Robot teaching system and robot teaching method

Abstract

To correct a teaching attitude of a taught teaching point to an attitude more suitable for a welding robot.SOLUTION: A robot teaching system stores a three-dimensional model corresponding to at least a part of a robot or a welding torch or a teaching member, is configured to be capable of being mounted on a worker, on the basis of the three-dimensional model and operation screen data, outputs a display image to a display device for displaying an image so that the image is superposed on the image of the actual environment or the actual environment itself, detects aerial operation of the worker in the air or teaching member operation using the teaching member, and generates and outputs a display image for displaying a three-dimensional model in an attitude corresponding to the attitude of the robot satisfying a predetermined constraint condition, on the basis of a predetermined constraint condition of the robot.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a robot teaching system and a robot teaching method. [Background technology]

[0002] Patent Document 1 discloses a welding system including a welding robot equipped with a torch and a welding robot control program creation device. The welding system acquires position information of the welding start point and welding end point of welding on a workpiece, and posture information that can identify the posture of the torch relative to the welding line at a welding teaching point on the welding line connecting the welding start point and welding end point, creates a welding robot control program for welding from the welding start point to the welding end point based on the position information and posture information, and welds the workpiece based on the welding robot control program. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2021 / 251087 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a robot teaching system and a robot teaching method that correct the teaching posture of a taught teaching point to a posture more suitable for a welding robot. [Means for solving the problem]

[0005] The present disclosure provides a display device configured to be wearable by a worker and displaying an image by superimposing it on an image of the real environment or the real environment itself; a positional relationship acquisition unit that acquires a relative positional relationship between the real environment, the teaching member, and the display device; and a display device that acquires a predetermined position with respect to the display device based on the relative positional relationship and the three-dimensional model. a detection unit that detects an aerial operation, which is an operation performed by the worker in the air away from the display device on the 3D model displayed on the display device, or a teaching member operation performed by the worker using the teaching member, wherein the image generation unit generates and outputs the display image for displaying the 3D model in a posture corresponding to the posture of the robot that satisfies predetermined constraint conditions, based on the aerial operation or the teaching member operation and predetermined constraint conditions of the robot.

[0006] The present disclosure also provides a robot teaching method executed by at least one computer, which stores a three-dimensional model corresponding to at least a part of a robot or a welding torch used for welding that exists in a real environment, or a teaching member used to teach the robot, teaching data for the robot, and teaching point data corresponding to teaching points used to display the teaching data, obtains a relative positional relationship between the real environment, the teaching member, and a display device that is configured to be wearable by a worker and that displays an image of the real environment or the real environment itself by superimposing it, and displays the image of the real environment or the real environment itself based on the relative positional relationship and the three-dimensional model. a display image for displaying the three-dimensional model so that it has a predetermined positional relationship with a display device, outputting the display image to the display device, detecting an aerial operation, which is an operation performed by the worker in the air away from the display device on the three-dimensional model displayed on the display device, or a teaching member operation performed by the worker using the teaching member, and generating and outputting the display image for displaying the three-dimensional model in a posture corresponding to the posture of the robot that satisfies the predetermined constraint condition, based on the aerial operation or the teaching member operation and predetermined constraint conditions of the robot. [Effects of the Invention]

[0007] According to the present disclosure, the teaching posture of the teaching point that has been taught can be corrected to a posture that is more suitable for the welding robot. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing an example of a welding teaching system according to an embodiment. [Figure 2] FIG. 1 shows an example of the internal configuration of an MR device and a processing device. [Figure 3] FIG. 1 is a sequence diagram illustrating an example of an operation procedure of an MR device according to an embodiment. [Figure 4] Diagram explaining an example of attitude correction around the TX axis [Figure 5] 10 is a flowchart illustrating a first example of a procedure for correcting the welding posture of an MR device according to an embodiment. [Figure 6] 10 is a flowchart illustrating a second example of a procedure for correcting the welding posture of the MR device according to the embodiment. [Figure 7] 10 is a flowchart illustrating a second example of a procedure for correcting the welding posture of the MR device according to the embodiment. [Figure 8] FIG. 10 is a diagram illustrating an example of a plurality of welding positions before correction. [Figure 9] FIG. 10 is a diagram illustrating an example of a plurality of welding positions after correction. [Figure 10] 10 is a flowchart illustrating a third example of a procedure for correcting the welding posture of an MR device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] (Background to this disclosure) Recently, there has been a teaching method that uses an Augmented Reality (AR) device to read and teach the position of a teaching point taught by an operator and the posture of a teaching tool at the teaching point, as in the welding system described in Patent Document 1. Compared to using a general offline teaching system such as a teach pendant, this teaching method allows the operator to directly teach the teaching point, thereby shortening the time required to teach the teaching point. However, the posture taught by the operator may be, for example, a posture that makes high-speed operation difficult or a posture that is prone to twisting the welding wire, and may not be a posture suitable for operating a welding robot that performs welding.

[0010] Therefore, in the following embodiments, a robot teaching system and a robot teaching method for correcting the teaching posture of a teaching point to a posture more suitable for a welding robot will be described.

[0011] Hereinafter, with reference to the drawings as appropriate, detailed descriptions of embodiments specifically disclosing a robot teaching system and a robot teaching method according to the present disclosure will be provided. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters or redundant descriptions of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure and are not intended to limit the subject matter recited in the claims.

[0012] <Welding teaching system overview> First, a welding teaching system 100 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing an example of welding teaching system 100 according to an embodiment. Note that welding teaching system 100 shown in Fig. 1 is an example and is not limited to this.

[0013] Welding teaching system 100 corrects the posture of the teaching point taught by the worker to a posture more suitable for the operation of welding robot RB that performs welding operation based on this teaching point. Welding teaching system 100 generates a virtual welding torch VTC having the corrected posture, and generates a mixed reality image in which the image of the generated virtual welding torch VTC is superimposed on a captured image of the real world, and visualizes it for the worker.

[0014] In the following description, an example will be described in which the posture is an angle (i.e., twist angle) about the TX axis, which is along the direction in which the welding wire WW is fed from the welding torch TC toward the welding point (i.e., the teaching point) on the workpiece Wk. However, the correctable posture (angle) is not limited to the angle (twist angle) about the TX axis. The correctable posture (angle) may be, for example, an angle about a direction along the movement trajectory of the tip of the welding torch TC as the rotation axis (i.e., tilt angle), or an angle about a direction perpendicular to the movement trajectory of the tip of the welding torch TC and along the surface of the workpiece Wk as the rotation axis (i.e., forward / rearward advance angle).

[0015] In addition, in the following explanation, we will explain an example in which the work displayed in the mixed reality space is an actual work Wk that exists in the real world, but it may also be a virtual work constructed based on 3D model data, etc.

[0016] Furthermore, the teaching points taught in this disclosure may include not only welding points for welding the workpiece Wk, but also approach points for approaching the workpiece Wk, avoidance points for avoiding obstacles, free-running points for free-running the welding torch TC, or departure points for moving away from the workpiece Wk.

[0017] The welding teaching system 100 includes at least an MR device DV. The welding teaching system 100 shown in FIG. 1 includes a workpiece Wk, an MR device DV, and a processing device P1. Note that the workpiece Wk shown in FIG. 1 is a real-world (actual) workpiece Wk, but the workpiece Wk may be a virtual workpiece constructed based on a 3D model of the workpiece Wk. Furthermore, if the MR device DV can realize the functions of the processing device P1, the processing device P1 may be omitted.

[0018] The MR device DV is a so-called head-mounted display, and is connected to the processing device P1 so as to be able to communicate data with it. The MR device DV is worn on the head of the worker, and forms a virtual space in which images of virtual production equipment (for example, a virtual workpiece, a virtual welding robot VRB, a virtual welding torch VTC, or a virtual jig) are superimposed on a captured image of a real space corresponding to the worker's field of vision, and displays the virtual space on the display unit 13, thereby visualizing the virtual space for the worker.

[0019] The welding robot RB is a six-axis articulated robot with a welding torch TC attached to the tip of its wrist. The welding robot RB comprises, from the installation surface on which the welding robot RB is installed toward the tip (wrist), a base, an upper arm, a forearm, and a wrist. The welding robot RB drives the upper arm, the forearm, the wrist, or the welding torch TC by rotating the first axis, the second axis, the third axis, the fourth axis, the fifth axis, or the sixth axis. Note that the number of joint axes (joints) provided in the welding robot RB is not limited to this.

[0020] The welding robot RB has a welding torch TC and a wire feeder WW1, and is a robot that performs welding by feeding the welding wire WW from the welding torch TC to a welding point on the workpiece Wk using the wire feeder WW1. The welding robot RB is controlled by a robot controller (not shown) that is connected to a processing device P1 (described later) so as to be capable of data communication, and performs the taught welding operations.

[0021] The MR device DV generates a virtual welding torch VTC having a taught posture at the position of the taught teaching point based on information including the position and posture of the taught teaching point (hereinafter referred to as "teaching information"). The MR device DV generates a teaching image SC11 (see FIG. 4) in which the generated virtual welding torch VTC is superimposed at the position of the teaching point on the workpiece Wk shown in the captured image captured by the camera 15, and displays the teaching image SC11 on the display unit 13, thereby visualizing the posture of the welding torch TC at the taught teaching point.

[0022] Furthermore, the MR device DV automatically corrects the posture of the teaching point that has already been taught using each correction method described below. When the MR device DV receives an instruction from the operator to automatically correct the posture, it automatically corrects the posture of each teaching point to a posture that is more suitable for the welding robot RB to which the teaching point is taught. The MR device DV updates the posture of the teaching point to the corrected posture, and generates and displays a corrected image SC12 (see FIG. 4) in which a virtual welding torch VTC corresponding to the corrected posture is superimposed on the captured image. Furthermore, the MR device DV generates teaching information including information on the corrected posture and transmits it to the processing device P1.

[0023] The processing device P1 is connected between the MR device DV and the robot controller so that data communication can be performed between them. The processing device P1 records each piece of taught teaching information (i.e., information on the position (three-dimensional) and posture (three-dimensional) of the teaching point). The processing device P1 transmits the recorded posture to the MR device DV, which executes a correction process for the posture, acquires the corrected teaching information transmitted from the MR device DV, and updates (records) the recorded teaching information before correction to the corrected teaching information. The processing device P1 also executes the teaching process for each teaching point by transmitting the position and posture information of the teaching point to the robot controller, which controls and drives the welding robot RB in the real world.

[0024] Next, an example of the internal configuration of the MR device DV and the processing device P1 will be described with reference to Fig. 2. Fig. 2 is a diagram showing an example of the internal configuration of the MR device DV and the processing device P1.

[0025] The MR device DV includes a communication unit 10, a processor 11, a memory 12, a display unit 13, a depth sensor 14, and a camera 15.

[0026] The communication unit 10 is connected to the teaching tool TL and the processing device P1 so as to be able to communicate wirelessly or via wires, and transmits and receives data. The communication unit 10 outputs various data transmitted from the teaching tool TL and the processing device P1 to the processor 11. The communication unit 10 transmits various data output from the processor 11 to the processing device P1. The wireless communication here refers to communication via a wireless local area network (LAN) such as Wi-Fi (registered trademark). When the processing device P1 is omitted from the welding teaching system 100, the communication unit 10 is connected to the robot controller so as to be able to communicate data.

[0027] Processor 11 is configured using, for example, a central processing unit (hereinafter referred to as "CPU") or a field programmable gate array (hereinafter referred to as "FPGA"), and performs various processes and controls in cooperation with memory 12. Specifically, processor 11 references programs and data stored in memory 12 and executes the programs to realize functions such as correcting the posture of a taught teaching point and generating a virtual welding torch VTC corresponding to teaching information to generate a teaching image or a corrected image. When processing device P1 is omitted from welding teaching system 100, processor 11 is configured to be able to realize functions similar to those of processor 21 of processing device P1.

[0028] Processor 11 calculates the relative positional relationship in three-dimensional space for each of the recognized or detected objects and production equipment based on the objects detected by depth sensor 14, the captured images captured by camera 15, and the 3D model data of various production equipment stored in memory 12. Specifically, processor 11 calculates the relative positional relationship in three-dimensional space for each of the coordinate system and position of workpiece Wk (virtual workpiece), the coordinate system and position of welding robot RB (virtual welding robot VRB), etc. As a result, processor 11 can generate an image of a virtual space in which the virtual production equipment is superimposed on a captured image of the real world, and display the image on display unit 13. As a result, processor 11 can also generate teaching information to be taught to real-world welding robot RB that welds workpiece Wk.

[0029] The memory 12 includes, for example, a random access memory (hereinafter referred to as "RAM") as a work memory used when executing each process of the processor 11, and a read only memory (hereinafter referred to as "ROM") that stores programs and data that define the operations of the processor 11. The RAM temporarily stores data or information generated or acquired by the processor 11. The ROM stores programs that define the operations of the processor 11.

[0030] Memory 12 stores a 3D model of at least a part of the welding robot RB or welding torch TC that welds the workpiece Wk, a 3D model of various production facilities, information about the welding robot RB, pre-correction or corrected teaching information, etc. Memory 12 also stores various data generated by processor 11 and displayed on display unit 13.

[0031] The information relating to the welding robot RB here is, for example, information relating to the coordinate system of the welding robot RB, the range of motion (movable range) of each axis of the welding robot RB, the posture (movable range) that reduces the operating load of each axis of the welding robot RB or the posture (movable range) that allows high-speed operation, or the posture that can further suppress twisting of the welding wire WW.

[0032] The display unit 13 is configured using, for example, a Liquid Crystal Display (LCD) or an organic electroluminescence (EL). The display unit 13 displays the real world itself, or a teaching image or a correction image of a virtual space in which virtual production equipment is superimposed on the real world. The display unit 13 realizes mixed reality by, for example, displaying an image of the virtual space (e.g., a teaching image) in which virtual production equipment generated by the processor 11 is superimposed on an image of the real world captured by the camera 15.

[0033] The depth sensor 14 is a sensor that measures the distance between the MR device DV and an object in the real world and recognizes the three-dimensional shape of the object in the real world (for example, a workpiece Wk, a welding robot RB, a jig, etc.). The depth sensor 14 outputs the recognition result to the processor 11.

[0034] The camera 15 captures an image of an area (real world) corresponding to the field of view of the worker wearing the MR device DV. The camera 15 outputs the captured image to the processor 11.

[0035] The processing device P1 includes a communication unit 20, a processor 21, and a memory 22.

[0036] The communication unit 20 is connected to the MR device DV and the robot controller so as to be able to communicate wirelessly or via wires, and transmits and receives data. The communication unit 20 outputs various data transmitted from the MR device DV to the processor 21. The communication unit 20 transmits various data output from the processor 21 to the MR device DV or the robot controller. The wireless communication here refers to communication via a wireless LAN such as Wi-Fi (registered trademark).

[0037] Processor 21 is configured using, for example, a CPU or FPGA, and performs various processes and controls in cooperation with memory 22. Specifically, processor 21 references the programs and data stored in memory 22 and executes the programs to realize various functions for generating a welding teaching program.

[0038] Memory 22 includes, for example, a RAM as a work memory used when each process of processor 21 is executed, and a ROM that stores programs and data defining the respective operations of processor 21. In the RAM, data or information generated or acquired by processor 21 is temporarily stored. In the ROM, a program defining the operation of processor 21 is written. Memory 22 includes a teaching information recording unit 221 and a work information recording unit 222. Note that the teaching information recording unit 221 and the work information recording unit 222 may be recorded in the memory 12 of the MR device DV. Memory 22 records a 3D model of the welding robot RB, information regarding the coordinate system of the welding robot, and information regarding the welding robot RB, etc.

[0039] The teaching information recording unit 221 records each of a plurality of teaching information for each work Wk. The work information recording unit 222 records a 3D model of the work Wk.

[0040] <Operation Procedure of MR Device> Next, referring to FIG. 3, an example of the operation procedure of the MR device DV will be described. FIG. 3 is a sequence diagram showing an example of the operation procedure of the MR device DV in the embodiment.

[0041] The operator teaches the position and orientation of the teaching point using a teaching tool TL regarded as a welding torch TC (St11). The operator performs a teaching operation of the teaching information by pressing (selecting) a physical button provided on the teaching tool TL or a virtual button displayed on the display unit 13. Note that the number of teaching points taught here may be one or a plurality. Also, the teaching of the teaching points may have been completed in advance.

[0042] The MR device DV adds (stores) the teaching point taught by the operator operation as a new teaching point of the work Wk (St12).

[0043] Based on the taught teaching information, the MR device DV generates a teaching image SC11 (see Figure 4) by generating and superimposing a virtual welding torch VTC corresponding to the taught position and posture on the captured image captured by the camera 15, and displays it on the display unit 13 (St13).

[0044] The operator issues a correction instruction to automatically correct the posture of the already taught teaching point (St14). The correction instruction issued here may be received by a button on the teaching tool TL or a virtual correction button displayed on the display unit 13.

[0045] When the MR device DV acquires the correction instruction, it automatically corrects the posture w of the taught teaching point to a posture more suitable for the operation of the welding robot RB based on the information about the welding robot RB (St15A, St15B, St15C). Details of the processes of steps St15A, St15B, and St15C will be described later.

[0046] Specifically, the MR device DV acquires teaching information (x, y, z, u, v, w). Here, the teaching information (x, y, z) is the robot coordinate system (XYZ coordinate system, see Figure 1) of the welding robot RB and indicates the position of the tip of the welding torch TC at the teaching point. The teaching information (u, v, w) is the coordinate system of the wrist axis of the welding robot RB, i.e., the torch coordinate system (UVW coordinate system, see Figure 1) of the welding torch TC. The teaching information (u, v, w) indicates the posture of the welding torch TC at the teaching point. The posture u indicates the rotation angle around an axis parallel to the Z axis that maintains the posture v and includes the teaching point (i.e., the forward / backward advance angle of the welding torch TC). The posture v indicates the tilt angle of the welding torch TC with respect to the weld line. The posture w indicates the angle (i.e., the twist angle) around the wrist axis (i.e., the TX axis described later) of the welding robot RB to which the welding torch TC is attached.

[0047] Based on information about the welding robot RB, the MR device DV corrects the posture w (angle around the TX axis) of the pre-correction teaching information (x, y, z, u, v, w) to posture (w + Δw) and acquires the corrected teaching information (x, y, z, u, v, w + Δw).

[0048] The MR device DV updates the attitude w included in the teaching information to the corrected attitude (w+Δw) and stores it (St16), and generates a virtual welding torch VTC having the corrected attitude (w+Δw). The MR device DV generates a corrected image SC12 (see FIG. 4) by superimposing the generated virtual welding torch VTC on the captured image, and displays it on the display unit 13 (St17).

[0049] As described above, the MR device DV in the embodiment can automatically correct the taught posture to a posture more suitable for the operation of the welding robot RB based on information about the welding robot RB. As a result, the MR device DV can generate teaching information that improves the operation efficiency of the welding robot RB, thereby improving productivity in the production of the workpiece Wk using the corrected teaching information and reducing the operating load of the welding robot RB during welding. In addition, the MR device DV can support the teaching work by the worker.

[0050] Next, an example of attitude correction around the TX axis will be described with reference to Fig. 4. Fig. 4 is a diagram showing an example of attitude correction around the TX axis.

[0051] The teaching image SC11 is an image in which the virtual welding torch VTC11 having the posture before the posture correction is visualized. The MR device DV calculates the TX axis at this teaching point based on the posture before the posture correction. As shown in the AA arrow view, the MR device DV sets the calculated TX axis as the reference angle (Δw=0 (zero)°).

[0052] The MR device DV receives an instruction to correct the posture from the worker. In the example shown in Fig. 4, the MR device DV executes posture correction based on information about the welding robot RB, by rotating the posture before the posture correction (the posture shown on the virtual teaching tool VTL11) by 30° around the TX axis to make it a posture suitable for the operation of the welding robot RB.

[0053] As shown in the view seen from the arrow AA, the MR device DV corrects the attitude of the virtual welding torch VTC11 from Δw=0 (zero)° (i.e., the reference angle) to an attitude Δw=30°, which is obtained by rotating the attitude of the virtual welding torch VTC11 by 30° around the TX axis. The MR device DV generates a virtual welding torch VTC12 corresponding to the corrected attitude. The MR device DV generates a corrected image SC12 by superimposing the generated virtual welding torch VTC12 on the captured image, and displays the image on the display unit 13.

[0054] Various posture correction methods will be described below. The MR device DV accepts a setting operation from the operator to determine which posture correction method to apply, and corrects the posture w using the set correction method.

[0055] <First welding position correction procedure> First, a method for correcting the posture based on the operable range of the welding robot RB (hereinafter referred to as "correction method 1-1") and a method for correcting the posture based on the manipulability of the welding robot RB (hereinafter referred to as "correction method 1-2") will be described with reference to Fig. 5. Fig. 5 is a flowchart for explaining a first example of a procedure for correcting the welding posture of the MR device DV in the embodiment. Note that the first example of a procedure for correcting the welding posture described in Fig. 5 is a process executed in step St15A shown in Fig. 3.

[0056] The MR device DV generates teaching information for the welding robot RB based on the teaching information that has been taught (St111). The MR device DV determines whether or not there is a correction instruction from the operator to instruct automatic correction of the teaching point (St112).

[0057] When it is determined in step St112 that a correction instruction is given (St112, YES), the MR device DV corrects the posture w of each teaching point based on the information about the welding robot RB (St113).

[0058] On the other hand, if it is determined in step St112 that there is no correction instruction (St112, NO), the MR device DV omits the correction process of the posture w at the teaching point, generates a virtual welding torch VTC11 having the posture w before correction, and displays it in the mixed reality space (St114). The mixed reality space displayed here is, for example, the teaching image SC11.

[0059] After executing the correction process of the posture w at the teaching point in step St113, the MR device DV generates a virtual welding torch VTC12 having the corrected posture (w+Δw) and displays it in the mixed reality space (St114). Note that the displayed mixed reality space is, for example, the corrected image SC12.

[0060] <Correction method 1-1> Here, the correction method 1-1 executed in step St113 will be described in detail.

[0061] The MR device DV receives the acquired teaching information (x, y, z, u, v, w) T Based on this, the posture θ of the welding robot RB when the posture corresponding to this teaching information is realized r =(θ1,θ2,θ3,θ4,θ5,θ6) T Here, angles θ1 to θ6 are the rotation angles of the first to sixth axes of the welding robot RB, respectively.

[0062] The MR device DV acquires information on the operable range (i.e., range of motion) of each axis based on information on the welding robot RB. The MR device DV normalizes each angle θ1 to θ6 with respect to the operable range of each axis using (Equation 1) and (Equation 2), respectively, and calculates an evaluation value vector B for evaluating the stability of the posture of the welding robot RB. The MR device DV then calculates the posture θ of the welding robot RB that minimizes the evaluation value S, which is obtained by converting the calculated evaluation value vector B into a real value using a certain function. r The MR device DV calculates the calculated posture θ of the welding robot RB. r Based on this, the posture (rotation angle) Δw around the TX axis is calculated, and the teaching information (x, y, z, u, v, w + Δw) T Correct it to:

[0063] Here, we will explain each of (Formula 1) to (Formula 3). Note that each of (Formula 1) to (Formula 2) shows, as an example, only a formula for calculating the evaluation parameter b1 for the angle θ1 of the first axis, but since the evaluation parameters b2 to b6 for the other angles θ2 to θ6 can be calculated in the same way, explanations will be omitted here.

[0064] In (Equation 1), the angle θ 1min indicates the minimum value of the movable range of the first axis. Angle θ 1max indicates the maximum value of the first axis's operable range. (Equation 1) indicates the maximum value of the first axis' operable range (θ 1min <θ1<θ 1max ) is a calculation formula for calculating the position A1 of the angle θ1 with respect to the

[0065]

number

[0066] (Equation 2) is the range of motion of the first axis (θ 1min <θ1<θ 1max ) and calculates an evaluation parameter b1 for calculating an evaluation value B.

[0067]

number

[0068] (Equation 3) is a calculation formula for calculating an evaluation value vector B indicating that the posture w of the teaching point for the operational range of the welding robot RB is a posture suitable for the operation of the welding robot RB, based on the evaluation parameters b1 to b6 for each of the operational ranges of the first to sixth axes.

[0069]

number

[0070] The MR device DV calculates an evaluation value S by converting the evaluation value vector B into a real value using a certain function. For example, the sum of squares of the evaluation value vector B |B| 2 If the evaluation value S is S, then S = 0 (zero) is the median value of the operable range of the welding robot RB, and |B| 2 The larger the value, the closer it is to the minimum / maximum value of the operable range of the welding robot RB.

[0071] Through the above procedure, the MR device DV determines the posture θ of the welding robot RB that minimizes the evaluation value S. r The MR device DV determines the posture θ of the welding robot RB that minimizes the evaluation value S. r The MR device DV calculates the angle Δw (amount of rotation) around the TX axis based on the teaching information (x, y, z, u, v, w). T The teaching information (x, y, z, u, v, w + Δw) T Correct it to:

[0072] The evaluation value S is calculated based on information about the welding robot RB (for example, differences in the size of the operable range of each axis) and is calculated as B abs =(|b1|,|b2|,|b3|,|b4|,|b5|,|b6|) T Or B with squared components sq =(b1 2 ,b2 2 ,b32 ,b4 2 ,b5 2 ,b6 2 ) T weight ω=(ω1,ω2,ω3,ω4,ω5,ω6) T Weighting may be performed using B abs and B sq The evaluation value ω obtained by weighting T B abs and the evaluation value ω T B sq The calculation formula is shown in (Formula 4).

[0073]

number

[0074] In such a case, the MR device DV is calculated by the weighted evaluation value ω T B abs or the evaluation value ω T B sq The posture θ of the welding robot RB that minimizes r may be determined.

[0075] As described above, by executing correction method 1-1, the MR device DV in the embodiment can automatically correct the posture of the taught point taught from the viewpoint of the operable range of the welding robot RB to a posture more suitable for the operation of the welding robot RB. As a result, the MR device DV generates teaching information that improves the operational efficiency of the welding robot RB, thereby improving productivity in the production of the workpiece Wk using the corrected teaching information and reducing the operational load of the welding robot RB during welding.

[0076] <Correction method 1-2> Next, the correction method 1-2 executed in step St113 will be described in detail.

[0077] The MR device DV receives the acquired teaching information (x, y, z, u, v, w) T Based on this, the posture θ of the welding robot RB when the posture corresponding to this teaching information is realizedr =(θ1,θ2,θ3,θ4,θ5,θ6) T are calculated respectively.

[0078] The MR device DV acquires information on the manipulability of the welding robot RB, that is, information on an index indicating the degree of freedom in manipulating the position and posture of the welding robot RB, based on information on the welding robot RB.

[0079] The MR device DV uses (Equation 5) to calculate the Jacobian matrix J(θ r The MR device DV calculates the calculated Jacobian matrix J(θ r ) based on the evaluation value T, the posture θ of the welding robot RB that maximizes the evaluation value T r The MR device DV calculates the calculated posture θ of the welding robot RB. r Based on this, the posture (rotation angle) Δw around the TX axis is calculated, and the teaching information (x, y, z, u, v, w + Δw) T Correct it to:

[0080] Here, we will explain each of (Equation 5) to (Equation 6). (Equation 5) is a Jacobian matrix J(θ r ) is the formula for calculating

[0081]

number

[0082] (Equation 6) is the Jacobian matrix J(θ r ) and the Jacobian matrix J(θ r ) transpose matrix J(θ r ) T This is a calculation formula for calculating an evaluation value T that quantitatively evaluates the manipulability of the welding robot RB based on the above.

[0083]

number

[0084] The MR device DV determines the posture θ of the welding robot RB that maximizes the calculated evaluation value T. r The MR device DV determines the posture θ of the welding robot RB that maximizes the evaluation value T from the angle w of the wrist axis (i.e., TX axis) of the welding robot RB before correction. r Based on this, the posture (rotation angle) Δw around the TX axis is calculated, and the teaching information (x, y, z, u, v, w + Δw) T Correct it to:

[0085] As described above, by executing correction method 1-2, the MR device DV in the embodiment can automatically correct the posture of the taught point taught from the viewpoint of the manipulability of the welding robot RB to a posture more suitable for the operation of the welding robot RB. This allows the MR device DV to reduce the operational load of the welding robot RB during welding and prevent the taught posture from becoming a singular point of the welding robot RB.

[0086] <Second welding position correction procedure> Next, with reference to Fig. 6 to Fig. 8, a method for correcting the posture based on the maximum angular velocity of each axis of the welding robot RB (hereinafter referred to as "correction method 2-1") and a method for correcting the posture based on minimizing the takt time of the welding robot RB (hereinafter referred to as "correction method 2-2") will be described. Fig. 6 is a flowchart for explaining a second example of the procedure for correcting the welding posture of the MR device DV in the embodiment. Fig. 7 is a flowchart for explaining a second example of the procedure for correcting the welding posture of the MR device DV in the embodiment.

[0087] The second example of the welding posture correction procedure described in each of Figures 6 and 7 is the processing executed in step St15B shown in Figure 3. The second example of the welding posture correction procedure described in each of Figures 6 and 7 shows, as an example, an example of the correction procedure when correction method 2-1 is applied. The second example of the welding posture correction procedure when correction method 2-2 is applied is a correction procedure in which the "posture in which the maximum angular velocity of each axis of the welding robot RB is minimized" in Figures 6 and 7 is replaced with "the posture in which the takt time of the welding robot RB operating between two teaching points is minimized."

[0088] The MR device DV accepts a selection operation of the i (i: an integer equal to or greater than 1, k → i)-th teaching point set as one of the basic postures among N (N: an integer equal to or greater than 1) teaching points already taught by the operator. The MR device DV converts the posture of the selected i (i: an integer equal to or greater than 1, k → i)-th teaching point into a basic posture (i.e., posture Δw i =0 (zero)° (St211).

[0089] The MR device DV determines whether the i-th teaching point set in the basic posture is the first teaching point (St212).

[0090] In step St212, when it is determined that the i-th teaching point set in the basic posture is not the first teaching point (St212, NO), the MR device DV determines the posture Δw of the (i-1)-th teaching point. (i-1) is set to the basic position (=0 (zero) degrees) (St213).

[0091] The MR device DV is the posture w of the i-th teaching point. i and the posture of the (i-1)th teaching point w (i-1) Based on this, the maximum angular velocity ω of each axis of the welding robot RB moving between the i-th teaching point and the (i-1)-th teaching point is (i-1)i The orientation of the (i-1)th teaching point (w (i-1) +Δw (i-1) ) is calculated (Step 214).

[0092] The MR device DV is the orientation w of the (i-1)th teaching point in the teaching information. (i-1) The maximum angular velocity of each axis of the welding robot RB is ω (i-1)i The orientation of the (i-1)th teaching point (w (i-1) +Δw (i-1) ) and correct (memorize) it (St215).

[0093] The MR device DV decrements the value of i (i=i-1) (St216), and determines whether the decremented i is i=1 (St217).

[0094] If the MR device DV determines in step St217 that the decremented i is i=1 (St217, YES), it ends the processing of steps St214 to St216 and proceeds to processing of step St218.

[0095] On the other hand, if the MR device DV determines in step St217 that the decremented i is not i=1 (St217, NO), it returns to the processing of step St214 and determines the attitude w of the (i-1)th teaching point. (i-1) Execute the corrective action.

[0096] Furthermore, if the MR device DV determines in step St212 that the i-th teaching point set in the basic posture is the first teaching point (St212, YES), the MR device DV proceeds to the processing of step St218.

[0097] The MR device DV determines whether the k-th teaching point set in the basic posture is the N-th teaching point (that is, the last teaching point) (St218).

[0098] In step St218, if it is determined that the i (i: an integer equal to or greater than 1, k → i)-th teaching point set in the basic posture is not the N-th teaching point (St212, NO), the MR device DV determines the posture Δw of the (i+1)-th teaching point. (i+1) Set to the basic position (=0°) (St219).

[0099] The MR device DV is the posture w of the i-th teaching point. i and the (i+1)th teaching point posture w (i+1) Based on this, the maximum angular velocity ω of each axis of the welding robot RB moving between the i-th teaching point and the (i+1)-th teaching point is (i+1)i The orientation w of the (i+1)th teaching point that minimizes (i+1) Calculate (St220).

[0100] The MR device DV is the orientation w of the (i+1)th teaching point in the teaching information. (i+1) The maximum angular velocity of each axis of the welding robot RB is ω (i+1)i The orientation of the (i+1)th teaching point (w (i+1) +Δw (i+1) ) and correct (memorize) it (St221).

[0101] The MR device DV increments the value of i (i=i+1) (St222), and determines whether the incremented i is i=N (St223).

[0102] When the MR device DV determines in step St223 that the incremented i is i=N (St223, YES), it ends the processing of steps St220 to St222 and proceeds to processing of step St224.

[0103] On the other hand, if the MR device DV determines in step St223 that the incremented i is not i=N (St223, NO), it returns to the processing of step St220 and determines the posture w of the (i+1)th teaching point. (i+1) Execute the corrective action.

[0104] Furthermore, if the MR device DV determines in step St218 that the i-th teaching point set in the basic posture is the N-th teaching point (St218, YES), the MR device DV proceeds to the processing of step St224.

[0105] The MR device DV determines whether or not the operator has issued a correction instruction to instruct automatic correction of the teaching point (St224).

[0106] If it is determined in step St224 that a correction instruction is given (YES in St224), the MR device DV corrects (changes) the postures of the (N-1) teaching points calculated based on the postures included in the teaching information, excluding the k-th teaching point (St225). The MR device DV generates (N-1) virtual welding torches based on the corrected postures of the (N-1) teaching points, and displays them in the mixed reality space (St226).

[0107] On the other hand, if the MR device DV determines in step St224 that there is no correction instruction (St224, NO), it omits correcting the posture of each of the N teaching points, generates virtual welding torches based on the N postures before correction, and displays them in the mixed reality space (St226).

[0108] <Correction method 2-1> Next, the correction method 2-1 executed in each of steps St214 and St220 will be described in detail.

[0109] The MR device DV acquires multiple teaching information (x, y, z, u, v, w) T Based on the acquired teaching information (x, y, z, u, v, w), the MR device DV generates a welding motion trajectory obtained by moving the tip of the welding torch TC of the welding robot RB in time series. T Based on this, the posture θ of the i-th welding robot RB when the posture corresponding to this teaching information is realized is ri =(θ 1i ,θ 2i ,θ 3i ,θ 4i ,θ 5i ,θ 6i ) T and the posture θ of the (i-1)th welding robot RB r(i-1) =(θ 1(i-1) ,θ 2(i-1) ,θ 3(i-1) ,θ4(i-1) ,θ 5(i-1) ,θ 6(i-1) ) T and are calculated respectively.

[0110] The MR device DV calculates the posture θ of the (i-1)th welding robot RB based on the information about the welding robot RB. r(i-1) and the posture θ of the i-th welding robot RB ri The maximum angular velocity ω of each axis of the welding robot RB moving between (i-1)i =(ω 1(i-1)i ,ω 2(i-1)i ,ω 3(i-1)i ,ω 4(i-1)i ,ω 5(i-1)i ,ω 6(i-1)i ) T The orientation Δw that minimizes the sum of squares of (i-1) The MR device DV calculates the calculated posture w (i-1) +Δw (i-1) Based on this, the posture θ of the (i-1)th welding robot RB is r(i-1) The MR device DV corrects the (i-1)th teaching information (x (i-1) ,y (i-1) ,z (i-1) ,u (i-1) ,v (i-1) ,w (i-1) ) T , teaching information (x (i-1) ,y (i-1) ,z (i-1) ,u (i-1) ,v (i-1) ,w (i-1) +Δw (i-1) ) T Correct it to:

[0111] Similarly, the MR device DV uses the acquired teaching information (x, y, z, u, v, w + Δw) T Based on this, the posture θ of the i-th welding robot RB when the posture corresponding to this teaching information is realized is ri =(θ 1i ,θ 2i ,θ 3i ,θ 4i ,θ 5i ,θ 6i ) T and the posture θ of the (i+1)th welding robot RBr(i+1) =(θ 1(i+1) ,θ 2(i+1) ,θ 3(i+1) ,θ 4(i+1) ,θ 5(i+1) ,θ 6(i+1) ) T and are calculated respectively.

[0112] The MR device DV calculates the posture θ of the ith welding robot RB based on the information about the welding robot RB. ri and the posture θ of the (i+1)th welding robot RB r(i+1) The maximum angular velocity ω of each axis of the welding robot RB moving between i(i+1) =(ω 1i(i+1) ,ω 2i(i+1) ,ω 3i(i+1) ,ω 4i(i+1) ,ω 5i(i+1) ,ω 6i(i+1) ) T The orientation Δw that minimizes the sum of squares of (i+1) The MR device DV calculates the calculated posture w (i+1) +Δw (i+1) Based on this, the posture θ of the (i+1)th welding robot RB is r(i+1) The MR device DV corrects the (i+1)th teaching information (x (i+1) ,y (i+1) ,z (i+1) ,u (i+1) ,v (i+1) ,w (i+1) ) T , teaching information (x (i+1) ,y (i+1) ,z (i+1) ,u (i+1) ,v (i+1) ,w (i+1) +Δw (i+1) ) T Correct it to:

[0113] As described above, by executing correction method 2-1, the MR device DV in the embodiment can automatically correct the posture of the teaching point taught from the viewpoint of the maximum angular velocity of the welding robot RB to a posture that is more suitable for the operation of the welding robot RB. As a result, by suppressing the magnitude of the maximum angular velocity of the welding robot RB, the MR device DV can reduce the operational load of the welding robot RB during welding, more effectively suppress positional deviation of the welding torch TC at each teaching point, and improve welding quality.

[0114] <Correction method 2-2> Next, the correction method 2-2 executed in each of steps St214 and St220 will be described in detail.

[0115] The MR device DV acquires multiple teaching information (x, y, z, u, v, w) T The MR device DV generates a welding motion trajectory of the welding torch TC provided in the welding robot RB based on the acquired teaching information (x i ,y i ,z i ,u i ,v i ,w i ) T Based on this, the posture θ of the i-th welding robot RB when the posture corresponding to this teaching information is realized is ri =(θ 1i ,θ 2i ,θ 3i ,θ 4i ,θ 5i ,θ 6i ) T and the posture θ of the (i-1)th welding robot RB r(i-1) =(θ 1(i-1) ,θ 2(i-1) ,θ 3(i-1) ,θ 4(i-1) ,θ 5(i-1) ,θ 6(i-1) ) T and are calculated respectively.

[0116] The MR device DV assigns the i-th teaching information, which is the basic posture, to the (i-1)-th teaching posture Δw (i-1)The MR device DV generates teaching information that changes only the posture w i The posture (i-1) +Δw (i-1) Δw that minimizes the takt time of the welding robot RB while correcting (i-1) Calculate.

[0117] Similarly, the MR device DV receives the acquired teaching information (x i ,y i ,z i ,u i ,v i ,w i ) T Based on this, the posture θ of the i-th welding robot RB when the posture corresponding to this teaching information is realized is ri =(θ 1i ,θ 2i ,θ 3i ,θ 4i ,θ 5i ,θ 6i ) T and the posture θ of the (i+1)th welding robot RB r(i+1) =(θ 1(i+1) ,θ 2(i+1) ,θ 3(i+1) ,θ 4(i+1) ,θ 5(i+1) ,θ 6(i+1) ) T and are calculated respectively.

[0118] The MR device DV assigns the i-th teaching information, which is the basic posture, to the (i+1)-th teaching posture w (i+1) The MR device DV determines the teaching information that minimizes the takt time among the teaching information that changes only the posture w i The posture (i+1) +Δw (i+1) Δw that minimizes the takt time of the welding robot RB while correcting (i+1) Calculate.

[0119] As described above, the MR device DV in the embodiment can minimize the total takt time of the welding robot RB operating from the first teaching point to the Nth teaching point by executing correction method 2-2. In addition, the MR device DV here minimizes the takt time by setting the welding robot RB in a posture more suitable for its operation based on information about the welding robot RB, thereby reducing the operational load of the welding robot RB during welding and improving welding efficiency (takt time).

[0120] In addition, the MR device DV corrects the posture θ of the welding robot RB by combining the correction method 2-1 and the correction method 2-2. r For example, when the teaching section taught by each of the two teaching points is a welding section in which a welding operation is taught, the MR device DV determines and corrects the posture θ at which the maximum angular velocity of each axis of the welding robot RB operating in this welding section is minimized. r is determined and corrected based on the corrected posture (w+Δw) of the welding robot RB. In addition, when the teaching section taught by each of the two teaching points is not a welding section where welding operation is taught (for example, when it is a free running section), the MR device DV determines and corrects the posture θ that minimizes the takt time of the welding robot RB operating in this teaching section. r is determined and corrected based on the corrected posture (w+Δw) of the welding robot RB.

[0121] As a result, when the MR device DV in the embodiment executes a combination of correction methods 2-1 and 2-2, it corrects the posture of the welding robot RB only in the welding section to one that minimizes the maximum angular velocity of each axis, and corrects the posture of the welding robot RB only in the non-welding section to one that minimizes the takt time, thereby improving welding quality while shortening the overall takt time.

[0122] Next, examples of welding posture correction using correction methods 2-1 and 2-2 will be described with reference to FIGS. 8 and 9, respectively. FIG. 8 is a diagram illustrating an example of a plurality of welding postures before correction. FIG. 9 is a diagram illustrating an example of a plurality of welding postures after correction. Each of FIGS. 8 and 9 illustrates an example in which six teaching points Pt1, Pt2, Pt3, Pt4, Pt5, and Pt6 are taught, and correction of the postures of these six teaching points Pt1 to Pt6 is described. Note that in the correction image SC22 shown in FIG. 9, teaching lines connecting the teaching points are omitted to make the posture of the virtual welding torch after correction easier to understand.

[0123] The MR device DV receives the teaching of each of the six teaching points Pt1 to Pt6. The MR device DV generates virtual welding torches VTC21, VTC22, VTC23, VTC24, VTC25, and VTC26 corresponding to the positions and orientations of the six teaching points Pt1 to Pt6.

[0124] The MR device DV also accepts an input operation indicating whether each teaching line (teaching section) connecting each of the six teaching points Pt1 to Pt6 is a welding line (welding section) where the welding robot RB performs welding, or a free running line (free running section) where the welding robot RB performs free running. The MR device DV generates each teaching line drawn on the captured image captured by the camera 15 with a line type (here, a solid line and a dashed line) that indicates the type of each teaching line (here, either a welding line or a free running line).

[0125] The MR device DV generates a teaching image SC21 by superimposing each of the six virtual welding torches VTC21 to VTC26 and each of the five teaching lines on the captured image captured by the camera 15. The MR device DV displays the generated teaching image SC21 on the display unit 13.

[0126] 7, if it is determined that a correction instruction has been issued, the MR device DV changes the posture of each teaching point to each of six corrected teaching points Pt1 to Pt6 calculated by correction method 2-1 or correction method 2-2. The MR device DV generates virtual welding torches VTC31, VTC32, VTC33, VTC34, VTC35, and VTC36 corresponding to each of the six corrected teaching points Pt1 to Pt6.

[0127] The MR device DV generates a corrected image SC22 by superimposing each of the six virtual welding torches VTC31 to VTC36 and each of the five teaching lines on the captured image captured by the camera 15. The MR device DV displays the generated corrected image SC22 on the display unit 13.

[0128] The corrected image SC22 shown in Fig. 9 is a corrected image generated when the third teaching point Pt3 is set as the basic orientation. In this case, the orientations of the second and fourth teaching points are automatically corrected based on the third teaching point Pt3. Furthermore, after the second teaching point Pt2 is corrected, the orientation of the first teaching point is automatically corrected based on the corrected orientation of the second teaching point Pt2.

[0129] Next, a method for correcting the posture based on fixing the sixth axis to which the welding torch TC is attached, that is, the wrist axis of the welding robot RB (hereinafter referred to as "correction method 3-1") will be described with reference to Fig. 10. Fig. 10 is a flowchart for explaining a third example of the procedure for correcting the welding posture of the MR device DV in the embodiment.

[0130] The second example of the welding posture correction procedure described in FIG. 10 is the processing executed in step St15C shown in FIG.

[0131] The MR device DV determines whether the teaching point (i.e., the i-th teaching point) whose posture is to be corrected is the welding start point (St311).

[0132] In step St311, when it is determined that the teaching point (i.e., the i-th teaching point) to be corrected is the welding start point (St311, YES), the MR device DV calculates the angle w of the wrist axis from the welding start point to the welding end point of the welding section including the welding start point. (i+1) ~w k (Step 312) where k>i.

[0133] The MR device DV is the angle w of the wrist axis at the welding start point. i Based on this, in the welding motion trajectory, the angle w of the wrist axis from the teaching point next to the welding start point to the welding end point j The angle of the wrist axis at the welding start point w i (St313) where i <j≦kである。

[0134] On the other hand, when the MR device DV determines in step St311 that the teaching point (that is, the i-th teaching point) whose posture is to be corrected is not the welding start point (St311, NO), it ends the processing shown in FIG.

[0135] <Correction method 3-1> Next, the correction method 3-1 executed in step St314 will be described in detail.

[0136] When the MR device DV determines that the teaching point to be corrected is the welding start point, it acquires the angle of the wrist axis at the welding end point of the welding section including the welding start point.The MR device DV corrects the angles of the wrist axis at all teaching positions between the welding start point and the welding end point to the angle of the wrist axis at the welding start point.

[0137] For example, the MR device DV receives the teaching information (x i ,y i ,z i ,u i ,v i ,w i ) T Based on this, the jth teaching point (x j ,y j,z j ,u j ,v j ,w j ) T , teaching information (x j ,y j ,z j ,u j ,v j ,w i ) T and the teaching information of the kth teaching point (welding end point) (x k ,y k ,z k ,u k ,v k ,w k ) T , teaching information (x k ,y k ,z k ,u k ,v k ,w i ) T Correct it to:

[0138] As a result, the MR device DV in the embodiment can fix the posture of the wrist axis of the welding robot RB while welding the same welding section by correcting the posture of the teaching point that teaches the same welding section to the same posture using correction method 3-1. By fixing the posture of the wrist axis of the welding robot RB, the MR device DV can more effectively suppress positional deviation of the welding torch TC and improve welding quality.

[0139] (Addendum) The above description of each embodiment discloses the following techniques.

[0140] (Technology 1) a model storage unit (memory 12) that stores a three-dimensional model corresponding to at least a part of a robot (welding robot RB) existing in a real environment or a welding torch TC used for welding, or a teaching member used to teach the robot (welding robot RB); a teaching data storage unit (memory 12) that stores teaching data for the robot (welding robot RB); a teaching point storage unit (memory 12) that stores teaching point data corresponding to teaching points used to display the teaching data; a display device (display unit 13) configured to be wearable by a worker and configured to display an image superimposed on an image of the real environment or the real environment itself; a positional relationship acquisition unit (processor 11) that acquires a relative positional relationship between the real environment, the teaching member, and the display device (display unit 13); an image generation unit (processor 11) that generates a display image (e.g., a teaching image or a correction image) for displaying the three-dimensional model on the display device (display unit 13) so that the three-dimensional model has a predetermined positional relationship based on the relative positional relationship and the three-dimensional model; an output unit (processor 11) that outputs the display image to the display device (display unit 13); a detection unit (depth sensor 14 or camera 15) that detects an aerial operation, which is an operation performed by the worker in the air away from the display device (display unit 13) on the three-dimensional model displayed on the display device (display unit 13), or a teaching member operation performed by the worker using the teaching member, The image generation unit (processor 11) generates and outputs the display image for displaying the three-dimensional model in a posture corresponding to a posture of the robot (welding robot RB) that satisfies the predetermined constraint condition, based on the aerial operation or the teaching member operation and a predetermined constraint condition of the robot (welding robot RB) (i.e., information on the welding robot RB). Robot teaching system (MR Device DV). As a result, the MR device DV can automatically correct the taught posture to a posture more suitable for the operation of the welding robot RB based on information about the welding robot RB, and visualize the posture of the welding torch TC at each teaching point after the correction. As a result, the MR device DV can generate teaching information that is a posture more suitable for the operation of the welding robot RB based on the constraints of the welding robot RB, thereby improving productivity in the production of workpieces Wk using the corrected teaching information and reducing the operational load of the welding robot RB during welding. The MR device DV can also support the teaching work by the worker.

[0141] (Technology 2) the predetermined constraint condition is to generate the display image for displaying the three-dimensional model in a posture corresponding to the posture of the robot that minimizes the value of a function that returns a real number based on a normalized parameter vector obtained by normalizing the posture of each of the multiple axes of the robot (welding robot RB) with respect to the operable range of each of the multiple axes; A robot teaching system (MR device DV) described in (Technology 1). This allows the MR device DV to automatically correct the posture of the taught teaching point from the perspective of the operational range of the welding robot RB to a posture that is more suitable for the operation of the welding robot RB. This allows the MR device DV to generate teaching information that improves the operational efficiency of the welding robot RB, thereby improving productivity in the production of the workpiece Wk using the corrected teaching information and reducing the operational load on the welding robot RB during welding.

[0142] (Technology 3) the image generation unit acquires a plurality of normalized parameters obtained by normalizing the postures of the plurality of axes of the robot with respect to the respective operable ranges of the plurality of axes of the robot, and calculates a first evaluation value by performing weighting processing on absolute values ​​or squared values ​​of the plurality of normalized parameters; A robot teaching system described in (Technology 2). This allows the MR device DV to automatically correct the posture of the taught teaching point from the perspective of the operational range of the welding robot RB to a posture that is more suitable for the operation of the welding robot RB. This allows the MR device DV to generate teaching information that improves the operational efficiency of the welding robot RB, thereby improving productivity in the production of the workpiece Wk using the corrected teaching information and reducing the operational load on the welding robot RB during welding.

[0143] (Technology 3) The image generation unit (processor 11) acquires normalized parameters (i.e., evaluation parameters b1 to b6) obtained by normalizing the postures of the multiple axes of the robot (welding robot RB) relative to the operable ranges of the multiple axes of the robot (welding robot RB), and calculates a first evaluation value (the sum of squares of evaluation values ​​B |B| 2 ) is minimized. (Technology 2) The robot teaching system (MR device DV) described above. This allows the MR device DV to automatically correct the taught posture to a posture closer to the median of the operable range (i.e., the range of motion) of each axis. This allows the MR device DV to generate teaching information that improves the operational efficiency of the welding robot RB, thereby improving productivity in the production of the workpiece Wk using the corrected teaching information and reducing the operational load on the welding robot RB during welding.

[0144] (Technology 4) The predetermined constraint condition is a condition that maximizes an evaluation value for evaluating the manipulability of the robot (welding robot RB), the image generation unit (processor 11) generates the display image for displaying the three-dimensional model in a posture corresponding to a posture of the robot (welding robot RB) that satisfies the predetermined constraint condition; A robot teaching system (MR device DV) described in (Technology 1). As a result, the MR device DV can automatically correct the posture of the taught teaching point to a posture that is more suitable for the operation of the welding robot RB from the viewpoint of the manipulability of the welding robot RB. As a result, the MR device DV can reduce the operating load of the welding robot RB during welding and prevent the taught posture from becoming a singular point of the welding robot RB.

[0145] (Technology 5) The predetermined constraint condition is a condition that, in a motion section of the robot (welding robot RB) based on the plurality of teaching points, the maximum angular velocity of each of a plurality of axes of the robot (welding robot RB) moving between two consecutive teaching points is minimized, the image generation unit (processor 11) generates the display image for displaying the three-dimensional model in a posture corresponding to a posture of the robot (welding robot RB) that satisfies the predetermined constraint condition; A robot teaching system (MR device DV) described in (Technology 1). As a result, the MR device DV can automatically correct the posture of the taught teaching point to a posture that is more suitable for the operation of the welding robot RB from the viewpoint of the maximum angular velocity of the welding robot RB. As a result, the MR device DV can reduce the operating load of the welding robot RB during welding by suppressing the magnitude of the maximum angular velocity of the welding robot RB, and can more effectively suppress positional deviation of the welding torch TC at each teaching point, thereby improving welding quality.

[0146] (Technology 6) the image generation unit (processor 11) sets the teaching point selected by the worker as a basic teaching point, sets the posture at the basic teaching point as a basic posture, and generates the display image for displaying the three-dimensional model at the two consecutive teaching points based on the basic posture in a posture corresponding to the posture of the robot (welding robot RB) that satisfies the predetermined constraint condition; A robot teaching system (MR device DV) described in (Technology 5). As a result, by determining a teaching point that serves as the basic posture, the MR device DV can automatically correct the posture of the teaching point based on this basic posture to a posture that is more suitable for the operation of the welding robot RB. As a result, the MR device DV can correct the posture to one that can more effectively suppress the magnitude of the maximum angular velocity of the welding robot RB between successive teaching points on the operation section, thereby reducing the operating load of the welding robot RB during welding and more effectively suppressing positional deviation of the welding torch TC at each teaching point, thereby improving welding quality.

[0147] (Technology 7) The predetermined constraint condition is a condition that a movement time of the robot (welding robot RB) moving between two consecutive teaching points is minimized in an operation section of the robot (welding robot RB) based on the plurality of teaching points, the image generation unit (processor 11) generates the display image for displaying the three-dimensional model in a posture corresponding to a posture of the robot (welding robot RB) that satisfies the predetermined constraint condition; A robot teaching system (MR device DV) described in (Technology 1). As a result, the MR device DV can shorten the overall takt time by correcting the posture of the welding robot RB to one that minimizes the takt time in each operation section.

[0148] (Technology 8) The predetermined constraint condition is a condition that the maximum angular velocity of each of a plurality of axes of the robot (welding robot RB) moving between two consecutive teaching points in a welding section among operation sections of the robot (welding robot RB) based on the plurality of teaching points is minimized, and that the movement time of the robot (welding robot RB) moving between two consecutive teaching points in a non-welding section is minimized, the image generation unit (processor 11) generates the display image for displaying the three-dimensional model in a posture corresponding to a posture of the robot (welding robot RB) that satisfies the predetermined constraint condition; A robot teaching system (MR device DV) described in (Technology 1). As a result, the MR device DV corrects the posture of the welding robot RB in the welding section to minimize the maximum angular velocity of each axis, and then corrects the posture of the welding robot RB only in the non-welding section to minimize the takt time, thereby improving the welding quality of the welding performed in the welding section while more effectively shortening the takt time of the entire operating section in which the welding robot RB operates (i.e., non-welding section + welding section).

[0149] (Technology 9) The predetermined constraint condition is a condition for changing a wrist posture of a teaching point included in the same welding section to a wrist posture of a teaching point at a welding start point of the welding section, the image generation unit (processor 11) generates the display image for displaying the three-dimensional model in a posture corresponding to a posture of the robot (welding robot RB) that satisfies the predetermined constraint condition; A robot teaching system (MR device DV) described in (Technology 1). As a result, the MR device DV can fix the posture of the wrist axis of the welding robot RB while welding the same welding section by correcting the posture of the teaching point that teaches the same welding section to the same posture. By fixing the posture of the wrist axis of the welding robot RB, the MR device DV can more effectively suppress positional deviation of the welding torch TC and improve welding quality.

[0150] (Technology 10) A robot teaching method executed by at least one computer (processor 11), comprising: storing a three-dimensional model corresponding to at least a part of a robot (welding robot RB) existing in a real environment or a welding torch TC used for welding, or a teaching member used for teaching the robot (welding robot RB), teaching data of the robot (welding robot RB), and teaching point data corresponding to teaching points used for displaying the teaching data; acquiring a relative positional relationship between the real environment, the teaching member, and a display device (display unit 13) configured to be wearable by a worker and configured to display an image of the real environment or the real environment itself by superimposing the image; generating a display image (e.g., a teaching image or a correction image) for displaying the three-dimensional model on the display device (display unit 13) based on the relative positional relationship and the three-dimensional model so that the three-dimensional model has a predetermined positional relationship; outputting the display image to the display device (display unit 13); Detecting an aerial operation, which is an operation performed by the worker in the air away from the display device (display unit 13) on the three-dimensional model displayed on the display device (display unit 13), or a teaching member operation performed by the worker using the teaching member; generating and outputting the display image for displaying the three-dimensional model in a posture corresponding to a posture of the robot (welding robot RB) that satisfies the predetermined constraint condition based on the aerial operation or the teaching member operation and a predetermined constraint condition of the robot (welding robot RB) (i.e., information on the welding robot RB); Robot teaching method. As a result, the MR device DV can automatically correct the taught posture to a posture more suitable for the operation of the welding robot RB based on information about the welding robot RB, and visualize the posture of the welding torch TC at each teaching point after the correction. As a result, the MR device DV can generate teaching information that is a posture more suitable for the operation of the welding robot RB based on the constraints of the welding robot RB, thereby improving productivity in the production of workpieces Wk using the corrected teaching information and reducing the operational load of the welding robot RB during welding. The MR device DV can also support the teaching work by the worker.

[0151] Although various embodiments have been described above with reference to the accompanying drawings, the present disclosure is not limited to such examples. It is clear that those skilled in the art can conceive of various modifications, alterations, substitutions, additions, deletions, and equivalents within the scope of the claims, and it is understood that these also fall within the technical scope of the present disclosure. Furthermore, the components of the various embodiments described above may be combined in any manner without departing from the spirit of the invention. [Industrial Applicability]

[0152] The present disclosure is useful as a robot teaching system and a robot teaching method for correcting the teaching posture of a taught teaching point to a posture more suitable for a welding robot. [Explanation of symbols]

[0153] 10,20 Communications Department 11,21 processor 12,22 memory 13 Display section 14 Depth Sensor 15 Camera 100 Welding Teaching System 221 Instruction Information Recording Unit 222 Work information recording unit DV MR device P1 Processing Unit Pt1, Pt2, Pt3, Pt4, Pt5, Pt6 teaching points RB welding robot SC11, SC21 teaching images SC12, SC22 corrected image TC welding torch TL Teaching Tool VRB Virtual Welding Robot VTC Virtual Welding Torch Wk Work WW Welding Wire

Claims

1. a model storage unit that stores a three-dimensional model corresponding to at least a part of a robot or a welding torch used in welding that exists in a real environment, or a teaching member used to teach the robot; a teaching data storage unit that stores teaching data of the robot; a teaching point storage unit that stores teaching point data corresponding to teaching points used to display the teaching data; a display device configured to be wearable by a worker and configured to display an image superimposed on an image of the real environment or the real environment itself; a positional relationship acquisition unit that acquires a relative positional relationship between the real environment, the teaching member, and the display device; an image generation unit that generates a display image for displaying the three-dimensional model in a predetermined positional relationship with respect to the display device, based on the relative positional relationship and the three-dimensional model; an output unit that outputs the display image to the display device; a detection unit that detects an aerial operation, which is an operation performed by the worker in the air away from the display device on the three-dimensional model displayed on the display device, or a teaching member operation performed by the worker using the teaching member, the image generation unit generates and outputs the display image for displaying the three-dimensional model in a posture corresponding to a posture of the robot that satisfies the predetermined constraint condition, based on the aerial operation or the teaching member operation and a predetermined constraint condition of the robot. Robot teaching system.

2. the predetermined constraint condition is to generate the display image for displaying the three-dimensional model in a posture corresponding to the posture of the robot that minimizes the value of a function that returns a real number, based on a normalized parameter vector obtained by normalizing the posture of each of the multiple axes of the robot with respect to the operable range of each of the multiple axes of the robot; The robot teaching system according to claim 1 .

3. the image generation unit acquires a plurality of normalized parameters obtained by normalizing the postures of the plurality of axes of the robot with respect to the respective operable ranges of the plurality of axes of the robot, and calculates a first evaluation value obtained by performing a weighting process on absolute values ​​or squared values ​​of the plurality of normalized parameters; The robot teaching system according to claim 2 .

4. The predetermined constraint condition is a condition that maximizes an evaluation value for evaluating the manipulability of the robot, the image generation unit generates the display image for displaying the three-dimensional model in a posture corresponding to a posture of the robot that satisfies the predetermined constraint condition. The robot teaching system according to claim 1 .

5. the predetermined constraint condition is a condition that a maximum angular velocity of each of a plurality of axes of the robot moving between two consecutive teaching points is minimized in a motion section of the robot based on the plurality of teaching points, the image generation unit generates the display image for displaying the three-dimensional model in a posture corresponding to a posture of the robot that satisfies the predetermined constraint condition. The robot teaching system according to claim 1 .

6. the image generation unit sets a teaching point selected by the worker as a basic teaching point, sets a posture at the basic teaching point as a basic posture, and generates the display image for displaying the three-dimensional model at the two consecutive teaching points based on the basic posture in a posture corresponding to a posture of the robot that satisfies the predetermined constraint condition. The robot teaching system according to claim 5 .

7. the predetermined constraint condition is a condition that a movement time of the robot moving between two consecutive teaching points is minimized in a movement section of the robot based on the plurality of teaching points, the image generation unit generates the display image for displaying the three-dimensional model in a posture corresponding to a posture of the robot that satisfies the predetermined constraint condition. The robot teaching system according to claim 1 .

8. The predetermined constraint condition is a condition that a maximum angular velocity of each of a plurality of axes of the robot moving between two consecutive teaching points in a welding section among operation sections of the robot based on the plurality of teaching points is minimized, and a movement time of the robot moving between two consecutive teaching points in a non-welding section is minimized, the image generation unit generates the display image for displaying the three-dimensional model in a posture corresponding to a posture of the robot that satisfies the predetermined constraint condition. The robot teaching system according to claim 1 .

9. The predetermined constraint condition is a condition for changing a wrist posture of a teaching point included in the same welding section to a wrist posture of a teaching point at a welding start point of the welding section, the image generation unit generates the display image for displaying the three-dimensional model in a posture corresponding to a posture of the robot that satisfies the predetermined constraint condition. The robot teaching system according to claim 1 .

10. 1. A method for teaching a robot executed by at least one computer, comprising: storing a three-dimensional model corresponding to at least a part of a robot or a welding torch used for welding that exists in a real environment, or a teaching member used to teach the robot, teaching data of the robot, and teaching point data corresponding to teaching points used to display the teaching data; acquiring a relative positional relationship between the real environment, the teaching member, and a display device configured to be wearable by a worker and displaying an image of the real environment or the real environment itself by superimposing the image; generating a display image for displaying the three-dimensional model in a predetermined positional relationship with respect to the display device based on the relative positional relationship and the three-dimensional model; outputting the display image to the display device; detecting an aerial operation, which is an operation performed by the worker in the air away from the display device on the three-dimensional model displayed on the display device, or a teaching member operation performed by the worker using the teaching member; generating and outputting the display image for displaying the three-dimensional model in a posture corresponding to a posture of the robot that satisfies the predetermined constraint conditions based on the aerial operation or the teaching member operation and predetermined constraint conditions of the robot; Robot teaching method.

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