The present invention relates to a control device, a robot, and a robot system.
From the related art, a robot system which is used in work of gripping, transporting, and assembling a target, such as an electronic component, is known. The robot system includes: a robot including a robot arm having a plurality of arms, and a hand provided at a tip end thereof; an imaging portion, such as a camera; and a control device which controls each of the robot and the imaging portion. In a robot system having such a configuration, for example, the robot performs various types of work with respect to the target with the hand based on an image of the target captured by the imaging portion.
Here, it is necessary to calibrate the imaging portion which acquires a correction parameter for converting a position and a posture on the image of the target captured by the imaging portion into a value in a robot coordinate system such that the robot accurately performs the work with respect to the target based on the image captured by the imaging portion.
For example, in JP-A-8-210816, processing of acquiring the parameter which converts a position on the image into a value in the robot coordinate system by using a robot-visual sensor system (robot system) is described. The robot-visual sensor system described in JP-A-8-210816 includes: a robot including a robot arm and a touch-up hand provided at a tip end thereof; a visual sensor (imaging portion) provided at the tip end of the robot arm; and a calibration tool provided with a plane having three standard points and four reference points.
In the processing described in JP-A-8-210816, first, by bringing the touch-up hand into contact with the three standard points, the position and the posture of the calibration tool in the robot coordinate system are specified. After this, by capturing the four reference points using the visual sensor by driving the robot arm, and by determining the position of the calibration tool in an image coordinate system of the imaging portion, the parameter which converts a position on the image into a value in the robot coordinate system is acquired.
However, in the processing described in JP-A-8-210816, as described above, by bringing the touch-up hand into contact with the three standard points, the position of the calibration tool in the robot coordinate system is specified. In the calibration of the related art, in general, since a worker confirms a contact state between the calibration tool and the touch-up hand, differences in determination of the contact state are generated according to a worker. Therefore, it is difficult to specify the position and the posture of the calibration tool with high accuracy, and when a worker desires to accurately perform determination of the contact state, there is a problem that it takes a long time to specify the position and the posture of the calibration tool. In addition, a problem that there are a lot of work that is directly performed by the worker, and it takes a longer time to specify the position and the posture of the calibration tool as the number of robots, cameras, and standard surfaces which are calibration target increases, becomes serious.
An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following configurations.
A control device according to an aspect of the invention includes: a control portion which operates a robot including a movable portion capable of being provided with an end-effector that works with respect to a target; and a receiving portion which receives an input command and outputs a signal based on the received input command to the control portion, in which the control portion is capable of allowing the robot to perform two or more works selected from first work of performing calibration between a coordinate system of a first imaging portion having an imaging function and a coordinate system of the robot, second work of performing calibration between a coordinate system of a second imaging portion having an imaging function and a coordinate system of the robot, third work of calculating a posture of a virtual standard surface that corresponds to a work surface on which the robot works, fourth work of calculating a distance between the first imaging portion and a standard point of the robot, and fifth work of calculating a distance between the end-effector and the standard point, based on one input command received by the receiving portion.
According to the control device according to the aspect of the invention, since it is possible to collectively perform the plural types of work selected from the first work to the fifth work by the control portion by one input command input to the receiving portion, it is possible to increase work efficiency. In addition, the operation by the worker is also easy.
In the control device according to the aspect of the invention, it is preferable that the first imaging portion is provided in the movable portion.
With this configuration, for example, it is possible to allow the robot to accurately perform the work with respect to the target based on the image captured by the first imaging portion.
In the control device according to the aspect of the invention, it is preferable that the second imaging portion is provided at a place other than the movable portion.
With this configuration, for example, it is possible to allow the robot to accurately perform the work with respect to the target based on the image captured by the second imaging portion. In addition, it is possible to easily grasp whether or not the target is accurately gripped or the like by the end-effector.
In the control device according to the aspect of the invention, it is preferable that the control portion is capable of allowing the robot to perform the first work, the second work, the third work, the fourth work, and the fifth work, based on the one input command received by the receiving portion.
With this configuration, since all of the first work to the fifth work can be collectively performed, it is possible to improve work efficiency of all of the first work to the fifth work.
In the control device according to the aspect of the invention, it is preferable that the receiving portion is capable of receiving that at least one of the first work, the second work, the third work, the fourth work, and the fifth work is not selectively performed.
With this configuration, it is possible to omit the performing of desirable work among the first work to the fifth work, and to efficiently perform only the work desired to be performed.
In the control device according to the aspect of the invention, it is preferable that the control portion outputs a signal that displays a setting screen for setting the work contents of each of the first work, the second work, the third work, the fourth work, and the fifth work, based on the one input command received by the receiving portion.
With this configuration, it is possible to display a setting screen (window) for setting the work contents of each work in display equipment including the screen. Therefore, the worker can simply set the work contents by operating the displayed setting screen.
In the control device according to the aspect of the invention, it is preferable that the end-effector is attached to a member included in the movable portion, the member included in the movable portion is rotatable around a rotation axis, and the standard point is positioned on the rotation axis.
With this configuration, for example, by performing the fifth work, since the distance between the end-effector and the standard point (axial coordinates O6) positioned in the member (sixth arm) included in the movable portion (robot arm) is acquired, it is possible to accurately perform the work with respect to the target by the robot.
A robot according to an aspect of the invention is controlled by the control device according to the aspect of the invention.
According to the robot according to the aspect of the invention, it is possible to accurately perform various types of work.
A robot system according to an aspect of the invention includes: the control device according to the aspect of the invention; and a robot which is controlled by the control device.
According to the robot system according to the aspect of the invention, the robot can accurately perform various types of work.
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
Hereinafter, a control device, a robot, and a robot system according to the invention will be described based on appropriate embodiments illustrated in the attached drawings.
In addition, hereinafter, for convenience of the description, an upper side in
A robot system 100 illustrated in
As illustrated in
In addition, in the embodiment, in the work region 90, a supply stand 61 (pickup place) in which the target 60 is supplied to the robot 1 by a worker, and an inspection stand 62 (inspection stage) on which the target 60 is inspected or the like, are provided. Each of the supply stand 61 and the inspection stand 62 is provided within a driving range of the robot arm 10 of the robot 1.
Hereinafter, each portion of the robot system 100 will be described in order.
Robot
The robot 1 illustrated in
The robot 1 is a 6-axis vertical articulated robot, and includes a base 101, a robot arm 10 which is connected to the base 101, and a hand 102 (tool) which is an end-effector provided at the tip end part of the robot arm 10. In addition, as illustrated in
The base 101 is a part which attaches the robot 1 to a predetermined location in the work region 90.
The robot arm 10 includes a first arm 11 (arm), a second arm 12 (arm), a third arm 13 (arm), a fourth arm 14 (arm), a fifth arm 15 (arm), and a sixth arm 16 (arm). The first arm 11 is connected to the base 101, and the first arm 11, the second arm 12, the third arm 13, the fourth arm 14, the fifth arm 15, and the sixth arm 16 are linked to each other in order from the based end side to the tip end side.
As illustrated in
The hand 102 is attached to the tip end surface of the sixth arm 16 such that the center axis of the hand 102 matches the rotation axis A6 of the sixth arm 16, on the design. Here, the center of the tip end surface of the hand 102 is referred to as a tool center point (TCP). In the embodiment, the center is referred to as the center of a region between two fingers of the hand 102.
In addition, in each of the arms 11 to 16, the plurality of driving portions 130 including a motor, such as a servo motor, and a speed reducer, are respectively provided. In other words, as illustrated in
In addition, in each driving portion 130, for example, an angle sensor (not illustrated), such as an encoder or a rotary encoder, is provided. Accordingly, it is possible to detect the rotation angle of the rotation axis of the motor or the speed reducer of each driving portion 130.
In addition, as illustrated in
The robot 1 that is an example of a robot according to the invention is controlled by the control device 5 that is an example of a control device according to the invention which will be described later. Therefore, it is possible to provide the robot 1 that performs more accurate work.
The second fixed camera 2 illustrated in
As illustrated in
The second fixed camera 2 is fixed at the predetermined location in the work region 90 to be capable of capturing an upper part in the vertical direction. In addition, in the embodiment, the second fixed camera 2 is attached such that the optical axis OA2 (the optical axis of the lens 22) is substantially parallel to the vertical direction.
In this manner, in the embodiment, the second fixed camera 2 which is a second imaging portion is provided in the work region 90 which is at a place other than the robot 1 including the robot arm 10 that is the movable portion. Accordingly, for example, it is possible to allow the robot 1 to accurately perform the work with respect to target 60 based on the image captured by the second fixed camera 2. In addition, as the second fixed camera 2 is provided at a place other than the robot arm 10, for example, it is easy to confirm whether or not the hand 102 attached to the robot arm 10 accurately grips the target 60.
In addition, in the embodiment, as an image coordinate system (coordinate system of the image output from the second fixed camera 2) of the second fixed camera 2, a two-dimensional orthogonal coordinate system which is determined by an xa axis and a ya axis that are respectively parallel to the in-plane direction of the image, is set. In addition, a translational component with respect to the xa axis is “component xa”, a translational component with respect to the ya axis is “component ya”, and a rotational component around a normal line of an xa-ya plane is “component ua”. The unit of a length (size) of the component xa and the component ya is “pixel”, and the unit of an angle (size) of the component ua is “°”.
In addition, the image coordinate system of the second fixed camera 2 is a two-dimensional orthogonal coordinate system which nonlinearly converts the three-dimensional orthogonal coordinates that are given to a camera viewing field of the second fixed camera 2 by adding optical properties (focal length, distortion, or the like) of the lens 22 and the number of pixels and the size of the imaging element 21.
The third fixed camera 9 illustrated in
As illustrated in
The third fixed camera 9 is provided on the inspection stand 62 to be capable of capturing an upper part in the vertical direction of an inspection surface 621 (work surface) which is an upper surface of the inspection stand 62. In addition, the inspection surface 621 of the inspection stand 62 can be in a state parallel to the horizontal direction, and additionally, can be in a state of being inclined with respect to the horizontal direction. In addition, in the embodiment, the third fixed camera 9 is attached such that the optical axis OA9 (optical axis of the lens 92) is substantially parallel to the vertical direction.
In addition, in the embodiment, as an image coordinate system (coordinate system of the image output from the third fixed camera 9) of the third fixed camera 9, a two-dimensional orthogonal coordinate system which is determined by an xc axis and a yc axis, is set. A translational component with respect to the xc axis is “component xc”, a translational component with respect to the yc axis is “component yc”, and a rotational component around a normal line of an xc-yc plane is “component uc”. The unit of a length (size) of the component xc and the component yc is “pixel”, and the unit of an angle (size) of the component uc is “°”.
The mobile camera 3 illustrated in
As illustrated in
The mobile camera 3 is attached to the sixth arm 16 so as to be also capable of capturing the tip end side of the robot arm 10 than the sixth arm 16. In addition, in the embodiment, on the design, the mobile camera 3 is attached to the sixth arm 16 such that the optical axis OA3 (optical axis of the lens 32) is substantially parallel to the rotation axis A6 of the sixth arm 16. In addition, since the mobile camera 3 is attached to the sixth arm 16, it is possible to change the posture thereof together with the sixth arm 16 by driving the robot arm 10.
In this manner, the mobile camera 3 which is a first imaging portion is provided in the sixth arm 16 included in the robot arm 10 which is a movable portion. Accordingly, for example, it is possible to allow the robot 1 to accurately perform the work with respect to the target 60 based on the image captured by the mobile camera 3.
In addition, in the embodiment, as the image coordinate system (coordinate system of the image output from the mobile camera 3) of the mobile camera 3, a two-dimensional orthogonal coordinate system which is determined by an xb axis and a yb axis that are respectively parallel to the in-plane direction of the image. In addition, a translational component with respect to the xb axis is “component xb”, a translational component with respect to the yb axis is “component yb”, and a rotational component around a normal line of an xb-yb plane is “component ub”. The unit of a length (size) of the component xb and the component yb is “pixel”, and the unit of an angle (size) of the component ub is “°”.
In addition, the image coordinate system of the mobile camera 3 is a two-dimensional orthogonal coordinate system which nonlinearly converts the three-dimensional orthogonal coordinate that is given to a camera viewing field of the mobile camera 3 by adding optical properties (focal length, distortion, or the like) of the lens 32 and the number of pixels and the size of the imaging element 31.
The control device 5 illustrated in
As illustrated in
The control portion 51 can control the driving of each of the driving portions 130, and can drive and stop each of the arms 11 to 16 independently. For example, in order to move the hand 102 to a target position, the control portion 51 derives a target value of the motor of each of the driving portions 130 provided in each of the arms 11 to 16. In addition, the control portion 51 feedback-controls the robot 1 based on the rotation angle (detection result) output from the angle sensor included in each of the driving portions 130. In addition, the control portion 51 controls the capturing or the like of the second fixed camera 2, the third fixed camera 9 and the mobile camera 3.
In addition, the control portion 51 has a function as a processing portion. In other words, the control portion 51 performs processing of various types of calculation or various types of determination based on the detection result obtained by the receiving portion 52. For example, the control portion 51 calculates the coordinates (components xa, ya, and ua: the position and the posture) of the imaging target in the image coordinate system of the second fixed camera 2 based on the image captured by the second fixed camera 2, calculates the coordinates (components xc, yc, and uc: the position and the posture) of the imaging target in the image coordinate system of the third fixed camera 9 based on the image captured by the third fixed camera 9, and calculates the coordinates (components xb, yb, and ub: the position and the posture) of the imaging target in the image coordinate system of the mobile camera 3 based on the image captured by the mobile camera 3. In addition, for example, the control portion 51 acquires the correction parameter for converting the coordinates of the target 60 in the image coordinate system of the second fixed camera 2 into the coordinates in the robot coordinate system, acquires the correction parameter for converting the coordinates of the target 60 in the image coordinate system of the third fixed camera 9 into the coordinates in the robot coordinate system, and acquires the correction parameter for converting the coordinates of the target 60 in the image coordinate system of the mobile camera 3 into the coordinates in the robot coordinate system.
The receiving portion 52 obtains the detection result output from each of the robot 1, the second fixed camera 2, the third fixed camera 9, and the mobile camera 3. Examples of the detection result include the rotation angle of the rotation axis of the motor or the speed reducer of each of the driving portions 130 of the robot 1, the image captured by each of the second fixed camera 2, the third fixed camera 9, and the mobile camera 3, and the coordinates (components xr, yr, zr, ur, vr, and wr: the position and the posture) of the axial coordinates O6 in the robot coordinate system.
The storage portion 54 stores a program or data for performing various types of processing by the control device 5, and the storage portion 54 stores various detection results.
In addition, as illustrated in
The display equipment 41 includes a monitor which is configured of a display panel, such as a liquid crystal display panel including a screen 410. On the screen 410, for example, various windows are displayed, such as a window WD1 which is used when allowing the robot 1 to perform the work. The worker can confirm the image or the like captured by the second fixed camera 2, the third fixed camera 9, and the mobile camera 3, via the screen 410.
The operation equipment 42 is an input device which is configured of a mouse or a keyboard, and outputs a signal which is based on an instruction of the worker to the control device 5. Therefore, the worker can instruct various types of processing or the like to the control device 5 by operating the operation equipment 42. In addition, as the operation equipment 42, a touch panel or the like may be employed.
Above, a basic configuration of the robot system 100 is briefly described.
The robot system 100 which is an example of a robot system according to the invention includes the control device 5 which is an example of a control device according to the invention, and the robot 1 which is controlled by the control device 5. Therefore, the robot 1 can accurately perform various types of work by the control of the control device 5.
In addition, in the above-described robot system 100, for example, the robot 1 can perform the following work with respect to the target 60 by the control of the control device 5 based on a program stored in advance.
First, the target 60 mounted on a supply surface 611 which is an upper surface of the supply stand 61 is gripped by the hand 102 by driving the robot arm 10. After this, in a state where the target 60 is gripped by the hand 102, the hand 102 is moved onto the second fixed camera 2 by driving the robot arm 10. Next, the target 60 is captured by the second fixed camera 2, and based on the image captured by the second fixed camera 2, the control device 5 determines whether or not the target 60 is accurately gripped by the hand 102. When accurately gripping the target 60, the hand 102 is moved onto the inspection stand 62 by driving the robot arm 10. In addition, based on the image captured by the mobile camera 3, the target 60 gripped by the hand 102 is mounted onto the inspection stand 62. In mounting the target 60, the target 60 is captured by the third fixed camera 9, and based on the image captured by the third fixed camera 9, the control device 5 determines whether or not the target 60 can be accurately mounted on the inspection stand 62.
In the work with respect to the target 60, the control device 5 controls the operation of the robot 1 based on the instruction of the worker via the window WD1 displayed on the screen 410 illustrated in
As illustrated in
The worker performs various instructions with respect to the control portion 51 via the window WD1. For example, when the worker clicks (instructs) the “Start” button by the operation equipment 42, such as a mouse, the receiving portion 52 receives an input command based on the instruction. In addition, based on the input command received by the receiving portion 52, the control portion 51 allows the robot 1 to start the work with respect to the target 60.
As described above, in the embodiment, since the window WD1 having various buttons configured of the GUI is provided, the worker can simply instruct the work with respect to the target 60 of the robot 1, with respect to the control device 5 only by a relatively simple operation which is called clicking of a desirable button.
In addition, although not illustrated, the window WD1 may be provided with, for example, a combo box that can select a work program of the robot 1. Accordingly, it is possible to select a desirable work program from the drop-down list, and to perform the selected program.
In the work with respect to the target 60 of the robot 1, it is necessary to perform processing of acquiring a correction parameter for converting the coordinates (the position and the posture in the image coordinate system) on the image of the second fixed camera 2 into the coordinates in the robot coordinate system, that is, the calibration of the second fixed camera 2, such that the robot 1 accurately performs the work with respect to the target 60 based on the image captured by the second fixed camera 2. Regarding the third fixed camera 9 and the mobile camera 3, the calibration of the third fixed camera 9 and the calibration of the mobile camera 3 are similarly necessary.
Hereinafter, a calibration method of the second fixed camera 2, a calibration method of the third fixed camera 9, and a calibration method of the mobile camera 3 (hereinafter, the methods are collectively called “calibration method of the imaging portion”) which use the robot system 100, will be described.
As illustrated in
In addition, the calibration of the imaging portion illustrated in
The window WD2 illustrated in
As illustrated in
The item 461 has an “Execute Cam #1 Calib(1)” button which is a command button used for giving the instruction (command) to the control portion 51 to independently perform the calibration (step S1) of the mobile camera 3 on the supply stand 61. This is the same regarding each of the items 462 and 466. In other words, the item 462 has an “Execute TLset” button which is a performing button, the item 463 has an “Execute Cam #2 Calib” button which is a command button, the item 464 has an “Execute Stage Calib” button which is a command button, the item 465 has an “Execute Cam #1 Calib (2)” button which is a command button, and the item 466 has an “Execute Cam #3 Calib” button which is a command button.
When the worker clicks (instructs) the command button by the operation equipment 42, such as a mouse, the receiving portion 52 receives an input command that corresponds to the instruction. In addition, the control portion 51 displays the window WD3 (setting screen) for performing various settings of the calibration that corresponds to the items 461 to 466 having the clicked command buttons (refer to
As illustrated in
Examples of the setting contents (work contents) included in the item 471 include the setting of ON/OFF of illumination included in the imaging portion and the quantity of light of the illumination. In addition, the setting contents (work contents) included in the item 471 are not limited to the illustrated contents, and are arbitrary. In addition, examples of the setting method include a method of selecting the desirable contents from the drop-down list, or a method of inputting numerical values or characters which correspond to the desirable contents into a text box. In addition, the setting contents which cannot be set are grayed out so as not to be selected, or may not be displayed.
The item 472 includes a “Jog & Teach (Robot Manager)” button B31, an “Open Vision Guide” button B32, and an “Execute Calibration” button B33. The “Jog & Teach (Robot Manager)” button B31 is used for displaying a window for operating the robot 1 in addition to the window WD3. The “Open Vision Guide” button B32 is used for displaying a window on which the setting or the like of the template for identifying an image of a predetermined marker in the imaging portion is performed, in addition to the window WD3. The “Execute Calibration” button B33 is a performing button that gives an instruction to perform the start of the calibration displayed on the window WD3 to the control portion 51. Therefore, when the worker clicks (instructs) the “Execute Calibration” button B33 by the operation equipment 42, such as a mouse, the receiving portion 52 receives the input command that corresponds to the instruction. In addition, based on the input command received by the receiving portion 52, the control portion 51 starts the processing that corresponds to the window WD3.
In addition, as illustrated in
In addition, the window WD2 has a “Continuous execution” button B21 and a “Step by step execution” button B22. The “Continuous execution” button B21 and the “Step by step execution” button B22 are respectively performing buttons which are used for giving the instruction to the control portion 51 to collectively perform the processing that corresponds to the items 461 to 466 to which checks are attached to the check boxes C461 to 466. In addition, the processing which corresponds to the items 461 to 466 to which the checks are not attached is not performed, and the processing is skipped.
More specifically, the “Continuous execution” button B21 is used for continuously performing the processing that corresponds to the items 461 to 466 to which the checks are attached. Therefore, when the worker clicks (instructs) the “Continuous execution” button B21 by the operation equipment 42, such as a mouse, the receiving portion 52 receives the input command which corresponds to the instruction. In addition, based on the input command received by the receiving portion 52, the control portion 51 performs the processing that corresponds to the items 461 to 466 to which the checks are attached following the flow illustrated in
Meanwhile, the “Step by step execution” button B22 is used for gradually performing the processing that corresponds to the items 461 to 466 to which the check is attached. Therefore, when the worker clicks (instructs) the “Step by step execution” button B22 by the operation equipment 42, such as a mouse, the receiving portion 52 receives the input command that corresponds to the instruction. In addition, based on the input command received by the receiving portion 52, the control portion 51 performs the processing that corresponds to the items 461 to 466 to which the checks are attached following the flow illustrated in
As described above, the control device 5 which is an example of a control device according to the invention includes the control portion 51 which operates the robot 1 including the robot arm 10 that is the movable portion to which the hand 102 which is an end-effector that performs the work with respect to the target 60 is attached to be attachable and detachable; and the receiving portion 52 which receives the input command based on the instruction of the worker and outputs the signal based on the received input command to the control portion 51. In addition, the control portion 51 can collectively perform two or more of the processings among the calibration of the mobile camera 3 on the supply stand 61 (step S1), the calibration of the hand 102 which is an end-effector (step S2), the calibration of the second fixed camera 2 (step S3), the specifying of the standard surface that corresponds to the inspection surface 621 of the inspection stand 62 (step S4), the calibration of the mobile camera 3 on the inspection stand 62 (step S5), and the calibration of the third fixed camera 9 (step S6), based on the signal from the receiving portion 52. In other words, the control portion 51 can display the “Continuous execution” button B21 and the “Step by step execution” button B22 which are performing buttons (GUI button) on the screen 410 included in the display equipment 41, and the window WD2 including the check boxes C461 to 466. In addition, the control portion 51 can collectively perform the plural types of processing (calibration) based on the input command that corresponds to the instruction (click) of the worker with respect to the performing buttons. In this manner, since the control device 5 can collectively perform the plural types of selected calibration (work) by one input command with respect to the receiving portion 52, the setting of the calibration is easy, it is possible to perform the calibration during a short period of time, and efficiency is excellent. In addition, the operation performed by the worker is also easy.
In addition, the calibration method will be described in detail later, but in the calibration of the mobile camera 3 on the supply stand 61 (step S1) or in the calibration of the mobile camera 3 on the inspection stand 62 (step S5), first work of performing the calibration of the coordinate system of the mobile camera 3 which is the first imaging portion having the imaging function and the coordinate system of the robot 1, is performed. In addition, in the calibration of the second fixed camera 2 (step S3), second work of performing the calibration of the coordinate system of the second fixed camera 2 which is the second imaging portion having the imaging function and the coordinate system of the robot 1, is performed. In addition, in the specifying of the standard surface that corresponds to the inspection surface 621 of the inspection stand 62 (step S4), third work of calculating the posture of a virtual standard surface that corresponds to the work surface on which the robot 1 works, is performed. In addition, in the calibration of the mobile camera 3 on the supply stand 61 (step S1) or in the calibration of the mobile camera 3 on the inspection stand 62 (step S5), fourth work of calculating the distance between mobile camera 3 which is the first imaging portion and the axial coordinates O6 which is the standard point of the robot 1, is performed. In addition, in the calibration of the hand 102 which is the end-effector (step S2), fifth work of calculating the distance between the hand 102 which is the end-effector and the axial coordinates O6 which is the standard point, is performed.
In addition, the control portion 51 can collectively perform all of the processing of each of the steps S1 to S6 based on the signal from the receiving portion 52. In other words, the control portion 51 can collectively perform the above-described first work, the second work, the third work, the fourth work, and the fifth work. Accordingly, it is possible to improve the work efficiency of all of the first work to fifth work.
In addition, as described above, the control portion 51 can display the window WD2 having the check boxes C461 to 466 on the screen 410 included in the display equipment 41. In addition, the receiving portion 52 is configured to be capable of receiving an instruction that at least one of the processing steps S1 to S6 is not selectively performed. In other words, the receiving portion 52 is configured to be capable of receiving that at least one of the first work, the second work, the third work, the fourth work, and the fifth work is not selectively performed. Accordingly, it is possible to omit the performing of the desirable work among the first work to the fifth work, and to efficiently perform only the work desired to be performed.
In addition, the control portion 51 outputs a signal to display the setting screen for setting each of the setting contents (work contents) in each processing of the steps S1 to S6, based on the signal from the receiving portion 52. Accordingly, it is possible to display the window WD3 (setting screen) on the screen 410 of the display equipment 41. In other words, the control portion 51 can output the signal to display the window WD3 which is the setting screen for setting the work contents of each of the first work, the second work, the third work, the fourth work, and the fifth work. Therefore, the worker can simply set the work contents by operating the displayed window WD3.
As described above, in the embodiment, the calibration of the imaging portion is performed by using the calibration member 70 (calibration board) illustrated in
The calibration member 70 is a member having a shape of a quadrangle flat plate, and a plurality of markers 75 are attached to a front surface 701 of the calibration member 70. The plurality of markers 75 have the same circular shape and have substantially the same size. In addition, the plurality of markers 75 are disposed such that all of the pitches (intervals) between the adjacent markers 75 are substantially constant. In addition, the pitches between the markers 75 are measured in advance and is known.
Circles which surround the markers 75 are further respectively attached to the marker 75 which is positioned on an upper side in
In addition, the shapes of the plurality of markers 75, the first marker 71, the second marker 72, and the third marker 73 may respectively be any shape not being limited to the shape illustrated in the drawing. In addition, the marker 75, the first marker 71, the second marker 72, and the third marker 73 may be an aspect which can be visually recognized, may be in any color, and may be an aspect having unevenness, respectively. In addition, the aspects of the plurality of markers 75, the first marker 71, the second marker 72 and the third marker 73 may be different from each other. For example, the plurality of markers 75, the first marker 71, the second marker 72, and the third marker 73 may respectively be in any color or shape. However, since the first marker 71, the second marker 72, and the third marker 73 are used as the standard markers, it is preferable that the first marker 71, the second marker 72, and the third marker 73 are discerned from other markers 75.
As described above, in the calibration of the imaging portion of the embodiment, the calibration of the mobile camera 3 on the supply stand 61 (step S1), the calibration of the hand 102 which is the end-effector (step S2), the calibration of the second fixed camera 2 (step S3), the specifying of the standard surface that corresponds to the inspection surface 621 of the inspection stand 62 (step S4), the calibration of the mobile camera 3 on the inspection stand 62 (step S5), and the calibration of the third fixed camera (step S6), are performed in order (refer to
In addition, in the embodiment, when performing the calibration of the imaging portion, robot calibration, that is, processing of acquiring the correspondence of the coordinate system of the hand 102 with respect to the coordinate system (base coordinate system) of the robot 1 may be performed in advance.
First, the control device 5 starts the calibration (step S1) of the mobile camera 3 on the supply stand 61. In addition, before starting the calibration (step S1), as illustrated in
The calibration (step S1) is substantially similar to the calibration (step S5) of the mobile camera 3 on the inspection stand 62 which will be described later, except for that the calibration of the mobile camera 3 is performed on the supply stand 61 instead of the inspection stand 62. Therefore, specific description (processing contents and effects) thereof will be omitted, but in the calibration (step S1), the processing of acquiring the offset components which will be described later, the processing of specifying the inspection surface, the processing of instructing the position and the posture of the marker to the robot 1, and the processing of acquiring the relationship between the image coordinate system of the mobile camera 3 and the robot coordinate system, are performed (refer to
Calibration of Hand 102 which is End-Effector (Step S2)
Next, as illustrated in
Here, as described above, the hand 102 is attached to the sixth arm 16 such that the TCP is positioned on the rotation axis A6 of the sixth arm 16, on the design. However, practically, there is a case where the TCP is positioned being slightly shifted from the rotation axis A6 of the sixth arm 16 by an assembly error or the like of the hand 102 to the sixth arm 16. Here, toolset processing for deriving and setting the offset components (the position and the posture of the hand 102 with respect to the sixth arm 16) which are a shift of the rotation axis A6 of the TCP, is performed.
First, the control portion 51 moves the robot arm 10 such that the second marker 72 is positioned at a center O20 (centroid) of an image 20 of the second fixed camera 2, and moves the axial coordinates O6 of the sixth arm 16 such that the second marker 72 is positioned at the center O20 of the image 20 (refer to
Next, the control portion 51 outputs the derived target value and moves the robot arm 10. As a result, the axial coordinates O6 translationally moves in each of the xr-axis direction and the yr-axis direction, a positional relationship of the second fixed camera 2, the axial coordinates O6, and the second marker 72 becomes a state A, and the second marker 72 is positioned at the center O20 of the image 20 captured by the second fixed camera 2 as illustrated in
Next, the control portion 51 derives xr coordinates and yr coordinates of the second marker 72 in the robot coordinate system by using the coordinate conversion matrix. Here, since the second marker 72 is positioned at the center O20 of the image 20, when converting the coordinates of the center O20 of the image 20 in the robot coordinate system by using the coordinate conversion matrix, the xr coordinates and the yr coordinates of the second marker 72 in the robot coordinate system are derived.
Next, the control portion 51 rotates the sixth arm 16 only by an angle (for example, 30 degrees) determined in advance in a state where the rotation axis of the sixth arm 16 is maintained to be parallel to the zr axis. In a case where the hand 102 is rotated around the axial coordinates O6, there is a possibility that the second marker 72 moves to the outside of the image 20 from the center O20 of the image 20. Therefore, the angle by which the sixth arm 16 rotates is determined in advance in a range that the second marker 72 is positioned within the image 20 after the rotation. When rotating the sixth arm 16 in this manner, a state C where the second marker 72 rotates is achieved as the hand 102 rotates around the rotation axis parallel to the zr axis through the axial coordinates O6 (refer to
Next, the control portion 51 instructs the capturing to the second fixed camera 2, rotates the hand 102 around the axial coordinates O6, and as illustrated in
Next, the control portion 51 drives the robot arm 10 such that the second marker 72 moves again to the center O20 of the image 20 captured by the second fixed camera 2 (refer to
As described above, in the calibration (step S2) of the hand 102, only by moving the axial coordinates O6, for example, by a jog-feeding operation to a position at which the second marker 72 can be captured by the second fixed camera 2, it is possible to automatically derive and set the offset of the TCP with respect to the axial coordinates O6. Therefore, the setting of the offset of the robot 1 can be easily performed during a short period of time. In addition, even in a state where the coordinate system of the second fixed camera 2 and the coordinate system of the robot 1 are not calibrated, it is possible to automatically set the offset of the hand 102 with respect to the axial coordinates O6 of the robot arm 10.
Here, as described above, the hand 102 which is the end-effector is attached to the robot arm 10 which is the movable portion to be rotatable, and the axial coordinates O6 which is the standard point is positioned on the rotation axis A6 of the sixth arm 16 which is the member included in the robot arm 10.
Therefore, by performing the processing of acquiring the offset components (fifth work) described above, the distance between the hand 102 and the axial coordinates O6 is acquired, and thus, the robot 1 can perform the work with respect to the target 60 with higher accuracy.
Next, as illustrated in
As illustrated in
Hereinafter, the processing (step S31) of specifying the standard surface will be described with reference to the flowchart illustrated in
As illustrated in
Next, as illustrated in
Next, the control device 5 captures the second marker 72 by the second fixed camera 2 (step S313). At this time, the control device 5 performs the processing (focusing processing) of moving the calibration member 70 by driving the robot arm 10 such that a focal point of the second fixed camera 2 is adjusted (focused) to second marker 72. The processing may be performed by using the auto focus function of the second fixed camera 2. In addition, the focusing processing may be omitted.
Next, the control device 5 stores the image of the second marker 72 captured by the second fixed camera 2 in the storage portion 54 as “first image”, and the coordinates of the axial coordinates O6 in the robot coordinate system when the first image is captured is stored in the storage portion (step S314). Here, in the processing of specifying the standard surface in the second fixed camera 2 (step S31), the second marker 72 when the first image is captured is “first standard marker”.
Next, the control device 5 drives the robot arm 10, and translationally moves the calibration member 70 along the xr axis, the yr axis, and the zr axis in the robot coordinate system such that the second marker 72 is positioned at a position different from the position to which the second marker 72 is moved in step S312 on the image of the second fixed camera (step S315).
Next, the control device 5 captures the second marker 72 by the second fixed camera 2 (step S316).
Next, the shape and the size of the second marker 72 in the image captured by the second fixed camera 2 in step S316, and the shape and the size of the second marker 72 in the first image stored in the storage portion 54 in step S314, are compared with each other (step S317). In addition, it is determined whether or not a difference between the shape and the size of the second marker 72, and the shape and the size of the second marker 72 in the first image, is in a predetermined threshold value (step S318).
In a case where it is determined that the difference is in the predetermined threshold value (“YES” in step S318), the process moves to step S3110. Meanwhile, in a case where it is determined that the difference is not in the predetermined threshold value (“NO” in step S318), the calibration member 70 is moved by the driving of the robot arm so that the difference is to be in the predetermined threshold value (step S319). For example, the size (outer shape) of the second marker 72 illustrated by a two-dot chain line in
Next, when it is determined that the difference is in the predetermined threshold value, the control device 5 stores the image of the second marker 72 captured by the second fixed camera 2 in the storage portion 54 as “second image (n-the image)”, and stores the coordinate of the axial coordinates O6 in the robot coordinate system when the second image (n-th image) is captured in the storage portion 54 (step S3110). Here, in the processing of specifying the standard surface in the second fixed camera 2 (step S31), the second marker 72 when the second image is captured is “second standard marker”. In addition, when capturing the second image, the second marker 72 attached to the calibration member 70 gripped by the hand 102 is at a position different from the position when capturing the first image.
Next, it is determined whether or not the number n of the captured images is a predetermined number set in advance (here, n is an integral number, and is the number which satisfies the relationship of 3≦n) (step S3111). In a case where it is determined that the number is the predetermined number, the process moves to step S3112, and in a case where it is determined that the number is less than the predetermined number, the above-described step S315 to step S3110 are repeated until it is determined that the number is the predetermined number.
Here, in the embodiment, it is set in advance that the image is obtained until the number of the images becomes 3, that is, it is set to capture three images (first image, second image, and third image) by the second fixed camera 2 in advance. Therefore, in the embodiment, after capturing the second image by the second fixed camera 2, step S315 to step S3110 are performed one more time, the calibration member 70 is moved by the driving of the robot arm 10, the image of the second marker 72 captured by the second fixed camera 2 is stored in the storage portion 54 as “third image”, and the coordinates of the axial coordinates O6 in the robot coordinate system when the third image is captured are stored in the storage portion 54. Here, in the processing of specifying the standard surface in the second fixed camera 2 (step S31), the second marker 72 when the third image is captured is “third standard marker”. In addition, when capturing the third image, the second marker 72 attached to the calibration member 70 gripped by the hand 102 is at a position different from the position when capturing the first image and the position when capturing the second image, and is not on the same straight line. In addition, in the processing of specifying the standard surface in the second fixed camera 2 (step S31), it can be ascertained that the second marker 72 serves as “the first standard marker, the second standard marker, and the third standard marker”.
Next, when it is determined that the number n of images is the predetermined number, based on the coordinates of the axial coordinates O6 in n (three in the embodiment) robot coordinate systems stored in the storage portion 54, the control portion 51 acquires an origin point of a standard surface 81 parallel to the imaging element 21 (a plane which passes through the second markers 72 which are in a state of being disposed at three different locations) illustrated in
Above, the processing of specifying the standard surface (step S31) illustrated in
As described above, according to the control device 5, it is possible to acquire the posture of the standard surface 81 based on the images (the first image, the second image, and the third image) captured by the second fixed camera 2 (imaging portion). Therefore, similar to the related art, it is possible to omit the work of determining a contact state between a touch-up hand and a calibration tool (calibration member) by the worker. Therefore, it is possible to reduce variation caused by a human error or variation caused by the worker, and accordingly, it is possible to acquire the posture of the standard surface 81 with high accuracy. In addition, when the standard surface is acquired by bringing the touch-up hand into contact with the calibration tool similar to the related art, the posture of the acquired standard surface varies according to the material or the like of the calibration tool, and it is difficult to detect the posture of the standard surface with high accuracy. Meanwhile, in the embodiment, since the posture of the standard surface 81 is acquired based on the image captured by the second fixed camera 2, it is possible to acquire the posture of the standard surface 81 without coming into contact with the calibration member 70 (in a non-contact state). Therefore, for example, it is possible to acquire the posture of the standard surface 81 with high accuracy regardless of the material or the like of the calibration member 70.
In addition, according to the control device 5, since it is possible to acquire the posture of the standard surface 81 based on the image captured by the second fixed camera 2, it is possible to more easily and rapidly acquire the posture of the standard surface 81 than the related art.
In addition, as described above, in the embodiment, the standard surface 81 is acquired based on the coordinates of the axial coordinates O6 (predetermined part) in the robot coordinate system when each of the three images (the first image, the second image, and the third image) is respectively captured. Therefore, it can be said that the standard surface 81 is a surface including the axial coordinates O6. Therefore, as the robot 1 performs the work (for example, the work of determining whether or not the target 60 is accurately gripped by the hand 102) on the standard surface 81, the robot 1 can accurately perform the work.
In particular, as described above, in the embodiment, when capturing the three images, by performing the focusing processing, when the robot 1 performs each work of detecting, inspecting, and assembling the target 60 on the standard surface 81, the robot 1 can perform various types of work with higher accuracy.
In addition, in the above-described calibration (step S2) of the hand 102 which is the end-effector, the distance between the axial coordinates O6 and the tool center point TCP is known. Therefore, it is possible to acquire the surface including the tool center point TCP based on the distance and the standard surface 81 which is the surface including the axial coordinates O6.
In addition, in the embodiment, the processing of specifying the standard surface 81 based on the coordinates of the axial coordinates O6 (step S31) is performed, but the standard surface 81 may be specified based on the coordinates of the tool center point TCP, and the standard surface 81 may be specified based on another arbitrary part of the robot.
In addition, as described above, in the embodiment, based on the size of the second marker 72 in the first image, the size of the second marker 72 in the second image, and the size of the second marker 72 in the third image, the position and the posture of the standard surface 81 are acquired. Therefore, in the embodiment, when the position and the posture of the standard surface 81 are acquired based on the size of the second marker 72 in each image, it is possible to accurately acquire the posture of the standard surface 81.
In addition, the acquiring of the position and the posture of the standard surface 81 based on the size of the second marker 72 in each image, is the same as the acquiring of the posture of the standard surface 81, based on a distance (first distance) between the second marker 72 when the first image is obtained and the light receiving surface 211 (more specifically, imaging standard point O2) of the second fixed camera 2, a distance (second distance) between the second marker 72 when the second image is obtained and the light receiving surface 211 (imaging standard point O2), and a distance (third distance) between the second marker 72 when the third image is obtained and the light receiving surface 211 (imaging standard point O2). Therefore, according to the calibration method of the embodiment, it is possible to acquire the posture of the standard surface 81 based on the distance, such as the first distance, the second distance, and the third distance.
Next, as illustrated in
First, the control device 5 drives the robot arm 10, and moves the calibration member 70 such that each of the axial coordinates O6 is positioned at nine arbitrary standard points (virtual target points) which are arranged in a shape of lattice in the standard surface 81 acquired in the above-described step S31. In other words, the second marker 72 is moved to nine locations arranged in a shape of lattice. At this time, the control device 5 captures the second marker 72 by the second fixed camera 2 each time when the calibration member 70 is moved.
Here, all of the nine standard points are within a range (within an imaging region) of the image of the second fixed camera 2, and all of the intervals between the standard points adjacent to each other are equivalent to each other.
Next, based on the coordinates (components xa, ya, and ua) of the second marker 72 in the image coordinate system of the second fixed camera 2 based on the nine images, and the coordinates (components xr, yr, and ur) of the standard surface in the robot coordinate system acquired in the above-described step S31, the control device 5 acquires the correction parameter (coordinate conversion matrix) which converts the image coordinate of the second fixed camera 2 into the coordinate of the standard surface 81 in the robot coordinate system.
When the correction parameter acquired in this manner is used, it is possible to convert the position and the posture (specifically, components xa, ya, and ua) of the target 60 or the like captured by the second fixed camera 2 into the values (specifically, components xr, yr, and ur) in the robot coordinate system. In addition, the correction parameter is a value to which an inner parameter of the second fixed camera 2, such as distortion of the lens 22, is added.
In addition, in the embodiment, as described above, the correction parameter is acquired by using the nine standard points, but the accuracy of the calibration increases as the number of standard points used for acquiring the correction parameter increases.
Above, the calibration of the fixed camera illustrated in
Specifying of Standard Surface which Corresponds to Inspection Surface 621 of Inspection Stand 62 (Step S4)
Next, the control device 5 starts the specifying of the standard surface (virtual standard surface) which corresponds to the inspection surface 621 of the inspection stand 62 illustrated in
In addition, as illustrated in
Hereinafter, the specifying of the standard surface which corresponds to the inspection surface 621 of the inspection stand 62 (step S4) will be described in detail with reference to the flowchart illustrated in
First, the control device 5 drives the robot arm 10, and as illustrated in
Next, the control device 5 drives the robot arm 10, and moves the mobile camera 3 such that the first marker 71 attached to the calibration member 70 is positioned at the center part of the image of the mobile camera 3 (step S412).
Next, the control device 5 captures the first marker 71 by the mobile camera 3 (step S413). At this time, the control device 5 performs the processing (focusing processing) of moving the mobile camera 3 by driving the robot arm 10 such that the focal point of the mobile camera 3 is adjusted (focused) to the first marker 71. The processing may be performed by using the auto focus function of the mobile camera 3. In addition, the focusing processing may be omitted.
Next, the control device 5 stores the image of the first marker 71 captured by the mobile camera 3 in the storage portion 54 as “first image”, and stores the coordinates of the axial coordinates O6 in the robot coordinate system when the first image is captured in the storage portion 54 (step S414). Here, in specifying the standard surface which corresponds to the inspection surface 621 of the inspection stand 62 (step S4), the first marker 71 is “first standard marker”.
Next, the control device 5 drives the robot arm 10, and translationally moves the mobile camera 3 such that the second marker 72 is positioned at the center part of the image of the mobile camera 3 (step S415).
Next, the control device 5 captures the second marker 72 (n-th marker) by the mobile camera 3 (step S416).
Next, the shape and the size of the second marker 72 in the image captured by the mobile camera 3 in step S416, and the shape and the size of the first marker 71 in the first image stored in the storage portion 54 in step S414, are compared with each other (step S417). In addition, it is determined whether or not a difference between the shape and the size of the second marker 72 and the shape and the size of the first marker 71 is in a predetermined threshold value (step S418).
In a case where it is determined that the difference is in the predetermined threshold value (“YES” in step S418), the process moves to step S4110. Meanwhile, in a case where it is determined that the difference is not in the predetermined threshold value (“NO” in step S418), the mobile camera 3 is moved by the driving of the robot arm 10 so that the difference is to be in the predetermined threshold value (step S419).
Next, when it is determined that the difference is in the predetermined threshold value, the control device 5 stores the image of the second marker 72 (n-th marker) captured by the mobile camera 3 in the storage portion 54 as “second image (n-th image)”, and stores the coordinates of the axial coordinates O6 in the robot coordinate system when the second image (n-th image) is captured in the storage portion (step S4110). Here, in specifying the standard surface which corresponds to the inspection surface 621 of the inspection stand 62 (step S4), the second marker 72 is “second standard marker”.
Next, it is determined whether or not the number n of the captured images is a predetermined number set in advance (here, n is an integral number, and is the number which satisfies the relationship of 3≦n) (step S4111). In a case where it is determined that the number is the predetermined number, the process moves to step S4112, and in a case where it is determined that the number is less than the predetermined number, the above-described step S415 to step S4110 are repeated until it is determined that the number is the predetermined number.
Here, in the embodiment, it is set to capture three images (the first image, the second image, and the third image) by the mobile camera 3 in advance. Therefore, in the embodiment, after capturing the second image by the mobile camera 3, step S415 to step S4110 are performed one more time, the image of the third marker 73 captured by the mobile camera 3 is stored in the storage portion 54 as “third image”, and the coordinates of the axial coordinates O6 in the robot coordinate system when the third image is captured is stored in the storage portion 54. Here, in specifying the standard surface which corresponds to the inspection surface 621 of the inspection stand 62 (step S4), the third marker 73 is “third standard marker”.
Next, when it is determined that the number n of images is the predetermined number, based on the coordinate of the axial coordinates O6 in n (three in the embodiment) robot coordinate systems stored in the storage portion 54, the control portion 51 acquires an origin point of a standard surface 82 (virtual standard surface) parallel to the front surface 701 (a plane which passes through the first marker 71, the second markers 72, and the third marker 73) illustrated in
As described above, according to the control device 5, an effect similar to that of the processing of specifying the standard surface in the above-described calibration of the second fixed camera 2 (step S31) can be achieved. In other words, since the images (the first image, the second image, and the third image) captured by the mobile camera 3 (imaging portion) are used, it is possible to acquire the posture of the standard surface 82 without coming into contact with the calibration member 70, and accordingly, for example, it is possible to acquire the posture of the standard surface 82 with high accuracy regardless of the material or the like of the calibration member 70. In addition, it is possible to more easily and rapidly acquire the posture of the standard surface 82 than the related art.
In addition, as described above, in the embodiment, the position and the posture of the standard surface 82 are acquired based on the size of the first marker 71 in the first image, the size of the second marker 72 in the second image, and the size of the third marker 73 in the third image. Therefore, in the embodiment, when the position and the posture of the standard surface 82 are acquired based on the size of the second marker 72 in each image, it is possible to accurately acquire the posture of the standard surface 82.
In addition, the acquiring of the position and the posture of the standard surface 82 based on the size of the second marker 72 in each image, is the same as the acquiring of the posture of the standard surface 82, based on a distance (first distance) between the first marker 71 when the first image is obtained and the light receiving surface 311 (more specifically, imaging standard point O3) of the mobile camera 3, a distance (second distance) between the second marker 72 when the second image is obtained and the light receiving surface 311 (imaging standard point O3), and a distance (third distance) between the third marker 73 when the third image is obtained and the light receiving surface 311 (imaging standard point O3). Therefore, according to the calibration method of the embodiment, it is possible to acquire the posture of the standard surface 82 based on the distance of the first distance, the second distance, and the third distance.
Furthermore, as described above, by using the calibration member 70 to which the first marker 71, the second marker 72, and the third marker 73 of which the sizes are the same as each other are attached, the first image, the second image, and the third image are captured by the second fixed camera 2 such that the sizes of the first marker 71, the second marker 72, and the third marker 73 are the same as each other on the image. According to the capturing, even when a focal length or an angle of view of the mobile camera 3 is not known, it is possible to acquire the standard surface 82 which is parallel (orthogonal to the optical axis OA3 of the mobile camera 3) to the front surface 701.
In addition, the capturing of the first image, the second image, and the third image by the mobile camera 3 such that the sizes of the first marker 71, the second marker 72 and the third marker 73 are the same as each other, is the same as the acquiring of the posture of the standard surface 82 based on the first distance, the second distance, and the third distance which are the same as each other. Therefore, based on the first distance, the second distance, and the third distance which are the same as each other, even when the focal length or the angle of view of the mobile camera 3 is not known, it is possible to easily and rapidly acquire the standard surface 82 parallel to the front surface 701.
In addition, in the embodiment, each of the sizes of the first marker 71, the second marker 72, and the third marker 73 is the same as each other, but when the relationship between the sizes is known, the sizes may respectively vary. In this case, based on the relationship of the sizes of each of the first marker 71, the second marker 72, and the third marker 73, by acquiring the distance of the first distance, the second distance, and the third distance, it is possible to easily and rapidly acquire the standard surface 82 parallel to the front surface 701.
Next, the control device 5 starts the calibration of the mobile camera 3 on the inspection stand 62 (step S5) illustrated in
As illustrated in
Next, the processing of acquiring the offset components (step S51), that is, the fourth work of calculating the distance between the mobile camera 3 which is the first imaging portion and the axial coordinates O6 which is the standard point included in the robot 1, will be described with reference to the flowchart illustrated in
Here, as described above, on the design, the mobile camera 3 is offset and attached to the sixth arm 16 such that the optical axis OA3 is substantially parallel to the rotation axis A6 of the sixth arm 16. However, practically, a shift is generated from the offset component (the position and the posture of the mobile camera 3 with respect to the sixth arm 16) on the design. The shift is, for example, generated by an assembly error of the mobile camera 3 or an assembly error or the like of the imaging element 31 with respect to a housing of the mobile camera 3. Here, in the processing of acquiring the offset components (step S51), actual offset components (the position and the posture of the mobile camera 3 with respect to the sixth arm 16) are acquired.
In the following processing of acquiring the offset components (step S51), the offset components (Δx, Δy, Δz, Δu, Δv, and Δw) of the position of the imaging standard point O3 and the direction (posture) of the optical axis OA3 of the mobile camera 3 with respect to the axial coordinates O6 of the rotation axis member 161, are acquired.
In addition, in the embodiment, the offset components of the position of the imaging standard point O3 and the direction of the optical axis OA3 with respect to the axial coordinates O6 are acquired, but the location which becomes a standard when acquiring the offset components is arbitrary not being limited to the axial coordinates O6 and the imaging standard point O3.
As illustrated in
Next, the control device 5 drives the robot arm 10 such that the light receiving surface 311 of the mobile camera 3 faces the front surface 701 of the calibration member (step S512).
Next, the control device 5 verifies a degree of parallelization of the front surface 701 of the calibration member 70 with respect to the light receiving surface 311 of the mobile camera 3 (step S513). In addition, the control device 5 determines whether or not the degree of parallelization is in the predetermined threshold value (step S514).
As illustrated in
Next, when it is determined that the difference is in the predetermined threshold value, the control device 5 acquires offset components Δu, Δv, and Δw (step S515) from the difference between the components ur, vr, and wr of the axial coordinates O6 in the robot coordinate system when it is determined that the difference is in the threshold value, and the components ur, vr, and wr of the standard surface 82 in the robot coordinate system when the standard surface 82 is acquired in specifying the standard surface which corresponds to the inspection surface 621 of the inspection stand 62 (step S4). The offset components Δu, Δv, and Δw correspond to the offset components Δu, Δv, and Δw of the optical axis OA3 with respect to the axial coordinates O6.
Next, as illustrated in
Specifically, first, as illustrated in
Next, as illustrated in
Next, as illustrated in
It is ascertained that the movement of the mobile camera 3 and the sixth arm 16 which are in the third state via the second state from the first state, is the same as the rotation of the axial coordinates O6 (sixth arm 16) around a line segment which passes through the center O30 (imaging standard point O3) as a rotation center axis when the first state illustrated in
Next, as illustrated in
Next, as illustrated in
It is ascertained that the movement of the mobile camera 3 and the sixth arm 16 which are in the fifth state via the second state, the third state, and the fourth state from the first state, is the same as the rotation of the axial coordinates O6 around the line segment which passes through the center O30 (imaging standard point O3) as a rotation center axis when the first state illustrated in
According to the processing, it is possible to easily acquire the offset components Δx and Δy of the imaging standard point O3 with respect to the axial coordinates O6 with high accuracy.
In addition, as described above, in the embodiment, by performing the processing of transiting to the third state via the second state from the first state, the virtual offset components Δx′ and Δy′ are computed. In other words, by rotating the sixth arm 16 around the rotation axis A6 by an extremely small angle which is in a range where the second marker 72 is contained in the image 30 (in the imaging region) of the mobile camera 3, the virtual offset components Δx′ and Δy′ are computed. By performing the movement from the third state to the fourth state by using information of the virtual offset components Δx′ and Δy′, it is possible to surely give the second marker 72 to the inside of the image 30 in the fourth state.
Next, as illustrated in
As illustrated in
Here, in the embodiment, the focal length of the mobile camera 3 is acquired in advance, and is known. Therefore, the distance H can be computed, for example, from the focal length of the mobile camera 3, “pixel” which is the length of the pitches between the markers 75 in the image of the mobile camera 3, and “mm” which is the pitches between the actual markers 75.
In addition, the focal length of the mobile camera 3 can also be acquired, for example, from “pixel” which is the length of the pitches between the markers 75 on the image, and “mm” which is the pitches between the actual markers 75, before and after the operation in a case where the mobile camera 3 is moved only by an extremely small amount in the optical axis OA3 direction (zr direction) while photographing the marker 75 of the calibration member 70.
Next, as illustrated in a state B in
Next, as illustrated in a state C in
Next, the control device 5 acquires a correction amount ΔH for acquiring the actual offset component Δz of the mobile camera 3′ by the following equation (1).
Next, the control device 5 acquires the actual offset component Δz based on the correction amount ΔH and the offset component Δz on the design.
In this manner, it is possible to acquire the offset component Δz. According to the processing, it is possible to easily compute the offset component Δz.
Next, as illustrated in
Above, the processing of acquiring the offset (step S51) illustrated in
Next, as illustrated in
Here, the inspection surface 621 is parallel to the standard surface 82, and is at a position offset in the normal line direction (zr direction) of the standard surface 82. Therefore, in the processing of specifying the inspection surface (step S52), by determining the offset amount in the normal line direction (zr direction) with respect to the standard surface 82 of the inspection surface 621, it is possible to acquire the components xr, yr, zr, ur, vr, and wr of the inspection surface 621.
The offset amount in the normal line direction (zr direction) with respect to the standard surface 82 of the inspection surface 621 can be acquired based on the focal length of the mobile camera 3 acquired in advance, the number of pixels of the mobile camera 3 with respect to a value (actual size) of the pitches between the adjacent markers 75 of the calibration member 70, and the actual offset component described above.
By acquiring the position and the posture of the inspection surface 621 in the robot coordinate system in this manner, the robot 1 can perform the work with respect to the target 60 mounted on the inspection surface 621 with high accuracy.
Next, as illustrated in
Here, for example, the robot coordinate of the second marker 72 in the x-y plane of the standard surface 82 (or inspection surface 621) is instructed to the robot 1.
Specifically, first, the control device 5 aligns the optical axis OA2 of the mobile camera 3 to the z axis of the standard surface 82, based on the position of the imaging standard point O3 and the offset component in the direction of the optical axis OA3 with respect to the axial coordinates O6 computed by the above-described processing of acquiring the offset components (step S51). After this, the control device 5 translationally moves the mobile camera 3 in the plane parallel to the x-y plane of the standard surface 82 by the driving of the robot arm 10, and allows the second marker 72 to match the center of the image of the mobile camera 3. In addition, the control device 5 instructs the position of the imaging standard point O3 of the mobile camera 3 as the robot coordinate of the second marker 72 when the second marker 72 matches the center of the image of the mobile camera 3.
In addition, for example, by bringing an instruction tool (touch-up hand) of which the offset in the axial coordinates O6 is known into contact with the second marker 72, the position and the posture of the second marker 72 may be instructed to the robot 1. However, by capturing the image of the second marker 72 by the mobile camera 3, it is preferable to instruct the position and the posture of the second marker 72 to the robot 1, for example, since it is possible to instruct the second marker 72 with high accuracy regardless of the material or the like of the calibration member 70.
Processing of Acquiring Relationship between Image Coordinate System of Mobile Camera and Robot Coordinate System (Step S54)
Next, as illustrated in
The processing of acquiring the relationship between the image coordinate system of the mobile camera and the robot coordinate system (step S54) is similar to the above-described processing of acquiring the relationship between the image coordinate system of the fixed camera and the robot coordinate system (step S32) except that the standard surface is specified by using the calibration member 70 disposed on the inspection surface 621, and the second marker 72 (marker of which the robot coordinates are known) of the calibration member 70 installed on the inspection surface 621 is captured nine times while moving the mobile camera 3 to nine locations by driving the robot arm 10.
Therefore, when the processing of acquiring the relationship between the image coordinate system of the mobile camera 3 and the robot coordinate system (step S54) is finished, it is possible to acquire the correction parameter (coordinate conversion matrix) which converts the image coordinate of the second fixed camera 2 into the coordinate of the standard surface 82 in the robot coordinate system based on the coordinates (components xb, yb, and ub) of the second marker 72 in the image coordinate system of the mobile camera 3 based on the nine images, and the coordinates (components xr, yr, and ur) of the standard surface 82 in the robot coordinate system acquired by specifying the standard surface which corresponds to the inspection surface 621 of the inspection stand 62 (step S4).
When the correction parameter acquired in this manner is used, it is possible to convert the position and the posture (specifically, components xb, yb, and ub) of the target 60 or the like captured by the mobile camera 3 into a value (specifically, components xr, yr, and ur) in the robot coordinate system.
In addition, as described above, since the processing of acquiring the relationship between the image coordinate system of the mobile camera and the robot coordinate system (step S54) is substantially similar to the above-described processing of acquiring the relationship between the image coordinate system of the second fixed camera and the robot coordinate system (step S32), specific description (processing contents and effects) thereof will be omitted.
Next, as illustrated in
The calibration of the third fixed camera 9 (step S6) is similar to the above-described calibration of the second fixed camera 2 (step S3) except for performing of the calibration by the third fixed camera 9 instead of the second fixed camera 2. Therefore, even in the calibration of the third fixed camera 9, after performing the processing of specifying the standard surface, the processing of acquiring the relationship between the image coordinate system of the third fixed camera 9 and the robot coordinate system is performed (refer to
Therefore, when finishing the calibration of the third fixed camera 9 (step S6), it is possible to acquire the calibration parameter (coordinate conversion matrix) which converts the image coordinates of the third fixed camera 9 into the coordinates of the standard surface 81 in the robot coordinate system. Accordingly, it is possible to convert the position and the posture (specifically, components xc, yc, and uc) of the target 60 or the like captured by the third fixed camera 9 into the values (specifically, components xr, yr, and ur) in the robot coordinate system.
In addition, as described above, since the calibration of the third fixed camera 9 (step S6) is similar to the above-described calibration of the second fixed camera 2 (step S3) except for the performing of the calibration by the third fixed camera 9 instead of the second fixed camera 2, specific description (processing contents and effects) thereof will be omitted.
Above, the calibration of the imaging portion illustrated in
According to the calibration method of the imaging portion, since it is possible to acquire the postures of the standard surfaces 81 and 82 based on the images which are respectively captured by the second fixed camera 2, the third fixed camera 9, and the mobile camera 3, it is possible to omit the determination by the worker unlike the related art. Therefore, it is possible to reduce a human error or variation caused by the worker, and accordingly, it is possible to perform the calibration with high accuracy.
Above, the control device, the robot, and the robot system according to the invention are described based on the embodiments illustrated in the drawings, but the invention is not limited thereto, and configurations of each portion can be replaced with arbitrary configurations having similar functions. In addition, other arbitrary configuration elements may be added. In addition, the invention may be combined with two or more arbitrary configurations (characteristics) among each of the above-described embodiments.
In addition, in the embodiment, a case where 6-axis vertical articulated robot is used is described as an example, but the robot according to the invention may be a robot other than the vertical articulated robot, for example, a horizontal articulated robot. In addition, the horizontal articulated robot has a configuration in which a base; a first arm which is connected to the base, and extends in the horizontal direction; and a second arm which is connected to the first arm, and has a part that extends in the horizontal direction are provided. In addition, in a case where the robot according to the invention is the horizontal articulated robot, by performing the calibration as described above, for example, it is possible to ascertain whether or not the robot is installed in parallel to the work surface, or whether or not the fixed camera is installed such that the optical axis of the fixed camera is vertical to the surface including the xr axis and the yr axis in the robot coordinate system.
In addition, in the embodiment, the number of rotating axes of the robot arm of the robot is six, but in the invention, not being limited thereto, and the number of rotating axes of the robot arm may be, for example, two, three, four, five, seven, or more. In addition, in the embodiment, the number of arms of the robot is six, but in the embodiment, not being limited thereto, and the number of arms of the robot may be, for example, two, three, four, five, seven or more.
In addition, in the embodiment, the number of robot arms of the robot is one, but in the invention, not being limited thereto, and the number of robot arms of the robot may be, for example, two or more. In other words, the robot may be a robot having a plurality of arms, such as a double arm robot.
In addition, in the embodiment, two cameras, such as the fixed camera and the mobile camera which are the imaging portions are respectively configured to include the imaging element and the lens, but the imaging portion in the invention may have any configuration as long as the first marker, the second marker, and the third marker can be captured by the configuration.
In addition, in the embodiment, the calibration of the fixed camera is performed by using the calibration member, but in the calibration of the fixed camera, the calibration member may not be used. In a case where the calibration member is not used, for example, one marker may be attached to the tip end part (axial coordinates) of the robot arm, and the first marker may be used as the standard marker. In this case, one marker serves as “first standard marker, second standard marker, and third standard marker”.
In addition, in the embodiment, the second imaging portion is described as the second fixed camera, and the third imaging portion is described as the third fixed camera, but the second imaging portion may function as the third fixed camera, and the third imaging portion may function as the second fixed camera. In addition, in addition to the first imaging portion, the second imaging portion, and the third imaging portion, an imaging portion which is different from these may further be provided.
The entire disclosure of Japanese Patent Application No. 2016-144956, filed Jul. 22, 2016 is expressly incorporated by reference herein.
Number | Date | Country | Kind |
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2016-144956 | Jul 2016 | JP | national |