Control method for welding robot, control device, welding system, and program

Abstract

A control method, control device, welding system, and program for a welding robot are proposed. Measurement and position correction are performed more efficiently using a laser sensor, and the efficiency of welding work is improved. The control method has: a determination process that determines setting information for setting a reference position including measurement by the laser sensor in a control program for the welding robot; a measurement process that performs measurement of a welding object using the laser sensor based on the control program based on the setting information; a determination process that determines whether or not the measurement in the measurement process is successful; a calculation process that, in the case where it is determined in the determination process that the measurement is successful, calculates a correction amount for a control parameter for the welding robot based on the reference position and a measurement result in the measurement process; and a retry process that, in the case where it is determined by the determination process that the measurement is unsuccessful, retries the measurement of the measurement process.

Description

Technical Field

[0001] This invention relates to a control method, control device, welding system, and program for a welding robot equipped with a laser sensor. Background Technology

[0002] Previously, welding robots were used to prepare the components to be welded (hereinafter referred to as workpieces) at predetermined positions for welding. Even when welding the same type of workpiece, positional shifts could occur for each workpiece, or the workpiece's bevel precision could vary, resulting in subtle differences in bevel shape for each workpiece. Therefore, when using welding robots, the control program needed to be corrected before welding. For example, this might involve using laser sensors or similar devices to measure the workpiece, detecting positional shifts and changes in bevel shape, and then correcting the control program based on these detection results.

[0003] For example, Patent Document 1 discloses a position detection system for an automatic welding machine that, based on distance measurement data obtained through a search operation, can confirm the image analysis results on a teach pendant when different image processing parameters are applied, without performing subsequent search operations. This position detection system can shorten the image processing adjustment time during system import or new teaching.

[0004] Prior art literature

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2008-221281

[0007] Welding involves a variety of construction conditions. For example, complex bevel shapes, workpiece gloss, and temporary foreign matter attachments are all significant factors that reduce sensing accuracy. Patent Document 1 addresses the issue of eliminating the repetitive work required to sense each workpiece and explore optimal image parameters to address these critical factors. However, when using laser sensors, measurement errors sometimes occur due to these aforementioned factors. Handling these errors requires operator intervention, leading to reduced welding efficiency.

[0008] Patent Document 1 does not consider measurement errors of the laser sensor. Furthermore, Patent Document 1 only discloses the display of image analysis results for operator verification, completely neglecting to consider whether position corrections can be automatically and efficiently reflected in the welding robot's control program. In other words, from the viewpoint of improving welding operation efficiency, a method is sought that aims to efficiently automate the process from laser-sensor-based position correction to welding, minimizing operator intervention for resuming work when measurement errors occur. Summary of the Invention

[0009] The present invention addresses the aforementioned issues and aims to provide a control method, control device, welding system, and program for a welding robot that can perform measurement and position correction more efficiently using a laser sensor.

[0010] To address the aforementioned issues, the present invention has the following structure: A control method for a welding robot is proposed, wherein the welding robot is equipped with a laser sensor.

[0011] The control method for the welding robot is characterized by having:

[0012] The process is determined by setting information in the control program of the welding robot, including setting the reference position measured by the laser sensor.

[0013] In the measurement process, the laser sensor is used to measure the welding object through the control program based on the set information.

[0014] The determination process determines whether the measurement in the measurement process was successful.

[0015] In the calculation process, if the measurement is determined to be successful in the determination process, based on the reference position and the measurement results in the measurement process, a correction amount for the control parameters of the welding robot is calculated; and

[0016] The retry process involves retrying the measurement process if the determination process determines that the measurement has failed.

[0017] Furthermore, as another aspect of the present invention, it has the following structure. That is, a control device for a welding robot is proposed, wherein the welding robot is equipped with a laser sensor.

[0018] The control device of the welding robot is characterized by having:

[0019] The decision unit determines the setting information in the control program of the welding robot, including the setting of the reference position measured by the laser sensor;

[0020] The measurement unit uses the laser sensor to measure the welding object through the control program based on the set information.

[0021] The determination unit determines whether the measurement performed by the laser sensor is successful.

[0022] The calculation unit, upon the determination unit determining that the measurement is successful, calculates a correction amount for the control parameters of the welding robot based on the reference position and the measurement results of the laser sensor; and

[0023] The retry unit retryes the measurement performed by the laser sensor if the determination unit determines that the measurement has failed.

[0024] Furthermore, as another aspect of the present invention, it has the following structure. That is, a welding system incorporating a laser sensor, a welding robot, and a control device is proposed, characterized in that...

[0025] The control device has:

[0026] The decision unit determines the setting information in the control program of the welding robot, including the setting of the reference position measured by the laser sensor;

[0027] The measurement unit uses the laser sensor to measure the welding object through the control program based on the set information.

[0028] The determination unit determines whether the measurement performed by the laser sensor is successful.

[0029] The calculation unit, upon the determination unit determining that the measurement is successful, calculates a correction amount for the control parameters of the welding robot based on the reference position and the measurement results of the laser sensor; and

[0030] The retry unit retryes the measurement performed by the laser sensor if the determination unit determines that the measurement has failed.

[0031] Furthermore, as another aspect of the present invention, it has the following structure. That is, a program is proposed for causing a computer to perform the following steps:

[0032] The process is determined by setting information in the control program of a welding robot equipped with a laser sensor, including setting the reference position measured by the laser sensor.

[0033] In the measurement process, the laser sensor is used to measure the welding object through the control program based on the set information.

[0034] The determination process determines whether the measurement in the measurement process was successful.

[0035] In the calculation process, if the measurement is determined to be successful in the determination process, based on the reference position and the measurement results in the measurement process, a correction amount for the control parameters of the welding robot is calculated; and

[0036] The retry process involves retrying the measurement process if the determination process determines that the measurement has failed.

[0037] Invention Effects

[0038] According to the present invention, laser sensors can be used to perform measurement and position correction more efficiently, thereby improving the efficiency of welding operations. Attached Figure Description

[0039] Figure 1 This is a schematic diagram illustrating a structural example of a welding system according to an embodiment of the present invention.

[0040] Figure 2 This is an explanatory diagram illustrating the measurement range of the laser sensor involved in the embodiments of the present invention.

[0041] Figure 3 This is a schematic diagram illustrating a structural example of a robot control device according to an embodiment of the present invention.

[0042] Figure 4A This is an explanatory diagram illustrating the measurement of a laser sensor according to an embodiment of the present invention.

[0043] Figure 4B This is a diagram illustrating a structural example of a display screen showing measurement results according to an embodiment of the present invention.

[0044] Figure 5A This is a flowchart of the measurement process according to one embodiment of the present invention.

[0045] Figure 5B This is a flowchart of a measurement process based on manual operation according to an embodiment of the present invention.

[0046] Figure 6 This is an explanatory diagram illustrating a structural example of a teaching program according to an embodiment of the present invention.

[0047] Figure 7 This is an explanatory diagram illustrating an example of an operation based on a teaching program according to an embodiment of the present invention.

[0048] Figure 8 This is an explanatory diagram illustrating the measurement start position during a retry of a measurement according to an embodiment of the present invention.

[0049] Figure 9A This is an illustrative diagram used to explain the situation of false detections in the measurement of a laser sensor.

[0050] Figure 9BThis is an illustrative diagram used to explain the situation of false detections in the measurement of a laser sensor.

[0051] Figure 9C This is an explanatory diagram used to illustrate the correction process for false detections in the measurement of laser sensors.

[0052] Figure 9D This is an explanatory diagram used to illustrate the correction process for false detections in the measurement of laser sensors.

[0053] Figure 10A This is an illustrative diagram used to explain the situation of false detections in the measurement of a laser sensor.

[0054] Figure 10B This is an illustrative diagram used to explain the situation of false detections in the measurement of a laser sensor.

[0055] Figure 10C This is an illustrative diagram used to explain the situation of false detections in the measurement of a laser sensor.

[0056] Figure 10D This is an explanatory diagram used to illustrate the correction process for false detections in the measurement of laser sensors.

[0057] Figure 11 This is a graph showing an example of the detection results of a laser sensor when the correction process for false detections is taken into account.

[0058] Symbol Explanation

[0059] 1 Welding System

[0060] 10 Welding Robots

[0061] 11 Welding torch

[0062] 12 Welding wire feeding device

[0063] 13 Welding wire

[0064] 20 Robot control device

[0065] 30 Power supply unit

[0066] 40 Laser Sensors

[0067] 50 teach pendants

[0068] 201 CPU (Central Processing Unit)

[0069] 202 Memory

[0070] 202A Control Procedure

[0071] 203 Control Panel

[0072] 205 Robot Connection Section

[0073] 206 Ministry of Communications. Detailed Implementation

[0074] Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. Furthermore, the embodiments described below are merely illustrative of one embodiment of the present invention and are not intended to limit or explain the invention. Moreover, all structures described in each embodiment are not limited to those necessary to solve the problems of the present invention. In addition, in the accompanying drawings, the same structural elements are indicated by the same reference numerals.

[0075] Furthermore, the method for measuring the welding behavior involved in this invention is useful not only in welding but also in additive manufacturing techniques that effectively utilize Gas-shielded Metal Arc Welding (GMAW), specifically in Wire and Arc Additive Manufacturing (WAAM). Additionally, while the term "additive manufacturing" is sometimes used broadly in the context of Wire and Arc Additive Manufacturing or rapid prototyping, the term is used consistently in this invention. When applying the method involved in this invention to additive manufacturing techniques, "welding" is referred to as "deposition," "additive manufacturing," or "deposition," etc. For example, when treated as welding, it is called "welding behavior," but when this invention is effectively utilized as additive manufacturing, it is referred to as "deposition behavior," or when treated as welding, it is called "welding system," but when this invention is effectively utilized as additive manufacturing, it can be referred to as "additive manufacturing system."

[0076] <First Implementation Method>

[0077] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0078] [Structure of the welding system]

[0079] Figure 1 This illustrates a structural example of the welding system 1 described in this embodiment. Figure 1The welding system 1 shown is configured to include a welding robot 10, a robot control device 20, a power supply device 30, a laser sensor 40, and a teach pendant 50 (hereinafter also referred to as a teaching pendant). Furthermore, when the method according to the present invention is applied to additive manufacturing, for example, the welding system 1 may be referred to as an additive manufacturing system, and the welding robot 10 may be referred to as an additive manufacturing robot.

[0080] Figure 1 The welding robot 10 shown is a 6-axis articulated robot with a GMAW welding torch 11 mounted on its front end. GMAW includes, for example, MIG (Metal Inert Gas) welding and MAG (Metal Active Gas) welding; in this embodiment, MAG welding will be described as an example. Furthermore, the welding robot 10 is not limited to a 6-axis articulated robot; for example, a small, mobile robot may also be used.

[0081] Welding wire 13 is supplied from the welding wire feed device 12 to the welding torch 11. The welding wire 13 is fed from the tip of the welding torch 11 to the welding area. The power supply device 30 supplies power to the welding wire 13. With this power, an arc voltage is applied between the welding wire 13 and the workpiece W, generating an arc. The power supply device 30 is equipped with a current sensor (not shown) for detecting the welding current flowing from the welding wire 13 to the workpiece W, and a voltage sensor (not shown) for detecting the arc voltage between the welding wire 13 and the workpiece W.

[0082] The power supply unit 30 has a processing unit and a storage unit (not shown). The processing unit includes, for example, a CPU (Central Processing Unit). The storage unit includes, 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 storage unit. The power supply unit 30 is also connected to the welding wire feed device 12, and the processing unit controls the feed speed and feed amount of the welding wire 13. The power supply unit 30 is also connected to the workpiece W side to detect the current and voltage during welding.

[0083] The composition and type of welding wire 13 can be varied depending on the object being welded. Examples of types of welding wire 13 include solid core welding wire and flux-containing welding wire. Furthermore, examples of materials for welding wire 13 include mild steel, stainless steel, aluminum, and titanium; copper plating can also be applied to the surface of the welding wire. Moreover, there are no particular limitations on the diameter of the welding wire 13. In this embodiment, as an example, a welding wire with a diameter ranging from 0.8 mm to 1.6 mm can be used.

[0084] The laser sensor 40 can be, for example, a two-dimensional or higher laser displacement meter utilizing an optical cutting method. In this case, the laser sensor 40 includes: an irradiation unit that irradiates a strip of laser light onto the surface of an object; and a light-receiving unit that receives changes in the reflected light using a CMOS (Complementary MOS) sensor. The configuration of the laser sensor 40 is not particularly limited; for example, it can be directly mounted on the welding robot 10 or held and used in place of the welding torch 11. Furthermore, multiple laser sensors 40 can be used.

[0085] Figure 2 This diagram illustrates the measurement range of the laser sensor 40 according to this embodiment, showing an example where it is positioned near the welding torch 11. In this configuration, the welding torch 11 and the laser sensor 40 move as a single unit. The irradiation direction of the laser from the laser sensor 40 is set to be approximately parallel to the direction in which the welding torch 11 supplies the welding wire 13. Figure 2 In this diagram, Ld represents the area that cannot be measured along the direction of laser irradiation. La represents the area that can be measured along the direction of laser irradiation, i.e., the measurement distance. Wa represents the area that can be measured in a direction orthogonal to the direction of laser irradiation, i.e., the measurement width. For example, it can be set to La = 350mm, Ld = 192mm, and Wa = 111mm.

[0086] A laser sensor 40 is placed near the welding torch 11 to irradiate a strip of laser with a measurement width of Wa = 111 mm. This sensor measures the object before welding, i.e., the workpiece W, detecting the bevel position, gap width, and bevel shape. Based on the detection data, correction information for the reference position can be output as described later, or the measurement data for the gap width can be used to capture the contour position, oscillation correction amount, etc.

[0087] The various components constituting the welding system 1 can be communicatively connected via various wired / wireless communication methods. The communication method is not limited to one; multiple communication methods can be combined for connection.

[0088] [Structure of the robot control device]

[0089] Figure 3This describes a structural example of a robot control device 20 that controls the actions of the welding robot 10 according to this embodiment. The robot control device 20 is configured to include a CPU 201 (the overall control device), a memory 202 for storing data, an operation panel 203 including multiple switches, a robot connection unit 205, and a communication unit 206. The memory 202 is configured as a volatile or non-volatile storage device such as ROM, RAM, or HDD. A control program 202A for controlling the welding robot 10 is stored in the memory 202. The CPU 201 reads and executes the control program 202A to control various actions of the welding robot 10 and utilizes the measurement function of the laser sensor 40. Furthermore, the control program 202A includes teaching programs corresponding to various actions of the welding robot 10 and individual welding operations. It is preferable from the viewpoint of control efficiency to further separate the teaching program corresponding to individual welding operations into a measurement program (hereinafter also referred to as a sensing program), a program for various actions of the welding robot 10, and a program for welding operations (hereinafter also referred to as a welding program). In this case, the sensing program and the welding program can be configured in a way that establishes an association between them. Regarding examples of teaching procedures corresponding to the individual welding involved in this embodiment, using Figure 6 To be described later.

[0090] The teach pendant 50 is primarily used for inputting instructions to the robot control device 20. The teach pendant 50 is connected to the main body of the robot control device 20 via a communication unit 206. The operator can use the teach pendant 50 to input a teaching program. The robot control device 20 controls the welding actions of the welding robot 10 according to the teaching program input from the teach pendant 50. Alternatively, the teaching program can be automatically created using a computer (not shown) based on CAD (Computer-Aided Design) information. The actions defined by the teaching program are not particularly limited and can vary depending on the specifications of the welding robot 10, welding method, etc. The teach pendant 50 has an operation unit and display unit (not shown) different from the operation panel 203, and can be used for example... Figure 4B The following will show the display screen.

[0091] A drive circuit (not shown) of the welding robot 10 is connected to the robot connection section 205. 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 section 205, thereby causing the welding robot 10 to move.

[0092] Communication unit 206 is a communication module for wired or wireless communication. Communication unit 206 is used for data communication with power supply unit 30, laser sensor 40, and teach pendant 50, etc. The communication method and specifications used in communication unit 206 are not particularly limited, and multiple methods can be combined. Power supply unit 30 transmits, via communication unit 206, current values ​​detected by a current sensor (not shown) and arc voltage values ​​detected by a voltage sensor (not shown) to CPU 201. Furthermore, the values ​​detected by the current sensor and voltage sensor (not shown) can also be used as feedback information within power supply unit 30.

[0093] The robot control device 20 controls the movement speed of the welding torch 11 and the target direction of the welding torch (which can also be referred to as the wire feed direction) by controlling each axis of the welding robot 10. Furthermore, the robot control device 20 controls the oscillating motion of the welding robot 10 according to the set period, amplitude, and welding speed. The oscillating motion refers to the alternating shaking of the welding torch 11 in a direction intersecting the welding direction. The robot control device 20 performs welding line contour control together with the oscillating motion. Welding line contour control refers to the action of controlling the left and right position relative to the welding torch 11's direction of travel in a way that forms a weld bead along the welding line. In addition, the robot control device 20 controls the wire feed device 12 via the power supply device 30, and also controls the feed speed of the welding wire 13.

[0094] (Screenshot displayed)

[0095] use Figure 4A as well as Figure 4B An example of the structure of the display screen shown by the teach pendant 50 will be explained. Figure 4A This illustrates an example of a measurement performed by irradiating a workpiece 401, which is the object of welding, with a laser 402 through a laser sensor 40. Here, an example is shown where the workpiece 401 is positioned at the left and right sides of the image, and the bevel 400, serving as the root gap, is located at the center of the image.

[0096] Figure 4B express Figure 4AThe diagram shows an example of the structure of a display screen 410 representing the measurement results of a welded object. Display screen 410 includes three display areas 411, 412, and 413. Display area 411 displays a summary of the displayed content. In this example, display screen 410 displays a message indicating that the measurement results are being shown. Display area 412 displays the measurement results in the form of a graph. Furthermore, the measurement results can be displayed in mass width. Mass width refers to the approximate shape of the bevel; specifically, the approximate shape of the bevel is displayed in the form of a graph. Here, the horizontal axis corresponds to the width direction in the measurement process, and the vertical axis corresponds to the height direction in the measurement process. The unit of measurement is shown as [mm], but this can vary depending on the size of the object being measured. Figure 4A As shown, since bevel 400 is located in the center of the measured object, the height detected at its corresponding position is lower than that at other positions. Display area 413 shows detailed information about the measurement results. For example, information parsed based on the measurement results can also be displayed. Here, information such as bevel shape, measurement success or failure, bevel center coordinates, and gap width is displayed.

[0097] As for the bevel shape, it can detect shapes such as serrated bevels, V-grooves, flared bevels, and T-joint bevels. Successful measurement indicates successful measurement processing. The bevel center coordinates represent the position of the bevel center relative to the origin of the coordinate system (hereinafter referred to as the laser coordinate system) set by the laser sensor 40. The gap width can be the width of the bottom of the bevel, the width of the top, or the width of the center position in the height direction of the bevel. Other information can also be further displayed in the display area 413, and the displayed items and content can be switched based on the operator's operation and settings. Furthermore, while an example of a screen structure showing the measurement results of the laser sensor 40 is shown here, different screens during welding can also be displayed on the display section of the teach pendant 50.

[0098] Furthermore, in the processing described later, if an error occurs during measurement, the error content can be displayed in display area 411, prompting the operator to confirm. Additionally, if an error occurs midway through measurement, the measurement results up to the midway point can be displayed in display area 412. Furthermore, when an error occurs, a method similar to... Figure 4B The display screen 410 shown has different structures.

[0099] In addition, the measurement results of the laser sensor 40 are stored in a storage unit such as the memory 202 in a timely manner. At this time, the bevel shape can be determined based on the measurement results, and this information can be stored and managed in correspondence with the measurement results. Furthermore, the correspondence between the measurement results and the bevel shape can be defined as a pattern, which can be used when determining the bevel shape based on the actual measurement results.

[0100] [Processing Sequence]

[0101] Figure 5A This is a flowchart of the process involved in this embodiment. Figure 5A The processing flow shown is performed before welding begins to measure the object to be welded using the laser sensor 40. This processing flow can be implemented by reading and executing the teaching program included in the control program 202A stored in the memory 202 by the CPU 201 of the robot control device 20. Furthermore, at the start of this processing flow, the workpiece W, which is the object to be welded, is placed in the welding position.

[0102] In S501, CPU201 reads the sensing program from the teaching program and performs measurement of workpiece W based on laser sensor 40. During the measurement by laser sensor 40, data such as the center coordinates of the bevel, the gap width, and feature points used for shape recognition are obtained. Furthermore, the data obtained here is based on a laser coordinate system defined by laser sensor 40, which defines three-dimensional coordinate axes and its origin.

[0103] In S502, CPU201 determines whether the measurement in S501 was successful. The success or failure determination can be based on factors such as whether the center position of the bevel was detected, whether all processes defined by the sensing program were executed, or whether an anomaly was detected. The criteria for success or failure are predetermined. If the measurement is successful ("Yes" in S502), CPU201's processing proceeds to S503. Conversely, if the measurement fails ("No" in S502), CPU201's processing proceeds to S513.

[0104] In step S503, CPU201 determines whether a reference position command exists in the sensing program. A reference position command is a command used to set a reference position for measurement when performing measurements based on the sensing program. If a reference position command exists ("Yes" in S503), CPU201's processing proceeds to S504. Conversely, if no reference position command exists ("No" in S503), this processing flow ends. Without a reference position command, the process becomes one where the welding program is not modified based on the measurement results.

[0105] In S504, CPU201 determines whether a reference position setting parameter exists in the reference position command of the sensing program. The reference position setting represents the coordinate value of the reference position when the laser sensor 40 performs its measurement operation. In this embodiment, the reference position is set using the laser coordinate system in the laser sensor 40. If a reference position setting exists ("Yes" in S504), CPU201's processing proceeds to S508. Conversely, if no reference position setting exists ("No" in S504), CPU201's processing proceeds to S505.

[0106] In S505, CPU201 determines whether it is in teach mode. In this embodiment, teach mode refers to a mode that can automatically set appropriate settings on the welding system side without setting various settings. Here, the teach mode provides the function of automatically setting the coordinates of the measured reference position on the welding system side. The settings of various modes can be preset by the operator. If it is in teach mode ("Yes" in S505), the processing of CPU201 proceeds to S506. If it is not in teach mode ("No" in S505), this processing flow ends.

[0107] In S506, CPU201 automatically determines the reference position based on given rules. In this embodiment, the center position of the bevel obtained by the measurement performed by laser sensor 40 in S501 is determined as the coordinates of the reference position.

[0108] In step S507, CPU201 rewrites the parameters of the reference position command using the reference position determined in S506. That is, the reference position determined in S506 is set as the reference position used in the welding program. Then, the processing of CPU201 proceeds to S508.

[0109] In S508, CPU201 calculates a correction amount based on the difference between the set value of the reference position set in the welding program and the measured value obtained by the laser sensor 40 in S501. At this time, both the set value and the measured value are represented by values ​​in the laser coordinate system. At this time, if the measurement result of the laser sensor 40 includes measurement error, a pre-defined correction coefficient can be used for further correction.

[0110] In S509, CPU201 converts the correction values ​​obtained in S508 from the laser coordinate system to values ​​in the robot coordinate system used in the welding robot 10. For example... Figure 2As shown, the coordinate systems used as references differ depending on the configuration of the laser sensor 40 relative to the welding torch 11. Therefore, using the origin of the predetermined robot coordinate system as a reference, an offset from the origin of the laser coordinate system is preset, and this offset is used to perform the transformation from the laser coordinate system to the robot coordinate system.

[0111] In step S510, CPU 201 stores the data converted in step S509 in memory 202.

[0112] In S511, CPU 201 determines whether the value of the data converted in S509 is within the range of a threshold. The threshold used here is predetermined and held by memory 202. If the data is within the threshold range ("Yes" in S511), CPU 201 terminates this processing flow. In this case, it means that the measurement performed by laser sensor 40 is proceeding normally, and the measurement process ends appropriately. If the data is outside the threshold range ("No" in S511), CPU 201's processing proceeds to S512.

[0113] In S512, CPU201 issues an error indicating that the data obtained as a result of the measurement process is inappropriate. Here, CPU201 can notify the operator by displaying the error on the display screen of the teach pendant 50. Then, the processing of CPU201 proceeds to S516.

[0114] In S513, CPU201 determines whether the number of retries for a measurement failure has reached the upper limit. The upper limit for the number of retries is predetermined by the sensing program, etc. Furthermore, the number of retries is managed using a counter (not shown). If the number of retries reaches the upper limit ("Yes" in S513), CPU201's processing proceeds to S515. On the other hand, if the number of retries has not reached the upper limit ("No" in S513), CPU201's processing proceeds to S514.

[0115] In S514, CPU201 sets up settings for retrying measurements by laser sensor 40. These settings may include, for example, adjusting the start position of the measurement to a position different from the previous measurement. The adjustments are not particularly limited, but can be changed based on the reasons for the previous measurement failure. An example of the settings is provided using... Figure 8 This will be described later. Furthermore, CPU 201 can perform an operation to increment the value of the counter used to manage the number of retries mentioned above (increment). Then, the processing of CPU 201 returns to S501, where the measurement of laser sensor 40 is retried using the setting value set in S514.

[0116] In S515, CPU201 issues an error indicating that the maximum number of retries for the measurement performed by laser sensor 40 has been reached. Here, CPU201 can notify the operator by displaying the error on the display screen of the teach pendant 50. Then, CPU201's processing proceeds to S516.

[0117] In S516, CPU201 performs measurement processing based on manual operator actions. For details regarding this process, please refer to... Figure 5B This will be described later. The processing in S516 is equivalent to processing the result of the measurement processing based on the sensing program on the welding system 1 side, which results in a status that requires operator confirmation. After the processing in S516, the processing in CPU 201 proceeds to S503 to continue processing.

[0118] exist Figure 5A In the processing sequence shown, if the result of the judgment process in S511 is that the exported data is outside the range of a given threshold, a data error is issued and the system switches to measurement based on manual operation. However, this structure is not limited to this one; it could also be as follows: if the number of retries for measurement has not reached the upper limit, the system proceeds to step S514, where automatic measurement based on the laser sensor 40 is performed again after setting the retry time.

[0119] (Measurement processing based on manual operation)

[0120] Figure 5B It is used for explanation Figure 5A A flowchart detailing the process of S516.

[0121] In S521, CPU201 receives a retry instruction for measurement via the operator of welding system 1. This process is... Figure 5A In the processing described herein, the process begins after the operator is notified of the error. Therefore, the operator removes elements that could have caused the error from the workpiece W, which is the object of welding. Examples of the operator's tasks include checking the surface condition of the workpiece W, grinding, and removing foreign objects. Furthermore, the specific tasks performed by the operator are not particularly limited and vary depending on the welding conditions and the condition of the workpiece W. Additionally, a retry instruction can be received via the teach pendant 50, at which point a retry setting can also be accepted.

[0122] In S522, CPU201, based on the retry instruction received in S521, moves the laser sensor 40 towards the measurement start position. This movement can either retract the position of the laser sensor 40 to remeasure the position where the error occurred, or it can move it to measure from a new start position.

[0123] In step S523, CPU201 performs measurements on laser sensor 40. The measurement process can be related to... Figure 5A The measurements are the same as those of the S501.

[0124] In S524, CPU201 determines whether the measurement performed by laser sensor 40 in S524 was successful. This determination can be made using... Figure 5A The determination criteria in S502 are the same as those in S502, but different determination criteria can also be used. If the measurement is successful ("Yes" in S524), the processing of CPU201 proceeds to S525. On the other hand, if the measurement fails ("No" in S524), the processing of CPU201 proceeds to S526.

[0125] In S525, CPU 201 switches from manual measurement control to automatic measurement control based on a sensing program. At this time, CPU 201 can display on the teach pendant 50 an indication that the measurement performed manually was successful, and an indication that the switch to automatic measurement control is in progress. Then, this processing flow ends. If this processing flow ends, the processing of CPU 201 proceeds to... Figure 5A S503.

[0126] In S526, CPU201 issues an error indicating that the measurement of laser sensor 40 has failed. At this time, CPU201 uses teach pendant 50 along with the error message to prompt a reconfirmation of the state of workpiece W. Then, after the operator removes the elements that caused the measurement failure again, a retry instruction for measurement is received in S521, thereby repeatedly performing measurement processing based on manual operation.

[0127] [Program Structure]

[0128] Figure 6 This illustrates an example of the structure of the teaching program used during welding according to this embodiment. The teaching program here is preset by the operator or others and maintained as part of the control program 202A. Furthermore, the structure of the teaching program shown here is an example and is not limited to this. Depending on the shape, structure, etc., of the object being welded, more commands and tasks may be used.

[0129] The teaching program involved in this embodiment includes a sensing program 600 and a soldering program 610. The sensing program 600 is in... Figure 5A , Figure 5B The process shown is used in the welding procedure 610. The welding procedure 610 is based on the processing results of the sensing procedure 600 and is used during the actual welding process.

[0130] exist Figure 6In the example of the sensing program 600 shown, it consists of four commands: 601 to 604. Command 602 is related to... Figure 5A This corresponds to the reference position command used in the S503 processing. Furthermore, in command 602, the reference position is set... Figure 5A The reference position setting parameter 602a is used in the S504 processing. Here, as the reference position setting parameter 602a, the values ​​of the three-dimensional coordinate system of the laser coordinate system are set to X=a, Y=b, Z=c. Furthermore, in command 602, the task "No1" for obtaining the bevel gap width or obtaining the correction amount is specified. The tasks for performing such actions and the identification information such as "No1" are predefined and included as part of the control program 202A. By specifying the identification information using the arguments of each command included in the sensing program 600, the task corresponding to the identification information can be executed. "V001" and "C001" represent the destination for saving the processing result of the specified task. In this example, "V001" represents the destination for saving the correction amount, and "C001" represents the destination for saving the gap width. In addition, if the value of parameter 602a is not set, Figure 5A The S504 process determines "No".

[0131] The welding procedure 610 in this example includes five commands: 611 to 615. Command 611a specifies the correction of welding operation parameters using the correction amount obtained from command 602 of sensing procedure 600. That is, the welding position and welding conditions of welding procedure 610 are corrected based on the correction amount measured and calculated by sensing procedure 600. Command 612 specifies the reading of welding conditions related to welding along with linear movement. At this time, different welding conditions can be read based on the correction amount calculated by sensing procedure 600 and the measurement results. Furthermore, command 614a specifies the release of the correction amount applied in command 611a. By releasing the correction amount, welding procedure 610 can be universally processed to be used for various welding methods.

[0132] Figure 7 It is used for based on Figure 6 The diagrams shown illustrate the various procedures used to depict the movement of the welding torch 11 around the workpiece. In this example, as... Figure 2 As shown, the laser sensor 40 is positioned near the welding torch 11 and performs roughly the same operation. Figure 7 The “P” shown corresponds to Figure 6 The commands included in each program. Figure 7The image shows left and right workpieces 701 as the objects of welding, a bevel 700 formed between the workpieces 701, and a backing plate 702 for the workpieces 701. In this example, the bevel 700 shows a shape that extends with the direction of welding. Figure 7 An example of a bevel gradually widening as the depth direction advances.

[0133] Figure 7 The numbers “P1” to “P9” shown correspond to Figure 6 The teaching procedure shown includes the following commands. “P1” to “P4” correspond to commands 601 to 604 that constitute the sensing procedure 600, respectively, indicating the position during measurement. In addition, “P5” to “P9” correspond to commands 611 to 615 that constitute the welding procedure 610, respectively, indicating the position during welding.

[0134] First, the measurement process based on sensing program 600 will be explained. According to command 601, the position of welding torch 11 is... Figure 7 The welding torch 11 is then moved linearly from position "P1" to position "P2" via command 602. Furthermore, the reference positions are set to X=a, Y=b, Z=c, initiating task "No.1". As described above, task "No.1" is based on measurements from the laser sensor 40.

[0135] By command 603, the welding torch 11 moves linearly from position "P2" to position "P3". In other words, the laser sensor 40 measures the distance from position "P2" to position "P3". The measurement ends when the position "P3" is reached. Then, the program specified by command 603 is read out. The program read out here is, for example, a welding condition setting program for determining and setting the welding conditions used during the execution of welding program 610 based on the measurement results. In this embodiment, multiple sets of parameters for various control items are predefined as welding conditions. Then, the welding conditions suitable for welding are determined from multiple welding conditions based on the measurement results. By command 604, the welding torch 11 moves linearly from position "P2" to position "P3". Figure 7 Move in a straight line to the position indicated by "P4". In this example, "P1" and "P4" are represented by the same position, but they can also be different.

[0136] Next, the operation based on welding procedure 610 will be explained. By command 611, welding torch 11 moves in a straight line to the position indicated by "P5". In this example, "P1" and "P5" are represented by the same position, but they could be different. Furthermore, the correction amount detected by command 602 of sensing procedure 600 is reflected in the control parameters.

[0137] By command 612, the welding torch 11 moves in a straight line to the position indicated by "P6," which becomes the welding start position. In this example, "P2" and "P6" are shown at the same position, but considering the correction amount, "P6" becomes a different position based on the correction amount. Then, the welding conditions set by command 603 of the sensing program 600 are read out. As described above, the welding conditions read out here can be changed according to the measurement results of the sensing program 600. Then, the arc is turned on, and welding begins.

[0138] Command 613 moves the welding torch 11 in a straight line to position "P7". That is, welding is performed from position "P6" to position "P7". Command 614 moves the welding torch 11 in a straight line to position "P8". That is, welding is further performed from position "P7" to position "P8". Alternatively, as with commands 613 and 614, a structure can be established where different commands are used to control welding lengths exceeding a given threshold within a single command. Furthermore, in... Figure 7 In the example, the size of the bevel gap width varies, so welding conditions can be switched during welding of "P6" to "P7" and welding of "P7" to "P8". Afterwards, the arc is disconnected, ending the welding. Then, the correction amount reflected by command 611 is released. By command 615, the welding torch 11 is "moved linearly" to the position indicated by "P9". The position indicated by "P9" is not particularly limited; for example, it can be the same as "P1" which is the starting position of the action, or it can be a position based on the starting position of the next welding action. Furthermore, during the welding interval from arc connection to arc disconnection, an arc sensor can be used to automatically correct the welding torch position. Additionally, an arc sensor refers to a structure that uses welding current, etc., to detect the position of the bevel and can follow it during welding, ensuring that welding can be performed without the welding torch deviating from the bevel even if the workpiece shifts, deviates, or thermal strain occurs during welding.

[0139] (Position control during measurement retest)

[0140] Figure 8 This is a diagram illustrating the measurement start position during a retry of the measurement of laser sensor 40. Figure 5A In the processing, if the measurement by the laser sensor 40 fails, a retry setting is performed in step S514. When a measurement fails, the probability of failure is high if the measurement is attempted again from the same starting position as the previous measurement. Therefore, in this embodiment, the starting position of the measurement is changed during the retry.

[0141] exist Figure 8In the diagram, the horizontal axis represents position, and measurements are performed from left to right. Position 801 indicates the starting position of the last measurement. Position 802 indicates the position where the measurement based on the laser sensor 40 was determined to have failed. In the event of a measurement failure based on the laser sensor 40, a position corresponding to a predetermined displacement S moved from position 801 in the measurement travel direction is set as the starting position for a measurement retry. Position 803 indicates the starting position for a measurement retry. Position 804 indicates the ending position for a measurement retry. Furthermore, the ending position of the measurement is independent of whether a measurement failure occurred; it can be the same or different. For example, in... Figure 7 In the example case, the range to be measured is from position "P2" to position "P3", but if the measurement fails, the starting position can be changed by measuring a range outside of that range.

[0142] Furthermore, in this embodiment, the starting position of the previous measurement is used as a reference to determine the starting position for the retry, but it is not limited to this. For example, the position where the measurement was determined to have failed can also be used as a reference to determine the starting position for the retry. Figure 8 In the case of the example, position 802 can also be used as a reference to determine the starting position during retry. Furthermore, this embodiment shows an example of changing the starting position during retry, but it is not limited to this. For example, it could also be a structure that switches the measurement conditions in the laser sensor 40. Examples of measurement conditions in the laser sensor 40 include, for example, the laser's illumination angle, illumination intensity, filter value, and number of samples.

[0143] Furthermore, in this embodiment, the number of retries in the event of a measurement failure is predetermined, and retries are performed within a range not exceeding this upper limit. However, this structure is not limited to this one; it could also be a structure that predefines an upper limit for the measurement time required, and retries are performed within a range not exceeding this upper limit.

[0144] Furthermore, this embodiment shows a structure with a laser sensor 40 as a detection unit in the welding system 1, but it is not limited to this. For example, in addition to the laser sensor 40, a vision sensor such as a camera or a touch sensor may also be included. In this case, if an error occurs, the vision sensor or touch sensor can be used instead of the laser sensor 40 for measurement. Moreover, if data is obtained normally through the measurement of the vision sensor or touch sensor, the structure can continue to perform automatic measurement or perform actions based on the welding procedure.

[0145] According to this embodiment, laser sensors can be used to perform measurement and position correction more efficiently, thereby improving welding operation efficiency.

[0146] [Variation Example]

[0147] In the above-described embodiment, if an error occurs during the measurement process, the system switches to measurement processing based on operator manual operation. At this time, if automatic measurement can continue as long as the measurement results from the laser sensor 40 can be determined more precisely, the system can automatically resume operation on the welding system 1 side. In other words, by suppressing the generation of errors, automatic measurement can continue. As a result, the frequency of operator manual operations can be reduced. Therefore, a modified structure for continuing automatic measurement through automatic recovery will be described.

[0148] For example, significant factors contributing to errors in the measurement by the laser sensor 40 include multifaceted laser reflection caused by the gloss of the welded object's surface, the presence of foreign matter such as debris or temporary attachments on the welded object's surface, and false detections caused by the complexity of the welded object's bevel. Furthermore, significant factors contributing to errors include incorrect teaching program settings and equipment malfunctions. Equipment malfunctions may include the laser sensor 40's protective glass becoming contaminated by spatter or fumes generated during welding, preventing laser illumination or light reception. If such phenomena can be identified at the welding system level and it can be determined that automatic measurement can continue, then measurement can automatically resume without operator intervention.

[0149] The following explains the treatment of various phenomena that are considered important factors that could lead to errors. Furthermore, examples of some of these important factors are provided for illustration. Therefore, by applying the same treatment to other important factors, it is possible to suppress the occurrence of errors.

[0150] (Multifaceted reflection)

[0151] If the surface of a workpiece to be welded has a glossy finish, irradiating it with a laser will cause laser reflection, sometimes making it impossible to accurately measure the shape of the workpiece. The degree of reflection varies depending on factors such as the shape of the bevel formed between the workpieces being welded, which serves as the root gap, and there are also cases where previously undetected areas are detected as surface areas.

[0152] Figure 9A Indicates to proceed Figure 9BAn example of the measurement results of the surface of workpiece 901 is shown. Here, workpiece 901 is shown as an example of a material with a relatively glossy finish. Dot group 910 represents the dot group detected by laser sensor 40. Line 911 represents the edge of workpiece 901 derived based on the dot group 910 obtained through measurement. Position 912 represents the center position of the bevel determined based on the results obtained through measurement. At this time, due to the gloss of workpiece 901, laser reflection occurs, and noise such as points 910a and 910b is detected. Therefore, a situation arises where the shape of workpiece 901 and the center position of the bevel cannot be accurately detected due to the influence of points 910a and 910b.

[0153] Figure 9B Briefly Figure 9A The measurement results. Figure 9B The arrows shown indicate the direction in which the laser is emitted by the laser sensor 40. For example... Figure 9B As shown, through reflection, points 910a and 910b are detected as noise at positions different from the surface of workpiece 901.

[0154] Considering the reflection from the workpiece surface as described above, for example, a noise-sensitive filter can be used to correct the measurement results. This filter could be, for example, a filter that removes points that are discontinuous with other point groups at a distance greater than a certain value. Figure 9C Indicates to Figure 9A The measurement results shown are an example of the edge of workpiece 901 derived by applying a noise removal filter. Point group 920 represents the point group detected by laser sensor 40 after applying the filter. Furthermore, line 921 represents the edge of workpiece 901 derived based on point group 920 after applying the filter. Furthermore, position 922 represents the center position of the bevel determined based on point group 920 after applying the filter.

[0155] Figure 9D Briefly Figure 9C The state after the filter is applied. Figure 9D The arrow indicates the direction of the laser beam emitted by the laser sensor 40. For example... Figure 9D As shown, noise caused by reflection, i.e., points 910a and 910b, is removed. As a result, the shape of workpiece 901 can be properly measured, and errors during measurement can be suppressed.

[0156] Additionally, this process can, for example, be performed in... Figure 5A If a measurement is deemed a failure in process S502, the measurement results can be filtered before reassessment. Alternatively, the measurement results can be filtered from the beginning before a determination can be made. For example, if it is assumed that the welding object has a glossy finish and exhibits multifaceted reflection, the measurement success can be determined after filtering the initial measurement results.

[0157] (foreign body)

[0158] During measurement, various foreign objects that can adhere to the surface of the workpiece can be identified, including debris such as cut ends of welding wire. Furthermore, temporary attachments on the workpiece surface can also be detected as foreign objects. While these debris needs to be removed to improve weld quality, temporary attachments disappear during the welding process and therefore do not require removal. In other words, even when foreign objects are detected, there are situations where operator intervention is required and situations where it is not. If this distinction can be made, errors can be suppressed, allowing automated measurement to continue.

[0159] Figure 10A This example shows a workpiece 1001 that is to be welded and a groove 1002 formed therebetween. The measured gap of the groove 1002 here is 3 mm. In addition, there is a foreign object 1003 near the groove 1002, which serves as the cut end of the welding wire.

[0160] Figure 10B Indicating targeting Figure 10A The workpiece 1001 shown is in a state where it is measured by laser sensor 40 irradiating laser 1004. At this time, it is assumed that laser 1004 measures the location of foreign object 1003.

[0161] Figure 10C This illustrates an example of the measurement results performed in the state shown in Figure 10. Point group 1020 represents the point group detected by laser sensor 40. Furthermore, bevel 1021 represents the bevel derived based on point group 1020 obtained through measurement. Additionally, position 1022 represents the center position of the upper part of bevel 1021. Here, an example is shown where the length of the upper part of bevel 1021, indicated by dashed line 1023, is measured as 20.39 mm. That is, because a foreign object 1003 is present on the surface of workpiece 1001, the gap width at which the end of the foreign object 1003 is taken as the end position of bevel 1021 is detected, instead of the original gap width of bevel 1021, which is 3 mm. As a result, as shown in bevel 1021, a range different from the original bevel is falsely detected. Correctly, the vicinity of point group 1020a corresponds to the edge portion of workpiece 1001.

[0162] For false detections caused by foreign objects as described above, the laser sensor 40 measures a fixed range to determine the abnormal value, i.e., the value of the range where foreign objects exist. Figure 10DThis indicates the state where the laser sensor 40 measures a range 1030 along the direction of the arrow to determine if a foreign object is present. Preferably, the measurement is performed in a manner that includes a range different from the area containing the foreign object 1003. In other words, if the measurement fails due to the presence of a foreign object, the success of the measurement can be determined during a retry based on the measurement results of the area surrounding the foreign object. Furthermore, the handling of the error can be adjusted based on the type of foreign object. For example, the measurement could be configured to determine whether the foreign object is temporarily attached or other types of debris based on the initial measurement results; no error would be generated if it is temporarily attached, but an error would be generated if it is other types of debris, thus requesting manual intervention.

[0163] Figure 11 Indicates to proceed Figure 10D The value obtained through measurement. In other words, it represents the measurement result performed while welding wire, which is a foreign object that needs to be manually removed, is present on the surface of workpiece 1001. Figure 11 In the diagram, the vertical axis represents the detected bevel gap width [mm], and the horizontal axis represents the data acquisition number. Here, the data acquisition number indicates the location measured by the laser sensor 40 at given intervals. The given intervals are predefined.

[0164] In this example, it is shown that... Figure 10D The example shown is a range 1030 with a length of 10 mm, a measurement speed of 60 cm / min, and a data acquisition period of 30 Hz. However, the measurement conditions are not limited to these; other values ​​can be used. Figure 11 In the data acquisition numbers “1” to “11” and “18” to “31”, the gap width is about 3mm. In contrast, the gap width increases sharply for data acquisition numbers “12” to “17”, and becomes about 29mm as the peak value at data acquisition number

[13] .

[0165] For example, in the case of temporary attachment, the likelihood of detecting a fixed area with the same width along the extension direction of the bevel is high. Therefore, in cases such as Figure 11 If extreme values ​​are detected within a certain range, it can be identified as the presence of debris rather than temporary attachment. In other words, the shape and type of foreign object can be determined based on the measurement results, and it can be identified whether the foreign object requires operator intervention or can be automatically measured without being detected.

[0166] Furthermore, if the overall range of data acquisition numbers is considered, the ranges of data acquisition numbers "1" to "11" and "18" to "31" can be treated as detection results for the bevel, and the gap width can be derived based on the value at that location. Figure 11In the example, the gap width was derived to be 3.3 mm, a value close to the actual gap width of the bevel.

[0167] Furthermore, errors in the teaching program settings and equipment malfunctions can also be determined based on obvious abnormalities identified by the detection results of the laser sensor 40.

[0168] As described above, filtering of the measurement results from the laser sensor 40 can also be performed, or the measurement range can be switched during retries when an anomaly is detected to determine the nature of the anomaly. This suppresses errors that might cause the operator to perform tasks, allowing automatic measurement to continue.

[0169] <Other Implementation Methods>

[0170] In this invention, programs or applications for implementing the functions of one or more of the above-described embodiments may also be supplied to a system or device via a network or storage medium, and one or more processors in the computer of the system or device may read and execute the program.

[0171] Alternatively, it can be implemented using a circuit that performs more than one function. Examples of circuits that perform more than one function include ASICs (Application Specific Integrated Circuits) and FPGAs (Field Programmable Gate Arrays).

[0172] As stated above, the following matters are disclosed in this specification.

[0173] (1) A control method for a welding robot, wherein the welding robot is equipped with a laser sensor.

[0174] The control method for the welding robot is characterized by having:

[0175] The process is determined by setting information in the control program of the welding robot, including setting the reference position measured by the laser sensor.

[0176] In the measurement process, the laser sensor is used to measure the welding object through the control program based on the set information.

[0177] The determination process determines whether the measurement in the measurement process was successful.

[0178] In the calculation process, if the measurement is determined to be successful in the determination process, based on the reference position and the measurement results in the measurement process, a correction amount for the control parameters of the welding robot is calculated; and

[0179] The retry process involves retrying the measurement process if the determination process determines that the measurement has failed.

[0180] Based on this structure, laser sensors can be used to perform measurement and position correction more efficiently, thereby improving the efficiency of welding operations.

[0181] (2) The control method of the welding robot according to (1), wherein, in the retest process, the measurement process of the measurement is retested within the range of the number of retests not exceeding the upper limit.

[0182] According to this structure, by setting an upper limit on the number of retries during automatic measurement, it is possible to suppress the generation of retries for useless measurements.

[0183] (3) The control method of the welding robot according to (1), wherein, in the retest process, the measurement of the measurement process is retested within the range that the required measurement time does not exceed the upper limit.

[0184] According to this structure, by setting a time-based upper limit for retries during automatic measurement, it is possible to suppress the generation of retries for useless measurements.

[0185] (4) The control method for the welding robot according to (2) or (3) further includes a notification process that, in the event that the measurement in the measurement process exceeds the upper limit value, the measurement fails and the user is prompted to perform an operation.

[0186] According to this structure, when a failure occurs in the measurement performed by the laser sensor, the operator can be appropriately notified to prompt the execution of the task.

[0187] (5) The control method for a welding robot according to any one of (1) to (4), wherein the method further comprises a determination step, wherein if the measurement of the measurement step is determined to be a failure in the determination step, the cause of the failure is determined based on the shape of the welding object measured by the laser sensor, and in the retry step, a decision is made on whether to retry the measurement of the measurement step based on the cause determined in the determination step.

[0188] According to this structure, when a measurement performed by a laser sensor fails, the system can determine whether to retry the automatic measurement or switch to manual operation by an operator, based on the nature of the failure. Therefore, by determining whether automatic measurement can continue based on the cause of the failure, and if it is determined that automatic measurement can continue, operator intervention can be suppressed.

[0189] (6) The control method for the welding robot according to (5), wherein, in the determining process, the type of foreign matter included in the measuring object is determined based on the measuring results of the measuring process.

[0190] In the retest process, the decision on whether to retest the measurement process depends on the type of foreign object.

[0191] According to this structure, when a foreign object is detected by the laser sensor, the system can determine whether to retry the automatic measurement or switch to manual operation based on the type of foreign object. Therefore, by determining whether automatic measurement can continue based on the type of foreign object, and if it is determined that automatic measurement can continue, operator intervention can be suppressed.

[0192] (7) The control method for the welding robot according to (5) or (6), wherein the cause of the failure is determined based on at least one of multifaceted reflection, foreign object, setting error, and equipment malfunction.

[0193] Based on this structure, various reasons related to measurement failure can be identified based on the measurement results of the laser sensor, and it is possible to determine in more detail whether automatic measurement can continue.

[0194] (8) The control method for a welding robot according to any one of (1) to (7), wherein, in the determination step, the determination of whether the measurement in the measurement step is successful is based on the result of filtering the measurement result for the measurement step.

[0195] According to this structure, for example, even if noise is included in the measurement results of the laser sensor due to the multifaceted reflection of the surface of the welded object, noise can be removed, resulting in more accurate measurements.

[0196] (9) The control method of the welding robot according to any one of (1) to (8), wherein, in the retest process, when retesting the measurement process, the measurement conditions of the laser sensor are set again.

[0197] According to this structure, by changing the measurement conditions during retesting, the failure of retesting can be suppressed, and measurement can be performed efficiently.

[0198] (10) The control method for the welding robot according to (9), wherein, in the retry process, as the measurement condition, for each retry, the start position or end position of the measurement of the laser sensor is changed at a predetermined position or a position calculated based on the error position.

[0199] According to this structure, remeasurement can be performed by changing the measurement location, and even if the measurement fails, remeasurement can be performed efficiently afterwards.

[0200] (11) The control method of the welding robot according to (9), wherein, in the retest process, as the measurement conditions, for each retest, at least one of the measurement angle, laser intensity, laser sensor filter value, and number of samples is changed.

[0201] According to this structure, remeasurement can be performed by changing the measurement location, and even if the measurement fails, remeasurement can be performed efficiently afterwards.

[0202] (12) The control method for the welding robot according to any one of (1) to (11), wherein,

[0203] In the calculation process, the correction amount is calculated based on the difference between the reference position and the measurement result in the measurement process.

[0204] The correction amount is transformed from the coordinate system of the laser sensor to the coordinate system of the welding robot, and based on the transformed correction amount, at least the control program is modified.

[0205] According to this structure, even when the laser coordinate system based on the laser sensor is different from the robot coordinate system based on the welding robot, the control program can be switched appropriately based on the measurement results of the laser sensor.

[0206] (13) The control method for the welding robot according to any one of (1) to (12), wherein,

[0207] The welding robot is also equipped with a vision sensor or a touch sensor.

[0208] If the measurement process is determined to have failed during the determination process, the visual sensor or the touch sensor shall be used for measurement.

[0209] According to this structure, even if the laser sensor fails to measure, welding can be performed efficiently without requiring operator intervention by using vision and touch sensors for automatic measurement.

[0210] (14) A control device for a welding robot, wherein the welding robot is equipped with a laser sensor.

[0211] The control device of the welding robot is characterized by having:

[0212] The decision unit determines the setting information in the control program of the welding robot, including the setting of the reference position measured by the laser sensor;

[0213] The measurement unit uses the laser sensor to measure the welding object through the control program based on the set information.

[0214] The determination unit determines whether the measurement performed by the laser sensor is successful.

[0215] The calculation unit, upon the determination unit determining that the measurement is successful, calculates a correction amount for the control parameters of the welding robot based on the reference position and the measurement results of the laser sensor; and

[0216] The retry unit retryes the measurement performed by the laser sensor if the determination unit determines that the measurement has failed.

[0217] Based on this structure, laser sensors can be used to perform measurement and position correction more efficiently, thereby improving the efficiency of welding operations. (15)

[0219] A welding system comprising: a laser sensor, a welding robot, and a control device, wherein the control device comprises:

[0220] The decision unit determines the setting information in the control program of the welding robot, including the setting of the reference position measured by the laser sensor;

[0221] The measurement unit uses the laser sensor to measure the welding object through the control program based on the set information.

[0222] The determination unit determines whether the measurement performed by the laser sensor is successful.

[0223] The calculation unit, upon the determination unit determining that the measurement is successful, calculates a correction amount for the control parameters of the welding robot based on the reference position and the measurement results of the laser sensor; and

[0224] The retry unit retryes the measurement performed by the laser sensor if the determination unit determines that the measurement has failed.

[0225] Based on this structure, laser sensors can be used to perform measurement and position correction more efficiently, thereby improving the efficiency of welding operations.

[0226] (16) A program for causing a computer to perform the following operations:

[0227] The process is determined by setting information in the control program of a welding robot equipped with a laser sensor, including setting a reference position based on the measurement of the laser sensor.

[0228] In the measurement process, the laser sensor is used to measure the welding object through the control program based on the set information.

[0229] The determination process determines whether the measurement in the measurement process was successful.

[0230] In the calculation process, if the measurement is determined to be successful in the determination process, based on the reference position and the measurement results in the measurement process, a correction amount for the control parameters of the welding robot is calculated; and

[0231] The retry process involves retrying the measurement process if the determination process determines that the measurement has failed.

[0232] Based on this structure, laser sensors can be used to perform measurement and position correction more efficiently, thereby improving the efficiency of welding operations.

Claims

1. A control method for a welding robot, wherein the welding robot is equipped with a laser sensor, The control method for the welding robot is characterized by having: The process is determined by setting information in the control program of the welding robot, including setting the reference position measured by the laser sensor. In the measurement process, the laser sensor is used to measure the welding object through the control program based on the set information. The determination process determines whether the measurement in the measurement process was successful or failed. In the calculation process, if the measurement is determined to be successful in the determination process, the correction amount for the control parameters of the welding robot is calculated based on the reference position and the measurement result in the measurement process. as well as The retry process involves retrying the measurement process if the determination process determines that the measurement has failed. The control method for the welding robot further includes: determining a process; and, if the determination process indicates a measurement failure in the measurement process, determining the cause of the failure based on the shape of the welding object measured by the laser sensor. In the retry process, a decision is made on whether to retry the measurement process based on the reasons determined in the determination process.

2. The control method for the welding robot according to claim 1, wherein, In the retry process, the measurement process is retried within the range where the number of retry attempts does not exceed the upper limit.

3. The control method for the welding robot according to claim 1, wherein, In the retest process, the measurement process is retested within the range where the required measurement time does not exceed the upper limit.

4. The control method for the welding robot according to claim 2, wherein, It also includes a notification process that, if the measurement in the measurement process exceeds the upper limit, it notifies the user of the measurement failure and prompts the user to take action.

5. The control method for the welding robot according to claim 3, wherein, It also includes a notification process that, if the measurement in the measurement process exceeds the upper limit, it notifies the user of the measurement failure and prompts the user to take action.

6. The control method for a welding robot according to any one of claims 1 to 5, wherein, In the determination process, the types of foreign matter included in the measurement object are determined based on the measurement results of the measurement process. In the retest process, the decision on whether to retest the measurement process depends on the type of foreign object.

7. The control method for a welding robot according to any one of claims 1 to 5, wherein, The cause of the failure is determined based on at least one of the following: multifaceted reflection, foreign object, setting error, or equipment malfunction.

8. The control method for a welding robot according to any one of claims 1 to 5, wherein, In the determination process, based on the result of filtering the measurement results of the measurement process, it is determined whether the measurement in the measurement process was successful or failed.

9. The control method for a welding robot according to any one of claims 1 to 5, wherein, In the retest process, when retesting the measurement process, the measurement conditions of the laser sensor are reset.

10. The control method for the welding robot according to claim 9, wherein, In the retry process, as a measurement condition, for each retry, the start or end position of the laser sensor measurement is changed at a predetermined position or a position calculated based on the error position.

11. The control method for the welding robot according to claim 9, wherein, In the retry process, as the measurement conditions, for each retry, at least one of the following is changed: measurement angle, laser intensity, laser sensor filter value, and number of samples.

12. The control method for a welding robot according to any one of claims 1 to 5, wherein, In the calculation process, the correction amount is calculated based on the difference between the reference position and the measurement result in the measurement process. The correction amount is transformed from the coordinate system of the laser sensor to the coordinate system of the welding robot. Based on the modified amount, at least the control program should be changed.

13. The control method for a welding robot according to any one of claims 1 to 5, wherein, The welding robot is also equipped with a vision sensor or a touch sensor. If the measurement process is determined to have failed during the determination process, the visual sensor or the touch sensor shall be used for measurement.

14. A control device for a welding robot, the welding robot being equipped with a laser sensor, The control device of the welding robot is characterized by having: The decision unit determines the setting information in the control program of the welding robot, including the setting of the reference position measured by the laser sensor; The measurement unit uses the laser sensor to measure the welding object through the control program based on the set information. The determination unit determines whether the measurement performed by the laser sensor is successful or unsuccessful. The calculation unit, when the determination unit determines that the measurement is successful, calculates the correction amount for the control parameters of the welding robot based on the reference position and the measurement result of the laser sensor. The retry unit retryes the measurement performed by the laser sensor if the determination unit determines that the measurement has failed. as well as The determining unit, when the determination unit determines that the measurement unit has failed, determines the cause of the failure based on the shape of the welding object measured by the laser sensor. The retry unit decides whether to retry based on the reason determined by the determining unit.

15. A welding system comprising: a laser sensor, a welding robot, and a control device, characterized in that, The control device has: The decision unit determines the setting information in the control program of the welding robot, including the setting of the reference position measured by the laser sensor; The measurement unit uses the laser sensor to measure the welding object through the control program based on the set information. The determination unit determines whether the measurement performed by the laser sensor is successful or unsuccessful. The calculation unit, when the determination unit determines that the measurement is successful, calculates the correction amount for the control parameters of the welding robot based on the reference position and the measurement result of the laser sensor. The retry unit retryes the measurement performed by the laser sensor if the determination unit determines that the measurement has failed. as well as The determining unit, when the determination unit determines that the measurement unit has failed, determines the cause of the failure based on the shape of the welding object measured by the laser sensor. The retry unit decides whether to retry based on the reason determined by the determining unit.

16. A program product for causing a computer to perform the following steps: The process is determined by setting information in the control program of a welding robot equipped with a laser sensor, including setting the reference position measured by the laser sensor. In the measurement process, the laser sensor is used to measure the welding object through the control program based on the set information. The determination process determines whether the measurement in the measurement process was successful or failed. In the calculation process, if the measurement is determined to be successful in the determination process, the correction amount for the control parameters of the welding robot is calculated based on the reference position and the measurement result in the measurement process. The retry process involves retrying the measurement process if the determination process determines that the measurement has failed. as well as In the determination process, if the measurement process is determined to have failed in the determination process, the cause of the failure is determined based on the shape of the welded object measured by the laser sensor. In the retry process, a decision is made on whether to retry the measurement process based on the reasons determined in the determination process.

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