JPH03161223A - Fitting of work - Google Patents

Abstract

PURPOSE:To position a work with a high accuracy by determining the amount of dislocation between a present gripping position and a predetermined reference gripping position, based on the detection result by a three-dimensional sensor, and by compensating a teaching data regarding the movement of a work to a pair of pins provided at predetermined positions corresponding to the reference gripping position, using the amount of dislocation. CONSTITUTION:The gripping position of a work 102 to be gripped by a robot 105 is detected based on the photograph result of a two-dimensional sensor 109, and the gripping position is gripped by the robot, so as to bring the work 102 to the visual field of a three-dimensional sensor 110. The position of a pair of holes 103 is detected by the three-dimensional sensor 110, under the condition that the work is gripped by the robot, and the dislocation amount between a present gripping position and a predetermined reference gripping position is determined, based on the detection result of the position of the pair of holes by the three-dimensional sensor. A teaching data of the movement of the work to a pair of pins 107 provided on a predetermined fixed position in relation to the reference gripping position, is compensated using the dislocation amount, so as to fit the pair of holes to the pair of pins.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention involves fitting a pair of holes formed in a workpiece onto a pin provided at a fixed position using a robot to form a workpiece with high precision. Concerning a method for positioning. Conventional technologyCurrently, automation of assembly work using robots is progressing on various production lines. One of the methods for positioning and installing a workpiece in a fixed position with high precision is to form a pair of holes in the workpiece, and to install this pair of holes upright on an assembly stage provided at a fixed position. A method is known in which each pin is fitted onto a pair of pins. When multiple types of workpieces with different shapes are transported by a conveyor or other transport means, or when even one type of workpiece is transported in arbitrary positions and orientations, the entire image of the workpiece is captured using a two-dimensional sensor, for example. Take an image with a TV camera,
Based on the imaging results, it is necessary to use a robot to grasp the workpiece's gripping position. Problems to be Solved by the Invention In such prior art, a sensor with a somewhat wide field of view is required in order to capture the entire image of the workpiece. By setting the field of view of the sensor to be wide in this way, the resolution of the image must be coarsened. Therefore, the workpiece can be accurately gripped and a pair of holes formed in the workpiece can be connected to a pair of pins on the assembly stage. In reality, it was impossible to automate the fitting process. Therefore, such fitting work is currently performed by workers. An object of the present invention is to provide a method for fitting a workpiece in which a workpiece having a pair of holes can be automatically fitted into a pair of pins provided at a fixed position to position the workpiece with high precision. It is to provide. Means for Solving the Problems The present invention uses a two-dimensional sensor to photograph a workpiece having a pair of holes, which is transported by a transporting means, and grips it by a robot based on the imaging result of the two-dimensional sensor. Detect the gripping position of the workpiece to be held, grip the gripping position with the robot, bring the workpiece into the field of view of a 3D sensor capable of 3D detection, and with the workpiece gripped by the robot, open the holes in the pair of holes. The position is detected by a three-dimensional sensor, and based on the detection result of the position of the pair of holes by the three-dimensional sensor, the amount of deviation between the current gripping position and a predetermined reference gripping position is determined, and the predetermined fixation with respect to the reference gripping position is determined. Fitting of a workpiece, characterized in that teaching data for moving the workpiece to a pair of pins at a position is corrected by the amount of deviation, and the workpiece is moved by a robot so that the pair of holes fit into the pair of pins. It is a method. In addition, the present invention transports a workpiece having a pair of holes by a transporting means to a predetermined supply position, grips the transported workpiece with a robot, and uses a three-dimensional sensor capable of three-dimensional detection of the workpiece. With the workpiece brought into the visual field and gripped by the robot, the positions of the pair of holes are detected by a three-dimensional sensor, and based on the detection results of the positions of the pair of holes by the three-dimensional sensor, the current gripping position and the previously determined position are determined. Determine the amount of deviation from a predetermined reference gripping position, correct teaching data for moving the workpiece to the pair of pins at a predetermined fixed position corresponding to the reference gripping position by the amount of deviation, and align the pair of holes with the pair of pins. This is a workpiece fitting method characterized by moving the workpieces by a robot so that they fit together. Function According to the present invention, a two-dimensional sensor is used to image a workpiece having a pair of holes transported by a transporting means, and the gripping position of the workpiece to be gripped by a robot is detected. When multiple types of workpieces are transported by the transport means, based on the imaging results of the two-dimensional sensor,
It is also possible to identify the type of workpiece and detect the gripping position for each type of workpiece. The workpiece is gripped at the gripping position detected in this way, and the robot brings the workpiece into the field of view of a three-dimensional sensor capable of three-dimensional detection, and the position of the pair of holes is detected by the three-dimensional sensor. The two-dimensional sensor described above requires a wide field of view to capture the entire image of the workpiece in order to detect the gripping position of the workpiece, whereas the three-dimensional sensor only needs to detect the position of a pair of holes. , therefore 3
The three-dimensional position of each hole can be detected with high precision using a dimensional sensor. In this way, based on the detection results of the positions of the pair of holes by the three-dimensional sensor, the amount of deviation between the current gripping position and the predetermined reference gripping position is determined. The robot grips the workpiece at a reference gripping position, moves the workpiece to a pair of pins such as an assembly stage, which has a pair of holes in the workpiece at a predetermined fixed position, and fits the pins into the pair of holes. The teaching data to be moved to is stored in advance. Therefore, the teaching data is corrected by the amount of deviation, and in this way the workpiece is moved by the robot and the pair of
It is possible to automatically fit a hole into a pair of pins and position the workpiece with high precision.

Further, according to the present invention, when the supply position of the workpiece by the transport means is predetermined for each type of workpiece, the aforementioned two-dimensional sensor is omitted by teaching the robot the gripping position of the workpiece in advance. The fitting operation can be performed simply by detecting the hole position using a three-dimensional sensor. Even in times like these, three-dimensional sensors are essential.

The reason for this is that even when the workpiece supply position is determined in advance, there may be variations in the workpiece supply position, and the gripping position of the workpiece may shift due to shaking at the moment the robot grips the workpiece. Sometimes,
This is because there is a possibility that the robot will not be able to fit the hole in the workpiece to the pin.

Embodiment FIG. 1 is a perspective view of an embodiment of the present invention. A workpiece 102 is conveyed by a conveyor 100 in a horizontal conveyance direction 101 in an arbitrary position and orientation. The wire 2102 has a pair of holes 1 as shown in FIG.
03, and is capable of three-dimensional movement of a predetermined gripping position 104 of this workpiece 102.
Assembly stage 1 held in a fixed position by
In this way, the workpiece 102 can be automatically positioned on the assembly stage 106 with high precision. At the fixed position, there is a predetermined field of view 10 on the conveyor l00.
A two-dimensional sensor 109 realized by a television camera or the like is arranged to take two-dimensional images of 8. Further, a three-dimensional sensor 110 is arranged at the fixed position, and the field of view of this three-dimensional sensor 110 is indicated by reference numeral 111. Processing circuit 1 realized by a microcomputer etc.
12 is a two-dimensional sensor 109 and a three-dimensional sensor 110
The robot 105 is driven and controlled in response to the output from the robot 105.

The operation of processing circuit 112 is shown in FIG. Moving from step nl to step n2, the two-dimensional sensor 109
The workpiece 102 on the conveyor 100 is seen in the field of view 108.
The image is taken with In order to detect a constant gripping position W104 regardless of the position and orientation of the workpiece 102, the workpiece 710
2, the workpiece 102 is rotated by a predetermined angle θ clockwise from the longitudinal direction 114 of the workpiece 102 around its center of gravity 113,
A position separated by L from the center of gravity 113 as determined in advance is detected as the gripping position 104 in step n3. A vacuum pad 115 is provided at the working end of the robot 105, making it possible to grip many types of workpieces. This vacuum butt 115 allows the workpiece 102 to be moved away from the hole 103 of the workpiece 102 and the part where the nut is provided.
2 is defined as the gripping position 104, which is gripped by the vacuum pad 115 as described above.

In this way, the workpiece 102 is
When gripping the workpiece 102, the position of the center of gravity 113 of the workpiece 102 and the posture in the longitudinal direction 114 of the workpiece 102 are detected to determine the gripping position 104. Based on the information, the workpiece 102 is gripped by the vacuum butt 115 of the robot 105. Grasp. Next, in step n4, the workpiece 102 gripped by the robot 105 is placed in the field of view 1 of the three-dimensional sensor 110.
Move to 11 and bring. A pair of holes 103 formed in the workpiece 102 are captured with high precision by this three-dimensional sensor 110, and the center positions of these holes 103 are calculated and detected in step n6. The aforementioned two-dimensional sensor 109
has a wide field of view 108 in order to be able to image the entire image of the work 102 in the field of view 108, and therefore, although its accuracy is rough, the three-dimensional sensor 110 can capture the entire image of the workpiece 102 within a relatively narrow field of view 111. Enables highly accurate detection. In this way, the conveyor 100 is
After gripping the upper workpiece 102, the three-dimensional sensor 110 is used to detect the center position of each pair of holes 103 in the workpiece 102 gripped by the robot 105, so that the vacuum pad 115 of the robot 105 Even if the workpiece 102 is shaken at the moment the workpiece 102 is gripped, the center position of the hole 103 in the workpiece 102 can be detected with high accuracy in three dimensions. In step n7, the processing circuit 112 responds to the output of the three-dimensional sensor 110 and calculates the amount of deviation between the current gripping position of the workpiece 102 by the robot 105 and a predetermined reference gripping position. The robot 105 stores in advance workpiece movement teaching data for moving the workpiece 102 at its reference gripping position and fitting the hole 103 into the pin 107 that is set at a fixed position with high precision. Therefore, in step n8, the teaching data for moving the workpiece to the pair of pins 107 at a predetermined fixed position corresponding to the reference gripping position is corrected based on this amount of deviation. Based on the result of this correction, the robot 105 can
is moved in step n9 so that the pair of holes 103 are fitted with the pin i07. In this way conveyor 10
0 makes it possible to position the workpiece 102 transported at any position and orientation on the assembly stage 106 with high precision. When a plurality of types of workpieces having different shapes are conveyed by the conveyor 100, the type of the workpieces may be identified by the two-dimensional sensor 109 as described above, and the gripping position of each type of workpiece may be determined. As another embodiment of the present invention, when the supply position of the workpiece 102 conveyed by the conveyor 100 is determined for each type of workpiece 2102, the robot 105 may be taught the gripping position of the workpiece in advance. As a result, the robot can grip a workpiece located at a predetermined supply position at a predetermined gripping position of the workpiece, and automatically bring the gripped workpiece to the field of view 111 of the three-dimensional sensor 110. At this time, this three-dimensional sensor 110
By detecting with high precision the hole 103 of the workpiece 102 gripped by the vacuum pad 115 of the robot 105, even if there are variations in the workpiece supply position, it is possible to prevent vibrations from occurring at the moment the workpiece is gripped by the robot 105. However, by calculating the amount of deviation, the robot 1
05 can be used to position the pin 107 so that it fits into the hole 103 of the workpiece 102.

FIG. 4 is a perspective view showing a configuration for three-dimensionally capturing the hole 103 by the three-dimensional sensor 110. War 21
A perfectly circular hole 103 is formed facing the plane surface of 02. This hole 103 has a plurality of holes (two in this embodiment).
) is irradiated with slit light. Note that the camera and the two projectors 3.4 that emit slit light are integrated.

The slit beams are planes respectively indicated by reference numerals 5.6. The optical cutting line on the surface of the workpiece 102 is missing at the hole 103, and these end points are designated by reference marks A, B, C,
Each is indicated by D. The surface of the workpiece 102 is imaged by an industrial television camera 7. This camera 7 includes an imaging surface 8 of a charge storage device (abbreviated as CCD) and a lens 9 that images the surface of the workpiece 102 on the imaging surface 8. Work 1
The three-dimensional coordinate system of camera 7 is indicated by x, y, z, and the camera coordinate system of camera 7 (coordinate system set on the imaging surface of CCD) is indicated by Xc, Yc. The output from the camera 7 is the processing circuit 1
Given to 0. FIG. 5 is a block diagram showing the electrical configuration of the three-dimensional sensor 11O shown in FIG. The projector 3.4 is driven by a drive circuit 11.12. A television camera control 13 provided in the processing circuit 10 controls the camera 7.
providing a synchronization signal via line 14 to the charge storage element of;
As a result, the video signal obtained from the charge storage element is applied to the analog/digital conversion circuit 16 of the processing circuit 10 via the line 15 and converted into a digital value. The output from the analog/digital conversion circuit 16 obtained in this way is compared with a threshold value which is a discrimination level from the threshold setting device 17 in a comparator l8, and a binarized signal is obtained from a line 19. ．． This binary signal is stored in the frame memory 20. The contents of the memory 20 are given to the processing means 22 via the bus 21, and data can be transferred to an external processing circuit 112 via the communication controller 23. In one embodiment of the present invention having such a basic configuration, first, the center position of the hole 103 is measured (chapters [Chapters to U to be described later), and then the workpiece 10 is measured.
Measure the inclination of the surface, which is the plane of 2, that is, the attitude angle (
(Chapter M, described later), and furthermore, measure the distance between one surface of the workpiece 102 and the camera 7 (Chapter ■, described later). First, the measurement iF! of the center position of the circle of the hole 103 will be explained.
In the processing circuit 10, the process moves from step u1 to step u2 in FIG.
03, and measure the three-dimensional positions of the four end points A, BC, and D that are missing at the edge of the hole 103. ! , a method for measuring the three-dimensional positions of points A, B, C, and D using slit lights 5 and 6. As shown in FIG. 7, the slit light projector 3 and camera 7 are arranged, and one point P on the slit light plane 5 (this
are (X , Yc). The perspective transformation of camera 7 is shown in the first equation. In addition, the equation for the slit light plane 5 is shown in the second equation. a*X
+b*Y+Z=d
...+ (2) Therefore, the coordinates (X, Y, Z) of P in the object coordinate system can be found by solving the first and second equations simultaneously. Basically, the three-dimensional coordinates of all points on the slit light plane 5.6 can be determined. Before solving the simultaneous equations consisting of the first and second equations, the coefficient (
C++~Cz4. h, a, b, d) are determined in advance.
The method is shown below. (1) Regarding calibration of camera parameters. 01 of the first formula. ~C34 is called camera parameter? ．．
The camera parameters are the focal length of lens 9,
This value is determined depending on the position of the principal point of , the distance between the lens 9 and the light-receiving surface, that is, the imaging surface 8, etc. Since it is difficult to actually measure these values, they are determined using the following method.

Expanding the first equation and eliminating the coefficient h, C1 1*x+
cl ■Book y+c. , book z+c, 4-C31 book Xc*
X-C32*Xc*Y-C33pcsXc*Z-C3tDc
= 0... (3-1 >C21$X"C22 pieces Y"C2)*Z"C24-C31
Car Xc X-Cs 2 Xc*Y-C) 1
<*Xc= 0...(3-2). Therefore, the known 3 points of 6 points that are not on the same plane
The dimensional coordinates and the corresponding camera coordinates are shown in 3-1.
By substituting into Equation and Equation 3-2 and solving the 12-element simultaneous equations, 12 unknowns (C11 to C,,) are found. Here, in order to improve the accuracy of camera parameter calculation, we measure n points (n>6>) with known three-dimensional coordinates and find them using the least squares method. 12 yuan 2
n simultaneous equations are obtained. EneG=F...(4)? =[Xc+ Yc1・・・・・・・・・・・・・・・
......Xcn Yc. ] t...(6)G-
[C11C,2 Cl- C14 C21 C2■C
23 C21 C,,C32 C33] '...
・(7-1) However, C3→01...(
7-2) G = (Et*E)-1*E'*F by least squares method
...By calculating (8>), G is found. (2) Calculating the coefficients of the equation of the plane of the slit light. Substituting the three-dimensional positions of the known three points on the plane of the slit light into the second equation , a, b, and d are obtained, and by solving this, a, b, and d can be calculated.Here, to increase the accuracy, we will calculate the three-dimensional coordinates of known n points (n>3). Substitute into the second equation and solve the following 3-dimensional n simultaneous equations using the method of least squares.J*K=L...
(10), then K= (Jt*J)-'lJt*L
...(1l). (3) Calculating the three-dimensional coordinates of the feature points. Using the method described above, calculate C z"'-C 34. a , b ,
Once d has been determined, the three-dimensional coordinates of the feature point can be determined by combining the second and third equations and solving the following equation.

M*N=R...(
12) However, (below the margin) N=[X Y Z]t
...(14) R=[Cz C, <*Xc
C24 C*4*Vc d]t −(1
5-1) However, 0゜"=1 ... (1
5-2) From formula 12, N=M-'*R...
・(16)■, How to measure the center of a circle passing through points A, B, C, and D.

The center of the circle passing through points A, B, C, and D is (la>Located on a plane passing through 4 points A, B, C, and D.

(2a) The distances from each point A, B, C, and D are equal. It is determined from the two conditions 1a and 2a. (1) War 2
A plane P13 containing four points A, BC, and D, which is the surface of 102
, that is, calculation of the coefficients of the equation on the paper in FIG. 8 (step u3 in FIG. 6). The normal vector command of a plane including four points A, B, C, and D is such that Z command is large <, X, Y command and distance are small, so the equation of the plane is expressed by the following equation.

a+*X+bl*y+z=cL
- (17) Since the four points A, B, C, and D are points on this plane, we can calculate a, b, and d using the least squares method, or we can also calculate the three points A, B, and C. In this case, calculate a + + b l + d l using the inverse matrix, ignoring the precepts in the first row. (2) Calculating the coefficients of the equation for a plane in which two of the points A, B, C, and D have the same distance. Points (x, y, z) that are the same distance from each point can be expressed by the following formula. (x-x+)'+(y y+)2+(z-z,)2:r
2.-.(19) (i = 1 to 4) In order to calculate accurately, two points with a large distance from each other are used for calculation.Here, points A, B and points CD are used as bare points. Fig. 8 Referring to the plan view of , the points at equal distances from points A and B are expressed as follows (step u4 in FIG. 6).

-2Jx, *xx. ”-2'l'y+ *y+y,
'-:/kz. *z+z12=-2*x2*x+x2
'-2*y2*y+y2"-2*Z2*Z+22"
・'・(20-1)2(x,-x2)*x+
2(y+ yz)”y+2(z+ zz)*z”(
X+"X2") + (yl2Yz")+ (z12
222) - (20-2) This 20th
-2 formula, a2*x+b2*y+c2*z=d2- (20-3>
Put it as. Equation 20-3 is the equation for the plane Pll. Point C
, D are calculated in the same way (step u5 in FIG. 6).

2(x*-xJ*x+2(yz-y+)*y+2(zz
-z<)*z-(X*"x42)+(yi"3'4
Q + (23"Z4") ... (21-
1> Do this a. *x+b, *y+c. *z=d.
--- Put it as (21-2). Equation 21-2 is the equation for plane P12. (3) Calculation of the center O of the circle. The intersection of the three planes of Equation 17, Equation 20-3, and Equation 21-2 is the center of the circle. Therefore, the center coordinates of the circle (xcl
, ycl, zcl) can be found by solving the following simultaneous equations (step U6 in FIG. 6).

From this, ■, the attitude angle α around the X axis and the attitude angle β around the Y axis of the plane P13 are measured.

In Fig. 9 (1), the plane P13a is + around the X axis.
When angularly displaced by Δα and assumed the attitude of plane P13b,
The optical cutting line 26 of the slit light 5 on the plane P13a becomes the optical cutting line 27 on the plane P13b. camera 7
On the imaging plane 8, the image of the optical section line 26 with α=O is indicated by reference numeral 26a, and the image of the optical section line 27 after rotation thereof is indicated by reference numeral 27a. Further, as shown in FIG. 10 (1), when the plane P13c is angularly displaced by the angle Δβ around the Y axis and becomes the plane P13d, the light section line 28 on the plane P13c is the light section 4129 on the plane P13d. becomes. Therefore, on the imaging surface 8 of the camera 7, @28a of the light section line 28 becomes an image 29a of the light section line 29. In this way, the image 27a on the imaging surface 8. 29a, the plane P1
3a. Mutual angle Δα of P13b and planes P13c, P1
It can be found by calculating the angle Δβ of 3d. 9th
Δα. The definition of Δβ will be shown, and the method for determining the inclination of a plane will be specifically described with reference to FIGS. 11 to 13. (1) The attitude angle α of the target plane P13 around the X-axis shown in FIG. 12 and the attitude angle β of the target plane P13 around the Y-axis
In order to obtain, first, ① the equation of the light section line 30 of the horizontal slit light on the imaging surface 8 of the camera 7 is obtained in advance, and the equation of this light section line 30 and ① the above-described camera parameters obtained in advance. C. ~C34, ① An equation of a plane P14 passing through the optical cutting line 3o and the principal point of the lens 9 is determined (steps ml and m2 in FIG. 11). Also, ② Obtain the equation of the plane P15 of the slit light in advance (step m3 in Fig. 11). (2) By the equations ■■, ■ shown in the previous bar graph (1) and the camera parameters ■, planes P14, P15
Find the normal vector of each plane in P
2, P), and the direction vector of the intersection line 31 of planes P14P15 is 1 −= (1, t4, u4)
− (24), then l, and P2, P, are orthogonal, so P2・l<=O
...(25)Pco ・i! ．． = o

(26) From this, 14 is obtained (step m4 in Fig. 11).

(3> In the same way as shown in FIG.
If you also find the equation, the normal vectors of the planes P16 and P17 are P8 and P7, respectively, and the direction vector of the intersection line 33 is R*= (ss+ 1, us).
-(27), Ps'1s=O...
(28)P,・1. =O
...(29) As a result, l, is obtained (step m7 in Fig. l1). In FIG. 13, a plane P16 is a plane passing through the principal point of the lens 9, and P17 is a plane formed by the thrift light of the projector 3.

(4) Since the normal vector Po” (So, to, 1) ... <30) of the target surface P13 is orthogonal to l 4+ 12 8, P.-14=O P0・l,=0 As a result, P0 is found (1st ... (31) ... (32) Step m8 in Figure 1). Attitude angle α (X
(rotation angle around the axis) and β (rotation angle around the Y-axis) are determined by the following formula (step m9 in FIG. 11).

α=jan-' (to)
- (33) β=jan-l(so)
-(34)■, How to measure distance. As shown in FIG. 14, when measuring the distance between the plane P13e and the imaging surface 8 of the camera 7, this plane P13e
is displaced within a detectable range as shown by P13f and P13g, on the imaging surface 8, as shown in FIG.
5.36 are detected as images 34a, 35a, and 36a. In this way, the images 34a, 35a, 3 on the imaging surface 8
By detecting planes P13e and P13f
, PL3g can be measured.

This method will be explained in more detail with reference to FIGS. 15 and 16. (1) The equation of the optical axis of camera 7 is x=y=o...(
35>, and the distance d between the imaging plane 8 and the object plane P13 is defined as the Z coordinate of the intersection of the optical axis of the lens 9 of the camera 7 and the object plane P13.

If the coordinates of one point on the target plane P13 are found, the target plane P13
The equation of the plane of the target surface P13 can be determined from the normal vector. The point is plane P14P15. It is obtained as the intersection of P17, and the point is expressed as (Xo, 3'o+ zo
), the equation for the target plane P13 is so(x-xo)+to(y-yo)+1-(z-zo
)'=O ・(36) (steps r 1 , r 2 in FIG. 15) #(2) The distance ld is d=soXotoYo+Zo
...(37) (steps r3 and r4 in Figure 15). ■Measurement of surface position. Referring to FIG. 17, in measuring the position of surface 13,
A slit light 6 is emitted from a single light projector 4, and a camera 7
It is assumed that the optical axis 37 of is perpendicular to the X-Y plane of the object coordinate system. At this time, the three-dimensional position of point 39 on the intersection line 38 of the plane P13 to be measured and the slit light plane 6 is measured, and a certain portion of the Z-axis is taken as the surface position y1 (that is, the height). The present invention can not only measure the center position of the hole 103, but also calculate the area of the hole 103 and other physical quantities widely, and such modifications are easy for those skilled in the art. ．． Effects of the Invention As described above, according to the present invention, a two-dimensional sensor images a workpiece transported by a transporting means to detect the gripping position of the workpiece, and this gripping position is gripped by a robot to display the workpiece in three dimensions. The positions of the pair of holes are detected while the workpiece is being held by the robot in the field of view of the sensor, and based on the detection results by this three-dimensional sensor, the amount of deviation between the current gripping position and the predetermined reference gripping position is calculated. In this way, the teaching data for moving the workpiece to the pair of pins at a predetermined fixed position corresponding to the reference gripping position is corrected by the amount of deviation, and the robot is configured to fit the pair of holes into the pair of pins, respectively. Since the workpiece is moved by the , it becomes possible to automatically position the workpiece with high precision.

This eliminates the need for highly accurate detection over a wide field of view using a two-dimensional sensor. Furthermore, according to the present invention, when multiple types of workpieces are transported, it is also possible to identify the type of workpieces using a two-dimensional sensor and detect the gripping position of each type of workpiece. Furthermore, according to the present invention, when the workpiece supply position is determined for each type of workpiece, the aforementioned two-dimensional sensor can be omitted by teaching the robot the gripping position of the workpiece in advance. The ellipse is simplified by .

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the configuration of an embodiment of the present invention, FIG. 2 is a plan view of a workpiece 102, FIG. 3 is a flowchart for explaining the operation of the processing circuit 112, and FIG. A simplified perspective view of the three-dimensional sensor 110 of one embodiment, FIG. 5 is a block diagram showing the electrical configuration of the three-dimensional sensor 110 shown in FIG. 4, and FIG. 6 is a procedure for calculating the center position of the hole 103. 7 is a perspective view showing a method of three-dimensional position measurement of point P using slit light 5, FIG. 8 is a plan view of plane P13, and FIG. 9 is a diagram showing the definition of attitude angle α of the plane. , FIG. 10 is a simplified diagram showing the definition of the attitude angle β of the plane, FIG. 11 is a flow chart showing the procedure for measuring the attitude angle αβ, and FIGS.
Figure 14 is a simplified diagram showing the method for measuring the attitude angle α around the X-axis and the attitude angle β around the Y-axis in Figure 14. 15 is a flowchart showing the procedure for calculating the distance 1m1d in the plane, FIG. 16 is a diagram showing a simplified configuration for measuring the distance ld, and FIG. FIG. 2 is a simplified diagram showing the principle of measuring the position of the surface 13. FIG. 100... conveyor, 102... work, 103...
... hole, 104 ... gripping position, 105 ... robot, 107 ... pin, 109 ... two-dimensional sensor, 11
0... Three-dimensional sensor, 111... Field of view, 112...
・Processing circuit 3rd C Figure 4 Figure 5 Figure 8 Figure 9 Figure 10 Figure 11 Figure 13 Figure 14 Figure 15 Figure 17

Claims (2)

[Claims] (1) A two-dimensional sensor images a workpiece having a pair of holes transported by a transporting means, and based on the imaging results of the two-dimensional sensor, a robot determines the workpiece to be gripped. The gripping position is detected, the gripping position is gripped by a robot, and the workpiece is brought into the field of view of a three-dimensional sensor capable of three-dimensional detection.With the workpiece being gripped by the robot, the positions of the pair of holes are Detected by a dimensional sensor, and based on the detection result of the position of the pair of holes by the three-dimensional sensor, determines the amount of deviation between the current gripping position and a predetermined reference gripping position, and determines the predetermined fixed position with respect to the reference gripping position. The teaching data for moving the workpiece to the pair of pins in the above is corrected by the amount of deviation, and the workpiece is moved by the robot so that the pair of holes fit into the pair of pins. How to fit. (2) A workpiece having a pair of holes is transported by a transport means to a predetermined supply position, and the transported workpiece is gripped by a robot and a three-dimensional sensor capable of three-dimensional detection of the workpiece is installed. With the workpiece brought into the visual field and gripped by the robot, the positions of the pair of holes are detected by a three-dimensional sensor, and the current gripping position is determined based on the detection result of the position of the pair of holes by the three-dimensional sensor. and a predetermined standard gripping position, correct the teaching data for moving the workpiece to the pair of pins at the predetermined fixed position corresponding to the standard gripping position by the deviation amount, and adjust the pair of holes. A method for fitting a workpiece, comprising moving the workpiece by a robot so that the workpiece fits into the pair of pins.