Robot system, robot control device, control method, and computer-readable recording medium

Abstract

This invention provides a robot system, robot control device, control method, and program that enable simpler robot movement teaching. The robot system includes: a feature point teaching unit that stores the positions of feature points taught using guided teaching in a storage unit; an input receiving unit that receives input of the angle values ​​of a tool relative to a workpiece (W); a posture determination unit that determines the posture of the tool based on the tool's angle values; and a program generation unit that generates a robot program for the robot based on the positions and postures of the feature points.

Description

Technical Field

[0001] This invention relates to robot systems, robot control devices, control methods, and computer programs. Background Technology

[0002] Traditionally, welding robots achieve stable welding through their movements, freeing operators from the spatter and fumes generated during welding. The movements of such welding robots are taught using various methods (for example, see Patent Document 1). The industrial robot described in Patent Document 1 uses lead-through teaching (also known as direct teaching) to teach the robot's movements.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 60-233707 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] Such welding robots require consideration of the relative positions and postures of the welding tools and workpieces during welding, and necessitate teaching the robot's movements. Therefore, operators need a high level of skill to teach the welding robot's movements. Consequently, a robot system that allows for easier teaching of robot movements is desired.

[0008] Methods for solving problems

[0009] The robot system disclosed herein is a robot system that uses motion patterns with feature points to weld workpieces, comprising: a feature point teaching unit that stores the positions of the feature points taught using guided teaching in a storage unit; an input receiving unit that receives input of the angle value of the tool relative to the workpiece; a posture determination unit that determines the posture of the tool based on the angle value of the tool; and a program generation unit that generates a robot program for the robot based on the position of the feature points and the posture.

[0010] The robot control device disclosed herein is a robot control device for welding workpieces using motion patterns with feature points, comprising: a feature point teaching unit that stores the positions of the feature points taught using guided teaching in a storage unit; an input receiving unit that receives input of angle values ​​of a tool relative to the workpiece; a posture determination unit that determines the posture of the tool based on the angle values ​​of the tool; and a program generation unit that generates a robot program for the robot based on the positions of the feature points and the posture.

[0011] The control method disclosed herein is a robot control method for welding a workpiece using a motion pattern with feature points. The robot control method includes the following steps: storing the position of the feature points taught using guided teaching; accepting input of the angle value of the tool relative to the workpiece; determining the posture of the tool based on the angle value of the tool; and generating a robot program for the robot based on the position of the feature points and the posture.

[0012] The computer program disclosed herein is used to cause a computer to perform the following steps: storing the positions of feature points constituting a motion pattern taught using guided teaching; accepting input of an angle value of a tool relative to a workpiece; determining the posture of the tool based on the angle value of the tool; and generating a robot program for a robot based on the positions of the feature points and the posture.

[0013] Invention Effects

[0014] According to the present invention, it is possible to teach the robot's movements more easily. Attached Figure Description

[0015] Figure 1 This is a diagram showing an overview of the robot system according to this embodiment.

[0016] Figure 2 This is a diagram illustrating the functional structure of the robot system in this embodiment.

[0017] Figure 3 This is a diagram illustrating a specific example of guided instruction.

[0018] Figure 4 This is a diagram illustrating a specific example of how the angle of a tool is determined based on an angle value.

[0019] Figure 5 This is a diagram illustrating a specific example of how the position and / or angle of a tool can be shifted.

[0020] Figure 6A This is a diagram showing an example of a display on the display section of the teach pendant.

[0021] Figure 6B This is a diagram showing an example of a display on the display section of the teach pendant.

[0022] Figure 6C This is a diagram showing an example of a display on the display section of the teach pendant.

[0023] Figure 6D This is a diagram showing an example of a display on the display section of the teach pendant.

[0024] Figure 7 This is a flowchart illustrating the processing flow of the robot system in this embodiment. Detailed Implementation

[0025] Hereinafter, an example of an embodiment of the present invention will be described.

[0026] Figure 1 This is a diagram showing an outline of the robot system 1 according to this embodiment. The robot system 1 is a system for performing arc welding using a robot 10. The robot system 1 includes a robot 10, a robot control device 20, and a teach pendant 30.

[0027] Robot 10 operates under the control of robot control device 20. Robot 10 is a welding robot, equipped with tool 11 and arm 12.

[0028] The robot control device 20 is connected to the robot 10 and the teaching pendant 30, and controls the actions of the robot 10. For example, the robot control device 20 controls the actions of the robot 10 according to the operation of the teaching pendant 30.

[0029] The teaching control panel 30 is connected to the robot control device 20 and is used for the operator to operate the robot 10.

[0030] Figure 2 This is a diagram illustrating the functional structure of the robot system 1 in this embodiment. (See diagram for example.) Figure 2 As shown, the robot control device 20 includes a control unit 21 and a storage unit 22. The control unit 21 is a processor such as a CPU (Central Processing Unit). The control unit 21 performs various processes by executing programs stored in the storage unit 22.

[0031] In addition, the control unit 21 includes a feature point teaching unit 211, an input receiving unit 212, a posture determination unit 213, a program generation unit 214, and a display control unit 215.

[0032] Storage unit 22 is a storage device such as ROM (Read-Only Memory), RAM (Random Access Memory), hard disk drive or SSD (Solid State Drive) that stores the OS (Operating System) and applications, as well as other various information.

[0033] The teaching control panel 30 includes a control unit 31, an operation unit 32, and a display unit 33.

[0034] The control unit 31 performs various processes by controlling the operation of the teach pendant 30. The operation unit 32 consists of buttons, keys, switches, etc., and receives various operations from the operator. The display unit 33 consists of an LCD screen, etc., and displays various information.

[0035] Alternatively, the operation unit 32 and the display unit 33 can also be composed of an integrated touch panel or the like. Furthermore, the teach pendant 30 can also be composed of a tablet terminal.

[0036] Next, the teaching of the actions of the robot 10 in the robot system 1 of this embodiment will be explained.

[0037] When the operator uses guided teaching to teach the position of the feature points that constitute the action pattern, the feature point teaching unit 211 stores the position of the feature points taught using guided teaching in the storage unit 22. Here, "guided teaching" specifically refers to the method of teaching by having the operator grasp the arm 12 of the robot 10 and move the robot 10.

[0038] In addition, the motion pattern of robot 10 includes multiple feature points, consisting of straight lines, arcs, etc. For example, the motion pattern can also include the welding start point and welding end point as feature points.

[0039] Additionally, the action pattern may include at least one of a start offset point that is offset from the welding start point by position and / or angle and an end offset point that is offset from the welding end point by position and / or angle.

[0040] In addition, the action mode is represented by a command block. Furthermore, the action mode includes at least one of the following as attributes of the command block: the welding start point and the position and angle offset from the welding start point, the angle value of tool 11, the welding end point and the position and angle offset from the welding end point, and the welding conditions.

[0041] Here, welding conditions include the welding current, voltage, waveform (e.g., pulse waveform, sine wave, etc.), and welding type (e.g., MIG welding, MAG welding, etc.). Additionally, a command block is the unit for executing the robot program, representing one line of instructions in the robot program.

[0042] The receiving unit 212 receives the angle value of the receiving tool 11 relative to the workpiece. Specifically, it receives the target angle and the forward / backward angle of the receiving tool 11 relative to the workpiece. Additionally, it receives the offset distance of the receiving tool 11. These inputs are made, for example, by the operator using the teach pendant 30.

[0043] Here, when the arc is ahead of the tool (welding torch) relative to the tool's direction of travel, it is called the torch advance method, and the angle between the tool and the perpendicular line relative to the workpiece is called the torch advance angle. On the other hand, when the arc is behind the tool's direction of travel, it is called the torch retreat method, and the angle between the tool and the perpendicular line relative to the workpiece is called the torch retreat angle.

[0044] The posture determination unit 213 determines the posture of the tool 11 based on the angle value of the tool 11. Specifically, the posture determination unit 213 uses the line connecting the feature points as a reference line. Then, based on the angle value of the tool 11, the posture determination unit 213 determines the angle of the tool 11 relative to the reference line in a predetermined reference plane. Then, the posture determination unit 213 determines the angle of the tool 11 relative to the reference line when the robot 10 moves.

[0045] Here, the predetermined reference plane is any one of the following: a user-defined plane arbitrarily defined by the user, the horizontal plane of the robot 10, or the plane defining the posture of the tool 11. Alternatively, the horizontal plane of the robot 10 can also be a plane orthogonal to the vertical direction. Similarly, the plane defining the posture of the tool 11 can be a plane defined as the initial posture of the tool 11.

[0046] Alternatively, the predetermined reference plane can also be defined by the welding start point, the welding end point, and points other than the welding start point and the welding end point.

[0047] The program generation unit 214 generates a robot program for the robot based on the position of the feature points and the pose of the tool 11. That is, the robot program generated by the program generation unit 214 includes motion patterns.

[0048] Thus, robot system 1 can weld workpieces using a robot program that includes motion patterns. The program generation unit 214 stores the generated robot program in the storage unit 22.

[0049] Figure 3 This is a diagram illustrating a specific example of guided instruction. For example... Figure 3 As shown, the operator grasps the arm 12 of robot 10 and moves the arm 12 of robot 10 towards position P1, which constitutes the feature point of the motion pattern. Then, the operator moves the arm 12 of robot 10 towards position P2, which constitutes the feature point of the motion pattern.

[0050] Furthermore, the feature point teaching unit 211 stores the positions P1 and P2 of the feature points taught using guided teaching performed by the operator. For example, the position P1 of the taught feature point is the welding start point, and the position P2 of the taught feature point is the welding end point.

[0051] Figure 4 This is a diagram illustrating a specific example of how the angle of a tool is determined based on an angle value. For example... Figure 4As shown, the posture determination unit 213 determines the posture based on the angle value. Figure 3 Using the position of tool 11 at location P1 as a reference, determine the angle θ1 by which tool 11 is tilted in the vertical direction.

[0052] Furthermore, the posture determination unit 213, based on the angle value, ... Figure 3 Using the position of tool 11 at location P2 as a reference, determine the angle θ2 by which tool 11 is tilted toward the horizontal plane of workpiece W (the direction of the horizontal plane orthogonal to the vertical direction).

[0053] Figure 5 This is a diagram illustrating a specific example of positional and / or angular offset of tool 11. The target angle θ3 of tool 11 is an angle based on the horizontal plane of workpiece W, and the target angle θ4 of tool 11 is an angle based on the vertical plane of workpiece W.

[0054] The target angle θ3 or θ4 of tool 11 is input by the operator using the teach pendant 30 and processed by the input receiving unit 212. Then, the posture determination unit 213 determines the posture of tool 11 based on the value processed by the input receiving unit 212.

[0055] like Figure 5 As shown, tool 11 is offset from the position of the taught feature point after welding is completed. Additionally, tool 11 can also be offset from the position and angle of the taught feature point after welding is completed.

[0056] The offset position and / or angle are input by the operator using the teach pendant 30 and processed by the input receiving unit 212. Then, the posture determination unit 213, based on the position and / or angle processed by the input receiving unit 212, offsets the position and / or angle of the position offset tool 11 from the position of the taught feature point.

[0057] Figures 6A to 6D This diagram shows an example of a display shown on the display unit 33 of the teach pendant 30. For example... Figure 6A As shown, the display control unit 215 uses guided teaching, displaying a first display mode 331 for teaching the operation mode on the display unit 33. The operator selects this first display mode 331 through the operation unit 32, thereby starting the teaching of the operation mode.

[0058] Next, as Figure 6B As shown, the display control unit 215 displays a second display mode 332 on the display unit 33 for teaching the welding start point and welding end point. The operator selects the "start" icon of this second display mode 332 via the operation unit 32. Then, the operator uses, for example, guided teaching to move the arm 12 of the robot 10 to teach the welding start point. Similarly, the operator can also use guided teaching to move the arm 12 of the robot 10 to teach the welding end point.

[0059] Next, as Figure 6C As shown, the display control unit 215 displays a third display mode 333 for storing the welding start point of the illustrated teaching on the display unit 33. The operator selects this third display mode 333 via the operation unit 32. Consequently, the feature point teaching unit 211 stores the welding start point of the illustrated teaching in the storage unit 22. Similarly, the display control unit 215 displays a third display mode 333 for storing the welding end point of the illustrated teaching on the display unit 33. The operator selects this third display mode 333 via the operation unit 32. The feature point teaching unit 211 stores the welding end point of the illustrated teaching in the storage unit 22.

[0060] Next, as Figure 6D As shown, the display control unit 215 displays a fourth display mode 334 for accepting input of the forward / backward angle of the tool 11 relative to the workpiece. The operator inputs the angle value of the tool 11 through the operation unit 32.

[0061] The input receiving unit 212 receives the input of the target angle and the forward / backward angle of the tool 11 relative to the workpiece. In addition, the posture determination unit 213 determines the posture of the tool 11 based on the input target angle and forward / backward angle.

[0062] Figure 7 This is a flowchart illustrating the processing flow of the robot system 1 in this embodiment. In step S1, if the operator uses guided teaching to teach the positions of feature points constituting the action pattern, the feature point teaching unit 211 stores the positions of the feature points taught using guided teaching in the storage unit 22.

[0063] In step S2, the angle value of the receiving tool 11 of the receiving unit 212 relative to the workpiece is input.

[0064] In step S3, the posture determination unit 213 determines the posture of the tool 11 based on the angle value of the tool 11.

[0065] In step S4, the program generation unit 214 generates a robot program for the robot 10 based on the position of the feature points and the pose of the tool 11.

[0066] As described above, according to this embodiment, the robot system 1 includes: a feature point teaching unit 211, which stores the positions of feature points taught using guided teaching in a storage unit 22; an input receiving unit 212, which receives input of the angle value of the tool 11 relative to the workpiece W; a posture determination unit 213, which determines the posture of the tool 11 based on the angle value of the tool 11; and a program generation unit 214, which generates a robot program for the robot 10 based on the position and posture of the feature points.

[0067] In this way, robot system 1 uses guided teaching to teach feature points, allowing the operator to intuitively teach the position. Furthermore, robot system 1 determines the posture based on angle values, thus enabling the tool 11 to be set at an angle suitable for welding.

[0068] Furthermore, robot system 1 sets the target angle and forward / backward angle as the angle values ​​of tool 11, and only teaches the positions of the two feature points, thereby enabling the teaching of robot 10 for welding. Therefore, robot system 1 can more easily teach the robot's movements.

[0069] Furthermore, the motion pattern includes multiple feature points that form straight lines, arcs, etc. Therefore, even if the motion pattern includes curves such as straight lines and arcs, the robot system 1 can still specify the direction of travel of the tool 11. Thus, the robot system 1 can more easily teach the robot's movements.

[0070] Additionally, the action mode includes at least one of a start offset point that offsets the position and / or angle of tool 11 from the welding start point, and an end offset point that offsets the position and / or angle of tool 11 from the welding end point. Thus, the robot system 1 can appropriately set the offset position and / or angle of tool 11.

[0071] Furthermore, the action mode is represented by a command block, which includes at least one of the following attributes of the command block: welding start point and its offset position and angle from the welding start point, angle value of tool 11, welding end point and its offset position and angle from the welding end point, and welding conditions. Thus, robot system 1 can more easily generate robot programs by calling the command block in the program.

[0072] Furthermore, the posture determination unit 213 uses the line connecting the feature points as a reference line. Then, based on the angle value, the posture determination unit 213 determines the angle of the tool 11 relative to the reference line in the predetermined reference plane, and thus determines the angle of the tool 11 relative to the reference line when the robot 10 moves. As a result, the robot system 1 can appropriately determine the angle of the tool 11.

[0073] Alternatively, the predetermined reference plane can be any one of the following: a user-defined plane, the horizontal plane of the robot 10, or the plane defining the posture of the tool 11. Thus, the robot system 1 can use an appropriate reference plane to determine the angle of the tool 11.

[0074] Furthermore, the predetermined reference plane can also be defined by the welding start point, the welding end point, and one or more points other than the welding start point and the welding end point. Therefore, robot system 1 can define the reference plane without pre-defining the tool coordinate system of tool 11. Additionally, by using the welding start point and welding end point, robot system 1 can define the reference plane with fewer teaching points. Only one additional point is needed, making teaching easy. With an increased number of points, a more appropriate plane can be defined through averaging or similar methods.

[0075] Furthermore, while the embodiments of the present invention have been mainly described in relation to arc welding, they can also be applied to other welding methods such as laser welding and spot welding, as well as applications such as sealing, deburring, cleaning, and painting.

[0076] The embodiments of the present invention have been described above, but the robot system can be implemented using hardware, software, or a combination thereof. Furthermore, the control method achieved through the cooperation of the robot systems themselves can also be implemented using hardware, software, or a combination thereof. Here, software implementation means implementing it by loading a program into a computer and executing it.

[0077] Programs can be stored and provided to a computer using various types of non-transitory computer-readable media. Non-transitory computer-readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (e.g., hard disk drives), optical-magnetic recording media (e.g., optical discs), CD-ROMs (Read Only Memory), CD-Rs, CD-R / Ws, semiconductor memories (e.g., mask ROMs, PROMs (Programmable ROMs), EPROMs (Erasable PROMs), flash memory ROMs, and RAMs (random access memory)).

[0078] Furthermore, the above-described embodiments are preferred embodiments of the present invention, but the scope of the present invention is not limited to the above-described embodiments. It can be implemented in various ways without departing from the spirit of the present invention.

[0079] Explanation of reference numerals in the attached figures

[0080] 1. Robot system

[0081] 10. Robots

[0082] 20. Robot control device

[0083] 30 Teaching operation panel,

[0084] 211 Feature Point Demonstration Department

[0085] 212 Input Acceptance Department

[0086] 213 Posture Determination Department

[0087] 214 Program Generation Department.

Claims

1. A robot system that uses motion patterns with feature points to weld workpieces, characterized in that, This robot system has the following features: The feature point teaching unit stores the position of the feature point taught by the guided teaching in the storage unit when the operator uses guided teaching to teach the position of the feature point constituting the action pattern. The guided teaching is performed by the operator grasping the arm of the robot constituting the robot system and moving the robot. Input reception unit, including the angle value of its reception tool relative to the workpiece; An attitude determination unit determines the attitude of the tool based on the angle value of the tool; The program generation unit generates a robot program for the robot based on the position of the feature points and the pose. as well as The display control unit uses the guided teaching method to display on the display unit of the teaching operation panel a user interface for teaching the operation mode in a first display mode, a user interface for teaching the welding start point and the welding end point in a second display mode, a user interface for storing the taught welding start point and the welding end point in a third display mode, and a user interface for accepting input of the tool's advance angle / retreat angle relative to the workpiece.

2. The robot system according to claim 1, characterized in that, The action pattern includes multiple of the aforementioned feature points.

3. The robot system according to claim 1 or 2, characterized in that, The action mode includes at least one of a start offset point that offsets the position and / or angle of the tool from the welding start point and an end offset point that offsets the position and / or angle of the tool from the welding end point.

4. The robot system according to claim 1 or 2, characterized in that, The action mode is represented by a command block, which includes at least one of the following as attributes of the command block: welding start point and position and angle offset from the welding start point, angle value of the tool, welding end point and position and angle offset from the welding end point, and welding conditions.

5. The robot system according to claim 1 or 2, characterized in that, The posture determination unit uses the line connecting the feature points as a reference line, and determines the angle of the tool relative to the reference line in the predetermined reference plane based on the angle value, thereby determining the angle of the tool relative to the reference line when the robot moves.

6. The robot system according to claim 5, characterized in that, The predetermined reference plane is any one of the following: a user-defined plane arbitrarily defined by the user, the robot's horizontal plane, and the tool's posture definition plane.

7. The robot system according to claim 5, characterized in that, The predetermined reference plane is defined by the welding start point, the welding end point, and one or more points other than the welding start point and the welding end point.

8. A robot control device for welding workpieces using motion patterns with feature points, characterized in that, The robot control device has the following features: The feature point teaching unit stores the position of the feature point taught by the guided teaching in the storage unit when the operator uses guided teaching to teach the position of the feature point constituting the action pattern. The guided teaching is performed by the operator grasping the arm of the robot constituting the robot system and moving the robot. Input reception unit, including the angle value of its reception tool relative to the workpiece; An attitude determination unit determines the attitude of the tool based on the angle value of the tool; The program generation unit generates a robot program for the robot based on the position of the feature points and the pose. as well as The display control unit uses the guided teaching method to display on the display unit of the teaching operation panel a user interface for teaching the operation mode in a first display mode, a user interface for teaching the welding start point and the welding end point in a second display mode, a user interface for storing the taught welding start point and the welding end point in a third display mode, and a user interface for accepting input of the tool's advance angle / retreat angle relative to the workpiece.

9. A robot control method that uses motion patterns with feature points to weld workpieces, characterized in that, The robot control method includes the following steps: When an operator uses guided teaching to teach the position of the feature points constituting the action pattern, the steps of using the guided teaching to teach the position of the feature points taught by the guided teaching are stored, wherein the guided teaching is performed by the operator grasping the arm of the robot constituting the robot system and moving the robot. The step of inputting the angle value of the receiving tool relative to the workpiece; The step of determining the posture of the tool based on the angle value of the tool; The steps for generating a robot program for the robot based on the location of the feature points and the pose; as well as The steps of using the guided teaching method to display on the display section of the teaching operation panel a user interface for teaching the operation mode in a first display mode, a user interface for teaching the welding start point and the welding end point, a user interface for storing the taught welding start point and the welding end point, and a user interface for accepting the input of the tool's forward angle / backward angle relative to the workpiece.

10. A computer-readable recording medium containing a computer program, characterized in that, This computer program causes the computer to perform the following steps: When an operator uses guided teaching to teach the positions of feature points constituting a motion pattern, the steps of using the guided teaching to teach the positions of feature points constituting a motion pattern taught by the guided teaching, wherein the guided teaching is performed by the operator grasping the arm of the robot constituting the robot system and moving the robot. The steps for inputting the angle value of the receiving tool relative to the workpiece; The step of determining the posture of the tool based on the angle value of the tool; The steps for generating a robot program for the robot based on the location of the feature points and the pose; as well as The steps of using the guided teaching method to display on the display section of the teaching operation panel a user interface for teaching the operation mode in a first display mode, a user interface for teaching the welding start point and the welding end point, a user interface for storing the taught welding start point and the welding end point, and a user interface for accepting the input of the tool's forward angle / backward angle relative to the workpiece.

Images