Robot system, control method of robot system, and control program

Abstract

To improve operability.SOLUTION: A robot system 1 includes: a master robot 2 having an operation section 23; a slave robot 3 holding a workpiece W; and a control section 57 which controls an operation of the slave robot 3 on the basis of an operation of the master robot 2. The control section 57 can change at least one of a speed scale to be multiplied when speed is transmitted from the master robot 2 to the slave robot 3 and a force scale to be multiplied when reaction force is transmitted from the slave robot 3 to the master robot 2.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a master-slave type robot system, a control method thereof, and a control program.

Background Art

[0002] A master-slave type robot system that operates a slave robot according to the operation of a master robot is known (see, for example, Patent Document 1). In this type of robot system, for example, when performing a processing operation such as polishing, there are times when it is desired to move the slave robot quickly and largely, and times when it is desired to move it finely and delicately, and there is room for improvement in operability.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present invention has been made in view of the above circumstances, and an object thereof is to improve operability.

Means for Solving the Problems

[0005] The robot system according to the present invention includes: a master robot having an operation unit; a slave robot that holds a processing tool or a workpiece; a control unit that controls the operation of the slave robot based on the operation of the master robot, wherein the control unit can change at least one of a speed scale multiplied when transmitting speed from the master robot to the slave robot and a force scale multiplied when transmitting a reaction force from the slave robot to the master robot.

Advantages of the Invention

[0006] According to the present invention, the operability can be improved.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

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

[0009] [Configuration of Robot System] FIG. 1 is a diagram showing a robot system 1 according to the present embodiment. As shown in this figure, the robot system 1 is a master-slave type remote operation system including a master robot 2 which is a master-side robot arm and a slave robot 3 which is a slave-side robot arm. In the robot system 1, an operator (human) H operates the master robot 2 at hand, and the remote slave robot 3 follows its movement and operates, and a predetermined work is performed. In the present embodiment, the work W held by the slave robot 3 is brought into contact with the polishing tool 41, and the polishing process of the work W is performed. In addition, in the robot system 1, bilateral control is performed to feedback the force information applied when the slave robot 3 operates to the master robot 2 (operator). Specifically, the robot system 1 includes a master robot 2, a slave robot 3, a polishing tool 41, a camera 42, and a control device 5.

[0010] The master robot 2 is not particularly limited, but in this embodiment, it is a vertically articulated robot and has a plurality of arms 22, an operation unit 23, and a plurality of joint parts 24. The plurality of arms 22 are connected in series with each other, with a base 21 fixed to the environment (e.g., the floor of a factory, etc.) as the base end. The operation unit 23 is connected to the tip of the plurality of arms 22 and is a part that receives the operation of the operator H. The specific shape of the operation unit 23 is not particularly limited and may be, for example, in the shape of a handle, a lever, a game controller (game pad), etc. The plurality of joint parts 24 rotatably connect the base 21, the plurality of arms 22, and the operation unit 23. Each joint part 24 is provided with a motor 241 that drives the arm 22 (or the operation unit 23) connected to the tip side of the joint part 24, and an encoder 242 that detects the position (speed) of this motor 241 and outputs it to the control device 5 (see FIG. 2).

[0011] The slave robot 3 is, for example, a vertically articulated robot having a structure corresponding to the master robot 2. Specifically, the slave robot 3 has a plurality of arms 32, an end effector 33, and a plurality of joint parts 34. The plurality of arms 32 are connected in series with each other, with a base 31 fixed to the environment (e.g., the floor of a factory, etc.) as the base end. The end effector 33 is a part corresponding to the operation unit 23 in the master robot 2 and is connected to the tip of the plurality of arms 32. The end effector 33 of this embodiment is, for example, a gripper that can grip the workpiece W, etc., but its specific configuration is not particularly limited as long as it can firmly hold the workpiece W. The plurality of joint parts 34 rotatably connect the base 31, the plurality of arms 32, and the end effector 33. Each joint part 34 is provided with a motor 341 that drives the arm 32 (or the end effector 33) connected to the tip side of the joint part 34, and an encoder 342 that detects the position (speed) of this motor 341 and outputs it to the control device 5 (see FIG. 2).

[0012] The polishing tool 41 is an example of a processing tool according to the present invention and is fixed to the base 31 of the slave robot 3. The polishing tool 41 of the present embodiment is, for example, a grindstone and is rotationally controlled by the control device 5. The polishing tool 41 polishes the workpiece W by pressing the rotating polishing tool 41 against the workpiece W.

[0013] The workpiece W to be polished (workpiece) is a curved plate made of metal in the present embodiment. The workpiece W is gripped in a predetermined state by the end effector 33 of the slave robot 3, and the processing surface is pressed against the polishing tool 41. Note that the shape, material, etc. of the workpiece W are not particularly limited as long as they can be polished by the polishing tool 41.

[0014] The camera 42 is arranged, for example, above the polishing tool 41 and photographs the state of contact between the polishing tool 41 and the workpiece W. The photographed video is output to the control device 5 (or directly) and displayed on the display unit 53 described later.

[0015] FIG. 2 is a block diagram showing a schematic control configuration of the robot system 1. As shown in this figure, the control device 5 is a computer that controls the operations of the master robot 2, the slave robot 3, the polishing tool 41, and the camera 42. Specifically, the control device 5 includes an input unit 52, a display unit 53, a storage unit 56, and a control unit 57.

[0016] The input unit 52 is an operation means for a user to perform various operations for operating the control device 5, and includes, for example, a pointing device such as a mouse and a keyboard. The display unit 53 is, for example, a liquid crystal display, an organic electroluminescence display, or other display, and is arranged at a position where the operator H who operates the operation unit 23 of the master robot 2 can easily view it during work. The display unit 53 displays the video captured by the camera 42 and various information based on the display signal from the control unit 57. Note that the display unit 53 may be a touch panel that also serves as a part of the input unit 52, or may perform audio output.

[0017] The storage unit 56 is a memory configured to include, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), etc., stores various programs and data, and also functions as a working area for the control unit 57. The storage unit 56 of the present embodiment stores in advance a scale setting program 561 for executing a scale setting process (see FIG. 3) described later and a scale adjustment program 562 for executing a scale adjustment process (see FIG. 5) described later.

[0018] In addition, the storage unit 56 stores shape data 563 and scale data 564. The shape data 563 is shape information of the polishing tool 41 and the workpiece W, and is, for example, data of the design drawings of the polishing tool 41 and the workpiece W. The shape data 563 is acquired in advance and stored in the storage unit 56.

[0019] The scale data 564 is setting information of the conversion magnification of the speed and force respectively transmitted between the master and slave (between the master robot 2 and the slave robot 3). More specifically, the speed magnification (speed scale) is a numerical value multiplied when inputting speed information from the master robot 2 to the slave robot 3. The force magnification (force scale) is a numerical value multiplied when feedbacking force (reaction force) information from the slave robot 3 to the master robot 2. In the scale data 564, each of the speed scale and the force scale is associated with the position on the surface of the workpiece W. The scale data 564 is created by the scale setting process described later and stored in the storage unit 56. Note that the scale data 564 may include information on at least one of the speed scale and the force scale.

[0020] The control unit 57 is configured to include, for example, a CPU (Central Processing Unit) and controls the operations of each part of the control device 5. Specifically, based on the operation content of the input unit 52, the control unit 57 causes the display unit 53 to display various information, expands a program stored in advance in the storage unit 56, and executes various processes in cooperation with the expanded program.

[0021] [Scale setting before processing] Subsequently, a scale setting process for creating the scale data 564 in advance prior to actual processing will be described. FIG. 3 is a flowchart showing the procedure of the scale setting process, and FIG. 4 is a diagram for explaining the content of the scale setting process.

[0022] The scale setting process is a process of creating the scale data 564 by assigning information on the speed scale and the force scale to each position (or region) of the workpiece W. This scale setting process is executed, for example, by the control unit 57 of the control device 5 reading and expanding the corresponding program from the storage unit 56 based on a user operation.

[0023] As shown in FIG. 3, when the scale setting process is executed, first, the control unit 57 reads the shape data 563 from the storage unit 56 and acquires the shape information of the polishing tool 41 (step S1). Similarly, the control unit 57 reads the shape data 563 from the storage unit 56 and acquires the shape information of the workpiece W (step S2).

[0024] Next, the control unit 57 obtains the shape (surface shape) of the contact position of the workpiece W when it comes into contact with the polishing tool 41 based on the relative position and relative posture of the polishing tool 41 and the workpiece W during processing (step S3). Here, first, the control unit 57 obtains the relative position and relative attitude of the polishing tool 41 and the work W during processing based on the shape data of the polishing tool 41 and the work W. Note that since the relative position and relative attitude of the polishing tool 41 and the work W during processing strictly depend on the operation content of the actual operator H, they are unknown at the time before processing. However, the relative position and relative attitude can be generally determined by the shape of the processing tool. In this embodiment, since the polishing tool 41 has a simple disc shape, the relative position and relative attitude with the work W during processing are almost fixed. Then, when the relative position and relative attitude of the polishing tool 41 and the work W during processing are determined, the shape of the contact position of the work W when it contacts the polishing tool 41 is obtained.

[0025] Next, the control unit 57 sets the speed scale and force scale between the master and slave based on the shape of the contact position of the work W when it contacts the polishing tool 41 (step S4). The set scale values are stored in the storage unit 56 as scale data 564 in association with the position of the work W.

[0026] Here, a specific example will be given to explain the method of setting the speed scale and force scale according to the shape of the contact position (processing position) P of the work W that contacts the polishing tool 41. For example, as shown in FIG. 4(a), when the area of the contact position P of the work W is large (the curvature is small), the operator H wants to move the work W greatly with respect to the polishing tool 41. Therefore, the speed scale is set to a large value. Also in this case, since the curvature of the contact position P is small, that is, the work W is difficult to be cut, the operator H wants to strongly press the work W against the polishing tool 41. Therefore, it is better to make it difficult for the operator H to feel the reaction force, and the force scale is set to a small value.

[0027] On the other hand, as shown in FIG. 4(b), when the area of the contact position P of the work W is small (the curvature is large), the operator H wants to move the work W slightly with respect to the polishing tool 41. Therefore, the speed scale is set to a small value. Also in this case, since the curvature of the contact position P is large, that is, the workpiece W is easily cut, the operator H wants to bring the workpiece W into weak and delicate contact with the polishing tool 41. Therefore, it is better for the operator H to easily feel the reaction force, and the force scale is set to a large value.

[0028] Next, the control unit 57 determines whether the scale value setting for the entire machining range of the workpiece W has been completed (step S5). If it is determined that the setting has not been completed (step S5; No), the process proceeds to step S3 described above. On the other hand, when it is determined that the scale setting for the entire machining range of the workpiece W has been completed (step S5; Yes), the control unit 57 terminates the scale setting process.

[0029] [Scale adjustment during machining] Subsequently, the scale adjustment process executed during machining will be described. FIG. 5 is a flowchart showing the procedure of the scale adjustment process.

[0030] The scale adjustment process is a process of adjusting the speed scale and the force scale between the master and the slave based on the machining position of the workpiece W during the polishing operation. This scale adjustment process is executed by the control unit 57 of the control device 5 reading out and expanding the scale adjustment program 562 from the storage unit 56 in accordance with the start of the polishing operation based on the user operation on the control device 5. The polishing operation is started by expanding a predetermined operation program that controls the operation of the slave robot 3 according to the operation of the master robot 2. The scale adjustment program 562 may be a part of the operation program.

[0031] As shown in FIG. 5, first, the operator H fixes the workpiece W to the slave robot 3 (step T1). At this time, the workpiece W is fixed to the slave robot 3 in a predetermined posture.

[0032] Next, the polishing operation is started, and the operator H starts operating the master robot 2 (step T2). When the operator H operates the operation unit 23 of the master robot 2 and the master robot 2 moves, the position (speed) information of each motor 241 of the master robot 2 is detected by each encoder 242. Based on the acquired position information of each motor 241 of the master robot 2, the control unit 57 controls the drive of each motor 341 of the corresponding slave robot 3, causing the slave robot 3 to perform an operation corresponding to the master robot 2.

[0033] Next, the control unit 57 obtains the machining position (contact position P) of the workpiece W at that time based on the position and posture of the polishing tool 41 and the workpiece W (step T3). Here, the control unit 57 calculates the position and posture of the workpiece W based on the position information of each motor 241 obtained from each encoder 242 of the master robot 2. The position and posture of the polishing tool 41 are fixed, and the information is input to the control device 5 in advance. Thus, the control unit 57 can obtain the relative position and relative posture between the polishing tool 41 and the workpiece W. If the relative position and relative posture between the polishing tool 41 and the workpiece W are known, the contact position P of the workpiece W that contacts the polishing tool 41 at that time, that is, the machining position, becomes clear.

[0034] Next, the control unit 57 sets (adjusts) the speed scale and the force scale based on the machining position (contact position P) of the workpiece W obtained in step T3 (step T4). Specifically, the control unit 57 reads out the speed scale and the force scale corresponding to the contact position P of the workpiece W from the scale data 564 and sets the scale values. In the present embodiment, for example, when the curvature of the contact position P of the workpiece W is small (the area is large), in order to strongly press and move the workpiece W greatly, the speed scale is set large and the force scale is set small (Fig. 4(a)). On the other hand, when the curvature of the contact position P of the workpiece W is large (the area is small), in order to gently apply and move the workpiece W finely, the speed scale is set small and the force scale is set large (Fig. 4(b)). Thereby, the operator H can suitably operate the master robot 2 with an operability corresponding to the shape of the workpiece W.

[0035] Next, the control unit 57 determines whether to end the processing (step T5). If it is determined not to end (step T5; No), the process proceeds to step T2 described above to continue the machining operation. On the other hand, for example, when the machining of the entire workpiece W is completed, or when an end operation by the operator H is input and it is determined to end the machining (step T5; Yes), the control unit 57 ends the scale adjustment process and ends the machining operation.

[0036] [Technical effects of the present embodiment] As described above, according to the present embodiment, the speed scale multiplied when transmitting the speed from the master robot 2 to the slave robot 3 and the force scale multiplied when transmitting the reaction force from the slave robot 3 to the master robot can be changed. Thereby, the operator H can operate the master robot 2 by appropriately adjusting the speed scale and the force scale. As a result, the operability can be improved.

[0037] Also, according to the present embodiment, the speed scale and the force scale are changed (set) based on the shape of the contact position P of the workpiece W that contacts the polishing tool 41. Thereby, the speed scale and the force scale corresponding to the shape of the workpiece W can be set. As a result, the master robot 2 can be preferably operated with operability corresponding to the shape of the workpiece W.

[0038] Also, according to the present embodiment, based on the respective shapes of the polishing tool 41 and the workpiece W, scale data 564 associating the contact position P of the workpiece W, the speed scale, and the force scale is created in advance. Then, based on the contact position P of the workpiece W that actually contacts the polishing tool 41 during the machining of the workpiece W, the speed scale and the force scale corresponding to the contact position P are read from the scale data 564 and set. Thereby, the scale data 564 can be preferably created only by acquiring the respective shape data of the polishing tool 41 and the workpiece W. Also, during actual machining, the speed scale and the force scale can be preferably adjusted based on the scale data 564.

[0039] [Others] As described above, the embodiments of the present invention have been explained. However, the present invention is not limited to the above embodiments. For example, in the above embodiment, the speed scale and the force scale are changed (set) based on the area and curvature of the work W. However, the shape of the contact position of the work referred to for changing the scale value is not limited to this, and may include at least one piece of information among the area, curvature, and machining cost of the work. When the machining cost is large, since it is desired to press the work strongly, it is preferable to set the force scale small and the speed scale large. When the machining cost is small, the opposite setting is preferable. Also, the operator H may be able to arbitrarily set the speed scale and the force scale.

[0040] Also, in the above embodiment, both the speed scale and the force scale are changed (set). However, it is sufficient that at least one of the speed scale and the force scale can be changed. When the force scale is not changed, the robot system 1 may not perform bilateral control. Also, when performing bilateral control, a force sensor may be mounted on the end effector 33 to detect the reaction force.

[0041] Also, in the above embodiment, the case where the polishing tool 41 is fixed and the slave robot 3 handles the work W has been exemplified. However, it is sufficient that the relative position and relative posture of the polishing tool 41 and the work W can be detected, and the slave robot 3 may hold the polishing tool 41 while fixing the work W.

[0042] Also, in the above embodiment, as the machining (processing operation) performed by the robot system, "polishing (processing)" of polishing the work with a polishing tool has been exemplified. However, the present invention can be widely applied to processing in which the work and the processing tool are brought into contact to process the work, and is applicable not only to machining such as "grinding" and "cutting", but also to "welding" and the like. In addition, the details shown in the above embodiments can be appropriately changed without departing from the gist of the invention.

Explanation of Symbols

[0043] 1 Robot system 2 Master robot 23 Operation unit 241 Motor 242 Encoder 3 Slave robot 341 Motor 442 Encoder 41 Grinding tool (processing tool) 5 Control device 56 Memory unit 57 Control unit (data creation unit) 561 Scale setting program 562 Scale adjustment program 563 Shape data 564 Scale data W Workpiece P Contact position

Claims

1. A master robot having an operation unit, A slave robot holding a processing tool or a workpiece, A control unit that controls the operation of the slave robot based on the operation of the master robot, The control unit can change at least one of a speed scale multiplied when transmitting speed from the master robot to the slave robot and a force scale multiplied when transmitting a reaction force from the slave robot to the master robot. A robot system.

2. The control unit sets at least one of the speed scale and the force scale based on the shape of the contact position of the workpiece in contact with the processing tool. The robot system according to claim 1.

3. Based on the relative position and relative attitude of the processing tool and the workpiece, obtain the shape of the contact position of the workpiece in contact with the processing tool. The robot system according to claim 2.

4. A data creation unit that creates in advance scale data associating the contact position of the workpiece with at least one of the speed scale and the force scale based on the shapes of the processing tool and the workpiece, and stores the scale data in a storage unit. The control unit reads and sets at least one of the speed scale and the force scale corresponding to the contact position from the scale data based on the contact position of the workpiece that actually contacts the processing tool during the processing of the workpiece. The robot system according to claim 2.

5. The control unit sets at least one of the speed scale and the force scale based on at least one piece of information among the area, curvature, and machining allowance of the workpiece as the shape of the contact position. The robot system according to claim 2.

6. A master robot having an operation unit, A slave robot holding a processing tool or a workpiece, A control method for a robot system including a control unit that controls the operation of the slave robot based on the operation of the master robot, The control unit changes at least one of a speed scale multiplied when transmitting speed from the master robot to the slave robot and a force scale multiplied when transmitting a reaction force from the slave robot to the master robot. A control method for a robot system.

7. A master robot having an operation unit, A slave robot that holds a processing tool or a workpiece, A control program for a robot system comprising: a control unit that controls the operation of the slave robot based on the operation of the master robot, Causing the control unit to change at least one of a speed scale multiplied when transmitting speed from the master robot to the slave robot and a force scale multiplied when transmitting a reaction force from the slave robot to the master robot, A control program for a robot system.

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