JP2023088409A - Calibration method and robot system - Google Patents

Abstract

To provide a calibration method and robot system which can easily perform calibration.SOLUTION: A calibration method comprises: a movement step of arranging a body for calibration at a position that is a position different from a work area where a robot performs work to an object and is included in a field angle of a camera when driving a robot arm around one rotation shaft from the work attitude in which the robot arm is located in the work area, and arranging the body for calibration within the field angle of the camera by driving the robot arm in the work attitude around one rotation shaft; an imaging step of imaging the body for calibration with the camera; and a calibration step of performing calibration between the robot arm and the camera on the basis of an image obtained in the imaging step.SELECTED DRAWING: Figure 5

Description

The present invention relates to a calibration method and a robot system.

2. Description of the Related Art In the field of robots, there is a well-known technology for causing a robot to perform a task using the results of imaging by a camera attached to a robot arm. In this case, it is necessary to perform calibration for aligning the coordinate systems of the camera and the robot before work. For example, in Patent Document 1, for calibration, a jig having a calibration board is prepared, the calibration board attached to the jig is imaged by a camera, and the camera and the robot are connected based on the imaging result. A method for performing the calibration is described.

JP-A-8-210816

However, it is troublesome to separately prepare a jig for calibration.

A calibration method of the present invention provides a robot system having a robot having a base and a robot arm connected to the base and having at least one pivot shaft, and a camera arranged on the robot arm, wherein the A calibration method for calibrating a robot arm and the camera using a calibration object,
The robot arm is driven around one of the rotation axes from a working posture in which the robot arm is positioned within the work area at a position different from the work area where the robot works on the object. sometimes placing the calibration object at a position included within the angle of view of the camera;
a moving step of driving the robot arm in the working posture around one of the rotation axes to fit the calibration object within the angle of view of the camera;
an imaging step of imaging the calibration object with the camera;
and a calibration step of calibrating the robot arm and the camera based on the image obtained in the imaging step.

A robot system of the present invention comprises a robot comprising a base and a robot arm connected to the base and having at least one pivot shaft;
a camera disposed on the robot arm;
a controller;
The robot arm is driven around one of the rotation axes from a working posture in which the robot arm is positioned within the work area at a position different from the work area where the robot works on the object. a calibration object positioned at a position sometimes included within the angle of view of the camera;
The control device is
a moving step of driving the robot arm in the working posture around one of the rotation axes to fit the calibration object within the angle of view of the camera;
an imaging step of imaging the calibration object with the camera;
and a calibration step of calibrating the robot arm and the camera based on the image obtained in the imaging step.

1 is an overall configuration diagram of a robot system according to a preferred embodiment; FIG. It is a figure which shows the device structure of a three-dimensional shape measuring device. It is a figure which shows a striped pattern. FIG. 10 is a diagram showing a calibration object; FIG. 4 is a top view showing the arrangement of calibration objects; It is a flow chart which shows a calibration method. FIG. 4 is a diagram showing the coordinates of each point in images Di and Dj;

Hereinafter, the calibration method and robot system of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

FIG. 1 is an overall configuration diagram of a robot system according to a preferred embodiment. FIG. 2 is a diagram showing the device configuration of the three-dimensional shape measuring device. FIG. 3 is a diagram showing a stripe pattern. FIG. 4 is a diagram showing a calibration object. FIG. 5 is a top view showing the arrangement of calibration objects. FIG. 6 is a flow chart showing the calibration method. FIG. 7 is a diagram showing the coordinates of each point in the images Di and Dj.

The robot system 1 shown in FIG. 1 includes a robot 2, a three-dimensional shape measuring device 4 that measures the three-dimensional shape of an object W, and controls the driving of the robot 2 based on the measurement results of the three-dimensional shape measuring device 4. and a control device 5 . These units can communicate by wire or wirelessly. Communication may occur over a network such as the Internet. In such a robot system 1, the three-dimensional shape measuring device 4 measures the positions and orientations of the objects W piled up on the table T1, and the robot 2 picks up the objects W based on the measurement results. The object W thus carried is conveyed to the table T2, and the conveyed object W is aligned on the table T2. However, the work performed by the robot system 1 is not particularly limited.

-Robot 2-
The robot 2 is, for example, a robot that performs operations such as supplying, removing, transporting, and assembling precision equipment and parts constituting the same. However, the application of the robot 2 is not particularly limited. The robot 2 is a six-axis robot having six rotation axes O, and has a base 21 as a base fixed to the floor, ceiling, or the like, and a robot arm 22 connected to the base 21 .

The robot arm 22 includes a first arm 221 rotatably connected to the base 21 around a first rotation axis O1, and a first arm 221 rotatably coupled to the first arm 221 around a second rotation axis O2. The connected second arm 222, the third arm 223 connected to the second arm 222 so as to be rotatable about the third rotation axis O3, and the third arm 223 to the fourth rotation axis O4. a fourth arm 224 rotatably connected to the fourth arm 224; a fifth arm 225 rotatably connected to the fourth arm 224 about the fifth rotation axis O5; and a sixth arm 226 rotatably connected about a sixth rotation axis O6. An end effector 24 corresponding to the work to be executed by the robot 2 is attached to the tip of the sixth arm 226 . The end effector 24 of this embodiment is a hand that grips the object W. As shown in FIG.

The robot 2 also includes a first drive device 251 that rotates the first arm 221 with respect to the base 21, a second drive device 252 that rotates the second arm 222 with respect to the first arm 221, and a second drive device 252 that rotates the second arm 222 with respect to the first arm 221. A third driving device 253 for rotating the third arm 223 with respect to the arm 222 , a fourth driving device 254 for rotating the fourth arm 224 with respect to the third arm 223 , and a fourth driving device 254 for rotating the fourth arm 224 with respect to the fourth arm 224 . It has a fifth driving device 255 that rotates the fifth arm 225 and a sixth driving device 256 that rotates the sixth arm 226 with respect to the fifth arm 225 . Each of the first to sixth drive devices 251 to 256 has, for example, a motor, a controller that controls driving of the motor, and an encoder that detects the amount of rotation of the motor. The driving of the first to sixth driving devices 251 to 256 is independently controlled by the control device 5. FIG.

By using a 6-axis robot as the robot 2, the robot 2 can perform complex movements and can handle a wide range of tasks. However, the robot 2 is not particularly limited, and for example, the robot arm 22 may have one to five arms, or seven or more arms. Further, the robot 2 may be, for example, a SCARA robot (horizontal articulated robot), a dual-arm robot having two robot arms 22, or the like. Also, the robot 2 may be a self-propelled robot that is not fixed to the floor, ceiling, or the like.

－Three-dimensional shape measuring device－
The three-dimensional shape measuring device 4 measures the three-dimensional shape of the object W using phase shift interferometry. As shown in FIG. 2, the three-dimensional shape measuring device 4 acquires an image of a region including the object W, and a projector 41 that projects a fringe pattern PL formed by laser light LL onto the area including the object W. and a measurement unit 47 that controls the driving of these units and measures the three-dimensional shape of the object W based on the image acquired by the camera 46 .

Among these components, at least the projector 41 and the camera 46 are each fixed to the fifth arm 225 of the robot 2 . Also, the relative positional relationship between the projector 41 and the camera 46 is fixed. In addition, the projector 41 is arranged to irradiate the laser light LL toward the tip side of the fifth arm 225, that is, toward the end effector 24 side, and the camera 46 faces the tip side of the fifth arm 225 and emits the laser light LL. It is arranged so as to image an area including an irradiation range.

The position of the end effector 24 on the distal end side of the fifth arm 225 is maintained no matter how the arms 221 to 224 and 226 other than the fifth arm 225 move. Therefore, by fixing the projector 41 and the camera 46 to the fifth arm 225, the three-dimensional shape measuring device 4 can always emit the laser light LL to the tip side of the end effector 24, The tip side can be imaged. Therefore, regardless of the posture when the end effector 24 tries to grip the object W, that is, whatever posture the end effector 24 faces the object W, the stripe pattern PL is projected onto the object W in that posture. In addition, the object W can be imaged. Therefore, the three-dimensional shape of the object W can be measured more reliably.

However, the arrangement of the projector 41 and the camera 46 is not particularly limited, and they may be fixed to the first to fourth arms 221 to 224 or the sixth arm 226.

The projector 41 scans the object W with the laser light LL, thereby projecting a sinusoidal fringe pattern PL represented by brightness values as shown in FIG. As shown in FIG. 2, the projector 41 includes a light source 42 that emits a laser beam LL, an optical system 43 that includes a plurality of lenses through which the laser beam LL emitted from the light source 42 passes, and a laser beam that has passed through the optical system 43. and an optical scanning unit 44 that scans the object W with the light LL. As the light source 42, for example, a semiconductor laser such as a vertical cavity surface emitting laser (VCSEL) or an external cavity vertical surface emitting laser (VECSEL) can be used.

The optical system 43 includes a condensing lens 431 that converges the laser light LL emitted from the light source 42 near the object W, and directs the laser light LL condensed by the condensing lens 431 in a direction parallel to the swing axis J. That is, it has a line-shaped rod lens 432 extending in the depth direction of the paper surface of FIG.

The light scanning unit 44 has a mirror 441 that rotates around the swing axis J. By reflecting the laser light LL on the mirror 441, the line-shaped laser light LL is scanned in a plane.

The projector 41 is not particularly limited as long as it can project the stripe pattern PL onto the object W. FIG. For example, instead of the rod lens 432, a MEMS or a galvanomirror may be used to diffuse the linear laser light LL into a line. That is, the two optical scanning units 44 may be used to two-dimensionally scan the laser light LL. Alternatively, for example, one gimbal-type MEMS having two degrees of freedom may be used to two-dimensionally scan the laser light LL. Further, the projector 41 may be, for example, a liquid crystal projector other than the optical scanning projector.

The measurement unit 47 measures the three-dimensional shape of the object W using the phase shift method. According to the phase shift method, since the depth of the object W can be measured with high accuracy, the three-dimensional shape of the object W can be measured with high accuracy. It should be noted that although the measurement unit 47 is included in the control device 5 in this embodiment, the present invention is not limited to this.

-Control device-
The control device 5 measures the three-dimensional shape of the object W based on a plurality of images captured by the camera 46, and independently controls the driving of the arms 221 to 226 and the end effector 24 based on the measurement results. do. Note that the measurement of the three-dimensional shape of the object W is performed by the measurement unit 47 . Such a control device 5 is composed of, for example, a computer, and has a processor for processing information, a memory communicably connected to the processor, and an external interface. The memory stores various programs that can be executed by the processor, and the processor reads and executes the various programs stored in the memory.

The configuration of the robot system 1 has been described above. Next, a method for measuring a three-dimensional shape and a method for calibrating the three-dimensional shape measuring device 4 will be described in order.

- Three-dimensional shape measurement method -
The control device 5 drives the projector 41 to project a sinusoidal fringe pattern PL represented by brightness values onto the object W four times while shifting the phase by π/2. The projected object W is imaged by the camera 46 . Then, the control device 5 generates 3D point cloud data based on the four images captured by the camera 46, and performs three-dimensional shape measurement of the object W based on the generated 3D point cloud data.

However, the shift width of the phase of the fringe pattern PL and the number of times of projection are not particularly limited. Further, in the present embodiment, the "single-period phase shift method" using a fringe pattern PL having one period is used, but the present invention is not limited to this, and the "multi-period phase shift method" using a plurality of fringe patterns having different periods is used. shift method" may be used.

In the phase shift method, the longer the fringe pattern period, the wider the measurement range, but the lower the depth resolution. Therefore, by using the multi-cycle phase shift method, it is possible to achieve both a wide measurement range and high depth resolution. The multi-cycle phase shift method is not particularly limited. For example, it may be a method of measuring a plurality of times in each cycle in a plurality of cycles, or a method of measuring a different number of times in each cycle in a plurality of cycles. .

-Robot 2 calibration method-
When the robot system 1 is shipped, the coordinate systems of the three-dimensional shape measuring device 4 and the robot 2 are aligned, that is, calibration (hereinafter simply referred to as "calibration") is performed to make the relative positional relationship known. Due to various factors such as the use environment of the robot system 1, secular change, application of external force such as collision, etc., the relative positional relationship may deviate from that at the time of shipment. If the relative positional relationship deviates, the work accuracy of the robot 2 deteriorates, so in such a case, recalibration is required. Therefore, even if the robot system 1 is installed in a facility such as a factory after shipment, it is preferable that the calibration can be easily performed in that state. This calibration method will be described in detail below.

Prior to the calibration method, the calibration object 9 will be briefly described. The calibration object 9 is plate-shaped, and on one principal surface thereof, as shown in FIG. 4, a plurality of black dots 91 are arranged in a matrix. has dot patterns DP arranged at equal pitches. Such a calibration object 9 is also called a calibration board. By using the calibration object 9 having such a dot pattern DP, the three-dimensional shape measuring device 4 and the robot 2 can be easily calibrated. Note that the position (coordinates) of the calibration object 9 and the pitch P between the adjacent black dots 91, ie, the center-to-center distance, are known and stored in the control device 5 in advance.

Such a calibration object 9 is placed at a location different from the work area Ew of the robot 2, as shown in FIG. The work area Ew refers to a space in which the robot 2 performs a predetermined work, and in the case of this embodiment, it is an area indicated by a dashed line. The work area Ew consists of a space in which the end effector 24 is positioned above the table T1 to grip the object W, and a space in which the end effector 24 is positioned above the table T2 to release the object W. and including. The work area Ew can be freely set by the user based on the contents of work, safety margins, and the like.

By arranging the calibration object 9 outside the work area Ew in this way, the calibration object 9 does not interfere with the work. Further, the calibration object 9 can be permanently installed because it does not interfere with the work. That is, it can remain stationary. Therefore, it becomes unnecessary to attach/detach the calibration object 9 for each calibration, and the calibration time can be shortened. In addition, since the position of the calibration object 9 is maintained, substantially no error occurs in each calibration, and the accuracy of calibration is enhanced. In addition, contact between the calibration object 9 and the robot 2 can be prevented, and deterioration in calibration accuracy due to scratches, damage, dirt, adhesion of foreign matter, etc. can be effectively suppressed.

Further, the calibration object 9 is arranged at a position included in the angle of view of the camera 46 when the robot arm 22 is driven around one rotation axis O from the working posture in which the robot arm 22 is positioned within the work area Ew. It is Therefore, it is possible to smoothly shift from the working posture to the calibration work.

The "single rotation axis O" is not particularly limited, and can be arbitrarily selected from the first to sixth rotation axes O1 to O6. In particular, in this embodiment, the first rotation axis O1 is selected as the "single rotation axis O". The first rotation axis O<b>1 is the rotation axis O of the robot arm 22 closest to the proximal end. Therefore, the entire robot arm 22 can be largely moved by rotating the first rotating shaft O1. Therefore, a wide area in which the calibration object 9 can be arranged can be secured, and the degree of freedom in arranging the calibration object 9 is improved.

In particular, in the present embodiment, the home position HP at the start of work is the working posture, and the position included in the angle of view of the camera 46 when the robot arm 22 is driven around the first rotation axis O1 from this working posture. , the calibration object 9 is arranged. Therefore, it becomes easier to perform calibration before starting work, and subsequent work can be performed with high accuracy. However, which posture is used as the work reference is not particularly limited, and can be appropriately set, for example, in relation to the arrangement possible area of the calibration object 9 . For example, it may be a predetermined posture other than the home position included during the gripping motion, a predetermined posture included during outward movement, or a predetermined posture included during backward movement.

The configuration of the calibration object 9 has been described above. Next, a calibration method will be described. As shown in FIG. 6, the calibration method includes a moving step S1 in which the robot arm 22 in the working posture is driven around the first rotation axis O1 to fit the calibration object 9 within the angle of view of the camera 46; and a calibration step S3 for performing calibration based on the image obtained in the imaging step S2.

<<Movement step S1>>
In order to start work, the control device 5 controls the driving of the robot 2 to bring the robot arm 22 to the home position HP. Next, the control device 5 controls the driving of the robot 2 to rotate the robot arm 22 around the first rotation axis O<b>1 to bring the calibration object 9 within the angle of view of the camera 46 . In addition, in the configuration of FIG. 6, the robot arm 22 is rotated clockwise about the first rotation axis O1 by 90 degrees.

<<imaging step S2>>
The control device 5 drives the robot arm 22 to change the position and posture of the camera 46 and takes a plurality of images of the calibration object 9 with the camera 46 . Thereby, it is possible to obtain a plurality of images D of the calibration object 9 in different directions and sizes.

<<Calibration step S3>>
The control device 5 first selects two arbitrary images from the plurality of images D obtained in the imaging step S2. In the following, for convenience of explanation, two arbitrary selected images D are assumed to be Di and Dj. Next, based on the image Di, the control device 5 calculates coordinates Ai from the origin G0 of the robot 2 to the tip G1 of the robot arm 22 and coordinates from the reference point G2 of the calibration object 9 to the reference point G3 of the camera 46. Bi and . The origin G0 of the robot 2 is set at the center of the base 21, the tip G1 of the robot arm 22 is set at the center of the tip surface of the sixth arm 226, and the reference point G2 of the calibration object 9 is set at the dot pattern DP , and the reference point G3 of the camera 46 is set at the center of the imaging plane. However, where these points G0 to G3 are set is arbitrary and not particularly limited.

The coordinates Ai can be obtained, for example, from the posture of the robot arm 22 when the image Di was acquired. The posture of the robot arm 22 can be determined based on the output from the encoders of the drive devices 251-256. On the other hand, the coordinates Bi can be obtained from the image Di. For example, the control device 5 first binarizes the image Di, calculates the centroid of the black point 91, and obtains the depth of each pixel of the image Di. Here, as described above, the coordinates and pitch P of the calibration object 9 are known. Therefore, the control device 5 next obtains the coordinates Bi based on the obtained depth of each pixel, the coordinates of the calibration object 9, and the pitch P. FIG.

Similarly to the coordinates Ai and Bi, the control device 5 calculates the coordinates Aj from the origin of the robot 2 to the tip of the robot arm 22 and the coordinates Bj from the calibration object 9 to the camera 46 based on the image Dj. demand.

As shown in FIG. 7, when the inner product of Ai, Aij, and Aj ⁻¹ (the inverse matrix of Aj) returns to the origin of Ai in order, Ai·Aij·Aj ⁻¹ =I (where I is the identity matrix) holds, and this The following formula (1) is derived from the formula. Similarly, the inner product ^of Bi, Bij, and Bj ⁻¹ (inverse matrix of Bj) returns to the origin of Bi. Homogeneous coordinates expressing both rotation and parallel movement of coordinates are used for coordinate calculation.

Further, when the coordinate from the tip of the robot arm 22 to the camera 46 is X, the inner product of Aij ^, X, Bij ⁻¹ , and X ⁻¹ returns to the origin of Aij. ⁻¹ =I holds, and the following equation (3) is derived from this equation.

The control device 5 prepares a plurality of equations (3) by changing combinations of the images Di and Dj, and obtains the coordinate X from the tip of the robot arm 22 to the camera 46 based on these multiple equations (3). . Then, calibration is performed based on the obtained coordinate X. That is, the coordinate systems of the camera 46 and the robot 2 are aligned. It should be noted that the greater the number of equations (3), the more accurate calibration can be performed. Therefore, in the present embodiment, 81 images D are acquired, and the coordinate X is obtained based on 3240 ( ₈₁ C ₂ ) equations (3).

The calibration method has been described above. By arranging the calibration object 9 outside the work area Ew in this way, the calibration object 9 does not interfere with the work, so the calibration object 9 can be permanently installed. Therefore, it becomes unnecessary to attach/detach the calibration object 9 for each calibration. In addition, since the position of the calibration object 9 is maintained, substantially no error occurs in each calibration, and the accuracy of calibration is enhanced. In addition, contact between the calibration object 9 and the robot 2 can be prevented, and deterioration in calibration accuracy due to scratches, adherence of foreign matter, or the like can be effectively suppressed. In addition, if the robot arm 22 is driven around one rotation axis O from the working posture, the calibration object 9 can be kept within the angle of view of the camera 46, so that the working posture can be smoothly shifted to the calibration work. can do. From the above effects, according to the calibration method described above, calibration can be performed easily, with high accuracy, and in a short period of time.

The robot system 1 and the calibration method have been described above. As described above, the calibration method includes the robot 2 having the base 21 as a base and the robot arm 22 connected to the base 21 and having at least one rotation axis O, and the camera 46 arranged on the robot arm 22. and a calibration method for calibrating the robot arm 22 and the camera 46 using the calibration object 9 in the robot system 1 having a work area Ew in which the robot 2 works on the object W; is a different position, and is a position included in the angle of view of the camera 46 when the robot arm 22 is driven around one rotation axis O from the work posture in which the robot arm 22 is located within the work area Ew. A moving step S1 in which the object 9 is arranged and the robot arm 22 in the working posture is driven around one rotation axis O to fit the calibration object 9 within the angle of view of the camera 46, and the camera 46 moves the calibration object 9. It includes an imaging step S2 for imaging, and a calibration step S3 for calibrating the robot arm 22 and the camera 46 based on the image D obtained in the imaging step S2.

By arranging the calibration object 9 outside the work area Ew in this way, the calibration object 9 does not interfere with the work, so the calibration object 9 can be permanently installed. Therefore, it becomes unnecessary to attach/detach the calibration object 9 for each calibration. In addition, since the position of the calibration object 9 is maintained, substantially no error occurs in each calibration, and the accuracy of calibration is enhanced. In addition, contact between the calibration object 9 and the robot 2 can be prevented, and deterioration in calibration accuracy due to scratches, adherence of foreign matter, or the like can be effectively suppressed. In addition, if the robot arm 22 is driven around one rotation axis O from the working posture, the calibration object 9 can be kept within the angle of view of the camera 46, so that the working posture can be smoothly shifted to the calibration work. can do. From the above effects, according to the calibration method described above, calibration can be performed easily, with high accuracy, and in a short period of time.

Further, as described above, the robot arm 22 has the first arm 221 that is connected to the base 21 and that rotates about the first rotation axis O1 with respect to the base 21. The robot arm 22 is driven around the driving axis O1. The first rotation axis O<b>1 is the rotation axis O of the robot arm 22 closest to the proximal end. Therefore, the entire robot arm 22 can be largely moved by rotating the first rotating shaft O1. Therefore, a wide area in which the calibration object 9 can be placed can be secured, and the degree of freedom in arranging the calibration object 9 is improved.

Further, the robot arm 22 has six rotation axes O as described above. As a result, the rotation axis O to be rotated in the moving step S1 can be arbitrarily selected from among the six, so that the degree of freedom in arranging the calibration object 9 increases.

Further, as described above, the robot system 1 includes a robot 2 including a base 21 as a base and a robot arm 22 connected to the base 21 and having at least one rotation axis O, and a camera arranged on the robot arm 22. 46, the control device 5, and a position different from the work area Ew where the robot 2 works on the target object W, and the robot arm 22 is positioned within the work area Ew by one rotation axis. and a calibration object 9 arranged at a position included within the angle of view of the camera 46 when the robot arm 22 is driven around O. Then, the control device 5 moves the robot arm 22 in the working posture around one rotation axis O to move the calibration object 9 within the angle of view of the camera 46 in a moving step S1, and moves the calibration object 9 with the camera 46. and a calibration step S3 for calibrating the robot arm 22 and the camera 46 based on the image D obtained in the imaging step S2.

By arranging the calibration object 9 outside the work area Ew in this way, the calibration object 9 does not interfere with the work, so the calibration object 9 can be permanently installed. Therefore, it becomes unnecessary to attach/detach the calibration object 9 for each calibration. In addition, since the position of the calibration object 9 is maintained, substantially no error occurs in each calibration, and the accuracy of calibration is enhanced. In addition, contact between the calibration object 9 and the robot 2 can be prevented, and deterioration in calibration accuracy due to scratches, adherence of foreign matter, or the like can be effectively suppressed. In addition, if the robot arm 22 is driven around one rotation axis O from the working posture, the calibration object 9 can be kept within the angle of view of the camera 46, so that the working posture can be smoothly shifted to the calibration work. can do. From the above effects, according to the calibration method described above, calibration can be performed easily, with high accuracy, and in a short period of time.

Although the calibration method and robot system of the present invention have been described above based on the illustrated embodiments, the present invention is not limited to this, and the configuration of each part may be any configuration having similar functions. can be replaced with Also, other optional components may be added to the present invention.

Reference Signs List 1 robot system 2 robot 21 base 22 robot arm 221 first arm 222 second arm 223 third arm 224 fourth arm 225 fifth arm 226 Sixth arm 24 End effector 251 First driving device 252 Second driving device 253 Third driving device 254 Fourth driving device 255 Fifth driving device 256 Sixth driving device , 4... three-dimensional shape measuring device, 41... projector, 42... light source, 43... optical system, 431... condenser lens, 432... rod lens, 44... optical scanning unit, 441... mirror, 46... camera, 47... measurement Part, 5... Control device, 9... Calibration object, 91... Black point, Ai... Coordinates, Aj... Coordinates, Aij... Coordinates, Bi... Coordinates, Bj... Coordinates, Bij... Coordinates, D... Image, Di... Image, Dj ... image, DP ... dot pattern, Ew ... work area, G0 ... origin, G1 ... tip, G2 ... reference point, G3 ... reference point, HP ... home position, J ... oscillation axis, LL ... laser beam, O ... rotation Driving shaft, O1... 1st rotation axis, O2... 2nd rotation axis, O3... 3rd rotation axis, O4... 4th rotation axis, O5... 5th rotation axis, O6... 6th rotation axis , P... Pitch, PL... Stripe pattern, S1... Moving step, S2... Imaging step, S3... Calibration step, T1... Table, T2... Table, W... Object, X... Coordinates

Claims (4)

A robot system comprising a robot having a base and a robot arm connected to the base and having at least one pivot axis, and a camera arranged on the robot arm, wherein the robot arm and the camera are calibrated. A calibration method for calibrating using an object for
The robot arm is driven around one of the rotation axes from a working posture in which the robot arm is positioned within the work area at a position different from the work area where the robot works on the object. sometimes placing the calibration object at a position included within the angle of view of the camera;
a moving step of driving the robot arm in the working posture around one of the rotation axes to fit the calibration object within the angle of view of the camera;
an imaging step of imaging the calibration object with the camera;
and a calibration step of calibrating the robot arm and the camera based on the image obtained in the imaging step. The robot arm has a first arm that is connected to the base and rotates about a first rotation axis with respect to the base,
2. The calibration method according to claim 1, wherein in said moving step, said robot arm is driven around said first rotation axis. 3. The calibration method according to claim 1, wherein said robot arm has six said rotation axes. a robot comprising a base and a robot arm connected to the base and having at least one pivot axis;
a camera disposed on the robot arm;
a controller;
The robot arm is driven around one of the rotation axes from a working posture in which the robot arm is positioned within the work area at a position different from the work area where the robot works on the object. a calibration object positioned at a position sometimes included within the angle of view of the camera;
The control device is
a moving step of driving the robot arm in the working posture around one of the rotation axes to fit the calibration object within the angle of view of the camera;
an imaging step of imaging the calibration object with the camera;
and a calibration step of calibrating the robot arm and the camera based on the image obtained in the imaging step.

Images