WO2024190300A1

WO2024190300A1 - Workpiece attachment/detachment system

Info

Publication number: WO2024190300A1
Application number: PCT/JP2024/005778
Authority: WO
Inventors: 直純谷川
Original assignee: 株式会社牧野フライス製作所
Priority date: 2023-03-15
Filing date: 2024-02-19
Publication date: 2024-09-19
Also published as: JP2024131075A; JP7493643B1

Abstract

A workpiece attachment/detachment system (10) for attaching/detaching a workpiece (W) for processing comprises a workpiece attachment platform (16), a station (14, 15) including a clamper (74) for actuating a movable member (78) to mount/remove the workpiece (W) onto/from the workpiece attachment platform (16) and a fixed member (84) fixed in the vicinity of the clamper (74), a robot (30) having a camera (46) and a robot hand (42) capable of gripping the workpiece (W), an unmanned conveying vehicle (32) on which the robot (30) is placed and which is capable of moving in order to move to an imaging position, and a robot control device (31) and a higher-level control system (48) for determining an attachment/detachment state of the workpiece (W) with respect to the workpiece attachment platform (16) on the basis of an image captured by the camera (46), characterized in that the camera (46) simultaneously images the movable member (78) and the fixed member (84).

Description

Workpiece attachment/detachment system

The present invention relates to a workpiece attachment/detachment system.

Patent Document 1 discloses a processing system that uses a robot to attach and detach a workpiece to and from a machine tool. This allows the workpiece to be attached and detached in a short time. This processing system is configured to detect the position of the workpiece from the rotation angle of the drive motor of the holding member and the robot arm, and to correct any misalignment. For this reason, in order to control the position of the workpiece, it is necessary to position the robot in a fixed position.

However, if a robot is placed in a fixed position, and there are multiple machine tools installed in a manufacturing area, one robot is required for each machine tool. A robot placed in this way is stopped while the machine tools are processing. Furthermore, since the robot is placed adjacent to the machine tools, pallets for mounting workpieces cannot be loaded and unloaded from the side where the robot is installed, and a separate loading/unloading entrance must be provided on the side where the robot is not installed. Also, when the pallet and hydraulic/pneumatic supply device are disconnected when a workpiece is attached or detached, it is not easy to check the hydraulic/pneumatic pressure, so even if a pressure drop occurs, it cannot be immediately detected. For this reason, there is room for improvement in efficiently attaching and detaching workpieces using a robot.

Patent No. 6626165

In consideration of the above circumstances, the present invention aims to provide a workpiece attachment/detachment system that can efficiently attach and detach workpieces using a robot.

According to one aspect of the present invention, a workpiece mounting/removal system for mounting/removing a workpiece for machining includes a workpiece mounting table for mounting the workpiece, a workpiece mounting device having a clamper for mounting or removing the workpiece from the workpiece mounting table by operating a movable member and a fixed member fixed near the clamper, a robot having a hand configured to grasp the workpiece and a camera configured to photograph the movable member and the fixed member at a photographing position, a moving body on which the robot is placed and which can move in any direction to move the robot to the photographing position, and a control device for operating the clamper, robot, and camera, which determines the mounting/removal state of the workpiece on the workpiece mounting table based on an image captured by the camera, and the camera is characterized in that it photographs the movable member and the fixed member simultaneously.

In addition, according to one aspect of the present invention, a first image capturing unit may be formed on a movable member and the orientation of which changes when the movable member is actuated, and a second image capturing unit may be formed on a fixed member, and the first image capturing unit and the second image capturing unit may face the camera in the same direction, and the camera may capture images of the first image capturing unit and the second image capturing unit simultaneously.

Furthermore, according to one aspect of the present invention, the control device may be configured to determine whether the clamper is in a clamped state in which the workpiece is attached to the workpiece mounting table, or in an unclamped state in which the workpiece is removed from the workpiece mounting table, based on the relative positions of the first and second photographing units in an image captured by the camera, and to operate a cleaning means to clean the area around the clamper and the workpiece if it determines that the movable member has deviated from the reference position in the clamped or unclamped state by more than a threshold value.

Furthermore, according to one aspect of the present invention, the work mounting table may be equipped with a pressure gauge for displaying the pressure supplied to the clamper using the hydraulic/pneumatic pressure supply device, and the control device may be configured to detect the pressure value of the clamper from an image of the pressure gauge captured by the camera, and remove the work from the work mounting table if the pressure value is below a threshold value.

In the workpiece mounting/removal system according to one aspect of the present invention, the robot has a hand configured to be able to grasp the workpiece, and can be moved by a moving body that can move in any direction. Therefore, the control device can move the robot to the workpiece mounting device by operating the moving body on which the robot is placed, and can place the workpiece on the workpiece mounting table by operating the hand of the robot. This allows the robot to be moved appropriately to the workpiece mounting device that requires the workpiece to be mounted/removed, rather than disposing the robot for each workpiece mounting device, and can efficiently mount and remove the workpiece using the robot. Furthermore, the robot has a camera configured to be able to photograph the movable member and the fixed member at the shooting position, and can be moved to the shooting position by the moving body. Therefore, the control device can move the robot to the shooting position by operating the moving body on which the robot is placed, and can simultaneously photograph the movable member and the fixed member by operating the camera. The control device can determine the mounting/removal state of the workpiece on the workpiece mounting table based on the image taken by the camera. Therefore, for example, when it is determined that the workpiece is properly mounted on the workpiece mounting table, processing can be continued. Furthermore, if it is determined that the workpiece is not properly attached to the workpiece mounting table, the control device can include, for example, a process of operating the clamper and robot to remove the workpiece and then reattach it, or a process of interrupting processing to improve the attachment. This allows the process of checking for and resolving any malfunctions in the workpiece mounting device to be included, allowing the robot to efficiently mount and remove the workpiece.

FIG. 1 is a perspective view of a workpiece mounting/removing system according to this embodiment, seen from above. FIG. 2 shows a plan view of the workpiece mounting and dismounting system according to this embodiment. FIG. 3 shows an example of the floor layout of a manufacturing area having a workpiece loading/unloading system according to this embodiment. FIG. 4 is a perspective view of the stand according to this embodiment, seen from above. FIG. 2 is a front view of the work setting station according to the embodiment, showing the door in a closed state. FIG. 2 is a front view of the work setting station according to the embodiment, showing a state in which the door is open. FIG. 2 is a perspective view of an example of a workpiece mounting table according to the present embodiment, illustrating a state in which a workpiece is clamped. FIG. 2 is a perspective view of an example of a workpiece mounting table according to the present embodiment, illustrating an unclamped state of a workpiece. 10 is an enlarged view of an example of a first photographing portion and a second photographing portion formed on the movable member and the fixed member according to the embodiment, showing a clamped state of a workpiece. FIG. 11 is an enlarged view of an example of a first photographing portion and a second photographing portion formed on the movable member and the fixed member according to the present embodiment, showing a state in which the workpiece is unclamped. FIG. FIG. 8 shows an example of a circuit diagram of the workpiece mounting device according to this embodiment. FIG. 2 is a perspective view of the pressure gauge according to the embodiment, showing a case where the pressure is equal to or greater than a threshold value. FIG. 2 is a perspective view of the pressure gauge according to the embodiment, showing a case where the pressure is equal to or lower than a threshold value. FIG. 10 shows a flowchart of the workpiece mounting and unmounting process by the workpiece mounting and unmounting system according to this embodiment. FIG. 11 is a perspective view of a workpiece mounting table according to a modified example.

The workpiece mounting/removal system 10 according to the embodiment will be described below with reference to the attached drawings. Similar or corresponding elements are given the same reference numerals, and duplicated explanations will be omitted. To facilitate understanding, the scale of the drawings may be changed for explanation.

FIG. 1 shows a perspective view of a workpiece mounting/removal system 10 arranged in a manufacturing area MA (see FIG. 3) of a factory or the like. FIG. 2 shows a plan view of the workpiece mounting/removal system 10. The workpiece mounting/removal system 10 includes workpiece setting stations 14, 15 (hereinafter referred to as station 14) as workpiece mounting devices that mount a workpiece W and supply it to

machine tools

12, 13.

Stations

14, 15 may be configured independently and connected to

machine tools

12, 13 such as machining centers, or may be configured integrally with

machine tools

12, 13. Inside

stations

14, 15, a workpiece mounting table 16 (see FIG. 6a) is arranged for mounting a workpiece W to be machined by

machine tools

12, 13.

As shown in FIG. 1, the station 14 has an entrance 18 for moving the workpiece W into the station 14, i.e., for bringing it in and out of the station 14, and a door 20 formed to be slidable for opening and closing the entrance 18. The door 20 is fitted with a door handle 20a for gripping when opening and closing. Near the door 20, a material placement table 22 for loading the unprocessed workpiece W and a work placement table 24 for loading the processed workpiece W are arranged. The material placement table 22 is formed with a temporary placement table 23 for temporarily placing the workpiece W. In addition, the material placement table 22 and the work placement table 24 each have four

legs

22a, 24a, and are configured so that the height position of the workpiece W placed on the material placement table 22 and the work placement table 24 is approximately the same as the height position of the robot hand 42 as a hand described later. This prevents the movement distance of the robot hand 42 from increasing, allowing it to operate efficiently. Additionally, an oil and air pressure supply device 26 is located adjacent to the outside of the station 14 to supply oil and air pressure to the work mounting table 16.

The workpiece attachment/detachment system 10 also includes a robot 30 for loading and unloading the workpiece W. The robot 30 loads the unprocessed workpiece W on the material placement table 22 onto the workpiece mounting table 16 in the station 14, and loads the processed workpiece W from the workpiece mounting table 16 onto the workpiece placement table 24. The robot 30 is attached to a base 34 on the upper surface of an automated guided vehicle 32 as a moving body, and is configured to be movable within the manufacturing area MA. The robot 30 further includes a cylindrical support 36 configured to be rotatable around an axis perpendicular to the base 34, here an axis along the vertical direction, and an arm unit 40, one end of which is rotatably attached to the support 36, and multiple arms 40a connected via multiple joints 38 are configured to be rotatable around the joints 38.

A robot hand 42 is detachably connected to the other end of the arm 40 of the robot 30 as a hand for gripping the workpiece W. The robot hand 42 is configured to be rotatable around the axis of the arm 40a so that the orientation can be adjusted when gripping the workpiece W. In addition, a robot hand holder 44 is attached to the base 34, and the robot hand 42 is stored in this robot hand holder 44 when not in use.

The workpiece attachment/detachment system 10 also includes a camera 46 arranged on the other end of the arm section 40, i.e., on the side of the robot hand 42. The camera 46 is arranged so as to capture an image of the side of the robot hand 42 gripping the workpiece W, and is configured to be rotatable around the axis of the arm 40a together with the robot hand 42. The camera 46 may be of any type, such as a stereo camera or a three-dimensional camera, as long as it can provide a predetermined resolution. In addition, a robot control device 31 is provided inside the base section 34 as a control device for controlling the behavior of the robot 30 and the camera 46.

As shown in FIG. 2, the workpiece attachment/detachment system 10 includes a host control system 48 as a control device for controlling the

stations

14, 15, the robot 30, and the automated guided vehicle 32 in the manufacturing area MA. The host control system 48 is connected to the

stations

14, 15, the robot 30, and the automated guided vehicle 32 wirelessly and/or by wire for communication. The automated guided vehicle 32 is operated by the host control system 48 and is configured to automatically travel to a specified destination on the floor surface FS of the manufacturing area MA without a human driver. A Mecanum wheel (not shown) is rotatably attached to the lower side of the automated guided vehicle 32. The wheel can be formed by a combination of a normal tire and a wheel, but is preferably formed by a Mecanum wheel. The Mecanum wheel can turn using the rotation difference of the wheels. In addition, by controlling the rotation difference of the wheels, it is possible to perform not only linear movement in the rotation direction of the wheel like a normal wheel, but also parallel movement in all directions and straight turns. This allows the automated guided vehicle 32 to move in multiple operating modes, including straight, lateral, diagonal, curving, turning, serpentine, and cranking.

The upper control system 48 is also electrically connected to the

machine tools

12, 13 and

stations

14, 15, and can detect whether a workpiece W is attached in station 14 and whether the machine tool 12 for machining the workpiece W is operating. For this reason, the upper control system 48 operates the robot 30 to carry an unmachined workpiece W into station 14 on one of the machine tools 12, and then operates the automated guided vehicle 32 to move the workpiece W to the other machine tool 13 side where machining is not being performed while the machine tool 12 is machining the workpiece W (T1 in FIG. 2). The upper control system 48 moves the robot 30 and the automated guided vehicle 32 to the other machine tool 13 side, and then operates the robot 30 to carry the unmachined workpiece W into the other station 15. Furthermore, when the host control system 48 detects that one of the machine tools 12 has completed machining the workpiece W, it moves the robot 30 and the automated guided vehicle 32 to the side of the one of the machine tools 12 (T2 in FIG. 2), or when the one of the machine tools 12 has not completed machining the workpiece W, it moves the robot 30 and the automated guided vehicle 32 to the side of another machine tool (see FIG. 3) to which the workpiece W is not attached (T3 in FIG. 2). In this way, the host control system 48 appropriately moves the automated guided vehicle 32 to the

machine tools

12, 13 that require work by the robot 30.

FIG. 3 shows an example of the floor layout of a manufacturing area having a workpiece attachment/detachment system 10. The upper control system 48 operates the automated guided vehicle 32 and the robot 30 in the manufacturing area MA. For this reason, the upper control system 48 operates the automated guided vehicle 32 to move it to the material stocker 54 in the manufacturing area MA, and operates the robot 30 to take out unprocessed workpieces W from the material stocker 54 and place them on the upper surface of the automated guided vehicle 32 as many as required. Furthermore, when the required number of workpieces W are placed on the automated guided vehicle 32, the upper control system 48 moves the automated guided vehicle 32 to the side of the station 14 and the material placement table 22, and operates the robot 30 to place the carried workpieces W on the material placement table 22. This allows new workpieces W to be automatically supplied to the material placement table 22 where the unprocessed workpieces W had disappeared.

The host control system 48 can also operate the robot 30 to place the machined workpiece W on the workpiece placement table 24 on the upper surface of the automated guided vehicle 32. After the workpiece W is placed on the host control system 48, it can operate the automated guided vehicle 32 to move it to a workpiece stocker 56 in the manufacturing area MA, and operate the robot 30 to store the machined workpiece W that it has brought in the workpiece stocker 56. This allows the machined workpiece W that is loaded on the workpiece placement table 24 to be automatically stored in the workpiece stocker 56.

Furthermore, if the upper control system 48 determines, for example, that the robot hand 42 attached to the robot 30 is not suitable for the size of the workpiece W, or that a different tool should be attached instead of the robot hand 42 based on the shape of the workpiece W, it can operate the automated guided vehicle 32 to move it to a hand locker 58 or tool locker 60 in the manufacturing area MA. Once the robot 30 has moved to the hand locker 58 or tool locker 60, it can attach a different robot hand 42 or tool in place of the attached robot hand 42. This makes it possible to automatically attach a robot hand 42 or tool to the robot 30 according to the size and shape of the workpiece W.

4 shows an oblique view of the material placement table 22 and the work placement table 24 seen from above. The material placement table 22 has a temporary placement table 23 on which the work W is temporarily placed. In addition, a placement table position mark 50 and a placement table information mark 52 are formed on the material placement table 22 and the work placement table 24 to serve as a reference when aligning using an image captured by the camera 46 of the robot 30. The placement table position mark 50 is a plate colored in a different color from the material placement table 22 and the work placement table 24, or a bolt of a different color screwed into them. The placement table position mark 50 and the placement table information mark 52 may be a sticker, tape, or the like that can be attached. The placement table position mark 50 displays a letter, symbol, or mark (the letter "M" in FIG. 4) that can confirm the orientation. A QR code (registered trademark) may be used as the placement table position mark. Here, a QR code (registered trademark) is used for the placement table information mark 52, and the corresponding part number, the state of the workpiece W to be loaded, and the workpiece vacancy number indicating the vacant space for the workpiece W are recorded. This allows the robot 30 and the automated guided vehicle 32 to photograph the material placement table 22 and the workpiece placement table 24 with the camera 46, align them relative to each other, and confirm the corresponding part number of the workpiece W.

FIGS. 5a and 5b show perspective views of the door 20 of the station 14 in the closed and open states, respectively. When the automated guided vehicle 32 moves to a position facing the door 20 of the station 14, i.e., in front of the door 20, it photographs the station 14 with the camera 46 of the robot 30. The robot control device 31 is configured to determine whether the robot 30 attached to the automated guided vehicle 32 is positioned in an appropriate position from the photographed image of the station 14. The robot control device 31 is also configured to determine whether the door 20 is in an open or closed state from the photographed image of the station 14.

A number of operation buttons, four in this case, are arranged along the vertical direction of the station 14 beside the door 20. Specifically, on the upper side, a lock operation button 66a for locking or unlocking the door 20, and a work clamp button 66b for clamping or unclamping the work W placed on the work mounting table 16 are arranged. Furthermore, on the lower side, a work set completion button 66c for transmitting to the machine tool 12 (see FIG. 3) that the work W has been attached to the work mounting table 16 and clamped, and a supply device button 66d for connecting or disconnecting the hydraulic and pneumatic supply device 26 for supplying hydraulic and pneumatic pressure to the work mounting table 16 are arranged. In addition, an air nozzle 68 as a cleaning means is arranged below the four

operation buttons

66a, 66b, 66c, and 66d beside the door 20. The air nozzle 68 can blow away and suck up dirt and dust around the machine by air blowing and vacuuming. It has a retractable hose (not shown) that can be pulled out by the robot hand 42 or a person. Therefore, by operating the robot hand 42 to clamp the air nozzle 68 and pull it out to the inside of the station 14, and spraying air, it is possible to clean the inside of the station 14 and the area around the workpiece W clamped to the workpiece mounting table 16.

The robot control device 31 can operate the robot hand 42 to slide open the door 20, and then use the robot hand 42 to grasp the unmachined workpiece W loaded on the material placement table 22 and move, i.e., carry, it to the workpiece mounting table 16 inside the station 14. In addition, when the moved workpiece W is attached to the workpiece mounting table 16, the robot control device 31 can operate the robot hand 42 to clamp the door handle 20a and slide the door 20 to close it.

In addition, after the door 20 is closed, the robot control device 31 can operate the robot hand 42 to press the lock operation button 66a to lock the door 20, and can also operate the robot hand 42 to press the work set completion button 66c, thereby communicating to the machine tool 12 that the setting of the workpiece W has been completed.

Figures 6a and 6b show perspective views of the workpiece mounting table 16 in a state where the workpiece W is clamped by the clamper 74 (hereafter referred to as the clamped state) and in an unclamped state (hereafter referred to as the unclamped state), respectively. The workpiece mounting table 16 is composed of a plate base 70 and an angle plate 72 that is placed on the plate base 70 and extends perpendicular to the plate base 70, in this case in the vertical direction. On the side of the angle plate 72 where the workpiece W is attached, multiple clampers 74, here four, are arranged for clamping the four corners of the workpiece W to fix it in place. The angle plate 72 also has a workpiece mounting portion 76 for stably mounting the workpiece W before clamping.

The clamper 74 has a movable member 78 that is operable by hydraulic pressure or air pressure supplied from the hydraulic/pneumatic supply device 26. The movable member 78 has a cylindrical shaft member 80 that extends in a direction perpendicular to the angle plate 72, in this case, horizontally, and a rectangular claw member 82 that is connected to the end of the shaft member 80. The shaft member 80 is configured to be slidable along its axial direction. Therefore, it can be pulled out to the outside of the angle plate 72 or pulled back to the inside depending on the thickness of the workpiece W. The shaft member 80 is also configured to be rotatable around an axis along its axial direction. One end of the claw member 82 is connected to the shaft member 80 and is configured to be rotatable in accordance with the rotation of the shaft member 80. When the shaft member 80 rotates, the claw member 82 rotates 90 degrees toward the workpiece W, and the other end of the claw member 82 is configured to engage with the workpiece W placed on the workpiece placement section 76. The angle plate 72 also has a fixed member 84 that is fixed near the clamper 74 to check the relative positional relationship with the movable member 78.

The angle plate 72 also has a nozzle connection part 90 on its side for connecting the hydraulic and pneumatic pressure supply device 26 for supplying hydraulic and pneumatic pressure to the clamper 74. The robot control device 31 is configured to operate the robot hand 42 and press the supply device button 66d to connect or disconnect the nozzle connection part 90 and the hydraulic and pneumatic pressure supply device 26.

7a and 7b show enlarged views of a position mark 86 as a first photographing portion formed on the claw member 82 of the movable member 78 and an information mark 88 as a second photographing portion formed on the fixed member 84. A circular position mark 86 is formed on the claw member 82 to serve as a reference position when checking the clamped state (FIG. 7a) and unclamped state (FIG. 7b) of the clamper 74 using images captured by the camera 46 of the robot 30. A rectangular information mark 88 is also formed on the fixed member 84 to serve as a reference position when checking the unclamped state and clamped state of the clamper 74. The display surfaces of the position mark 86 and the information mark 88 are displayed facing the same direction, here from the angle plate 72 toward the door 20, so that they can be photographed simultaneously by the camera 46 of the robot 30. The position mark 86 is a plate colored a different color from the claw member 82 and the fixed member 84, or a bolt of a different color screwed into them. The position mark 86 and the information mark 88 may be stickers, tapes, etc. that can be attached. The position mark 86 displays a letter, symbol, or mark (the letter "M" in Figs. 7a and 7b) that allows the orientation of the rotatably configured claw member 82 to be confirmed. A QR code (registered trademark) may be used as the position mark. The information mark 88 uses a QR code (registered trademark) and records a corresponding part number. This allows the robot 30 to photograph the movable member 78 and the fixed member 84 with the camera 46, confirm the unclamped and clamped states of the clamper 74, and confirm the corresponding part number of the work mounting table 16. In the following description, the position mark 86 is formed in a circular shape when viewed from the front, and the information mark 88 is formed in a rectangular shape when viewed from the front, but this is not limited to the above, and the position mark and the information mark may be formed in other shapes such as a polygonal shape other than a circle or a rectangle.

The robot 30 is configured to check the unclamped and clamped states of the clamper 74, i.e., to judge the state, by comparing a reference image previously recorded in the robot control device 31 with an image captured by the camera 46. Specifically, the relative positional relationship between the position mark 86 and the information mark 88 in the captured image is compared with the relative positional relationship in the reference image. The comparison with the reference image is also performed based on the images of the movable member 78 and the fixed member 84. The first center point 86b of the position mark 86 and each side of the information mark 88 are used as the reference positions, i.e., the reference points, for comparison. If the position mark is not circular, another reference point may be provided in place of the first center point 86b. Also, a point identified by another logic, such as the topmost or bottommost vertex of the information mark, may be used. As the relative positional relationship of these reference points, in the clamped state, as shown in FIG. 7a, the horizontal lateral distance XC and the vertical distance YC between the first center point 86b of the position mark 86 and one side of the information mark 88 in the reference image, and the horizontal front-back distance ZC between the first center point 86b of the position mark 86 and the second end point 88a of the information mark 88 are used. In the unclamped state, as shown in FIG. 7b, the horizontal lateral distance XU and the vertical distance YU between the first center point 86b of the position mark 86 and one side of the information mark 88, and the horizontal front-back distance ZU between the first center point 86b of the position mark 86 and the second end point 88a of the information mark 88 are used.

FIG. 8 shows a circuit diagram of the oil/air pressure supply device 26. The oil/air pressure supply device 26 is equipped with an oil/air pressure unit HP for setting the oil/air pressure, and a pressure switch PS configured to switch between open and closed when the oil/air pressure reaches a set pressure. In addition, a solenoid valve SN and a pressure reducing valve RV are attached between the oil/air pressure unit HP and the oil/air pressure supply device 26, and are configured to open and close according to the oil/air pressure inside the oil/air pressure supply device 26.

The hydraulic/pneumatic supply device 26 is connected to the nozzle connection 90 of the angle plate 72 via a coupler CP arranged on the machine tool 12 side. This allows hydraulic/pneumatic pressure from the hydraulic/pneumatic supply device 26 to be supplied to the clamper 74 of the angle plate 72. The nozzle connection 90 is also connected to the hydraulic/pneumatic unit HP arranged on the machine tool 12 via a solenoid valve SN and a pressure switch PS. This allows hydraulic/pneumatic pressure to be supplied to the clamper 74 from the hydraulic/pneumatic unit HP on the machine tool 12 side as well. Furthermore, an accumulator AC is arranged between the clamper 74 and the nozzle connection 90 to supply auxiliary pressure to the clamper 74.

As shown in Figures 6a and 6b, a pressure gauge 92 for monitoring the pressure of the clamper 74 is disposed on the upper surface side of the angle plate 72. As shown in Figures 9a and 9b, an analog pressure gauge 92 having a guide needle 94 is used here. As shown in Figure 9a, when a predetermined pressure is supplied to the clamper 74, the guide needle 94 points to the right of the reference scale SS when viewed from the front, at about 12 o'clock in the figure. Also, as shown in Figure 9b, when pressure is not sufficiently supplied to the clamper 74 and is below a predetermined pressure, the guide needle 94 points to the left of the reference scale SS when viewed from the front, at about 8 o'clock in the figure. The robot control device 31 is configured to operate the camera 46 to photograph the pressure gauge 92 and determine whether a predetermined pressure is being supplied to the clamper 74 from the positional relationship between the guide needle 94 and the reference scale SS. Note that, although the pressure gauge 92 has been described here as being analog, this is not limiting, and the pressure gauge may be digital, for example, and may be configured to determine whether a predetermined pressure is being supplied from an image of the digitally displayed pressure value captured by a camera.

The effect of the workpiece mounting/removal system 10 according to this embodiment will be explained through an explanation of the procedure for mounting/removing the workpiece W using the flowchart shown in FIG. 10.

(Positioning of the robot 30 and the automated guided vehicle 32)
As shown in Fig. 10, in step S001, the upper control system 48 moves the automatic guided vehicle 32 to a reference position in front of the station 14. In step S002, the camera 46 photographs the station 14, and compares it with reference image data when the automatic guided vehicle 32 stops at the reference position, which is stored in advance in the robot control device 31, and if there is a deviation from the reference position, the distance of the deviation is confirmed (A in Fig. 10). Here, if the distance of the automatic guided vehicle 32 from the reference position is equal to or greater than a threshold (A1 in Fig. 10), the process proceeds to step S003, where the automatic guided vehicle 32 is moved so as to reduce the distance of the deviation, the camera 46 photographs the station 14, and the image is compared with the reference image data. As a result, if the distance of the automatic guided vehicle 32 from the reference position becomes less than the threshold (A2 in Fig. 10), the process proceeds to step S004, where the position of the robot hand 42 is corrected so as to further reduce the deviation, and then the process proceeds to step S005.

Next, in step S005, the camera 46 photographs the workpiece placement stage 24's placement stage position mark 50 and placement stage information mark 52, and compares this with reference image data stored in advance in the robot control device 31 when the automated guided vehicle 32 is in a reference position relative to the workpiece placement stage 24, and if there is any deviation from the reference position, the distance of deviation is confirmed (B in Figure 10). Also, the robot control device 31 records the part number to be loaded on the workpiece placement stage 24. Furthermore, the robot control device 31 confirms whether or not a workpiece W is loaded on the workpiece placement stage 24 based on the image of the workpiece placement stage 24 photographed by the camera 46. If a workpiece W is loaded on the workpiece placement stage 24 of the workpiece W, the vacant workpiece number of the part to be loaded is recorded in the robot control device 31. If the deviation from the workpiece placement table 24 is equal to or greater than the threshold value, or if the comparison is not possible because the workpiece placement table 24 is not installed (B1 in FIG. 10), the process proceeds to step S006, and the robot control device 31 outputs an alarm to the upper control system 48. The upper control system 48 that has output the alarm moves the automated guided vehicle 32 to another station 15. If the deviation from the workpiece placement table 24 is less than the threshold value (B2 in FIG. 10), in step S007, the robot control device 31 corrects the position of the robot hand 42 to further reduce the deviation, completes positioning, and proceeds to step S008.

(Opening of door 20 of station 14)
In step S008, the door 20 of the station 14 is photographed by the camera 46, and compared with the reference image data of the door 20 when it is open and when it is closed, which are stored in advance in the robot control device 31, to confirm the state of the door 20 (C in FIG. 10). If there is a deviation between the reference image of the door 20 when it is closed and the deviation distance is less than a threshold, it is determined that the door 20 is closed, and the process proceeds to step S009 (C1 in FIG. 10). In step S009, the robot control device 31 operates the robot hand 42 to press the lock operation button 66a. This releases the door lock, and the process proceeds to step S010. In step S008, if the deviation distance from the reference image of the door 20 when it is open and when it is closed is equal to or greater than a threshold, that is, if it is in an intermediate position between the open state and the closed state (C2 in FIG. 10), the process also proceeds to step S010.

In step S010, the robot control device 31 operates the robot hand 42 to open the door 20. Specifically, the robot hand 42 moves from a position slightly to the left of the door handle 20a attached to the door 20 (the side that closes the door 20) to the right (the side that opens the door 20) while contacting the door handle 20a, and opens the door 20 by sliding it. When the door 20 is opened, the process proceeds to step S011, where the camera 46 takes an image of the door 20 and compares it with the reference image data when the door 20 is open to confirm whether the door 20 is open or not (D in FIG. 10). Here, if the distance by which the door 20 has shifted from the reference position when the door 20 is open is equal to or greater than the threshold value, the process proceeds to step S012, where the robot control device 31 outputs an alarm to the upper control system 48. The upper control system 48 that has output the alarm moves the automatic guided vehicle 32 to another station 15 (D1 in FIG. 10).

If, in step S008, the distance by which the door 20 has shifted from the reference position when the door 20 is open is less than the threshold value (C3 in FIG. 10), or if, in step S011, it is confirmed that the door 20 is open (D2 in FIG. 10), the process proceeds to step S013.

(Removal of the machined workpiece W)
In step S013, the robot control device 31 operates the robot hand 42 to press the supply device button 66d. This connects the nozzle connection part 90 of the angle plate 72 in the station 15 to the hydraulic/pneumatic supply device 26. The robot control device 31 also operates the camera 46 to take an image of the information mark 88 of the fixed member 84 on the angle plate 72, and compares it with reference image data of the fixed member 84 previously stored in the robot control device 31 to confirm the distance displaced from the reference position. If the displaced distance is greater than a predetermined threshold, the upper control system 48 operates the robot hand 42 to correct the position of the robot hand 42. Furthermore, the camera 46 takes an image of the corresponding part number displayed on the fixed member 84 and records it in the robot control device 31. It is confirmed whether this matches the corresponding part number of the workpiece placement table 24 previously recorded in the robot control device 31 (E in FIG. 10). If the corresponding part number displayed on the fixed member 84 does not match the corresponding part number on the workpiece placement table 24 (E1 in FIG. 10), the process proceeds to step S014, and the robot control device 31 outputs an alarm to the upper control system 48. The upper control system 48 that has received the alarm moves the automatic guided vehicle 32 to another station 15.

On the other hand, if the corresponding part number displayed on the fixing member 84 matches the corresponding part number on the workpiece placement table 24 (E2 in FIG. 10), the process proceeds to step S015. In step S015, if a machined workpiece W is fixed to the angle plate 72, the robot control device 31 operates the robot hand 42 to press the workpiece clamp button 66b. This causes the movable member 78 of the clamper 74 to rotate, disengaging the claw member 82 from the workpiece W, and the clamper 74 enters an unclamped state.

Then, the process proceeds to step S016, where the robot control device 31 simultaneously photographs the information mark 88 of the fixing member 84 of the angle plate 72 and the position mark 86 of the claw member 82 to check whether the unclamped state has been reached normally. Here, two-way images, a plan view and a front view of the information mark 88 and the position mark 86, are obtained by photographing from two directions, the vertical upper side and the horizontal front side. Note that when a 3D camera or a stereo camera is used as the camera 46, the image obtained in one photographing may be decomposed into two-way images, for example, an image from the front and an image from the depth direction, and used. After photographing, the process proceeds to step S017, where the relative positional relationship between the position mark 86 and the information mark 88 in the reference image of the unclamped state stored in advance in the robot control device 31 is compared with the relative positional relationship between the position mark 86 and the information mark 88 in the photographed image (F in FIG. 10). Specifically, the horizontal lateral distance XU and the vertical distance YU between the first center point 86b of the position mark 86 and one side of the information mark 88 in the reference image in the unclamped state, and the horizontal front-rear distance ZU between the first center point 86b of the position mark 86 and the second end point 88a of the information mark 88 (see FIG. 7b for all) are compared with the distances in the captured image, and the difference from the reference distance, i.e., the distance difference, is confirmed. Here, if at least one of the distance differences between the horizontal lateral distance XU, the vertical distance YU, and the horizontal front-rear distance ZU is equal to or greater than the threshold (F1 in FIG. 10), the process proceeds to step S018, and the robot control device 31 operates the robot hand 42 to press the work clamp button 66b. As a result, the movable member 78 of the clamper 74 rotates, and the claw member 82 engages with the work W, so that the clamper 74 is in the clamped state. Furthermore, the process proceeds to step S019, and the robot control device 31 operates the robot hand 42 to press the work clamp button 66b. This causes the movable member 78 of the clamper 74 to rotate and disengage the claw member 82 from the workpiece W, causing the clamper 74 to return to the unclamped state.

When the unclamped state is resumed, the process proceeds to step S020, and the robot control device 31 again operates the camera 46 to simultaneously photograph the information mark 88 of the fixed member 84 of the angle plate 72 and the position mark 86 of the claw member 82 from the vertically upward side and the horizontally forward side. Next, the process proceeds to step S021, and the horizontal lateral distance XU and the vertical distance YU between the first center point 86b of the position mark 86 and one side of the information mark 88 in the reference image, as well as the horizontal front-back distance ZU between the first center point 86b of the position mark 86 and the second end point 88a of the information mark 88, are compared with the photographed image to confirm the distance difference (G in FIG. 10). Here, if at least one of the distance differences between the horizontal lateral distance XU, the vertical distance YU, and the horizontal front-back distance ZU is equal to or greater than the threshold value (G1 in FIG. 10), the process proceeds to step S022, and the robot control device 31 operates the robot hand 42 to press the work clamp button 66b. This causes the movable member 78 of the clamper 74 to rotate and clamp the workpiece W. Furthermore, the robot control device 31 outputs an alarm to the upper control system 48. The upper control system 48 that has received the alarm output moves the automated guided vehicle 32 to another station 15.

On the other hand, if the horizontal lateral spacing XU, the vertical spacing YU, and the horizontal front-rear spacing ZU are all less than the threshold (F2 and G2 in FIG. 10), the process proceeds to step S023, and the robot control device 31 determines that the workpiece W has been properly unclamped, and proceeds to step S024. In step S024, the robot 30 operates the robot hand 42 to grasp the unclamped workpiece W, and moves to the workpiece placement table 24 by the automated guided vehicle 32, where the workpiece W is stored.

(Installation of unprocessed workpiece W)
After removing and putting away the machined workpiece W, the robot 30 starts mounting an unmachined workpiece W for the next machining. In step S025, the robot control device 31 operates the camera 46 to take an image of the placement table position mark 50 and placement table information mark 52 on the material placement table 22, and compares the image with reference image data when the unmanned transport vehicle 32 is in a reference position relative to the material placement table 22, which is stored in advance in the robot control device 31, and checks the distance of deviation from the reference position if there is any deviation. If the distance of deviation is equal to or greater than a threshold, the robot control device 31 operates the robot hand 42 to correct its position. Furthermore, the robot control device 31 records the corresponding part numbers in the robot control device 31, and checks whether these corresponding part numbers match the corresponding part numbers displayed on the fixed member 84 (H in FIG. 10). If the corresponding part numbers displayed on the fixed member 84 do not match the corresponding part numbers on the material placement table 22 (H1 in FIG. 10), the robot control device 31 moves to step S026 and outputs an alarm to the upper control system 48. The host control system 48 which has received the alarm output moves the automated guided vehicle 32 to another station 15 .

(Clamping of unmachined workpiece W)
If the corresponding part number displayed on the fixed member 84 matches the corresponding part number on the material placement table 22, the process proceeds to step S027, where the robot control device 31 actuates the robot hand 42 to grip the unmachined workpiece W on the material placement table 22 and place the workpiece W on the workpiece placement portion 76 of the angle plate 72. Next, the process proceeds to step S028, where the robot control device 31 actuates the robot hand 42 to press the work clamp button 66b. This causes the movable member 78 of the clamper 74 to rotate and the claw members 82 to engage with the workpiece W, so that the clamper 74 enters a clamped state.

Then, proceeding to step S029, in order to check whether the clamped state has been reached normally, the robot control device 31 operates the camera 46 to simultaneously photograph the information mark 88 of the fixing member 84 of the angle plate 72 and the position mark 86 of the claw member 82. The photographs are taken from two directions: from above in the vertical direction so that the photographed image is a plan view of these, and from the front in the horizontal direction so that the photographed image is a front view of these. After photographing, the robot control device 31 compares the relative positional relationship between the position mark 86 and the information mark 88 in a reference image of the clamped state that has been stored in advance in the upper control system 48 with the relative positional relationship between the position mark 86 and the information mark 88 in the photographed image (J1 in Figure 10). Specifically, the horizontal lateral distance XC and vertical distance YC between the first center point 86b of the position mark 86 and one side of the information mark 88 in the reference image in the clamped state, as well as the horizontal front-to-back distance ZC between the first center point 86b of the position mark 86 and the second end point 88a of the information mark 88 (all see FIG. 7a) are compared with the captured image to check the difference from the reference distance, i.e., the distance difference.

Here, if at least one of the differences in the horizontal lateral distance XC, the vertical distance YC, and the horizontal front-rear distance ZC is equal to or greater than the threshold value, the process proceeds to step S030, and the robot control device 31 records the position of the clamper 74 where the difference in the distance is equal to or greater than the threshold value. Next, the process proceeds to step S031, and the robot control device 31 operates the robot hand 42 to press the work clamp button 66b. This causes the movable member 78 of the clamper 74 to rotate, and the engagement of the claw member 82 with the work W is released, so that the clamper 74 is in an unclamped state. Furthermore, the process proceeds to step S032, and the robot control device 31 operates the robot hand 42 to grasp the work W and temporarily move it to the temporary placement table 23 on the material placement table 22. Next, the process proceeds to step S033, and the robot control device 31 operates the robot hand 42 to pull out the air nozzle 68 from the storage position of the station 14, and cleans the clamper 74 and the attachment position of the work W and the surrounding areas thereof. This can eliminate any problem in the clamper 74 that would prevent it from being properly clamped due to dirt or the like being caught in it. Then, the process moves to step S034, where the robot control device 31 operates the robot hand 42 to grasp the workpiece W on the temporary placement table 23 and place it on the workpiece placement section 76. Next, the process moves to step S035, where the robot control device 31 operates the robot hand 42 to press the workpiece clamp button 66b. This causes the movable member 78 of the clamper 74 to rotate and the claw members 82 to engage with the workpiece W, so that the clamper 74 is in a clamped state.

When the workpiece W is clamped by the clamper 74, the process proceeds to step S036, where the camera 46 simultaneously photographs the information mark 88 of the fixed member 84 of the angle plate 72 and the position mark 86 of the claw member 82 to check whether the workpiece has been clamped normally. The photographs are taken from two directions: from above in the vertical direction so that the photographed image is a plan view of these, and from the front in the horizontal direction so that the photographed image is a front view of these. Once the photographs have been taken, the relative positional relationship between the position mark 86 and the information mark 88 in a reference image of the clamped state that is pre-stored in the robot control device 31 is compared with the relative positional relationship between the position mark 86 and the information mark 88 in the photographed image (K in Figure 10). Specifically, the horizontal lateral distance XC and vertical distance YC between the first center point 86b of the position mark 86 and one side of the information mark 88 in the reference image in the clamped state, as well as the horizontal front-to-back distance ZC between the first center point 86b of the position mark 86 and the second end point 88a of the information mark 88 (all see FIG. 7a) are compared with the captured image to confirm the distance difference.

Here, if at least one of the differences in the horizontal lateral distance XC, the vertical distance YC, and the horizontal front-rear distance ZC is equal to or greater than the threshold value, the process proceeds to step S037, where the robot hand 42 is operated to press the work clamp button 66b. This causes the movable member 78 of the clamper 74 to rotate, and the claw member 82 to disengage from the work W, causing the clamper 74 to enter an unclamped state. Furthermore, the robot control device 31 operates the robot hand 42 to clamp the unclamped work W and return the work W to the temporary placement table 23 of the material placement table 22. When the work W is placed on the temporary placement table 23, the robot control device 31 outputs an alarm to the upper control system 48. The upper control system 48 that has output the alarm moves the automated guided vehicle 32 to another station 15 (K1 in FIG. 10).

If the horizontal lateral spacing XC, the vertical spacing YC, and the horizontal front-rear spacing ZC are all less than the threshold (J2/K2 in FIG. 10), the process proceeds to step S038, and the robot control device 31 operates the camera 46 to photograph the pressure gauge 92, and determines whether or not a pressure equal to or greater than the threshold is being supplied to the clamper 74 based on the photographed image (L in FIG. 10). If the pressure is less than the threshold, the process proceeds to step S039, and the robot control device 31 operates the robot hand 42 to press the work clamp button 66b. This causes the movable member 78 of the clamper 74 to rotate, and the engagement of the claw member 82 with the work W is released, so that the clamper 74 is in an unclamped state. Furthermore, the robot control device 31 operates the robot hand 42 to clamp the work W and move it to the temporary placement table 23 on the material placement table 22. When the work W is placed on the temporary placement table 23, the robot control device 31 outputs an alarm to the upper control system 48. The host control system 48 that received the alarm output moves the automated guided vehicle 32 to another station 15 (L1 in Figure 10).

If in step S038 the robot control device 31 determines that a pressure equal to or greater than the threshold is being supplied to the clamper 74, the process proceeds to step S040, where the robot control device 31 operates the robot hand 42 to press the supply device button 66d to disconnect the nozzle connection part 90 of the angle plate 72 from the hydraulic and pneumatic supply device 26. When the hydraulic and pneumatic supply device 26 is disconnected, the robot control device 31 operates the camera 46 to photograph the pressure gauge 92, and determines based on the photographed image whether or not a pressure equal to or greater than the threshold is being supplied to the clamper 74 even after the hydraulic and pneumatic supply device 26 has been disconnected (M in FIG. 10).

If the pressure is less than the threshold, the process proceeds to step S041, where the robot control device 31 operates the robot hand 42 to press the supply device button 66d to reconnect the nozzle connection part 90 of the angle plate 72 to the hydraulic/pneumatic supply device 26. The robot control device 31 also operates the robot hand 42 to press the work clamp button 66b. This causes the movable member 78 of the clamper 74 to rotate, and the claw member 82 to disengage from the work W, so that the clamper 74 enters an unclamped state. The robot control device 31 also operates the robot hand 42 to clamp the unclamped work W and move it to the temporary placement table 23 on the material placement table 22. When the robot control device 31 places the work W on the temporary placement table 23, it outputs an alarm to the upper control system 48. The upper control system 48 that has output the alarm moves the automated guided vehicle 32 to another station 15 (M1 in FIG. 10).

If the pressure is equal to or greater than the threshold, the process proceeds to step S042, where the robot control device 31 activates the robot hand 42 to close the door 20. Specifically, the robot hand 42 moves from a position slightly to the right of the door handle 20a (the side that opens the door 20) to the left (the side that closes the door 20) while contacting the door handle 20a, and closes the door 20 by sliding the door 20. When the robot control device 31 has closed the door 20, it activates the robot hand 42 to press the lock operation button 66a to lock the door 20. Furthermore, by activating the robot hand 42 to press the work set complete button 66c, it is possible to communicate to the machine tool 12 that the setting of the workpiece W has been completed.

In the workpiece attachment/detachment system 10 according to this embodiment, the robot 30 has a robot hand 42 configured to be able to grasp the workpiece W, and can be moved by an automated guided vehicle 32 that can move in any direction. Therefore, the upper control system 48 operates the automated guided vehicle 32 on which the robot 30 is placed to move the robot 30 to the

stations

14 and 15, and the robot control device 31 operates the robot hand 42 of the robot 30 to place the workpiece W on the workpiece mounting table 16. This allows the robot 30 to be moved appropriately to the

stations

14 and 15 where the workpiece W needs to be attached or detached, rather than placing the robot 30 at each of the

stations

14 and 15, and allows the robot 30 to be used to efficiently attach and detach the workpiece W.

Furthermore, according to the workpiece mounting/removal system 10 of this embodiment, the robot 30 has a camera 46 configured to be able to photograph the movable member 78 and the fixed member 84 at a reference position for photographing, and can be moved to the photographing position by the automatic guided vehicle 32. The upper control system 48 moves the robot 30 to the photographing position by operating the automatic guided vehicle 32 on which the robot 30 is placed, and the robot control device 31 can simultaneously photograph the movable member 78 and the fixed member 84 by operating the camera 46. Therefore, the robot control device 31 can determine the mounting/removal state of the workpiece W with respect to the workpiece mounting table 16 based on the images of the movable member 78 and the fixed member 84 that have been photographed, and can continue processing if it is determined that the workpiece W is properly mounted on the workpiece mounting table 16. In addition, if the robot control device 31 determines that the workpiece W is not properly mounted on the workpiece mounting table 16, the upper control system 48 can include, for example, a process of operating the clamper 74 and the robot 30 to once unclamp the workpiece W and then clamp it again, or a process of interrupting processing to improve clamping. This allows the process of checking for and resolving malfunctions in

stations

14 and 15 to be included, and allows the robot 30 to efficiently load and unload the workpiece W.

Furthermore, according to the workpiece mounting/removal system 10 of this embodiment, the movable member 78 is formed with a position mark 86 whose orientation changes when the movable member 78 is actuated. Furthermore, the fixed member 84 is formed with an information mark 88. The display surfaces of the position mark 86 and the information mark 88 are both displayed facing the direction from the angle plate 72 toward the door 20, and can be photographed simultaneously by the camera 46. This makes it possible to clarify the reference position of the image photographed by the camera 46. Furthermore, the comparison with the reference image is performed here based on images of the movable member 78 and the fixed member 84 photographed from the vertically upward side and the horizontally forward side. This makes it possible to reliably determine the relative positional relationship between the movable member 78 and the fixed member 84, i.e., the clamped or unclamped state, and efficiently mount and remove the workpiece W using the robot 30.

Furthermore, according to the workpiece attachment/detachment system 10 of this embodiment, when the robot control device 31 determines that the workpiece W is not properly clamped, i.e. that the workpiece W is not properly clamped, it operates the robot hand 42 to grasp the workpiece W and temporarily move it to the temporary placement table 23 on the material placement table 22. After moving the workpiece W, the robot control device 31 is configured to operate the robot hand 42 to pull out the air nozzle 68 from its storage position in the station 14 and clean the clamper 74 and the attachment position of the workpiece W and their surroundings. Therefore, if the clamper 74 is not properly clamped due to the presence of dirt or the like, this can be resolved. This allows the workpiece W to be stably and reliably clamped, and the workpiece W can be efficiently attached and detached using the robot 30.

In addition, according to the workpiece mounting and demounting system 10 of this embodiment, the workpiece mounting table 16 is provided with a pressure gauge 92 for displaying the pressure supplied to the clamper 74 by the hydraulic and pneumatic supply device 26. When the workpiece W is clamped and the hydraulic and pneumatic supply device 26 is disconnected, the robot control device 31 operates the camera 46 to photograph the pressure gauge 92, and can determine whether or not a pressure equal to or greater than the threshold value is being supplied to the clamper 74 even after the hydraulic and pneumatic supply device 26 is disconnected, based on the photographed image. Here, if the pressure is less than the threshold value, the robot control device 31 is configured to operate the robot hand 42 to press the supply device button 66d, thereby reconnecting the nozzle connection part 90 of the angle plate 72 to the hydraulic and pneumatic supply device 26. In addition, the robot control device 31 is configured to operate the robot hand 42 to press the workpiece clamp button 66b, thereby rotating the movable member 78 of the clamper 74 to release the engagement of the claw member 82 with the workpiece W, and to place the clamper 74 in an unclamped state. Furthermore, the robot control device 31 is configured to operate the robot hand 42 to clamp the unclamped workpiece W and move it onto the temporary placement table 23 of the material placement table 22. This allows the processing of the workpiece W to be interrupted in order to prioritize resolving any malfunctions found in

stations

14 and 15, and allows the robot 30 to efficiently load and unload the workpiece W.

As described above, the workpiece mounting/removal system 10 according to this embodiment can efficiently mount and remove the workpiece W using the robot 30.

(Modification)
Hereinafter, a modified example of the workpiece mounting and unmounting system 10 according to the present embodiment will be described. Elements similar to or corresponding to those in the present embodiment will be given the same reference numerals, and duplicated descriptions will be omitted.

In the modified workpiece mounting/removal system 10, a pallet 102 extending horizontally is placed on the plate base 70 of the workpiece mounting table 16. The four clampers 74 are arranged above the pallet 102 and are configured to clamp the workpiece W placed on the upper surface of the pallet 102. In addition, the pressure gauge 92 is arranged above the nozzle connection part 90.

The robot 30 is configured to confirm, i.e., judge, the unclamped and clamped states of the clamper 74 by comparing a reference image previously recorded in the robot control device 31 with an image captured by the camera 46. Specifically, the relative positional relationship between the position mark 86 and the information mark 88 in the captured image is compared with the relative positional relationship in the reference image. As the relative positional relationship in the reference image, in the clamped state, the horizontal lateral distance XC and horizontal front-to-back distance YC between the first center point 86b of the position mark 86 and one side of the information mark 88 in the reference image captured from above, and the vertical distance ZC between the first center point 86b of the position mark 86 and the second end point 88a of the information mark 88 in the reference image captured from the front are used. In addition, in the unclamped state, the horizontal lateral distance XU and horizontal front-to-back distance YU between the first center point 86b of the position mark 86 and one side of the information mark 88 in the reference image captured from above, as well as the vertical distance ZU between the first center point 86b of the position mark 86 and the second end point 88a of the information mark 88 in the reference image captured from the front, are used.

In the workpiece mounting/removal system 10 according to the modified example, the robot control device 31 can determine the mounting/removal state of the workpiece W on the workpiece mounting table 16 based on the image captured by the camera 46, and can continue processing if it determines that the workpiece W is properly mounted on the workpiece mounting table 16. Furthermore, if the robot control device 31 determines that the workpiece W is not properly mounted on the workpiece mounting table 16, the upper control system 48 can suspend processing if it determines that the workpiece W is not properly mounted, even if, for example, the clamper 74 and the robot 30 are operated to unclamp the workpiece W and then clamp it again. This makes it possible to include a process for resolving any defects found in the

stations

14 and 15, and to efficiently mount and remove the workpiece W using the robot 30.

In the above description, the robot hand 42 presses the four

operation buttons

66a, 66b, 66c, and 66d located on the side of the door 20, but this is not limiting and may be automated, for example, by communication from a higher-level control system.

In addition, the hydraulic and pneumatic supply device 26 has been described here as being connected from the side of the work mounting table 16, but this is not limited thereto, and it may be, for example, an upper online hydraulic supply device that is connected to the upper side of the work mounting table.

Furthermore, the clamper 74 has been described here as rotating the shaft member 80 to engage the claw member 82 with the workpiece W, but this is not limited to the above, and other types of clampers, such as a link clamp or a linear clamp, may also be used.

Furthermore, although the work mounting table 16 has been described here as being disposed inside the

stations

14 and 15, this is not limiting, and for example, the work mounting table may be used alone.

The above describes an embodiment of the workpiece attachment/detachment system 10, but the present invention is not limited to the above embodiment. It is believed that a person skilled in the art would understand that various modifications of the above embodiment are possible.

10 Workpiece mounting/removal system 14 Station (workpiece mounting device)
15 Station (Work mounting device)
16 Workpiece mounting table 30 Robot 31 Robot control device (control device)
32 Automated guided vehicle (mobile body)
42 Robot Hand (Hand)
46 Camera 48 Upper control system (control device)
68 Air nozzle (cleaning means)
74: clamper; 78: movable member; 84: fixed member; 86: position mark (first photographing unit)
88 Information mark (second photographing part)
92 Pressure gauge 100 Work mounting stand W Work

Claims

A workpiece loading/unloading system for loading/unloading a workpiece for machining, comprising:
a work mounting device including a work mounting table for mounting the work, a clamper for mounting or removing the work on the work mounting table by operating a movable member, and a fixing member fixed near the clamper;
a robot having a hand configured to be able to grip the workpiece and a camera configured to be able to photograph the movable member and the fixed member at a photographing position;
a moving body on which the robot is placed and which is movable in any direction in order to move the robot to the photographing position;
A control device for operating the clamper, the robot, and the camera, the control device determining a mounting/removal state of the workpiece with respect to the workpiece mounting table based on an image captured by the camera,
A workpiece attachment/detachment system characterized in that the camera simultaneously photographs the movable member and the fixed member.
a first imaging unit formed on the movable member and whose position changes as the movable member is actuated;
A second imaging unit formed on the fixed member,
The workpiece mounting/removal system according to claim 1, characterized in that the first photographing unit and the second photographing unit face the camera in the same direction, and the camera photographs the first photographing unit and the second photographing unit simultaneously.
The control device determines, based on a positional relationship between the first photographing unit and the second photographing unit in an image photographed by the camera, that the clamper is in a clamping state in which the workpiece is attached to the workpiece mounting table, or in an unclamping state in which the workpiece is removed from the workpiece mounting table;
The workpiece mounting/removal system of claim 2, configured to operate a cleaning means to clean the clamper and the surrounding area of the workpiece when it is determined that the movable member has deviated from the reference position in the clamped state or the unclamped state by more than a threshold value.
the workpiece mounting table is provided with a pressure gauge for indicating pressure supplied to the clamper by a hydraulic and pneumatic pressure supply device,
The workpiece mounting/removal system of claim 3, wherein the control device is configured to detect the pressure value of the clamper from an image of the pressure gauge captured by the camera, and remove the workpiece from the workpiece mounting table if the pressure value is below a threshold value.