Remote Control System

Abstract

To provide a remote control system that enables a worker to work appropriately through remote control.SOLUTION: A work system 1 comprises a remote control part 31 that enables a worker to perform welding work to a work-piece by remotely controlling a torch 14, and a control device 4 that makes the remote control part 31 output force according to a position of the torch 14. The control device 4 makes the remote control part 31 output restoring force that gradually becomes larger as a tip of the torch 14 separates from a central plane to be welded.SELECTED DRAWING: Figure 4

Description

[Technical Field]

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

[0002] 2. Description of the Related Art Conventionally, remote control systems have been known in which a worker remotely controls a work robot to perform work such as welding. In the remote control system described in Patent Document 1, when the robot arm approaches an obstacle, the worker is made to perceive a reaction force, thereby avoiding a collision between the working robot and the obstacle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-11498 Summary of the Invention [Problem to be solved by the invention]

[0004] However, although the reaction force generated when a work robot approaches an obstacle is effective in avoiding collision with the obstacle, it may not function effectively in cases where, for example, it is desired to move the robot arm along a predetermined reference line, and work may not be carried out properly. The present invention has been made in view of the above circumstances, and has as its object to enable a remote operator to perform work in a suitable manner. [Means for solving the problem]

[0005] The remote control system according to the present invention comprises: a remote control means for remotely controlling the torch to perform welding work on the workpiece; a force-sense control means for outputting a force corresponding to the position of the torch to the remote control means; Equipped with The force sense control means outputs to the remote control means a first force that gradually increases as the tip of the torch moves away from a predetermined reference position. 、 The reference position is the welding center plane along the welding direction. Further, the remote control system according to the present invention comprises: a remote control means for remotely controlling the torch to perform welding work on the workpiece; a force-sense control means for outputting a force corresponding to the position of the torch to the remote control means; Equipped with the force sense control means causes the remote control means to output a first force that gradually increases as the tip of the torch moves away from a predetermined reference position; The force sense control means outputs to the remote control means, in addition to the first force, a second force that gradually increases as the tip of the torch approaches the workpiece. . [Effects of the Invention]

[0006] According to the present invention, a remote worker can perform work in an appropriate manner. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a conceptual diagram illustrating a work system according to an embodiment. [Figure 2] 1 is a perspective view of a welding vehicle according to an embodiment; [Figure 3] FIG. 2 is a view showing the periphery of the tip of the torch according to the embodiment. [Figure 4] 1 is a block diagram showing a schematic control configuration of a work system according to an embodiment; [Figure 5] 10 is a flowchart illustrating a flow of an operation assistance process according to the embodiment. [Figure 6] FIG. 10 is a diagram for explaining an operation support process according to the embodiment. [Figure 7] FIG. 10 is a diagram for explaining an operation support process according to the embodiment. [Figure 8] (a) is a calculation model of a calculation example for determining the distribution of reaction force and restoring force in the X direction, and (b) is a graph showing the calculation results, which are an example of the distribution of reaction force, restoring force, and their resultant force in the X direction. [Figure 9] 10A and 10B are diagrams for explaining modified examples of the reference position of the restoring force. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0009] [Working system configuration] FIG. 1 is a conceptual diagram showing a work system 1 according to this embodiment. As shown in this figure, the work system 1 is an example of a remote control system according to the present invention, and is configured to have a welding vehicle 10 perform welding work by remote control by a worker (operator) WK. Specifically, the work system 1 includes the welding vehicle 10, a remote control device 3, and a control device 4.

[0010] FIG. 2 is a perspective view of the welding vehicle 10. As shown in FIG. As shown in this figure, a welding vehicle 10 is a welding robot that moves in the direction of arrow α on horizontally placed iron plate materials (steel plates) 20, welding workpieces to be welded, i.e., plate materials 20 together. After welding, the plate materials 20 can be used, for example, as a floor. In the following description, the mutually orthogonal X, Y, and Z directions are set as shown in the drawings. As an example, the XY plane is horizontal, and the Z direction is vertical. The movement direction (α direction) of the welding vehicle 10 is the -Y direction. However, the movement direction of the welding vehicle 10 is not limited to the -Y direction, and may be, for example, the opposite direction (+Y direction).

[0011] The welding vehicle 10 of this embodiment performs V-groove butt welding on two plate materials 20 by arc welding. That is, two plate materials (steel plates) 20, each having an end cut at an angle to form a groove surface (side surface 20a), are butted together to form a V-groove 21 joint, and welding is performed to fill this groove (groove) 21 (see FIG. 7). A ceramic backing material 25 is disposed at the bottom of the groove 21 (not shown in FIG. 2), and the surface of the backing material 25 forms the bottom surface 25a of the groove 21. The groove 21 has a total length of 5 m or more, a width of approximately 5 mm, and a depth of approximately 10 mm, depending on the application of the plate materials 20. In this embodiment, the longitudinal direction of the groove 21 is parallel to the Y direction, the width direction of the groove 21 is parallel to the X direction, and the depth direction of the groove 21 is parallel to the Z direction. The welding vehicle 10 melts a wire (filler metal: not shown) with a torch 14 (described later) and fills the grooves 21 with the molten material, thereby welding the plate materials 20 together. In the following description, the surface of the workpiece, that is, the side surface 20a and bottom surface 25a of the groove 21 and the top surface 20b of the plate material 20 may be referred to as the "workpiece surface Sw."

[0012] Specifically, the welding vehicle 10 includes a vehicle body 11, a welding device 12, four wheels 18, and a drive unit 16 that drives each wheel 18 to rotate.

[0013] The vehicle body 11 has a rotation support portion (support portion) 13 that rotatably supports each wheel 18 (wheel body). Additionally, a drive unit 16 is fixed to the outside of each rotation support unit 13. The drive unit 16 is formed, for example, by a gear motor (geared motor), and is connected to wheels 18. The wheels 18 can be rotated by operating the drive unit 16. This rotation allows the welding vehicle 10 to travel using, for example, an upper surface 20b (front surface) of the plate material 20 as a travel surface. The number of wheels 18 arranged is four in this embodiment, but is not limited to this.

[0014] A welding device 12 is mounted on a vehicle body 11. The welding device 12 includes a torch (welding torch) 14 and a displacement mechanism 15 that supports the torch 14 so that it can be displaced. The torch 14 is a working unit that performs welding work on the plate materials 20. The torch 14 of this embodiment is configured to perform arc welding by arc discharge. This arc welding allows the plate materials 20 to be welded together easily and firmly.

[0015] The displacement mechanism 15 includes a first movement mechanism 151, a second movement mechanism 152, a third movement mechanism 153, and a rotation mechanism (angle adjustment mechanism) 154. The first moving mechanism 151 is a mechanism that moves the torch 14 relative to the vehicle body 11 in a direction parallel to the direction of the arrow α (Y direction).

[0016] A second moving mechanism 152 is connected to the first moving mechanism 151. The second moving mechanism 152 is a mechanism that moves the torch 14 relative to the vehicle body 11 in a direction (X direction) perpendicular to the direction of the arrow α. A third movement mechanism 153 is connected to the second movement mechanism 152. The third movement mechanism 153 is a mechanism that moves the torch 14 relative to the car body 11 in the vertical direction (Z direction).

[0017] A rotation mechanism 154 is connected to the third movement mechanism 153. The rotation mechanism 154 is connected to the torch 14 via a connecting portion 155. The rotation mechanism 154 is a mechanism that rotates the torch 14 around a horizontal axis relative to the vehicle body 11. The displacement mechanism 15 configured in this way makes it possible to appropriately change the position and attitude of the torch 14 relative to the joint between the plate materials 20, making it possible to easily perform welding.

[0018] FIG. 3 is a diagram showing the periphery of the tip of the torch 14. As shown in FIG. As shown in this figure, imaging unit 17 is connected to and supported by torch 14 via connecting member 171. Imaging unit 17 is composed of, for example, a CMOS camera or a CCD camera, and captures an image of the object to be photographed, including torch 14 and plate material 20 (groove 21), and acquires the image information. The acquired image information is transmitted to control device 4. In this embodiment, imaging unit 17 captures an image of the welded area around torch 14 from diagonally above in the direction of travel of welding vehicle 10 (-Y direction). The torch 14 also supports a laser light irradiation unit 19. The laser light irradiation unit 19 irradiates the plate material 20 including the grooves 21 with a laser light LB. The laser light irradiation unit 19 of this embodiment is disposed at the same position as the torch 14 in the X direction and adjacent to the torch 14 in the Y direction. This allows the laser light LB from the laser light irradiation unit 19 to be irradiated with its center at the same position as the torch 14 in the X direction. Furthermore, the laser light irradiation unit 19 of this embodiment is configured to irradiate a line laser light along the X direction as the laser light LB. This allows the imaging unit 17 to accurately detect the shape of the workpiece surface Sw.

[0019] FIG. 4 is a block diagram showing a schematic control configuration of the work system 1. As shown in FIG. As shown in this figure, the remote control device 3 is a device that allows a worker WK to remotely control the welding vehicle 10 from a separate room or the like away from the welding vehicle 10. Therefore, the work system 1 is a leader-follower system in which the welding vehicle 10 follows the operation of the worker WK without delay. The remote control device 3 has a remote control unit 31 that is held by the worker WK and can apply force in a desired direction.

[0020] By applying a force in the Y direction (or in a direction corresponding to the Y direction) to operate the remote control unit 31, the worker WK can move the torch 14 in the Y direction via the first movement mechanism 151 of the displacement mechanism 15. Similarly, the worker WK can apply force in the X direction (or in a direction corresponding to the X direction) to operate the remote control unit 31, thereby moving the torch 14 in the X direction via the second movement mechanism 152 of the displacement mechanism 15. In addition, the worker WK can apply force in the Z direction (or in a direction corresponding to the Z direction) to operate the remote control unit 31, thereby moving the torch 14 in the Z direction via the third movement mechanism 153 of the displacement mechanism 15. The remote control unit 31 can operate the displacement mechanism 15 to remotely move the torch 14 in the X, Y, and Z directions. As will be described later, the remote control unit 31 is a force feedback device that provides feedback of a reaction force according to the distance between the torch 14 and the workpiece. The form of the remote control unit 31 is not particularly limited, and a joystick or the like can be used, for example.

[0021] The control device 4 is configured, for example, by a personal computer. The control device 4 is electrically connected to the welding vehicle 10, the remote control device 3, and the welding vehicle 10, and comprehensively controls the operation of each part of the work system 1. The control device 4 is also an example of a force sense control means according to the present invention, and outputs a force corresponding to the position of the torch 14 to the remote control unit 31. Note that the "electrical connection" may be either a wireless connection or a wired connection. Specifically, the control device 4 includes a CPU 41, a storage unit 42, a communication unit 43, an input unit 44, a display unit 45, and an audio output unit 46.

[0022] The CPU 41 operates each part of the control device 4 based on the operation content of the input unit 44, deploys a program pre-stored in the memory unit 42, and works in conjunction with the deployed program to execute various processes. The storage unit 42 is a memory configured by a RAM (Random Access Memory), a ROM (Read Only Memory), etc., and stores various programs and data, and also functions as a work area for the CPU 41.

[0023] Communication unit 43 is a communication device capable of transmitting and receiving various information between remote control device 3 and welding vehicle 10. Specifically, communication unit 43 receives input signals, i.e., commands, from remote control device 3 and transmits the input signals to communication unit 101 of welding vehicle 10. The input unit 44 is an operation means by which the worker WK performs various operations to operate the control device 4, and includes, for example, a pointing device such as a mouse and a keyboard.

[0024] The display unit 45 is configured with, for example, a liquid crystal display, an organic EL display, or other display, and displays various information based on a display signal from the CPU 41. The display unit 45 of this embodiment displays images captured by the imaging unit 17, etc. The worker WK can perform remote control while visually checking the images displayed on the display unit 45. The display unit 45 may be a touch panel that also serves as part of the input unit 44. The audio output unit 46 is configured by, for example, a speaker, and outputs various sounds based on audio output signals from the CPU 41.

[0025] In addition to the above configuration, welding vehicle 10 has a communication unit 101 and a control unit 102. The communication unit 101 is a communication device capable of transmitting and receiving various types of information to and from the communication unit 43 of the control device 4. Specifically, the communication unit 101 receives an input signal from the remote control device 3 transmitted from the communication unit 43 of the control device 4, and transmits image information acquired by the imaging unit 17 to the communication unit 43 of the control device 4. Control unit 102 controls the operation of each unit of welding vehicle 10 based on the input signal received by communication unit 101 from remote control device 3. In this way, welding vehicle 10 is remotely controlled in accordance with the input signal.

[0026] [Operation support processing] Next, the operation support process executed during welding work by the work system 1 will be described. FIG. 5 is a flowchart showing the flow of the operation support process, and FIGS. 6 and 7 are diagrams for explaining the operation support process. The operation support process is a process that assists the worker WK in remotely operating the welding vehicle 10 by promoting understanding of the work situation by the worker WK during welding work performed by the worker WK by remotely operating the welding vehicle 10. This operation support process is executed by the CPU 41 of the control device 4 reading and developing a corresponding program from the storage unit 42 based on, for example, an input operation by the worker WK.

[0027] As shown in FIG. 5, when the operation support process is executed, first, the CPU 41 of the control device 4 starts the operation of groove welding the workpiece by remote control by the worker WK (step S1). In this welding operation, CPU 41 transmits an input signal corresponding to the operation of remote control unit 31 by worker WK to welding vehicle 10. Control unit 102 of welding vehicle 10 operates each unit based on the received input signal. As a result, welding vehicle 10 moves along groove 21 while supplying wire downward from the tip (lower end) of torch 14 and melting the wire to weld plate materials 20 together. At this time, CPU 41 also causes display unit 45 to display in real time an image of the welded area around torch 14 captured by imaging unit 17 of welding vehicle 10. This captured image (video) of the welded area includes the wire supplied from the tip of torch 14, the workpiece (groove 21), the arc generated between them, and the molten pool (front molten pool) where the wire is melted by the arc. Worker WK operates remote control unit 31 while visually checking the captured image displayed on display unit 45 to confirm the welding situation and state. In this specification, unless otherwise specified, the term "torch 14" includes the wire fed from its tip. In other words, the "tip of torch 14" refers to the tip of the wire when the wire is being fed, and the "collision between torch 14 and workpiece" includes the collision between the wire and workpiece.

[0028] Next, the CPU 41 calculates a reaction force Fb that gradually increases as the tip of the torch 14 approaches the workpiece, and outputs the reaction force Fb to the remote control unit 31 (step S2). The reaction force Fb is an example of a second force according to the present invention. Specifically, as shown in FIG. 6, a region of interest (ROI) centered on the point closest to the tip of the torch 14 is extracted from the point cloud data, and the reaction force Fb is calculated as a weighted sum of vectors pointing from each point to the tip of the torch 14. Point cloud data of the workpiece surface Sw is acquired as needed by the laser beam irradiation unit 19. However, point cloud data acquired in advance using the laser beam irradiation unit 19 (or a CAD model of the workpiece) may also be used. The ROI is formed into a square shape by extracting a predetermined number of points in each of the X and Y directions, with the point closest to the tip of the torch 14 as its center. Each point in the ROI exerts a force on the tip of the torch 14 whose magnitude is inversely proportional to the distance from the point to the tip of the torch 14, and the reaction force Fb is calculated as the resultant force using the following equation (1).

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[0029] In this way, the reaction force Fb output from the remote control unit 31 is inversely proportional to the distance between the tip of the torch 14 and the workpiece surface Sw. Therefore, the worker WK operating the remote control unit 31 feels a stronger reaction force Fb as the tip of the torch 14 approaches the workpiece. In other words, the worker WK can sense the distance between the torch 14 and the workpiece from the reaction force Fb fed back to the remote control unit 31. The torch 14 will not get closer to the workpiece surface Sw than the collision avoidance surface Sc, which is a predetermined distance from the workpiece surface Sw (see FIG. 7(b)). This allows the worker WK to recognize the approach of the torch 14 to the workpiece surface Sw, and makes it possible to effectively prevent a collision between the torch 14 and the workpiece.

[0030] 5, the CPU 41 calculates a restoring force Fc that gradually increases as the tip of the torch 14 moves away from the welding center plane C, and outputs the calculated force to the remote control unit 31 (step S3). Here, the welding center plane C is a reference plane along the welding direction (Y direction), as shown in FIGS. 7(a) and 7(b), that passes through the center of the groove 21 in the width direction (groove center) and is parallel to the YZ plane. The restoring force Fc is an example of a first force according to the present invention. Specifically, the CPU 41 calculates the restoring force Fc using the following equation (2).

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[0031] In this way, the restoring force Fc output from the remote control unit 31 is proportional to the distance between the tip of the torch 14 and the welding center plane C. Therefore, the worker WK operating the remote control unit 31 feels a stronger restoring force Fc as the tip of the torch 14 moves away from the welding center plane C. In other words, the worker WK can sense the distance between the torch 14 and the welding center plane C from the restoring force Fc fed back to the remote control unit 31. This allows the torch 14 to be held appropriately near the welding center plane C.

[0032] Here, an example of calculation is shown in which the distribution of each of the reaction force Fb and the restoring force Fc in the X direction (the width direction of the groove 21) is obtained. 8(a) is a diagram showing the calculation model. As shown in this figure, in this calculation, a simplified model was used in which the tapered side surface 20a was assumed to be a surface perpendicular to the X direction (indicated by the two-dot chain line in the figure), and both the reaction force Fb and the restoring force Fc were assumed to depend only on the position of the tip of the torch 14 in the X direction.

[0033] FIG. 8(b) is a graph showing the calculation results, which shows an example of the distribution of the reaction force Fb, the restoring force Fc, and the resultant force F of these in the X direction. As shown in this figure, the reaction force Fb remains small until the torch 14 approaches the side surface 20a of the groove 21, and then suddenly increases when it approaches the side surface 20a. Therefore, although this is effective in preventing the torch 14 from colliding with the side surface 20a, it is not very effective in keeping the torch 14 near the welding center plane C (X=0). In this regard, the restoring force Fc increases in proportion to the distance between the tip of the torch 14 and the welding center plane C, and therefore functions effectively to hold the torch 14 in the vicinity of the welding center plane C. Therefore, by making the worker WK perceive the resultant force F of the reaction force Fb from the work surface Sw (side surface 20a) and the restoring force Fc toward the welding center plane C, the worker WK can hold the torch 14 near the welding center plane C while avoiding collision between the torch 14 and the work.

[0034] Next, as shown in FIG. 5, the CPU 41 determines whether or not to terminate the operation support process (step S4), and if it determines not to terminate the process (step S4; No), the CPU 41 shifts the process to the above-mentioned step S1 and continues the welding work. Then, when it is determined that the operation support process should be ended due to, for example, the end of welding work (step S4; Yes), the CPU 41 ends the operation support process.

[0035] [Technical effect of this embodiment] As described above, according to this embodiment, the restoring force Fc that gradually increases as the tip of the torch 14 moves away from the welding center plane C (groove center) is output to the remote control unit 31. As a result, the worker WK operating the remote control unit 31 can perceive the restoring force Fc and hold the torch 14 near the welding center plane C. Therefore, the worker WK can move the torch 14 in a desired trajectory and perform welding work appropriately. This not only improves welding quality, but can also be effectively used as a training tool for acquiring welding skills.

[0036] Furthermore, according to this embodiment, in addition to the restoring force Fc, a reaction force Fb that gradually increases as the tip of the torch 14 approaches the workpiece is output to the remote control unit 31. The reaction force Fb effectively prevents the torch 14 from colliding with the workpiece. Therefore, by perceiving the resultant force F of the restoring force Fc and the reaction force Fb, the worker WK can hold the torch 14 near the welding center plane C while avoiding collision between the torch 14 and the workpiece.

[0037] [others] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. For example, the restoring force Fc may be any force that gradually increases as the tip of the torch 14 moves away from a predetermined reference position, and this reference position is not limited to the welding center plane C. In addition, it is preferable that this reference position be configured to be changeable. Specifically, the reference position does not have to be the center of the groove, but may be a position shifted to the left or right (in the X direction) from the center of the groove. Alternatively, as shown in Fig. 9, the reference position (reference line) C1 may be set by swinging the torch 14 left or right relative to the welding direction. This allows for optimal weaving welding. Furthermore, the reference position may be a line rather than a plane as in the above embodiment. For example, if the reference position is a line along the Y direction, the Z direction position as well as the X direction position become parameters of the restoring force Fc.

[0038] It is also preferable that the outputs of the reaction force Fb and the restoring force Fc can be individually set to be switched on or off based on a user operation, etc. It is also preferable that the magnitudes of the outputs of the reaction force Fb and the restoring force Fc can be individually changed or adjusted based on a user operation, etc.

[0039] In the above embodiment, the operation target of the remote control device 3 is the welding vehicle 10, but the operation target of the remote control means according to the present invention is not particularly limited as long as it has a working unit that performs work on a workpiece. For example, it may be a stationary robot arm, or a linear slider or actuator. Furthermore, the remote control device 3 and the control device 4 may be configured integrally (for example, as an integrated remote control device).

[0040] In the above embodiment, welding work is performed by the working system 1. However, the work (type) according to the present invention is not limited to welding, and may be any work that can be performed on a workpiece by remotely operating a working unit, including, for example, surface processing work such as polishing and painting. In addition, the details shown in the above embodiment can be modified as appropriate without departing from the spirit of the invention. [Explanation of symbols]

[0041] 1. Work system (remote control system) 3 Remote control device 4. Control device (force sense control means) 10 Welding Vehicle 14 Torch 20 Board material 20a Side 20b Top surface 21 Groove 25a Bottom 31 Remote control unit (remote control means) 41 CPU C Welding center plane (reference position) C1 Reference position (reference line) Fb reaction force Fc restoring force F resultant force Sc collision avoidance surface Sw Work surface WK Worker

Claims

1. a remote control means for remotely controlling the torch to perform welding work on the workpiece; a force-sense control means for outputting a force corresponding to the position of the torch to the remote control means; Equipped with the force sense control means causes the remote control means to output a first force that gradually increases as the tip of the torch moves away from a predetermined reference position; The reference position is a welding center plane along the welding direction. Remote control system.

2. A remote control means for remotely controlling the torch to perform welding work on a workpiece; a force-sense control means for outputting a force corresponding to the position of the torch to the remote control means; Equipped with the force sense control means causes the remote control means to output a first force that gradually increases as the tip of the torch moves away from a predetermined reference position; the force sense control means causes the remote control means to output, in addition to the first force, a second force that gradually increases as the tip of the torch approaches the workpiece; Remote control system.

3. the force sense control means causes the remote control means to output, in addition to the first force, a second force that gradually increases as the tip of the torch approaches the workpiece; The remote control system according to claim 1 .

4. the force sense control means is capable of individually setting on / off switching of the output of the first force and the output of the second force; The remote control system according to claim 2 or 3.

5. the force sense control means is capable of individually changing the magnitudes of the first force and the second force; The remote control system according to any one of claims 2 to 4.

6. The force sense control means is configured to be able to change the reference position. The remote control system according to any one of claims 1 to 5.

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