Control device

Abstract

To efficiently grind weld bead.SOLUTION: A control device includes: a path specification section that specifies a teaching path serving as a criterion of a path of a grinding section for causing the grinding section to grind weld bead of a base material; and a control section that controls a robot having the grinding section installed therein to enable a weaving operation on the basis of a grinding condition related to the weaving operation for grinding the weld bead in an intersection direction intersecting with the teaching path by using the teaching path acquired on the basis of an operation input from a user as a criterion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a control device. [Background technology]

[0002] If the weld joint is left as it is with respect to the base material, the fatigue strength of the weld joint will decrease. The weld bead grinding device automatically grinds off the excess weld bead in order to prevent the fatigue strength of the weld joint from decreasing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-288789 Summary of the Invention [Problem to be solved by the invention]

[0004] The weld bead grinding device described in Patent Document 1 includes a grinding means and a distance measurement means. The distance measurement means measures the surface shape of the workpiece straddling the weld bead at at least two locations and measures the distance between the two locations. Based on the surface shape measurement results, the grinding means approximates the center of the weld bead to a straight line and grinds the weld bead along the straight line. This allows the weld bead grinding device to automatically grind the weld bead, which is made by butting plate-shaped base materials, to a substantially flush surface.

[0005] However, the weld bead grinding device described in Patent Document 1 requires multiple grinding operations for a weld bead having a wide width, which causes a problem of reduced efficiency in the grinding operation.

[0006] The present invention has been made to solve such problems, and has an object to make it possible to efficiently grind weld beads. [Means for solving the problem]

[0007] A control device according to one aspect of the present invention includes: a path specifying unit that specifies a teaching path that is a reference for a path of a grinding unit to cause the grinding unit to grind a weld bead of a base material; and a control unit that controls a robot on which the grinding unit is installed to enable the weaving operation based on grinding conditions related to a weaving operation for grinding the weld bead in an intersecting direction intersecting the teaching path with the teaching path as a reference, the weaving operation being acquired based on an operation input by a user. [Effects of the Invention]

[0008] According to the present invention, it is possible to efficiently grind the weld bead. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a side view showing a schematic configuration of a grinding system. [Figure 2] FIG. 10 is a diagram showing grinding condition information D131a. [Figure 3] FIG. 10 is a diagram showing an example of a grinding condition setting screen T10. [Figure 4] FIG. 10 is a diagram showing an example of a trajectory of a grinding tool in a weaving operation. [Figure 5] 10A and 10B are diagrams showing examples of the trajectory of the grinding tool that changes depending on the setting conditions of the weaving operation. [Figure 6] 10 is a flowchart showing a flow of a processing procedure of the grinding system. [Figure 7] FIG. 2 illustrates an example of a hardware configuration of a computer. DETAILED DESCRIPTION OF THE INVENTION

[0010] ===Configuration of Grinding System 10=== The configuration of the grinding system 100 will be described with reference to Fig. 1. Fig. 1 is a side view showing the schematic configuration of the grinding system 100.

[0011] Grinding system 100 is a system that grinds, for example, a weld bead that has been built up and welded onto a base material. Grinding system 100 can change the grinding operation conditions (hereinafter referred to as "grinding conditions") depending on the length and thickness of the weld bead.

[0012] The grinding conditions are, for example, conditions related to the weaving operation of grinding tool 120 when grinding a weld bead with grinding portion 123 of grinding tool 120. The weaving operation is an operation for grinding a weld bead while operating in a specific pattern, such as by performing a swing operation in an intersecting direction that intersects with taught path CS1, which will be described later, based on taught path CS1.

[0013] In this way, the grinding system 100 is capable of performing various weaving operations in the grinding process on the weld bead, thereby enabling the weld bead to be ground efficiently.

[0014] Specifically, grinding system 100 grinds any location on the weld bead multiple times using a weaving operation, so that grinding unit 123 can grind the weld bead multiple times at a small inclination with respect to the weld bead, rather than grinding it in one go at a large inclination with respect to the weld bead. As a result, grinding system 100 can ensure a sufficient amount of grinding while making the ground surface of the weld bead flatter than when the inclination is large.

[0015] Furthermore, whereas in the past, some parts of the grinding section 123 generated a lot of heat and were subject to severe wear, the grinding system 100 can reduce the inclination of the grinding section 123, thereby making the wear of the grinding section 123 uniform, thereby reducing costs.

[0016] The grinding system 100 may be configured to be able to grind by smoothly changing the grinding conditions in each region of the weld bead.

[0017] As shown in FIG. 1, the grinding system 100 includes, for example, a robot 110, a grinding tool 120, and a control device 130. In the grinding system 100, the control device 130 is configured to be able to control the robot 110 and the grinding tool 120 based on grinding conditions. Although the description has been given assuming that the robot 110, the grinding tool 120, and the control device 130 are configured as separate devices, these devices may be configured as a single device, or any two devices may be configured as a single device. Furthermore, the control device 130 may be configured such that a control device for controlling the robot 110 and a control device for controlling the grinding tool 120 are provided separately.

[0018] That is, in grinding system 100, control device 130 enables the operation of robot 110 and grinding tool 120 to be synchronized to grind the weld bead. As a result, in grinding system 100, control device 130 can centrally control robot 110 and grinding tool 120 without sending a large number of control signals from robot 110 to grinding tool 120, making system design easier.

[0019] The robot 110 is a robot that includes an articulated arm mounted on a base member that is fixed to, for example, a factory floor, and a grinding tool 120 attached to the tip of the articulated arm. The robot 110 grinds the weld bead by pressing a grinding portion 123 of the grinding tool 120 against the weld bead. The robot 100 can perform various tasks, such as assembling parts, welding, and cutting, depending on the type of end effector. The configuration of the robot 100 is well known, so a detailed description thereof will be omitted.

[0020] Robot 110 can perform a weaving motion of grinding tool 120 based on, for example, grinding conditions. When grinding a weld bead, robot 110 sets, via control device 130 based on a user's operational input, for example, a path along the weld bead along which grinding tool 120 passes (hereinafter referred to as "taught path CS1"). Taught path CS1 is, for example, a path that follows the center of the weld bead from one end to the other end of the weld bead. Furthermore, taught path CS1 is set at a predetermined height from the base material.

[0021] Grinding tool 120 is a device that is installed at the tip of the arm of robot 110 and grinds the weld bead by the movement of robot 110. Grinding tool 120 includes, for example, a spindle motor 121, a rotating shaft 122, and a grinding unit 123. Grinding tool 120 rotates rotating shaft 122 by spindle motor 121, thereby rotating grinding unit 123 that is installed at one end of rotating shaft 122.

[0022] The grinding part 123 is rotatably supported by the rotary shaft 122 and is, for example, a grindstone having a disk shape.

[0023] Grinding tool 120 can change the rotation speed when grinding part 123 is pressed against the weld bead based on a control signal obtained from control device 130, for example, so that grinding part 123 can grind the weld bead.

[0024] The control device 130 is a device that controls the robot 110 based on grinding conditions. For example, the control device 130 can control the robot 110 to perform a weaving motion of the grinding tool 120 against the weld bead.

[0025] This allows the control device 130 to perform grinding by reducing the inclination of the circular main surface of the grinding portion 123 of the grinding tool 120 with respect to the weld bead YB shown in Fig. 1, for example. Therefore, in the grinding system 10, wear can be made uniform on the main surface of the grinding portion 123 of the grinding tool 120, resulting in a cost reduction effect.

[0026] The control device 130 that enables the robot 110 to perform a weaving motion will be described in detail below.

[0027] ===Control device 130=== <<Configuration>> As shown in FIG. 1, the control device 130 includes a storage unit 131, a route identification unit 132, a display processing unit 133, and a control unit 134.

[0028] The storage unit 131 includes grinding condition information D131a.

[0029] The grinding condition information D131a will be described with reference to Fig. 2. Fig. 2 is a diagram showing the grinding condition information D131a. The grinding condition information D131a is a database that stores grinding conditions for the robot 110 related to the weaving operation set by the user.

[0030] As shown in FIG. 2, the grinding condition information D131a stores, for example, an [Operation Pattern] field for the weaving operation pattern, a [Frequency] field for the weaving frequency, an [Amplitude] field for the weaving amplitude, a [Stop Time] field for the stop time of the grinding unit 123, a [Progress] field for the progress during the stop time of the grinding unit 123, a [Phase] field for the phase at the start, a [Tilt Angle] field for the inclination angle of the grinding unit 123, a [Fore-aft Angle] field for the forward-backward angle of the grinding unit 123, and a [Depth Ratio] field for the roundness rate, using the weaving ID as a primary key. The various fields will be described later. That is, the control device 130 may be configured to allow the user to select and set grinding conditions previously set by the user. This improves the user's operability of the grinding system 100.

[0031] The path specifying unit 132 specifies a taught path CS1 based on the teaching of the robot 110. For example, the path specifying unit 132 may specify a taught path CS1 when grinding two weld beads by a weaving operation. In this case, the path specifying unit 132 specifies the taught path CS1 between the two weld beads, for example, as shown in FIG.

[0032] The display processing unit 133 generates various screens. Specifically, the display processing unit 133 generates a grinding condition setting screen T10. The grinding condition setting screen T10 will be described with reference to FIGS. 3, 4, and 5. FIG. 3 is a diagram showing an example of the grinding condition setting screen T10. FIG. 4 is a diagram showing an example of the trajectory of the grinding tool 120 during a weaving operation. FIG. 5 is a diagram showing an example of the trajectory of the grinding tool 120 that changes depending on the setting conditions of the weaving operation.

[0033] The grinding condition setting screen T10 is a screen that accepts user operation input and is a screen for setting grinding conditions based on the user operation input. As shown in Fig. 3, the grinding condition setting screen T10 includes, for example, a weaving operation pattern input area T11, a weaving frequency input area T12, a weaving amplitude input area T13, a stop time input area T14, a progress input area T15 during the stop time, a phase input area T16 at the start, an inclination angle input area T17, a roundness input area T18, and a grinding operation image display area T19.

[0034] The weaving motion pattern input area T11 is an area where a weaving motion pattern is input. Specifically, the weaving motion pattern input area T11 is input by the user's selection of, for example, a "linear function" which is a linear weaving motion locus CS2 shown in Fig. 4(A) in a direction intersecting the taught path CS1 as a reference, a "trigonometric function" which is a semicircular weaving motion locus CS2 shown in Fig. 4(B), or an "arc" which is a weaving motion locus CS2 that draws an approximately circle as shown in Fig. 4(C).

[0035] The weaving frequency input area T12 is an area where the number of reciprocations per unit time in various weaving operation patterns is input.

[0036] The weaving amplitude input area T13 is an area where the distance in the intersecting direction from the taught path CS1 in various weaving motion patterns is input. Specifically, in the case of a linear function weaving motion, the input distance is the length of the perpendicular line from the vertex of the triangle shown in FIG. 5A to the taught path (the "first distance" and "second distance" in FIG. 5A). In the case of a trigonometric function and arc weaving motion, the input distance is the length of the perpendicular line from the pole of the arc shown in FIG. 5C to the taught path (the "first distance" and "second distance" in FIG. 5C). This allows the grinding system 100 to adjust the reciprocating range of the weaving motion, enabling efficient grinding according to the shape of the weld bead.

[0037] The weaving amplitude input range T13 is also set so that the distance can be set on both the left and right sides of the taught path. That is, a wider range is ground on one side of the taught path, and a narrower range is ground on the other side of the taught path. This allows the grinding system 100 to adjust the left and right reciprocating range of the weaving operation to be unbalanced, enabling efficient grinding according to the shape of the weld bead.

[0038] The stop time input field T14 is a field for inputting the stop time at which the arm movement of the robot 110 is stopped during various weaving operations. The stop time input field T14 can be used to arbitrarily set a stop point in one cycle of the weaving operation. For example, the stop time input field T14 may include an input field T14a for the stop location and an input field T14b for the stop time. This enables efficient grinding according to the shape of the weld bead.

[0039] The stop time progress input field T15 is a field for selecting whether or not to continue operation in the direction along the taught path during the stop time when a stop time is input. Specifically, when "Yes" is selected in the stop time progress input field T15, grinding is performed by moving the grinding tool 120 along the taught path during the stop time, as shown in "Stop time" in Figure 5(B). This enables efficient grinding according to the shape of the weld bead.

[0040] The start phase input area T16 is an area for specifying the direction from which grinding should start along the taught path intersecting direction. Specifically, selecting "left" in the start phase input area T16 starts grinding toward the left side of the moving direction of the grinding tool 120 along the taught path, as shown in Figures 4(A) to 4(C), for example. This enables efficient grinding according to the shape of the weld bead.

[0041] The inclination angle input field T17 is a field for specifying the inclination angle of the main surface of the grinding portion 123 relative to the horizontal.

[0042] The circularity input area T18 is an area to be input when an "arc" is input in the weaving operation pattern input area T11, and is an area to input the circularity of the latter half of one cycle.

[0043] Here, the arc in the weaving operation is a trajectory formed, for example, in one cycle of the weaving operation, by a first arc C1 formed on one side of the intersecting direction of the taught path in a first direction, and a second arc C2 formed on the other side of the intersecting direction of the taught path, continuous with the first arc, in a second direction opposite to the first direction, as shown in Figure 5(C).

[0044] The circularity refers to the degree of distortion of the directional component of the taught path relative to a circular arc, which is a semicircle of a correct circle. Specifically, as shown in FIG. 5C, the circularity is the ratio of the second width W2 between two intersecting points of the taught path on the second arc C2 to the first width W1 between two intersecting points of the taught path on the first arc C1 (e.g., 80% in FIG. 5C). That is, when the circularity is set to less than 100%, the robot 110 performs a weaving operation on the grinding tool 120 so that the first width W1 of the first arc C1 is longer than the second width W2 of the second arc C2. This allows the grinding system 100 to perform multiple grinding operations on any given location of the weld bead. This reduces the inclination of the grinding part 123, enabling more efficient grinding according to the shape of the weld bead while reducing wear on the grinding part 123.

[0045] Grinding operation image display area T19 is a display area that displays an image of the weaving operation under the set grinding conditions. Grinding operation image display area T19 may display only the trajectory of grinding part 123 during the weaving operation, or may display the trajectory of grinding part 123 during the weaving operation superimposed on an image of the weld bead. This allows grinding system 100 to allow the user to easily visually understand what kind of operation will be performed on weld bead YB under the set grinding conditions.

[0046] In this way, the grinding system 100 allows the user to easily set information about the weaving operation on the grinding condition setting screen T10, thereby reducing the user's operation time required to teach the grinding operation.

[0047] The control unit 134 controls the robot 110 and the grinding tool 120 based on the grinding conditions. Here, the control unit 134 controls the robot 110 based on the grinding conditions (conditions related to the weaving operation) related to the grinding operation of the grinding tool 120 on the weld bead YB along the specified taught path CS1.

[0048] At this time, the control unit 134 may refer to the grinding condition information D131a and output a control signal for operating the robot 110 under the grinding conditions to the robot 110. Alternatively, the control unit 134 may transmit an index indicated by the grinding conditions to the robot 110, and the robot 110 may control the arm based on the index.

[0049] This enables the grinding system 100 to efficiently grind the weld bead in a single grinding operation, for example, when the weld bead YB is wide or when multiple weld beads YB are arranged in parallel.

[0050] Control unit 134 may also be able to set different grinding conditions for each of a plurality of divided regions corresponding to weld bead YB. Specifically, control unit 134 allows grinding conditions to be set for each region of weld bead YB in grinding condition information D131a. In this case, display processing unit 133 displays an input area on grinding condition setting screen T10 where grinding conditions can be set to correspond to each region of weld bead YB. This allows grinding system 100 to perform efficient grinding based on the grinding conditions at appropriate pinpoint locations of weld bead YB.

[0051] <<Processing Procedure>> The processing procedure of the grinding system 100 will be described with reference to Fig. 6. Fig. 6 is a flowchart showing the flow of the processing procedure of the grinding system 100.

[0052] In step S100, control device 130 receives, for example, a user's operation input for the image of weld bead YB displayed on display unit 1007, and sets a teaching path CS1 for weld bead YB.

[0053] In step S101, the control device 130 receives a user's input regarding grinding conditions, for example, on the grinding condition setting screen T10. The control device 130 stores the grinding conditions (for example, information regarding the weaving operation) in the storage unit 131.

[0054] In step S102, the control device 130 outputs a robot control signal indicating grinding conditions to the robot 110. Similarly, the control device 130 outputs a grinding tool control signal to the grinding tool 120 indicating the rotation speed of the grinding part 123, etc.

[0055] In step S103, robot 110 moves grinding portion 123 of grinding tool 120 based on the grinding conditions, for example, as shown in FIGS. 4(A) to 4(C), to grind the weld bead.

[0056] In step S104, the grinding tool 120 controls the rotation speed of the grinding part 123 based on the grinding tool control signal.

[0057] In step S105, the control device 130 outputs a robot stop signal and a grinding tool stop signal to the robot 110 and the grinding tool 120 to stop their operations.

[0058] In steps S106 and S107, the robot 110 and the grinding tool 120 stop operating.

[0059] As described above, grinding system 100 can efficiently grind weld beads by setting appropriate grinding conditions (conditions related to the weaving operation) according to weld beads of various shapes.

[0060] ===Hardware Configuration=== An example of a hardware configuration in which the robot 110, the grinding tool 120, and the control device 130 are realized by a computer will be described with reference to Fig. 7. Fig. 7 is a diagram showing an example of the hardware configuration of a computer.

[0061] As shown in FIG. 7, the computer 1000 includes a processor 1001, a memory 1002, a storage device 1003, an input I / F unit 1004, a data I / F unit 1005, a communication I / F unit 1006, and a display unit 1007.

[0062] The processor 1001 is a control unit that controls various processes in the computer 1000 by executing programs stored in the memory 1002 .

[0063] The memory 1002 is a storage medium such as a RAM (Random Access Memory), etc. The memory 1002 temporarily stores the program code of the program executed by the processor 1001 and data required when the program is executed.

[0064] The storage device 1003 is a non-volatile storage medium such as a hard disk drive (HDD), flash memory, etc. The storage device 1003 stores an operating system and various programs for realizing the above-mentioned components.

[0065] The input I / F unit 1004 is a device for receiving input from a user. Specific examples of the input I / F unit 1004 include a keyboard, a mouse, a touch panel, various sensors, and a wearable device. The input I / F unit 1004 may be connected to the computer 1000 via an interface such as a USB (Universal Serial Bus).

[0066] The data I / F unit 1005 is a device for inputting data from outside the computer 1000. A specific example of the data I / F unit 1005 is a drive device for reading data stored in various storage media. The data I / F unit 1005 may be provided outside the computer 1000. In this case, the data I / F unit 1005 is connected to the computer 1000 via an interface such as a USB.

[0067] The communication I / F unit 1006 is a device for performing data communication via the Internet N, either wired or wirelessly, with devices external to the computer 1000. The communication I / F unit 1006 may be provided external to the computer 1000. In this case, the communication I / F unit 1006 is connected to the computer 1000 via an interface such as a USB.

[0068] The display unit 1007 is a device for displaying various types of information. Specific examples of the display unit 1007 include a liquid crystal display, an organic EL (Electro-Luminescence) display, and a display of a wearable device. The display unit 1007 may be provided outside the computer 1000. In this case, the display unit 1007 is connected to the computer 1000 via, for example, a display cable. Furthermore, when a touch panel is used as the input I / F unit 1004, the display unit 1007 can be configured as an integrated unit with the input I / F unit 1004.

[0069] ===Summary=== <1> The control device 130 of the grinding system 100 includes a path specification unit that sets a taught path CS1, which is a reference path for the grinding unit 123, to grind the weld bead YB of the base material BZ. The control unit 134 also includes a control unit 134 that controls the robot 110 on which the grinding unit 123 is installed to perform a weaving operation based on grinding conditions for a weaving operation for grinding the weld bead YB in a direction intersecting the taught path CS1, which is acquired based on a user's operation input. This allows the grinding system 100 to perform various weaving operations in the grinding process on the weld bead, thereby enabling efficient grinding of the weld bead. Furthermore, the grinding system 100 polishes a given location multiple times through the weaving operation, thereby reducing the inclination of the grinding unit 123 relative to the weld bead. Therefore, the grinding system 100 can ensure a sufficient grinding amount while achieving a flatter ground surface of the weld bead than would be the case if the inclination were greater.

[0070] <2> The control device 130 of the grinding system 100 sets a predetermined distance in the cross direction as a grinding condition based on an operational input from the user. This allows the grinding system 100 to adjust the reciprocating range of the weaving operation, enabling efficient grinding according to the shape of the weld bead.

[0071] <3> Based on user input, the control device 130 of the grinding system 100 sets the grinding conditions as a weaving operation that draws an arc in the intersecting direction and the distance from the pole of the arc to the taught path CS1. This allows the grinding system 100 to adjust the left and right imbalance in the reciprocating range of the weaving operation, enabling efficient grinding according to the shape of the weld bead.

[0072] <4> Control device 130 of grinding system 100 forms a first arc C1 along taught path CS1 in a first direction in a direction intersecting one side of taught path CS1, and forms a second arc C2 continuous with the first arc C1 in a second direction opposite the first direction in a direction intersecting the other side of taught path CS1, setting a first width W1 between two points where first arc C1 and taught path CS1 intersect to be longer than a second width W2 between two points where second arc C2 and taught path CS1 intersect. This allows grinding system 100 to perform multiple grinding operations on any location of the weld bead, thereby reducing the inclination of grinding unit 123 and enabling more efficient grinding according to the shape of the weld bead while reducing wear on grinding unit 123.

[0073] <5> Control device 130 of grinding system 100 causes grinding unit 123 to perform a weaving operation in the cross direction so that first width W1 is larger than second width W2, based on information (e.g., roundness) about first width W1 and second width W2, which are grinding conditions set based on user operation input. This allows grinding system 100 to perform multiple grinding operations on any location of the weld bead, making it possible to reduce the inclination of grinding unit 123 and reduce wear on grinding unit 123 while grinding more efficiently in accordance with the shape of the weld bead.

[0074] The embodiments described through the above embodiments of the invention can be combined, modified, or improved as appropriate depending on the application, and the present invention is not limited to the above-described embodiments. It is clear from the claims that such combinations, modifications, or improvements are also included within the technical scope of the present invention. [Explanation of symbols]

[0075] 100...grinding system, 110...robot, 120...grinding tool, 123...grinding unit, 130...control device, 131...storage unit, 132...path identification unit, 133...display processing unit, 134...control unit.

Claims

1. a path specifying unit that specifies a teaching path that is a reference path of a grinding unit so that the grinding unit grinds the weld bead of the base material; a control unit that controls a robot on which the grinding unit is installed to enable the weaving operation based on grinding conditions related to a weaving operation for grinding the weld bead in an intersecting direction intersecting the taught path with the taught path as a reference, the weaving operation being acquired based on an operation input by a user; A control device comprising:

2. the control unit sets a predetermined distance in the intersecting direction as a grinding condition based on an operation input by a user. The control device according to claim 1 .

3. the control unit sets, based on an operation input by a user, a weaving operation for drawing an arc in the intersecting direction as the grinding condition, and a distance from a pole of the arc to the taught path. The control device according to claim 2 .

4. The control unit forming a first arc in a first direction along the taught path on one side of the taught path in the intersecting direction, and forming a second arc, continuous with the first arc, in a second direction opposite to the first direction on the other side of the taught path in the intersecting direction; a first width between two points where the first arc and the teaching path intersect is set to be longer than a second width between two points where the second arc and the teaching path intersect; The control device according to claim 3 .

5. the control unit causes the grinding unit to perform a weaving operation in the intersecting direction based on information about the first width and the second width, which are the grinding conditions set based on an operation input by a user, so that the first width is larger than the second width. The control device according to claim 4.

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