JP3314348B2 - Positioning device with offset correction function and offset correction method for positioning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning device having an offset correction function using a robot and having a high-precision offset correction function, and a method of correcting an offset of the positioning device.

[0002]

2. Description of the Related Art A positioning device to which a robot hand is applied has been used as a device which fully automated the operation of inserting a cylindrical component into an insertion hole penetrating through an insertion board as an assembly target. . The configuration of such a conventional positioning device will be described with reference to the drawings.

FIG. 10 is an overall configuration diagram of a positioning device used to insert a cylindrical component into an insertion hole.
11A is a conceptual explanatory plan view of a positioning operation showing a relative positional relationship between an insertion board and a component gripping hand, and FIG.
Is a sectional view taken along line XIb-XIb.

[0004] In the figure, 1x, 1y, and 1z denote the X axis, respectively.
Y axis, Z axis pedestal, 2x, 2y, 2z are X axis, Y
Axis, Z-axis driving pulse motors, 3x, 3y, 3z are X-axis, Y-axis, Z-axis driving screw screws, 4x, 4
y, 4z are X-axis, Y-axis, Z-axis moving stages, 5
Denotes a component gripping hand, and 6 denotes a component gripping hand opening / closing drive motor fixed to the Z-axis moving stage 4z.

[0005] 7 is a component gripped by the gripping hand 5,
8 is an insertion board, 9 is an insertion hole through which a plurality of components 7 are inserted through the insertion board 8, 10 is a CPU as an arithmetic processing circuit, and 11x and 11y are for driving the X axis and the Y axis, respectively. Control circuit for pulse motors 2x, 2y, 12x, 12y
Are drive circuits for the X-axis and Y-axis drive pulse motors 2x and 2y, respectively. It should be noted that only the control systems for the X-axis and the Y-axis are shown in the drawing, and there is no description about the Z-axis, but it is assumed that a similar control system is provided.

In FIG. 10, an X-axis pedestal 1x fixed to a base surface (not shown) includes an X-axis driving pulse motor 2x.
The X-axis driving screw screw 3x, which is internally suspended by the above, is rotated forward and reverse to reciprocate the X-axis moving stage 4x in the X-axis direction in the figure. Similarly, a Y-axis pedestal 1y is orthogonally mounted on the X-axis moving stage 4x, and a Y-axis driving pulse motor 2y
Then, the Y-axis driving screw screw 3y, which is internally mounted, is rotated forward and backward to reciprocate the Y-axis moving stage 4y in the Y-axis direction in the figure.

[0007] Further, Z is placed on the Y-axis moving stage 1y.
The shaft base 1z is mounted upright, and the Z-axis driving pulse motor 2
The Z-axis driving screw screw 3z internally suspended by z rotates forward and reverse to reciprocate the Z-axis moving stage 4z in the Z-axis direction in the figure. A component gripping hand opening / closing drive motor 6 is fixed to the Z-axis movement stage 4z, and the base of the component / tool gripping hand 5 is directly connected to the component gripping hand opening / closing drive motor 6 axis. The component 7 is gripped at the tip of the component gripping hand 5.

Further, an insertion board 8 having a plurality of insertion holes 9 penetrating therethrough in parallel with the XY plane and facing the tip of the component gripping hand 5 is set and held on a virtual coordinate plane by appropriate means. The component 7 gripped at the tip of the component gripping hand 5 that moves up and down by driving the Z-axis driving pulse motor 2z is configured to be freely inserted into an arbitrary insertion hole 9. The insertion holes 9 are provided in the insertion board 8 so as to penetrate in a plane lattice shape while maintaining a predetermined interval between adjacent ones.

Next, a procedure for inserting a component 7 into a desired insertion hole 9 using a conventional positioning device will be described step by step. First, both the X-axis and Y-axis pulse motors 2x and 2y are driven to perform positioning at the origin of the virtual reference coordinate system stored in the CPU 10 in advance. This operation is performed more specifically as follows. The CPU 10 calculates a moving distance from an arbitrary component gripping hand 5 moving position to the origin position for each coordinate component, and sends a command signal Sa of a calculation result to the control circuit 11x.

The control circuit 11x generates a predetermined number of drive pulse signals Sb according to the moving direction and the distance for controlling the pulse motor 2x based on the command signal Sa resulting from the calculation, and sends the generated drive pulse signals Sb to the drive circuit 12x. . The drive circuit 12x converts the drive pulse signal Sb into a drive operation signal Sc having electric power necessary for driving the pulse motor 2x, and drives the pulse motor 2x to rotate by a predetermined angle.

The rotation of the X-axis driving pulse motor 2x is transmitted to the X-axis driving screw screw 3x, and the Y-axis and Z-axis mechanism parts mounted on the X-axis moving stage 4x and the component gripping hand 5 are rotated by the X-axis. It moves in parallel in the axial direction by a predetermined distance.

Next, the pulse motor 2y is similarly driven to rotate on the Y axis. When the component gripping hand 5 moves to the origin position, the origin position is detected using a microswitch or a photo sensor (not shown) attached to each of the moving stages 4x, 4y, and the CPU 10 controls the control circuits 11x, 1
A stop command is sent to 1y to stop driving the pulse motors 2x and 2y, and the CPU 10 reads the coordinates of the detected origin position and redetermines the origin position.

Next, the component gripping hand 5 moves to a supply position (not shown) of the component 7 to grip the component 7. The position of the insertion hole 9 in advance is the distance from the origin position of each axis (specifically, the number of drive pulses when a pulse motor is used, or the number of movement pulses detected by a rotary encoder or the like when a DC motor or AC motor is used). ), The component gripping hand 5 is moved to the target insertion hole 9 with reference to this.

FIGS. 11A and 11B show a state near the component gripping hand 5 immediately before the component 7 is inserted. Next, the component gripping hand 5 is driven to insert the component 7 into the insertion hole 9 corresponding to the target position plotted and set in the CPU 10 in advance. Usually, the opening of the insertion hole 9 and the tip of the component 7 are formed into a tapered shape, and even if a slight positioning error occurs, the error is absorbed and inserted.

In short, the component gripping hand 5 performs the operation of inserting the component 7 into the desired insertion hole 9 one after another through three steps of returning to the origin position, resetting the origin position, and moving to the target position. It is repeated.

As described above, in the conventional positioning device α, as long as the positioning operation is completely performed, if the relative position between the center axis of the component 7 and the center axis of the insertion hole 9 is almost coincident with each other, the Z axis The drive system in the direction is driven to insert the component 7 into the insertion hole 9.
Can be inserted smoothly.

[0017]

However, in the conventional positioning device α, since the resetting of the origin position is limited at the start of the operation, the insertion board due to, for example, temperature change, springback, loose displacement of the holding, etc. after the start of the operation. It was not possible to cope with the occurrence of a time-dependent set shift such as expansion, contraction, restoration, and holding shift of No. 8.

In addition, during the positioning of the insertion board 8 from the beginning, when the insertion board 8 is misaligned, and when the position of each of the insertion holes 9 is slightly deviated from a predetermined position and the insertion board 8 has an inaccurate working dimension, the component gripping hand is required. Even if 5 is moved to a predetermined position programmed in the CPU 10 in advance, the actual insertion position of the insertion hole 9 on the board 8 differs from the programmed position of the insertion hole 9 so that the component 7 is inserted into the insertion hole 9. The situation that it was not possible occurred.

Alternatively, if the sensors (not shown) attached to the moving stages 4x and 4y for detecting the origin position deviate from the correct position due to the change with time, the origin position and the reference coordinate system themselves are essentially relatively changed. Due to the displacement, there is a disadvantage that the component gripping hand 5 cannot perform the positioning operation at the position of the insertion hole 9 and the component 7 cannot be inserted into the insertion hole 9.

For this reason, when the conventional positioning device α is employed, the insertion and removal of the component 7 is not completely performed and a certain percentage of the components 7 are removed or dropped, and the reliability of the positioning device α itself is reduced. In the case of application to FA (factory automation) or deterioration of the end product, reduction of the yield of the final product is inevitable. Here, the present invention relates to a positioning apparatus with an offset correction function and a positioning apparatus which automatically corrects offset of position information due to individual assembling / machining position deviation or relative deviation of a reference coordinate system for each assembling / machining operation. It is an object of the present invention to provide a method for correcting an offset of a device.

[0021]

The above object can be attained by the present invention employing the following novel characteristic constitution means and method. That is, the first feature of the device of the present invention is as follows.
A part / tool gripping hand mechanism for gripping and positioning a part / tool at an arbitrary position of an assembly / workpiece set on virtual coordinates, and each X, X, Y, and Z axis drive motors that can drive the Y and Z axis movement stages, drive circuits that operate and drive the respective X, Y, and Z axis drive motors; A control circuit for controlling each of the control circuits, an arithmetic processing circuit for controlling the control circuits, and a drive circuit for driving the X and Y axis moving stages for moving the X and Y axes of the virtual coordinates. The pulse signals of the X and Y axis drive motors and the parts /
Simultaneously inputs a detection behavior signal from a position sensor mounted to detect a tool, counts and stores the pulse signals, and outputs the count results to the arithmetic processing circuit for performing an offset arithmetic processing. An offset correction circuit for inputting various operation signals commanded from a processing circuit, wherein the offset correction circuit controls each of the X and Y axis moving stages for moving the X and Y axes of the virtual coordinates. A pulse signal multiplexer configured to collectively select and switch a pair of pulse signals in the forward and reverse directions of the respective X and Y axis driving motors to be driven; and the respective X and Y axis drive selected by the pulse signal multiplexer. An up / down counter that inputs and subtracts pulse signals in the forward and reverse directions of the motor for
A gate signal multiplexer configured to selectively switch detection behavior signals input in parallel from a plurality of position sensors attached to the work to be assembled and the workpiece so that parts and tools can be detected, and connected to an output of the gate signal multiplexer; A first register to which the value of the up / down counter is written in response to the rise of the detection behavior signal; and a value to which the value of the up / down counter is written in response to the fall of the detection behavior signal which is connected to the output of the gate signal multiplexer. A positioning device with an offset correction function, comprising: a second register; and an I / O port for exchanging values of the first register and the second register and various operation signals with an arithmetic processing circuit. It is.

According to a second feature of the device of the present invention, a pulse signal of the motor for driving the X and Y axes in the first feature of the device invention is generated by the control circuit, and a pulse motor as the drive motor is provided. This is a positioning device with an offset correction function, which is a drive pulse signal for controlling the operation of the drive.

A third feature of the present invention is that the pulse signal of the X, Y axis driving motor in the first of the present invention is attached to a motor shaft of a DC motor or an AC motor as the driving motor. This is a positioning device with an offset correction function that is a moving pulse signal detected by a rotary encoder.

A fourth feature of the device of the present invention is a positioning device with an offset correction function, wherein the position sensor in the first, second or third feature of the device of the present invention is a photoelectric switch.

A first feature of the method of the present invention is that a part / tool gripping hand mechanism that grips a part / tool is attached to a work / assembly set on virtual coordinates and the X and Y axes of the virtual coordinates. In order to perform scanning and positioning to the target coordinate points plotted in advance along the line, and to perform the assembling and machining work of the parts and tools, a plurality of required representative positions of the assembling target and the work are scheduled in advance. By calculating the set deviation due to various factors from the set position on the virtual coordinates by detecting and indexing the base point of the required plurality of representative positions as appropriate by the detecting means, the pre-plotted assembly / processing A method for performing scan positioning after calculating and absorbing a relative positional deviation between a target coordinate point and a corresponding actual assembly / working point of the assembly / work corresponding to the target coordinate point, and appropriately detecting each base point of the required representative position. The detection index by means is The front of the photoelectric switch attached to each of the required representative positions of the work to be assembled / work corresponding to the arbitrary base position of the virtual coordinates is scanned by the component / tool gripped by the component / tool gripping hand mechanism. And an offset correction method for a positioning device, wherein the arithmetic behavior of coordinate components at a plurality of transition points at which a detection behavior signal output of the photoelectric switch transits between an ON state and an OFF state is calculated by proportional distribution.

A second feature of the method of the present invention is that a part / tool gripping hand mechanism for gripping a part / tool is attached to an assembly / work set on virtual coordinates in the X and Y axes of the virtual coordinates. In order to perform scanning and positioning to the target coordinate points plotted in advance along the line, and to perform the assembling and machining work of the parts and tools, a plurality of required representative positions of the assembling target and the work are scheduled in advance. By calculating the set deviation due to various factors from the set position on the virtual coordinates by detecting and indexing the base point of the required plurality of representative positions as appropriate by the detecting means, the pre-plotted assembly / processing A method for performing scan positioning after calculating and absorbing a relative positional deviation between a target coordinate point and a corresponding actual assembly / working point of the assembly / work corresponding to the target coordinate point, and appropriately detecting each base point of the required representative position. Detection index by means The said predetermined representative each position of the assembly-work products corresponding to any base point of the virtual coordinates, the parts and
The tool gripping hand mechanism scans with the front surface of the photoelectric switch grasped facing the front, and the detection behavior signal output of the photoelectric switch is proportionally allocated to the arithmetic mean of a plurality of coordinate components that transition between the ON state and the OFF state. This is an offset correction method for the positioning device calculated.

A third feature of the method of the present invention is that the base point of the required plurality of representative positions in the first or second feature of the method of the present invention is determined beforehand, and By calculating a set deviation due to various factors with the set position on the virtual coordinates where the required plurality of representative positions are scheduled, the assembly / machining target coordinate points plotted in advance and the assembly / processing A series of processes for calculating and absorbing the relative positional deviation of the actual assembling / working point of the work is the offset correction method of the positioning device, which is a program process.

[0028]

According to the present invention, since the above-mentioned means and method are employed, an arithmetic operation is performed on the basis of the actual assembling / working position of the part / tool measured by the photoelectric sensor to obtain the offset amount and correct the offset amount. By using one or a combination of hardware and software, accurate positioning and assembling / machining work can be performed at the assembling / machining center position even for assembling / work where various positional deviations such as expansion and contraction have occurred. Can be implemented.

[0029]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (Example of Apparatus) An example of an apparatus of the present invention will be described with reference to the drawings. FIG. 1 is a conceptual diagram of a configuration of a positioning device with an offset correction function showing an example of this device, FIG. 2 is a system block diagram showing an internal configuration of the offset correction circuit γ and an integrated command control system,
FIG. 3A is a plan view of the insertion board 8, and FIG.
FIG. 3A is a sectional view taken along line IIIb-IIIb, FIG. 4 is a diagram illustrating the principle of measurement of the ON region Ron, FIG. 5 is a diagram illustrating the measurement results of the same shift amount, and FIG. FIG. 7 is an explanatory view of the transfer amount.
It is a flowchart which shows an offset correction processing procedure.

In the figure, β is a positioning device with an offset correction function of the present example, γ is an offset correction circuit, and 13a, 1
3b is a photoelectric switch as a preferred example of a position sensor that emits detection behavior signals S1 and S2 that detect reflected light on the object surface and changes the output state, and 14a and 14b are detection behavior signals S1 of the photoelectric switches 13a and 13b, respectively. , S2 output, and 15 are control circuits 11x, 11
forward and reverse rotation drive pulse signals Sxfwd, Sxbwd and Syf from y
A pulse signal multiplexer 16 that selectively outputs any one of the inputs of wd · Sybwd, and a counter 16 counts the forward / reverse rotation drive pulse signals Sxfwd, Sxbwd, Syfwd, and Sybwd selectively output by the pulse signal multiplexer 15. This is an up-down counter.

Numeral 17 indicates that the photoelectric switches 13a and 13b are OF.
A register for temporarily storing the count value of the up / down counter 16 when the state changes from the F state to the ON state, and 17 ′ is a total number of the up / down counter 16 when the photoelectric switches 13a and 13b change from the ON state to the OFF state. A register for temporarily storing numerical values, 18 is amplifiers 14a and 14b
And a gate signal multiplexer for selecting and outputting one of the respective inputs from the gate.

Reference numeral 19 denotes an inverter for inverting the output signal level of the gate signal multiplexer 18, and reference numeral 20 transfers the temporarily stored count values of the registers 17, 17 'and various operation signals Sg, Sp, Srst, Srd to and from the CPU 10. This is an I / O port. The same members and blocks as those of the conventional example shown in FIG. 10 are denoted by the same reference numerals, and the description will not be repeated. Conventional example and pedestals 1x, 1y, 1z to insertion board 8
Until then, they have the same structure.

Each part has such a function, and the signal connection of each part will be described below. The detection behavior signals S1, detected by the photoelectric switches 13a, 13b
S2 is input to amplifiers 14a and 14b, respectively, and is amplified to a sufficient level. The outputs of the amplifiers 14a and 14b are input in parallel to the gate signal multiplexer 18, and one of the inputs is selected as an output in response to the gate signal selection operation signal Sg.

Various command signals S3 and S4 from the CPU 10
Are output independently to the control circuits 11x and 11y, respectively, and the control circuit 11x outputs the X-axis forward / reverse drive pulse signal Sxf.
Similarly, the control circuit 11y outputs Y-axis forward / reverse direction drive pulse signals Syfwd and Sybwd, respectively.

The outputs of the control circuits 11x and 11y are output to drive circuits 12x and 12y, respectively, and are converted into drive operation signals S5 and S6 to be used to drive the respective axis drive pulse motors 2x and 2x.
2y.

The X-axis forward / reverse drive pulse signal Sxf
wd, Sxbwd and the Y-axis forward / reverse drive pulse signal Syfwd,
Sybwd is input to the pulse signal multiplexer 15.
One of the forward / reverse drive pulse signals Sxfwd / Sxbwd and Syfwd / Sybwd is output by the input of the pulse signal selection operation signal Sp.

The output of the pulse signal multiplexer 15 is input to an addition input φup and a subtraction input φdn of an up / down counter 16 having a reset operation signal Srst input, and the result of addition / subtraction is output as binary data value signals S7 and S8. You. Outputs of the binary data value signals S7 and S8 of the up / down counter 16 are input to the registers 17 and 17 'in parallel.

The set operation signal Sse of the register 17 '
The t input is directly connected to the output of the gate signal multiplexer 18, and the set operation signal Sset input of the register 17 is connected to the output of the gate signal multiplexer 18 via the inverter 19. Register 1
The outputs of the binary data value signals S7 and S8 of 7, 17 'are connected to the CPU 10 via the I / O port 20.

(Example 1 of Method) The present example of the apparatus shows such a specific embodiment, and FIG. 3 shows a first example of the present invention applied to the example of the present apparatus.
A description will be given with reference to FIGS.

As shown in FIGS. 3 (a), 3 (b) and 5, an appropriate representative position on the surface of the insertion board 8 (here, the longest distance between the insertion holes 9 formed through the insertion board 8). The photoelectric switches 13a, 13b are respectively inserted into the insertion holes 9a, 9b) on the corners.
Is inserted so as to face the finger end 5 a of the component gripping hand 5. Next, the component 7 is gripped by the component gripping hand 5.

For the purpose of improving the detection accuracy, it is desirable to use a standard component having a relatively high dimensional accuracy as the component 7 to be gripped. However, it is naturally applicable to a general-purpose insertion component.

First, the component gripping hand 5 gripping the component 7 is positioned at the X-axis scanning start point Pxo1. The X-axis scanning start point Pxo1 depends on the amount of deformation of the insertion board 8, but here, as an example, the insertion holes 9a, 13b into which the photoelectric switches 13a, 13b are inserted by the diameter of the insertion holes 9a, 9b.
9b is located away from the center.

First, the input of the gate signal multiplexer 18 is changed to the first amplifier 1 by the gate signal selection operation signal Sg.
4a, similarly, the input of the pulse signal multiplexer 15 is switched to the X-axis forward / reverse direction driving pulse signals Sxfwd and Sxbwd by the pulse signal selection operation signal Sp, and the scanning is performed in the X-axis parallel direction by the first photoelectric switch 13a. Prepare. Next, an up / down counter 16 for counting and storing the number of movement pulses of the pulse motor 2x and the first and second registers 1
7, 17 'are reset by the reset operation signal Srst.

The CPU 10 sequentially rotates the X-axis driving pulse motor 2x via the control circuit 11x and the driving circuit 12x to start scanning in the X-axis parallel direction. Control circuit 11
The X-axis forward / reverse driving pulse signals Sxfwd and Sxbwd having the pulse waveform output from x are input to the addition input φup and the subtraction input φdn of the up / down counter 16 via the pulse signal multiplexer 15, and the number of moving pulses is calculated. Counting is performed.

When the photoelectric switch 13a reaches the point Pxa1 by scanning, the photoelectric switch 13a changes from the OFF state to the ON state, and sequentially passes through the amplifier 14a and the gate signal multiplexer 18 to become the set operation signal Sset as a rising signal. It is input to the set inputs of the registers 17, 17 '. Since the set inputs of the first and second registers 17, 17 'operate at the time of rising, as a result, the number of movement pulses Vxa1 at the time of the transition is written and held only in the second register 17'.

When the scanning is further continued and reaches the point Pxb1, the photoelectric switch 13a is again turned on from the ON state.
The state transits to the F state, passes through the amplifier 14a and the gate signal multiplexer 18 sequentially, and becomes a set operation signal Sset as a falling signal, which is input to the set inputs of the first and second registers 17, 17 '. The first and second registers 1
Since the set input of 7, 17 'operates at the time of rising,
As a result, the set operation signal Sset via the inverter 19
Of the second register 1 whose level is inverted to the rising signal
7, the number of movement pulses Vxb1 at the time of the transition is written and held.

Here, the CPU 10 sends the read operation signal Srd via the I / O port 20 to the first and second registers 17, 1
7 ', and the first and second registers 17, 17'
, The two moving pulse numbers Vxa1 and Vxb1 are transferred to the CPU 10 via the I / O port 20. This point Pxo1
→ Point Pxa1 → As a result of one scan via point Pxb1, the arithmetic average value of the number of movement pulses Vxa1 when passing point Pxa1 and the movement pulse Vxb1 when passing point Pxb1 ((Vxa1 + Vxb1))
/ 2) is obtained as the X coordinate of the center point of the ON region Ron.

Subsequently, after moving the component gripping hand 5 slightly in the Y-axis direction, the point Pxo2 → point Pxa2
→ The scanning in the X-axis direction via the point Pxb2 is started again,
The number of movement pulses Vxa2 and Vxb2 are stored in registers 17 and 17 '.
To the I / O port 20 by the read operation signal Srd.
To the CPU 10 via.

Next, the component gripping hand 5 is positioned at the Y-axis scanning start point Pyo1 on the X-axis, and the pulse signal selection operation signal Sp is switched to the input from the control circuit 11y, similarly to the scanning in the X-axis parallel direction. Point Pyo1 → Point Pya1 → Point Pyb1
Is performed in the Y-axis parallel direction, and is similarly transferred to the CPU 10 via the I / O port 20 by the read operation signal Srd. Further, scanning in the direction parallel to the Y-axis via point Pyo2 → point Pya2 → point Pyb2 is performed again in the same procedure.

The center point Pc (Xc, Yc) of the ON region Ron
Xc = (Vxa1 + Vxb1) is obtained by taking the arithmetic mean of each coordinate component transferred and stored in the CPU 10 to perform the scanning twice in the X-axis and Y-axis parallel directions as in the present method example. + Vxa2 + Vxb2) / 4 Yc = (Vya1 + Vyb1 + Vya2 + Vyb2) / 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.

Subsequently, the gate signal multiplexer 18
The gate signal selection operation signal Sg of the photoelectric switch 13b →
Switching to the input of the amplifier 14b, these series of scans are performed again for the insertion hole 9b.

In the case where the light emitting portions and the reflected light detecting portions of the photoelectric switches 13a and 13b are not on the same optical axis and the radiation direction is not axially symmetric, or the light radiation pattern from the light emitting portions is not isotropic. In such a case, the center point Pc of the ON region Ron
There is a shift due to the shift in the same plane between the mounting board 8 and the center point Ph of the insertion hole 9 where the photoelectric switches 13a and 13b are arranged.

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 13a and 13b only in advance, the center positions of the insertion holes 9a and 9b in which the photoelectric switches 13a and 13b are inserted can be accurately determined.

(Measurement Results) FIG. 5 is a measurement diagram of the ON region Ron of the photoelectric switch 13a. In creating this measurement diagram, the component 7 is fixed by the gripping of the component gripping hand 5 mounted on the three-axis moving stage 4x, 4y, 4z integrated with the photoelectric switch 13
a. Parts 7 for three-axis moving stage 4
The ON area Ron and OFF area Roff of the photoelectric switch 13a are measured while being moved by a small amount by a micrometer (not shown) attached to x, 4y, and 4z. The horizontal axis and the vertical axis in the figure indicate the X coordinate and the Y coordinate of the position of the component 7, respectively.

While observing with a microscope, the photoelectric switch 13
The three-axis fine movement stages 4x, 4y, 4z are finely adjusted so that the centers of the insertion holes 9a, 9b into which the a, 13b are inserted and the photoelectric switches 13a, 13b, respectively, and the three-axis fine movement stages 4x, 4y at that time. , 4z at the photoelectric switch 13
a, 13b are the centers of the insertion holes 9a, 9b.
This center was set as the base point of the XY coordinate system. As the component 7, a ferrule for an optical fiber was employed.

The distance l between the component 7 and the photoelectric switch 13a is 1 =
The first measurement value at 0.5 mm is indicated by a circle in the figure, and the second measurement value is indicated by a cross 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, indicates the center point Pc of the ON region Ron, and the mark ● in the figure.
The mark is the center point Ph of the insertion hole 9a in which the photoelectric switch 13a is inserted. The center point Pc (marked by ◎ in the figure) of the ON region Ron is shifted by 10 μm in the X-axis direction and 30 μm in the Y-axis direction from the center point Ph (marked by ● in the figure) of the insertion holes 9a and 9b.

Due to the structure of the photoelectric switch 13a, the ON region R
ON center point Pc (marked with ◎ in the figure) and insertion hole 9a center point Ph
(● in the figure) does not match. However, since this distance difference is constant if the type of the photoelectric switch 13a employed is the same, the distance difference is measured and subtracted in advance in this way, so that the insertion hole 9a in which the photoelectric switch 13a is inserted is obtained. The actual center position is determined. Since the distance difference is of the order of several tens of μm in the measured values of FIG. 5, the center point Ph of the insertion holes 9a and 9b with an accuracy of several tens of μm (● in the figure)
The exact position of the mark is required.

FIG. 6 shows a virtual coordinate axis for explaining a method of correcting the position of the insertion hole 9 and a relative arrangement of the insertion board 8 set thereon. Here, it is assumed that the insertion holes 9 are arranged in a plane lattice shape in which the adjacent intervals are constant. The insertion board 8 expands and contracts slightly in the plane direction due to a temperature change and other external factors, and as shown in FIG.
a, the center position of the insertion holes 9a, 9b through which the 13b is inserted,
Positions P1 (X1, Y1) and P2 (X
2, Y2) to Pn1 (Xn1, Yn1), Pn2 (Xn2, Yn)
Assume that they have moved to 2).

Similarly, the distance between adjacent insertion holes 9 in the X-axis and Y-axis directions before offset correction is (dx, dy).
(Dnx, dny). Here, the arrow in the figure indicates a transition from before correction to after correction. The insertion board 8 has a large number of nx insertion holes 9 in the X-axis direction and ny insertion holes 9 in the Y-axis direction in a lattice pattern on the XY plane. still,
For reference, the total number of the insertion holes 9 is the photoelectric switch 13.
Since a and 13b are inserted at two places, nx × ny-2.

The adjacent mutual spacing (dnx, dny) in the X-axis and Y-axis directions of the insertion hole 9 after the shift is dnx = (Xn2-Xn1) / (nx-1) dny = (yn2-yn1) / (Ny-1) is calculated.

Similarly, the insertion hole Pnm (Xn, Ym) after the shift.
Xn = Xn1 + (n-1) dnx ... (2) Ym = Yn1 + (ny-m) dny ... (3) Here, the insertion hole closest to the origin in the figure is P
11, and an arbitrary insertion hole is P nm.

The calculation result of the position of the insertion hole 9 after the shift calculated in the CPU 10 by the formulas (2) and (3) is sent to the control circuits 11x and 11y.
x and 11y are drive pulse signals Sxfwd, Sxbwd, Syfwd,
Sybwd is sent to the driving circuits 12x and 12y, and the driving circuit 1
2x and 12y are the drive pulse signals Sxfwd, Sxbwd, S
The drive operation signals S5 and S6 corresponding to yfwd and Sybwd are applied to the respective pulse motors 2x and 2y by applying drive pulse voltages of a number corresponding to the shift distance, and are rotationally driven to the insertion hole 9 after the shift. The component gripping hand 5 is moved.

Here, the case where the insertion board 8 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, etc.
Offset correction is possible from Expressions (2) and (3) just like in this example.

FIG. 7 is a flowchart showing the offset correction processing procedure. Since there are at least two or more photoelectric switches 13a and 13b, the closed loop in FIG.
Times. First, one photoelectric switch 13
a The front surface of [see step I] is scanned by the component gripping hand 5 [see step II], and the center point Pc of the ON region Ron of the photoelectric switch 13a is measured [see step III].

Next, the previously measured photoelectric switch 13a
The center point Ph of the insertion hole 9a in which
Then, the center position of the insertion hole 9a is determined based on the difference value from the center point Pc (see step IV). This is performed for all of the plurality of photoelectric switches 13a and 13b [see step V].
From the center positions of the insertion holes 9a and 9b into which the photoelectric switches 13a and 13b are inserted, the center position of an arbitrary insertion hole 9 is obtained. Subsequently, the mutual spacing dnx, dny of the shifted insertion holes 9, 9a, 9b is calculated [see step VI], and the coordinates (Xn, Y) of the shifted insertion holes 9, 9a, 9b are further calculated.
m) is calculated [see step VII].

The photoelectric switches 13a and 13b used as the position sensors employed here are commercially available fiber type photoelectric switches in which a radiation optical fiber and a reflection detection optical fiber are housed in a single hollow cylindrical container. However, there is no need to be limited to this. That is, any type of sensor may be employed as long as it has a light projecting function and a reflected light detecting function.

As an example of this, it is also possible to apply a combination of a light guiding means, a light source and an optical sensor in which a plurality of irradiation light guiding optical fibers are arranged around a reflected light detecting optical fiber in cross section. However, when detection accuracy on the order of microns is required, the component 7 and the photoelectric switch 1 are required.
3a and 13b are close to each other so that the distance between them is about 0.5 mm, and the photoelectric switches 13a and 13b
It is desirable to increase the slice level at the time of the ON / OFF transition of b as much as possible.

In the above description, two photoelectric switches 13a and 13b are inserted into the insertion holes 9 penetrating through the insertion board 8, particularly the diagonal insertion holes 9a and 9b. Although the case has been described, three or more photoelectric switches may be used at the representative positions as appropriate. Of course,
These photoelectric switches 13a and 13b are connected to the insertion board 8
It is desirable to install it on the peripheral surface as much as possible in order to maximize the absorption of the error due to the expansion and contraction of.

In the present embodiment, a cylindrical pin is used as an example of the component 7 to be inserted into the insertion hole 9, but the structure and shape of the component 7 are not limited to this. As an example, the component 7 may be a ferrule of an optical fiber cable, and an optical fiber cable connector may be used instead of the insertion hole 9 formed through the insertion board 8.

In this embodiment, the photoelectric switches 13a,
Although the method of arranging the switch 13b on the insertion board 8 has been described, the photoelectric switch 13a, 13b is gripped by the component gripping hand 5 during the offset compensation operation, and
It is also possible to detect the penetration positions of a and 9b. In this method, the off regions Roff of the photoelectric switches 13a and 13b are used.
Is detected, the center position of the insertion hole 9 is obtained. Subsequent operations may be performed in exactly the same operation procedure as when the photoelectric switches 13a and 13b are arranged on the insertion board 8.

Further, it has been assumed that the insertion holes 9 of the components 7 are provided in the insertion board 8 in a grid pattern at equal intervals adjacent to each other. If it is defined, it does not matter. In this case, the correction amount may be adjusted by performing proportional distribution according to the distance from the offset measurement position.

That is, the dimensional change rate α of the insertion board in the X-axis direction
The dimensional change rates αy of the inserted board in the x and Y axis directions are (Xn2−Xn1) / (X2−X1), (Yn2−Yn1) /
(Y2-Y1), the X coordinate Xnb and the Y coordinate Ynb of the position where the part 7 is to be inserted are respectively Given by

In this embodiment, the pulse motors 2x, 2y and 2z are used as the driving motors.
A rotary encoder is directly connected to the motor shaft, and the rotation of the rotary encoder is amplified as a moving pulse signal by amplifying an output of a phototransistor combined with an LED, and the pulse signal is converted into a drive pulse signal Sxfwd, Sxb of this embodiment.
It is a matter of course that the movement control is performed by inputting to the up / down counter 16 via the pulse signal multiplexer 15 instead of wd, Syfwd, and Sybwd, and employing a DC motor or an AC motor.

Further, although the present invention has been described only with respect to the part to be assembled such as the insertion board 8 and the part 7, the workpiece and the tool can be respectively used instead. Is applicable as a power tool to be electrically connected to the CPU 10 for processing positioning of a tool with respect to a workpiece.

(Example 2 of Method) An example of an apparatus used for performing the second example of the present invention will be described with reference to the drawings. FIG. 8 is a system block diagram showing an integrated command control system of the device example. In the figure, 2
0 'is an I / O port. Note that the same blocks as those of the integrated command control system in the example of the apparatus shown in FIG.

In this example of the apparatus, since the offset correction amount is obtained by a program stored in the CPU 10, the count of the number of drive pulses of the pulse motors 2x and 2y for driving the X-axis and Y-axis is C
Since it is performed by the software of the program of the PU 10, the hardware offset correction circuit γ in the above-described device example becomes unnecessary, and the outputs of the photoelectric switches 13a and 13b are used as detection circuits by the I / O port 20 '.
It is only taken into PU10.

Therefore, the configuration for driving the X-axis driving pulse motor 2x and the Y-axis driving pulse motor 2y is the same as that of FIG. That is, the offset correction circuit γ has been deleted, and the detection behavior signals S1 and S2 amplified by the amplifiers 14a and 14b connected to the photoelectric switches 13a and 13b, respectively, are used for the newly installed I / O port 2.
0 '. Photoelectric switches 13a and 13
The on / off detection behavior signals S1 and S2 of b are taken into the CPU 10 through the I / O port 20 '.

Based on the above, the execution procedure of the second example of the present invention will be described with reference to the drawings. FIG. 9 shows a flowchart of an execution procedure for detection by software of the example method.

In the figure, the center point of the ON area in the X-axis direction is obtained. First, the count value N of a counter (not shown) is reset to 0 (see step I), then the hand 5 holding the component 7 is positioned at the X-axis scanning start point Px01 [see step II], and the pulse motor is pulsed one pulse at a time. 2x to X
After driving in the axial direction (see step III), the output of the photoelectric switch 13a is inspected to see whether it is turned on (see step V). If it is not turned on, the counter is incremented before that (see step IV), and further driven by one pulse (see step III). This is repeated until it is turned on, and the accumulated pulse number N at that time is stored.

The count value M of a counter (not shown) is reset (see step VI), and the pulse is driven one pulse at a time in the same direction (see step VII). This time, the accumulation when the photoelectric switch 13b is turned off (see step IX) is performed. The number of pulses M is obtained [see step IIX]. If N and M are obtained, the X-axis (expressed by the number of pulses) at the center point of the ON region becomes N + (M / 2) based on the X-axis scanning start point Px01 [see step X]. The center point in the Y-axis direction is obtained in the same manner as the X-axis. The same operation is performed for the photoelectric switch 13b.

In the above description, the reference step (step)
Although the motors 2x and 2y are moved one pulse at a time, the invention is not limited to this. For example, every two pulses or every ten pulses are possible. Further, the photoelectric switches 13a, 13
Until b is turned on, the coarse feed is performed, and the 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.

[0082]

As described above, by adopting the present invention,
It is not possible to accurately adjust the center position of the insertion hole even for insertion boards that have expanded or contracted due to various external factors such as aging or temperature changes, which could not be handled as long as conventional methods and devices were adopted. Achieve positioning work.

Further, in order to implement this, the detection can be performed only by employing a small photoelectric switch which is a component having substantially the same shape and the same outer diameter as the component to be inserted. If this is the case, the detection time will be shortened, and a more compact and economical configuration for hardware detection will be realized, which has the advantage of high practicality.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of the overall configuration of a positioning and inserting device with an offset correction function in an example of the device of the present invention.

FIG. 2 is a system block diagram showing an internal configuration of an offset correction circuit γ and an integrated command control system.

FIG. 3 (a) is a conceptual explanatory plan view of a relative positional relationship between the same and the insertion board and the component gripping hand, and FIG. 3 (b) is a IIIb-I.
FIG. 2 is a sectional view taken along line IIb.

FIG. 4 is a diagram illustrating the principle of measuring the on-region Ron.

FIG. 5 is an explanatory diagram of a measurement result of the above-described deviation amount.

FIG. 6 is an explanatory diagram of a shift amount of the above-mentioned / adjacent interval.

FIG. 7 is a flowchart illustrating an offset correction processing procedure according to the embodiment.

FIG. 8 is a system block diagram showing an integrated command control system of an example of an apparatus used in performing a second example of the method of the present invention.

FIG. 9 is a flowchart of a program process for finding a center point of the off-region Ron in the X-axis direction.

FIG. 10 is a conceptual diagram of the entire configuration of a conventional positioning and attaching device.

FIG. 11A is a conceptual explanatory plan view of the relative positional relationship between the insertion board and the component gripping hand, and FIG.
FIG. 11 is a sectional view taken along line XIb.

[Explanation of symbols]

α: Positioning device β: Positioning device with offset correction function γ: Offset correction circuit φup: Addition input φdn: Subtraction input Pc: Center point of on-region Ron Ph: Insertion holes 9a, 9b into which photoelectric switches 13a, 13b are inserted Roff ... Off area Ron ... On area Sg ... Gate signal selection operation signal Sp ... Pulse signal selection operation signal Sset ... Set operation signal Srst ... Reset operation signal Srd ... Read operation signal Sxfwd ... X-axis positive direction drive pulse signal Sxbwd ... X-axis reverse drive pulse signal Syfwd ... Y-axis forward drive pulse signal Sybwd ... Y-axis reverse drive pulse signal 1x, 1y, 1z ... Pedestal 2x, 2y, 2z ... Drive pulse motor 3x, 3y, 3z ... Drive Screws 4x, 4y, 4z Moving stage 5 Component gripping hand 6 Component opening / closing hand open / close drive motor 7 Component 8 Insertion Mode 9, 9a, 9b insertion hole 10 CPU 11x, 11y, 11z control circuit 12x, 12y, 12z drive circuit 13a, 13b photoelectric switch 14a, 14b amplifier 15 pulse signal multiplexer 16 up / down Counter 17, 17 'Register 18 Gate signal multiplexer 19 Inverter 20, 20' I / O port

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-113607 (JP, A) JP-A-1-103708 (JP, A) JP-A-59-124550 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G05D 3/00-3/20 B23Q 15/00-15/28

Claims (7)

(57) [Claims] 1. A part / tool gripping hand mechanism for gripping and positioning a part / tool at an arbitrary position of an assembling / workpiece set on virtual coordinates, and a combination configuration including the part / tool gripping hand mechanism mounted thereon. X, Y, and Z axis driving motors that can drive the respective X, Y, and Z axis moving stages,
A drive circuit for operating each of the Y- and Z-axis drive motors; a control circuit for controlling the drive circuit; an arithmetic processing circuit for controlling the control circuit; Each X, Y driving each X, Y axis moving stage for moving the X, Y axis of virtual coordinates
A pulse signal of the Y-axis driving motor and a detection behavior signal from a position sensor attached to the assembly / work to detect the part / tool so as to be detectable are simultaneously inputted, and the pulse signals are respectively counted and stored. An offset correction circuit that gradually outputs the count result to the arithmetic processing circuit that performs offset arithmetic processing and that receives various operation signals commanded from the arithmetic processing circuit. Each of the X and Y moving the X and Y axes of the virtual coordinates
A pulse signal multiplexer configured to collectively select and switch a pair of pulse signals in the forward and reverse directions of the respective X and Y axis driving motors for driving the Y-axis moving stage; and the pulse signal multiplexers selected by the pulse signal multiplexer. Up / down counters for inputting and subtracting pulse signals in the forward and reverse directions of the X and Y axis drive motors, respectively, and a plurality of position sensors attached to the assembly / work to detect the parts / tools in a parallel manner. A gate signal multiplexer configured to selectively switch an input detection behavior signal; a first register connected to an output of the gate signal multiplexer to which a value of the up / down counter is written according to a rise of the detection behavior signal; The signal is connected to the output of the signal multiplexer, and the falling edge of the detection behavior signal causes A second register to which a value of an up / down counter is written; and an I / O port configured to exchange values of the first register and the second register and various operation signals with an arithmetic processing circuit. A positioning device with an offset correction function. 2. The apparatus according to claim 1, wherein the pulse signal of the X, Y-axis driving motor is a driving pulse signal generated by the control circuit for controlling the driving of a pulse motor as the driving motor. The positioning device with an offset correction function according to claim 1. 3. A pulse signal of the motor for driving the X and Y axes is a moving pulse signal detected by a rotary encoder mounted on a motor shaft of a DC motor or an AC motor as the driving motor. Claim 1
A positioning device with an offset correction function according to the description. 4. The positioning device with an offset correction function according to claim 1, wherein said position sensor is a photoelectric switch. 5. A target, in which a part / tool gripping hand mechanism is gripped on an assembly / workpiece set on virtual coordinates, in advance along the X and Y axes of the virtual coordinates. Scan to the coordinate points and assemble the parts and tools.
In order to perform the processing operation, in advance, a set deviation due to various factors with a set position on the virtual coordinates at which the required plurality of representative positions of the work to be assembled / worked is scheduled, By calculating the base point after detecting and indexing it by the detection means as appropriate, the relative coordinates of the previously plotted target coordinate point for assembly / working and the actual assembly / working point of the assembly / work corresponding thereto are obtained. A method of performing scanning positioning after calculating and absorbing a position shift, wherein the detection index of each base point of the required representative position by an appropriate detection unit is adjusted to correspond to an arbitrary base point position of the virtual coordinates. The front of the photoelectric switch attached to each of the required representative positions of the product is scanned with the component / tool gripped by the component / tool gripping hand mechanism, and the detection behavior signal output of the photoelectric switch is turned on and off. And calculating the arithmetic mean of the coordinate components of the plurality of transition points that make a transition in the form of a proportional distribution. 6. A target in which a part / tool gripping hand mechanism holding a part / tool is plotted in advance along the X and Y axes of the virtual coordinate on an assembly / workpiece set on virtual coordinates. Scan to the coordinate points and assemble the parts and tools.
In order to perform the processing operation, in advance, a set deviation due to various factors with a set position on the virtual coordinates at which the required plurality of representative positions of the work to be assembled / worked is scheduled, By calculating the base point after detecting and indexing it by the detection means as appropriate, the relative coordinates of the previously plotted target coordinate point for assembly / working and the actual assembly / working point of the assembly / work corresponding thereto are obtained. A method of scanning and positioning after calculating and absorbing a positional deviation, wherein detection indexing of each base point of the required representative position by an appropriate detection unit is performed by the mounting / machining corresponding to an arbitrary base point position of the virtual coordinates. The required representative positions of the product are scanned with the front surface of the photoelectric switch gripped by the component / tool gripping hand mechanism facing, and the detection behavior signal output of the photoelectric switch is turned on and OFF.
An offset correction method for a positioning device, wherein an arithmetic mean of a plurality of coordinate components that transit to an F state is calculated by proportional distribution. 7. A method according to claim 1, further comprising: determining a base point of said plurality of required representative positions beforehand; and determining a plurality of required representative positions of said work to be assembled / worked by various factors with a predetermined set position on said virtual coordinates. A series of processes for calculating, correcting, and absorbing the relative displacement between the target coordinate point for assembly / working plotted in advance and the actual assembly / working point of the assembly / workpiece corresponding thereto, by calculating the set shift. 7. The offset correction method for a positioning device according to claim 5, wherein is a program process.