Repair Welding Section Detection Method and Repair Welding Section Detection Device

Abstract

A repair welding segment detection method wherein: input data and master data for a non-defective workpieces are used to generate shape inconsistency data in which a location for which the shape of a weld bead is inconsistent is extracted; the shape inconsistency data is divided into N (where N is an integer of 2 or greater) equally divided windows in a direction perpendicular to the welding direction; a shift region formed by i (where i is an integer of one or greater) consecutive windows is set; the volume for each of (N-i+1) shift regions obtained by shifting one by one the i windows forming the shift region is calculated; and shift regions having a volume equal to or greater than a prescribed value are judged to be a weld bead defect segment.

Description

Technical Field

[0001] The present disclosure relates to a repair welding section detection method and a repair welding section detection device.

Background Art

[0002] Patent Document 1 discloses a shape inspection device that projects slit light onto a weld bead, images the shape lines sequentially formed on the weld bead by scanning the slit light, and acquires the three-dimensional shape of the weld bead as point cloud data based on the imaging data of each sequentially formed shape line. This shape inspection device sets an arbitrary cutting line different from the shape line formed by scanning the slit light on the weld bead displayed based on the point cloud data according to an input, and calculates the cross-sectional shape of the weld bead at the cutting line using the point cloud data corresponding to the cutting line. Further, the shape inspection device compares various feature amounts calculated according to the calculated cross-sectional shape with the allowable ranges of various feature amounts registered in advance, and determines the quality of the feature amounts.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a repair welding section detection method and a repair welding section detection device that more accurately detect the repair welding section of a workpiece produced by base welding.

Means for Solving the Problems

[0005] Input data regarding the weld bead of a workpiece produced by welding is input, an inspection determination regarding the shape of the weld bead is executed using the input data and master data of a non-defective workpiece, shape mismatch data in which portions of the weld bead with a shape mismatch are extracted is generated based on the result of the inspection determination, the shape mismatch data is divided into N (N: an integer of 2 or more) windows that are equally divided in a direction perpendicular to the welding direction of the weld bead, a shift region composed of i (i: an integer of 1 or more) consecutive windows out of the N windows is set, the volume of each of (N−i + 1) shift regions in which the i windows constituting the shift region are each shifted by one in the welding direction is calculated, and a shift region having a volume equal to or greater than a predetermined value among the volumes of the (N−i + 1) calculated shift regions is determined to be a defective section of the weld bead, thereby providing a repair welding section detection method.

[0006] Further, the present disclosure provides an input unit that inputs input data regarding the weld bead of a workpiece produced by welding, a determination unit that performs an inspection determination regarding the shape of the weld bead using the input data and master data of a non-defective workpiece, a data generation unit that generates shape mismatch data in which portions of the weld bead with a shape mismatch are extracted based on the inspection determination result of the determination unit, the shape mismatch data is divided into N (N: an integer of 2 or more) windows that are equally divided in a direction perpendicular to the welding direction of the weld bead, a shift region composed of i (i: an integer of 1 or more) consecutive windows out of each of the windows is set, a calculation unit that calculates the volume of each of (N−i + 1) shift regions in which the i windows constituting the shift region are each shifted by one in the welding direction, and a generation unit that determines that a shift region having a volume equal to or greater than a predetermined value among the volumes of the (N−i + 1) calculated shift regions is a defective section of the weld bead and generates information on the defective section.

Advantages of the Invention

[0007] According to the present disclosure, it is possible to more accurately detect a repair welding section of a workpiece produced by the present welding.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Embodiments for Carrying Out the Invention

[0009] (Background Leading to the Present Disclosure) As in Patent Document 1, when the calculated values of the characteristic quantities (for example, bead width, bead height, etc.) regarding the shape of the weld bead of the work produced by this welding are within the allowable range, it is determined to be a good product, and an apparatus configuration for automatically performing an appearance shape inspection of the weld bead has been conventionally known.

[0010] However, the shape of the weld bead may fluctuate due to changes in the working environment, deterioration of the consumables used for welding, dirt adhering to the work surface, etc. This fluctuation in the appearance shape of the weld bead does not necessarily affect the quality of the welding, and there are cases where repair welding is not required. However, when determining the necessity of repair welding based on the characteristic quantities of the shape mismatch portions of the entire weld bead calculated by comparing the shapes of the good product work and the work to be inspected, as in the conventional appearance shape inspection of the weld bead, repair welding may be determined to be necessary. For example, in the conventional appearance shape inspection of the weld bead, when the area of the shape mismatch portion is large and the shape fluctuation is small (specifically, when the excess height is slightly insufficient over the entire length of the weld bead, when the position of the weld bead is slightly shifted over the entire length, etc.), although the quality standard of the welding is satisfied, repair welding may be determined to be necessary and unnecessary repair welding may be performed.

[0011] Therefore, in the following embodiments, an example of a repair welding section detection method and a repair welding section detection apparatus for more accurately detecting the repair welding section of the work produced by this welding will be described.

[0012] Hereinafter, embodiments specifically disclosing a repair welding section detection method and a repair welding section detection apparatus according to the present disclosure will be described in detail with reference to the drawings as appropriate. However, a more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters and redundant descriptions of substantially the same configurations may be omitted. This is to avoid making the following description unnecessarily redundant and to facilitate the understanding of those skilled in the art. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and it is not intended to limit the subject matter described in the claims thereby.

[0013] The repair welding section detection apparatus according to the embodiment inputs input data regarding the weld bead of a workpiece produced by main welding, and performs a bead appearance inspection regarding the shape of the weld bead based on a comparison between the input data and master data of a non-defective workpiece using the input data and the master data. The repair welding program creation system determines a defective section (that is, a repair welding section that requires repair welding) for each defective location of the welding determined to require repair welding as a result of the bead appearance inspection.

[0014] Hereinafter, the object to be main welded (for example, metal) is defined as the "original workpiece", and the object produced (manufactured) by the main welding is defined as the "workpiece", respectively. Note that the "workpiece" may be defined to include a "repaired workpiece" in which a defective location of the welding detected in the appearance inspection has been repair welded. Also, the "workpiece" is not limited to a workpiece produced by a single main welding, and may be a composite workpiece produced by two or more main weldings.

[0015] The process of joining the original workpiece and another original workpiece by a welding robot to produce a workpiece is defined as "main welding", and the process of repairing a defective location of the workpiece by a welding robot, such as repair welding, is defined as "repair welding".

[0016] (Configuration of Welding System) FIG. 1 is a schematic diagram showing a system configuration example of a welding system 100. The welding system 100 includes a host device 1 connected to an external storage ST, an input interface UI1, and a monitor MN1, a robot control device 2, an inspection control device 3, a sensor 4, a welding robot MC1, and a monitor MN2. In FIG. 1, the sensor 4 is shown separately from the welding robot MC1, but may be provided integrally with the welding robot MC1 (see FIG. 2). Note that the monitor MN2 is not an essential component and may be omitted.

[0017] The host device 1 comprehensively controls the start and completion of the main welding executed by the welding robot MC1 via the robot control device 2. For example, the host device 1 reads welding-related information pre-input or set by a user (e.g., a welding operator or a system administrator; the same applies hereinafter) from the external storage ST, and uses the welding-related information to generate an execution command for the main welding including the content of the welding-related information and sends it to the corresponding robot control device 2. When the main welding by the welding robot MC1 is completed, the host device 1 receives a main welding completion report indicating that the main welding by the welding robot MC1 is completed from the robot control device 2, updates the status to indicate that the corresponding main welding is completed, and records it in the external storage ST.

[0018] Note that the execution command for the main welding described above is not limited to being generated by the host device 1, and may be generated by, for example, an operation panel of equipment (e.g., a PLC: Programmable Logic Controller) in a factory where the main welding is performed, or an operation panel of the robot control device 2 (e.g., a TP: Teach Pendant). Note that the teach pendant (TP) is a device for operating the welding robot MC1 connected to the robot control device 2.

[0019] In addition, the host device 1 comprehensively controls the start and completion of the bead appearance inspection using the robot control device 2, the inspection control device 3, and the sensor 4. For example, when the host device 1 receives a main welding completion report from the robot control device 2, it generates an execution command for the bead appearance inspection of the workpiece produced by the welding robot MC1 and sends it to each of the robot control device 2 and the inspection control device 3. When the bead appearance inspection is completed, the host device 1 receives an appearance inspection report indicating that the bead appearance inspection is completed from the inspection control device 3, updates the status to indicate that the corresponding bead appearance inspection is completed, and records it in the external storage ST.

[0020] Here, the welding-related information is information indicating the details of the main welding executed by the welding robot MC1, and is created in advance for each process of the main welding and registered in the external storage ST. The welding-related information includes, for example, the number of original workpieces used in the main welding, the ID, name, and workpiece information including the welding location of the original workpieces used in the main welding, the scheduled execution date when the main welding is to be executed, the production quantity of the workpieces to be welded, and various welding conditions during the main welding. Note that the welding-related information is not limited to the data of the above-mentioned items, and may include, for example, data related to the welding direction when the main welding is executed (that is, data of position information indicating the movement trajectory of the welding robot MC1). Also, the data related to the welding direction may be included in the teaching program of the welding robot MC1. Furthermore, the welding direction data of the welding robot MC1 may be generated in advance as welding direction data by inputting the information of the welding line together with the master data by user operation and stored in the memory 32 in the inspection control device 3.

[0021] Based on the execution command for the main welding sent from the upper-level device 1, the robot control device 2 causes the welding robot MC1 to start executing the main welding using the original workpiece specified by the execution command. Note that the above-mentioned welding-related information is not limited to being managed by the upper-level device 1 referring to the external storage ST. For example, it may be managed by the robot control device 2. In this case, since the robot control device 2 can grasp the state where the main welding is completed, the actual execution date may be managed instead of the scheduled execution date of the welding process among the welding-related information. Note that in this specification, regardless of the type of the main welding, for the sake of easy understanding of the explanation, a process of joining a plurality of original workpieces to produce one workpiece will be exemplified and explained.

[0022] The upper-level device 1 is connected so that data can be input and output between it and each of the monitor MN1, the input interface UI1, and the external storage ST, and is further connected so that data communication can be performed with the robot control device 2. The upper-level device 1 may be a terminal device P1 that integrally includes the monitor MN1 and the input interface UI1, and may further integrally include the external storage ST. In this case, the terminal device P1 is a PC (Personal Computer) used by the user prior to the execution of the main welding. Note that the terminal device P1 is not limited to the above-mentioned PC, and may be a computer device having a communication function such as a smartphone or a tablet terminal, for example.

[0023] The monitor MN1 may be configured using a display device such as an LCD (Liquid Crystal Display) or an organic EL (Electroluminescence), for example. The monitor MN1 may display a screen indicating, for example, a notification that the main welding has been completed or a notification that the bead appearance inspection has been completed, which is output from the upper-level device 1. Also, instead of the monitor MN1, or together with the monitor MN1, a speaker (not shown) may be connected to the upper-level device 1, and the upper-level device 1 may output the content indicating that the main welding has been completed or the content indicating that the bead appearance inspection has been completed as audio via the speaker.

[0024] The input interface UI1 is a user interface that detects a user's input operation and outputs it to the host device 1, and may be configured using, for example, a mouse, a keyboard, a touch panel, or the like. The input interface UI1 receives, for example, an input operation when the user creates welding-related information, or an input operation when sending an execution command for this welding to the robot control device 2.

[0025] The external storage ST is configured using, for example, a hard disk drive or a solid state drive. The external storage ST stores, for example, data on welding-related information created for each welding, the status (production status) of the workpiece produced by this welding, and the workpiece information of the workpiece (refer to the above).

[0026] The robot control device 2 is connected so as to enable data communication with the host device 1 and is also connected so as to enable data communication with the welding robot MC1. When the robot control device 2 receives an execution command for this welding sent from the host device 1, it controls the corresponding welding robot MC1 based on the execution command to execute this welding. When the robot control device 2 detects the completion of this welding, it generates a welding completion report indicating that this welding has been completed and notifies the host device 1. Thereby, the host device 1 can appropriately detect the completion of this welding by the robot control device 2. Note that the method for detecting the completion of this welding by the robot control device 2 may be, for example, a method of determining based on a signal indicating the completion of this welding from a sensor (not shown) provided in the wire feeding device 300, or a known method, and the content of the method for detecting the completion of this welding is not limited.

[0027] When the robot control device 2 receives an execution command for bead appearance inspection sent from the host device 1, it controls the welding robot MC1 (see Fig. 2) to which the sensor 4 is attached in accordance with an appearance inspection program created by the robot control device 2 or prepared in advance, and executes the bead appearance inspection of the corresponding workpiece based on the execution command. Note that an appearance inspection report indicating that the bead appearance inspection has been completed is sent from the inspection control device 3 to the host device 1, but it may also be sent from the robot control device 2 itself or from the robot control device 2 that has received an instruction from the inspection control device 3 to the host device 1. Thereby, the host device 1 can appropriately detect the completion of the bead appearance inspection.

[0028] The welding robot MC1 is connected so as to enable data communication with the robot control device 2. The welding robot MC1 executes the present welding commanded by the host device 1 under the control of the corresponding robot control device 2. When the sensor 4 is integrally attached to the welding robot MC1, the welding robot MC1 supports the execution of the bead appearance inspection commanded by the host device 1 by moving the sensor 4 in accordance with the appearance inspection program.

[0029] The inspection control device 3 as an example of the repair welding section detection device is connected so as to enable data communication with each of the host device 1, the robot control device 2, and the sensor 4. When the inspection control device 3 receives an execution command for bead appearance inspection sent from the host device 1, it executes the bead appearance inspection (for example, an inspection as to whether the welding bead formed on the workpiece satisfies a preset welding standard) of the welding portion of the workpiece produced by the welding robot MC1 together with the sensor 4. Note that the details of the bead appearance inspection will be described later with reference to Figs. 4 to 10. For example, the inspection control device 3 uses input data regarding the shape of the welding bead (for example, point cloud data capable of specifying the three-dimensional shape of the welding bead) acquired by the sensor 4 based on the workpiece welding portion information included in the execution command for bead appearance inspection, and performs the bead appearance inspection based on comparison with master data of a good workpiece preset for each workpiece.

[0030] The inspection control device 3 performs bead appearance inspection, generates an appearance inspection report including the inspection determination result of this bead appearance inspection and a notification indicating that the bead appearance inspection has been completed, sends it to the upper device 1, and outputs it to the monitor MN2. In addition, when the inspection control device 3 determines that a defect has been detected in the bead appearance inspection of the workpiece, it generates an appearance inspection report including the appearance inspection result including the information on the defective section for repair welding of the defect, and sends it to the upper device 1 and the robot control device 2.

[0031] Also, when the inspection control device 3 determines that a defect has been detected by the bead appearance inspection of the workpiece, it generates a repair welding program indicating that repairs such as repairing the defective location are to be performed using the appearance inspection result including the information on the defective section. The inspection control device 3 associates this repair welding program with the appearance inspection result and sends it to the upper device 1 or the robot control device 2.

[0032] The sensor 4 is connected so as to enable data communication with the inspection control device 3. When the sensor 4 is attached to the welding robot MC1 (see Fig. 2), the sensor 4 can operate to perform a three-dimensional scan of the mounting table on which the workpiece Wk is placed in response to the drive of the manipulator 200 based on the control of the robot control device 2. The sensor 4 acquires data (for example, point cloud data) that can identify the three-dimensional shape of the workpiece Wk placed on the mounting table (see Fig. 2) in response to the drive of the manipulator 200 based on the control of the robot control device 2, and sends it to the inspection control device 3.

[0033] The monitor MN2 may be configured using a display device such as an LCD or an organic EL. The monitor MN2 displays, for example, a screen indicating a notification that the bead appearance inspection has been completed, which is output from the inspection control device 3, or a screen indicating the notification and the result of the appearance inspection (information indicating the presence or absence of defects, information on the defective section, volume data of the welding bead lacking in the defective section, etc.). Instead of the monitor MN2, or together with the monitor MN2, a speaker (not shown) may be connected to the inspection control device 3, and the inspection control device 3 may output, via the speaker, a notification that the appearance inspection has been completed, or a voice indicating the content of the notification and the appearance inspection result (for example, the inspection determination result described above).

[0034] FIG. 2 is a diagram showing an example of the internal configuration of the inspection control device 3, the robot control device 2, and the host device 1 according to the embodiment. For easy understanding of the explanation, in FIG. 2, the monitors MN1, MN2, and the input interface UI1 are not shown. The work Wk shown in FIG. 2 is a work to be inspected for bead appearance. This work Wk may be a work produced by the main welding, or may be a so-called repaired work repaired one or more times by repair welding.

[0035] The welding robot MC1 executes various processes such as the main welding commanded from the host device 1 and the movement of the sensor 4 during the bead appearance inspection under the control of the robot control device 2. The welding robot MC1 performs, for example, arc welding in the process of the main welding. However, the welding robot MC1 may perform other welding (for example, laser welding, gas welding) other than arc welding. In this case, although not shown, instead of the welding torch 400, a laser head may be connected to the laser oscillator via an optical fiber. The welding robot MC1 has a configuration including at least a manipulator 200, a wire feeding device 300, a welding wire 301, and a welding torch 400.

[0036] The manipulator 200 is provided with an articulated arm and moves each arm based on a control signal from the robot control unit 24 of the robot control device 2. Thereby, the manipulator 200 can change the positional relationship between the work Wk and the welding torch 400 (for example, the angle of the welding torch 400 with respect to the work Wk) by driving the arm.

[0037] The wire feeder 300 controls the feeding speed of the welding wire 301 based on a control signal from the robot control device 2. The wire feeder 300 may be provided with a sensor (not shown) capable of detecting the remaining amount of the welding wire 301. The robot control device 2 can detect that the current welding process has been completed based on the output of this sensor.

[0038] The welding wire 301 is held by the welding torch 400. When power is supplied to the welding torch 400 from the power supply device 500, an arc is generated between the tip of the welding wire 301 and the work Wk, and arc welding is performed. For the sake of convenience in explanation, the configuration for supplying shielding gas to the welding torch 400 and the like are omitted from these drawings and descriptions.

[0039] The host device 1 generates an execution command for each of the various processes of the current welding or bead appearance inspection using welding-related information pre-input or set by the user, and sends it to the robot control device 2. As described above, when the sensor 4 is integrally attached to the welding robot MC1, the execution command for the bead appearance inspection is sent to both the robot control device 2 and the inspection control device 3. The host device 1 has a configuration including at least a communication unit 10, a processor 11, and a memory 12.

[0040] The communication unit 10 is connected so as to enable data communication with each of the robot control device 2 and the external storage ST. The communication unit 10 sends the execution commands for various processes of the main welding or bead appearance inspection generated by the processor 11 to the robot control device 2. The communication unit 10 receives the main welding completion report and the appearance inspection report sent from the robot control device 2 and outputs them to the processor 11. Note that the execution command for the main welding may include control signals for controlling each of the manipulator 200, wire feeding device 300, and power supply device 500 provided in the welding robot MC1, for example.

[0041] The processor 11 is configured using, for example, a CPU (Central Processing Unit) or an FPGA (Field Programmable Gate Array), and performs various processes and controls in cooperation with the memory 12. Specifically, the processor 11 functionally realizes the cell control unit 13 by referring to the program held in the memory 12 and executing the program.

[0042] The memory 12 has, for example, a RAM (Random Access Memory) as a work memory used when the processor 11 executes processing, and a ROM (Read Only Memory) that stores a program defining the processing of the processor 11. Data generated or acquired by the processor 11 is temporarily stored in the RAM. A program defining the processing of the processor 11 is written in the ROM. Further, the memory 12 stores the data of the welding-related information read from the external storage ST, the status of the workpiece, and the data of the workpiece information (refer to the above) of the workpiece sent from the robot control device 2, respectively.

[0043] The cell control unit 13 generates an execution command for performing main welding, bead appearance inspection of the workpiece, or repair welding based on the welding-related information stored in the external storage ST. Also, the cell control unit 13 creates an appearance inspection program for driving the welding robot MC1 during the bead appearance inspection of the workpiece Wk after main welding or one or more repair weldings based on the welding-related information stored in the external storage ST, and further creates an execution command for the appearance inspection program including this appearance inspection program. Note that this appearance inspection program may be created in advance and stored in the external storage ST. In this case, the cell control unit 13 simply reads and acquires the appearance inspection program from the external storage ST. The cell control unit 13 may generate different execution commands for each of the various processes of the main welding performed by the welding robot MC1. The execution command for the main welding generated by the cell control unit 13 or the execution command for the appearance inspection program including the appearance inspection program is sent to the corresponding robot control device 2 or each of the robot control device 2 and the inspection control device 3 via the communication unit 10.

[0044] Based on the execution command for main welding or bead appearance inspection sent from the host device 1, the robot control device 2 controls the processing of the corresponding welding robot MC1 (for example, the sensor 4, the manipulator 200, the wire feeding device 300, the power supply device 500). The robot control device 2 is configured to include at least a communication unit 20, a processor 21, and a memory 22.

[0045] The communication unit 20 is connected so as to enable data communication with the host device 1, the inspection control device 3, and the welding robot MC1. Although the illustration is simplified in FIG. 2, data transmission and reception are performed between the robot control unit 24 and the manipulator 200, between the robot control unit 24 and the wire feeding device 300, and between the power control unit 25 and the power supply device 500 via the communication unit 20, respectively. The communication unit 20 receives the execution command for main welding or bead appearance inspection sent from the host device 1. The communication unit 20 sends the workpiece information of the workpiece produced by the main welding to the host device 1.

[0046] Here, the workpiece information includes at least the ID of the workpiece, the ID, name, welding location, and welding conditions of the original workpiece used for this welding. Further, the workpiece information may include, as position information indicating the defective location of the workpiece, for example, position information indicating the defective section for each defective location, or position information indicating the start point and end point for each defective section. Also, the welding conditions are, for example, the material and thickness of the original workpiece, the material and wire diameter of the welding wire 301, the type of shielding gas, the flow rate of the shielding gas, the set average value of the welding current, the set average value of the welding voltage, the feeding speed and feeding amount of the welding wire 301, the number of welding passes, the welding time, etc. In addition to these, for example, information indicating the type of this welding (e.g., TIG welding, MAG welding, pulsed welding), the moving speed and moving time of the manipulator 200 may also be included.

[0047] The processor 21 is configured using, for example, a CPU or an FPGA, and cooperates with the memory 22 to perform various processes and controls. Specifically, the processor 21 refers to the program held in the memory 22 and executes the program to functionally realize the present welding program creation unit 23, the robot control unit 24, and the power control unit 25. Also, the processor 21 performs operations such as calculating parameters for controlling the welding robot MC1 (specifically, each of the manipulator 200, the wire feeding device 300, and the power supply device 500) controlled by the robot control unit 24 based on the present welding program generated by the present welding program creation unit 23.

[0048] Memory 22 includes, for example, a RAM used as a work memory when executing the processing of processor 21, and a ROM that stores a program defining the processing of processor 21. In the RAM, data generated or acquired by processor 21 is temporarily stored. In the ROM, a program defining the processing of processor 21 is written. Further, memory 22 stores data of the execution command for this welding or bead appearance inspection sent from the upper device 1, and data of the work information of the work produced by this welding respectively. Also, memory 22 stores the main welding program for the main welding executed by the welding robot MC1. The main welding program is a program that defines the specific procedure (process) of joining a plurality of base workpieces using the welding conditions in the main welding.

[0049] Based on the execution command for the main welding sent from the upper device 1 via the communication unit 20, the main welding program creation unit 23 generates the main welding program for the main welding executed by the welding robot MC1 using the work information (for example, ID, name, and welding location of the base workpiece) of each of the plurality of base workpieces included in the execution command. The main welding program may include various parameters such as welding current, welding voltage, offset amount, welding speed, and the posture of the welding torch 400 for controlling the power supply device 500, the manipulator 200, the wire feeding device 300, the welding torch 400, etc. during the execution of the main welding. Note that the main welding program may be stored in the processor 21 or in the RAM in the memory 22.

[0050] Based on the main welding program generated by the main welding program creation unit 23, the robot control unit 24 generates control signals for driving the welding robot MC1 (specifically, each of the manipulator 200, wire feeder 300, and power supply unit 500). The robot control unit 24 sends the generated control signals to the welding robot MC1. Also, based on the appearance inspection program sent from the host device 1, the robot control unit 24 drives the manipulator 200 of the welding robot MC1 during the bead appearance inspection so as to target the operating range of the welding robot MC1 defined in the main welding program. As a result, the sensor 4 (see FIG. 2) attached to the welding robot MC1 can move along with the operation of the welding robot MC1 and acquire input data regarding the shape of the weld bead of the workpiece Wk (for example, point cloud data that can specify the three-dimensional shape of the weld bead).

[0051] Based on the calculation result of the main welding program generated by the main welding program creation unit 23, the power supply control unit 25 drives the power supply unit 500.

[0052] Based on the execution command for bead appearance inspection sent from the host device 1, the inspection control device 3 controls the process of bead appearance inspection of the workpiece produced by the main welding by the welding robot MC1 or the workpiece repaired by one or more repair weldings. The bead appearance inspection is, for example, an inspection as to whether the weld bead formed on the workpiece meets a predetermined welding standard (for example, the quality standard of welding required by each user), and is constituted by the above-described inspection determination. The inspection control device 3 determines (inspects) whether the appearance shape of the weld bead formed on the workpiece Wk meets a predetermined welding standard based on the input data regarding the shape of the weld bead acquired by the sensor 4 (for example, point cloud data that can specify the three-dimensional shape of the weld bead). The inspection control device 3 has a configuration including at least a communication unit 30, a processor 31, a memory 32, and an inspection result storage unit 33.

[0053] The communication unit 30 is connected so as to enable data communication with the host device 1, the robot control device 2, and the sensor 4. Although the illustration is simplified in FIG. 2, data transmission and reception between the shape detection control unit 35 and the sensor 4 are performed via the communication unit 30, respectively. The communication unit 30 receives an execution command for bead appearance inspection sent from the host device 1. The communication unit 30 sends the inspection determination result of the bead appearance inspection using the sensor 4 (for example, the presence or absence of defects in the weld bead on the workpiece, position information regarding the defect section for each defect location, volume data of the weld bead lacking in the defect section) to the host device 1.

[0054] The processor 31 is configured using, for example, a CPU or an FPGA, and performs various processes and controls in cooperation with the memory 32. Specifically, the processor 31 refers to the program held in the memory 32 and executes the program to functionally realize the determination threshold storage unit 34, the shape detection control unit 35, the data processing unit 36, and the repair welding program creation unit 37.

[0055] The memory 32 has, for example, a RAM as a work memory used when the processor 31 executes processing, and a ROM that stores a program defining the processing of the processor 31. Data generated or acquired by the processor 31 is temporarily stored in the RAM. A program defining the processing of the processor 31 is written in the ROM. Further, the memory 32 stores the data of the execution command for the bead appearance inspection of the workpiece sent from the host device 1 and the data of the workpiece information of the workpiece, respectively.

[0056] The inspection result storage unit 33 is configured using, for example, a hard disk or a solid state drive. The inspection result storage unit 33 stores data indicating the inspection determination result of the bead appearance inspection at the welding location on the workpiece Wk (for example, the workpiece), as an example of data generated or acquired by the processor 31. The data indicating the inspection determination result of this bead appearance inspection is generated by, for example, the data processing unit 36.

[0057] The determination threshold storage unit 34 stores setting values (for example, various setting values for performing defect determination described later) and threshold values (for example, a threshold value related to the volume of the weld bead used for defect determination, information on the dead band width for detecting the end point of the defect section, etc.) used in the bead appearance inspection process according to the welding location. Further, the determination threshold storage unit 34 may store an allowable range (for example, a minimum allowable value, a maximum allowable value, etc.) that satisfies the minimum welding standard (quality) required from customers or the like as each threshold value during the bead appearance inspection.

[0058] Based on an execution command for bead appearance inspection of the welding location of the workpiece Wk sent from the host device 1, the shape detection control unit 35, which is an example of the input unit, acquires input data (for example, point cloud data capable of specifying the three-dimensional shape of the weld bead) related to the shape of the weld bead sent from the sensor 4 while the robot control device 2 operates the welding robot MC1 to which the sensor 4 is attached based on the appearance inspection program. When the sensor 4 reaches a position where it can image the weld bead (in other words, detect the three-dimensional shape of the welding location) in response to the driving of the manipulator 200 by the robot control device 2 described above, the shape detection control unit 35, for example, causes the sensor 4 to irradiate a laser beam to acquire input data (for example, point cloud data capable of specifying the three-dimensional shape of the weld bead) related to the shape of the weld bead. When the shape detection control unit 35 receives the input data (refer to the above) acquired by the sensor 4, it passes this input data to the data processing unit 36.

[0059] As an example of the determination unit, data generation unit, calculation unit, and generation unit, when the data processing unit 36 acquires the input data (refer to the above) regarding the shape of the weld bead from the shape detection control unit 35, it converts the acquired input data into a data format suitable for bead appearance inspection. Note that the data processing unit 36 counts the number of times of bead appearance inspection for each defect location determined to be a defect. If the welding inspection result does not improve even when the number of times of bead appearance inspection exceeds the number stored in advance in the memory 32, it may be determined that it is difficult or impossible to correct the defect location by repair welding. In this case, the data processing unit 36 generates an alert screen including the work information for which it is determined that it is difficult or impossible to correct the defect location by repair welding, the information on the position of the defect section for repair welding of the defect location, and the type of defect (for example, perforation, pit, undercut, protrusion), and sends the generated alert screen to the upper device 1 via the communication unit 30. The alert screen sent to the upper device 1 is displayed on the monitor MN1. Note that this alert screen may also be displayed on the monitor MN2.

[0060] The data processing unit 36 performs a bead appearance inspection based on the comparison between the input data regarding the shape of the weld bead acquired by the sensor 4 and the master data of the non-defective work preset in advance for each work, using the threshold value for bead appearance inspection stored in the determination threshold storage unit 34. Specifically, the data processing unit 36 performs a comparison (so-called image processing) between the data (for example, image data generated based on point cloud data) data-converted by the data processing unit 36 and the master data of the non-defective work, and extracts the shape mismatch locations where it is determined that the shape of the weld bead indicated by the input data does not match. The data processing unit 36 generates shape mismatch data based on the extracted shape mismatch locations of the input data, and determines whether there is a defect location that requires repair welding for each shape mismatch location included in the generated shape mismatch data, and the position of the defect section of the defect location.

[0061] The data processing unit 36 creates an appearance inspection report including a defect determination result as an inspection determination result (that is, information indicating the presence or absence of a defect that requires repair welding) and information on the defect section for each defect location, stores it in the inspection result storage unit 33, and sends it to the host device 1 or the robot control device 2 via the communication unit 30. Further, when the data processing unit 36 determines that there is no defect location on the work Wk that requires repair welding, the data processing unit 36 creates an appearance inspection report including an inspection determination result indicating that the bead appearance inspection is passed, stores it in the inspection result storage unit 33, and sends it to the host device 1 via the communication unit 30.

[0062] The repair welding program creation unit 37 creates a repair welding program for the work Wk to be executed by the welding robot MC1 using the appearance inspection report of the work Wk by the data processing unit 36. The repair welding program may include various parameters such as welding current, welding voltage, offset amount, welding speed, and the posture of the welding torch 400 for controlling the power supply device 500, the manipulator 200, the wire feeding device 300, the welding torch 400, etc. during the execution of the repair welding. The generated repair welding program may be stored in the processor 31, may be stored in the RAM in the memory 32, or may be sent to the host device 1 or the robot control device 2 via the communication unit 30 in association with the appearance inspection report.

[0063] The sensor 4 is, for example, a three-dimensional shape sensor, which is attached to the tip of the welding robot MC1 and can acquire a plurality of point cloud data that can identify the shape of the welding location on the work Wk (for example, the work), and generates point cloud data that can identify the three-dimensional shape of the welding location based on this point cloud data and sends it to the inspection control device 3. Incidentally, when the sensor 4 is not attached to the tip of the welding robot MC1 and is arranged separately from the welding robot MC1, based on the position information of the welding location sent from the inspection control device 3, a laser light source (not shown) configured to be able to scan the welding location on the work Wk (for example, the work or repair work), and a camera (not shown) arranged to be able to image an imaging area including the periphery of the welding location and image the reflection locus of the reflected laser light among the laser light irradiated on the welding location (that is, the shape line of the welding location). In this case, the sensor 4 sends the shape data of the welding location (in other words, the image data of the welding bead) based on the laser light imaged by the camera to the inspection control device 3. Incidentally, the above-described camera is configured to have at least a lens (not shown) and an image sensor (not shown). The image sensor is a solid-state imaging device such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semi-conductor), and converts the optical image formed on the imaging surface into an electrical signal.

[0064] (Operation of the welding system) Next, a series of operation procedures of this welding and bead appearance inspection by the welding system 100 according to the embodiment will be described with reference to FIG. 3. FIG. 3 is a sequence diagram showing an example of a series of processing procedures including this welding and bead appearance inspection by the welding system 100 according to the embodiment. In the description of FIG. 3, the operation procedures performed between the host device 1, the robot control device 2, and the inspection control device 3 regarding the process of generating an appearance inspection report including the result of defect determination and the information on the position of the defect section based on the fact that this welding using a plurality of original workpieces and the bead appearance inspection of the workpiece are determined to be unqualified will be exemplified and described.

[0065] In FIG. 3, the host device 1 acquires the work information (e.g., ID, name, and welding location of the original work) of the original work to be welded respectively (St1), and generates an execution command for the present welding including the work information of the original work. The host device 1 sends the execution command for the present welding including the work information of the original work to the robot control device 2 (St2). Note that the robot control device 2 may execute the processes of step St1 and step St2 without going through the host device 1. In this case, it is preferable that the same data as the data stored in the external storage ST is stored in the memory 22 of the robot control device 2, or the robot control device 2 is connected so as to be able to acquire data from the external storage ST.

[0066] When the robot control device 2 receives the execution command for the present welding sent from the host device 1, it creates a welding program for the present welding to be executed by the welding robot MC1 using the work information of each of the plurality of original works included in the execution command, and causes the welding robot MC1 to execute the present welding according to the welding program (St3). When the robot control device 2 determines the completion of the present welding by various known methods, it generates a welding completion notification indicating that the present welding is completed and sends it to the host device 1 (St4). When receiving the welding completion notification, the host device 1 generates an execution command for an appearance inspection program including an appearance inspection program for the work and sends it to the robot control device 2 (St5), and generates an execution command for a bead appearance inspection of the work and sends it to the inspection control device 3 (St6). The robot control device 2 executes the appearance inspection program received from the host device 1 with the start of the bead appearance inspection and moves the sensor 4 attached to the welding robot MC1 along the welding line (St7). While the sensor 4 is moved by the robot control device 2 so as to be able to scan the welding location of the work, it acquires point cloud data capable of specifying the three-dimensional shape of the work (St7).

[0067] The inspection control device 3 uses, as input data, point cloud data that can identify the three-dimensional shape of the weld bead acquired by the sensor 4, and executes the bead appearance inspection described above (St8). The inspection control device 3 acquires this welding program from the robot control device 2, and performs an inspection determination (that is, defect determination and determination of the defective section) of the bead appearance of the weld bead of the workpiece (St8). Note that the details of the processing in step St8 will be described later with reference to FIGS. 4 to 10.

[0068] As the inspection determination result in step St8, when the inspection control device 3 determines that there is a defect in the workpiece by defect determination (St8), based on the information on the welding direction in which the workpiece was produced, it determines (detects) the defective section for each defective location for repair welding, and generates an appearance inspection report including the defect determination result and the information on the position of the defective section for each defective location (St9). On the other hand, when the inspection control device 3 determines that there is no defect in the workpiece by defect determination as the inspection determination result in step St8 (St8), it generates an appearance inspection report including the inspection determination result indicating that the bead appearance inspection is passed (St9).

[0069] Thereby, the inspection control device 3 can acquire the information on the welding direction when this welding is executed. The inspection control device 3 generates an appearance inspection report including the inspection determination result executed in step St8 and sends it to the robot control device 2 (St10). Also, the inspection control device 3 sends the similarly generated appearance inspection report to the upper device 1 as well (St11).

[0070] Next, the details of the process of performing defect determination and determination (detection) of the defective section as the inspection determination executed in step St8 of FIG. 3 will be described with reference to FIGS. 4 to 10. FIG. 4 is a flowchart showing an example of the defect determination and determination (detection) processing procedure according to the embodiment.

[0071] The point cloud data that can identify the three-dimensional shape of the weld bead B1 acquired by the sensor 4 is used for bead appearance inspection. The data processing unit 36 converts the point cloud data from the sensor 4 into a data format suitable for bead appearance inspection (for example, image data showing the three-dimensional shape of the weld bead) and passes it to the data processing unit 36. The data processing unit 36 reads and acquires the master data MD1 (for example, image data showing the ideal three-dimensional shape of the weld bead of the good workpiece) of the good workpiece stored in the memory 32 (St8-1).

[0072] The data processing unit 36 compares the image data RT1 (inspection target data) from the data processing unit 36 with the master data MD1, and extracts shape mismatch locations (for example, each of the shape mismatch locations ED1, ED2, and ED3 shown in FIG. 5) where the shapes do not match. The data processing unit 36 generates shape mismatch data EDD1 (see FIG. 6) of the weld bead B1 based on each of the extracted shape mismatch locations ED1 to ED3 (St8-2). Note that the shape mismatch data EDD1 shown in FIG. 6 shows an example of shape mismatch data generated including each of the plurality of shape mismatch locations ED1 to ED3 for the sake of simplicity of explanation. However, the shape mismatch data EDD1 is not limited to the above example, and for example, one shape mismatch data may be generated for each shape mismatch location.

[0073] Here, with reference to FIG. 5, the weld bead B1 and the master data MD1 will be described. FIG. 5 is a diagram showing an example of shape mismatch locations ED1, ED2, and ED3 between the weld bead B1 and the master data MD1. In FIG. 5, the master data MD1 is shown by a solid line, the weld bead B1 is shown by a broken line, and a shape mismatch region ED where the shapes of the weld bead B1 and the master data MD1 do not match is shown by hatching. As shown in FIG. 5, the data processing unit 36 compares the shape of the weld bead B1 with the master data MD1 and extracts the shape mismatch locations ED1, ED2, and ED3 respectively. Note that the weld bead B1, the master data MD1, and the shape mismatch locations ED1 to ED3 shown in FIG. 5 are examples and are not limited thereto.

[0074] Next, with reference to FIGS. 6 and 7, an example of shape mismatch data and a window used in the defect determination process in the present embodiment will be described. FIG. 6 is a diagram for explaining an example of windows ΔV[1], ΔV[2], …, ΔV[m], …, ΔV[N] when the shape mismatch data EDD1 is divided into N equal parts. FIG. 7 is a diagram showing an example of a cross-sectional view in a direction perpendicular to the welding direction of the shape mismatch data EDD2. Note that the shape mismatch data EDD1 shown in FIG. 6 is shape mismatch data generated based on the shape mismatch portions ED1 to ED3 shown in FIG. 5, and is a view seen from the Z direction. Further, FIG. 7 shows a cross-section SS1 when the shape mismatch data EDD2 is cut by a cutting plane CS1 in a direction perpendicular to the welding direction M2, and a cross-section SS2 when cut by a cutting plane CS2.

[0075] The data processing unit 36 acquires information on the welding direction M1 in which the weld bead B1 is produced, and sets N windows ΔV[1], ΔV[2], …, ΔV[m], …, ΔV[N] obtained by dividing the shape mismatch data EDD1 into N equal parts (N: an integer of 2 or more) at equal intervals ΔD in a direction perpendicular to the welding direction M1 (St8-3). Here, the window ΔV[k] indicates the volume calculated by multiplying the cross-sectional area S[k] of the k-th (k: an integer of 1 or more) of the N equal parts of the shape mismatch data EDD1 by the interval ΔD.

[0076] Note that the cross-sectional area S[k] shown in FIG. 6 shows an example of being calculated by approximating the cross-section of the shape mismatch data EDD1 with a rectangle, but is not limited thereto. For example, as shown in FIG. 7, the cross-sectional area S[k] may be calculated by calculating the areas of the respective cross-sections SS1 and SS2, or may be calculated based on an approximate shape obtained by approximating each of the cross-sections SS1 and SS2 with an arbitrary polygon.

[0077] Furthermore, the number N of windows (i.e., the number of windows) obtained by cutting the interval ΔD or the shape mismatch data EDD1 here may have either one set as a fixed value. Note that the length of the interval ΔD may be set by an operator to any length preset based on the quality criteria required by the user, or a length based on the total length of the shape mismatch data EDD1 in the welding direction M1 (for example, when the total length of the shape mismatch data EDD1 is 50 mm or more, ΔD = 5 mm, or when it is 100 mm or more, ΔD = 10 mm, etc.) may be set. Similarly, the number N of windows may be set by an operator to any number based on the quality criteria required by the user, or a number preset based on the total length of the shape mismatch data EDD1 in the welding direction M1 (for example, when the total length of the shape mismatch data EDD1 is 50 mm or more, N = 5, or when it is 100 mm or more, N = 10, etc.) may be set.

[0078] The data processing unit 36 sets (St8-4) (N - i + 1) shift regions PS1, PS2, …, PS(N - i + 1) (see FIG. 8) each composed of i (i: an integer of 1 or more) consecutive windows out of each of the N windows ΔV[1], …, ΔV[N]. Here, the shift regions PS1, PS2, …, PS(N - i + 1) will be described with reference to FIG. 8. FIG. 8 is a diagram for explaining an example of the shift regions PS1, PS2, …, PS(N - i + 1) and the shift operation of the shift regions.

[0079] As shown in FIG. 8, each shift region PS1, PS2, …, PS(N-i+1) is composed of i windows. The i windows that make up each shift region PS1, PS2, …, PS(N-i+1) are different in that the window number k is shifted one by one in the welding direction M1. Specifically, the shift region PS1 is composed of i windows from window ΔV[1] to window ΔV[i]. The shift region PS2 is composed of i windows from window ΔV[2] to window ΔV[i+1] with the i windows that make up the shift region PS1 shifted one in the welding direction M1. Similarly, the shift region PS(N-i+1) is composed of i windows from window ΔV[N-i] to window ΔV[N]. Note that the number i of windows that make up one shift region may be set to any value of 1 or more by the operator based on the quality standard for each user.

[0080] The data processing unit 36 calculates the volume of the shift region and determines whether the calculated volume of the shift region is equal to or greater than the threshold value stored in the determination threshold value storage unit 34 (St8-4). When the data processing unit 36 determines that the volume of the shift region is equal to or greater than the threshold value, it determines that this shift region is a defective portion that requires repair welding (St8-4). The data processing unit 36 sequentially executes the calculation of the volume of each of the (N-i+1) shift regions PS1, PS2, …, PS(N-i+1) and the defect determination from the first shift region PS1 to the (N-i+1)-th shift region PS(N-i+1) among the (N-i+1) shift regions, and sequentially executes the determination of the start point and the end point of the defective section based on the result of the defect determination (St8-4). Thereby, the data processing unit 36 can more accurately determine whether there is a defect that does not meet the user's quality standard and requires repair welding for each shift region based on the volume of the shape mismatch portion per reference length (that is, the interval ΔD), and determines the start point and the end point of the defective section to be repaired based on the shift region determined to be the defective portion (St8-4). Hereinafter, the method for determining the start point and the end point will be described.

[0081] When the data processing unit 36 determines that the volume of the k-th shift region calculated is a defect, it determines whether the previous (i.e., the (k - 1)-th) shift region is non-defective. When the data processing unit 36 determines that the previous shift region is non-defective and the volume of the k-th shift region is defective, it determines that any position in the k-th shift region is the start point of the defect interval. When the data processing unit 36 determines that the first (i.e., k = 1) shift region is defective, it determines that any position in the first shift region is the start point of the defect interval.

[0082] Also, after determining the start point, when the data processing unit 36 determines that the volume of the k-th shift region calculated is defective and the (k + 1)-th shift region is non-defective, it determines that any position in the k-th shift region is the end point of the defect interval. When the data processing unit 36 determines that the (N - 1)-th (i.e., k = N - 1) shift region is defective and the N-th (i.e., k + 1 = N) shift region is defective, it determines that any position in the N-th shift region is the end point of the defect interval.

[0083] When the data processing unit 36 determines that a single non-continuous shift region is a defective location, it may determine that the first window among the i windows constituting this shift region is the start point of the defect interval and the i-th window among the i windows is the end point of the defect interval.

[0084] Furthermore, when the data processing unit 36 uses the center of a single non-continuous shift region, it may determine that the start point and the end point of the defect interval are the same point. In this way, when the start point and the end point of the defect interval are the same point, the repair welding program creation unit 37 generates a repair welding program for repair welding this defect interval (the same point) by, for example, spot welding, and causes the welding robot MC1 to perform repair welding by spot welding.

[0085] Next, other determination processing methods for the start point and the end point will be described. When the data processing unit 36 determines that two or more consecutive shift regions are defective portions, among the two or more consecutive shift regions, the first window among the i windows constituting the shift region first determined to be a defective portion, or the center of the shift region may be determined as the start point of the defective section. Similarly, when the data processing unit 36 determines that two or more consecutive shift regions are defective portions, among the two or more consecutive shift regions, the i-th window among the i windows constituting the shift region last determined to be a defective portion, or the center of the shift region may be determined as the end point of the defective section. Note that the center of the shift region may be the center position of the shift region or the i / 2-th window among the i windows.

[0086] Furthermore, when the first shift region PS1 among two or more consecutive shift regions is determined to be a defective portion by the data processing unit 36, the first window among the i windows may be determined as the start point of the defective section. Also, when the last shift region PS(N - i + 1) among two or more consecutive shift regions is determined to be a defective portion by the data processing unit 36, the i-th window among the i windows may be determined as the end point of the defective section. Thereby, in the defect determination based on the volume of the shape mismatch portion per reference length (that is, the interval ΔD), the data processing unit 36 can determine (detect) a defective section that can more suppress the repair welding omission of the defect in the first shift region PS1 and the (N - i + 1)-th shift region PS(N - i + 1) where the position of the defect to be repair-welded is difficult to specify.

[0087] Based on the determined start point and end point, the data processing unit 36 specifies (detects) the defective section of each defective portion (St8-5). Here, a defective portion refers to a single defective portion including a plurality of consecutive defective portions.

[0088] Here, with reference to FIG. 9, the processes executed in step St8-4 and step St8-5 will be described in detail using a specific example. FIG. 9 is a diagram for explaining an example of defect determination and defect section determination according to the embodiment. In FIG. 9, the shape mismatch data is divided into seven equal parts (that is, N = 7), the number of windows i = 3, and the volume threshold T = 4.0 mm 3 The determination example when set to is shown.

[0089] Also, the determination of the start point and end point of the defect section shown in FIG. 9 is as follows: In the first determination example, the first of the three windows constituting the first shift region determined as a defect is determined as the start point of the defect section, and the third of the three windows constituting the last shift region is determined as the end point of the defect section. In the second determination example, the first (that is, the integer number of i = 3 / 2) as the central position among the three windows constituting the first shift region determined as a defect is the start point of the defect section, and the first (that is, the integer number of i = 3 / 2) as the central position among the three windows constituting the last shift region is the end point of the defect section. However, it goes without saying that it is not limited to this. For example, the data processing unit 36 may determine the second window among the three windows as the central position in the second determination example.

[0090] The volume of the k-th shift region V[k] is the total value of the volume of window ΔV[k], the volume of window ΔV[k + 1], and the volume of window ΔV[k + 2]. The data processing unit 36 calculates the volume of the first shift region V[1], and the calculated volume of the first shift region V[1] is 3.5 mm 3 is not greater than the threshold T = 4.0 mm 3 Therefore, it is determined that the first shift region V[1] is a non-defective portion.

[0091] The data processing unit 36 calculates the second shift region V[2], and the calculated volume of the second shift region V[2] is 4.5 mm 3 is greater than the threshold T = 4.0 mm 3Therefore, since the above conditions are met, it is determined that the second shift region V[2] is a defective location. Since the previous shift region (i.e., the first shift region V[1]) is a non-defective location, the data processing unit 36 executes the determination of the start point of the defective section in the second shift region V[2]. Specifically, in the first determination example, the data processing unit 36 determines the first window ΔV[2] among the three windows constituting the second shift region V[2] as the start point RCA1 of the defective section RCA at this defective location. In the second determination example, the data processing unit 36 determines the window ΔV[2] at the central position among the three windows constituting the second shift region V[2] as the start point RCB1 of the defective section RCB at this defective location.

[0092] The data processing unit 36 calculates the volume of the third shift region V[3], and the calculated volume of the third shift region V[3] is 4.8 mm 3 is greater than or equal to the threshold value T = 4.0 mm 3 Therefore, since the above conditions are met, it is determined that the third shift region V[3] is a defective location. Since the previous shift region (i.e., the second shift region V[2]) is a defective location, the determination of the end point of the defective section is omitted. Similarly, the data processing unit 36 calculates the volume of the fourth shift region V[4], and the calculated volume of the fourth shift region V[4] is 4.8 mm 3 and is greater than or equal to the threshold value T = 4.0 mm 3 Therefore, since the above conditions are met, it is determined that the fourth shift region V[4] is a defective location. Since the previous shift region (i.e., the third shift region V[3]) is a defective location, the determination of the end point of the defective section is omitted.

[0093] The data processing unit 36 calculates the volume of the fifth shift region V[5], and the calculated volume of the fifth shift region V[5] is 3.3 mm 3 is greater than or equal to the threshold value T = 4.0 mm 3Since it is not the above, it is determined that the fifth shift region V[5] is a non-defective portion. Since the data processing unit 36 determines that the previous shift region (that is, the fourth shift region V[4]) is a defective portion and the fifth shift region V[5] is a non-defective portion, the data processing unit 36 executes the determination of the end point of the defective section in the fourth shift region V[4]. Specifically, in the first determination example, the data processing unit 36 determines that the third window ΔV[6] among the three windows constituting the fourth shift region V[4] is the end point RCA2 of the defective section RCA at this defective portion, and in the second determination example, the data processing unit 36 determines that the middle window ΔV[4] among the three windows constituting the fourth shift region V[4] is the end point RCB2 of the defective section RCB at this defective portion.

[0094] As described above, the data processing unit 36 shown in FIG. 9 determines that the region from the position of the start point RCA1 (that is, the window ΔV[2]) to the position of the end point RCA2 (that is, the window ΔV[6]) is the defective section RCA in the first determination example, and determines that the region from the position of the start point RCB1 (that is, the window ΔV[2]) to the position of the end point RCB2 (that is, the window ΔV[4]) is the defective section RCB in the second determination example.

[0095] The data processing unit 36 repeatedly executes the repeat process RP1 from step St8-3 to step St8-5 for each shape mismatch portion, and generates the volume data of the welding bead lacking in each defective section (see FIG. 10) (St8-6). Note that the process of step St8-6 is not essential and may be omitted.

[0096] Here, referring to FIG. 10, the volume data VD1 will be described. FIG. 10 is a diagram showing an example of the volume data VD1 of the shape mismatch portions ED2, ED3 and the defect intervals RC2, RC3 of the weld bead B1. Note that the weld bead B1 shown in FIG. 10 has each of the three shape mismatch portions ED1, ED2, ED3, and an example is shown in which two of these three shape mismatch portions ED2, ED3 are determined to be defects by the data processing unit 36. Further, in the example shown in FIG. 10, the data processing unit 36 determines the defect interval RC2 of the shape mismatch portion ED2 from the start point RC21 to the end point RC22, and determines the defect interval RC3 of the shape mismatch portion ED3 from the start point RC31 to the end point RC32.

[0097] The data processing unit 36 generates volume data VD1 by extracting the volume of the weld bead lacking in the defect intervals RC2 and RC3 in the welding direction M1 from the shape mismatch data (not shown) generated by extracting the shape mismatch region ED from the entire length of the weld bead B1. Here, the data processing unit 36 may generate repair welding condition data VD2 in which volume values are plotted at positions corresponding to the positions of the plurality of windows included in the respective defect intervals RC2, RC3 in the generated volume data VD1. Note that the repair welding condition data VD2 is not limited to simply data approximating the volume values. For example, based on the volume data VD1, as an example of the repair welding conditions, data indicating the feeding amount of the welding wire 301 for repair welding each of the defect intervals RC2, RC3, or data indicating the welding current value or the welding voltage value of the power supply device 500 for controlling the welding torch 400 for repair welding each of the defect intervals RC2, RC3 may be generated.

[0098] The data processing unit 36 generates an appearance inspection report (St8-7) that includes at least notification information for notifying whether there is a defect as an inspection determination result (that is, whether repair welding is necessary) and information on the defect interval for each location with a shape mismatch. Note that when the data processing unit 36 generates volume data or repair welding data in step St8-6, it generates an appearance inspection report that further includes the generated volume data or repair welding condition data.

[0099] As described above, the inspection control device 3 according to the embodiment can more accurately determine whether a shape mismatch (defect) that requires repair welding exists at a location with a shape mismatch based on the comparison between the appearance shape of the weld bead and the master data of the non-defective workpiece, and can more appropriately determine (detect) the repair welding interval (defect interval) that requires repair welding. Therefore, unnecessary repair welding can be efficiently reduced. In addition, since the inspection control device 3 can set a shift region for defect determination based on the quality standard of welding required by the user, the usability for the user in determining the presence or absence of a defect that requires repair welding and in determining (detecting) the repair welding interval (defect interval) can be improved.

[0100] For example, when the operator sets the number i of windows constituting the shift region to a small value, the operator can more accurately determine the presence or absence of a defect that requires repair welding, and can make the repair welding interval (defect interval) obtained by the determination shorter. On the other hand, when the operator sets the number i of windows constituting the shift region to a value of i = 2 or more, the operator can more suppress the false determination of a defect due to the influence of noise included in the appearance shape of the weld bead acquired by the sensor 4, and can reduce the processing load generated by the defect determination and the defect interval determination process. In addition, such an effect can be similarly obtained not only by the value of the number i of windows constituting the shift region but also by adjusting the value of the interval ΔD indicating the width of the window in the welding direction.

[0101] (Modification of the embodiment) The inspection control device 3 according to the above-described embodiment has been shown as an example of performing defect determination and determination (detection) of a defect section for each defect based on a threshold value related to an arbitrary volume stored in the determination threshold value storage unit 34. An example of the inspection control device 3 according to a modification of the embodiment will be described in which defect determination and determination (detection) of a defect section for each defect are performed based on a first threshold value related to an arbitrary volume stored in the determination threshold value storage unit 34 and a second threshold value based on this first threshold value.

[0102] Note that the defect determination and determination (detection) processing procedure according to the modification of the embodiment is different from the defect determination and determination (detection) processing procedure example according to the embodiment shown in FIG. 4 in the processing of step St8-4. Therefore, in the description of the defect determination and determination (detection) processing procedure according to the modification of the embodiment shown below, the processing of step St8-4 will be described, and the description of other processing procedures will be omitted.

[0103] The inspection control device 3 according to the modification of the embodiment stores in the determination threshold value storage unit 34 a first threshold value T1 used for defect determination (the first threshold value T1 referred to here is the same as the threshold value used for defect determination in the embodiment) and a dead zone width Z (0 < Z < 1) used for calculating a second threshold value T2 for determining the end point of the defect section. The second threshold value T2 is calculated by multiplying the first threshold value T1 by (1 - Z). Note that the dead zone width Z may be a value indicated as a percentage.

[0104] Note that the dead zone width Z may be set to a predetermined relative value with respect to the first threshold value, or may be set to a specified value (constant value). For example, when the first threshold value ≧ 10.0 mm 3 Z = 2.0 mm 3 , when the first threshold value < 10.0 mm 3 Z = 1.0 mm 3 and so on, or Z = 2.0 mm 3 may be set as a specified value regardless of the value of the first threshold value.

[0105] As described above, the inspection control device 3 according to the modification of the embodiment changes the threshold value (first threshold value T1) used for determining the start point of the defective section and the threshold value (second threshold value T2) used for determining the end point of the defective section. Here, the second threshold value T2 is a volume value smaller than the first threshold value T1. Thereby, when the inspection control device 3 according to the modification of the embodiment determines the start point in the determination of the defective section (repair welding section) to be repair welded, the criterion for non-defect (end of defect) can be made stricter in the defect determination of the continuous shift region. That is, when the volume of the shift region (in other words, the volume difference between the appearance shape of the weld bead and the master data) does not satisfy the condition of being equal to or less than the changed second threshold value T2, the inspection control device 3 determines that the defective section has not ended. Therefore, it is possible to determine (detect) a defective section that can further suppress the occurrence of repair omission in the repair welding executed based on the information of the generated defective section.

[0106] With reference to FIG. 11, the defect determination and the determination (detection) process of the defective section according to the modification of the embodiment will be described. FIG. 11 is a diagram for explaining the determination of the start point and the end point of the defective section according to the modification of the embodiment. The volume graph V3 shown in FIG. 11 is a graph in which the volume of each of a plurality of shift regions calculated by the data processing unit 36 is plotted.

[0107] The first threshold value T1 is a threshold value used for determining the start point of the defective section according to the modification of the embodiment. The second threshold value T2 is a threshold value used for determining the end point of the defective section according to the modification of the embodiment. The difference between the first threshold value T1 and the second threshold value T2 is a value obtained by multiplying the first threshold value T1 by the dead band width Z.

[0108] The data processing unit 36 calculates the volume of the shift region and determines whether the calculated volume of the shift region is equal to or greater than the first threshold value T1 regarding the volume stored in the memory 32 (that is, the determination of the start point of the defective section RCC). When the data processing unit 36 determines that the calculated volume of the shift region is equal to or greater than the first threshold value T1 (for example, point RCC1 shown in FIG. 11), it determines that this shift region is a defective portion that requires repair welding and determines the start point of the defective portion.

[0109] After determining that the starting point of the defective portion is the position indicated by point RCC1, the data processing unit 36 changes the threshold value used for defect determination of the shift region continuous in the welding direction (that is, determination of the end point of the defective section RCC) from the first threshold value T1 to the second threshold value T2.

[0110] When the data processing unit 36 determines that the volume of the calculated shift region is equal to or less than the second threshold value T2 (for example, point RCC2 shown in FIG. 11), it determines that this shift region is a non-defective portion, and determines the end point of the defective section from the shift region determined to be a non-defective portion.

[0111] After determining that the end point of the defective section is the position indicated by point RCC2, the data processing unit 36 changes the threshold value used for defect determination of the shift region continuous in the welding direction (that is, determination of the starting point of the defective section RCD) from the second threshold value T2 to the first threshold value T1, and sequentially executes the defect determination of each shift region while shifting the window one by one along the welding direction.

[0112] When the data processing unit 36 determines that the volume of the calculated shift region is equal to or greater than the first threshold value T1 (for example, point RCD1 shown in FIG. 11), it determines that this shift region is a defective portion that requires repair welding, and determines the starting point of the defective portion. After determining that the starting point of the defective portion is the position indicated by point RCD1, the data processing unit 36 changes the threshold value used for defect determination of the shift region continuous in the welding direction (that is, determination of the end point of the defective section RCD) from the first threshold value T1 to the second threshold value T2. In FIG. 11, illustration of the subsequent volume graph V3 and description of various determination processes are omitted.

[0113] As described above, the data processing unit 36 in the modification of the embodiment changes the volume threshold value used for defect determination from the first threshold value T1 to the second threshold value T2 after determining the start point of the defect section, and changes the volume threshold value used for defect determination from the second threshold value T2 to the first threshold value T1 after determining the end point of the defect section. Then, from the first shift region PS1 to the (N - i + 1)-th shift region PS(N - i + 1) among the (N - i + 1) shift regions PS1, PS2, …, PS(N - i + 1), the above-described defect determination and the determination of the start point and end point of the defect section based on the result of the defect determination are sequentially executed (St8-4).

[0114] Note that the method for determining the start point in the first shift region determined to be a defect and the method for determining the end point in the last shift region determined to be a defect are the same as the determination methods shown in the embodiment, so the description thereof is omitted.

[0115] Here, with reference to FIGS. 12 to 14, a defect determination and a determination processing example of a defect section executed in step St8-4 and step St8-5, and a determination processing example of a repair welding start point and a repair welding end point will be described. FIG. 12 is a diagram for explaining a determination example of the start point and end point of a defect section according to a modification of the embodiment. FIG. 13 is a diagram for explaining a determination example of the start point and end point of a defect section according to a modification of the embodiment. FIG. 14 is a diagram for explaining a coordinate calculation example of the start point and end point in a defect section according to a modification of the embodiment. Note that in the determination example of the defect determination and the start point and end point of the defect section shown in FIG. 12, the shape mismatch data ED4 shown in FIG. 13 is divided into 10 equal parts (that is, N = 10), the number of windows i = 3, the dead band width Z = 0.2, and the first threshold value T1 = 4.0 mm 3 is set. The second threshold value T2 shown in FIG. 12 is calculated as T2 = 3.2 mm 3 based on the first threshold value T1 and the dead band width Z.

[0116] In addition, regarding the determination of the start point and end point of the defective section shown in FIG. 12, an example is shown in which the first one (i.e., the integer part of i = 3 / 2) among the three windows constituting the first shift region determined as a defect is determined as the start point, and the first one (i.e., the integer part of i = 3 / 2) among the three windows constituting the last shift region determined as a defect is determined as the end point. However, it goes without saying that it is not limited to this.

[0117] The volume of the k-th shift region V[k] is the total value of the volume of window ΔV[k], the volume of window ΔV[k + 1], and the volume of window ΔV[k + 2]. The data processing unit 36 calculates the first shift region V[1], and the volume of the calculated first shift region V[1] is 3.0 mm 3 is less than the first threshold value T1 = 4.0 mm 3 Therefore, it is determined that the first shift region V[1] is non-defective.

[0118] The data processing unit 36 calculates the second shift region V[2], and the volume of the calculated second shift region V[2] is 3.5 mm 3 is less than the first threshold value T1 = 4.0 mm 3 Therefore, it is determined that the second shift region V[2] is non-defective.

[0119] The data processing unit 36 calculates the third shift region V[3], and the volume of the calculated third shift region V[3] is 4.3 mm 3 is greater than or equal to the first threshold value T1 = 4.0 mm 3 Therefore, it is determined that the third shift region V[3] is defective. Since the previous shift region (i.e., the second shift region V[2]) is non-defective, the determination (detection) of the start point of the defective section is executed in the third shift region V[3]. Specifically, the data processing unit 36 determines the window ΔV[4] at the central position among the three windows constituting the third shift region V[3] as the start point RCE1 of the defective section RCE in this defect. After determining the start point RCE1 of the defective section RCE, the data processing unit 36 changes the threshold value used for defect determination from the first threshold value T1 to the second threshold value T2.

[0120] The data processing unit 36 calculates the volume of the fourth shift region V[4], and the volume of the calculated fourth shift region V[4] is 3.5 mm 3 is not less than the second threshold value T2 = 3.2 mm 3 Therefore, it is determined that the fourth shift region V[4] is a defect.

[0121] The data processing unit 36 calculates the fifth shift region V[5], and the volume of the calculated fifth shift region V[5] is 2.5 mm 3 is less than or equal to the second threshold value T2 = 3.2 mm 3 Therefore, it is determined that the fifth shift region V[5] is non-defective. Since the previous shift region (i.e., the fourth shift region V[4]) is defective, the determination (detection) of the end point of the defective section is executed from the fifth shift region V[5]. Specifically, the data processing unit 36 determines the window ΔV[6] at the central position among the three windows constituting the fifth shift region V[5] as the end point RCE2 of the defective section RCE in this defect. After determining the end point RCE2 of the defective section RCE, the data processing unit 36 changes the threshold value used for defect determination from the second threshold value T2 to the first threshold value T1.

[0122] The data processing unit 36 calculates the sixth shift region V[6], and the volume of the calculated sixth shift region V[6] is 1.7 mm 3 is not less than the first threshold value T1 = 4.0 mm 3 Therefore, it is determined that the sixth shift region V[6] is non-defective.

[0123] The data processing unit 36 calculates the seventh shift region V[7], and the volume of the calculated seventh shift region V[7] is 8.5 mm 3 is not less than the first threshold value T1 = 4.0 mm 3Therefore, it is determined that the seventh shift region V[7] is defective. Since the previous shift region (i.e., the sixth shift region V[6]) is non-defective, the start point of the defective section is determined (detected) from the seventh shift region V[7]. Specifically, the data processing unit 36 determines the window ΔV[8] at the central position among the three windows constituting the seventh shift region V[7] as the start point RCF1 of the defective section RCF in this defect. After determining the start point RCF1 of the defective section RCF, the data processing unit 36 changes the threshold value used for defect determination from the first threshold value T1 to the second threshold value T2.

[0124] The data processing unit 36 calculates the volume of the eighth shift region V[8], and the volume of the calculated eighth shift region V[8] is 9.0 mm 3 is not less than the second threshold value T2 = 3.2 mm 3 Therefore, it is determined that the eighth shift region V[8] is defective. Also, after determining the defect of the eighth shift region V[8], since there is no next shift region, the end point of the defective section is determined (detected) from this eighth shift region V[8]. Specifically, the data processing unit 36 determines the window ΔV[9] at the central position among the three windows constituting the eighth shift region V[8] as the end point RCF2 of the defective section RCF in this defect.

[0125] As a result of the defect determination and the determination (detection) of the defective section of the shape mismatch data ED4 shown in FIG. 13, the data processing unit 36 generates an appearance inspection report including the information of the first defective section RCE (i.e., the position information of the start point RCE1 and the end point RCE2) and the information of the second defective section RCF (i.e., the position information of the start point RCF1 and the end point RCF2), and ends the defect determination and the determination (detection) process of the shape mismatch data ED4 shown in FIG. 13.

[0126] After the defect determination and the determination (detection) process of the defective section, the data processing unit 36 executes a calculation process for the coordinates of the start point and the end point of the defective section as the repair welding section for actually executing repair welding by the welding robot MC1. The data processing unit 36 extracts the point cloud data of each window ΔV[k] including the positions of the respective start points and the respective end points obtained as the determination results from the shape mismatch data ED4. In the example shown in FIG. 14, the data processing unit 36 includes the point cloud data ED41 in the window ΔV[4] including the position of the start point RCE1 in the defective section RCE, the point cloud data ED42 in the window ΔV[6] including the position of the end point RCE2 in the defective section RCE, the point cloud data ED43 in the window ΔV[9] including the position of the start point RCF1 in the defective section RCF, and the point cloud data ED44 in the window ΔV

[10] including the position of the end point RCF2 in the defective section RCF.

[0127] The data processing unit 36 calculates the centroid coordinates of each of the extracted point cloud data ED41 to ED44, and outputs the centroid coordinates calculated as the coordinates for executing repair welding by the welding robot MC1. Specifically, in the example shown in FIG. 14, the data processing unit 36 calculates the coordinates (X1, Y1, Z1) of the start point RCE1 in the defective section RCE, the coordinates (X2, Y2, Z2) of the end point RCE2 in the defective section RCE, the coordinates (X3, Y3, Z3) of the start point RCF1 in the defective section RCF, and the coordinates (X4, Y4, Z4) of the end point RCF2 in the defective section RCF based on each of the extracted point cloud data.

[0128] Note that the center-of-gravity coordinates of each point cloud data ED41 to ED44 calculated here are not limited to the center-of-gravity coordinates calculated based on each point cloud data ED41 to ED44, and may be the center-of-gravity coordinates calculated based on a part of each point cloud data ED41 to ED44. For example, when the data processing unit 36 calculates the coordinates of the starting point in the defect section, from the position of the cross-sectional area S[k] corresponding to the k-th window ΔV[k] including the position of the starting point, in the same direction as the welding direction M3, by an interval of ΔD / 2 or ΔD / 3 (that is, a part), the center-of-gravity coordinates of the point cloud data may be calculated. Also, the cutting plane used for calculating the coordinates of the end point of the defect section may calculate the center-of-gravity coordinates of the point cloud data in an interval of ΔD / 2 or ΔD / 3 (that is, a part) in the direction opposite to the welding direction M3 from the position of the cross-sectional area S[k + 1] corresponding to the (k + 1)-th window ΔV[k + 1] continuous with the k-th window ΔV[k] including the position of the end point.

[0129] As a result of the defect determination of the shape mismatch data ED4 and the determination (detection) of the defect section by the data processing unit 36, an appearance inspection report including information on the first defect section RCE (that is, the position (coordinate) information of the starting point RCE1 and the end point RCE2) and information on the second defect section RCF (that is, the position (coordinate) information of the starting point RCF1 and the end point RCF2) is generated, and the calculation process of the coordinates of the starting point and the end point of the defect section of the shape mismatch data ED4 shown in FIG. 13 is completed.

[0130] Note that the method for calculating the coordinates of the starting point and the end point of the defect section is not limited to the above example. Hereinafter, with reference to FIGS. 15 and 16, other calculation methods for the coordinates of the starting point and the end point of the defect section executed by the data processing unit 36 will be described. FIG. 15 is a diagram for explaining an example of calculating the coordinates of the starting point and the end point in the defect section according to a modification of the embodiment.

[0131] In the example shown in FIG. 15, the data processing unit 36 extracts, from each of the extracted point cloud data ED41 to ED44, the point with the shortest distance from the welding direction M3 (that is, the movement locus of the welding robot MC1), and the point with the longest distance from the welding direction M3, and calculates the coordinates of the midpoint of these two extracted points as the coordinates of the start point or the end point in the defect interval.

[0132] Specifically, the data processing unit 36 extracts the point SP11 with the shortest distance from the welding direction M3 and the point SP12 with the longest distance from the welding direction M3 from the extracted point cloud data ED41, and calculates the coordinates of the midpoint of these two extracted points as the coordinates (X5, Y5, Z5) of the start point RCE3 in the defect interval RCE. Then, the data processing unit 36 extracts the point SP21 with the shortest distance from the welding direction M3 and the point SP22 with the longest distance from the welding direction M3 from the extracted point cloud data ED42, and calculates the coordinates of the midpoint of these two extracted points as the coordinates (X6, Y6, Z6) of the end point RCE4 in the defect interval RCE. Similarly, the data processing unit 36 extracts the point SP31 with the shortest distance from the welding direction M3 and the point SP32 with the longest distance from the welding direction M3 from the extracted point cloud data ED43, and calculates the coordinates of the midpoint of these two extracted points as the coordinates (X7, Y7, Z7) of the start point RCF3 in the defect interval RCF. Also, the data processing unit 36 extracts the point SP41 with the shortest distance from the welding direction M3 and the point SP42 with the longest distance from the welding direction M3 from the extracted shape mismatch data ED4, and calculates the coordinates of the midpoint of these two extracted points as the coordinates (X8, Y8, Z8) of the end point RCF4 in the defect interval RCF.

[0133] Based on the results of the defect determination and the defect interval determination (detection) of the shape mismatch data ED4, the data processing unit 36 generates an appearance inspection report including the information of the first defect interval RCE (that is, the position (coordinate) information of the start point RCE3 and the end point RCE4) and the information of the second defect interval RCF (that is, the position (coordinate) information of the start point RCF3 and the end point RCF4).

[0134] FIG. 16 is a diagram for explaining an example of calculating coordinates of a start point and an end point in a defective section according to a modification of the embodiment. In FIG. 16, regarding the method of calculating coordinates, a detailed explanation will be given with reference to an enlarged view EX obtained by enlarging the point group data ED41 of the window ΔV[4] including the start point RCE5 of the defective section RCE. The illustration of the enlarged view in the other point group data ED42, ED43, ED44 is omitted.

[0135] In the example shown in FIG. 16, the data processing unit 36 extracts the point group data of each window ΔV[k] including the respective positions of each start point and each end point obtained as determination results from the shape mismatch data ED4. When the point group data of the extracted window ΔV[k] includes the position of the start point in the defective section, the data processing unit 36 calculates the coordinates of the point closest to the cutting plane corresponding to this window ΔV[k] (that is, the cutting plane (plane) forming the cross-sectional area S[k] used for calculating the volume of the window ΔV[k]) among the points included in the point group data as the coordinates of the start point in the defective section. Further, when the point group data of the window ΔV[k] includes the position of the end point in the defective section, the data processing unit 36 calculates the coordinates of the point closest to the cutting plane corresponding to the next window ΔV[k + 1] of the extracted window ΔV[k] (that is, the cutting plane (plane) forming the cross-sectional area S[k + 1] used for calculating the volume of the window ΔV[k + 1]) as the coordinates of the end point in the defective section. In other words, when the point group data of the window ΔV[k] includes the position of the end point in the defective section in calculating the coordinates of the end point in the defective section, the data processing unit 36 calculates the coordinates of the point farthest from the cutting plane corresponding to this window ΔV[k] (that is, the cutting plane (plane) forming the cross-sectional area S[k] used for calculating the volume of the window ΔV[k]) among the points included in the point group data as the coordinates of the end point in the defective section.

[0136] The calculation formula for the coordinates of a point as the start point or end point of a defective section in the example shown in Fig. 16 is shown in (Equation 1). (Equation 1) is the equation representing the cutting plane (plane). (Equation 2) is the formula for calculating the distance D0 between the point as the start point or end point and the cutting plane. Here, the normal vector of the cutting plane (plane) is set as (A, B, C). The coordinates of the point as the start point or end point of the defective section are set as (X0, Y0, Z0).

[0137]

Number

[0138]

Number

[0139] Specifically, the data processing unit 36 calculates the distances D11, D12, D13, D14, D15 between each of the plurality of points EDD included in the extracted point cloud data ED41 and the cutting plane CS41 corresponding to the window ΔV[4] including the start point RCE5 of the defective section RCF, and calculates the coordinates of the point with the closest distance to the cutting plane CS41 among the calculated distances D11 to D15 of the plurality of points (in the example shown in Fig. 16, the distance D11 is the smallest value) as the coordinates (X9, Y9, Z9) of the start point RCE5 of the defective section RCE. Note that the signs of the points EDD in the point cloud data ED41 shown in Fig. 16 are illustrated for only some of the points, and are omitted for other points and the start point RCE5. Similarly, the signs indicating the distances between each of the plurality of points EDD and the cutting plane CS41 are illustrated for only some of the points EDD, and are omitted for other points.

[0140] The data processing unit 36 calculates the distance between each of a plurality of points (not shown) included in the extracted point cloud data ED42 and the cutting plane CS42 corresponding to the next window ΔV[7] adjacent to the window ΔV[6] including the end point RCE6 of the defect section RCE, and calculates the coordinates of the point with the shortest distance from the cutting plane CS42 among the calculated distances of the plurality of points as the coordinates (X10, Y10, Z10) of the end point RCE6 of the defect section RCE. Note that the data processing unit 36 may calculate the distance between each of a plurality of points (not shown) included in the extracted point cloud data ED42 and the cutting plane corresponding to the window ΔV[6] including the end point RCE6 of the defect section RCE, and calculate the coordinates of the point with the longest distance from the cutting plane among the calculated distances of the plurality of points as the coordinates (X10, Y10, Z10) of the end point RCE6 of the defect section RCE.

[0141] Similarly, the data processing unit 36 calculates the distance between each of a plurality of points (not shown) included in the extracted point cloud data ED43 and the cutting plane CS43 corresponding to the window ΔV[8] including the start point RCF5 of the defect section RCF, and calculates the coordinates of the point with the longest distance from the cutting plane CS43 among the calculated distances of the plurality of points as the coordinates (X11, Y11, Z11) of the start point RCF5 of the defect section RCF. Further, the data processing unit 36 calculates the distance between each of a plurality of points (not shown) included in the extracted point cloud data ED44 and the cutting plane CS44 corresponding to the next window ΔV

[10] adjacent to the window ΔV[9] including the end point RCF6 of the defect section RCF, and calculates the coordinates of the point with the shortest distance from the cutting plane CS44 among the calculated distances of the plurality of points as the coordinates (X12, Y12, Z12) of the end point RCF6 of the defect section RCF.

[0142] As a result of the defect determination and defect section determination (detection) of the shape mismatch data ED4, the data processing unit 36 generates an appearance inspection report including information on the first defect section RCE (that is, position (coordinate) information of the start point RCE5 and the end point RCE6) and information on the second defect section RCF (that is, position (coordinate) information of the start point RCF5 and the end point RCF6).

[0143] As described above, as an example of the inspection control device 3 of the repair welding section detection device according to the embodiment and the modification of the embodiment, the inspection control device 3 inputs input data (for example, point cloud data) regarding the weld bead of the workpiece Wk produced by welding, and uses the input data and the master data of the non-defective workpiece to execute an inspection determination regarding the shape of the weld bead. Based on the result of the inspection determination, shape mismatch data is generated by extracting the shape mismatch locations of the weld bead, and the shape mismatch data is divided into N (N: an integer of 2 or more) windows that are equally divided in a direction perpendicular to the welding direction of the weld bead. A shift region composed of i (i: an integer of 1 or more) consecutive windows out of the N windows is set, and the volumes of the (N - i + 1) shift regions obtained by shifting the i windows constituting the shift region one by one in the welding direction are calculated respectively. A shift region having a volume equal to or greater than a predetermined value among the calculated volumes of the (N - i + 1) shift regions is determined to be a defective section of the weld bead.

[0144] Thereby, the inspection control device 3 according to the embodiment and the modification of the embodiment can more accurately determine whether there is a defect that does not meet the user's quality standard and needs to be repair-welded based on the volume of the shape mismatch locations per reference length (that is, interval ΔD), and can detect the start point and the end point of the defective section that needs to be repair-welded based on the shift region determined to be the defective location.

[0145] Also, as described above, the inspection control device 3 according to the embodiment and the modification of the embodiment sequentially executes the calculation of the volumes of the (N - i + 1) shift regions and the determination process of the defective section (N - i + 1) times along the welding direction. Thereby, the inspection control device 3 according to the embodiment and the modification of the embodiment can execute the defect determination of the shift region while shifting at intervals of ΔD, so that the position of the defective location (that is, the defective section) that does not meet the user's quality standard and needs to be repair-welded can be detected more accurately.

[0146] Further, based on the above, the inspection control device 3 according to the embodiment and the modification of the embodiment determines the first window among the i windows included in one or more shift regions determined to be defective regions as the start point of the defective region, and determines the i-th window as the end point of the defective region. In this determination method, for example, when the inspection control device 3 determines a single non-continuous shift region as defective, it determines (detects) the entire area of this shift region as the defective region, and when it determines two or more continuous shift regions as defective, it detects the entire area of these two or more shift regions as the defective region. Thereby, the inspection control device 3 according to the embodiment and the modification of the embodiment can more accurately determine the position of the defective portion (i.e., the defective region) to be repair welded among the shape mismatch portions, and can suppress the omission of detection of the defective region.

[0147] Further, based on the above, when the inspection control device 3 according to the embodiment and the modification of the embodiment determines that two or more continuous shift regions are defective regions, it determines the first window among the i windows constituting the shift region first determined as the defective region among the two or more continuous shift regions as the start point of the defective region, and determines the i-th window among the i windows included in the shift region finally determined as the defective region as the end point of the defective region. Thereby, the inspection control device 3 according to the embodiment and the modification of the embodiment can more accurately detect the defective region to be repair welded among the shape mismatch portions.

[0148] Further, based on the above, when the inspection control device 3 according to the embodiment and the modification of the embodiment determines that the first shift region among the (N - i + 1) shift regions is a defective region, it determines the first window among the i windows constituting the first shift region as the start point of the defective region. Thereby, the inspection control device 3 according to the embodiment and the modification of the embodiment can detect the defective region for repairing the defect in the first shift region PS1, where the position of the defect to be repair welded is difficult to identify, without omission.

[0149] Further, as described above, when the inspection control device 3 according to the embodiment and the modification of the embodiment determines that the (N - i + 1)-th shift region among the (N - i + 1) shift regions is a defective section, it determines that the i-th window among the i windows constituting the (N - i + 1)-th shift region is the end point of the defective section. Thereby, the inspection control device 3 according to the embodiment and the modification of the embodiment can detect a defective section for reliably repair-welding a defect that is difficult to specify the position of in the (N - i + 1)-th shift region PS(N - i + 1) where repair welding should be performed without omission.

[0150] Further, as described above, when the inspection control device 3 according to the embodiment and the modification of the embodiment determines that two or more consecutive shift regions are defective sections, it determines the central position of the shift region first determined to be a defective section as the start point of the defective section, and determines the central position of the shift region finally determined to be a defective section as the end point. Thereby, the inspection control device 3 according to the embodiment and the modification of the embodiment can more accurately detect a defective section that should be repair-welded among the shape mismatch portions.

[0151] Further, as described above, when the inspection control device 3 according to the modification of the embodiment determines that any k-th shift region among the (N - i + 1) shift regions is a defective section, any window included in this shift region is set as the start point of the defective section, and it is determined whether the volume of the (k + 1)-th shift region continuous with the shift region is less than or equal to a second threshold value (an example of a second predetermined value) that is smaller than a first threshold value (an example of a predetermined value). When the volume of the (k + 1)-th shift region is less than or equal to the second predetermined value, any window constituting the (k + 1)-th shift region is determined as the end point of the defective section. Thereby, when the inspection control device 3 according to the modification of the embodiment determines the start of a defect in the determination of a defective section (repair welding section) to be repair welded, the non-defect (end of defect) determination criterion can be made stricter in the defect determination of continuous shift regions. That is, when the volume of the shift region (in other words, the volume difference between the appearance shape of the weld bead and the master data) does not satisfy being less than or equal to the second threshold value, the inspection control device 3 determines that the defective section has not ended. Thus, it is possible to determine (detect) a defective section that can further suppress the occurrence of repair omission in the repair welding executed based on the information of the generated defective section.

[0152] Further, as described above, when the volume of the (k + 1)-th shift region is not less than or equal to the second threshold value (an example of a second predetermined value), it is determined whether the volume of the (k + 2)-th shift region continuous with the (k + 1)-th shift region is less than or equal to the second threshold value, and the determination is repeatedly executed until it is determined that the volume of any of the calculated shift regions is less than or equal to the second threshold value. Then, any window constituting the shift region having a volume determined to be less than or equal to the second threshold value is determined as the end point of the defective section. Thereby, the inspection control device 3 according to the modification of the embodiment can continue the defect determination while setting the non-defect (end of defect) determination criterion to the stricter second threshold value until any of the continuous shift regions is determined to be non-defective.

[0153] Further, as described above, when the inspection control device 3 according to the modification of the embodiment determines that the volume of the (N - i + 1)-th shift region is not less than the second threshold value (an example of the second predetermined value), it determines any window constituting the (N - i + 1)-th shift region as the end point of the defect section. Thereby, even if the inspection control device 3 according to the modification of the embodiment determines the (N - i + 1)-th shift region as a defect, it can detect a defect section for repairing the defect in the (N - i + 1)-th shift region PS(N - i + 1) without omission by repair welding.

[0154] Further, as described above, the inspection control device 3 according to the modification of the embodiment determines the barycentric coordinates (for example, the coordinates (X1, Y1, Z1) shown in FIG. 14) of a window (for example, the window ΔV[4] including the start point RCE1 shown in FIG. 14) including the start point of the defect section as the coordinates of the start point (for example, the start point RCE1 shown in FIG. 14). Thereby, the inspection control device 3 according to the modification of the embodiment can calculate the coordinates of the start point for welding each defect section in the repair welding of each defect section executed by the welding robot MC1. Further, since the inspection control device 3 calculates the coordinates based on the barycentric coordinates of the shape mismatch data (point cloud data) in each window, the welding torch 400 can be arranged at a more appropriate position.

[0155] Further, as described above, the inspection control device 3 according to the modification of the embodiment determines the coordinates (for example, the coordinates (X5, Y5, Z5) shown in FIG. 15) of the midpoint between the point (for example, the point SP11 shown in FIG. 15) closest to and the point (for example, the point SP12 shown in FIG. 15) farthest from the welding locus of the welding bead (for example, the operation locus of the welding robot MC1 indicated by the welding direction M3 shown in FIG. 15) among the windows including the start point (for example, the start point RCE3 shown in FIG. 15) as the coordinates of the start point. Thereby, since the inspection control device 3 according to the modification of the embodiment can calculate the coordinates of the start point for welding each defect section in the repair welding of each defect section executed by the welding robot MC1, the welding torch 400 can be arranged at a more appropriate position.

[0156] In addition, as described above, the inspection control device 3 according to the modification of the embodiment determines the barycentric coordinates (for example, the coordinates (X2, Y2, Z2) shown in FIG. 14) of a window (for example, the window ΔV[6] including the end point RCE2 shown in FIG. 14) including the end point of the defective section as the coordinates of the end point (for example, the end point RCE2 shown in FIG. 14). Thereby, the inspection control device 3 according to the modification of the embodiment can calculate the coordinates of the end point for welding each defective section in the repair welding of each defective section executed by the welding robot MC1. Further, since the inspection control device 3 calculates the coordinates based on the barycentric coordinates of the shape mismatch data (point cloud data) in each window, the welding torch 400 can be arranged at a more appropriate position.

[0157] In addition, as described above, the inspection control device 3 according to the modification of the embodiment determines the coordinates of the midpoint between the point (for example, the point SP21 shown in FIG. 15) closest to and the point (for example, the point SP22 shown in FIG. 15) farthest from the welding trajectory of the welding bead (for example, the operating trajectory of the welding robot MC1 indicated by the welding direction M3 shown in FIG. 15) among the windows including the end point (for example, the end point RCE4 shown in FIG. 15) as the coordinates of the end point. Thereby, the inspection control device 3 according to the modification of the embodiment can calculate the coordinates of the end point for welding each defective section in the repair welding of each defective section executed by the welding robot MC1, so that the welding torch 400 can be arranged at a more appropriate position.

[0158] In addition, as described above, the inspection control device 3 according to the modification of the embodiment determines the coordinates of the point (for example, the coordinates (X9, Y9, Z9) shown in FIG. 16) closest to the cutting plane (for example, the cutting plane CS41 corresponding to the window ΔV[4] shown in FIG. 16) of the shape mismatch data corresponding to the window including the start point (for example, the start point RCE5 shown in FIG. 16) of the defective section as the coordinates of the start point. Thereby, the inspection control device 3 according to the modification of the embodiment can calculate the coordinates of the start point for welding each defective section in the repair welding of each defective section executed by the welding robot MC1, so that the welding torch 400 can be arranged at a more appropriate position.

[0159] Further, as described above, the inspection control device 3 according to the modification of the embodiment determines the coordinates of the point (e.g., the coordinates (X10, Y10, Z10) shown in FIG. 16) where the distance to the cut surface of the shape mismatch data (e.g., the cut surface CS42 corresponding to the window ΔV[6] shown in FIG. 16) corresponding to the next window adjacent to the window including the end point of the defective section (e.g., the end point RCE6 shown in FIG. 16) is the closest as the coordinates of the end point. Thereby, since the inspection control device 3 according to the modification of the embodiment can calculate the coordinates of the end point for welding each defective section in the repair welding of each defective section executed by the welding robot MC1, the welding torch 400 can be arranged at a more appropriate position.

[0160] Further, as described above, the inspection control device 3 according to the embodiment and the modification of the embodiment associates the defective section with the volume information in the defective section and outputs it as a condition for repair welding. Thereby, since the inspection control device 3 according to the embodiment and the modification of the embodiment can output the feeding amount of the welding wire 301 required for creating the repair welding program, or the repair welding conditions such as the control parameters (welding current value or welding voltage value) of the power supply device 500 in association with the information of the defective section, it is possible to assist in generating a repair welding program that can more accurately repair the detected defective section.

[0161] As described above, various embodiments have been described with reference to the drawings, but it goes without saying that the present disclosure is not limited to such examples. It is obvious that those skilled in the art can conceive of various change examples, correction examples, substitution examples, addition examples, deletion examples, and equivalent examples within the scope described in the claims, and it is naturally understood that those also belong to the technical scope of the present disclosure. Further, within the scope not departing from the gist of the invention, the components in the above-described various embodiments may be arbitrarily combined.

[0162] Note that this application is based on a Japanese patent application filed on October 28, 2020 (Japanese Patent Application No. 2020-180663), and the content thereof is incorporated herein by reference.

Industrial Applicability

[0163] The present disclosure is useful as a repair weld section detection method and a repair weld section detection device for more accurately detecting a repair weld section of a workpiece produced by the main weld.

Description of Signs

[0164] 1 Host device 2 Robot control device 3 Inspection control device 4 Sensor 10, 20, 30 Communication unit 11, 21, 31 Processor 12, 22, 32 Memory 23 Main weld program creation unit 24 Robot control unit 25 Power control unit 33 Inspection result storage unit 34 Judgment threshold storage unit 35 Shape detection control unit 36 Data processing unit 37 Repair weld program creation unit 100 Welding system 200 Manipulator 300 Wire feeder 301 Welding wire 400 Welding torch 500 Power supply device CS1, CS2, CS41, CS42, CS43, CS44 Cut surface MC1 Welding robot MN1, MN2 Monitor M1, M2, M3 Welding direction RC2, RC3, RCA, RCB, RCC, RCD, RCE, RCF Defective section RC21, RC31, RCA1, RCB1, RCE1, RCE3, RCE5, RCF1, RCF3, RCF5 Starting point RC22, RC32, RCA2, RCB2, RCE2, RCE4, RCE6, RCF2, RCF4, RCF6 End point ST External storage UI1 Input interface

Claims

1. Input input data regarding the weld bead of a workpiece produced by welding, Use the input data and the master data of a good workpiece to perform an inspection determination regarding the shape of the weld bead, Based on the result of the inspection determination, generate shape mismatch data by extracting the locations of shape mismatch of the weld bead, Divide the shape mismatch data into N (N: an integer of 2 or more) windows by equally dividing the shape mismatch data in a direction perpendicular to the welding direction of the weld bead, Set a shift region composed of i (i: an integer of 1 or more) consecutive windows out of the N windows, Calculate the volumes of (N - i + 1) shift regions obtained by shifting the i windows constituting the shift region one by one in the welding direction, Determine that a shift region having a volume equal to or greater than a predetermined value among the volumes of the (N - i + 1) calculated shift regions is a defective section of the weld bead, A repair welding section detection method.

2. The calculation of the volumes of the (N - i + 1) shift regions and the determination process of the defective section are sequentially executed (N - i + 1) times along the welding direction, The repair welding section detection method according to Claim 1.

3. Determine that the first window among the i windows included in the shift region determined to be the defective section is the start point of the defective section, and determine that the i-th window is the end point of the defective section, The repair welding section detection method according to Claim 1.

4. When two or more consecutive shift regions are determined to be the defective section, determine that the first window among the i windows constituting the shift region first determined to be the defective section among the two or more consecutive shift regions is the start point of the defective section, and determine that the i-th window among the i windows included in the shift region finally determined to be the defective section is the end point of the defective section, The repair welding section detection method according to Claim 2.

5. When the first shift region among the (N - i + 1) shift regions is determined to be the defective section, determine that the first window among the i windows constituting the first shift region is the start point of the defective section, The repair welding section detection method according to Claim 2.

6. When the (N - i + 1)-th shift region among the (N - i + 1) shift regions is determined to be the defective section, determine that the i-th window among the i windows constituting the (N - i + 1)-th shift region is the end point of the defective section, The repair welding section detection method according to claim 2.

7. When it is determined that two or more consecutive shift regions are the defect section, the central position of the shift region first determined to be the defect section is determined as the start point of the defect section, and the central position of the shift region finally determined to be the defect section is determined as the end point. The repair welding section detection method according to claim 2.

8. When it is determined that any k-th (k: an integer of 1 or more) shift region among the (N - i + 1) shift regions is the defect section, any window included in this shift region is set as the start point of the defect section, and it is determined whether the volume of the (k + 1)-th shift region continuous with the shift region is less than or equal to a second predetermined value smaller than the predetermined value. When the volume of the (k + 1)-th shift region is less than or equal to the second predetermined value, any window constituting the (k + 1)-th shift region is determined as the end point of the defect section. The repair welding section detection method according to claim 2.

9. When the volume of the (k + 1)-th shift region is not less than or equal to the second predetermined value, it is determined whether the volume of the (k + 2)-th shift region continuous with the (k + 1)-th shift region is less than or equal to the second predetermined value. The determination is repeatedly executed until it is determined that the volume of any calculated shift region is less than or equal to the second predetermined value, and any window constituting the shift region having the volume determined to be less than or equal to the second predetermined value is determined as the end point of the defect section. The repair welding section detection method according to claim 8.

10. When it is determined by the determination that the volume of the (N - i + 1)-th shift region is not less than or equal to the second predetermined value, any window constituting the (N - i + 1)-th shift region is determined as the end point of the defect section. The repair welding section detection method according to claim 9.

11. The barycentric coordinates of the window including the start point of the defect section are determined as the coordinates of the start point. The repair welding section detection method according to any one of claims 3 to 5 and 7.

12. The coordinates of the midpoint between the point closest to and the point farthest from the welding trajectory of the welding bead among the windows including the start point are determined as the coordinates of the start point. The repair welding section detection method according to claim 11.

13. The barycentric coordinates of the window including the end point of the defect section are determined as the coordinates of the end point. The repair welding section detection method according to any one of claims 3 to 4 and 6 to 10.

14. Determine the coordinates of the midpoint between the point closest to and the point farthest from the welding bead's welding track among the windows including the end point as the coordinates of the end point. The repair welding section detection method according to claim 13.

15. Determine the coordinates of the start point as the coordinates of the point closest to the cutting plane of the shape mismatch data corresponding to the window including the start point of the defect section. The repair welding section detection method according to any one of claims 3 to 5 and 7.

16. Determine the coordinates of the end point as the coordinates of the point closest to the cutting plane of the shape mismatch data corresponding to the window adjacent to the next window including the end point of the defect section. The repair welding section detection method according to any one of claims 3 to 4 and 7 to 10.

17. Associate the defect section with the volume information in the defect section and output it as the conditions for repair welding. The repair welding section detection method according to claim 1.

18. An input unit for inputting input data regarding the welding bead of a workpiece produced by welding; A determination unit for performing an inspection determination regarding the shape of the welding bead using the input data and the master data of a non-defective workpiece; A data generation unit for generating shape mismatch data by extracting the shape mismatch portions of the welding bead based on the inspection determination result of the determination unit; Dividing the shape mismatch data into N (N: an integer of 2 or more) windows equally in a direction perpendicular to the welding direction of the welding bead, setting a shift region composed of i (i: an integer of 1 or more) consecutive windows among each of the windows, and calculating the volume of each of the (N - i + 1) shift regions obtained by shifting the i windows constituting the shift region one by one in the welding direction; A generation unit that determines that a shift region having a volume equal to or greater than a predetermined value among the volumes of the calculated (N - i + 1) shift regions is a defect section of the welding bead, and generates information on the defect section. A repair welding section detection device.

Images