JPH1148175A - Rotary shaft center positioning position offset correction method and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize high accurate positioning reducing a three-dimensional positioning error generated according to rotation of a rotary hand in an industrial robot. SOLUTION: This device is controlled by a computer 33, to be constituted by having a part clamping rotary hand 10 synthetically moved through an X/Y-axis mechanism part α, β by rotating an X/Y-axis motor 2, 5 for positioning on a two-dimensional virtual coordinate. In this case, the device comprises a photoelectric switch 15, 16 through mounted in two or more standard positions of a board 13 assigning a plurality of positioning target positions to be set on a three-dimensional virtual coordinate also to be connected to the computer 33 via in the halfway successively amplifiers 30, 31 and an interface 32, part 12 clamped in the part clamping rotary hand 10 to be detected by the photoelectric switch 15, 16 for two-dimensional in-plane orthogonal movement in parallel to the board 13 in the X/Y-axis mechanism part α, β and a rotary mechanism rotating the part clamping rotary hand 10 clamping the part 12 around a shaft for detecting a shaft center position of the part 12 by the photoelectric switch 15, 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of correcting a rotational axis center position offset in a high-precision positioning system using a robot, and an apparatus directly used for implementing the method. Here, the position offset means a difference between a target position and an actually positioned position, that is, a low frequency component generated due to a temperature variation, an origin error, and the like due to a position error.

[0002]

2. Description of the Related Art A circular pin-shaped part is used as a part.
Positioning device T for rotationally inserting a part into a rotary insertion hole
9 is a plan view of the board, FIG. 10B is a cross-sectional view taken along line Xb-Xb in FIG. 10A, and an enlarged view of the vicinity of the tip of the rotary hand for gripping parts. Is shown. Here, 1 is an X-axis moving stage, 2 is an X-axis driving motor, 3 is an X-axis driving ball screw, 4 is a Y-axis moving stage, 5 is a Y-axis driving motor, and 6 is a Y-axis driving Ball screw, 7 is a Z-axis moving stage, 8 is a Z-axis driving motor,
Reference numeral 9 denotes a Z-axis driving ball screw.

[0003] Reference numeral 10 denotes a rotary hand for gripping a component, 11 denotes a motor for opening and closing the tip of the rotary hand 10 for gripping a component, 12 denotes a component, 13 denotes a board as an article to be mounted to which a plurality of positioning target positions are designated, 14 Is a rotary insertion hole as a rotary assembling hole into which the component 12 is inserted, and 15 and 16 are pseudo-partial photoelectric switches having a cylindrical pin shape or the like in appearance as a sensor that is turned on by the intensity of reflected light from an object. is there.

Reference numeral 20 denotes a driver for driving the Y-axis drive motor 5, 21 denotes a driver for driving the X-axis drive motor 2, 22a and 22b denote controllers for driving the motors 2, 5, 30, 31 is an amplifier for the photoelectric switch, 32 is an interface circuit for taking in the signal of the photoelectric switch into the computer, and 33 is a computer (CPU) for controlling the movement of the motor.

Here, when the object moves to a position where the light projected from the photoelectric switches 15 and 16 is reflected by the object, the reflected light enters the photoelectric switches 15 and 16 and the photoelectric switches 15 and 16 are moved. It turns on. Also,
Since it is necessary to rotate the hand 10 in accordance with removal and insertion of the component 12, the component gripping rotary hand 10 is configured to be able to rotate about the axis of the rotary hand 10.

As shown in FIGS. 9 and 10 (a) and 10 (b), a photoelectric switch is inserted into an appropriate portion of the board 13 (in the illustrated example, a rotary insertion hole 14 for inserting a component 12 at a diagonal of the board 13). 15 and 16 are arranged so as to face the rotating hand 10 for gripping parts. It is assumed that the rotary insertion hole 14 of the component 12 is regularly opened in the board 13.
Also, pulse motors are used as the motors 2, 5, 8, and 11. Part 1 with complete positioning
If the center of 2 and the center of the rotary insertion hole 14 coincide, insertion is possible without any problem. The rotation of the component 12 into the desired rotation insertion hole 14 is performed as follows.

First, the positions of the motors 2 and 5 for each of the X and Y axes are positioned at the origin. That is, the controller 22a, 22b of the motors 2, 5 sends the movement pulse signal P to the X-axis driving motor 2 and the Y-axis driving motor 5 in response to a command from the computer 33.
Release a and Pb. The drivers 20 and 21 supply current to a plurality of windings of the motors 2 and 5 according to the movement pulse signals Pa and Pb, and rotate by the number of movement pulses.

The rotation of the X-axis drive motor 2 is transmitted to the X-axis drive ball screw 3, and the X-axis mechanism α causes the Y-axis mechanism β, the Z-axis mechanism γ, and the hand mechanism δ for gripping parts and tools.
Moves. Similarly, the motors 2, 5, 8 of each axis are rotated and moved in one direction, and the X-axis, Y-axis, Z-axis stages 1,
A three-dimensional virtual coordinate origin is detected by a microswitch, a photosensor, or the like (not shown) fixed to 4, 7. As a result, the motors 2, 5, and 8 are stopped, and the position coordinates for disturbance that are software-managed on the computer 33 are reset.

Next, the part 12 is moved to a place where the parts 12 are aligned (not shown), and the part 12 is gripped by the rotating part gripping hand 10. Since the position of the rotary insertion hole 14 is given in advance by the distance from the origin of each axis (specifically, the number of drive pulses for a pulse motor, the number of movement pulses detected by an encoder for a DC motor, etc.) By referencing, the rotating hand 10 for gripping the component is moved to the center of the position of the desired rotary insertion hole 14.

The component 12 is gripped by the component gripping rotary hand 10, and the front surface of the photoelectric switch 15 is scanned in parallel with the board 13 by the component gripping rotary hand 10. Photoelectric switch 15
In order to obtain the center position of the hole in which is disposed, the component gripping rotary hand 10 is scanned with the photoelectric switch 15 in two directions orthogonal to the horizontal X-axis direction and the Y-axis direction in a vertical two-dimensional plane.

By scanning the component gripping rotary hand 10, a position where the photoelectric switch 15 changes from off to on or a position where the photoelectric switch 15 changes from on to off is detected. Area that is turned on). From the center position of this ON region, the center position of the through-hole in which the photoelectric switch 15 is arranged is determined. Next, the offset amount between the center position of the through-hole where the photoelectric switch 15 is provided in advance and the center position of the through-hole obtained just now is calculated.

Next, the same operation as above is performed on the photoelectric switch 16 to obtain an offset amount between the center position of the through hole where the photoelectric switch 16 is arranged and the center position of the through hole just obtained. The correction position of an arbitrary point in the board 13 is obtained from the two offset amounts by the interpolation method. In addition,
In this case, it is assumed that the board 13 is uniformly deformed. FIGS. 10A and 10B show a state near the component gripping rotary hand 10 immediately before the component 12 is rotationally inserted.
FIG. 3B is a cross-sectional view of the board 13 taken along line Xb-Xb in FIG.

[0013]

In order to measure the offset amount at a rotation angle of the rotary hand 10 of 0 °, when the component gripping rotary hand 10 is rotated by 180 ° and the component 12 is gripped or rotationally inserted, the component gripping is performed. Due to the inclination of the rotary hand 10 for use, the displacement of the rotation axis, etc., there may be cases where the component 12 cannot be gripped or cannot be rotated and inserted into the rotary insertion hole 14. That is, since the position offset correction is limited to only the rotational position of one of the rotating hands 10 for gripping one component, accurate positioning cannot be performed at the opposite rotational position.

Here, the main objects to be solved by the present invention are as follows. That is, a first object of the present invention is to provide a method and an apparatus for correcting a rotational axis center position offset for realizing high-precision positioning for reducing a three-dimensional positioning error caused by rotation of a rotary hand. Is what you do.

A second object of the present invention is to provide a method and an apparatus for correcting a rotational axis center position offset which enables position offset correction irrespective of the rotational position of the rotary hand and always enable high-accuracy positioning control. Is what you do.

A third feature of the present invention is to provide a method and an apparatus for correcting a rotational axis centering position offset for obtaining a position offset amount at a rotational position of 0 ° and 180 ° of the rotating hand.

Another object of the present invention is to provide a specification, drawings,
In particular, it will be obvious from the description of each claim in the claims.

[0018]

According to the present invention, in order to solve the above-mentioned problems, an offset amount at the time of 180-degree rotation is measured in order to compensate for an offset error caused by the rotation of the rotary hand. In this case, one corner (for example, photoelectric switch 15)
Only), the position of the rotary insertion hole 14 can be obtained using the 0 degree measurement data.

If the rotary hand 10 for gripping parts is moved based on the offset amount thus obtained, the rotary hand 1
Regardless of the 0 rotation position, the board 13 can be accurately positioned at the center of the rotation insertion hole 14 even with respect to the board 13 which has been expanded and contracted due to aging. At this time, the rotary insertion hole 1 of the board 13 is
The change in the four positions is treated as if the expansion and contraction of the board 13 has occurred uniformly.

More specifically, in order to solve the problem, the present invention achieves the above object by adopting a novel characteristic configuration method and means ranging from a superordinate concept to a subordinate concept listed below. To achieve.

A first feature of the method of the present invention is that a corresponding part / tool is gripped with respect to a plurality of rotation axis centering target positions set in advance on an assembly / work set on three-dimensional virtual coordinates. In carrying out offset correction with each planned rotation axis center position of the rotating hand means for gripping the parts to be conveyed and rotationally assembled / rotated, centering on the multiple reference positions of the assembled / workpiece Each sensor provided with
The non-contact scanning is performed with the component / tool gripped by the rotating hand means for gripping the tool facing, the on / off signal of the sensor is detected, and the two-dimensional axis center position of the sensor is determined from the center of the detection inner area determined and detected. The three-dimensional axis of the sensor and the part / tool are rotated by rotating the part / tool gripping rotary hand means for holding the part / tool with the axis center facing the axis position. The position offset amount, such as the inclination of the three-dimensional axis center and the deviation of the rotation axis, is calculated and calculated.
The present invention resides in the configuration of a method of correcting a rotational axis center position offset by calculating a correction amount using the axis position of the sensor as an origin of offset calculation with respect to each of the rotary axis center positioning targets.

According to a second aspect of the method of the present invention, there is provided a method of correcting a rotational axis centering position offset, wherein the sensor according to the first aspect of the present invention sticks out and protrudes from a work to be assembled / worked.

According to a third feature of the method of the present invention, the method according to the first or second feature of the present invention is such that the sensor is a non-contact switch such as a photoelectric switch or a proximity switch. Configuration adoption.

A fourth feature of the method of the present invention resides in that the sensor according to the first, second or third feature of the method of the present invention is formed by rotating the sensor by forming a part / tool pseudo shape such as a cylindrical pin in appearance. The present invention resides in adopting the configuration of the method of correcting the offset of the axial center positioning position.

According to a fifth feature of the method of the present invention, the non-contact scanning of the part / tool in the first, second, third or fourth feature of the method of the present invention is performed in such a manner that the orthogonality to the sensor end face in a two-dimensional plane is obtained. The present invention resides in adopting a configuration of a method of correcting a rotational axis center position offset which is a directional scan.

A sixth feature of the method of the present invention is that the on / off signal of the sensor according to the first, second, third, fourth or fifth feature of the method of the present invention is obtained by detecting an edge of a part / tool end face. In this embodiment, an ON signal is detected when the signal passes from the outside to the inside, and an OFF signal is detected when the signal passes from the inside to the outside.

A seventh feature of the method of the present invention is that the measurement calculation of the axial position of the sensor in the first, second, third, fourth, fifth or sixth feature of the method of the present invention is performed by a computer. In this case, the configuration of the method for correcting the offset of the rotational axis center position, which is an arithmetic processing by the above, is adopted.

An eighth feature of the method of the present invention is that the article to be assembled according to the first, second, third, fourth, fifth, sixth or seventh feature of the method of the present invention is such that the rotating shaft is An object of the present invention is to adopt a configuration of a method of correcting a rotational axis center position offset, which is a board in which rotary insertion holes, which are rotary assembly holes, are arranged regularly or irregularly at a center position.

A ninth feature of the method of the present invention resides in that, in the eighth feature of the method of the present invention, the part is a pin that is rotatably inserted into a rotary insertion hole which is provided in a part to be assembled. It is in the configuration adoption of the offset correction method for positioning.

A tenth feature of the method of the present invention resides in that the sensor according to the eighth or ninth feature of the method of the present invention is arranged such that the sensor has two corner holes arranged at a plurality of corners of a group of rotary assembling holes of an article to be assembled. The present invention resides in adopting a configuration of a method of correcting an offset of a rotation axis center position, which is formed by projecting into one or more penetration holes.

An eleventh feature of the method of the present invention resides in that the sensor according to the eighth or ninth feature of the method of the present invention is arranged such that the sensor has one of the corner holes arranged at a plurality of corners of the group of rotary assembling holes of the article to be assembled. One or more through-holes and a rotation axis centering position offset correction method configured to penetrate and project through the through-hole of the center hole disposed at the center position of the rotary assembly hole group.

According to a twelfth aspect of the method of the present invention, the sensor according to the tenth or eleventh aspect of the present invention is characterized in that the sensor is mounted so that the center of the hole is aligned with the hole axis of the through hole by the alignment holding means. The present invention resides in adopting a configuration of a method of correcting a position offset of a rotating shaft center position that protrudes.

A thirteenth feature of the method of the present invention is that the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, and eleventh aspects of the method of the present invention are described. Or, the rotation about the axis of the rotating hand means for gripping parts / tools in the twelfth aspect is 180 degrees.
The present invention resides in adopting a configuration of a method of correcting a rotational axis center position offset which is a rotation by °.

A fourteenth feature of the method of the present invention is that the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, and eleventh of the method of the present invention are described. The twelfth or thirteenth feature of the present invention resides in the adoption of a configuration of a rotation axis centering position offset correction method in which the axis shift position offset amount in the twelfth or thirteenth feature is a position offset amount before and after the rotation of the rotary hand means for gripping parts and tools by 180 °. .

The first feature of the present invention is that an X-axis and Y-axis motor for positioning on two-dimensional virtual coordinates, an X-axis and a Y-axis driver for driving the X-axis and Y-axis motors, An X-axis and Y-axis controller for generating the motor drive signals; a computer for centrally controlling the driving of the X-axis and Y-axis motors; and an X-axis and Y-axis mechanism by rotating the X-axis and Y-axis motors. In a positioning device having a position offset correction function, which is composed of a part / tool gripping hand mechanism unit that is synthesized and moved via a unit, a set of a plurality of positioning target positions specified in advance on three-dimensional virtual coordinates. A sensor which is provided in alignment with two or more standard positions of attachments and works and which is sequentially connected to a computer via an amplifier and an interface in the middle, and the X-axis and Y-axis gripped by the hand mechanism for gripping parts and tools. A part / tool whose movement is detected by the sensor in the orthogonal direction in a two-dimensional plane parallel to the work to be assembled / worked by the mechanism, and a hand mechanism for gripping the part / tool holding the part / tool. Rotate the part and
And a rotation mechanism for detecting the axis position of the tool by the sensor.

A second feature of the device of the present invention is that the sensor in the first feature of the device of the present invention is provided with an alignment mounting and holding member such that the sensor coincides with the axial center of the through hole formed in the standard position. The present invention resides in the configuration and adoption of a rotational axis centering position offset correcting device formed by sticking out and projecting with the shaft center aligned.

A third feature of the device of the present invention is that the sensor according to the first or second feature of the device of the present invention is characterized in that the sensor is a contactless switch such as a photoelectric switch or a proximity switch. In the configuration adoption.

A fourth feature of the device of the present invention is that the photoelectric switch according to the third feature of the device of the present invention is such that the optical fiber for emission and the optical fiber for detecting reflected light are housed in a single cylindrical case. The present invention resides in adopting the configuration of a rotation axis center position offset correction device which is a fiber type photoelectric switch.

A fifth feature of the device of the present invention is that the photoelectric switch in the third feature of the device of the present invention has a large number of thin radiating optical fibers arranged around a centrally located reflected light detecting optical fiber. Rotational axis positioning position offset correction device that is a reflection type photoelectric switch.

A sixth feature of the present invention is that the motor according to the first, second, third, fourth or fifth feature of the present invention is a pulse motor or an input command pulse issued from a motor driver. The present invention resides in the configuration adoption of a rotary shaft center positioning position offset correction device that is a DC or AC motor with an encoder that rotates with.

A seventh feature of the device of the present invention resides in that the rotation mechanism in the first, second, third, fourth, fifth or sixth feature of the device of the present invention is characterized in that the rotation mechanism stops rotation by 0 ° to 180 °. The present invention resides in adoption of a configuration of a rotation axis centering position offset correcting device that can be freely adjusted.

An eighth feature of the device of the present invention is that the rotating mechanism according to the first, second, third, fourth, fifth, sixth or seventh feature of the device of the present invention operates the rotating mechanism. A rotation mechanism driver to be driven, a rotation mechanism controller for controlling the rotation mechanism driver, and a computer for commanding the rotation mechanism controller; and a rotation axis center positioning position offset connected to a command control drive system. The present invention lies in the configuration of the correction device.

A ninth feature of the device of the present invention resides in that the rotating mechanism in the first, second, third, fourth, fifth, sixth, seventh or eighth feature of the device of the present invention is characterized in that: An object of the present invention is to adopt a configuration of a rotation axis center position offset correction device which enables the entire opening / closing motor of a tool tip hand opening / closing unit to be rotatable integrally.

A tenth feature of the device of the present invention resides in that the rotating mechanism in the ninth feature of the device of the present invention is arranged such that a component is mounted on a slide table on which a component / tool gripping hand mechanism is mounted via an omnidirectional tilt adjustment mechanism. The configuration of a rotary axis center position offset correction device which is mounted integrally with the tool gripping hand opening / closing motor so as to be capable of tilt adjustment is employed.

[0045]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings with respect to an example of an apparatus and an example of a method thereof. In this embodiment, the assembled product such as the board 13 and the component 12 will be described. However, the work can be replaced with a work and a tool can be used.
As an electric tool electrically connected to the workpiece 33, the present invention can be applied to positioning of a machining axis of a tool with respect to a workpiece.

(Example of Apparatus) FIG. 1 is a system configuration diagram of a positioning apparatus T 'having a position offset correction function in which an example of the apparatus U is integrated. In the figure, reference numeral 34 denotes a rotating mechanism for integrally rotating the rotating hand 10 and the motor 11 of the rotating hand mechanism δ for component gripping around an axis; 35, a rotating mechanism driver;
Is a rotary mechanism controller, and 37 is an omnidirectional tilt adjustment mechanism of the axis of the rotary hand 10.

FIGS. 9 and 10 (a) show the conventional example.
The same components in (b) are given the same reference numerals to avoid duplication of description. In this device example U, the photoelectric switches 15 and 16 and the amplifier 3
0, 31, an interface 32, a computer 33, a rotating mechanism 34, a rotating mechanism driver 35, a rotating mechanism controller 36, and an omnidirectional tilt adjusting mechanism 37.

The rotation mechanism 34 includes a rotation mechanism driver 35 for operating and driving the rotation mechanism 34 and a rotation mechanism driver 3
5 is connected to a command control drive system including a rotation mechanism control 36 for controlling the rotation mechanism 5 and a computer 33 for controlling and controlling the rotation mechanism controller 36. And an omnidirectional tilt adjustment mechanism 37 on the slide table δ1 of the rotary hand mechanism δ for gripping parts and tools.
It is mounted integrally with the rotary hand 10 for opening and closing the tip of the rotating hand 10 for gripping parts and tools via the through hole so as to be capable of fine adjustment.

(Example of Method) An example of the method according to the present embodiment applied to the example of the present apparatus will be described with reference to the drawings. (1) Preliminary work of two-dimensional offset correction FIG. 2 is a diagram illustrating a preliminary work of two-dimensional offset correction of the present method example, (a) is a plan view of the board 13, and (b) is the same.
FIG. 3A is a cross-sectional view taken along line IIb-IIb and an enlarged view of the vicinity of the tip of the component gripping hand 10, FIG. 3 is a diagram illustrating the measurement principle of the ON region Ron of the photoelectric switch, FIG. FIG.
FIG. 6 is an explanatory diagram of the shift amount of the same / adjacent interval, and FIG. 6 is a flowchart for obtaining the offset amount of the center positions of the through holes 14a and 14b of the photoelectric switches 15 and 16.

As shown in FIGS. 2 (a), 2 (b) and 4, an appropriate representative position on the surface of the board 13 (here, a diagonally longest diagonal of the rotary insertion holes 14 penetrating through the board 13). The photoelectric switches 15, 15 are respectively provided in the through holes 14 a, 14 b).
16 is the finger end 10a of the rotary hand 10 for gripping parts.
Alignment mounting holding member 1 such as upper and lower nuts to face
At 5a, 15b, 16a, 16b, penetration holes 14a, 14
The center of the hole is aligned with the center of the hole b. Next, the component 12 is gripped by the component gripping rotary hand 10.

For the purpose of improving the detection accuracy, it is desirable to use a standard component having relatively high dimensional accuracy as the component 12 to be gripped. However, it is naturally applicable to a general-purpose rotary insertion component. .

First, the component gripping rotary hand 10 gripping the component 12 is positioned at the X-axis scanning start point Pxo1. The X-axis scanning start point Pxo1 also depends on the deformation amount of the board 13, but here, as an example, the penetration holes 14a, 14
The position is away from the center of the through holes 14a and 14b in which the photoelectric switches 15 and 16 are inserted by the diameter of b.

The X-axis driving pulse motor 2 is rotationally driven from the CPU 33 via the controller 22b and the driver 21 in order to start scanning in the X-axis parallel direction. When reaching the point Pxa1 by scanning as shown in FIG.
The switches 5 and 16 make a transition from the OFF state to the ON state, and further continue scanning, and when they reach the point Pxb1, the photoelectric switches 15 and 16 again make a transition from the ON state to the OFF state.

As a result of one scan through point Pxo1 → point Pxa1 → point Pxb1, the arithmetic mean value of the number of moving pulses Pb ′ when passing through point Pxa1 and the moving pulse Pb ″ when passing through point Pxb1 (( Pb ′ + Pb ″) / 2) is the ON region Ron
X-coordinate of the center point of. Subsequently, after the component gripping hand 10 is slightly moved in the Y-axis direction, scanning in the X-axis direction via the point Pxo2 → point Pxa2 → point Pxb2 is started again as before, and the number of movement pulses Pb ′ and Pb "
Ask for.

Next, the rotary hand 10 for gripping the component is positioned at the Y-axis scanning start point Pyo1 on the X-axis, and similarly to the scanning in the X-axis parallel direction, the Y-axis parallel movement via the point Pyo1 → point Pya1 → point Pyb1 is performed. Scan in the direction. Further point Pyo2 → point P
The scanning in the direction parallel to the Y-axis via the point ya2 → the point Pyb2 is performed again in the same procedure.

The center point Pc (Xc, Yc) of the ON region Ron
Is obtained by taking the arithmetic mean of each coordinate component transferred and stored in the CPU 33, so that Xc = (Pb1 ') when scanning is performed twice each in the X-axis and Y-axis parallel directions as in the present method example. + Pb1 ″ + Pb2 ′ + Pb2 ″) / 4 Yc = (Pa1 ′ + Pa1 ″ + Pa2 ′ + Pa2 ″) / 4 (1) As a matter of course, the error in the arithmetic averaging decreases as the number of measurements increases, so that the detection accuracy is improved.

In the case where the light emitting portions and the reflected light detecting portions of the photoelectric switches 15 and 16 are not on the same optical axis and the emission direction is not axially symmetric, or the light emission pattern from the light emitting portions is not isotropic. In such a case, the penetration hole 1 in which the photoelectric switches 15 and 16 of the board 13 and the center point Pc of the ON region Ron are disposed.
There is a shift between the center point Ph of 4a and 14b due to the shift in the same plane.

In such a case, paying attention to the fact that the shift distance is constant, the shift distance is measured in advance by a microscope or the like, and the position of the center point Pc of the ON region Ron is determined by the shift amount. By moving the photoelectric switches 15 and 16 in advance, the center positions of the through holes 14a and 14b in which the photoelectric switches 15 and 16 are inserted can be accurately determined.

(Measurement Results) FIG. 4 is a measurement diagram of the ON region Ron of the photoelectric switch 15. In preparing the measurement diagram, the three-axis moving stage 1 in which the components 12 are integrally combined
The component gripping rotary hand 10 mounted on the components 4 and 7 was fixed by gripping, and was arranged in front of the photoelectric switch 15.
The on-region Ron and the off-region Roff of the photoelectric switch 15 are moved while moving the part 12 by a small amount by a micrometer (not shown) attached to the three-axis moving stages 1, 4, and 7.
Is measured. The horizontal axis and the vertical axis in the figure indicate the X coordinate and the Y coordinate of the position of the component 12, respectively.

While observing with a microscope, the photoelectric switch 15,
The three-axis fine movement stages 1, 4, and 7 are finely adjusted so that the centers of the through holes 14a and 14b through which the holes 16 are fitted and the centers of the photoelectric switches 15 and 16, respectively. , 7 are the centers of the penetration holes 14a, 14b through which the photoelectric switches 15, 16 penetrate. This center is XY
The base point of the coordinate system. As the component 12, a ferrule for an optical fiber was employed.

The first measurement value when the distance l between the component 12 and the photoelectric switches 15 and 16 is l = 0.5 mm is shown by a circle in the figure.
The second measurement value is indicated by a mark x in the figure. The thick solid line in the figure is a line connecting the measured values and forms a circle. The mark ◎ in the figure, which is the center point of the circle, is the center point Pc of the ON region Ron, and the mark ● in the figure is the penetration holes 14a, 1 through which the photoelectric switch 15 is penetrated.
This is the center point Ph of 4b. Center point Pc of ON region Ron
(Indicated by ◎ in the figure) is 10 μm in the X-axis direction and 30 μm in the Y-axis direction from the center point Ph (indicated by ● in the figure) of the penetration holes 14a and 14b.
Deviation has occurred.

Due to the structure of the photoelectric switches 15 and 16, the center point Pc of the ON region Ron (marked with ◎ in the figure) does not coincide with the center point Ph of the penetration hole 14a (marked with ● in the figure). However, since this distance difference is constant if the types of the photoelectric switches 15 and 16 employed are the same, the distance difference is measured and subtracted in advance in this way, so that the photoelectric switch 1 can be obtained.
The actual center positions of the penetration holes 14a and 14b into which the holes 5 and 16 are inserted are obtained. In the measured values shown in FIG. 5, the distance difference is of the order of several tens of μm, so that the penetration hole 14 has an accuracy of several tens of μm.
An accurate position of the center point Ph (indicated by ● in the figure) of a, 14b is obtained.

FIG. 5 shows a virtual coordinate axis for explaining a method of correcting the positions of the through holes 14a and 14b and a relative arrangement of the board 13 set thereon. Here, it is assumed that the rotary insertion holes 14 are arranged in a plane lattice shape with a constant interval between adjacent ones. The board 13 expands and contracts slightly in the plane direction due to temperature changes and other external factors, and the through holes 14a and 14b through which the photoelectric switches 15 and 16 are inserted as shown in FIG.
Is the position P1 (X1, Y) before the offset correction.
1), P2 (X2, Y2) to Pn1 (Xn1, Yn1), Pn1
It is assumed that they have moved to n2 (Xn2, Yn2).

Similarly, before the offset correction, the mutually adjacent spacing of the rotary insertion holes 14 in the X-axis and Y-axis directions is (dx,
It is assumed that (dy) has changed to (dnx, dny).
Here, the arrow in the figure indicates a transition from before correction to after correction. The board 13 is provided with a number of nx rotary insertion holes 14 in the X-axis direction and ny in the Y-axis direction. For reference, the total number of the rotary insertion holes 14 is nx since the photoelectric switches 15 and 16 are mounted at two locations.
× ny-2.

The mutual mutual spacing (dnx, dny) in the X-axis and Y-axis directions of the rotational insertion hole 14 after the shift is dnx = (Xn2-Xn1) / (nx-1) dny = (Yn2-Yn1) / (Ny-1).

Similarly, the rotational insertion hole Pnm (Xn, Y
m) becomes Xn = Xn1 + (n-1) dnx ... (2) Ym = Yn1 + (ny-m) dny ... (3) Here, the rotation insertion hole closest to the origin in the drawing is P11, and an arbitrary rotation insertion hole is Pnm.

The calculation result of the position of the rotary insertion hole 14 after the shift calculated in the CPU 33 by the formulas (2) and (3) is sent to the controllers 22a and 22b, and the respective controllers 22a and 22b output the driving pulse signal. Pa and Pb are sent to the drivers 20 and 21. The drivers 20 and 21 drive the driving operation signal S corresponding to the driving pulse signals Pa and Pb.
a and Sb are rotationally driven by applying a number of drive pulse voltages corresponding to the shift distance to the respective pulse motors 2 and 5, and moving the component gripping rotary hand 10 to the position of the rotary insertion hole 14 after the shift. I do.

Here, the case where the board 13 expands and contracts has been described as an example. However, even when the origin position of the reference coordinate system is deviated from an accurate position due to an external factor such as a temperature change, the same as in the present embodiment. The offset correction is possible from the equations (2) and (3). The above details are described in JP-A-7-234.
See, for example, U.S. Pat.

FIG. 6 shows a flowchart for software detection. In the figure, the center point of the two photoelectric switches 15 and 16 is obtained. A position of a rotating hand (hereinafter, a hand in the figure) 10 is determined in advance with respect to a storage position of the component 12 (ST1). First, the rotary hand 10 holding the component 12 (ST2) is positioned at the X-axis scanning start point A (ST5).
The part 12 is pulled out with the rotating hand 10 (ST
Along with 3), a counter (not shown) is reset to 0 (ST4) and the apparatus stands by. Pulse motor 2 one pulse at a time
Is driven in the X-axis direction (ST6), the photoelectric switch 1
Inspect the outputs of 5 and 16 to see if they have turned on. If not turned on, the counter is incremented (ST7) and further driven by one pulse. This is repeated until it is turned on (ST8), and the accumulated pulse number N at that time is stored.

Further, driving is performed one pulse at a time in the same direction (S
T9, ST10), the accumulated pulse number N at the time when the photoelectric switches 15, 16 are turned off (ST11) is obtained. N,
If M is obtained, the X-axis (expressed by the number of pulses) at the center point of the ON region is N + M / 2 with respect to the X-axis scanning start point A (ST12).

Further, the counter is always reset (ST1).
3) Then, the rotary hand 10 is positioned on standby at the Y-axis scanning start point B (ST14), and subsequently, the center point in the Y-axis direction is obtained in the same manner as the X-axis (ST15, ST16). afterwards,
The part 12 is returned to the storage position and the process ends (ST17). In the above description, the motor is moved one pulse at a time as the reference step. However, the present invention is not limited to this. For example, every two pulses or every ten pulses are possible. Further, the coarse feed is performed until the photoelectric switch is turned on, and an approximate on position is obtained. Next, it is possible to return only by one reference step, from which the reference step can be made finer, and the ON position can be determined precisely. By doing so, the detection time can be reduced.

(2) Three-Dimensional Offset Correction Main Work FIG. 7 is an explanatory diagram of the main work of three-dimensional offset correction of the present method example, where (a) is a plan view of the board 13 and (b) is (a).
(C) is a positioning diagram of the component gripping rotary hand 10 with respect to the photoelectric switch end in a section taken along line VIIbc-VIIbc in (a). FIG. 8 is a flowchart of the processing procedure for the same three-dimensional offset correction.

Here, 10 to 16 in FIG.
(B) The same members as those in the figure, and the same reference numerals are given to avoid duplication of the description. FIG. 7B shows a state in which the rotary hand 10 is positioned at the front surface of the photoelectric switch 15 in a state where the rotation position is 0 degree and is facing the scanning. After this, the photoelectric switch 16
And the offset amount with respect to the photoelectric switch 16 as the sensor is measured.

Next, as shown by the arrow in FIG.
The rotary hand 10 is rotated 180 degrees, the photoelectric switch 15 is scanned, and the offset amount is obtained. This offset amount,
An arbitrary rotation insertion point or rotation gripping point of the board 13 is confirmed based on the offset amounts (two pieces) obtained in FIG. 7B. FIG. 8 shows an operation flowchart at this time. As described in the two-dimensional preliminary correction operation, the photoelectric switch 1
5 (ST1), the offset of the photoelectric switch 16 is determined (ST2), the component 12 is gripped at the center point of the penetration holes 14a, 14b determined by two-dimensional correction, and the rotary hand 10 is transported. Position. Next, the rotary hand 10 is rotated 180 degrees (ST3), and the photoelectric switch 1 is turned on.
After obtaining the axis center offsets of 5 and 16 (ST4), the rotary hand 10 is rotated back by 180 degrees (ST5).

The above-described processing for calculating the position offset amount such as the inclination between the three-dimensional rotation axes and the deviation of the rotation axis is all performed by the computer 3.
The adjustment corresponding to the offset amount, which is processed by the program software of No. 3, adjusts the setting of the board 13 again with respect to the three-dimensional virtual coordinates, finely adjusts and tilts the omnidirectional tilt adjusting mechanism 37, and rotates the rotation axis of the rotary hand 10. Perform positioning correction work such as adjusting the posture.

The photoelectric switch 1 used here
As the optical fibers 5 and 16, generally commercially available fiber-type photoelectric switches in which the radiation optical fiber and the optical fiber are housed in one cylindrical case are used, but there is no need to be limited to this.
That is, any sensor that emits light from the photoelectric switch and changes the state of the switch depending on the intensity of the reflected light from the object may be used. For example, a number of thin emitting optical fibers may be arranged around a centrally located reflected light detecting optical fiber. However, when detection accuracy on the order of microns is required, it is preferable that the distance between the component 12 and the photoelectric switches 15 and 16 be as small as about 0.5 mm and that the slice level when the photoelectric switches 15 and 16 are turned on and off be higher. preferable. This is because the ON region becomes smaller and the reproducibility is improved.

In the above description, the case where the two photoelectric switches 15 and 16 are arranged at diagonal positions of the board 13 has been described, but the present invention is not limited to this. In other words, it goes without saying that any number (at least two) can have the same effect. For example, in the case of three switches, the third photoelectric switch may be the remaining one of the four corners or the center of the board 13. In this case, if the expansion and contraction of the board 13 is considered to be isotropic, the measurement accuracy can be improved by averaging the measurement data. Or if we consider the three measurement data independent,
The effect can be obtained to some extent on the expansion and contraction of the anisotropic board 13. In the case of four wires, for example, they may be installed at four corners.

In addition, in this embodiment, the component 1 to be inserted is
It has been described that the two rotary insertion holes 14 are used as the penetration holes 14a and 14b of the photoelectric switches 15 and 16,
Those skilled in the art can easily presume that this is not the case. For example, a pin that is driven into a mounting hole of the board 13 may be used. Further, it has been assumed that the rotary insertion hole 14 of the component 12 is regularly opened in the board 13, but even if it is irregular, as long as their positions are defined, it does not matter. In that case, the correction amount may be adjusted in proportion to the distance from the offset measurement position.

Further, although the motor has been described as a pulse motor in the present embodiment, an encoder for detecting the rotation angle of the DC motor or the AC motor is installed, and the same operation (input) as the pulse motor is performed by the motor driver. There is no problem as long as it is possible to perform (rotation only by the command pulse). In this case, rotation torque can be detected, and high torque can be expected.

Further, it has been described that the number of motor pulses at the time of motor scanning is measured by a register inside the computer, but it is naturally possible to measure by providing a separate hardware counter and register. In this case, the value of the register storing the pulse at the on / off point may be taken into the computer via the IO port.

[0081]

As described above, according to the present invention, it is possible to accurately position the rotary insertion hole at the center position of the rotary insertion hole even with respect to the offset during the rotation of the hand, which cannot be dealt with by the conventional method. In addition, the offset correction can be performed regardless of the hand rotation position by adding the offset amount measurement once.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a positioning device with a position correction function in which an example of the present device according to an embodiment of the present invention is integrated.

FIG. 2 is a diagram illustrating a preliminary operation of two-dimensional offset correction in an example of a method according to an embodiment of the present invention, in which (a) illustrates a concept of a relative positional relationship between a photoelectric switch adhered to a board and a rotating hand for gripping a component; Explanation plan view, (b) is the same.
FIG. 2 is a sectional view taken along line b-IIb.

FIG. 3 is a diagram illustrating the principle of measuring the on-region Ron.

FIG. 4 is an explanatory diagram of a measurement result of the above-mentioned deviation amount.

FIG. 5 is an explanatory diagram of a shift amount of the above-mentioned / adjacent interval.

FIG. 6 is a flowchart of the same two-dimensional offset correction preliminary processing procedure.

FIGS. 7A and 7B are explanatory diagrams of the main operation of the above-described three-dimensional offset correction, in which FIG. 7A is a plan view of a board, and FIG.
Middle VIIbc-Positioning diagram of the rotary hand for gripping the part with respect to the end of the photoelectric switch in the section taken along the line VIIbc.
(A) It is a 180-degree rotation figure of the rotary hand for component holding | grip with respect to the photoelectric switch end in the cross section taken along line VIIbc-VIIbc.

FIG. 8 is a flowchart of the above-described three-dimensional offset correction main processing procedure;

FIG. 9 is a system configuration diagram of a conventional positioning device with a two-dimensional position correction function.

FIGS. 10A and 10B are explanatory diagrams of a two-dimensional offset correction operation using the same as above, in which FIG. 10A is a conceptual explanatory diagram of a relative positional relationship between a board and a rotating hand for gripping parts, and FIG. FIG. 4 is a sectional view taken along line Xb-Xb.

[Explanation of symbols]

 T, T ': Positioning device with position offset correction function U: Rotating axis center position offset correction device 1: X-axis moving stage 2: X-axis driving motor 3: X-axis driving ball screw 4: Y-axis moving Stage 5 ... Y-axis drive motor 6 ... Y-axis drive ball screw 7 ... Z-axis movement stage 8 ... Z-axis drive motor 9 ... Z-axis drive ball screw 10 ... Rotating hand for component gripping 11 ... Part gripping Motor for opening and closing the tip of the rotary hand 12 ... Parts 13 ... Board with rotary insertion holes 14 ... Rotary insertion holes 14a, 14b ... Penetration holes 15, 16 ... Photoelectric switches 15a, 15b, 16a, 16b ... Core Alignment and holding member 20: Driver for driving the Y-axis drive motor 5 21: Driver for driving the X-axis drive motor 2 22a, 22b: Drive the motor Controllers 31 and 31 Amplifiers for photoelectric switches 15 and 16 32 Interface circuit 33 Computer (CPU) 34 for controlling the movement of motor 34 Rotating mechanism 35 Rotating mechanism driver 36 Rotating mechanism controller 37: omnidirectional tilt adjustment mechanism α: X-axis mechanism β: Y-axis mechanism γ: Z-axis mechanism δ: rotary hand mechanism for gripping parts δ1: slide table Pa, Pb: pulse signal

Continuing from the front page (72) Inventor Yasuhide Nishida 3-19-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Inventor Fumi Izumida 3-192-1, Nishi-Shinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Telephone Co., Ltd.

Claims (24)

[Claims] 1. An assembling device set on three-dimensional virtual coordinates.
Parts to be rotated and assembled / rotated by gripping and transporting the corresponding parts and tools to a plurality of rotation axis positioning target positions set in advance on the workpiece, and each planned rotation axis of the rotary hand means for tool gripping In performing the offset correction with respect to the position, the part / tool gripped by the part / tool gripping rotary hand means is placed on each sensor provided in alignment with a plurality of reference positions of the workpiece / workpiece. In addition, non-contact scanning is performed, and the on / off signal of the sensor is detected and the two-dimensional axis position of the sensor is measured and calculated from the center of the detection inner area determined and calculated. The part / tool gripping rotary hand means gripping with the axis facing is rotated around the axis, and the inclination of the three-dimensional axis of the sensor and the three-dimensional axis of the part / tool relative to each other and the deviation of the rotation axis, etc. Measures and calculates position offset amount Te calculated, calculates a correction amount a central axial position of the sensor as the origin of the offset operation for each axis of rotation positioning target, the rotation axis positioning positional offset correction method, characterized in that. 2. The method according to claim 1, wherein the sensor sticks out and protrudes from the work to be assembled / worked. 3. The method according to claim 1, wherein the sensor is a non-contact switch such as a photoelectric switch or a proximity switch. 4. The method according to claim 1, wherein the sensor is formed in a part / tool pseudo shape such as a cylindrical pin shape in appearance. 5. The rotary shaft center positioning position according to claim 1, wherein the non-contact scanning of the part / tool is a scanning in a direction orthogonal to a sensor end surface in a two-dimensional plane. Offset correction method. 6. The on / off signal of the sensor detects an on signal when passing the edge of the part / tool end face from outside to inside, and detects an off signal when passing from inside to outside. The method of correcting a rotational axis center position offset according to claim 1, 2, 3, 4, or 5. 7. The method of claim 1, 2, 3, 4, 5, or 6, wherein the calculation of the axial position of the sensor is performed by a computer. . 8. The assembly according to claim 1, wherein each of the articles to be assembled is a board in which rotary insertion holes, which are rotary assembly holes, are regularly or irregularly arranged at rotation axis center positioning target positions. 1, 2, 3, 4, 5, 6, or 7
3. The method of correcting a rotational axis center position offset described in 4. above. 9. The method according to claim 8, wherein the component is a pin that is rotatably inserted into a rotatable insertion hole that is provided through the component to be mounted. 10. The sensor according to claim 8, wherein said sensor is provided so as to penetrate and protrude into two or more through-holes of corner holes respectively arranged at a plurality of corners of a group of rotary assembling holes of an article to be mounted. Or the method of correcting a rotational axis positioning position offset described in 9 above. 11. A sensor according to claim 1, wherein said at least one corner hole is provided at a plurality of corners of said group of rotating assembly holes, and said center hole is provided at a center position of said group of rotating assembly holes. The rotational axis center positioning position offset correction method according to claim 8 or 9, wherein the method penetrates and projects through the through hole. 12. The rotary shaft center positioning position according to claim 10, wherein the sensor is centered on the hole axis of the through hole by the centering mounting and holding means so as to protrude therethrough. Offset correction method. 13. The rotation of the rotating hand means for gripping parts and tools around an axis is 180 ° rotation.
13. The method of correcting a rotational axis center position offset described in 8, 9, 10, 11 or 12. 14. The apparatus according to claim 1, wherein the axis shift position offset amount is a position offset amount before and after rotation of the rotary hand means for gripping parts and tools by 180 °. , 6, 7,
14. The method of correcting a rotational axis center position offset described in 8, 9, 10, 11, 12 or 13. 15. An X-axis and Y-axis motor for positioning on two-dimensional virtual coordinates, an X-axis and a Y-axis driver for driving the X-axis and Y-axis motors, and respective motor drive signals are generated. An X-axis and Y-axis controller, a computer for centrally controlling the driving of the X-axis and Y-axis motors, and a component that is combined and moved via the X-axis and Y-axis mechanism units by the rotation of the X-axis and Y-axis motors・ In a positioning device comprising a tool holding hand mechanism and a position offset correction function, two or more of assembled / workpieces set on three-dimensional virtual coordinates and a plurality of positioning target positions are specified in advance. And a sensor connected to a computer via an amplifier and an interface in sequence in the middle while the X is held by the hand mechanism for holding parts and tools.
A component in which the sensor detects the orthogonal movement in a two-dimensional plane parallel to the assembly / workpiece by the axis / Y-axis mechanism unit.
A tool, and a rotation mechanism for rotating the part / tool gripping hand mechanism that holds the part / tool around an axis and detecting the axis position of the part / tool by the sensor. Rotary axis positioning position offset correction device. 16. The sensor according to claim 15, wherein the center of the axis of the sensor is aligned with the centering and holding member so as to coincide with the axis of the through hole provided in the standard position. 3. The offset correction device according to claim 1, wherein 17. The apparatus according to claim 15, wherein the sensor is a non-contact switch such as a photoelectric switch or a proximity switch. 18. The optical switch according to claim 17, wherein the optical switch is a fiber-type optical switch in which a radiation optical fiber and a reflected light detection optical fiber are housed in a single cylindrical case. Rotary axis positioning position offset correction device. 19. The photoelectric switch according to claim 17, wherein the photoelectric switch is a reflection type photoelectric switch in which a number of thin optical fibers for radiation are arranged around an optical fiber for detecting reflected light located at the center. Rotary axis positioning position offset correction device. 20. The motor according to claim 15, wherein the motor is a pulse motor or a DC or AC motor with an encoder that rotates by an input command pulse issued from a motor driver.
10. The rotation axis center position offset correction device according to item 9. 21. The rotary mechanism according to claim 14, wherein the rotary mechanism is capable of rotating and stopping by 0 ° to 180 °.
21. The rotation axis center position offset correction device according to 8, 19 or 20. 22. A rotating mechanism driver for operating the rotating mechanism, a rotating mechanism controller for controlling the rotating mechanism driver, and a computer for controlling the rotating mechanism controller. The control drive system is connected to the control drive system.
22. The rotation axis center positioning position offset correction device according to 8, 19, 20 or 21. 23. The rotating mechanism according to claim 15, wherein the whole motor for opening and closing the hand tip for gripping parts and tools is rotatable integrally.
23. The rotation axis center position offset correction device according to 9, 20, 21, or 22. 24. A rotating mechanism is mounted on a slide table on which a hand mechanism for gripping parts and tools is mounted, through a tilt adjusting mechanism in all directions, and integrally with a motor for opening and closing the tip of the hand for gripping parts and tools. The rotational axis center positioning position offset correcting device according to claim 23, characterized in that: