Welding device

Abstract

To provide a welding device that can restrain movement of a heat source to the outside of an intended area.SOLUTION: A welding device 100 includes: a heat source 11 for welding; a multi-axis robot 12 holding and moving the heat source 11; sensors S1, S2, S3 to detect that the heat source 11 has reached a limit of a prescribed permitted area established for a workpiece W; an input device 30 to receive an input for operating the multi-axis robot 12 from an operator H; and a control device 20 for the multi-axis robot 12, the control device 20 being configured to impose a limitation to the movement of the heat source 11 in a direction exceeding the limit when it is detected that the heat source 11 has reached the limit by the sensors S1, S2, S3 while during the operation of the multi-axis robot 12 that is based on input from the operator H to the input device 30.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a welding apparatus.

Background Art

[0002] In remote welding, instead of a human hand, a robot moves a heat source such as a welding torch. In remote welding, a welder operates the robot. In remote welding, it is often difficult for the welder to accurately grasp the position of the heat source with respect to the workpiece. For example, Patent Document 1 discloses a welding apparatus including a camera. In Patent Document 1, a plurality of images taken from different directions by the camera are processed, and the position of the welding torch with respect to the workpiece is displayed on a display. An operator can perform remote operation while checking the images displayed on the display.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In remote welding, a welder is often required to move the heat source along a complex path. For example, when the welder accidentally moves the welding apparatus, or when an unintended operation is input to the input interface, problems such as the heat source colliding with the workpiece or the quality of the welding deteriorating may occur.

[0005] An object of the present disclosure is to provide a welding apparatus capable of suppressing the movement of the heat source outside an intended area.

Means for Solving the Problems

[0006] A welding apparatus according to one aspect of the present disclosure includes a heat source for welding, a multi-axis robot that holds and moves the heat source, a sensor that detects when the heat source has reached the limit of a predetermined allowable area set for a workpiece, an input device that receives input from an operator for operating the multi-axis robot, and a control device for the multi-axis robot that is configured to, when the sensor detects that the heat source has reached the limit during operation of the multi-axis robot based on input from the operator to the input device, impose a restriction on movement of the heat source in a direction exceeding the limit.

[0007] The controller may set the permission region based on data from the sensor.

[0008] The controller may send a command to the multi-axis robot to reduce the rate of movement of the heat source in a direction that exceeds the limit as a restriction.

[0009] The controller may send a command to the multi-axis robot to provide a resistance to movement of the heat source in a direction beyond the limit as a constraint.

[0010] The controller may send a command to the multi-axis robot to multiply the speed of movement of the heat source in a direction beyond the limit by a factor of two as a restriction.

[0011] The control device may send a command to the multi-axis robot to prohibit movement of the heat source in a direction that exceeds the limit as a restriction.

[0012] The input device may receive an input for lifting the restriction from the worker, and the control device may lift the restriction when the input device receives the input for lifting the restriction. Effect of the Invention

[0013] According to the present disclosure, the movement of the heat source outside the intended area can be suppressed. [Brief description of the drawings]

[0014]

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Embodiments for Carrying Out the Invention

[0015] Embodiments of the present disclosure will be described in detail with reference to the accompanying drawings below. Specific dimensions, materials, numerical values, etc. shown in such embodiments are merely examples for ease of understanding and do not limit the present disclosure unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals to omit redundant description, and elements not directly related to the present disclosure are not shown.

[0016] FIG. 1 is a schematic diagram showing a welding apparatus 100 according to an embodiment. For example, the welding apparatus 100 includes a remote welding robot 10, a control device 20, an input device 30, and a display 40. The welding apparatus 100 may further include other components. Also, the welding apparatus 100 may not include at least one of the above components.

[0017] The remote welding robot 10 includes a torch (heat source) 11, a manipulator (multi-axis robot) 12, and a power source 13. The remote welding robot 10 may further include other components.

[0018] The torch 11 is a heat source for welding. In the present embodiment, the welding apparatus 100 performs arc welding. In the present embodiment, the torch 11 generates an arc discharge to melt the welding target portion of the workpiece W. The arc welding may be, for example, TIG welding, plasma welding, gas metal arc welding, submerged arc welding, covered arc welding, self-shielded arc welding, or electrogas arc welding. In other embodiments, the welding apparatus 100 may perform welding other than arc welding, such as laser welding, electron beam welding, electroslag welding, brazing (soldering, brazing), gas welding, spraying, or plastic welding. The welding performed by the welding apparatus 100 is not limited to these. The heat source 11 can be a laser head, an electron gun, a welding rod, an electrode guide, a soldering iron, a gas torch, a spray gun, a heat pen, etc., depending on the type of welding to be performed.

[0019] The manipulator 12 holds the torch 11. The manipulator 12 moves the torch 11 based on a signal from the control device 20. For example, the manipulator 12 may be a multi-degree-of-freedom articulated robot. For example, the manipulator 12 may move the torch 11 with six degrees of freedom including the X direction, Y direction, Z direction, pitch direction, yaw direction, and roll direction.

[0020] For example, the manipulator 12 may include a plurality of motors for moving the torch 11. For example, the motor may be a servo motor, and the manipulator 12 may include a plurality of encoders S1. In the present embodiment, the encoder S1 is connected to a robot controller 22 (described later) in the control device 20 so as to be communicable by wire or wirelessly. The encoder S1 transmits measurement data to the robot controller 22.

[0021] Based on the measurement data from the encoder S1, the control device 20 can obtain the position of the origin of the torch 11 and the attitude of the torch 11. In other words, for example, when the shape of the workpiece W is constant and the workpiece W is arranged at a predetermined position, the control device 20 can detect, based on the measurement data from the encoder S1, that the origin of the torch 11 has reached the limits L1, L2, or L3 (see FIG. 2) of a predetermined allowable region A set with respect to the workpiece W. The allowable region A and the limits L1, L2, and L3 will be described in detail later. Therefore, in the present embodiment, the encoder S1 can function as a sensor for detecting that the torch 11 has reached the limits L1, L2, or L3.

[0022] Referring to FIG. 1, in this embodiment, the remote welding robot 10 includes a distance measuring sensor S2. For example, the distance measuring sensor S2 may be a LiDAR (Light Detection and Ranging), a laser radar, a laser sensor, a millimeter wave sensor, or an ultrasonic sensor. The distance measuring sensor S2 is not limited to these. In this embodiment, the distance measuring sensor S2 is connected to the PC21 (described later) in the control device 20 in a wired or wireless communicable manner. The distance measuring sensor S2 transmits measurement data to the PC21. For example, the distance measuring sensor S2 may be fixed at any position on the torch 11 where the distance measuring sensor S2 can measure the workpiece W, such as on the side surface of the torch 11.

[0023] Based on the measurement data from the distance measuring sensor S2, the control device 20 can measure the position of the workpiece W relative to the origin position of the torch 11. In other words, for example, when the shape of the workpiece W is constant and the workpiece W is arranged at a predetermined position, the control device 20 can detect that the origin of the torch 11 has reached the limit L1, L2, or L3 of the allowable region A based on the measurement data from the distance measuring sensor S2. Therefore, in this embodiment, the distance measuring sensor S2 can function as a sensor for detecting that the torch 11 has reached the limit L1, L2, or L3.

[0024] In this embodiment, the remote welding robot 10 includes a camera S3. For example, the camera S3 may include an image sensor such as a CMOS or a CCD. For example, the camera S3 may include a single camera. Also, for example, the camera S3 may include a plurality of cameras (for example, a stereo camera). In this embodiment, the camera S3 is connected to the PC21 in the control device 20 in a wired or wireless communicable manner. The camera S3 transmits images and videos to the PC21. For example, the camera S3 may be fixed at any position on the torch 11 where the camera S3 can photograph the workpiece W, such as on the side surface of the torch 11.

[0025] The control device 20 may extract that the torch 11 has reached the limits L1, L2 or L3 based on the image or video from the camera S3. For example, the control device 20 may be configured to extract a specific point on the workpiece W based on known image processing and measure the distance to the extracted point based on a plurality of images taken from different positions. In other words, the control device 20 can detect that the origin of the torch 11 has reached the limits L1, L2 or L3 of the permission area A based on the image or video from the camera S3. Therefore, in the present embodiment, the camera S3 can function as a sensor for detecting that the torch 11 has reached the limits L1, L2 or L3.

[0026] The welding apparatus 100 may include a camera (overhead camera) S4. For example, the camera S4 may include an image sensor such as a CMOS or a CCD. For example, the camera S4 may include a single camera. Also, for example, the camera S4 may include a plurality of cameras (for example, a stereo camera). In the present embodiment, the camera S4 is communicably connected to the PC21 among the control devices 20 by wire or wirelessly. The camera S4 transmits images and videos to the PC21. For example, the camera S4 may be fixed at any position capable of photographing the contact between the torch 11 and the workpiece W. The control device 20 may extract that the torch 11 has contacted the workpiece W based on the image or video from the camera S4.

[0027] The power source 13 supplies power to the torch 11. In the present embodiment, the power source 13 is communicably connected to the robot controller 22 among the control devices 20 by wire or wirelessly. The power source 13 adjusts the output of the arc discharge based on a signal from the robot controller 22.

[0028] The control device 20 controls the remote welding robot 10. The control device 20 may control the entire welding device 100. In the present embodiment, the control device 20 includes a PC 21, a robot controller 22, and a teaching pendant 23. The control device 20 may further include other components. Also, the control device 20 may not include at least one of the above components. For example, in other embodiments, the control device 20 may be implemented by a single computer.

[0029] Each of the PC 21, the robot controller 22, and the teaching pendant 23 includes components such as processors 21a, 22a, 23a and storage devices 21b, 22b, 23b, etc., and these components are connected to each other via a bus. Each of the PC 21, the robot controller 22, and the teaching pendant 23 may further include other components. For example, the processors 21a, 22a, 23a include a CPU (Central Processing Unit) etc. For example, the storage devices 21b, 22b, 23b include a hard disk, a ROM in which programs etc. are stored, and a RAM etc. as a work area. For example, the operations of each of the PC 21, the robot controller 22, and the teaching pendant 23 may be realized by having the processors 21a, 22a, 23a execute programs stored in the storage devices 21b, 22b, 23b.

[0030] The PC 21 is communicably connected to the robot controller 22 by wire or wirelessly. For example, the PC 21 may be connected to the robot controller 22 via a network such as the Internet. For example, the PC 21 is arranged at the location where the welder (operator) H is present.

[0031] The robot controller 22 is communicably connected to the manipulator 12 and the power source 13 of the remote welding robot 10, either wired or wirelessly. Also, the teaching pendant 23 is communicably connected to the robot controller 22, either wired or wirelessly. The robot controller 22 controls the remote welding robot 10 based on signals from the PC 21, the teaching pendant 23, and the input device 30.

[0032] The input device 30 receives inputs from the welder H for operating the remote welding robot 10. The input device 30 may further receive other inputs from the welder H regarding the remote welding robot 10 and the welding device 100. For example, the input device 30 may include at least one of a position input device and a speed input device. In the present embodiment, the input device 30 includes a haptic device 31 and a foot switch 32. The input device 30 may further include at least one of other input devices, such as a joystick, a button, a dial, a foot pedal, a touch panel, a smartphone, a tablet, a scroll wheel, a handle, and a motion controller. The input device 30 is not limited thereto.

[0033] For example, the haptic device 31 receives inputs from the welder H for moving the torch 11 in at least one direction among the X direction, the Y direction, the Z direction, the pitch direction, the yaw direction, the roll direction, and combinations of these directions.

[0034] The haptic device 31 is configured to apply a reaction force or vibration that stimulates the sense of force of the welder H to the welder H.

[0035] The haptic device 31 receives an input from the welder H to release the restriction on the movement of the torch 11 described later. For example, the haptic device 31 may include a button or a switch for receiving such an input. In other embodiments, the input device 30 may include another input device independent of the haptic device 31 for receiving such an input. In the present embodiment, the haptic device 31 is communicably connected to the PC 21, either wired or wirelessly.

[0036] For example, the foot switch 32 receives an input from the welder H to start melting. In the present embodiment, the foot switch 32 is communicably connected to the robot controller 22, either wired or wirelessly.

[0037] The display 40 shows various information output from the control device 20. For example, the display 40 may show an image or a video obtained by the camera S3. For example, the welder H may operate the haptic device 31 while viewing the image or video on the display 40 and remotely operate the manipulator 12. In the present embodiment, the display 40 is communicably connected to the PC 21, either wired or wirelessly.

[0038] Subsequently, the operation of the welding apparatus 100 will be described.

[0039] FIG. 2 is a schematic front view showing a predetermined allowable region A set for the work W. In FIG. 2, the allowable region A is surrounded by a broken line. In FIG. 2, the work W is viewed in the Y direction described later. In the example of FIG. 2, the work W includes a first work W1 and a second work W2. For example, each of the first work W1 and the second work W2 has, for example, a plate shape. In other embodiments, the first work W1 and the second work W2 may have a shape other than the plate shape. In the example of FIG. 2, butt welding between the first work W1 and the second work W2 is performed. In other embodiments, other welding other than butt welding may be performed.

[0040] The first workpiece W1 includes an inclined surface W11 at the welding target location. The second workpiece W2 includes an inclined surface W21 at the welding target location. The inclined surfaces W11 and W21 define a groove g. In the example of FIG. 2, the groove g is line-symmetric with respect to the boundary line between the inclined surfaces W11 and W21 (symmetric left and right in FIG. 2). In other embodiments, the groove g may be asymmetric with respect to the boundary line (asymmetric left and right in FIG. 2). The torch 11 is moved along the groove g to perform welding. Further, in the example of FIG. 2, the torch 11 is reciprocated in a direction perpendicular to the groove g to perform weaving E. Therefore, in the example of FIG. 2, the welder H moves the torch 11 generally periodically. The welder H moves the torch 11, for example, in a sine wave shape.

[0041] In the welding as described above, the welder H sets a permitted region A with respect to the workpiece W. In the present disclosure, the "permitted region" means a region where the heat source 11 is allowed to move with respect to the workpiece W. For example, in the "permitted region", the movement of the heat source 11 is not restricted, and no resistance force is applied to the heat source 11. Therefore, in the "permitted region", the precise operation of the welder H is not hindered, and the welder H can perform welding without burden. In the example of FIG. 2, the permitted region A prevents the torch 11 from deviating greatly from the groove g due to the weaving E.

[0042] Specifically, the first workpiece W1 and the second workpiece W2 are arranged such that the end surface W12 of the first workpiece W1 and the end surface W22 of the second workpiece W2 are flush with each other. A coordinate system is set for the workpiece W. In the example of FIG. 2, the origin P0 of the workpiece W is set at one corner on the end surface W12. Specifically, the origin P0 is located at the lower end of the side away from the groove g on the end surface W12. The position of the origin P0 is not limited to this. In other embodiments, for example, the origin P0 may be set at another point on the first workpiece W1 or the second workpiece W2, or at any point on a table (not shown) on which the workpiece W is arranged.

[0043] In the example of FIG. 2, the vertical direction is set as the Z direction. The directions along the end faces W12 and W22 are set as the X direction. The direction perpendicular to the X direction and the Z direction is set as the Y direction. The end faces W12 and W22 are perpendicular to the Y-axis direction and extend along the XZ plane. The groove g extends along the Y direction.

[0044] For the torch 11, an origin T0 is set. The origin T0 may be set at any point on the torch 11. For example, the origin T0 may be set at a point on the axis of the torch 11, such as the tip of the wire. In other embodiments, other points on the wire or the nozzle may be used as the origin T0. Also, for example, when the welding apparatus 100 performs TIG welding, any point on the electrode or the nozzle may be used as the origin of the heat source 11. In the example of FIG. 2, a single origin is set for the heat source 11. In other embodiments, a plurality of origins may be set for the heat source 11.

[0045] The remote welding robot 10 moves the torch 11 along the groove g, that is, along the Y direction. Also, the remote welding robot 10 reciprocates the torch 11 in the X direction in order to perform the weaving E.

[0046] In the welding as described above, a first limit L1, a second limit L2, and a third limit L3 are set to define the allowable region A.

[0047] For example, the first limit L1 and the second limit L2 define the allowable region A in the X direction. For example, the first limit L1 and the second limit L2 define the allowable region A so as to include the center of the groove g in the X direction.

[0048] For example, the first limit L1 defines the lower limit of the allowable region A in the X direction. For example, the first limit L1 may be set on the inclined surface W11 of the first workpiece W1. For example, the first limit L1 may be set at the center in the X direction on the inclined surface W11. The point P1 is the position of the first limit L1 on the end face W12 (X 1,0,0). The first limit L1 extends parallel to the YZ plane. The position of the first limit L1 is not limited to this and may be set at other positions on the first workpiece W1.

[0049] For example, the second limit L2 defines the upper limit of the allowable region A in the X direction. For example, the second limit L2 may be set on the inclined surface W21 of the second workpiece W2. For example, the second limit L2 may be set at the center in the X direction on the inclined surface W21. The point P2 is the position of the second limit L2 on the end surface W22 (X 2 ,0,0). X 2 is larger than X 1 . The second limit L2 extends parallel to the YZ plane. The position of the second limit L2 is not limited to this and may be set at other positions on the second workpiece W2.

[0050] For example, the third limit L3 defines the allowable region A in the Z direction. For example, the third limit L3 defines the lower limit of the allowable region A in the Z direction. For example, the third limit L3 may be set on the inclined surface W11 or the inclined surface W21. For example, the third limit L3 may be set at the center in the Z direction on the inclined surface W11 or the inclined surface W21. The point P3 is the position of the third limit L3 on the end surface W12 (0,0,Z 1 ). The third limit L3 extends parallel to the XY plane. The position of the third limit L3 is not limited to this and may be set at other positions on the first workpiece W1 or the second workpiece W2.

[0051] In the example of FIG. 2, the space surrounded by the first limit L1, the second limit L2, and the third limit L3 is defined as the allowable region A. In the example of FIG. 2, the upper limit in the Z direction is not defined. In other embodiments, the upper limit in the Z direction may be defined.

[0052] The allowable region A may be set in various ways.

[0053] For example, the allowable area A may be set by teaching using the teaching pendant 23. For example, in teaching, instead of the torch 11, a touch probe (not shown) may be held by the manipulator 12. For example, when the touch probe contacts the work W, the position of the touch probe measured by the encoder S1 may be used for setting at least one of the limits L1, L2, and L3.

[0054] Alternatively or additionally, for example, the allowable area A may be set on the PC21 based on at least one of the measurement data from the distance measuring sensor S2 and the image from the camera S3. For example, the welder H may select an arbitrary point on the work W in the image from the camera S3 on the PC21, and the coordinates of the selected point may be used for setting at least one of the limits L1, L2, and L3.

[0055] Alternatively or additionally, for example, the allowable area A may be set on the PC21 using the CAD model of the work W. For example, the welder H may select an arbitrary point on the CAD model of the work W on the PC21, and the coordinates of the selected point may be used for setting at least one of the limits L1, L2, and L3. In this case, the data from the encoder S1, the distance measuring sensor S2, and the camera S3 may not be used for setting the allowable area A.

[0056] The allowable area A may be stored in at least one of the storage devices 21b, 22b, and 23b.

[0057] Figure 3 is a schematic plan view showing an example of the restrictions imposed on the movement of the heat source 11. In Figure 3, the work W is viewed in the Z direction. Arrow M H indicates the input from the welder H to the haptic device 31, including weaving. Arrow M T is the input M H based on which the operation of the torch 11 is shown. In the example of Figure 3, operation M T shows the operation of the origin T0 of the torch 11.

[0058] Input M H If it is larger than intended, it is detected by at least one of the encoder S1, the distance measuring sensor S2, and the camera S3 that the torch 11 has reached the first limit L1 and the second limit L2. In this case, the robot controller 22 imposes a restriction on the movement of the torch 11 in the X direction beyond the first limit L1 and the second limit L2.

[0059] Specifically, in the example of FIG. 3, the PC 21 sends a command to the haptic device 31 so as to apply a resistance force to the movement of the torch 11 in the direction beyond the first limit L1 and the second limit L2. The output value of the haptic device 31 to the PC 21 at this time will be restricted as compared with the case where no resistance force is applied. By controlling the manipulator 12 by the robot controller 22 with this restricted output value, a restriction can be imposed on the movement of the torch 11. That is, in the example of FIG. 3, the flow of (i) the PC 21 sets a restriction → (ii) the PC 21 restricts the operation of the haptic device 31 → (iii) the robot controller 22 controls the manipulator 12 with the output value restricted by the haptic device 31 is executed. However, both the flow of (i) the PC 21 sets a restriction → (iii) the robot controller 22 controls the manipulator 12 with the restricted output value, and the flow of (i) the PC 21 sets a restriction → (ii) the PC 21 restricts the operation of the haptic device 31 may be executed in parallel.

[0060] For example, when the origin T0 of the torch 11 reaches the second limit L2 from the allowed area A, the PC 21 sends a command to the haptic device 31 to apply a negative reaction force in the X direction to the haptic device 31. When the origin T0 of the torch 11 reaches the first limit L1 from the allowed area A, the PC 21 sends a command to the haptic device 31 to apply a positive reaction force in the X direction to the manipulator 12. For example, the reaction force may be a constant value. Alternatively, the reaction force may be an elastic force and may increase as the torch 11 moves away from the first limit L1 and the second limit L2. Alternatively, the reaction force may be a viscous force.

[0061] Fig. 7 is a schematic graph showing an example of a restriction imposed on the movement of a heat source. In Fig. 7 and the following Figs. 8 and 9, the horizontal axis indicates the position of the torch 11 in the X direction, and the vertical axis indicates the reaction force F. As shown in Fig. 7, for example, when the reaction force F is a constant value, the reaction force F may be expressed by the following formulas (1) to (3). F=B (X <X 1 ) · · · (1) F=0 (X 1 ≦X≦X 2 ) · · · (2) F=-B (X>X 2 ) · · · (3) however, B: A constant positive value

[0062] In the examples of formulas (1) to (3), (X <X 1 ) and (X>X 2 ) the same value of B is used for both regions (i.e. the reaction force is X 1 and X 2 The center point X between M In another embodiment, for example, (X <X 1 ) and (X>X 2 ) different values ​​may be used (i.e. the reaction force is MBased on this, it is asymmetric). In this case, for example, for the asymmetric opening g, the reaction force F can be set according to the opening angle.

[0063] FIG. 8 is a schematic graph showing another example of the restriction imposed on the movement of the heat source. As shown in FIG. 8, for example, when the reaction force F is an elastic force, the reaction force F may be represented by the following equations (4) to (6). F = -k(X - X 1 )(X < X 1 ) ··· (4) F = 0 (X 1 ≤ X ≤ X 2 ) ··· (5) F = -k(X - X 2 )(X > X 2 ) ··· (6) However, k: Elastic coefficient

[0064] In the examples of equations (4) to (6), the same elastic coefficient k is used for both the region of (X < X 1 ) and the region of (X > X 2 )(that is, the reaction force is point-symmetric with respect to the center point X M ). In other embodiments, for example, different elastic coefficients may be used for the region of (X < X 1 ) and the region of (X > X 2 )(that is, the reaction force is asymmetric with respect to the center point X M ). In this case, for example, for the asymmetric opening g, the reaction force F can be set according to the opening angle.

[0065] FIG. 9 is a schematic graph showing still another example of the restriction imposed on the movement of the heat source. As shown in FIG. 9, for example, when the reaction force F is the resultant of a constant force and an elastic force, the reaction force F may be represented by the following equations (7) to (9). F = -k(X - X 1 ) + B (X < X 1 ) ··· (7) F = 0 (X 1 ≤ X ≤ X 2 ) ··· (8) F = -k(X - X2 ) - B (X > X 2 ) ··· (9)

[0066] In the examples of formulas (7) to (9), for both the region of (X < X 1 ) and the region of (X > X 2 ), the same value B and the same elastic coefficient k are used (i.e., the reaction force is point - symmetric with respect to the center point X M ). In other embodiments, for example, different values and different elastic coefficients may be used for the region of (X < X 1 ) and the region of (X > X 2 ) (i.e., the reaction force is asymmetric with respect to the center point X M ). In this case, for example, for an asymmetric opening g, the reaction force F can be set according to the opening angle.

[0067] For example, when the reaction force F is a viscous force, the reaction force F may be represented by the following formulas (10) to (12). F = -η(dx / dt) (X < X 1 ) ··· (10) F = 0 (X 1 ≤ X ≤ X 2 ) ··· (11) F = -η(dx / dt) (X > X 2 ) ··· (12) However, η: Viscous resistance coefficient

[0068] The formula representing the reaction force F is not limited to formulas (1) to (12).

[0069] Alternatively or additionally, the reaction force may vary (vibrate). According to the above configuration, although the moving speed of the torch 11 in the direction exceeding the first limit L1 and the second limit L2 is reduced, the origin T0 of the torch 11 can move beyond the first limit L1 and the second limit L2 to a position outside the allowable region A (the position indicated by the dashed circle). For example, when the reaction force F is very large (e.g., k = ∞), the movement of the torch 11 in the direction exceeding the first limit L1 and the second limit L2 can be prohibited, similar to the example of FIG. 4 below. Also, according to the above configuration, in the allowable region A (X 1 ≦X≦X 2 ), no restriction is imposed on the movement of the torch 11.

[0070] FIG. 4 is a schematic plan view showing another example of the restrictions imposed on the movement of the heat source 11. In the example of FIG. 4, the robot controller 22 sends a command to the manipulator 12 to prohibit the movement of the torch 11 in the direction exceeding the first limit L1 and the second limit L2. In the example of FIG. 4, both the flow of (i) the PC21 setting the restriction → (iii) the robot controller 22 controlling the manipulator 12 with the restricted output value and the flow of (i) the PC21 setting the restriction → (ii) the PC21 restricting the operation of the haptic device 31 are executed in parallel. For example, when the origin T0 of the torch 11 reaches the second limit L2 from the allowable region A, the robot controller 22 prohibits the positive movement of the manipulator 12 in the X direction beyond the second limit L2. Also, when the origin T0 of the torch 11 reaches the first limit L1 from the allowable region A, the robot controller 22 prohibits the negative movement of the manipulator 12 in the X direction beyond the first limit L1. Therefore, the origin T0 of the torch 11 cannot move beyond the first limit L1 and the second limit L2 to a position outside the allowable region A.

[0071] Also, when it is detected that the torch 11 has reached the first limit L1 or the second limit L2, the PC21 sends a command to the haptic device 31 to lock the input to the haptic device 31 in that direction. With such a configuration as well, the welder H can recognize that the input M H is larger than intended. Also, when it is detected that the torch 11 has reached the first limit L1 and the second limit L2, the PC21 may send a command to the haptic device 31 to apply a reaction force to the welder H that stimulates the force sense of the welder H. The reaction force may be a constant force, an elastic force, a viscous force, or a vibration. According to such a configuration, the welder H can recognize that the input M H is larger than intended and that the operation of the robot is restricted.

[0072] FIG. 5 is a schematic plan view showing yet another example of the restrictions imposed on the movement of the heat source 11. In the example of FIG. 5, the robot controller 22 sends a command to the manipulator 12 to multiply the moving speed of the torch 11 in the direction exceeding the first limit L1 and the second limit L2. In the example of FIG. 5, both the flow of (i) the PC21 setting the restriction → (iii) the robot controller 22 controlling the manipulator 12 with the restricted output value and the flow of (i) the PC21 setting the restriction → (ii) the PC21 restricting the operation of the haptic device 31 are executed in parallel. For example, when the origin T0 of the torch 11 reaches the first limit L1 or the second limit L2 from the permission region A, the robot controller 22 may multiply the current moving speed of the manipulator 12 in the X direction by a magnification factor α that is greater than 0 and less than 1. Also, for example, when a magnification factor γ is applied to the output from the robot controller 22 to the manipulator 12 in the permission region A, the magnification factor α may be further multiplied by the magnification factor γ.

[0073] FIG. 10 is a schematic graph showing yet another example of the restrictions imposed on the movement of the heat source. In FIG. 10 and the following FIG. 11, the horizontal axis indicates the position of the torch 11 in the X direction, and the vertical axis indicates the magnification α. As shown in FIG. 10, for example, when the magnification α is a function of X, the output speed V of the torch 11 1 may be represented by the following equation (13). V 1 = α × V 0 ···(13) α = γ (X 1 ≦ X ≦ X 2 ) α = f(X) (X < X 1 ) α = g(X) (X > X 2 ) However, V 0 : Input speed γ: Constant magnification f(X): f(X 1 ) ≦ γ, and a function that decreases as X decreases from X 1 g(X): g(X 2 ) ≦ γ, and a function that decreases as X increases from X 2

[0074] f(X) and g(X) may be line-symmetric or non-symmetric with respect to the center line parallel to the vertical axis passing through the center point X M . Also, the output speed V 1 may be discontinuous when crossing X 1 (i.e., f(X 1 ) < γ may be possible). Alternatively, the output speed V 1 may be continuous when crossing X 1 (i.e., f(X 1 ) = γ may be possible). Similarly, the output speed V 1 may be discontinuous when crossing X 2 (i.e., g(X 2 ) < γ may be possible). Alternatively, the output speed V 1 may be continuous when crossing X 2 ​​When spanning, it may be continuous (i.e., g(X 2 ) = γ may also be the case).

[0075] Figure 11 is a schematic graph showing yet another example of the restrictions imposed on the movement of the heat source. As shown in Figure 11, for example, when the magnification factor α is constant, the output speed V 1 of the torch 11 may be represented by the following equation (14). V 1 = α × V 0 ···(14) α = γ (X 1 ≦ X ≦ X 2 ) α = β (X < X 1 ) α = β (X > X 2 ) However,[[]] β: A constant magnification factor smaller than γ, greater than 0 and smaller than 1

[0076] In the example of equation (14), the same magnification factor β is used for both the region of (X < X 1 ) and the region of (X > X 2 ) (i.e., the magnification factor α is line-symmetric with respect to the center line parallel to the vertical axis passing through the center point X M ). In other embodiments, for example, different magnification factors may be used for the region of (X < X 1 ) and the region of (X > X 2 ) (i.e., the magnification factor α is asymmetric with respect to the above center line). In this case, for example, for an asymmetric opening g, the reaction force F can be set according to the opening angle.[[]]

[0077] The equation representing the magnification factor α is not limited to equation (13) or (14).[[]]

[0078] According to the above configuration, although the moving speed of the torch 11 in the direction exceeding the first limit L1 and the second limit L2 is reduced, the origin T0 of the torch 11 can move beyond the first limit L1 and the second limit L2 to a position outside the allowable region A (the position indicated by the dashed circle). For example, when α = 0, similar to the example of FIG. 4 above, the movement of the torch 11 in the direction exceeding the first limit L1 and the second limit L2 can be prohibited. Also, according to the above configuration, in the allowable region A (X 1 ≦ X ≦ X 2 ), no restriction is provided for the movement of the torch 11.

[0079] Further, when it is detected that the torch 11 has reached the first limit L1 and the second limit L2, the PC21, similar to the example of FIG. 3, sends a command to the haptic device 31 to apply a reaction force that stimulates the force sense of the welder H, such as a constant force, an elastic force, a viscous force, or vibration, to the welder H. For example, the PC21 sends a command to the haptic device 31 to apply a reaction force in the opposite direction to the input M H . According to such a configuration, the welder H can recognize that the input M H is larger than intended.

[0080] FIG. 6 is a schematic plan view showing still another example of the restrictions applied to the movement of the heat source 11. In the example of FIG. 6, in addition to the first limit L1 and the second limit L2 in the X direction, a fourth limit L4 and a fifth limit L5 are set.

[0081] For example, the fourth limit L4 defines the second lower limit of the allowable region A in the X direction. For example, the fourth limit L4 may be set at the upper end of the inclined surface W11 of the first workpiece W1. The point P4 indicates the position (X 4 , 0, 0) of the fourth limit L4 on the end surface W12. X 4 is X 1is smaller. The fourth limit L4 extends parallel to the YZ plane. The position of the fourth limit L4 is not limited to this and may be set at other positions on the first workpiece W1.

[0082] For example, the fifth limit L5 defines the second upper limit of the allowable region A in the X direction. For example, the fifth limit L5 may be set at the upper end of the inclined surface W21 of the second workpiece W2. The point P5 indicates the position of the fifth limit L5 on the end surface W22 (X 5 , 0, 0). X 5 is larger than X 2 . The fifth limit L5 extends parallel to the YZ plane. The position of the fifth limit L5 is not limited to this and may be set at other positions on the second workpiece W2.

[0083] In the example of FIG. 6, the robot controller 22 applies a resistance force to the movement of the torch 11 in a direction exceeding the first limit L1 and the second limit L2, and sends a command to the manipulator 12 to prohibit the movement of the torch 11 in a direction exceeding the fourth limit L4 and the fifth limit L5.

[0084] For example, when the origin T0 of the torch 11 reaches the second limit L2 from the allowable region A, the robot controller 22 sends a command to the manipulator 12 so that a negative reaction force is applied to the manipulator 12 in the X direction. Therefore, although the moving speed of the origin T0 of the torch 11 in a direction exceeding the second limit L2 is reduced, the origin T0 of the torch 11 can move beyond the second limit L2 to a position outside the allowable region A (the position indicated by the broken-line circle). However, when the origin T0 of the torch 11 further reaches the fifth limit L5 from the second limit L2, the robot controller 22 prohibits the positive movement of the manipulator 12 in the X direction exceeding the fifth limit L5. Therefore, the origin T0 of the torch 11 cannot move beyond the second limit L2 to exceed the fifth limit L5.

[0085] Also, when the origin T0 of the torch 11 reaches the first limit L1 from the allowable region A, the robot controller 22 sends a command to the manipulator 12 so that a positive reaction force in the X direction is applied to the manipulator 12. Therefore, although the moving speed of the torch 11 in the direction exceeding the first limit L1 is reduced, the origin T0 of the torch 11 can move beyond the first limit L1 to a position outside the allowable region A (the position indicated by the broken-line circle). However, when the origin T0 of the torch 11 further reaches the fourth limit L4 from the first limit L1, the robot controller 22 prohibits the negative-direction movement of the manipulator 12 in the X direction exceeding the fourth limit L4. Therefore, the origin T0 of the torch 11 cannot move beyond the first limit L1 to exceed the fourth limit L4.

[0086] Also, when it is detected that the torch 11 has reached the first limit L1 and the second limit L2, the PC 21 sends a command to the haptic device 31 so as to apply a reaction force that stimulates the force sense of the welder H, such as a constant force, an elastic force, a viscous force, or vibration, to the welder H. Further, when it is detected that the torch 11 has reached the fourth limit L4 or the fifth limit L5, the PC 21 sends a command to the haptic device 31 to lock the input to the haptic device 31 in that direction. According to such a configuration, the welder H can gradually recognize that the input M H is larger than intended.

[0087] In the examples of FIGS. 3 to 6, the restriction on the movement of the torch 11 in the X direction when the torch 11 reaches the limits L1, L2, L4, and L5 in the X direction has been described. When the torch 11 reaches the limit L3 in the Z direction, similar restrictions may be imposed on the movement of the torch 11 in the Z direction.

[0088] In the examples of FIGS. 3 to 6, the restriction on the movement of the torch 11 may reduce the working efficiency. As described above, in the present embodiment, the haptic device 31 includes a button or a switch for releasing the restriction on the movement of the torch 11. The welder H may release the restriction on the movement of the torch 11 by pressing this button or switch. According to such a configuration, a decrease in working efficiency can be suppressed.

[0089] The welding apparatus 100 as described above includes a welding torch 11, a manipulator 12 that holds the torch 11 and moves the torch 11, an encoder S1, a distance measuring sensor S2, and a camera S3 that detect that the torch 11 has reached the limits L1, L2, L3, L4, and L5 of a predetermined allowable region A set for the work W, a haptic device 31 and a foot switch 32 that receive an input from the welder H for operating the manipulator 12, and a control device 20 of the manipulator 12. The control device 20 is configured to impose a restriction on the movement of the torch 11 in a direction exceeding the corresponding limit when it is detected by at least one of the encoder S1, the distance measuring sensor S2, and the camera S3 that the torch 11 has reached the limit L1, L2, L3, L4, or L5 during the operation of the manipulator 12 based on the input from the welder H to the haptic device 31 and the foot switch 32. According to such a configuration, the movement of the torch 11 outside the intended region A can be suppressed.

[0090] Further, in the welding apparatus 100, the control device 20 sets the allowable region A based on data from at least one of the encoder S1, the distance measuring sensor S2, and the camera S3. According to such a configuration, the allowable region A can be adjusted based on measurement data regarding the actual work W.

[0091] Also, in one example, the control device 20 sends a command to the manipulator 12 to reduce the moving speed of the torch 11 in a direction exceeding the corresponding limit as a restriction.

[0092] In this case, the control device 20 may send a command to the manipulator 12 to apply a resistance force to the movement of the torch 11 in a direction exceeding the corresponding limit, as a restriction. If the movement of the torch 11 in a direction exceeding the corresponding limit is completely prohibited, in some cases, the working efficiency may decrease. However, according to the above configuration, since the movement of the torch 11 in a direction exceeding the corresponding limit is not completely prohibited, a decrease in working efficiency can be suppressed.

[0093] Also, in the above case, the control device 20 may send a command to the manipulator 12 to multiply the moving speed of the torch 11 in a direction exceeding the corresponding limit, as a restriction. Even with such a configuration, since the movement of the torch 11 in a direction exceeding the corresponding limit is not completely prohibited, a decrease in working efficiency can be suppressed.

[0094] Furthermore, in still another example, the control device 20 sends a command to the manipulator 12 to prohibit the movement of the torch 11 in a direction exceeding the corresponding limit, as a restriction. According to such a configuration, the movement of the torch 11 outside the intended area A can be prohibited.

[0095] Also, in the welding device 100, the haptic device 31 is configured to receive an input from the welder H to release the restriction on the movement of the torch 11, and the control device 20 releases the restriction when the haptic device 31 receives an input to release the restriction. According to such a configuration, a decrease in working efficiency can be suppressed.

[0096] As described above, the embodiments have been described with reference to the accompanying drawings, but the present disclosure is not limited to the above embodiments. It is obvious that those skilled in the art can conceive of various modification examples or correction examples within the scope described in the claims, and it is naturally understood that those also belong to the technical scope of the present disclosure. Also, the steps of the method of the above embodiments do not have to be performed in the above order, and may be performed in a different order as long as there is no technical contradiction.

[0097] For example, in the above embodiment, the weaving E includes the reciprocating motion of the torch 11 in the X direction. In other embodiments, the weaving E may include the reciprocating motion or rotational motion of the torch 11 in other directions.

[0098] Also, for example, in the above embodiment, as sensors for detecting that the torch 11 has reached the limits L1, L2, L3, L4, or L5, the encoder S1, the distance measuring sensor S2, and the camera S3 are used. In other embodiments, one or two of the encoder S1, the distance measuring sensor S2, and the camera S3 may be used as such sensors. That is, at least one of the encoder S1, the distance measuring sensor S2, and the camera S3 may be used as such sensors. Also, in other embodiments, other types of sensors may be used as sensors for detecting that the torch 11 has reached the limits L1, L2, L3, L4, or L5.

[0099] Also, for example, in the example of FIG. 6, as a restriction on the movement of the torch 11, a combination of a resistance force to the movement and a prohibition of the movement is used (that is, a combination of the examples of FIGS. 3 and 4). In other embodiments, for example, two or three of a resistance force to the movement, a viscous force, an integration of a magnification with respect to the movement speed, and a prohibition of the movement and vibration may be combined. Also, the restriction on the movement of the torch 11 is not limited to these.

[0100] For example, in FIG. 6, different elastic coefficients k 1 , k 2 may be combined. FIG. 12 is a schematic graph showing still another example of the restriction applied to the movement of the heat source. In FIG. 12 and the following FIG. 13, the horizontal axis indicates the position of the torch 11 in the X direction, and the vertical axis indicates the reaction force F. As shown in FIG. 12, when different elastic coefficients k 1 , k 2 are combined, for example, the reaction force F may be represented by the following formulas (15) to (19). F = -k 2(XX 4 )-k 1 (X 4 -X 1 )+j(X <X 4 ) · · · (15) F=-k 1 (XX 1 ) (X 4 ≦X <X 1 ) · · · (16) F=0 (X 1 ≦X≦X 2 ) · · · (17) F=-k 1 (XX 2 ) (X 2 <X≦X 5 ) · · · (18) F=-k 2 (XX 5 )-k 1 (X 5 -X 2 )-j (X>X 5 ) · · · (19) however, j: A constant greater than or equal to 0

[0101] In the example of equations (15) to (19), (X <X 1 ) and (X>X 2 ) region, the same elastic coefficient k 1 ,k 2 is used (i.e., the reaction force is X 1 and X 2 center point M In another embodiment, for example, (X <X 1 ) and (X>X 2 ) different elastic coefficients may be used (i.e. the reaction force is M Asymmetrical based on the groove angle. In this case, for example, for an asymmetric groove g, the reaction force F can be set according to the groove angle. Note that, for example, when the reaction force F is very large (for example, k 2 =∞), movement of the torch 11 in a direction beyond the fourth limit L4 and the fifth limit L5 can be prohibited.

[0102] Also, for example, in FIG. 6, different resistances B, -kX may be combined. FIG. 13 is a schematic graph showing still another example of the restrictions imposed on the movement of the heat source. As shown in FIG. 13, when different resistances B, -kX are combined, for example, the reaction force F may be represented by the following equations (20) to (24). F = B(X < X 4 ) ··· (20) F = -k(X - X 1 ) (X 4 ≦ X < X 1 ) ··· (21) F = 0 (X 1 ≦ X ≦ X 2 ) ··· (22) F = -k(X - X 2 ) (X 2 < X ≦ X 5 ) ··· (23) F = -B(X > X 5 ) ··· (24)

[0103] In the examples of equations (20) to (24), the same resistances B, -kX are used for both the region (X < X 1 ) and the region (X > X 2 ) (i.e., the reaction force is point-symmetric with respect to the center point X M ). In other embodiments, for example, different resistances may be used for the region (X < X 1 ) and the region (X > X 2 ) (i.e., the reaction force is asymmetric with respect to the center point X M ). In this case, for example, for an asymmetric opening g, the reaction force F can be set according to the opening angle. Note that, for example, when the reaction force F is very large (e.g., B = ∞), the movement of the torch 11 in the direction exceeding the fourth limit L4 and the fifth limit L5 can be prohibited.

[0104] The combination of restrictions on the movement of the torch 11 is not limited to equations (15) to (24).

[0105] Also, for example, in the examples of FIGS. 3, 4, 5, and 6, the control device 20 may indicate to the welder H that the input M is greater than intended by sound or a display on the display 40 instead of or in addition to the force or tactile stimulus from the haptic device 31 to the welder H. H It may also indicate to the welder H that it is larger than intended.

Explanation of Signs

[0106] 11 Torch (heat source) 12 Manipulator (multi-axis robot) 20 Control device 30 Input device 100 Welding device A Permission area H Welder (operator) L1 First limit L2 Second limit L3 Third limit L4 Fourth limit L5 Fifth limit S1 Encoder (sensor) S2 Distance measuring sensor (sensor) S3 Camera (sensor) W Workpiece

Claims

1. A heat source for welding; a multi-axis robot that holds the heat source and moves the heat source; A sensor for detecting when the heat source reaches a limit of a predetermined allowable range set for the workpiece; an input device that receives an input for operating the multi-axis robot from an operator; The control device for the multi-axis robot, The control device includes: When the sensor detects that the heat source has reached the limit during operation of the multi-axis robot based on the input from the operator to the input device, a restriction is imposed on a movement of the heat source in a direction exceeding the limit; A control device configured to execute the A welding device comprising:

2. The welding device of claim 1 , wherein the controller sets the allowed region based on data from the sensor.

3. The welding device according to claim 1 or 2, wherein the control device sends a command to the multi-axis robot to reduce a moving speed of the heat source in a direction exceeding the limit as the restriction.

4. The welding device of claim 3 , wherein the control device sends a command to the multi-axis robot to apply a resistance force to the movement of the heat source in a direction exceeding the limit as the restriction.

5. The welding device according to claim 3 , wherein the control device sends a command to the multi-axis robot to multiply the moving speed of the heat source in a direction exceeding the limit by a factor of 10 as the restriction.

6. The welding device according to claim 1 or 2, wherein the control device sends a command to the multi-axis robot to prohibit movement of the heat source in a direction exceeding the limit as the restriction.

7. the input device receives an input for releasing the restriction from the worker, The welding device according to claim 1 , wherein the control device releases the restriction when the input device receives the input for releasing the restriction.

8. the input device receives an input for releasing the restriction from the worker, The welding device according to claim 3 , wherein the control device releases the restriction when the input device receives the input for releasing the restriction.

9. the input device receives an input for releasing the restriction from the worker, The welding apparatus according to claim 4, wherein the control device releases the restriction when the input device receives the input for releasing the restriction.

10. The input device receives an input for releasing the restriction from the operator, The welding apparatus according to claim 5, wherein the control device releases the restriction when the input device receives the input for releasing the restriction.

11. The input device receives an input for releasing the restriction from the operator, The welding apparatus according to claim 6, wherein the control device releases the restriction when the input device receives the input for releasing the restriction.

Images