 20. In this embodiment, a teaching playback type welding robot is applied. In this method, the operator manually operates the welding robot 10 and performs teaching tasks such as setting teaching points on the welding robot 10's movement line and welding line and storing their positions, storing coordinate information of the welding robot 10's posture, and inputting welding conditions. This creates a teaching program that is used when the welding robot 10 is operated automatically. In addition, if an error occurs during welding when the welding robot 10 is operating automatically and the welding robot 10 stops, the operator can use the teaching pendant 60 to manually operate the welding robot 10 and perform corrective tasks such as changing the target position.

[0027] The robot connection unit 204 is connected to the drive circuit of the welding robot 10. The CPU 201 outputs control signals based on the control program 202A to the drive circuit (not shown) of the welding robot 10 via the robot connection unit 204.

[0028] The communication unit 205 comprises a communication module for wired or wireless communication. The communication unit 205 is used for data and signal communication with the power supply unit 30, data processing unit 50, teaching pendant 60, etc. The communication method and standard used in the communication unit 205 are not particularly limited, and multiple methods may be combined, or they may differ for each connected device. The power supply unit 30 provides the CPU 201 via the communication unit 205, for example, the current value of the welding current detected by a current sensor (not shown) and the voltage value of the arc voltage detected by a voltage sensor (not shown).

[0029] The robot control device 20 controls the movement speed and protrusion direction of the welding torch 11 by controlling each axis of the welding robot 10. Furthermore, when performing a weaving motion, the robot control device 20 also controls the weaving motion of the welding robot 10 according to the set period, amplitude, and welding speed. Weaving motion refers to the alternating oscillation of the welding torch 11 in a direction intersecting the welding direction. Along with the weaving motion, the robot control device 20 performs welding line tracing control. Welding line tracing control is the operation of controlling the left and right position of the welding torch 11 with respect to the direction of travel so that a bead is formed along the welding line. The robot control device 20 also controls the feeding speed of the welding wire 13 by controlling the wire feeder 12 via the power supply device 30.

[0030] [Remote control method] In this embodiment, the explanation assumes that an operator using the welding system 1 controls and teaches a remotely located welding robot 10 using a teaching pendant 60 and a data processing device 50. In this case, the welding robot 10 and the vision sensor 40 are installed at a distance from the operator and the data processing device 50, i.e., remotely. The operator views images of the workpiece W placed around the welding robot 10, captured by the vision sensor 40, via the display unit of the data processing device 50. The operator then performs various operations while understanding the positional relationship between the welding robot 10, particularly the welding torch 11, and the workpiece W by confirming the images of the workpiece W.

[0031] In this case, the operator indirectly perceives the workpiece W and welding robot 10 using images acquired by the visual sensor 40. As described above, this can lead to blind spots in the image and situations where it is difficult to clearly perceive the target. In particular, fillet welding is difficult to perceive clearly, making it difficult for the operator to grasp the welding position in three dimensions. In groove welding, in addition to being difficult to perceive clearly, blind spots may also occur. Furthermore, delicate control is required for the contact between the tip of the welding robot 10 and the workpiece W. However, in situations where visibility is poor, it becomes difficult to make fine adjustments to the position of the welding torch 11 without applying excessive contact load to the tip. As a result, in order to avoid contact with the welding torch 11, an excessive distance is created between the workpiece W and the welding torch 11, making it impossible to teach the appropriate position of the welding torch 11.

[0032] Therefore, in this embodiment, contact between the welding robot 10 and the workpiece W is appropriately detected during remote operation, improving the convenience of the operator's teaching work.

[0033] Figure 3 is a flowchart showing the flow of how an operator determines the position on the workpiece W during remote operation. At this time, the robot control device 20 receives various operations from the operator via the teaching pendant 60 and performs processing.

[0034] In S301, the operator determines the current position of a predetermined part of the welding robot 10 from the image displayed on the data processing device 50. Here, the predetermined part is explained using the tip of the welding torch 11 as an example. The tip of the welding torch 11 here refers to the tip position of the welding wire 13 that is fed through the welding torch 11 and has a predetermined protrusion length. First, the robot control device 20 applies sensing power (hereinafter also referred to as "sensing voltage") to the welding torch 11 or the welding wire 13. Then, the robot control device 20 moves the welding torch 11 in a predetermined direction and brings it into contact with the workpiece W. Here, the predetermined direction is based on the operator's instruction to the teaching pendant 60. When the workpiece W and the welding wire 13 at the tip of the welding torch 11 come into contact, the operation of the welding robot 10 stops, and the positional relationship is determined from the position of the welding wire 13.

[0035] In S302, the operator moves the welding torch 11 away from the workpiece W. The distance and direction of this move may be based on the operator's instructions. Here, remote operation performed by the operator without applying sensing voltage is referred to as the "first remote operation," and remote operation performed by the operator with sensing voltage applied is referred to as the "second remote operation." The movement speed of the "first remote operation" is referred to as the "first movement speed," and the movement speed of the "second remote operation" is referred to as the "second movement speed." Therefore, the process in S301 is performed using the "second remote operation" based on the operator's instructions, and the process in S302 is performed using the "first remote operation" based on the operator's instructions.

[0036] The settings for the "first movement speed" and the "second movement speed" are each pre-defined with different speed levels. In this embodiment, the "first movement speed" can be selected from four pre-defined speed levels: "high," "medium," "medium-low," and "low." The "second movement speed" can be selected from a pre-defined range of "maximum speed" to "minimum speed," using a value between 100 and 1. The "high" setting for the "first movement speed" corresponds to 100 for the "second movement speed," and the "low" setting corresponds to 3. Unless the setting is changed, the "second movement speed" will be 3, which is the same speed as the "low" setting for the "first movement speed." It is preferable that the second movement speed be set slower than the first movement speed, and at least the second movement speed should be set to a speed that allows stopping almost simultaneously with detecting the voltage change that occurs when the welding torch 11 and the workpiece W come into contact. When a voltage change is detected, the robot control device 20 automatically switches to "first remote operation."

[0037] In S303, the operator, based on an arbitrary target position and the current position determined in S301, operates the welding robot 10 via the teaching pendant 60 using a first remote operation so that the tip of the welding torch 11 approaches the arbitrary target position.

[0038] In S304, the operator operates the teaching pendant 60 to stop the welding torch 11 at a position where the tip is a certain distance from the target position. At this point, the operator stops the first remote operation. The operator can arbitrarily determine this certain distance.

[0039] In S305, the operator uses the teaching pendant 60 to switch to the second remote operation and moves the welding torch 11 so that the tip of the torch contacts the workpiece W.

[0040] In S306, the robot control device 20 stops its operation with the tip of the welding torch 11 in contact with the workpiece W. At this time, the operator confirms that the welding torch 11 has stopped in contact with the workpiece W.

[0041] In S307, the operator determines whether the contact point of the tip of the welding torch 11 is within a predetermined range from the target position. This predetermined range can be arbitrarily determined by the operator as the range of tolerance. If the operator determines that the contact is not within the predetermined range (NO in S307), the operator's process returns to S302 and the process is repeated. If contact is made within the predetermined range (YES in S307), this process flow ends.

[0042] Next, we will describe an example of the operation of the welding torch 11 in remote operation to which the above sensing processing is applied. Figures 4A to 4L are diagrams illustrating the flow of a series of operations of the welding torch 11 performed by instructions from the operator via the teaching pendant 60 during remote operation according to this embodiment. Figures 4A to 4L show the positional relationship between the workpiece W and the welding torch 11, respectively, when viewed along the z-axis and when viewed along the x-axis. We will explain in detail using Figures 4A to 4L, following the flowchart shown in Figure 3. Here, we will explain using an example of a workpiece W in which two members are arranged orthogonally as shown in Figure 4A.

[0043] Figure 4B shows an example of the state before the start of process S301 in Figure 3. First, as shown in Figure 4C, the operator instructs the robot control device 20 via the teaching pendant 60 to determine the current position of the welding torch 11, and then brings the welding torch 11 into contact with the workpiece W using a second remote operation. This corresponds to the process S301 in Figure 3. Here, an example of moving the welding torch 11 along the y-axis is shown, but the configuration may be such that it is moved along other axes.

[0044] Next, as shown in Figure 4D, after the tip of the welding torch 11 makes contact with the workpiece W, the sensing voltage is released and the system switches to the first remote operation. Subsequently, the operator moves the welding torch 11 away from the workpiece W. This corresponds to step S302 in Figure 3. The direction of retraction here is shown in Figure 4C as an example of the opposite direction to the direction in which it approached the workpiece W.

[0045] Next, as shown in Figure 4E, the operator moves the welding torch 11 in the direction approaching the target position via the teaching pendant 60, while maintaining the first remote control. This corresponds to step S303 in Figure 3.

[0046] Next, as shown in Figure 4F, after moving the welding torch 11 a predetermined distance, the operator switches to a second remote operation via the teaching pendant 60 to move the tip of the welding torch 11 so that it contacts the workpiece W. This corresponds to step S305 in Figure 3. At this point, if the contact position between the workpiece W and the welding torch 11 is not within a predetermined range from the target position (corresponding to NO in S307 of Figure 3), the process is repeated.

[0047] Figure 4G corresponds to the repeated process S302. Figure 4H corresponds to the repeated process S303. Furthermore, Figure 4I corresponds to the repeated process S306. At this point, it is determined that the coordinates of the x and y axes coincide with the target position. On the other hand, the z axis is not included within a predetermined range from the target position (corresponding to NO in S307 in Figure 3), and the process is repeated further.

[0048] Figure 4J corresponds to the further repeated process S302. Next, Figure 4K corresponds to the further repeated process S303. Here, since the x and y axis positions have already been adjusted, the operator moves the welding torch 11 closer to the target position in the unadjusted direction, i.e., along the z-axis in this example, via the teaching pendant 60. At this time, the operator has previously switched to the second remote control to move the welding torch 11 in the unadjusted direction.

[0049] Then, as shown in Figure 4L, when the tip of the welding torch 11 comes into contact with the vicinity of the target position, the remote adjustment operation by the operator is completed.

[0050] If the visual sensor 40 is positioned to photograph the workpiece W from the front of the welding line, for example, in the state shown in Figure 4C or Figure 4F, the position of the welding torch 11 and the target position may overlap in the image from the visual sensor 40, making it difficult for the operator to see the target position. Furthermore, depending on the performance of the visual sensor 40, such as its resolution, it may not be possible to clearly photograph the target position on the workpiece W, which would also make it difficult for the operator to see the target position. As a result, it may become difficult for the operator to specify an appropriate target position when creating a teaching program. Therefore, by having the welding system 1 perform the above-described control when identifying the position on the workpiece W, it becomes possible to provide a support function for creating a more accurate teaching program.

[0051] Figure 5 is a flowchart showing the processing flow performed by the robot control device 20 when the operator of welding system 1 initiates a "second remote operation" using the teaching pendant 60. In other words, this flowchart is executed by the robot control device 20 when the operator of welding system 1 uses the teaching pendant 60 to perform an operation to detect contact between the workpiece W and the tip of the welding torch 11. Therefore, this flowchart may be executed in each of the processes such as S301, S305, and S306 shown in Figure 3.

[0052] Furthermore, as described above, during remote operation, images of the area around the welding torch 11 are acquired by the visual sensor 40 and displayed as appropriate on the display unit of the data processing device 50 so that the operator can see them. The shooting settings of the visual sensor 40 may be adjusted arbitrarily by the operator, for example.

[0053] In S501, when the operator starts the "second remote operation" using the teaching pendant 60, the robot control device 20 applies a sensing voltage to the tip of the welding torch 11 to detect contact based on instructions from the teaching pendant 60. In this embodiment, the second remote operation uses a touch sensor method, applying a voltage between the workpiece W and the welding wire 13 at the tip of the welding torch 11, and utilizing the voltage drop phenomenon that occurs when the welding wire 13 contacts the workpiece W. This allows for the detection of the workpiece position, groove, and position. The contact detection function is not limited to this, and a pressure sensor that detects contact by the pressure generated when the welding torch and the base material come into contact, or a voltage detection sensor that detects contact by the load voltage applied to the motor when the welding torch and the base material come into contact, may also be used. When the operator starts the contact detection function on the teaching pendant 60, the sensing voltage may continue to be applied between the welding wire and at least one of the nozzles constituting the welding torch and the workpiece until the contact detection function is terminated or the welding torch and the base material come into contact once.

[0054] In S502, the robot control device 20 sets the movement speed of the welding torch 11, i.e., the speed of the second remote control, to the second movement speed.

[0055] In S503, the robot control device 20 displays on the display unit (not shown) of the teaching pendant 60 that it is a second remote operation, that is, that sensing is in progress. The method of display here is not particularly limited, but for example, it may be configured to change the color of the icon displayed on the display unit or to display a message.

[0056] In S504, the robot control device 20 displays on the display unit (not shown) of the teaching pendant 60 that the sensing operation is being performed at a low speed, i.e., a second movement speed. The method of display here is not particularly limited, but for example, an icon may be displayed in association with the icon displayed in S503.

[0057] In S505, the robot control device 20 determines whether the sensing voltage applied to the welding torch 11 has been turned OFF. In other words, it determines whether the welding torch 11 and the workpiece W are in contact at the start of the sensing operation. If they are in contact, the sensing voltage is turned OFF at this point. If the sensing voltage is turned OFF (YES in S505), the robot control device 20 stops applying the sensing voltage, and the robot control device 20 proceeds to S513. On the other hand, if the sensing voltage is ON (NO in S505), the robot control device 20 proceeds to S506.

[0058] In S506, the robot control device 20 starts moving the welding torch 11 in response to receiving remote control from the operator via the teaching pendant 60.

[0059] In S507, the robot control device 20 determines whether it has received a sensing release instruction from the operator via the teaching pendant 60 during the sensing operation. The sensing release instruction may be given, for example, by releasing any button on the teaching pendant 60. If the sensing release instruction is received (YES in S507), the robot control device 20 proceeds to S511. On the other hand, if the sensing release instruction is not received (NO in S507), the sensing operation continues, and the robot control device 20 proceeds to S508.

[0060] In S508, the robot control device 20 determines whether the sensing voltage applied to the welding torch 11 has turned OFF. In other words, it determines whether the welding torch 11 and the workpiece W have come into contact. If they have come into contact, the sensing voltage turns OFF at this point. If the sensing voltage is OFF (YES in S508), the robot control device 20 proceeds to S509. On the other hand, if the sensing voltage is ON (NO in S508), the sensing operation continues, and the robot control device 20 returns to S507.

[0061] In S509, the robot control device 20 determines whether the welding wire 13 at the tip of the welding torch 11 has come into contact with the workpiece W. In this embodiment, the robot control device 20 determines whether the welding wire 13 at the tip of the welding torch 11 has come into contact with the workpiece W, or whether the workpiece W has come into contact with a location other than the welding wire 13, by utilizing the fact that different signal terminals detect a drop in the sensing voltage depending on the location of contact. If it is determined that the welding wire 13 and the workpiece W have come into contact (YES in S509), the robot control device 20 proceeds to S512. On the other hand, if it is determined that the welding wire 13 and the workpiece W have not come into contact (NO in S509), it means that the workpiece W has come into contact with an unexpected location on the welding torch 11, so the robot control device 20 proceeds to S510 to issue a warning. In this embodiment, the state in which the sensing voltage is OFF and the welding wire 13 and the workpiece W are not in contact is assumed to be when the nozzle portion of the welding torch 11 comes into contact with the workpiece W. Even if the nozzle part makes contact, the sensing voltage drops, making it possible to detect the contact. For example, this can be used as a means to prevent damage to the torch.

[0062] In S510, the robot control device 20 displays a warning message on the display unit of the teaching pendant 60. The content of the warning message is not particularly limited, but for example, it may notify that the workpiece W is in contact with a part other than the tip of the welding torch 11.

[0063] In step S511, the robot control device 20 turns off the sensing voltage.

[0064] At S512, the robot control device 20 stops its operation based on remote control.

[0065] In S513, the robot control device 20 displays an indication on an unillustrated display unit of the teaching pendant 60 that sensing is not in progress. This display may be performed by restoring the display made in S503.

[0066] In S514, the robot control device 20 sets the movement speed of the welding torch 11 to the first movement speed, "low". Then, this processing flow is terminated.

[0067] As described above, the processing flow shown in Figure 5 is executed from start to finish each time an instruction to start the "second remote operation" is received from the operator via the teaching pendant 60. Therefore, it is executable in each step shown in Figure 3.

[0068] As described above, this embodiment makes it possible to provide functions to support manual operation of a welding robot installed remotely, while preventing damage to the welding robot.

[0069] [Example 1] This section describes a modified version of the remote control support function shown in the above embodiment, applied when adjusting or updating the content of a manually generated teaching program. Here, the teaching point specified in the teaching program is used as the target position on the workpiece W. The welding robot 10 and the vision sensor 40 are installed remotely, away from the operator and the data processing device 50. The operator views the image of the workpiece W placed around the welding robot 10, captured by the vision sensor 40, via the display unit of the data processing device 50. While viewing the image of the workpiece W, the operator adjusts the parameters of the teaching program by operating the teaching pendant 60.

[0070] For example, pre-generated teaching programs are often used generically in various welding systems. However, in such cases, mechanical errors and deviations in workpiece placement may occur depending on the welding system, requiring adjustment of the teaching program parameters in that environment. In such cases, the support functions according to the embodiment described above can be used to facilitate parameter adjustment via remote control.

[0071] Figure 6 shows a flowchart illustrating the adjustment process for the position parameters of the teaching program in this example. Here, we will explain an example in which the position of the groove of the workpiece W is detected and the teaching position is adjusted.

[0072] In S601, the robot control device 20 acquires the teaching program. This acquisition may be performed by reading an already generated teaching program from a location specified by the operator. Alternatively, it may acquire a teaching program that the operator has directly entered.

[0073] In S602, the robot control device 20 moves the welding torch 11 to the first teaching point of the welding section specified in the teaching program generated in S601.

[0074] In S603, the operator switches modes via the teaching pendant 60. The mode here corresponds to a dedicated processing mode applied when adjusting or updating the contents of the manually generated teaching program described above. At this time, the robot control device 20 may notify the operator that the mode has been switched via the display unit of the teaching pendant 60.

[0075] In S604, the robot control device 20 receives an operation to perform groove position sensing (hereinafter referred to as groove sensing) via the teaching pendant 60. Based on the received operation, the robot control device 20 starts groove sensing. In this process, sensing operations based on the groove shape are performed automatically based on instructions from the operator via the teaching pendant 60. However, the sensing operations based on the groove shape may also be operated by the operator. The robot control device 20 attempts to move the tip of the welding torch 11 to the center of the groove while detecting contact with the periphery of the groove. The movement to the center of the groove here may be automatically controlled by moving the welding torch 11 based on a predetermined movement pattern and approaching the center position according to the contact situation.

[0076] In S605, the operator determines whether the groove sensing was successful. Successful groove sensing here means that the tip of the welding torch 11 is positioned at the center of the groove at the teaching point currently under focus. The tip of the welding torch 11 here refers to the tip position of the welding wire that is fed through the welding torch 11 and has a predetermined protrusion length. If the groove sensing is successful (YES in S605), the operator proceeds to S606. On the other hand, if the groove sensing operation is unsuccessful, that is, if the operator determines that the robot tip is not at the center of the groove at the teaching point under focus, or if the operator determines during groove sensing that it is not possible to align the robot tip with the center of the groove even if the series of groove sensing operations based on the groove shape is continued to the end (NO in S605), the operator proceeds to S608.

[0077] In S606, the operator updates the center position of the target groove as the taught position via the teaching pendant 60. The operator's process then proceeds to S607.

[0078] In S607, the operator determines whether there are any unprocessed teaching points in the teaching program generated in S601 for the section to be welded. If there are unprocessed teaching points (YES in S607), the process proceeds to S610. If there are no unprocessed teaching points (NO in S607), the process flow ends. At this point, the mode switched in S603 may be automatically returned to the previous mode, or the mode may be maintained until instructions are received from the operator.

[0079] In S608, the operator, via the teaching pendant 60, uses the first remote operation to retract the tip of the welding torch 11 from the groove. The operator then proceeds to S609.

[0080] In S609, the operator uses the first remote operation to bring the tip of the welding torch 11 closer to the groove. This movement may be based on instructions from the operator via the teaching pendant 60, or it may be set according to the position and shape of the groove detected up to this point. The operator then returns to S604 and repeats the groove sensing operation for the teaching point currently under focus.

[0081] At S610, the operator retracts the tip of the welding torch 11 via a first remote operation using the teaching pendant 60.

[0082] In S611, the operator moves the tip of the welding torch 11 to the vicinity of the next unprocessed teaching point via the teaching pendant 60 using a first remote operation. The operator's process then returns to S604 and is repeated.

[0083] The explanation will be given in detail using Figures 7A to 7C, following the flowchart shown in Figure 6. Here, we will explain using an example of a workpiece W in which a groove is provided between two members, as shown in Figure 7A, and a backing material is placed on the back side of the groove.

[0084] In the example shown in Figure 7A, the teaching program sets a start point P1 and an end point P5 for a certain welding section, and specifies three teaching points P2 to P4 between them. The teaching points P2 to P4 have different values ​​from the actual welding points P2' to P4' that should be welded. Therefore, the teaching program is required to set the values ​​of teaching points P2 to P4 to be the same as or approximately the same as the welding points P2' to P4'. Note that the welding points P2' to P4' correspond to the center position of the groove.

[0085] First, as shown in Figure 7B, the welding robot 10 focuses on teaching point P2 as the initial teaching point. This corresponds to step S602 in Figure 6. Then, the operator performs the process according to the flow up to step S606, and as shown in Figure 7C, when the center of the groove is identified at the position of welding point P2', the operator gives an instruction to update the parameters of the teaching program, especially the position parameter, and updates the teaching program. The teaching program is updated by performing the same operation for teaching points P3 and P4.

[0086] In summary, this example demonstrates how to assist in adjusting the parameters of a teaching program. As a result, it becomes possible to achieve more precise welding.

[0087] [Differentiation 2] A modified example of using the remote control support function described in the above embodiment to adjust the tip position of the welding torch 11 when an error occurs during welding will be described below.

[0088] For example, if an error occurs during welding, it is necessary to remotely move the welding torch 11 to a position where welding can be resumed. In this case, by using the sensing process according to the above embodiment, it is possible to easily adjust the position of the welding torch 11 so that it does not come into contact with or be positioned in an inappropriate location on the workpiece.

[0089] Figure 8 shows a flowchart illustrating the adjustment process for the position of the welding torch 11 during welding in this example. Here, we will explain using an example where the position of the groove of the workpiece W is detected and the welding torch 11 is positioned in the center of the groove. Assume that welding has been performed before the start of the process flow in Figure 8, and that some error has occurred during the welding process, causing it to stop. In this case, this process flow will start.

[0090] In step S801, the robot control device 20 moves the tip of the welding torch 11 away from the workpiece. The tip of the welding torch 11 refers to the tip position of the welding wire that is fed through the welding torch 11 and has a predetermined protrusion length. The direction of movement here may be predetermined or may be set according to the welding performed so far and the shape of the workpiece.

[0091] In S802, the operator, using the teaching pendant 60, brings the tip of the welding torch 11 closer to the groove using the first remote operation.

[0092] In S803, the robot control device 20 switches modes based on instructions from the operator via the teaching pendant 60. The mode here corresponds to the mode used when performing the remote sensing operation described above. At this time, the operator may be notified that the mode has been switched via the display unit of the teaching pendant 60.

[0093] In S804, the operator senses the inside of the groove via a second remote operation using the teaching pendant 60. The operator attempts to move the tip of the welding torch 11 to the center of the groove while detecting contact with the periphery of the groove. This movement to the center of the groove may be automatically controlled by moving the welding torch 11 based on a predetermined movement pattern, and adjusting it to approach the center depending on the contact situation.

[0094] In S805, the operator determines whether the groove sensing operation was successful. Here, success in the groove sensing operation means that the operator determines that the tip of the welding torch 11 is positioned in the center of the groove. If the groove sensing operation is successful (YES in S805), the operator proceeds to S807. On the other hand, if the groove sensing operation is unsuccessful (NO in S805), the operator moves the tip of the welding torch 11 away from the groove, and the operator returns to S804, repeating the process until the tip is positioned in the center of the groove.

[0095] In S806, the operator instructs the robot control device 20 to resume welding based on the identified position. The robot control device 20 then switches the mode that was switched in S803 back to the welding mode.

[0096] In S807, the operator, via the teaching pendant 60, retracts the tip of the welding torch 11 from the groove using a first remote operation. The operator then proceeds to S808.

[0097] In S808, the operator uses the first remote control to bring the tip of the welding torch 11 closer to the groove. This movement may be based on instructions from the operator via the teaching pendant 60, or it may be set according to the position and shape of the groove detected up to this point. The operator then returns to S804 and repeats the groove sensing operation for the teaching point currently under focus.

[0098] We will explain this in detail using Figures 9A to 9C, following the flowchart shown in Figure 8. Here, we will explain using an example of a workpiece W in which a groove is provided between two members, as shown in Figure 8A, and a backing material is placed on the back side of the groove.

[0099] In the example shown in Figure 9A, a teaching program sets a start point P1 and an end point P4 for a certain welding section, and specifies two welding points P2 and P3 between them. The welding robot 10 will perform welding on the section from welding point P2 to P3 based on this teaching program.

[0100] Then, as shown in Figure 9B, an error occurs during welding when the welding torch 11 and the workpiece W come into contact, causing the welding to stop. In this case, the processing flow shown in Figure 8 is initiated. As a result of the processing in Figure 8, the welding torch 11 is positioned in the center of the groove as shown in Figure 9C, and welding resumes.

[0101] As demonstrated in this example, even if welding is interrupted due to an error, the position of the welding torch 11 can be adjusted using the remote control support function described above, thereby providing appropriate support for the operator's welding operation.

[0102] <Other Embodiments> In the above embodiment, when performing the sensing operation, contact with the workpiece W was detected by moving the welding torch 11 itself, and the positional relationship was determined. However, the configuration is not limited to this, and for example, the positional relationship between the welding torch 11 and the workpiece W may be determined by adjusting the feed speed of the welding wire 13 protruding from the welding torch 11 and detecting contact between the fed-out welding wire 13 and the workpiece W. This configuration can be used, for example, when it is known that the workpiece W is located in the direction in which the welding wire 13 protrudes.

[0103] Furthermore, the above embodiment illustrates an example of how the robot control device 20 controls the welding torch 11 based on remote control performed by the operator via the teaching pendant 60. Here, the main body of the processing in each step included in the above processing flow is not necessarily limited to the above configuration. For example, some of the operations shown above as being based on individual instructions from the operator may be performed automatically by the welding system 1.

[0104] In the present invention, the functions of one or more embodiments described above can also be realized by supplying a program or application to a system or device using a network or storage medium, and having one or more processors in the computer of that system or device read and execute the program.

[0105] Alternatively, it may be implemented by a circuit that performs one or more functions. Examples of circuits that perform one or more functions include ASICs (Application Specific Integrated Circuits) and FPGAs (Field Programmable Gate Arrays).

[0106] As described above, the following matters are disclosed in this specification: (1) A remote control method for a welding system that allows manual operation of a welding robot remotely, An acquisition step of acquiring image data at an arbitrary location using one or more imaging devices, A display step of displaying the image data using a display device, A receiving process in which instructions are received from the operator via an operating terminal to execute the contact detection function of the welding torch of the welding robot, During the execution of the contact detection function, the welding torch is moved based on instructions received by the welding robot via the operation terminal. It has, In the aforementioned operation step, if the contact detection function detects contact between the welding torch and a surrounding member, the position of the welding torch is adjusted based on the location of the contact. A method for remotely controlling a welding system. This configuration allows operators to perform various tasks appropriately when manually controlling a welding robot installed remotely.

[0107] (2) The system further includes an update step for receiving instructions to update the parameters of the teaching program used in the welding system, The remote operation method for a welding system according to (1), wherein in the update step, the method receives an instruction to update a position parameter specified in the teaching program based on the position of contact detected by the contact detection function. This configuration allows for precise position adjustment of the welding robot even when operated remotely, and enables adjustment of the parameters of the teaching program to the appropriate position.

[0108] (3) A remote operation method for a welding system according to (1) or (2), wherein, in the operation step, while the contact detection function is being performed, at least one of the moving speed of the welding torch or the feeding speed of the welding wire from the welding torch is set to a predetermined first speed. This configuration makes it possible to detect contact with the workpiece during remote operation using the feed rate of the welding torch or welding wire.

[0109] (4) The remote operation method for a welding system according to (3), wherein the first speed is slower than the second speed when the contact detection function is not being performed. With this configuration, while the contact detection function is running, the detection speed is slowed down, allowing for immediate control stoppage in the event of contact, thus enabling more precise control.

[0110] (5) A remote operation method for a welding system according to any one of (1) to (4), wherein the contact detection function is detected based on a change in voltage, load, or motor load that occurs when contact occurs. This configuration allows for contact detection by applying various contact detection functions based on principles such as voltage, load, or changes in motor load.

[0111] (6) A remote operation method for a welding system according to any one of (1) to (5), wherein the operator is notified via the operation terminal or the display device that the contact detection function is being performed while it is being performed. This configuration allows operators to easily recognize when the contact detection function is running, thereby improving ease of operation.

[0112] (7) A remote control method for a welding system according to any one of (1) to (6), wherein the one or more imaging devices change their imaging position in accordance with the movement of the welding torch. This configuration allows the shooting position to change as the welding torch moves, thereby improving the operability of remote operation by the operator.

[0113] (8) A welding robot equipped with a welding torch, One or more imaging devices, Display device and An operating terminal for remotely manually operating the welding robot, A welding system comprising, An acquisition means for acquiring image data at an arbitrary position using one or more imaging devices, A display means for displaying the image data using the display device, A receiving means that receives instructions from the operator via the aforementioned operating terminal to execute the contact detection function using the welding torch, During the execution of the contact detection function, the operating means moves the welding torch based on instructions received by the welding robot via the operating terminal, It has, The operating means is a welding system that, when the contact detection function detects contact between the welding torch and a surrounding member, adjusts the position of the welding torch based on the location of the contact. This configuration allows operators to perform various tasks appropriately when manually controlling a welding robot installed remotely. [Explanation of symbols]

[0114] 1. Welding System 10 Welding robots 11 Welding Torch 12 Wire feeder 13 Welding wire 20 Robot control devices 201 CPU 202 memory 202A Control Program 203 Control Panel 204 Robot connection section 205 Communications Department 30 Power supply 40 Vision Sensors 50 Data Processing Devices 60 Instructional Pendant Double job

Claims

1. A remote control method for a welding system that allows manual operation of a welding robot remotely, An acquisition step of acquiring image data at an arbitrary location using one or more imaging devices, A display step of displaying the image data using a display device, A receiving process in which instructions are received from the operator via an operating terminal to execute the contact detection function of the welding torch of the welding robot, During the execution of the contact detection function, the welding torch is moved based on instructions received by the welding robot via the operation terminal. It has, When the remote operation performed by the worker when the contact detection function is not being executed is referred to as the first remote operation, and the remote operation performed by the worker when the contact detection function is being executed is referred to as the second remote operation, In the above operation step, In the first remote operation described above, at least one of the moving speed of the welding torch or the feeding speed of the welding wire from the welding torch is set to a predetermined first speed, In the second remote operation, the speed is set to a second speed that is slower than the first speed. The welding robot is operated by the first remote control so that the welding torch approaches the target position. The operator switches to the second remote operation and moves the welding torch so that the tip of the welding torch contacts the surrounding material. When the contact detection function detects that the welding torch has come into contact with the surrounding material, the contact detection function terminates, and the position of the welding torch is adjusted based on the location of the contact. A method for remotely controlling a welding system.

2. The system further includes an update step for receiving instructions to update the parameters of the teaching program used in the welding system, The remote operation method for a welding system according to claim 1, wherein in the update step, the system receives an instruction to update a position parameter specified in the teaching program based on the position of contact detected by the contact detection function.

3. The remote control method for a welding system according to claim 1 or 2, wherein the contact detection function is detected based on a change in voltage, load, or motor load that occurs when contact occurs.

4. The remote operation method for a welding system according to claim 1 or 2, wherein while the contact detection function is being performed, the operator is notified via the operation terminal or the display device that the function is being performed.

5. The remote control method for a welding system according to claim 1 or 2, wherein the one or more imaging devices change their imaging position in accordance with the movement of the welding torch.

6. A welding robot equipped with a welding torch, One or more imaging devices, Display device and An operating terminal for remotely manually operating the welding robot, A welding system comprising, An acquisition means for acquiring image data at an arbitrary position using one or more imaging devices, A display means for displaying the image data using the display device, A receiving means that receives instructions from the operator via the aforementioned operating terminal to execute the contact detection function using the welding torch, During the execution of the contact detection function, the operating means moves the welding torch based on instructions received by the welding robot via the operating terminal, It has, When the remote operation performed by the worker when the contact detection function is not being executed is referred to as the first remote operation, and the remote operation performed by the worker when the contact detection function is being executed is referred to as the second remote operation, In the aforementioned operating means, In the first remote operation described above, at least one of the moving speed of the welding torch or the feeding speed of the welding wire from the welding torch is set to a predetermined first speed. In the second remote operation, the speed is set to a second speed that is slower than the first speed. The welding robot is operated by the first remote control so that the welding torch approaches the target position. A welding system comprising: when the operator switches to the second remote operation, the tip of the welding torch is moved so that it contacts a surrounding member, and the contact detection function detects that the welding torch has come into contact with a surrounding member, the contact detection function is terminated, and the position of the welding torch is adjusted based on the position of the contact.

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