WO2022195938A1

WO2022195938A1 - Robot system positioning accuracy measurement method

Info

Publication number: WO2022195938A1
Application number: PCT/JP2021/037694
Authority: WO
Inventors: 秀樹長末
Original assignee: Dmg森精機株式会社
Priority date: 2021-03-15
Filing date: 2021-10-12
Publication date: 2022-09-22
Also published as: JP6937444B1; JP2022141188A

Abstract

According to the present invention, an identification figure (111) is disposed on one of a moving body (105) or a tip of a robot of a machine tool, and a camera is disposed on the other of the moving body (105) or the tip of the robot. The moving body (105) and the tip of the robot are positioned at a first position, the identification figure (111) is imaged by the camera, and on the basis of the image, the relative positions of the camera and the identification figure (111) at the first position are calculated. Next, at least one of the robot and an automatic guided vehicle is operated to position the tip of the robot at a predetermined second position and move the moving body (105) in the same direction by the same distance to image the identification figure (111). Next, on the basis of the obtained image, the relative positions of the camera and the identification figure (111) at the second position are calculated, and on the basis of the relative positions of the camera and the identification figure at the first position and the second position, the positioning accuracy of the tip of the robot is calculated.

Description

Robot system positioning accuracy measurement method

The present invention relates to a robot that performs work on a machine tool, an automatic guided vehicle equipped with this robot and passing through a work position set with respect to the machine tool, and a control that controls the operation of these robots and the automatic guided vehicle. The present invention relates to a method for measuring the positioning accuracy of a robot tip in a robot system composed of devices.

Conventionally, a self-propelled robot disclosed in International Publication No. 2018/92222 (Patent Document 1 below) is known as an example of the above-described robot system. This self-propelled robot consists of an unmanned guided vehicle and a manipulator with 3 or more degrees of freedom provided on the unmanned guided vehicle. , moves to the vicinity of the target position while recognizing its own approximate position, and then recognizes the target or the marker attached to the target by the camera, thereby performing precise positioning.

Then, this self-propelled robot receives work requests related to transport work for transporting objects to be transported and maintenance work such as disposal of chips, replacement of tools, and lubrication, which are transmitted from a plurality of machine tools. to the requesting machine tool.

WO2018/92222

By the way, the manipulator (robot) described above has a structure in which a plurality of arms (links) are connected by joints so that they are continuous, and the positioning error of the hand (end effector) provided at the tip is , is governed by the rotational accuracy of each joint, and the motion error of each joint is accumulated. For this reason, for example, when motion errors of the joints become large due to deterioration over time, etc., these are accumulated, resulting in a large positioning error of the hand, and as a result, the motion accuracy of the robot deteriorates.

In addition, the above-mentioned unmanned guided vehicle is configured to move on wheels, and conventionally, these wheels are made of resin. For this reason, when the automatic guided vehicle operates for a long period of time, the wheels wear, and when the wheels wear like this, the positioning accuracy of the automatic guided vehicle deteriorates. positioning accuracy of the hand is deteriorated.

Then, as described above, when the positioning accuracy of the robot's hand deteriorates, an error occurs in the operation planned for the robot system, and the operation is not completed.

Therefore, in order to ensure that the positioning accuracy of the hand in the robot system is within the allowable range, for example, the positioning accuracy is periodically measured, and when the positioning accuracy is outside the allowable range, the robot It is necessary to perform maintenance work such as replacement of parts that make up the joints and replacement of the wheels of the automatic guided vehicle.

Conventionally, however, measuring the positioning accuracy of the hand requires a dedicated special measuring device, and such a measuring device is generally expensive. It was impractical and difficult to prepare a bulky and expensive measuring device.

The present invention has been made in view of the above circumstances, and its object is to provide a measuring method capable of measuring the positioning accuracy of the tip of the robot in the robot system without using a special measuring device.

The present invention for solving the above problems is a robot having an end effector at its distal end and using the end effector to perform work on a machine tool;
an automatic guided vehicle equipped with the robot and passing through a work position set for the machine tool;
A control device that controls the automatic guided vehicle and the robot,
A robot system in which an identification figure is arranged on one of the moving body of the machine tool or the tip of the robot, and a camera for imaging the identification figure is arranged on the other of the moving body of the machine tool or the tip of the robot. in
A method of measuring, using the machine tool, the positioning accuracy of the tip of the robot positioned by the operation of at least one of the robot and the automatic guided vehicle,
Positioning the moving body of the machine tool and the tip of the robot at a first position where the camera can capture the identification figure, capturing the identification figure with the camera, and based on the obtained image, a first step of calculating a relative positional relationship between the camera and the identification figure at the first position;
By operating at least one of the robot and the automatic guided vehicle, the tip portion of the robot is positioned in a predetermined direction at a second position moved by a predetermined target distance, and the machining is performed. a second step of moving the moving body of the machine by the same target distance in the moving direction of the tip of the robot;
Thereafter, a third step of capturing an image of the identification figure with the camera and calculating a relative positional relationship between the camera and the identification figure at a second position based on the obtained image;
and a fourth step of calculating the positioning accuracy of the distal end portion of the robot in the moving direction based on the relative positional relationship between the camera and the identification graphic at the first position and the second position. The present invention relates to a positioning accuracy measuring method for a robot system.

According to the measuring method of this aspect (first aspect), first, the robot system has an identification figure disposed on one of the moving body of the machine tool or the tip of the robot, and a camera that captures the identification figure. is disposed on the other of the moving body of the machine tool and the tip of the robot.

Next, the movable body of the machine tool and the tip of the robot are positioned at a first position where the identification figure can be imaged by the camera, and the identification figure is imaged by the camera. Based on this, the relative positional relationship between the camera and the identification figure at the first position is calculated (first step). For example, the relative positional relationship between the camera and the identification figure is calculated (recognized) by calculating the center position of the identification figure on the image based on the image including the identification figure captured by the camera.

Next, by operating at least one of the robot and the automatic guided vehicle, the distal end of the robot is moved in a predetermined direction by a predetermined target distance and positioned at a second position. , after moving the moving body of the machine tool by the same target distance in the movement direction of the tip of the robot (second step), the identification figure is imaged by the camera, and based on the obtained image, , the relative positional relationship between the camera and the identification figure at the second position is calculated (third step).

The relative positional relationship between the camera and the identification figure at the second position can be obtained by calculating the center position of the identification figure on the image based on the image containing the identification figure captured by the camera, as described above. can be obtained by The moving distance of the moving body can be directly measured using a general-purpose measuring device called a linear scale, for example, and by moving the moving body using such a measuring device, the A moving object can be moved by a target distance with high accuracy. Alternatively, when the machine tool is provided with a numerical controller and the operation of the moving body is controlled by this numerical controller, the moving body is moved under the control of this numerical controller to achieve the target It can be moved by distance with high accuracy.

Then, from the relative positional relationship between the camera and the identification figure at the first position and the second position, the positioning accuracy of the tip of the robot in the movement direction is calculated (fourth step). That is, if the moving distance of the tip of the robot to the second position and the moving distance of the moving object match with high accuracy, the (center) position of the identification figure on the image captured at the first position, The position is the same as the (center) position of the identification figure on the image captured at the second position. Therefore, by calculating the difference between the (center) position of the identification figure on the image captured at the first position and the (center) position of the identification figure on the image captured at the second position, the tip of the robot can be calculated.

As described above, according to the measuring method according to the first aspect of the present invention, by using a machine tool to which a robot system is applied without using an expensive measuring device as in the conventional art, the tip of the robot can be measured. In addition, even if it is necessary to measure the moving distance of a moving object, it is possible to measure the positioning accuracy of the tip of the robot by using a general-purpose inexpensive measuring instrument. can. Thus, according to this measuring method, the positioning accuracy of the tip of the robot can be measured inexpensively and easily.

Further, the present invention provides a robot having an end effector at its distal end and using the end effector to perform work on a machine tool;
an automatic guided vehicle equipped with the robot and passing through a work position set for the machine tool;
A control device that controls the automatic guided vehicle and the robot,
A robot system in which an identification figure is arranged on one of the moving body of the machine tool or the tip of the robot, and a camera for imaging the identification figure is arranged on the other of the moving body of the machine tool or the tip of the robot. in
A method of measuring, using the machine tool, the positioning accuracy of the tip of the robot positioned by the operation of at least one of the robot and the automatic guided vehicle,
a first step of positioning the moving body of the machine tool and the distal end portion of the robot at a first position where the identification figure can be imaged by the camera, and imaging the identification figure by the camera;
a second step of moving at least one of the robot and the automatic guided vehicle to move the distal end portion of the robot in a predetermined direction by a predetermined target distance and positioning it at a second position; ,
The moving body of the machine tool is moved in the moving direction of the tip of the robot, and the position of the identification figure captured by the camera on the camera frame is changed to the position on the camera frame of the identification figure imaged at the first position. A third step of positioning at a position coinciding with the position of and detecting the moving distance of the moving body;
a fourth step of calculating a difference value between the moving distance of the robot tip and the detected moving distance of the moving body, and determining the positioning accuracy of the robot tip in the moving direction; It relates to a positioning accuracy measuring method for a robot system.

According to the measuring method of this aspect (second aspect), first, the robot system has an identification figure provided on one of the moving body of the machine tool or the tip of the robot, and a camera for imaging the identification figure. is disposed on the other of the moving body of the machine tool and the tip of the robot.

Next, the moving body of the machine tool and the tip of the robot are positioned at a first position where the identification figure can be imaged by the camera, and the identification figure is imaged by the camera (first step). Then, for example, the position of the identification figure on the captured image is recognized by calculating the center position of the identification figure on the captured image based on the image containing the identification figure captured by the camera.

Next, by operating at least one of the robot and the automatic guided vehicle, the tip of the robot is moved in a predetermined direction by a predetermined target distance and positioned at a second position ( second step).

After that, the moving body of the machine tool is moved in the movement direction of the tip of the robot, and the position of the identification figure captured by the camera on the camera frame (captured image) is imaged at the first position. Positioning is performed so as to match the position of the identified figure on the picked-up image, and the movement distance of the moving body is detected (third step). The moving distance of the moving object can be directly measured by using a general-purpose measuring device called a linear scale, or the machine tool can be equipped with a numerical control device, as described above. When the motion of the moving body is controlled by a numerical control device, the moving distance of the moving body can be calculated based on the positional information of the moving body obtained from the numerical control device. Thus, by doing so, it is possible to recognize the movement distance of the moving object with high accuracy.

Next, a difference value between the moving distance of the robot tip and the detected moving distance of the moving body is calculated, and the positioning accuracy of the robot tip in the moving direction is calculated (fourth step).

As described above, according to the measuring method according to the second aspect of the present invention, similarly to the measuring method according to the first aspect described above, the robot system can be can be used to measure the positioning accuracy of the robot tip by using a machine tool to which the be able to. Therefore, according to this measuring method, the positioning accuracy of the tip of the robot can be measured inexpensively and easily.

Further, the present invention provides a robot having an end effector at its distal end and using the end effector to perform work on a machine tool;
an automatic guided vehicle equipped with the robot and passing through a work position set for the machine tool;
A control device that controls the automatic guided vehicle and the robot,
A detection unit is disposed on either the moving body of the machine tool or the tip of the robot, and the detected portion detected by the detection unit is set to the other of the moving body of the machine tool or the tip of the robot. In a robot system with
A method of measuring, using the machine tool, the positioning accuracy of the tip of the robot positioned by the operation of at least one of the robot and the automatic guided vehicle,
a first step of positioning the moving body of the machine tool and the distal end portion of the robot at a first position where the detected portion can be detected by the detection portion, and detecting the detected portion by the detection portion;
a second step of moving at least one of the robot and the automatic guided vehicle to move the distal end portion of the robot in a predetermined direction by a predetermined target distance and positioning it at a second position; ,
a third step of moving the moving body of the machine tool in the movement direction of the tip portion of the robot to position the detection section at a position where the detected portion is detected, and detecting the moving distance of the moving body; ,
a fourth step of calculating a difference value between the movement distance of the robot tip and the detected movement distance of the moving body, and determining the positioning accuracy of the tip of the robot in the movement direction; The present invention relates to a positioning accuracy measuring method for a robot system configured as such.

According to the measuring method of this aspect (third aspect), first, in the robot system, a detection unit is disposed on either the moving body of the machine tool or the tip of the robot, and the detection unit detects A state is set in which the detected portion is disposed on the other of the moving body of the machine tool and the tip portion of the robot.

Next, the moving body of the machine tool and the distal end portion of the robot are positioned at a first position where the detected portion can be detected by the detection portion, and the detected portion is detected by the detection portion (first position). 1 step).

After that, the moving body of the machine tool is moved in the moving direction of the tip of the robot, and the detection unit positions the detected part at a position, and detects the moving distance of the moving body ( 3rd step). The moving distance of the moving body can be directly measured by using a general-purpose measuring device called a linear scale, for example, in the same manner as described above, or alternatively, if the machine tool is equipped with a numerical controller and this numerical control is When the motion of the mobile body is controlled by the device, the moving distance of the mobile body can be calculated based on the position information of the mobile body obtained from the numerical control device. Thus, by doing so, it is possible to recognize the movement distance of the moving object with high accuracy.

As described above, according to the measuring method according to the third aspect of the present invention, similarly to the measuring methods according to the first aspect and the second aspect, the conventional expensive measuring device is not used. However, by using a machine tool to which the robot system is applied, the positioning accuracy of the robot tip can be measured. Any measuring instrument can be used. Therefore, according to this measuring method, the positioning accuracy of the tip of the robot can be measured inexpensively and easily.

As described above, according to the measuring method according to the present invention, the positioning accuracy of the tip of the robot can be measured by using a machine tool to which the robot system is applied without using an expensive measuring device as in the conventional art. can do. Moreover, even if the movement distance of the moving body is to be directly measured, a general-purpose inexpensive measuring device can be used. Therefore, according to this measuring method, the positioning accuracy of the tip of the robot can be measured inexpensively and easily.

BRIEF DESCRIPTION OF THE DRAWINGS It is the top view which showed schematic structure of the production system which concerns on the 1st Embodiment of this invention. 1 is a block diagram showing the configuration of a robot system according to a first embodiment; FIG. It is a perspective view showing the main composition of the machine tool concerning a 1st embodiment. 1 is a perspective view showing an automatic guided vehicle and a robot according to a first embodiment; FIG. FIG. 4 is an explanatory diagram showing identification figures according to the first embodiment; FIG. 4 is an explanatory diagram for explaining a positioning accuracy measuring method according to the first embodiment; FIG. 4 is an explanatory diagram for explaining a positioning accuracy measuring method according to the first embodiment; It is a perspective view showing the main composition of the machine tool concerning the modification of a 1st embodiment and a 2nd embodiment. FIG. 11 is a perspective view showing an automatic guided vehicle and a robot according to modifications of the first embodiment and the second embodiment; FIG. 11 is a perspective view showing the main configuration of a machine tool according to a third embodiment of the invention; FIG. 11 is an explanatory diagram for explaining a positioning accuracy measuring method according to the third embodiment; FIG. 11 is a perspective view showing an automatic guided vehicle and a robot according to a modified example of the third embodiment; FIG. 11 is a perspective view showing the main configuration of a machine tool according to a modified example of the third embodiment;

Specific embodiments of the present invention will be described below with reference to the drawings.

1. First Embodiment [System Configuration]
First, the system configuration according to the first embodiment of the present invention will be explained. As shown in FIGS. 1 and 2, a production system 1 of this example is composed of a robot system 20, a machine tool 100, a material stocker 120 and a product stocker 121 as peripheral devices, and the like. , an automatic guided vehicle 35, a robot 25 mounted on the automatic guided vehicle 35, a control device 40 for controlling the robot 25 and the automatic guided vehicle 35, and the like.

The machine tool 100 is a compound machining type NC machine tool controlled by a numerical controller (not shown). As shown in FIG. A first main shaft 101 and a second main shaft 103 having coaxial shafts and facing each other, a turret 108 capable of mounting a plurality of tools, and a tool rest rotatably holding the turret 108. 107 and the like.

The tool spindle 105 is driven by a first X _m -axis feed mechanism, a first Y _m -axis feed mechanism, and a first Z _m -axis feed mechanism (not shown) under the control of a numerical controller (not shown ₎ . It moves in the _m -axis and _Zm -axis directions, and similarly, the tool rest 107 moves in the _Xm -axis and _Zm -axis directions by a second Xm-axis feed mechanism and a second Zm-axis feed mechanism ₍ not shown ₎ . The Zm axis is a feed axis parallel to the axes of the first spindle 101 and the second spindle 103, the _Xm axis is a feed axis perpendicular to the Z axis in the horizontal plane, and the _Ym _axis is a feed axis in the vertical direction. It is the feed axis.

A first chuck 102 is attached to the first spindle 101 and a second chuck 104 is attached to the second spindle 103. By these first and

second chucks

102 and 104, the workpiece W to be machined is and both ends of the machined work W' are gripped. In this state, under the control of the numerical controller (not shown), the first main spindle 101 and the second main spindle 103 are rotated about their axes, and the tool main spindle 105 and the tool post 107 are moved along the X _m axis. , _Ym -axis and _Zm -axis directions, the workpiece W to be machined is machined by the tool mounted on the tool spindle 105 and the tool mounted on the turret 108 .

Incidentally, in this example, as shown in FIG. A machined work W′ is temporarily placed on this support 109 when it is removed. FIG. 3 shows a state in which the holder 110 to which the identification figure 111 is adhered is attached to the tool spindle 105. When machining is performed by the machine tool 100, the holder 110 is in the tool storage section. It is stored in a certain tool magazine (not shown), and is taken out from the tool magazine (not shown) and mounted on the tool spindle 105 when measuring the positioning accuracy of the robot system 20 .

The material stocker 120 is arranged on the left side of the machine tool 100 in FIG. The product stocker 121 is arranged on the right side of the machine tool 100 in FIG.

As shown in FIGS. 1 and 4, the automatic guided vehicle 35 has the robot 25 mounted on a mounting surface 36, which is the upper surface thereof, and is provided with an operation panel 37 that can be carried by an operator. The operation panel 37 includes an input/output unit for inputting/outputting data, an operation unit for manually operating the automatic guided vehicle 35 and the robot 25, and a display capable of displaying a screen.

Further, the automatic guided vehicle 35 is equipped with a sensor capable of recognizing its own position in the factory (for example, a distance measurement sensor using laser light), and under the control of the control device 40, the machine tool 100 , the machine tool 100, the material stocker 120 and the product stocker 121. through each working position. Incidentally, in this example, the control device 40 is arranged inside the automatic guided vehicle 35 .

The robot 25 is an articulated robot having three arms, a first arm 26, a second arm 27 and a third arm 28, which are manipulator units. is attached, and a hand 30 as an end effector is attached to the support shaft 29 . Further, a support bar 31 is attached to the support shaft 29, and a camera 32 is attached to the support bar 31 as an end effector. Under the control of the controller 40, the robot 25 moves the hand 30 and the camera 32 within a three-dimensional space defined by three orthogonal axes _xr , _yr and _zr . In this example, the _xr axis is set substantially parallel to the front surface of the automatic guided vehicle 35 .

As shown in FIG. 2, the control device 40 includes 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 manual operation control unit 45, an automatic operation control unit 46, a map It is composed of an information generation unit 47, a position recognition unit 48, an input/output interface 49, and the like. The control device 40 is connected to the machine tool 100 , the material stocker 120 , the product stocker 121 , the robot 25 , the automatic guided vehicle 35 and the operation panel 37 via the input/output interface 49 .

The control device 40 is composed of a computer including a CPU, RAM, ROM, etc. The manual operation control unit 45, the automatic operation control unit 46, the map information generation unit 47, the position recognition unit 48, and the input/output interface 49 are The function is realized by a computer program, and the processing described later is executed. The motion program storage unit 41, the movement position storage unit 42, the motion posture storage unit 43, and the map information storage unit 44 are composed of appropriate storage media such as RAM.

The manual operation control unit 45 is a functional unit that operates the unmanned guided vehicle 35 and the robot 25 according to operation signals input from the operation panel 37 by the operator. That is, the operator can manually operate the automatic guided vehicle 35 and the robot 25 using the operation panel 37 under the control of the manual operation control unit 45 .

Specifically, the manual operation control unit 45 controls, for example, the automatic guided vehicle 35 from the operation panel 37 in two orthogonal axes (x, _r , y _r axis) is input, the automatic guided vehicle 35 is moved in the direction corresponding to the input signal by the corresponding distance, and is orthogonal to the _xr axis and the _yr axis. When a signal for turning around the _zr axis (vertical axis) is input, the automatic guided vehicle 35 is turned according to the input signal.

Further, when a signal for moving the tip of the robot 25 in each of the _xr -axis, _yr -axis, and _zr -axis directions is input from the operation panel 37, the manual operation control unit 45 receives the input The tip of the robot 25 is moved by the corresponding distance in the direction corresponding to the signal. Further, when a signal for opening and closing the hand 30 is input from the operation panel 37, the manual operation control unit 45 opens and closes the hand 30 in response to the input, and receives a signal for operating the camera 32 from the operation panel 37. Then, the camera 32 is operated accordingly.

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

The automatic operation program includes command codes relating to the movement position as a target position to which the automatic guided vehicle 35 moves, the movement speed, and the orientation of the automatic guided vehicle 35. and a command code for operating the camera 32 are included. The map generation program includes command codes for causing the automatic guided vehicle 35 to travel all over the factory without a track so that the map information generation unit 47 can generate map information.

The map information storage unit 44 is a functional unit that stores map information including arrangement information of machines, devices, equipment, etc. (devices, etc.) arranged in the factory where the automatic guided vehicle 35 travels. It is generated by the map information generator 47 .

When the map information generation unit 47 causes the automatic guided vehicle 35 to travel according to the map generation program stored in the operation program storage unit 41 under the control of the automatic operation control unit 46 of the control device 40, Acquiring spatial information in the factory from the distance data detected by the sensor, and recognizing the planar shape of the equipment etc. installed in the factory, for example, based on the planar shape of the pre-registered equipment etc. The machine tool 100, the material stocker 120, and the product stocker 121 in this example, which are arranged in the factory, are recognized in terms of position, planar shape, etc. (layout information). Then, the map information generating unit 47 stores the obtained spatial information and the arrangement information of the devices, etc. in the map information storage unit 44 as map information of the factory.

The position recognition unit 48 recognizes the position and posture of the automatic guided vehicle 35 in the factory based on the distance data detected by the sensor and the map information in the factory stored in the map information storage unit 44. Based on the position and orientation of the automatic guided vehicle 35 recognized by the position recognition section 48 , the operation of the automatic guided vehicle 35 is controlled by the automatic operation control section 46 .

The movement position storage unit 42 is a movement position as a specific target position to which the automatic guided vehicle 35 moves, and is a functional unit that stores a specific movement position corresponding to the command code in the operation program. These movement positions include the work positions set for the machine tool 100, the material stocker 120, and the product stocker 121 described above. This movement position is determined, for example, by manually operating the automatic guided vehicle 35 using the operation panel 37 under the control of the manual operation control unit 45 to move it to each target position, and then performing the position recognition. It is set by the operation of storing the position data recognized by the unit 48 in the movement position storage unit 42 . This operation is called a so-called teaching operation.

The motion posture storage unit 43 stores data relating to motion postures (motion postures) of the robot 25 that sequentially change as the robot 25 moves in a predetermined order, corresponding to command codes in the motion program. is a functional unit that stores the The data relating to the motion posture is obtained when the robot 25 is manually operated by teaching operation using the operation panel 37 under the control of the manual operation control unit 45 to take each target posture. , the rotation angle data of each joint (motor) of the robot 25 in each posture, and this rotation angle data is stored in the motion posture storage unit 43 as data relating to the motion posture.

The specific motion posture of the robot 25 is set in each of the material stocker 120, the machine tool 100 and the product stocker 121. For example, in the material stocker 120, the work start posture (takeout start posture) when work is started in the material stocker 120, the unprocessed work W stored in the material stocker 120 is gripped by the hand 30, and the material stocker 120 is Each work posture (each take-out posture) for taking out from 120 and the posture when taking out is completed (take-out completion posture, which is the same posture as the take-out start posture in this example) are set as take-out motion postures. In addition, in the machine tool 100, a work take-out motion attitude for taking out the machined work W' from the machine tool 100 and a work mounting motion attitude for attaching the unmachined work W to the machine tool 100 are set.

The automatic operation control unit 46 is a functional unit that uses either the automatic operation program or the map generation program stored in the operation program storage unit 41 and operates the automatic guided vehicle 35 and the robot 25 according to the program. . At that time, the data stored in the movement position storage section 42 and the motion posture storage section 43 are used as necessary.

Thus, according to the production system 1 of the present embodiment having the above configuration, the automatic operation program stored in the operation program storage unit 41 under the control of the automatic operation control unit 46 of the control device 40 is executed, the automatic guided vehicle 35 and the robot 25 are operated according to this automatic operation program, and unmanned automatic production is executed.

[Positioning accuracy measurement method]
Next, a measuring method for measuring the positioning accuracy of the robot system 20 in the production system 1 described above will be described. In this measurement method, the machine tool 100 and the robot system 20 are manually operated under the control of a numerical control device (not shown) and the control device 40, respectively. The positioning accuracy of the tip in the _xr -axis direction shall be measured.

First, the holder 110 to which the identification figure 111 is attached is taken out from a tool magazine (not shown) and mounted on the tool spindle 105, which is the moving body of the machine tool 100, and the automatic guided vehicle 35 and the robot 25 are operated. Then, the tool spindle 105, the automatic guided vehicle 35, and the robot 25 are positioned at a position where the identification graphic 111 can be imaged by the camera 32 attached to the robot 25 (this position is referred to as a "first position"). do. At this time, the automatic guided vehicle 35 is positioned at the first position such that the _xr -axis set for itself is parallel to the _Zm -axis of the machine tool 100 . The positional relationship between the holder 110 positioned in this way and the tip of the robot 25 is indicated by a solid line in FIG. 6(a).

The positioning of the automatic guided vehicle 35 is performed based on information relating to the position and orientation of the automatic guided vehicle 35 recognized by the position recognition section 48, as described above. As shown in FIGS. 3 and 5, the identification figure 111 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 FIGS. 3 and 5, black pixels are shaded.

Next, the identification graphic 111 is imaged by the camera 32 at the first position, and the relative positional relationship between the camera 32 and the identification graphic 111 at the first position is calculated based on the obtained image. FIG. 7(a) shows an image of the identification _figure ₁₁₁ captured by the camera 32 at the first position. By calculating the center position (x _r1 , z _r1 ) of , the relative positional relationship between the camera 32 and the identification graphic 111 at the first position is obtained.

Next, the robot 25 is driven to position its tip in the _xr -axis plus direction at a position (this position is referred to as a "second position") moved by a predetermined target distance. At the same time, the tool spindle 105 is moved by the same target distance in the _Zm -axis positive direction, which is the same direction as the moving direction of the tip of the robot 25 . This state is indicated by a dashed line in FIG. 6(b). The movement distance of the tip of the robot 25 is recognized based on control position information in the manual operation control unit 45. Similarly, the movement distance of the tool spindle 105 is controlled by the numerical controller (not shown). is recognized based on the location information of

After that, the identification graphic 111 is imaged by the camera 32, and the relative positional relationship between the camera 32 and the identification graphic 111 at the second position is calculated based on the obtained image. FIG. 7(b) shows an image of the identification figure ₁₁₁ _captured by the camera 32 at the second position. By calculating the center position (x _r2 , z _r2 ) of the identification graphic 111 at , the relative positional relationship between the camera 32 and the identification graphic 111 at the second position is obtained.

Then, the relative positional relationship (x _r1 , z _r1 ) between the camera 32 and the identification figure 111 at the first position, and the relative positional relationship (x _r2 , z _r2 ), the positioning accuracy of the tip of the robot 25 in the x _r -axis direction is calculated. Specifically, the position error _Δxr corresponding to the positioning accuracy in the _xr -axis direction is calculated by the following equation.
Δx _r =x _r2 −x _r1

As described above, according to the measuring method according to the first embodiment, the robot 25 can be measured by using the machine tool 100 to which the robot system 20 is applied without using an expensive measuring device as in the conventional art. It is possible to measure the positioning accuracy of the tip portion of the tip easily and inexpensively. The positioning accuracy depends on the resolution of the camera 32. By using a high-resolution camera 32, the positioning accuracy can be measured with high accuracy.

By the way, in the measuring method according to the first embodiment, the camera 32 is arranged on the robot 25 and the identification figure 111 is arranged on the tool spindle 105 of the machine tool 100. However, the arrangement of the camera 32 and the identification figure 111 is It is relative, and as shown in FIG. 8, a camera 112 may be arranged on the tool spindle 105, and an identification figure may be arranged on the robot 25, as shown in FIG. By performing the same operation as above in this state, the positioning accuracy of the tip of the robot 25 can be measured. Incidentally, in the example shown in FIG. 8, a holder 110 holding a camera 112 is attached to the tool spindle 105 . Also, in the example shown in FIG. 9, an identification figure 111 is attached to the front surface of the support bar 31 of the robot 25 .

2. Second Embodiment Next, a measuring method according to a second embodiment of the present invention using the production system 1 described above will be described. This measurement method is also performed by manually operating the machine tool 100 and the robot system 20 under the control of a numerical control device (not shown) and the control device 40, respectively. The positioning accuracy in the _xr -axis direction of the part shall be measured.

First, in the same way as in the first embodiment, the holder 110 to which the identification figure 111 is attached is taken out from a tool magazine (not shown) and attached to the tool spindle 105, which is a moving body of the machine tool 100 ( 3), the automatic guided vehicle 35 and the robot 25 are operated, and the tool spindle 105 and the automatic guided vehicle are moved to a position (first position) where the identification graphic 111 can be imaged by the camera 32 attached to the robot 25. Position the car 35 and the robot 25 . At this time, the automatic guided vehicle 35 is positioned at the first position such that the _xr -axis set for itself is parallel to the _Zm -axis of the machine tool 100 (see FIG. 6). Then, at this first position, the identification graphic 111 is imaged by the camera 32 .

Next, the robot 25 is driven to position its tip in the _xr -axis plus direction by a predetermined target distance (second position). The robot 25 is moved in the positive direction of the _Zm axis, which is the same direction as the moving direction of the tip of the robot 25, and the position of the identification figure 111 captured by the camera 32 on the camera frame is the identification figure 111 imaged at the first position. , and the movement distance of the tool spindle 105 is detected.

The position of the identification graphic 111 on the camera frame is, for example, as shown in FIG. 7, the _{central position ((x r1} _, _{z r1} ₎ , (x _r2 , z _r2 )). Therefore, for example, based on the image captured at the first position, the center position (x _r1 , z _r1 ) of the identification graphic 111 on the captured image is calculated, and the camera 32 positioned at the second position is calculated. The tool spindle 105 is positioned such that the center position (x _r2 , z _r2 ) of the identification figure 111 imaged by , coincides with the center position (x _r1 , z _r1 ) at the first position.

After detecting the movement distance of the tool spindle 105 based on the control position information in the numerical controller (not shown), the detected movement distance of the tool spindle 105 and the movement distance of the tip of the robot 25 are calculated. The positioning accuracy of the tip of the robot 25 in the _xr -axis direction is calculated by calculating the difference value between .

As described above, according to the measurement method according to the second embodiment, similarly to the measurement method according to the first embodiment, the robot system can be By using the machine tool 100 to which 20 is applied, the positioning accuracy of the tip of the robot 25 can be measured easily and inexpensively. Also in this aspect, by using a high-resolution camera 32, the positioning accuracy can be measured with high accuracy.

Also in this embodiment, the camera 32 is arranged on the robot 25 and the identification figure 111 is arranged on the tool spindle 105 of the machine tool 100, but the arrangement of the camera 32 and the identification figure 111 is relative. A camera 112 may be arranged on the tool spindle 105 as shown in FIG. 8, and an identification figure may be arranged on the robot 25 as shown in FIG. Even in this manner, the positioning accuracy of the tip of the robot 25 can be measured by performing the same operation as described above.

3. Third Embodiment Next, a measurement method according to a third embodiment of the present invention using the production system 1 described above will be described. This measurement method is also performed by manually operating the machine tool 100 and the robot system 20 under the control of a numerical control device (not shown) and the control device 40, respectively. The positioning accuracy in the _xr -axis direction of the part shall be measured.

First, as shown in FIG. 10 , the holder 110 holding the touch probe 114 as the detection unit is taken out from a tool magazine (not shown) and mounted on the tool spindle 105 which is the moving body of the machine tool 100 . Next, the automatic guided vehicle 35 and the robot 25 are operated so that the right end face of the end face of the support bar 31 of the robot 25 moves to a position near the plus side of the touch probe 114 in the _Zm -axis direction. (first position). At this time, the automatic guided vehicle 35 is positioned at the first position such that the _xr -axis set for itself is parallel to the _Zm -axis of the machine tool 100 (see FIG. 11).

Next, the tool spindle 105 is moved in the Z _m -axis plus direction until the touch probe 114 touches the end surface of the support bar 31 and detects the support bar 31 (see FIG. 11(a)). Incidentally, the support bar 31 functions as a part to be detected for the touch probe 114 .

Next, the robot 25 is driven to move the tip end portion of the robot 25 in the positive direction of the _{xr axis by a predetermined target distance xra} _as shown in FIG. The tool spindle 105 is moved in the _Zm -axis plus direction, which is the same direction as the moving direction of the tip of the robot 25, until the touch probe 114 touches the end surface of the support bar 31 and detects the support bar 31 ( See FIG. 11(b)). Then, after the movement distance _Zma of the tool spindle 105 is detected based on the control position information in the numerical controller (not shown), the detected movement distance _Zma of the tool spindle 105 and the robot 25 The positioning accuracy of the tip of the robot 25 in the _xr -axis direction is calculated by calculating the difference from the moving distance _xra of the tip.

As described above, according to the measurement method according to the third embodiment, similarly to the measurement methods according to the first and second embodiments, a conventional expensive measurement device is used. By using the machine tool 100 to which the robot system 20 is applied, the positioning accuracy of the tip portion of the robot 25 can be measured easily and inexpensively.

Also in this embodiment, the part to be detected is set (that is, arranged) in the robot 25, and the touch probe 114 as the detection part is arranged in the tool spindle 105 of the machine tool 100. 12, the hand 30 of the robot 25 grips the touch probe 114, and as shown in FIG. 13, a block-shaped detected portion 116 is formed. Alternatively, the holder 115 may be attached to the tool spindle 105 . Also in this mode, the positioning accuracy of the tip of the robot 25 can be measured by performing the same operation as described above.

Although the specific embodiments of the present invention have been described above, the aspects that the present invention can take are not limited to these.

For example, in the first, second and third embodiments described above, the positioning accuracy of the tip of the robot 25 in the _xr -axis direction is measured. By the operation, the positioning accuracy of the tip of the robot 25 in the _zr -axis direction can be measured. Further, the positioning accuracy of the automatic guided vehicle 35 in the _xr -axis direction can be measured by a similar operation, not limited to the robot 25 . Furthermore, the positioning accuracy of the tip of the robot 25 in the _xr -axis direction or the _zr -axis direction in the combined operation of the automatic guided vehicle 35 and the robot 25, that is, in a mode in which both are moved, is measured by the same operation as above. can do.

Also, the moving distance of the tool spindle 105 as a moving body can be directly measured using, for example, a general-purpose inexpensive measuring instrument called a linear scale.

Also, the identification figure is not limited to the above example, and may be of any shape as long as the relative positional relationship between the camera and the identification figure can be obtained from the captured image.

Again, the above description of the embodiment is illustrative in all respects and is not restrictive. Modifications and modifications are possible for those skilled in the art. The scope of the invention is indicated by the claims rather than the above-described embodiments. Furthermore, the scope of the present invention includes modifications from the embodiments within the scope of claims and equivalents.

1 production system 20 robot system 25 robot 26 first arm 27 second arm 28 third arm 30 hand 31 support bar 32 camera 35 unmanned guided vehicle 37 operation panel 40 control device 41 operation program storage unit 42 movement position storage unit 43 operation attitude Storage unit 44 Map information storage unit 45 Manual operation control unit 46 Automatic operation control unit 47 Map information generation unit 48 Position recognition unit 49 Input/output interface 100 Machine tool 101 First spindle 103 Second spindle 105 Tool spindle 110 Holder 111 Identification figure 120 Material stocker 121 Product stocker

Claims

a robot having an end effector at its tip and using the end effector to work on a machine tool;
an automatic guided vehicle equipped with the robot and passing through a work position set for the machine tool;
A control device that controls the automatic guided vehicle and the robot,
A robot system in which an identification figure is arranged on one of the moving body of the machine tool or the tip of the robot, and a camera for imaging the identification figure is arranged on the other of the moving body of the machine tool or the tip of the robot. in
A method of measuring, using the machine tool, the positioning accuracy of the tip of the robot positioned by the operation of at least one of the robot and the automatic guided vehicle,
Positioning the moving body of the machine tool and the tip of the robot at a first position where the camera can capture the identification figure, capturing the identification figure with the camera, and based on the obtained image, a first step of calculating a relative positional relationship between the camera and the identification figure at the first position;
By operating at least one of the robot and the automatic guided vehicle, the tip portion of the robot is positioned in a predetermined direction at a second position moved by a predetermined target distance, and the machining is performed. a second step of moving the moving body of the machine by the same target distance in the moving direction of the tip of the robot;
Thereafter, a third step of capturing an image of the identification figure with the camera and calculating a relative positional relationship between the camera and the identification figure at a second position based on the obtained image;
and a fourth step of calculating the positioning accuracy of the distal end portion of the robot in the moving direction based on the relative positional relationship between the camera and the identification graphic at the first position and the second position. A positioning accuracy measuring method for a robot system, characterized by:
a robot having an end effector at its tip and using the end effector to work on a machine tool;
an automatic guided vehicle equipped with the robot and passing through a work position set for the machine tool;
A control device that controls the automatic guided vehicle and the robot,
A robot system in which an identification figure is arranged on one of the moving body of the machine tool or the tip of the robot, and a camera for imaging the identification figure is arranged on the other of the moving body of the machine tool or the tip of the robot. in
A method of measuring, using the machine tool, the positioning accuracy of the tip of the robot positioned by the operation of at least one of the robot and the automatic guided vehicle,
a first step of positioning the moving body of the machine tool and the distal end portion of the robot at a first position where the identification figure can be imaged by the camera, and imaging the identification figure by the camera;
a second step of moving at least one of the robot and the automatic guided vehicle to move the distal end portion of the robot in a predetermined direction by a predetermined target distance and positioning it at a second position; ,
The moving body of the machine tool is moved in the moving direction of the tip of the robot, and the position of the identification figure captured by the camera on the camera frame is changed to the position on the camera frame of the identification figure imaged at the first position. A third step of positioning at a position coinciding with the position of and detecting the moving distance of the moving body;
a fourth step of calculating a difference value between the moving distance of the robot tip and the detected moving distance of the moving body, and determining the positioning accuracy of the robot tip in the moving direction; A positioning accuracy measuring method for a robot system, characterized by:
a robot having an end effector at its tip and using the end effector to work on a machine tool;
an automatic guided vehicle equipped with the robot and passing through a work position set for the machine tool;
A control device that controls the automatic guided vehicle and the robot,
A detection unit is disposed on either the moving body of the machine tool or the tip of the robot, and the detected portion detected by the detection unit is set to the other of the moving body of the machine tool or the tip of the robot. In a robot system with
A method of measuring, using the machine tool, the positioning accuracy of the tip of the robot positioned by the operation of at least one of the robot and the automatic guided vehicle,
a first step of positioning the moving body of the machine tool and the distal end portion of the robot at a first position where the detected portion can be detected by the detection portion, and detecting the detected portion by the detection portion;
a second step of moving at least one of the robot and the automatic guided vehicle to move the distal end portion of the robot in a predetermined direction by a predetermined target distance and positioning it at a second position; ,
a third step of moving the moving body of the machine tool in the movement direction of the tip portion of the robot to position the detection section at a position where the detected portion is detected, and detecting the moving distance of the moving body; ,
a fourth step of calculating a difference value between the movement distance of the robot tip and the detected movement distance of the moving body, and determining the positioning accuracy of the tip of the robot in the movement direction; A positioning accuracy measuring method for a robot system, characterized by:
The machine tool is equipped with a numerical controller,
3. The positioning accuracy measuring method for a robot system according to claim 1, wherein, in said third step, the moving distance of said moving body is calculated based on the positional information of said moving body obtained from said numerical controller. .