JP2000071190A - Work transfer system - Google Patents

Abstract

(57) [Summary] A cycle time can be shortened and a positional deviation of a conveyed work can be accurately corrected. A detection unit is provided on a robot body of a work transfer robot, and a vertical side of the work is placed on a telescopic hand and conveyed along a trajectory of the work. Upper two points P1 and P2 and one point P3 on the side
Detect the position of. Based on this detection result, the robot controller 9 calculates the positional deviation between the regular position of the work 2a and the current work 2a, and moves the hand H based on the calculated result to determine the positional deviation of the work 2a. Correct during transport. The displacement of the work 2a is represented by the rotation amount of the work 2a and the movement amount of the vertex of the work 2a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the transfer of a work such as a glass substrate by using a work transfer device such as a work transfer robot. More particularly, the present invention relates to a work transfer system capable of satisfying both the reduction of the cycle time for transferring the work and the reliability.

[0002]

2. Description of the Related Art Conventionally, there is a work transfer system in which a work such as a glass substrate to be processed is taken out of a predetermined cassette using a work transfer robot and stored in another cassette or the like. When transferring the work, if the position of the work placed on the hand of the work transfer robot is shifted,
In such a case, the work cannot be accurately set at a predetermined position in the cassette at the storage destination, and in the worst case, the work cannot be stored in the cassette and the work may be damaged.

For this reason, for example, Japanese Patent Application Laid-Open No. Hei 9-162257
In the apparatus for transferring a thin substrate described in Japanese Patent Application Laid-Open Publication No. H11-207, two distance sensors for detecting the positional deviation and the angular deviation of the glass substrate in the front-rear direction are provided on the hand, and the position for detecting the horizontal positional deviation of the glass substrate is provided. A detection sensor is provided in the main body of the work transfer robot, whereby the position of the glass substrate placed on the hand is corrected and the transfer control of the glass substrate is accurately performed.

[0004]

However, in order to correct the position of the glass substrate by the thin substrate transfer device described in Japanese Patent Application Laid-Open No. 9-162257, first, the two substrates provided on the hand are required. Using a distance sensor,
Before placing the glass substrate on the hand, the rotation deviation of the glass substrate and the positional deviation of the distance sensor and the vertical direction (Y direction) are detected based on the detection distance between the glass substrate and the hand. When the transfer robot moves left and right on the traveling rail, the position shift of the glass substrate in the left and right direction is detected.
That is, in the conventional transfer device, the hand has to be moved to detect the glass substrate, and the hand has to take the detection posture. Therefore, there is a problem that the cycle time for transporting the glass substrate becomes longer due to the position detection processing before the transport of the glass substrate.

Further, when the transfer robot moves on the traveling rail, the speed becomes high. Therefore, even though the position has been corrected once, the position of the glass substrate placed on the hand due to vibration during the movement or the like is changed. There is a problem that the reliability may be reduced because of the possibility of the displacement.

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the above problems, to shorten the cycle time, and to provide a work transfer apparatus capable of accurately correcting the positional deviation of a transferred work.

[0007]

According to a first aspect of the present invention, a work having at least two sides intersecting on an extension of the work is placed on a hand of a work transfer device, and a positional shift of the work is detected. In the work transfer system that controls the transfer of the work based on the detection result, at least three works on two sides of the work placed on the hand are controlled.
Detecting means for detecting a position of a point; calculating a rotational shift amount and a parallel shift amount from a normal position of the work based on at least three points detected by the detecting means; It is characterized in that transport control is performed.

In the first invention, at least three points can be detected at the same time, and the rotational displacement and the parallel displacement of the work can be obtained at the same time, so that the position of the work can be corrected with high accuracy.

In a second aspect based on the first aspect, the detecting means detects the position of two of the three points from one of the two sides, and detects the position of the other of the three points. Is detected from another one of the two sides.

In the second invention, two points are detected from one side and another point is detected from the other side. Therefore, it is possible to reliably obtain the rotational displacement and the translation displacement of the work. it can.

[0011] In a third aspect based on the first aspect, the detecting means has first detecting means and second detecting means, and the first detecting means is one of the three points. Two points are detected, and the second detecting means detects another one of the three points.
It is characterized by detecting points.

As a result, similarly to the second aspect, the rotational displacement and the translation displacement of the work can be reliably obtained.

In a fourth aspect based on the third aspect, the first detecting means detects two of the three points from each of the two sides, and the second detecting means comprises: , One of the three points is detected from any one of the two sides.

Thus, as in the third aspect, the rotational displacement and the translation displacement of the work can be reliably obtained.

In a fifth aspect based on the first to fourth aspects, the work transfer device includes the detecting means or the first and second detection means on a main body of the work transfer device or on the hand. It is characterized by having.

Thus, it is possible to reliably and safely obtain the rotational shift amount and the parallel shift amount of the work on the transfer path of the work.

In a sixth aspect based on the first to fifth aspects, the detecting means detects the positions of the at least three points when the workpiece is being transported by the workpiece transport device. I do.

In the sixth aspect, since three points can be detected when the work is being conveyed, there is an effect that the position of the work can be corrected without affecting the cycle time. Further, even if the position of the work is displaced during the conveyance, the position can be corrected immediately, and the position can be corrected with high reliability.

According to a seventh aspect of the present invention, a work having at least two sides intersecting with each other on an extension thereof is placed on a hand of a work transfer device, and a positional shift of the work is detected. In a work transfer system that performs work transfer control, the work transfer system is provided on the work transfer device main body or the hand, and during transfer including immediately before the end of the transfer of the work, the work is placed on two sides of the work placed on the hand. Detecting means for detecting the positions of at least three points in the above, and obtaining the amount of rotational displacement and the amount of parallel displacement from the normal position of the workpiece based on the positions of at least three points detected by the detecting means. The transfer control of the work is performed.

In the seventh aspect, at least three positions on two sides of the workpiece are detected during the transportation including immediately before the completion of the transportation of the workpiece. Therefore, even if the positional deviation occurs during the transportation of the workpiece. Position correction can be appropriately performed. Further, the position of the work can be reliably corrected in the vicinity of the final transfer destination. Even when the position of the work in the vicinity of the transfer destination is insufficient, the work can be safely transferred without damaging the work. Can be achieved.

[0021]

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

FIG. 1 is a diagram showing a configuration of a work transfer system according to a first embodiment of the present invention. In FIG. 1, the work transfer system places a desired work 2a on a hand H of a work transfer robot R from a plurality of works 2 such as a glass substrate arranged in a cassette 1,
The hand H is moved to be stored in another cassette 3.

Under the control of the robot controller 9, the work transfer robot R rotates the shaft 6 by a drive motor (not shown) arranged in the robot main body 5, and moves the arm R 1 fixed vertically to the shaft 6. Rotate. The arm R1 connects the arm R2 by the shaft 7, and the arc R2 connects the hand H by the shaft 8. Axis 6,
The portions 7 and 8 are connected by a pulley and a belt, respectively, and are meshed at a predetermined ratio. For example,
The right rotation of the shaft 6 causes the shaft 7 to rotate to the left at twice the angle, and at the same time, the left rotation of the shaft 7 causes the shaft 8 to rotate to the right at a half angle relative to the rotation of the shaft 7. As a result, by rotating the shaft 6, the hand H can be moved back and forth without swinging. The shafts 6, 7, and 8 may be provided with independent motors to perform rotational drive control. On the other hand, the robot body 5 travels left and right on the traveling rails 4a and 4b. Therefore, a desired trajectory of the hand H between the cassette 1 and the cassette 3 can be drawn by appropriately combining the back and forth movement of the hand H and the left and right movement of the robot body 5. The robot body 5 has a turntable 5a, and the above-mentioned shaft 6 is mounted on the turntable 5a. Therefore, when the turntable 5a is rotated, it can be rotated while maintaining the shape from the arm R1 to the hand H. The shaft 6 on the robot body 5 can move up and down, and the hand H can be moved up and down by this up and down movement.

The work 2 is a glass substrate having the above-mentioned fixed shape, and is a rectangular thin flat plate. This work 2
Are placed at equal intervals in the vertical direction by frames provided on the inner side walls in the cassettes 1 and 3.

When transferring the work 2 in the cassette 1 to the cassette 3, the work transfer robot R first positions the robot body 5 in front of the cassette 1, rotates the shaft 6 counterclockwise to extend the hand H, and 1 Further, the hand H is advanced into the cassette 1 and the shaft 6 is moved upward to place a desired work 2 on the hand H. Thereafter, the hand 6 is contracted by rotating the shaft 6 clockwise, and is separated from the cassette 1. Thereafter, the robot body 5 is moved rightward according to the running rails 4a and 4b, and is moved to the front of the cassette 3. Thereafter, the hand H is extended by rotating the shaft 6 counterclockwise to enter the cassette 3. Thereafter, the shaft 6 is lowered to store the work 2 placed on the hand H in the cassette 3. It should be noted that the cycle time may be reduced by moving the robot body 5 right and left at the same time as the hand H is contracted or extended when the hand H is separated from the cassettes 1 and 3.

On the robot main body 5, three detection units 10 to 12 for detecting a displacement of the work 2a are provided.

Each of the detection units 10 to 12
The position of the side of the work is detected by sandwiching a from above and below. The detectors 10 and 11 detect the positions of two different points on the vertical side of the work 2a placed on the hand H, and the detector 12 detects the position of one point on the horizontal side. I do.

The configurations of the detecting units 10 to 12 are the same, and the detailed configuration of the detecting unit will be described with reference to the cross-sectional view taken along the line AA of one of the detecting units 10 shown in FIG.

In FIG. 2, the detecting section 10 includes a light emitting section 10a.
And a linear sensor 10b functioning as a light receiving unit,
These are held by a bracket 14 fixed to the robot body 5. A predetermined laser beam is emitted from the light emitting section 10a toward the linear sensor 10b, and the linear sensor 10b receives and detects this laser beam. Light emitting unit 1
The workpiece 0a and the linear sensor 10b are arranged so that the workpiece placed on the hand H is always interposed between them even if the workpiece 2a is slightly displaced. When the laser light from the light emitting unit 10a corresponding to the position of the linear sensor 10b is received through the work 2a, the laser light is compared with the case where the laser light is directly received from the light emitting unit 10a due to the attenuation or scattering characteristics of the work. As a result, the received light intensity decreases. By utilizing this characteristic, the position P1 of the vertical side of the work 2a can be detected.

Similarly, the detecting section 11 detects the position P2 of the vertical side of the work 2a, and the detecting section 12 detects the position P3 of the horizontal side of the work 2a. And these positions P
The values of 1 to P3 are sent to the robot controller 9 and the following arithmetic processing is performed to detect the displacement of the work 2a.

FIG. 3 is an explanatory diagram for explaining the processing for calculating the positional deviation of the work when the angle between the two sides is a right angle.
In FIG. 3, the position of the work 2b indicated by a broken line is a regular position without a position shift, and the position of the work 2a is a position where a position shift occurs. Side L1 and side M1 of work 2b
Is the origin as a reference, the side L1 is the X axis, the side M1
Is set as a reference plane using a two-dimensional plane as the Y axis. In addition, as described above, the detection units 10 and 11 are arranged so as to overlap on the Y axis in parallel with the X axis, and
Are arranged so as to overlap on the X axis in parallel with the Y axis. Here, the respective detection outputs of the detection units 10 to 12 when there is no displacement are outputs S1 to S3, respectively. In addition, the respective detection outputs of the detection units 10 to 12 when the position shift occurs are the outputs P1 to P3, respectively. Further, the distances in the Y direction from the origins of the detectors 10 and 11 arranged on the Y axis are Y1 and Y2, respectively, and the distances in the X direction from the origin of the detectors 12 arranged on the X axis are X1. .

Here, the rotation amount θ of the work 2a having the position shift and the movement amount (X0,
Y0) will be described. First, tan θ
= ((P2-S2)-(P1-S1)) / (Y1-Y2), and the rotation amount θ is Becomes On the other hand, the equation of the straight line of the side L2 passing through the vertex P is y-Y0 = tanθ. (X-X0). Since this straight line passes through the point (X1, P3-S3), (P3-S3) -Y0 = Tan θ · (X1-X0) (1) The equation of the straight line of the side M2 orthogonal to the straight line of the side L2 is as follows: when θ = 0, (y−Y0) = (− 1 / tan θ) · (x−X0), and this straight line is a point (P2-S2 , Y2), then (Y2-Y0) = (− 1 / tan θ) · (P2-S2-X0) (2)

By solving the simultaneous linear equation of the equations (1) and (2), X0 = sin θ · cos θ · (−P3 + S3 + Y2 + tan θ · X1 + (P2-S2) / t
anθ) Y0 ＝ Y2 ＋ cosθ ・ (cosθ ・ (P3-S3-Y2) + sinθ ・ (-X1 + P2-
S2)). On the other hand, when θ = 0, X0 = (P2-S2) Y0 = (P3-S3).

Thus, the rotation amount θ and the movement amount (X0, Y
0) is required. The rotation amount θ and the movement amount (X0, Y0) are obtained by the robot controller 9, and the robot controller 9 performs compensation control for moving the hand H based on the positional deviation amount, and the work 2a Position.

In this case, since the positions of the three points on the work 2a are simultaneously detected by the detection units 10 to 12, it is possible to detect an accurate positional deviation.

Further, since it is detected in the middle of the transport trajectory of the work 2a, the cycle time is not affected.

In addition, it is possible to continuously detect a positional deviation which is likely to occur during the transfer of the work 2a, for example, when the robot body 5 moves at high speed on the traveling rails 4a and 4b. That is, when the detection units 10 to 12 are provided on the hand H, the traveling rail 4 is used until immediately before the workpiece 2a is stored, and when the detection units 10 to 12 are provided in the robot body 5.
a and 4b can be detected during traveling. As a result, highly reliable position compensation becomes possible, and the work 2
a can be eliminated.

In the work transfer system shown in FIG. 1, two detectors 10 and 11 are provided on the vertical side of the work 2a to detect two points P1 and P2 on the vertical side, and to detect one point on the horizontal side. Although one detecting section 12 is provided to detect one point P3 on the horizontal side, one detecting section is provided on the vertical side, two detecting sections are provided on the horizontal side, and the vertical side is provided. The above-described positional shift may be detected from two points, one point and a horizontal side.

Further, two detectors 2 as shown in FIG.
0, 21 may be used to detect the displacement of the work 2a. In this case, the point P11 on the vertical side is detected by the detection unit 20, and the point P12 on the vertical side and the point P13 on the horizontal side are detected by the detection unit 21. Even with such a configuration, since the three points P11 to P13 are detected, the above-described calculation can be performed.

The three points P11 to P13 or the three points P1
P3 are points on the side of the work 2a, and 2 out of the 3 points
A point is detected from a vertical side, and one of three points is detected from a horizontal side. The two sides on which the three points are detected need to be sides that can intersect on an extension of the two sides. However, they need not intersect at right angles. Also, these two sides are the work 2a
However, the present invention is not limited to this, and it is sufficient if there are two detectable sides on the work.

In the above-described work transfer system,
Although three points on two sides of the work 2a are directly detected, an image of the work 2a is acquired on a predetermined trajectory, and image processing of the acquired image is performed to extract the two sides. Alternatively, the amount of displacement from two sides when there is no displacement may be obtained.

Further, in the above-described work transfer system, all of the detection units are provided on the robot main body 5 of the work transfer robot R. However, the present invention is not limited to this.
May be provided on the hand H within a range that does not hinder the taking in and out of the cassette 1.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a work transfer system according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of the detection unit 10.

FIG. 3 is an explanatory diagram illustrating a calculation process of a positional shift of a workpiece when an angle between two sides is a right angle;

FIG. 4 is a diagram showing a configuration for obtaining three points by two detection units.

[Explanation of symbols]

1, 3 ... cassette 2, 2a ... work 4a, 4b ... travel rail 5 ... robot body 5a ... turntable 6-8 ... axis 9 ... robot controller 10-12 ... detection unit 10a ... light emitting unit 10b ... linear sensor 14 ... bracket R: Work transfer robot R1, R
2: Arm H: Hand

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3F059 AA01 AA14 BA04 BB05 DA02 DD12 DE01 FB12 FB16 5F031 AA10 BB05 CC13 GG02 GG06 GG12 GG20

Claims (7)

[Claims] 1. A work having at least two sides intersecting with each other on an extension thereof is placed on a hand of a work transfer device, a position shift of the work is detected, and transfer control of the work is performed based on the detection result. A detecting means for detecting positions of at least three points on two sides of the work placed on the hand, based on the positions of at least three points detected by the detecting means. A transfer control of the work by calculating a rotational shift amount and a parallel shift amount of the work from a normal position. 2. The detecting means detects a position of two of the three points from one of the two sides, and detects a position of another one of the three points of the two sides. 2. The work transfer system according to claim 1, wherein the detection is performed from another one of the sides. 3. The apparatus according to claim 2, wherein said detecting means includes a first detecting means and a second detecting means.
Wherein the first detecting means detects two of the three points, and the second detecting means detects another one of the three points. The work transfer system according to claim 1, wherein: 4. The first detecting means detects two of the three points from each of the two sides, and the second detecting means detects another one of the three points. The workpiece transfer system according to claim 3, wherein a point is detected from any one of the two sides. 5. The work transfer device according to claim 1, wherein said work transfer device includes said detection means or said first and second detection means on a main body of said work transfer device or on said hand. The work transfer system according to any one of the above. 6. The apparatus according to claim 1, wherein said detecting means detects the positions of said at least three points when said workpiece is being transported by said workpiece transport device.
The work transfer system according to any one of the above. 7. A work having at least two sides intersecting on an extension thereof is placed on a hand of a work transfer device, a position shift of the work is detected, and transfer control of the work is performed based on the detection result. In the work transfer system, at least three points on two sides of the work placed on the hand are provided on the work transfer device main body or the hand during transfer including immediately before the transfer of the work is completed. Detecting the position of the work, and calculating the rotational displacement and the parallel displacement from the regular position of the work based on the positions of at least three points detected by the detecting means, and transporting the work. A work transfer system characterized by performing control.