Robot-mounted mobile device and its control method

Abstract

To provide a robot mounting mobile device which can carry out an operation accurately, and a control method therefor.SOLUTION: There are a machine tool 10, a robot 25 having a camera 31, and a carrier device mounted with the robot 25. An identification drawing corresponding to the machine tool 10 is arranged.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a robot-mounted mobile device that is equipped with a robot that performs work on a machine tool and can move to a work position set for the machine tool, and a control method for the same. [Background technology]

[0002] A conventional system is disclosed in JP 2017-132002 A (Japanese Patent Application Publication No. 2017-132002, Patent Document 1 below). In this system, an automated guided vehicle equipped with a robot moves to a work position set for a machine tool, and at the work position, the robot performs work such as attaching and detaching a workpiece to and from the machine tool.

[0003] In such a system, a single robot moved by an automatic guided vehicle can perform tasks such as attaching and detaching workpieces to multiple machine tools, which increases the degree of freedom in the layout of the machine tools compared to when robots are fixedly installed relative to the machine tools, making it possible to set the layout of the machine tools in a way that can further improve production efficiency.Furthermore, compared to conventional systems in which robots are installed in a fixed state, a single robot can perform tasks on a larger number of machine tools, which reduces equipment costs.

[0004] On the other hand, because an automated guided vehicle is self-propelled using wheels, the positioning accuracy of the automated guided vehicle when it stops at the work position is not necessarily high. Therefore, in order for the robot to perform work accurately on a machine tool, it is necessary to compare the posture of the robot when the automated guided vehicle is positioned at the work position with a reference posture of the robot set during so-called teaching, which serves as a control reference, to detect the amount of error, and to correct the working posture of the robot according to the amount of error.

[0005] A known technique for correcting the posture of such a robot is a position correction method such as that disclosed in JP 2016-221622 A (Japanese Patent Application Publication No. 2016-221622, Patent Document 2 listed below). Specifically, this position correction method involves arranging a visual target consisting of two calibration markers on the outer surface of a machine tool, capturing an image of the visual target with a camera attached to a movable part of the robot, measuring the relative positional relationship between the robot and the machine tool based on the obtained image and the position and posture of the camera, and correcting the working posture of the robot based on the measured positional relationship. Summary of the Invention [Problem to be solved by the invention]

[0006] However, with the conventional position correction methods described above, for example, when a robot's hand is inserted into a machine tool and the hand is used to attach or detach a workpiece to or from a chuck of the machine tool, it is not possible to accurately correct the posture of the robot performing this attachment or detachment work.

[0007] In other words, since the unmanned guided vehicle is configured to move by the operation of wheels with a relatively high degree of freedom, the surface on which the robot is mounted is prone to tilt relative to the floor, and this tilt is prone to fluctuate depending on changes in the posture of the mounted robot, in other words, depending on changes in the position of the robot's center of gravity.

[0008] Therefore, when the robot takes a position in which its hand has entered the machine tool when the workpiece is being attached or detached as described above, in other words, when the robot's arm is in a state in which it significantly overhangs the unmanned transport vehicle, the inclination of the placement surface described above will be greater than the inclination when the robot's hand is outside the machine tool and the arm does not overhang the unmanned transport vehicle, or if it does overhang, it is only slightly.

[0009] Therefore, even if a visual target, which is a calibration marker, is placed on the outer surface of the machine tool, as in the conventional position correction method described above, and the position correction amount (posture correction amount) of the robot is obtained when the robot is outside the machine tool, the obtained position correction amount cannot be used to accurately correct the posture of the robot for workpiece attachment / detachment operations performed when the robot's hand is inside the machine tool.

[0010] Furthermore, if the robot's posture cannot be accurately corrected when attaching or detaching a workpiece, the robot hand cannot be accurately positioned relative to the chuck. For example, if the chuck is a collet chuck or other chuck in which the movement (stroke) of the gripping part is very small, i.e., the clearance between the workpiece and the chuck is very small, there is a possibility that the workpiece will not be securely gripped by the chuck.

[0011] If the workpiece cannot be reliably attached and detached, the system's availability will decrease, and the system will not be able to achieve unmanned operation with good production efficiency.

[0012] Furthermore, in the position correction method disclosed in Patent Document 2, two calibration markers are imaged by cameras, respectively, which requires a long operation time for the robot to image the calibration markers, thereby reducing the production efficiency of the system. [Means for solving the problem]

[0013] Therefore, the present disclosure provides a robot-mounted mobile device and a control method thereof as set forth in the claims.

[0014] As described above, according to the present disclosure, the robot's posture is corrected using an identification figure placed inside the machine tool on which the robot actually works, so that the posture can be accurately corrected, and this allows the robot to perform tasks with high precision, even when the tasks require high operational accuracy. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a plan view showing a schematic configuration of a system according to an embodiment of the present invention.

[0016] [Figure 2] 1 is a block diagram showing the configuration of a system according to an embodiment of the present invention.

[0017] [Figure 3] 1 is a perspective view showing an automated guided vehicle and a robot according to an embodiment of the present invention.

[0018] [Figure 4] FIG. 2 is an explanatory diagram for explaining an imaging posture of the robot according to the embodiment.

[0019] [Figure 5] FIG. 2 is an explanatory diagram showing an identification graphic according to the embodiment;

[0020] [Figure 6] FIG. 4 is an explanatory diagram for explaining a correction amount calculation method in the present embodiment.

[0021] [Figure 7] FIG. 4 is an explanatory diagram for explaining a correction amount calculation method in the present embodiment.

[0022] [Figure 8] FIG. 4 is an explanatory diagram for explaining a correction amount calculation method in the present embodiment.

[0023] [Figure 9] FIG. 4 is an explanatory diagram for explaining position correction in the present embodiment.

[0024] [Figure 10] FIG. 10 is an explanatory diagram showing a modified example in which an identification graphic is arranged in a machine tool. DETAILED DESCRIPTION OF THE INVENTION

[0025] Specific embodiments will be described below with reference to the drawings.

[0026] (First embodiment) As shown in Figures 1 and 2, the system 1 of the first embodiment is composed of a machine tool 10, a material stocker 20 and a product stocker 21 as peripheral devices, an automated guided vehicle 35, a robot 25 mounted on this automated guided vehicle 35, a camera 31 attached to the robot 25, and a control device 40 that controls the robot 25 and the automated guided vehicle 35.

[0027] The machine tool of the first embodiment is configured to have an identification graphic placed within the machine tool. In particular, a configuration in which an identification graphic is placed within the machining area is preferred.

[0028] The robot-mounted moving device of the first embodiment includes a robot having a camera, a hand unit, a first arm unit, and a second arm unit, a control unit that controls the position of the hand unit of the robot, and a moving unit on which the robot is mounted. The moving unit is configured to be movable around the machine tool, etc.

[0029] As shown in Fig. 4, the machine tool 10 is a vertical NC (numerically controlled) lathe equipped with a spindle 11 to which a chuck 12 for gripping a workpiece W (W') is attached, and the spindle 11 is arranged vertically so that the workpiece W (W') can be turned. A tool presetter 13 is provided near the spindle 11 and includes a contact 14 and a support bar 15 that supports the contact 14. The support bar 15 is arranged along the axis of the spindle 11 so as to be movable forward and backward relative to the machining area. A ceramic display plate 16 is provided on the end surface facing the machining area, and the identification symbol shown in Fig. 5 is drawn on the display plate 16. The display plate 16 is arranged to be positioned on a horizontal plane.

[0030] In addition, Figure 4 shows the state in which the support bar 15 and contactor 14 have advanced into the processing area, but when the support bar 15 and contactor 14 retract and the contactor 14 and display plate 16 are stored in the storage area, the shutter 17 closes, isolating the contactor 14 and display plate 16 from the processing area.

[0031] The identification figure in this example has a matrix structure in which a plurality of square pixels are arranged two-dimensionally, and each pixel is displayed in white or black. In FIG. 5, black pixels are shaded. Such identification figures include those called AR markers and April Tags. If the identification figure is small, a lens may be provided on the identification figure so that an enlarged image can be captured by a camera 31, which will be described later.

[0032] The material stocker 20 is disposed to the left of the machine tool 10 in Fig. 1 and is a device for stocking a plurality of materials (unmachined workpieces W) to be machined by the machine tool 10. The product stocker 21 is disposed to the right of the machine tool 10 in Fig. 1 and is a device for stocking a plurality of products or semi-finished products (machined workpieces W') machined by the machine tool 10.

[0033] 1, the robot 25 is mounted on a mounting surface 36, which is the upper surface of the automatic guided vehicle 35, and is also provided with a portable operation panel 37 for an operator. The operation panel 37 is equipped with an input / output unit for inputting and outputting data, an operation unit for manually operating the automatic guided vehicle 35 and the robot 25, and a display capable of displaying information on a screen.

[0034] In addition, the unmanned transport vehicle 35 is equipped with a sensor (for example, a distance measurement sensor using laser light) that can recognize its own position within the factory, and is configured to travel without a track within the factory, including the area where the machine tool 10, material stocker 20, and product stocker 21 are located, under the control of the control device 40, and in this example, passes through each work position set for each of the machine tool 10, material stocker 20, and product stocker 21.

[0035] As shown in Figures 1 and 3, the robot 25 of this embodiment is a multi-joint robot equipped with three arms: a first arm 26, a second arm 27, and a third arm 28. A hand 29 serving as an end effector is attached to the tip of the third arm 28, and a camera 31 is attached via a support bar 30.

[0036] However, this is not a limitation. The robot may have (i) a camera, (ii) a hand for grasping a workpiece or a tool, (iii) a second arm movably connecting the hand, and (iv) a first arm movably connecting the second arm. In comparison with the robot 25 of this embodiment, the hand corresponds to the hand 29, the second arm corresponds to the joint rotatably (movably) connected to the second arm 27, and the first arm corresponds to the joint rotatably (movably) connected to the first arm 26. It should be noted that the joint rotatably and reciprocally (movably) connected to the third arm 28 of the robot of this embodiment may also be interpreted as the second arm. In other words, although the robot has three arms in this embodiment, at least two arms are sufficient.

[0037] As shown in FIG. 2 , the control device 40 of this embodiment is composed of an operation program storage unit 41, a movement position storage unit 42, an operation posture storage unit 43, a map information storage unit 44, a reference image storage unit 45, a manual operation control unit 46, an automatic operation control unit 47, a map information generation unit 48, a position recognition unit 49, a correction amount calculation unit 50, and an input / output interface 51. The control device 40 is connected to the machine tool 10, the material stocker 20, the product stocker 21, the robot 25, the camera 31, the automatic guided vehicle 35, and the operation panel 37 via the input / output interface 51. However, the control device 40 is not limited to this configuration. The control device 40 is only required to have at least a control unit for controlling the position of the robot hand, and other units such as a storage unit may be provided in separate devices.

[0038] The control device 40 is configured as a computer including a CPU, RAM, ROM, etc., and the functions of the manual operation control unit 46, automatic operation control unit 47, map information generation unit 48, position recognition unit 49, correction amount calculation unit 50, and input / output interface 51 are realized by computer programs, and execute the processes described below. The operation program storage unit 41, movement position storage unit 42, operation posture storage unit 43, map information storage unit 44, and reference image storage unit 45 are configured as appropriate storage media such as RAM. In this example, the control device 40 is attached to the automated guided vehicle 35 and is connected to the machine tool 10, material stocker 20, and product stocker 21 by appropriate communication means, and is also connected to the robot 25, camera 31, automated guided vehicle 35, and operation panel 37 by wire or wireless. However, this is not a limitation, and the control device 40 may be installed in an appropriate location other than the automated guided vehicle 35. In this case, the control device 40 is connected to each unit by appropriate communication means.

[0039] The manual operation control unit 46 is a functional unit that operates the automatic guided vehicle 35, the robot 25, and the camera 31 in accordance with operation signals input by an operator from the operation panel 37. That is, the operator can manually operate the automatic guided vehicle 35, the robot 25, and the camera 31 using the operation panel 37 under the control of the manual operation control unit 46.

[0040] The operation program storage unit 41 is a functional unit that stores an automatic driving program for automatically driving the automatic guided vehicle 35 and the robot 25 during production, and a map generation program for operating the automatic guided vehicle 35 when generating map information within a factory, which will be described later. The automatic driving program and the map generation program are input, for example, from an input / output unit provided on the operation panel 37, and stored in the operation program storage unit 41.

[0041] The automatic driving program includes command codes relating to the target position to which the automated guided vehicle 35 is to move, the speed of movement, and the direction of the automated guided vehicle 35, as well as command codes relating to the sequential operations of the robot 25 and command codes relating to the operation of the camera 31. The map generation program also includes command codes for causing the automated guided vehicle 35 to travel tracklessly throughout the factory, so that the map information generation unit 48 can generate map information.

[0042] The map information storage unit 44 is a functional unit that stores map information including the location information of machines, devices, equipment, etc. (devices, etc.) that are located within the factory where the automated guided vehicle 35 travels, and this map information is generated by the map information generation unit 48.

[0043] When the automatic guided vehicle 35 is caused to travel in accordance with the map generation program stored in the operation program storage unit 41 under the control of the automatic driving control unit 47 of the control device 40, which will be described in detail later, the map information generation unit 48 acquires spatial information within the factory from distance data detected by the sensors, recognizes the planar shapes of devices and the like installed within the factory, and recognizes, for example, the positions, planar shapes, and the like (arrangement information) of specific devices installed within the factory, such as machine tool 10, material stocker 20, and product stocker 21 in this example, based on the planar shapes of devices and the like that have been registered in advance. Then, the map information generation unit 48 stores the obtained spatial information and arrangement information of devices and the like in the map information storage unit 44 as map information within the factory.

[0044] The position recognition unit 49 is a functional unit that recognizes the position of the automated guided vehicle 35 within the factory based on the distance data detected by the sensor and the map information within the factory stored in the map information storage unit 44, and the operation of the automated guided vehicle 35 is controlled by the automatic driving control unit 47 based on the position of the automated guided vehicle 35 recognized by this position recognition unit 49.

[0045] The movement position memory unit 42 is a functional unit that stores movement positions as specific target positions to which the automated guided vehicle 35 moves, which correspond to command codes in the operation program, and these movement positions include the respective work positions set for the machine tool 10, material stocker 20, and product stocker 21. Note that these movement positions are set, for example, by manually operating the automated guided vehicle 35 using the operation panel 37 under the control of the manual operation control unit 46 to move it to each target position, and then storing the position data recognized by the position recognition unit 49 in the movement position memory unit 42. This operation is called a teaching operation.

[0046] The movement posture storage unit 43 is a functional unit that stores data relating to movement postures corresponding to command codes in the movement program, which are postures (movement postures) of the robot 25 that change sequentially as the robot 25 moves in a predetermined order. The data relating to movement postures is rotation angle data of each joint (motor) of the robot 25 in each of the target postures when the robot 25 is manually operated to take each target posture by teaching operation using the operation panel 37 under the control of the manual operation control unit 46, and this rotation angle data is stored in the movement posture storage unit 43 as data relating to the movement posture.

[0047] Specific operating postures of the robot 25 are set for each of the material stocker 20, the machine tool 10, and the product stocker 21. For example, for the material stocker 20, the following positions are set as take-out operation positions: a work start position (take-out start position) when work is started in the material stocker 20, each work position (each take-out position) for gripping an unmachined workpiece W stored in the material stocker 20 with the hand 29 and taking it out of the material stocker 20, and a position when the take-out is completed (a take-out completion position, which is the same position as the take-out start position in this example).

[0048] Furthermore, in the machine tool 10, a workpiece removal operation posture for removing the machined workpiece W' from the machine tool 10 and a workpiece mounting operation posture for mounting the unmachined workpiece W on the machine tool 10 are set.

[0049] Specifically, the work removal operation posture may be, for example, a work start posture before entering the machine tool 10; a posture in which the hand 29 and camera 31 enter the machining area of ​​the machine tool 10, the camera 31 is faced directly with an identification figure provided on the support bar 15, and the camera 31 captures an image of the identification figure (image capture posture) (see Figure 4); a posture in which the hand 29 faces the machined work W' held in the chuck 12 of the machine tool 10 (removal preparation posture); a posture in which the hand 29 is moved toward the chuck 12 and the machined work W' held in the chuck 12 is grasped by the hand 29 (grasping posture); a posture in which the hand 29 is moved away from the chuck 12 and the machined work W' is removed from the chuck 12 (removal posture); and a posture in which the hand 29 and camera 31 have left the machine tool 10 (work completion posture). When the camera 31 is placed facing a horizontal identification symbol, the camera 31 is oriented such that its lens is substantially parallel to the identification symbol.

[0050] In addition, the workpiece mounting operation posture may be, for example, a work start posture before entering the machine tool 10, a posture in which the hand 29 and camera 31 enter the machining area of ​​the machine tool 10, the camera 31 is faced directly with an identification figure provided on the support bar 15, and the identification figure is captured by the camera 31 (image capturing posture) (see Figure 4), a posture in which the unmachined workpiece W held by the hand 29 faces the chuck 12 of the machine tool 10 (mounting preparation posture), a posture in which the hand 29 is moved toward the chuck 12 so that the unmachined workpiece W can be grasped by the chuck 12 (mounting posture), a posture in which the hand 29 is separated from the chuck 12 (separation posture), and a posture in which the hand 29 and camera 31 have left the machine tool 10 (work completion posture).

[0051] In the product stocker 21, the work start posture (storage start posture) when work is started in the product stocker 21, each work posture (storage posture) for storing the machined work W' held by the hand 29 in the product stocker 21, and the posture when storage is completed (storage completion posture, which in this example is the same posture as the storage start posture) are set as storage operation postures.

[0052] The automatic driving control unit 47 is a functional unit that uses either the automatic driving program or the map generation program stored in the operation program storage unit 41, and operates the automatic guided vehicle 35, the robot 25, and the camera 31 in accordance with the program. At that time, the data stored in the movement position storage unit 42 and the operation posture storage unit 43 are used as necessary.

[0053] The reference image storage unit 45 is a functional unit that stores, as a reference image, an image obtained by capturing an image of an identification figure provided on the support bar 15 of the tool presetter 13 by the camera 31 when the automatic guided vehicle 35 is at a work position set with respect to the machine tool 10 and the robot 25 is in the imaging posture during a teaching operation.

[0054] When the robot 25 is automatically driven under the control of the automatic driving control unit 47 in accordance with the automatic driving program stored in the operation program memory unit 41, the robot 25 is in an imaging posture and the identification figure is imaged by the camera 31, and based on the current image of the identification figure obtained during the automatic driving and the reference image (image imaged during the teaching operation) stored in the reference image memory unit 45, the correction amount calculation unit 50 estimates the position error amount of the camera 31 between the current posture of the robot 25 and the posture during the teaching operation, which includes the position error amount of the camera 31 in two mutually perpendicular axis directions set in a plane parallel to the identification figure, and the rotation error amount of the camera 31 around a vertical axis perpendicular to the plane, and calculates the correction amount for the acting part in the working posture based on each estimated error amount.

[0055] Fig. 6 shows an image of the identification pattern captured by the camera 31 during the teaching operation, i.e., the reference image. In the figure, the solid rectangular line is the field of view of the camera 31, in other words, the outline of the reference image. Fig. 7 also shows, in solid lines, an image of the current identification pattern obtained during automatic driving. In Fig. 7, the solid rectangular line is the outline of the current image, and the dashed rectangular line is the outline of the reference image. Fig. 7 shows that a discrepancy has occurred between the image capturing posture during the teaching operation of the robot 25 and the current image capturing posture, resulting in a discrepancy between the reference image and the current image.

[0056] The correction amount calculation unit 50 first analyzes the reference image shown in FIG. 6 during the teaching operation, and calculates, for example, the reference image, in other words, the geometric coordinate system (x t axis-y t axis coordinate system) based on the preset figure coordinate system (x t axis-y t The position (x) of the camera 31 in the robot coordinate system (x-axis-y-axis coordinate system) during teaching is calculated according to the conversion formula between the robot coordinate system (x-axis coordinate system) and the robot coordinate system (x-axis-y-axis coordinate system). teach ,y teach ,rz teach ) is calculated. The x-axis and y-axis are two axes that are parallel to the identification figure and perpendicular to each other, and are the coordinate system of the robot 25 during the teaching operation, and rz is the rotation angle of the camera 31 around the z-axis that is perpendicular to the x-axis and y-axis. t axis,y t The axis, x-axis, and y-axis are set in a horizontal plane (the same applies to the x'-axis and y'-axis described below).

[0057] Next, the correction amount calculation unit 50 similarly analyzes the current image and calculates the coordinate system (x t axis-y t Based on the coordinate system (x-axis-y-axis coordinate system), the current position (x curr,y curr ,rz curr ) is calculated.

[0058] Then, the correction amount calculation unit 50 estimates the position error amounts Δx, Δy and rotation error amount Δrz between the position of the camera 31 during the teaching operation and the current position in the xy coordinate system using the following formulas 1 to 3. (Equation 1) TIFF0007797558000001.tif15133(Formula 2) TIFF0007797558000002.tif15133(Formula 3) TIFF0007797558000003.tif15133

[0059] Here, as shown in FIG. 7, the current coordinate system of the robot 25 is the x'-y' coordinate system, and as shown in FIG. 8, there is a distance t x ,t y Assuming that there is a translation error, the current position (x', y') of the camera 31 in the x'-y' coordinate system is calculated by the following formula 4. Note that x and y in the formula below respectively represent the position (x teach ,y teach ), which is known as the default value. (Equation 4) TIFF0007797558000004.tif18133

[0060] Then, the translation error t is calculated by the following equation 5, which is a transformation of the above equation 4. x ,t y The correction amount calculation unit 50 calculates the translation error amount t x ,t y Calculate the translation error t x ,t y The rotation error amount Δrz is set as the correction amount in the working posture. (Equation 5) TIFF0007797558000005.tif20133 However, the current position (x', y') of the camera 31 in the x'-y' coordinate system coincides with the current position (x+Δx, y+Δy) of the camera 31 in the x-y coordinate system.

[0061] The automatic operation control unit 47 then corrects the position of the hand 29 of the robot 25 based on the correction amount calculated by the correction amount calculation unit 50 for the working postures when the robot 25 works on the machine tool 10, for example, the removal preparation posture, gripping posture and removal posture in the workpiece removal operation posture, and the attachment preparation posture, attachment posture and separation posture in the workpiece attachment operation posture.

[0062] For example, when positioning the hand 29 of the robot 25 relative to the chuck 12, the positioning position of the hand 29 in the x'-y' coordinate system, which is the current coordinate system of the robot 25, is corrected so that it matches the positioning position of the hand 29 in the x'-y' coordinate system set during the teaching operation.

[0063] This correction is shown in Figure 9. In Figure 9, the position xp p ,yp p , and position xp c ,yp c is the set position of the hand 29 in the x-axis-y-axis coordinate system, which is the robot coordinate system during teaching operation, and the hand 29 is at the position xp p ,yp p Position xp set for chuck 12 from c ,yp c If there is no positional deviation between the automated guided vehicle 35 and the robot 25 positioned at the work position, the hand 29 will be positioned at the position xp p ,yp p From position xp c ,yp c Go to.

[0064] In Figure 9, position xp' p ,yp'p is the position of the hand 29 in the imaging posture in the x'-y' coordinate system, which is the robot coordinate system during the current operation. p ,yp' p Since the automatic guided vehicle 35 and the robot 25 positioned at the work position are misaligned, the position xp p ,yp p In the x'-y' coordinate system, the position error Δx, Δy and the rotation error Δrz are generated. p ,yp p In this x'-y' coordinate system, the position xp c ,yp c The corresponding position is xp' c ,yp' c However, this position is shifted from the true position of the chuck 12. Therefore, the automatic operation control unit 47 c ,yp c is calculated by the correction amount calculation unit 50. x ,t y and xph' corrected according to the following formula 6 based on the rotation error amount Δrz: c ,yph' c and calculate the corrected position xph' c ,yph' c The hand 29 is moved in the Z-axis direction. The rotational posture of the hand 29 around the Z-axis is corrected based on the rotation error amount Δrz. (Equation 6) TIFF0007797558000006.tif24133

[0065] Furthermore, this position data xph' c ,yph' c is converted into angle data for each joint of the robot 25 by a preset conversion formula, and the robot 25 is controlled in accordance with the converted angle data.

[0066] Then, each position xp of the hand 29 set during the teaching operation as each working posture when the robot 25 works on the machine tool 10 is i ,ypi The corrected position xph' corresponding to i ,yph' i can be calculated by the following Equation 7, which is a generalization of Equation 6 above. The automatic operation control unit 47 corrects the rotational posture of the hand 29 around the Z axis based on the rotation error amount Δrz, and calculates each corrected position xph' i ,yph' i Move hand 29 to i, where i is a natural number equal to or greater than 1. (Equation 7) TIFF0007797558000007.tif22133

[0067] According to the system 1 of this example having the above configuration, unmanned automatic production is carried out as follows.

[0068] That is, under the control of the automatic driving control unit 47 of the control device 40, the automatic driving program stored in the operation program memory unit 41 is executed, and in accordance with this automatic driving program, for example, the unmanned guided vehicle 35 and the robot 25 operate as follows.

[0069] First, the automated guided vehicle 35 moves to a work position set for the machine tool 10, and the robot 25 assumes the work start posture for the workpiece removal operation described above. At this time, it is assumed that the machine tool 10 has completed the specified machining, has opened the door cover to allow the robot 25 to enter the machining area, and has received a command from the automatic operation control unit 47 to advance the support bar 15 of the tool presetter 13 into the machining area.

[0070] Next, the robot 25 moves to the imaging posture, and the camera 31 images the identification graphic attached to the support bar 15. When the identification graphic is imaged by the camera 31 in this manner, the correction amount calculation unit 50 estimates the position error amounts Δx, Δy and rotation error amount Δrz between the imaging posture at the time of the teaching operation of the robot 25 and the current imaging posture according to the above-mentioned formula 1-3, based on the image of the identification graphic and the reference image stored in the reference image storage unit 45, and calculates the translation error correction amount t for the subsequent workpiece removal operation posture of the robot 25 according to the above-mentioned formula 4-5 based on each estimated error amount. x ,t y And the rotation error correction amount Δrz is calculated.

[0071] Then, based on each correction amount calculated by the correction amount calculation unit 50, the automatic operation control unit 47 corrects the position of the hand 29 in the subsequent workpiece removal operation postures, i.e., the above-mentioned removal preparation posture, gripping posture, removal posture and work completion posture, according to Equation 7, and also corrects the rotational position around the Z axis, so that the machined workpiece W' gripped in the chuck 12 of the machine tool 10 is gripped by the hand 29 and removed from the machine tool 10. After the robot 25 is caused to take the above-mentioned gripping posture, the automatic operation control unit 47 sends a chuck open command to the machine tool 10, whereby the chuck 12 is opened.

[0072] Next, the automatic driving control unit 47 moves the unmanned transport vehicle 35 to a work position set for the product stocker 21, and causes the robot 25 to sequentially assume a storage start posture when starting work in the product stocker 21, various storage postures for storing the machined workpiece held by the hand 29 in the product stocker 21, and a storage completion posture when storage is complete, thereby storing the machined workpiece held by the hand 29 in the product stocker 21.

[0073] Next, the automatic driving control unit 47 moves the unmanned transport vehicle 35 to a work position set for the material stocker 20, and causes the robot 25 to sequentially assume an unloading start posture when work begins at the material stocker 20, various unloading postures for grasping the pre-machined work stored in the material stocker 20 with the hand 29 and unloading it from the material stocker 20, and an unloading completion posture when unloading is completed, and causes the hand 29 to grasp the pre-machined work.

[0074] Next, the automatic operation control unit 47 again moves the automated guided vehicle 35 to the work position set with respect to the machine tool 10, and causes the robot 25 to assume the work start posture for the workpiece mounting operation described above. Next, the robot 25 is moved to the imaging posture, and the identification figure provided on the support bar 15 is imaged by the camera 31. When the identification figure is imaged by the camera 31 in this manner, the correction amount calculation unit 50 estimates the position error amounts Δx, Δy and rotation error amount Δrz between the imaging posture at the time of the teaching operation of the robot 25 and the current imaging posture according to the above-mentioned formulas 1-3, based on the image of the identification figure and the reference image stored in the reference image storage unit 45, and calculates the translation error correction amount t for the subsequent workpiece mounting operation posture of the robot 25 according to the above-mentioned formulas 4-5 based on each estimated error amount. x ,t y And the rotation error correction amount Δrz is calculated.

[0075] Thereafter, the automatic operation control unit 47 corrects the position of the hand 29 in the subsequent workpiece mounting operation postures of the robot 25, i.e., the above-mentioned mounting preparation posture, mounting posture, separation posture, and work completion posture, according to Equation 7 based on the respective correction amounts calculated by the correction amount calculation unit 50, and corrects the rotational position about the Z axis, causing the robot 25 to mount the unmachined workpiece W held by the hand 29 in the chuck 12 of the machine tool 10 and then retract to the outside of the machine. Thereafter, the automatic operation control unit 47 sends a machining start command to the machine tool 10 to cause the machine tool 10 to perform a machining operation. After the robot 25 has been caused to assume the mounting posture, the automatic operation control unit 47 sends a chuck close command to the machine tool 10, which closes the chuck 12 and causes the chuck 12 to grip the unmachined workpiece W.

[0076] By repeating the above process, unmanned automatic production is continuously carried out in the system 1 of this example.

[0077] In the system 1 of this example, the working posture of the robot 25 is corrected using an identification figure placed within the machining area of ​​the machine tool 10 where the robot 25 actually works, so that the working posture can be corrected accurately, and as a result, the robot 25 can perform the work with high precision even when the work requires high operating accuracy.

[0078] Furthermore, since the robot 25 performs the work with high precision in this way, the system 1 operates at a high availability rate without unnecessary interruptions, and as a result, the system 1 makes it possible to achieve unmanned operation with high reliability and high production efficiency.

[0079] Furthermore, the robot 25, which operates according to an operating program, is configured to capture an image of the identification figure with the camera 31 in one operation, so that correction can be performed with high accuracy in a short time compared to conventional methods.

[0080] Furthermore, in this example, when the machine tool 10 is performing machining, an identification figure is provided on the support bar 15 of the tool presetter 13, which is stored outside the machining area, so that the identification figure can be prevented from being soiled or damaged by chips and the like generated during machining, and as a result, the above-mentioned correction can be performed with high precision.

[0081] Furthermore, in this example, the identification figure has a matrix structure in which a plurality of pixels are arranged two-dimensionally, so that the positional error amounts Δx, Δy and rotational error amount Δrz can be estimated with high accuracy and high repeatability.

[0082] (Second embodiment) Next, a second embodiment of the present invention will be described. The configuration of the system of this example is indicated by the reference numeral 1' in FIG. 2. As shown in FIG. 2, the system 1' of this example differs from the system 1 of the first embodiment in that a correction amount calculation unit 50' in a control device 40' is different from that of the system 1 of the first embodiment, but the other configurations are the same as those of the system 1 of the first embodiment. Therefore, hereinafter, a description of the configuration other than the correction amount calculation unit 50' will be omitted. Note that in this example, as in the first embodiment, it is preferable to have the camera 31 directly facing the identification figure in the imaging posture of the robot 25, as this allows for more accurate correction. However, practical correction can also be performed even if the imaging optical axis of the camera 31 is inclined obliquely with respect to the identification figure without facing directly.

[0083] The correction amount calculation unit 50' in this example calculates the position error amount and rotation error amount of the camera 31 between the current posture of the robot 25 and the posture at the time of the teaching operation by a generalized method of calculating the error amount in the correction amount calculation unit 50, and corrects each working posture of the robot 25 based on the obtained position error amount and rotation error amount.

[0084] Specifically, the correction amount calculation unit 50' executes the following processing based on the image of the current identification figure obtained during automatic operation and the reference image (image captured during the teaching operation) stored in the reference image memory unit 45, etc., to estimate the position error amount of the camera 31 between the current posture of the robot 25 and the posture at the time of the teaching operation, which includes the position error amount of the camera 31 in the mutually perpendicular x-axis and y-axis set in a plane parallel to the identification figure, and in the z-axis direction perpendicular to these x-axis and y-axis, and the rotation error amount of the camera 31 around the x-axis, y-axis and z-axis, and corrects each working posture of the robot 25 based on the estimated position error amount and rotation error amount.

[0085] (Pretreatment) As a pre-processing step, the correction amount calculation unit 50' first calculates a coordinate transformation matrix (math) for transforming a camera coordinate system, which is a coordinate system corresponding to the camera 31, into a graphic coordinate system, which is a coordinate system for the identification graphic, based on the reference image captured during the teaching operation. Get TIFF0007797558000008.tif612. Note that this coordinate transformation matrix TIFF0007797558000009.tif612 can be acquired from the internal parameters of the camera 31, the homography matrix recognized from the identification figure, the center coordinates, the corner coordinates, the size of the identification figure, and the like.

[0086] The camera coordinate system is a three-dimensional coordinate system set for the planar imaging element group of the camera, with the origin set at the center of the imaging element group, for example. The graphic coordinate system is a three-dimensional coordinate system set for the identification graphic, with the origin set at the center of the identification graphic, for example. The robot coordinate system, which will be described later, is a three-dimensional coordinate system set for the control device 40' to control the robot 25, with the origin set at an appropriate position.

[0087] Next, the correction amount calculation unit 50' calculates the obtained coordinate transformation matrix TIFF0007797558000010.tif612, and the camera position in the camera coordinate system, which is the camera position at the time of capturing an image in the teaching operation. TIFF0007797558000011.tif611, the camera position during teaching operation in the graphic coordinate system TIFF0007797558000012.tif611 is calculated using the following formula 8. (Equation 8) TIFF0007797558000013.tif22133

[0088] (Camera position calculation process during teaching operation) Next, the correction amount calculation unit 50' calculates the camera position in the robot coordinate system during the teaching operation. TIFF0007797558000014.tif611 is calculated using the following formula 9. (Equation 9) TIFF0007797558000015.tif18159 Next, the correction amount calculation unit 50' calculates a coordinate transformation matrix for transforming from the camera coordinate system during teaching operation to the robot coordinate system during teaching operation. TIFF0007797558000016.tif612 is calculated using the following formula 10. (Equation 10) TIFF0007797558000017.tif21124 where, Rotation matrix components of TIFF0007797558000018.tif411 Based on TIFF0007797558000019.tif411, rotation angles around the x-axis, y-axis, and z-axis TIFF0007797558000020.tif411, TIFF0007797558000021.tif411, Calculate TIFF0007797558000022.tif411. still, TIFF0007797558000023.tif66 is a coordinate transformation matrix used to convert from the geometric coordinate system to the robot coordinate system during teaching operations. For example, the coordinate transformation matrix used to convert from the geometric coordinate system to the camera coordinate system during teaching operations. TIFF0007797558000024.tif612 and the coordinate transformation matrix for converting from the camera coordinate system to the robot coordinate system during teaching operation Based on TIFF0007797558000025.tif612, it can be obtained by the following formula 11. (Equation 11) TIFF0007797558000026.tif15124

[0089] (Camera position calculation process during autonomous driving) Next, the correction amount calculation unit 50' calculates a coordinate transformation matrix for transforming from the camera coordinate system to the graphic coordinate system in the same manner as described above, based on the image of the current identification graphic obtained during automatic driving (actual operation). After acquiring TIFF0007797558000027.tif611, the current camera position in the geometry coordinate system is calculated based on the current image. TIFF0007797558000028.tif610 is calculated using the following formula 12, and the current camera position in the robot coordinate system during the teaching operation is calculated using the formula 12. TIFF0007797558000029.tif410 is calculated using the following formula 13. (Equation 12) TIFF0007797558000030.tif20124(Formula 13) TIFF0007797558000031.tif17151 Next, the correction amount calculation unit 50' calculates a coordinate transformation matrix for transforming the current camera coordinate system into the robot coordinate system during teaching operation. TIFF0007797558000032.tif411 is calculated using the following formula 14. (Equation 14) TIFF0007797558000033.tif25120 where, Rotation matrix components of TIFF0007797558000034.tif411 Based on TIFF0007797558000035.tif411, rotation angles around the x-axis, y-axis, and z-axis TIFF0007797558000036.tif411, TIFF0007797558000037.tif411, Calculate TIFF0007797558000038.tif411.

[0090] (Error amount calculation process) Next, the correction amount calculation unit 50' calculates the camera angle at the time of the teaching operation in the coordinate system at the time of the teaching operation calculated as described above. TIFF0007797558000039.tif612, TIFF0007797558000040.tif612, TIFF0007797558000041.tif612 and the current camera angle in the coordinate system during teaching operation TIFF0007797558000042.tif411, TIFF0007797558000043.tif411, TIFF0007797558000044.tif411, and by calculating the differences between them, the rotation errors Δrx, Δry, and Δrz around the x-axis, y-axis, and z-axis are calculated. however, TIFF0007797558000045.tif55117

[0091] Next, the correction amount calculation unit 50' calculates the rotation matrix between the robot coordinate system during the teaching operation and the current robot coordinate system based on the rotation errors Δrx, Δry, and Δrz calculated as described above. TIFF0007797558000046.tif45, that is, the amount of rotation error is calculated using the following formula 15, and the translation matrix from the robot coordinate system during teaching operation to the current robot coordinate system is calculated using the following formula 15. TIFF0007797558000047.tif45, that is, the amount of position error is calculated by the following Equation 16. (Equation 15) TIFF0007797558000048.tif22146(Formula 16) TIFF0007797558000049.tif16133

[0092] (Correction amount calculation process) Next, the correction amount calculation unit 50' calculates a correction amount for correcting the amount of error based on the amount of error calculated as described above. TIFF0007797558000050.tif46 is calculated using the following formula 17. (Equation 17) TIFF0007797558000051.tif22133

[0093] Then, the automatic operation control unit 47 calculates the position of the hand 29 in the subsequent operating posture of the robot 25 based on the correction amount calculated by the correction amount calculation unit 50'. TIFF0007797558000052.tif65 is corrected according to the following formula 18. (Equation 18) TIFF0007797558000053.tif24133

[0094] (Third embodiment) The configuration of the system of this example is shown in FIG. 2 and is designated by the symbol 1″. As shown in FIG. 2, the system 1″ of this example differs from the system 1 of the first and second embodiments in the correction amount calculation unit 50″ and the operation program storage unit 41″ that constitute the control device 40″, but the other configuration is the same as the system 1 of the first and second embodiments. Therefore, in the following, explanations of the configuration other than the correction amount calculation unit 50″ and the operation program storage unit 41″ will be omitted.

[0095] An automatic operation program different from that of the first and second embodiments is stored in operation program storage unit 41" of this example. This automatic operation program differs from that of the first and second embodiments in that, among the operations of robot 25 performing work on machine tool 10, the operation of capturing an image of the identification graphic is executed twice in succession. That is, the automatic operation program of this example is set to execute a first imaging operation for calculating the amount of positional error in the x-axis and y-axis directions and the amount of rotational error about the z-axis, and a second imaging operation for calculating the amount of positional error in the z-axis direction and the amount of rotational error about the x-axis and y-axis, with the imaging posture of robot 25 corrected based on the calculated amount of positional error and amount of rotational error.

[0096] The correction amount calculation unit 50'' executes the ``pre-processing'' and ``camera position calculation processing during teaching operation'' in the correction amount calculation unit 50' according to the second embodiment, and also executes processing to calculate the correction amount based on each of the images obtained by the first imaging operation and the second imaging operation executed under the control of the automatic driving control unit 47.

[0097] (First correction amount calculation process) The correction amount calculation unit 50'' executes the ``pre-processing,'' ``camera position calculation processing during teaching operation,'' ``camera position calculation processing during automatic driving,'' ``error amount calculation processing,'' and ``correction amount calculation processing'' in the correction amount calculation unit 50' based on the first captured image, to calculate the position error amounts in the x-axis and y-axis directions and the rotation error amount around the z-axis, and also calculates correction amounts for correcting these error amounts.

[0098] In this case, the camera positions in the graphic coordinate system and each camera position in the robot coordinate system are subjected to the "pre-processing," "camera position calculation processing during teaching operation," "camera position calculation processing during automatic driving," "error amount calculation processing," and "correction amount calculation processing," respectively, as follows. TIFF0007797558000054.tif49170

[0099] Through the above processing, only the position error amount Δx in the x-axis direction, the position error amount Δy in the y-axis direction, and the rotation error amount Δrz around the z-axis are obtained, and the correction amount for correcting these is calculated using the above formula 17. Then, the automatic driving control unit 47 corrects the posture of the robot 25 taken in the second image capture in accordance with the above formula 18.

[0100] (Second correction amount calculation process) Next, the correction amount calculation unit 50'' executes the ``pre-processing,'' ``camera position calculation processing during teaching operation,'' ``camera position calculation processing during automatic driving,'' ``error amount calculation processing,'' and ``correction amount calculation processing'' based on the second captured image to calculate the position error amounts in the x-axis, y-axis, and z-axis directions, and the rotation error amounts around the x-axis, y-axis, and z-axis, and also calculates correction amounts for correcting these error amounts.

[0101] In this case, the camera positions during teaching operations in the graphic coordinate system and the camera positions in the robot coordinate system are respectively set as follows: "pre-processing," "camera position calculation processing during teaching operations," "camera position calculation processing during automatic driving," "error amount calculation processing," and "correction amount calculation processing." TIFF0007797558000055.tif54170

[0102] Through the above processing, the position error amount Δx in the x-axis direction, the position error amount Δy in the y-axis direction, the position error amount Δz in the z-axis direction, the rotation error amount Δrx about the x-axis, the rotation error amount Δry about the y-axis, and the rotation error amount Δrz about the z-axis are obtained, and the correction amounts for correcting these are calculated using the above-mentioned Equation 17. Then, the automatic driving control unit 47 corrects the posture of the robot 25 according to the above-mentioned Equation 18. Note that the correction amounts for the position error amount Δx in the x-axis direction, the position error amount Δy in the y-axis direction, and the rotation error amount Δrz about the z-axis may be the same as the values ​​calculated the first time, or may be replaced by a value obtained by adding the values ​​calculated the first time and the values ​​calculated the second time.

[0103] The reason for calculating the correction amount in two stages as described above is that when capturing an image of an identification figure, if the identification figure is located far from its center position within the field of view of camera 31, the variation in position data in the z-axis direction obtained from the figure coordinate system, the variation in rotation data around the x-axis, and the variation in rotation data around the y-axis tend to increase, which could result in a deterioration in positional accuracy in the x-axis and y-axis directions.

[0104] Therefore, as described above, in the first correction amount calculation process, correction amounts for correcting the positional error amounts in the x-axis and y-axis directions and the rotational error amount Δrz about the z-axis are calculated, and the captured posture of the robot 25 is corrected based on these correction amounts so that the identification figure is positioned at the center of the field of view of the camera 31. Then, in the second correction amount calculation process, correction amounts for the remaining positional error amount in the z-axis direction and the rotational error amounts Δrx, Δry about the x-axis and y-axis are calculated based on the image in which the identification figure is positioned at the center of the field of view of the camera 31. As a result, accurate positional error amounts in the x-axis, y-axis, and z-axis directions and rotational error amounts Δrx, Δry, Δrz about the x-axis, y-axis, and z-axis can be calculated, and accurate correction amounts for these error amounts can be calculated. As a result, the posture of the robot 25 can be controlled with high precision.

[0105] (Fourth embodiment) In the embodiments described above, the position error amounts Δx, Δy and rotation error amount Δrz are calculated to correct the posture of the robot-mounted moving device, but this is not limiting. A configuration may also be adopted in which the target position of a target, such as a workpiece, is acquired based on a first identification position, which is the position of a reference identification figure, and a second identification position, which is the position of an identification figure calculated from an image including the identification figure captured by a camera to confirm the position before performing work, and the position of the robot hand is corrected. In other words, a configuration may also be adopted in which the target position is acquired directly without calculating the position error amounts Δx, Δy and rotation error amount Δrz.

[0106] Furthermore, in the above embodiments, the attachment and detachment of a workpiece has been mainly described as an example, but the present invention is not limited to this. In addition to workpieces, the objects include tools, ATC cameras, measuring instruments, etc. The objects are those that are attached and detached to and used within machine tools. This is because these objects can be transported by a robot-mounted transfer device.

[0107] Therefore, first, the robot-mounted mobile device memorizes the position of the identification figure arranged in the machine tool along a first axis and a second axis set in a plane parallel to the identification figure (for example, position coordinates based on two axes in the plane) by teaching. The first identification position is information associated with the first device position as the position of the robot-mounted mobile device when performing an operation to remove an object such as a workpiece, tool, ATC camera, or measuring instrument from the machine tool, or an operation to install an object such as a workpiece, tool, ATC camera, or measuring instrument in the machine tool. Here, the first and second axes only need to intersect and do not need to be orthogonal. Any axes that can provide information that allows the position (coordinates) to be identified in the plane will suffice. Of course, a relationship between the x-axis and y-axis that are orthogonal is preferred. Furthermore, the first device position of the robot-mounted mobile device in this embodiment is position information that also includes position changes such as rotation.

[0108] The first identified position is associated with a target position, which is the position of the target. The target position may be position information of the target itself, such as the position of a tool or the position of a workpiece, or may be position information of an installation position or removal position, such as the workpiece mounting position of a spindle on which a workpiece is mounted, or the tool mounting position of a spindle or tool rest on which a tool is mounted.

[0109] For example, the robot-mounted transfer device moves from in front of another second machine tool, moves in front of the first machine tool on which the workpiece is to be placed, and stops in front of the first machine tool. The position where the robot-mounted transfer device stops becomes the second device position. If this second device position is the same as the first device position, the workpiece can be placed without any correction. In the robot-mounted transfer device of this embodiment, the stop position after movement and stopping may differ from the first device position. In such cases, the workpiece placement position when viewed from the second device position as a reference also changes, so the hand position must be corrected.

[0110] Therefore, the robot-mounted mobile device takes an image with a camera at the second device position. If an identification graphic is present in the image taken by the camera of the robot-mounted mobile device, the robot-mounted mobile device acquires a second identification position of the identification graphic at the second device position. The robot-mounted mobile device acquires information about the target position at the second device position using the stored first identification position and the second identification position acquired by the camera image. Then, based on the information about the target position, the robot-mounted mobile device corrects the position of the robot's hand unit by (a) movement on the first axis, (b) movement on the second axis, and (c) rotational movement within the plane including the identification graphic, and places the workpiece held by the hand unit at a predetermined position within the machine tool.

[0111] Here, for example, if the first device position is considered to be the origin, and the first axis is the X1 axis and the second axis is the Y1 axis, the first identified position will be (x1, y1, rz1). The first identified position is associated with the target position (x11, y11, rz11), which is the target position. If the second device position is considered to be the origin, and the first axis is the X2 axis and the second axis is the Y2 axis, the second identified position will be (x2, y2, rz2). If the first device position and the second device position are the same, (x2, y2, rz2) and (x1, y1, rz1) will be the same position. Therefore, the target position when viewed from the second device position as the reference will also be the same as the (x11, y11, rz11) position information.

[0112] However, as mentioned above, since the robot-mounted mobile device moves between machine tools, the first device position and the second device position may differ. Here, we will explain the case where the first identification position is (x1, y1, 0 (rz1 = 0)) and the target position is (x11, y11, rz11). In this case, if the second device position is considered to be the origin, and the first axis is the X2 axis and the second axis is the Y2 axis, the second identification position will no longer be (x2, y2, 0). This is because the first identification position and the second identification position are the same position in real space, but the positions of the robot-mounted mobile device (especially the mobile unit of the robot-mounted mobile device) are different. In particular, this is because the orientation of the mobile unit is different.

[0113] Therefore, in this embodiment, the target position (x22, y22, rz22) is acquired using a matrix that converts the relationship between (i) the second identification position (x2, y2, rz2) when the first axis is the X2 axis and the second axis is the Y2 axis and (ii) the first identification position (x1, Y1, 0) into position information of the target position, which is the target position in the X2-Y2 coordinate system of the X2 and Y2 axes. The conversion matrix is ​​created in advance and stored in the robot-mounted moving device. Based on the acquired position information of the target position (x22, y22, rz22) on the X2 and Y2 axes, the control unit corrects the position of the robot hand unit by (a) movement on the X2 axis, (b) movement on the Y2 axis, and (c) rotational movement within the plane including the identification figure, and controls the hand unit to perform operations such as changing a workpiece or tool.

[0114] In this embodiment, the robot-mounted moving device stores in advance a matrix that converts the target position (x22, y22, rz22) into position information, and acquires the target position using this matrix, but this is not limited to this. For example, a table describing the position information (x2, y2, rz2) that is the position of the identification figure obtained from an image captured by a camera, and the position information (x22, y22, rz22) that is the target position associated with that position information (second identification position) may be stored in advance in the robot-mounted positioning device.

[0115] Furthermore, in this embodiment, the hand position is corrected without calculating the three position error amounts Δx, Δy, and rotation error amount Δrz. However, a configuration is also possible in which the rotation error amount Δrz is calculated without calculating the position error amounts Δx and Δy. For example, the X coordinate (x22) and Y coordinate (y22) and rotation error amount Δrz of an object such as a workpiece at the second device position are calculated using the first identified position, the second identified position, and a transformation matrix. Then, the rotation error amount Δrz may be added to the rotation position (rz11) of the object position at the first identified position to obtain the object position (x22, y22, rz11 + Δrz).

[0116] The position information in this embodiment uses position information (x, y, rz), which is three pieces of information: x coordinate, y coordinate, and rotation coordinate (or rotation amount), but is not limited to this. For example, six pieces of information (x, y, z, rx, ry, rz), consisting of three coordinates (x, y, z) and three rotation coordinates or rotation amounts (rx, ry, rz), may be used. The number of pieces of information can be appropriately selected or adjusted as needed. For example, the target position may be output or acquired as (i) position information (x22, y22, z11, rx11, ry11, rz11 + Δrz) or (ii) position information (x22, y22, z11, 0, 0, rz11 + Δrz). In the example of position information (x22, y22, z11, 0, 0, rz11 + Δrz), z11 is left out because the position is on the z axis. If the reference is set to 0, then rx11 and ry11 will be 0, and since they do not change when moving within a plane, they will not change from 0. For this reason, they can be set to 0. This type of position information can be used, or alternatively, the 0 information can be deleted and the position information of the four pieces of information (x22, y22, z11, rz11 + Δrz) can be output or acquired as the target position.

[0117] Although various modified examples have been described, as explained in each embodiment, the hand position is corrected within the plane (x, y, rz) including the identification figure, and therefore the common effect is that the hand position can be corrected with high precision within the plane including the identification figure.

[0118] Although one embodiment of the present invention has been described above, the specific aspects that the present invention can adopt are not limited to this in any way.

[0119] For example, in each of the above-described embodiments, the identification figure has a matrix structure in which multiple pixels are arranged two-dimensionally, but this is not limited to this, and various figures can be used as long as they can calculate the amount of correction for the posture of the robot 25 from the captured image.

[0120] In the first embodiment, the first and second axes in a plane including the identification figure are defined as the x-axis and the y-axis, respectively, and the rotational error around the z-axis is corrected. However, this is not limited to this. Depending on the position of the identification figure, the correction amount calculation unit 50 may use the z-axis as the first or second axis. In this case, the correction amount calculation unit 50 may be configured to estimate the position error in the z-axis direction and calculate the corresponding correction amount. Furthermore, the automatic driving control unit 47 may be configured to correct the z-axis position of the robot 25 in each working posture based on the calculated z-axis correction amount. The z-axis position error amount can also be calculated, for example, from the magnification ratio between the basic image size and the current image size.

[0121] Furthermore, in each of the above embodiments, an example has been given in which an automated guided vehicle 35 is used, but the present invention is not limited to this. A transport device that can be moved by being pushed by a person, like a general cart, may also be used. A configuration may also be adopted in which a robot 25 is mounted on this transport device, the transport device is manually transported to the work position of the machine tool 10, and the robot 25 is used to attach and detach a workpiece to and from the machine tool 10.

[0122] Furthermore, in each of the above embodiments, a vertical lathe is used as an example of a machine tool, but this is not limited to this, and any previously known machine tool can be applied, such as a horizontal lathe, vertical and horizontal machining centers, and a multi-machining machine equipped with a tool spindle and a work spindle.

[0123] For example, in the case of a horizontal lathe 100 equipped with a tool spindle 105 for rotating a tool, as shown in FIG. 10, the display panel 16 can be supported horizontally by a holder 106, and the holder 106 can be attached to the tool spindle 105. In this case, when machining is performed by the lathe 100, the holder 106 is stored in a tool magazine, which is a tool storage section, and when work is performed by the robot 25, the holder 106 is removed from the tool magazine and attached to the tool spindle 105. In FIG. 10, reference numeral 101 denotes a first spindle, reference numeral 103 denotes a second spindle, and these are arranged coaxially and facing each other. Reference numeral 102 denotes a first chuck attached to the first spindle 101, and reference numeral 104 denotes a second chuck attached to the second spindle 103. Further, reference numeral 107 denotes a tool rest, reference numeral 108 denotes a turret provided on the tool rest 107, and reference numeral 109 denotes a support jig that supports the workpiece W″ and is attached to the outer surface of the turret 108.

[0124] In the above embodiments, the x-axis and y-axis (x'-axis and y'-axis) of the robot coordinate system are set in a horizontal plane, and the z-axis is set in a vertical direction, but this is not limitative and the directions of the coordinate axes can be set arbitrarily. t axis,y t The same is true for the axes.

[0125] To reiterate, the above-described embodiments are illustrative in all respects and are not limiting. Variations and modifications are possible for those skilled in the art. The scope of the present invention is defined by the claims, not the above-described embodiments. Furthermore, the scope of the present invention includes modifications from the embodiments within the scope of the claims and their equivalents.

Claims

1. A method for controlling the operation of a robot-mounted moving device that is provided so as to be movable around a machine tool, the robot having (i) a camera, (ii) a hand unit, (iii) a second arm unit that movably connects the hand unit, and (iv) a first arm unit that movably connects the second arm unit, and a moving unit on which the robot is mounted and is movable, the method comprising: As related information relating to a first device position as the position of the robot-mounted moving device when working inside the machine tool, an identification figure arranged corresponding to the machine tool, the identification figure having a matrix structure in which a plurality of square pixels are arranged two-dimensionally, is photographed with the camera, and the position of the identification figure at the first device position along a first axis and a second axis set in a plane parallel to the identification figure is obtained as a first identification position; Calculating coordinates of the X-axis position, Y-axis position, and Z-axis position of the hand unit from the identification figure in order to transport the workpiece, have it gripped by the machine tool, and process the workpiece with the machine tool; A control method in which the position of the hand unit is controlled to allow the machine tool to grip a workpiece based on the calculated X-axis position, Y-axis position, and Z-axis position.

2. A robot-mounted mobile device capable of moving around the machine tool, wherein as related information relating to a first device position as a position of the robot-mounted mobile device when working on a machine tool, an identification graphic is arranged corresponding to the machine tool, the identification graphic having a matrix structure in which a plurality of square pixels are two-dimensionally arranged, and the position of the identification graphic at the first device position along a first axis and a second axis set in a plane parallel to the identification graphic is stored as a first identification position, a robot having (i) a camera, (ii) a hand unit, (iii) a second arm unit movably connecting the hand unit, and (iv) a first arm unit movably connecting the second arm unit; a control unit for controlling the position of a hand unit of the robot; a moving unit on which the robot is mounted and which is movable, The control unit calculates coordinates of the X-axis position, Y-axis position, and Z-axis position, which are the position of the hand unit, from the identification graphic in order to transport the workpiece, have the machine tool grasp it, and process the workpiece with the machine tool, and controls the position of the hand unit based on the X-axis position, Y-axis position, and Z-axis position in order to have the machine tool grasp the workpiece.

Images