Robot system and robot operation method

Abstract

To enable an operator who conducts remote control of a robot to recognize a relative position between a tool and a workpiece preferably with a simple structure.SOLUTION: A robot system 1 includes: a slave robot 3 which holds one of a polishing tool 41 and a workpiece W; a master robot 2 which controls the slave robot 3 remotely to process the workpiece W with the polishing tool 41; a laser radiator 43 which radiates linear light L spanning the polishing tool 41 and the workpiece W; a camera 42 which captures images of the polishing tool 41 and the workpiece W to which the linear light L is radiated; and a display unit 53 which displays the images captured by the camera 42.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a robot system and a robot operation method. [Background technology]

[0002] There is known a robot system in which a worker (operator) remotely controls a robot to perform a predetermined task (see, for example, Patent Document 1). In this type of robot system, a camera image of the work site may be displayed on a monitor to provide the operator with necessary visual information.

[0003] However, it is difficult to grasp the sense of distance in the depth direction from a two-dimensional monitor image, making it difficult to grasp the distance between the position of the robot's hand and the object being worked on. In particular, when the shape of the tool or workpiece is curved, including cylindrical or free-form surfaces, it is difficult to grasp the unevenness of the shape through a monitor. Therefore, it is difficult to recognize where the tool and workpiece are in contact. When machining or polishing, if the contact position between the tool and workpiece becomes unstable, there is a risk of machining an unintended position.

[0004] One possible method to provide depth information in a remote environment is to use a head mounted display (HMD) or a 3D display. However, the former places a burden on the operator when wearing the device, while the latter requires high installation costs and has video delays. Another possible method is to use a sensor to measure the relative distance between the workpiece and the tool. However, when considering application to work that uses a wide range of tools, such as buffing, a wide-ranging measurement environment that can cover the entire work area is required. Therefore, the labor hours and measurement equipment costs required for building the environment are large. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-89736 A Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in consideration of the above circumstances, and has an object to enable an operator who remotely controls a robot to preferably grasp the relative positions of a tool and a workpiece with a simple configuration. [Means for solving the problem]

[0007] The robot system according to the present invention comprises: A robot that holds one of a processing tool and a workpiece; a remote control unit that remotely controls the robot to process the workpiece with the processing tool; A light irradiation unit that irradiates linear light across both the processing tool and the workpiece; an imaging unit that images the machining tool and the workpiece irradiated with the linear light; A display unit that displays an image acquired by the imaging unit; Equipped with. Effect of the Invention

[0008] According to the present invention, it is possible to assist an operator who remotely controls a robot in grasping the relative positions of a tool and a workpiece with a simple configuration. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a robot system according to an embodiment. [Diagram 2] FIG. 2 is a block diagram showing a schematic control configuration of the robot system according to the embodiment. [Diagram 3] FIG. 2 is a diagram showing an example of the arrangement of a camera, a laser irradiator, a polishing tool, and a workpiece during polishing work. [Figure 4] 13A and 13B are diagrams showing examples of images displayed on the display unit during a grinding operation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0011] [Robot system configuration] FIG. 1 is a diagram illustrating a schematic diagram of a robot system 1 according to the present embodiment. As shown in this figure, the robot system 1 is a master-slave remote operation system equipped with a master robot 2, which is a master robot arm, and a slave robot 3, which is a slave robot arm. In the robot system 1, an operator (worker) H operates the master robot 2 at hand, and the remote slave robot 3 operates in accordance with the movement to perform a predetermined task. In this embodiment, the workpiece W held by the slave robot 3 is brought into contact with a polishing tool 41, and the workpiece W is polished. Specifically, the robot system 1 includes a master robot 2, a slave robot 3, a polishing tool 41, a camera 42, a laser irradiator 43, and a control device 5.

[0012] The master robot 2 is an example of a remote control unit according to the present invention, and is used to remotely control the slave robot 3. Although not particularly limited, the master robot 2 is a vertical articulated robot in this embodiment, and has multiple arms 22, an operation unit 23, and multiple joints 24. The multiple arms 22 are connected in series to each other with a base 21 serving as a base end, the base 21 being fixed to the environment (for example, a factory floor, etc.). The operation unit 23 is connected to the tips of the multiple arms 22 and is a portion that receives operation by the operator H. The specific shape of the operation unit 23 is not particularly limited, and may be, for example, a handle shape, a lever shape, a game controller (game pad) shape, or the like. The multiple joints 24 rotatably connect the base 21, the multiple arms 22, and the operation unit 23. Each joint 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 24, and an encoder 242 that detects the position (speed) of the motor 241 and outputs it to the control device 5 (see FIG. 2).

[0013] The slave robot 3 is, for example, a vertical articulated robot having a structure corresponding to that of the master robot 2. Specifically, the slave robot 3 has a plurality of arms 32, an end effector 33, and a plurality of joints . The multiple arms 32 are connected in series to each other with a base 31 serving as a base end that is fixed to the environment (for example, a factory floor, etc.). The end effector 33 corresponds to the operation unit 23 in the master robot 2, and is connected to the ends of the multiple arms 32. The end effector 33 in this embodiment is, for example, a gripper capable of gripping the workpiece W, but the specific configuration is not particularly limited as long as it can firmly hold the workpiece W. The end effector 33 is also provided with a force sensor (not shown). The force sensor detects the force (or torque) received by the end effector 33 via the workpiece W, and outputs the force (or torque) to the control device 5. The multiple joints 34 rotatably connect the base 31, the multiple arms 32, and the end effector 33. Each joint 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 34, and an encoder 342 that detects the position (speed) of the motor 341 and outputs it to the control device 5 (see FIG. 2).

[0014] 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 in this embodiment is, for example, a grindstone, and its rotation is controlled by the control device 5. The polishing tool 41 polishes the workpiece W by pressing the workpiece W against the polishing tool 41 while rotating.

[0015] The workpiece W, which is the object to be polished (workpiece), is a curved metal plate in this embodiment (see FIG. 4). The workpiece W is held in a predetermined state by the end effector 33 of the slave robot 3, and the surface to be processed is pressed against the polishing tool 41. The shape, material, etc. of the workpiece W are not particularly limited as long as they can be polished by the polishing tool 41.

[0016] The camera 42 is an example of a photographing unit according to the present invention, and photographs the state in which the polishing tool 41 and the workpiece W are brought into contact with or separated from each other. The photographed image is output to the control device 5 (or directly) and displayed on a display unit 53 described later. A specific photographing mode of the camera 42 will be described later.

[0017] The laser irradiator 43 is an example of a light irradiation unit according to the present invention, and irradiates a plurality of linear lights L (see FIG. 4) onto the polishing tool 41 and the workpiece W. The linear lights L are linear visible lights (laser lights). A specific light irradiation mode of the laser irradiator 43 will be described later.

[0018] 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, the camera 42, and the laser irradiator 43. Specifically, the control device 5 includes an input unit 52, a display unit 53, a storage unit 56, and a control unit 57.

[0019] The input unit 52 is an operation means by which a user performs various operations to operate 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 another display, and is disposed in a position where it is easily visible to the operator H operating the operation unit 23 of the master robot 2 during work. The display unit 53 displays images (video) captured by the camera 42 and various information based on a display signal from the control unit 57. The display unit 53 may be a touch panel that also serves as part of the input unit 52, and may output audio.

[0020] The storage unit 56 is a memory configured to include, for example, a random access memory (RAM) and a read only memory (ROM), and stores various programs and data, and also functions as a working area for the control unit 57.

[0021] The control unit 57 is configured to include, for example, a CPU (Central Processing Unit) and controls the operation of each unit of the control device 5. Specifically, the control unit 57 causes the display unit 53 to display various information based on the operation content of the input unit 52, deploys a program pre-stored in the storage unit 56, and executes various processes in cooperation with the deployed program.

[0022] [How to work with the robot system] Next, a polishing operation method in the robot system 1 will be described. Fig. 3 is a diagram showing an example of the arrangement of the camera 42, the laser irradiator 43, the polishing tool 41, and the workpiece W during polishing work, as viewed from above. Fig. 4 is a diagram showing an example of a display image on the display unit 53 during polishing work.

[0023] First, as shown in Fig. 3, before starting the operation, a camera 42 and a laser irradiator 43 are set in a predetermined state with respect to a polishing tool 41 and a workpiece W. The polishing tool 41 and the workpiece W are arranged in advance so as to face each other in a predetermined approaching and separating direction D1, for example, in a horizontal plane. The approaching and separating direction D1 is a representative direction in which the polishing tool 41 and the workpiece W mainly approach and separate during the polishing operation.

[0024] The camera 42 is installed so that the polishing tool 41 and the workpiece W are within the angle of view. However, it is sufficient that the range of the polishing tool 41 used in the task and the range of the workpiece W to be processed are within the angle of view. At this time, the camera 42 is directed toward the workpiece W from the polishing tool 41 side so as to capture an image of the processed surface S of the workpiece W. Specifically, the camera 42 is positioned so that the imaging direction D2 of the camera 42 obliquely intersects with the approaching and separating direction D1 of the polishing tool 41 and the workpiece W from the polishing tool 41 side, while the machining range of the workpiece W falls within the angle of view.

[0025] The laser irradiator 43 is installed so that the polishing tool 41 and the workpiece W are contained within an irradiation range 43R of the linear light L. Specifically, the laser irradiator 43 is installed so as to irradiate the linear light L in the following irradiation manner. The linear light L is emitted substantially horizontally along a plane including the approaching / removing direction D1, and a plurality of linear light beams are emitted arranged at predetermined intervals in the vertical direction perpendicular to the plane (see FIG. 4(a)). It is preferable that the plurality of linear light beams L are emitted over the entire use range of the polishing tool 41. The linear light L is irradiated so as to straddle (cover) both the polishing tool 41 and the workpiece W. The linear light L is irradiated from the polishing tool 41 side toward the workpiece W so that the processed surface S of the workpiece W is irradiated. The irradiation mode of the linear light L is not limited to the above, and at least one linear light L may be irradiated so as to straddle both the polishing tool 41 and the workpiece W. The relationship in position and attitude between the camera 42 and the laser irradiator 43 may be such that the linear light L irradiated to the polishing tool 41 and the workpiece W appears as a "line" on the image captured by the camera 42.

[0026] After the installation of the camera 42 and the laser irradiator 43 is completed, the robot system 1 is operated to start the work. In the robot system 1, when the operator H operates the operation unit 23 of the master robot 2 to cause the master robot 2 to operate, 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 driving of each motor 341 of the corresponding slave robot 3, and causes the slave robot 3 to perform an operation corresponding to the master robot 2.

[0027] The working site is photographed by a camera 42, and the video is displayed in real time (two-dimensional display) on a display unit 53. An operator H operates the operation unit 23 while checking the status of the polishing tool 41 and the workpiece W by looking at the display unit 53.

[0028] At this time, the polishing tool 41 and the workpiece W are irradiated with linear light L from the laser irradiator 43. The polishing tool 41 and the workpiece W irradiated with the linear light L are photographed by the camera 42 and displayed on the display unit 53. The linear light L is irradiated so as to extend across both the polishing tool 41 and the workpiece W. Therefore, when the polishing tool 41 and the workpiece W are separated from each other, the same linear light L is displayed with a shift on the display unit 53, as shown in Fig. 4(a). The shift in the linear light L is basically a shift in inclination and distance. On the other hand, as the polishing tool 41 and the workpiece W approach each other, the deviation of the same linear light L on the display unit 53 gradually decreases (the degree of agreement gradually increases) as shown in FIG. 4(b).

[0029] Therefore, by visually checking the deviation (degree of agreement) of the linear light L on the display unit 53, the operator H can easily grasp the distance between the polishing tool 41 and the workpiece W in the depth direction. 4(b), at the middle height on the display unit 53, the corresponding linear light Lt1 on the polishing tool 41 side and the corresponding linear light Lw1 on the workpiece W side are connected on the display unit 53, and the deviation in inclination is relatively small. In contrast, above that, the corresponding linear light Lt2 on the polishing tool 41 side and the corresponding linear light Lw2 on the workpiece W side are separated on the display unit 53, and the deviation in inclination is larger. Therefore, the polishing tool 41 and the workpiece W are close to each other at the middle position and are not yet in contact above that.

[0030] [Technical effect of the present embodiment] As described above, according to this embodiment, linear light L is irradiated onto both the polishing tool 41 and the workpiece W, and the polishing tool 41 and the workpiece W irradiated with the linear light L are photographed by the camera 42 and displayed on the display unit 53. This allows the operator H to visually check the projection state of the linear light L on the display unit 53, thereby making it easier to appropriately grasp the relative positions of the polishing tool 41 and the workpiece W. Furthermore, even if the shape of the polishing tool 41 or the workpiece W is curved, including a cylindrical shape or a free-form surface, by visually checking the degree of deformation of the linear light L, the unevenness of the shape can be appropriately grasped. Therefore, with a simple configuration in which linear light L is simply irradiated, it is possible to assist the operator H in grasping the relative positions of the polishing tool 41 and the workpiece W.

[0031] Furthermore, according to this embodiment, the polishing tool 41 and the workpiece W are irradiated with a plurality of linear light beams L having different irradiation positions. Therefore, by comparing the degrees of coincidence of different linear lights L, the difference in the relative distance according to the parts of the polishing tool 41 and the workpiece W (which part is closest to contact) can be grasped.

[0032] [others] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, in the above embodiment, the operator H can easily grasp the relative positions of the polishing tool 41 and the workpiece W by visually checking the linear light L on the display unit 53. However, instead of (or in addition to) this judgment by the operator H, the relative positions of the polishing tool 41 and the workpiece W may be determined by photographing and analyzing the images. In this case, the control unit 57 calculates the degree of coincidence between the first linear light irradiated onto the polishing tool and the corresponding second linear light irradiated onto the workpiece W, based on the image captured by the camera 42. Then, the control unit 57 calculates the distance between the polishing tool 41 and the workpiece W, based on the calculated degree of coincidence, and displays it on the display unit 53. The formula for calculating the distance from the degree of coincidence of the linear light L on the image may be obtained in advance based on actual measurement or the like.

[0033] In the above embodiment, the end effector 33 of the slave robot 3 holds the workpiece W and brings it into contact with the polishing tool 41 fixed to the environment. However, the slave robot 3 may hold either the polishing tool 41 or the workpiece W. For example, the slave robot 3 may hold the polishing tool 41 and bring it into contact with the workpiece W fixed to the environment.

[0034] Furthermore, since the linear light L is laser light, it is desirable that the irradiation range be kept to a minimum from the standpoint of safety, etc. The color of the linear light L is not particularly limited, but is preferably a color that stands out against the colors of the polishing tool 41 and the workpiece W and is easily visible on the display unit 53. Furthermore, the polishing tool 41 and the workpiece W may be photographed from a plurality of different directions by a plurality of cameras 42, and the images may be displayed individually.

[0035] In the above embodiment, the master-slave type robot system 1 is exemplified. However, the robot system according to the present invention is not limited to this, and can be widely applied to a system in which an operator remotely controls a robot using a remote control unit.

[0036] In the above embodiment, "polishing (processing)" in which a workpiece is polished by a polishing tool has been described as an example of the machining (processing work) performed by the robot system 1. However, the processing broadly includes machining that brings a workpiece and a processing tool into and out of contact with each other, and also includes, for example, "grinding (processing)". 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]

[0037] 1. Robot System 2 Master Robot (Remote Control Unit) 3 Slave Robot (Robot) 41 Polishing tools (processing tools) 42 Camera (photography section) 43 Laser irradiator (light irradiation unit) 53 Display section 57 Control Department (1st Calculation Department, 2nd Calculation Department) D1 Pick-up and drop-off direction D2 shooting direction H Operator L Line light W ワーク S Processing surface

Claims

1. A robot that holds one of a processing tool and a workpiece; a remote control unit that remotely controls the robot to process the workpiece with the processing tool; A light irradiation unit that irradiates linear light across both the processing tool and the workpiece; an imaging unit that images the machining tool and the workpiece irradiated with the linear light; A display unit that displays an image acquired by the imaging unit; A robot system comprising:

2. The light irradiation unit irradiates the machining tool and the workpiece with a plurality of linear lights having different irradiation positions. The robot system of claim 1 .

3. The plurality of linear light beams are irradiated over the entire range of use of the processing tool. The robot system according to claim 2 .

4. a first calculation unit that calculates a degree of coincidence between a first linear light irradiated onto the machining tool and a second linear light irradiated onto the workpiece based on the image acquired by the photographing unit; A second calculation unit that calculates a distance between the processing tool and the workpiece based on the degree of coincidence. The robot system of claim 1 .

5. A robot operation method for a robot system including a robot that holds one of a machining tool and a workpiece, and a remote control unit that remotely controls the robot to machine the workpiece with the machining tool, comprising: Irradiating a linear light across both the machining tool and the workpiece; Photographing the machining tool and the workpiece irradiated with the linear light; The image acquired by the photographing is displayed on a display unit. How to operate a robot.

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