JPH07104142B2 - Drive device by work coordinate system - Google Patents

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a device for driving a driven device such as an XY table in response to a command from an input device such as a joystick.

(Background of the Invention) XY driven by an X-direction motor and a Y-direction motor
When measuring a work (measurement object) with a projector equipped with a stage or a tool microscope, the stage driving device is operated while observing the work with the observing device of the measuring device, and the measurement point on the work is the reference of the observing device. Sequentially match the points, for example, the crosshairs on the projection screen or reticle, and set the coordinate values of those points to X.
-It is executed by reading with a linear encoder or the like provided on the Y stage. The driving device is equipped with an input device (for example, a joystick) having an operating member for driving the stage in any X and Y directions.

Most of the dimensions to be measured are parallel to the coordinate axis of the workpiece coordinate system set by the reference point or reference surface on the workpiece.

In order to obtain the dimension to be measured directly from the reading of the linear encoder or by a simple calculation called the difference between the readings at two points, the length to be measured is the moving direction of the stage, that is, the coordinate axis of the machine coordinate system. Since it must be parallel to the X-axis or the Y-axis, the coordinate axis (x
The direction of the work is adjusted so that the axis (or the y-axis) becomes parallel to the moving direction of the stage, that is, the coordinate axis of the machine coordinate system. FIG. 5 shows a state adjusted in this way.
The coordinate axes of the mechanical coordinate system of the stage 12 and the coordinate axes of the work coordinate system set on the work 13 are parallel. Therefore, the stage movement for measuring the dimensions Δx and Δy parallel to the coordinate axis of the workpiece coordinate system should be performed only in the X-axis direction for the dimension Δx.
Regarding the dimension Δy, only the Y-axis direction is required.

Recently, due to the digitization of stage movement reading and the development of computers, the coordinate values of the machine coordinate system at each measurement point are directly taken into the computer and processed to obtain the necessary work size. .
In this case, it is no longer necessary that the length to be measured is parallel to the moving direction of the stage, since complicated calculations are easy. Such a state is shown in FIG. Here, the mechanical axis of the stage 12 and the coordinate axis of the work coordinate system are inclined by an angle θ. For example the dimensions △ x coordinate values of the machine coordinate system of the point A and point _{B (X A, Y A)} , (X B, Y B) from It is obtained by calculating. Therefore, the adjustment work of adjusting the work coordinate system to the machine coordinate system is unnecessary, but it is necessary to move the stage in the X-axis direction and the Y-axis direction in order to measure the dimension parallel to the coordinate axis of the work coordinate system. . Therefore, the stage may be moved alternately in the X-axis direction and the Y-axis direction, but it is advantageous to move the stage in the coordinate axis direction of the work coordinate system because the measurement time can be shortened. It must be driven simultaneously in the axial direction and the Y-axis direction.

That is, in the former case (FIG. 5), the operation for giving a drive command to the stage is easy because it is selective in the X-axis direction or the Y-axis direction, but in the latter case (FIG. 6), the X-direction of the stage is easy.
A drive command with a speed ratio V _Y / V _X = tan θ according to the angle θ must be given in the axial direction and the Y-axis direction.

A joystick is often used as an input device for giving a drive command to the stage. Normally, the joystick commands the moving direction and the moving speed based on the tilt angle of the tilting direction of the operating lever which is normally in the neutral position. 1
In a drive device that controls the movement of the stage in the X-axis direction or the Y-axis direction with two joysticks,
Two joysticks corresponding to the axial direction are required, and the two joysticks have a ratio of their inclination angles to ta.
Since it is operated so as to be nθ, it is difficult to perform fine stage control. In a drive device having a joystick capable of controlling the X-axis direction and the Y-axis direction by one joystick, the operation lever of the joystick can be tilted in any direction, and the operation lever is tilted in the direction of the angle φ by the angle Ψ. The command values of V _X = (Ψ) cosφ and V _Y = (Ψ) sin φ are given to the X-axis direction and the Y-axis direction of the time stage, respectively. That is, the command value V _X is input to the X-axis direction drive device, and the command value V _Y is input to the Y-axis direction drive member. Where V
(Ψ) is a command speed determined by the value of Ψ.

Since the speed ratio between the X-axis direction and the Y-axis direction is V _Y / V _X = tanφ,
In order to move the stage parallel to the x-axis of the work coordinate system, it is sufficient to tilt the operating lever of the joystick in the angle θ direction, but this is not easy either. Furthermore, in order to facilitate fine feed control of the stage, a non-linear speed characteristic is often given to the tilt angle of the operating lever of the Joystick, but in this case, the tilting direction of the operating lever of the Joystick and the moving direction of the stage Becomes more difficult because it does not necessarily match.

In addition, the three-dimensional coordinate values of the probe that can move along the X-axis, Y-axis, and Z-axis of the mechanical coordinate system are transferred to the computer by an electric signal generated by the contact of the probe contacting the workpiece. The same situation as described above is also present in the coordinate measuring machine that reads and calculates the required dimensions. However, since the coordinate measuring machine has three coordinate values, in addition to operating the front and back and left and right of the operation lever of the joystick, the drive command to the third axis (Z axis) is given, so the knob of the operation lever of the joystick is rotated. Either a structure in which the command is output by this is used, or another joystick must be added for the command of the third axis.

Unlike a two-dimensional stage, the object to be measured by the coordinate measuring machine is not always in the horizontal plane (X-Y plane), but the Z-axis is added, so that the measurement target is often the Y-Z plane or the Z-X plane. There is a case where measurement is performed on a substantially vertical side surface, and it is sometimes parallel to one of the x-axis, y-axis, and z-axis that is set on the work, but not to the other axes. In some cases, measurement is performed on an inclined surface that is not parallel to the surface or any of the three coordinate axes. In such cases, in order to perform a movement along the surface to be measured or a movement perpendicular to the surface, it is generally necessary to control the three axes simultaneously with an appropriate ratio. The drawback was that it had to be said to be impossible.

Note that these drawbacks are the same as in the case where a track ball having a built-in encoder or a simple knob attached to the encoder is used to instruct the movement amount, instead of the speed command being given by the joystick.

(Object of the Invention) The present invention solves the problems as described above, and realizes a drive device that is easily given a drive command by a work coordinate system arbitrarily set on a work, and
The object is to obtain a drive device based on a work coordinate system that facilitates measurement operation.

(Summary of the Invention) The present invention provides a drive command to the drive means based on drive means for driving the driven member and a drive signal for driving the driven member along the coordinate axes of the first coordinate system. And a drive command means, wherein the drive command means converts the drive signal from the first coordinate system to a second coordinate system, and drives the driven member to coordinate axes of the second coordinate system. The drive command to the drive means so as to move the drive means along with, and a blocking means for blocking the movement of the driven member in an arbitrarily selected direction in the coordinate axes of the second coordinate system. It is a drive device based on a featured work coordinate system.

(Embodiment) The present invention will be described based on the embodiment shown in the drawings. FIG. 1 is a block diagram of the first embodiment of the present invention.
The X-axis encoder 1 and the Y-axis encoder 2 output coordinate signals corresponding to the X and Y coordinate values of the mechanical coordinate system defined by the driving direction of the XY stage 12. The coordinate capturing switch 3 is turned on after the measuring point on the work is aligned with the reference point of the observing device (not shown), for example, the cross line of the projection screen or reticle, and functions as position measuring means. The switch circuit 4 receives the coordinate signal from the X-axis encoder 1 and the Y-axis encoder 2 when the coordinate fetch signal (generated when the coordinate fetch switch is turned on) is input from the coordinate fetch switch 3 to the micro computer 6. It functions as a selection means for inputting into. A two-dimensional coordinate value input device 5 is formed by the above X-axis encoder 1, Y-axis encoder 2, coordinate acquisition switch 3, and switch circuit 4. The microcomputer 6 calculates a coordinate conversion matrix from the input coordinate signal.

The joystick 7 has an operation lever (not shown), and the speed command values V _X = √ (Ψ) · cos θ, V _Y = V (for the X-axis and the Y-axis according to the tilt direction φ and the tilt angle Ψ of the operation lever. Ψ) ・ sin
It functions as a speed command unit that outputs θ. analog·
Digital converter (hereinafter referred to as A / D converter) 8
a and 8b perform analog-to-digital conversion on the command values V _X and V _Y , respectively, and output digital command values V _XD and V _YD . The microcomputer 6 uses the coordinate conversion matrix that has previously obtained the digital command values V _XD and V _YD to determine the command values V _xD and V _{yD in the} machine coordinate system.
It functions as a conversion means for converting to and outputting.

Also, a first clamp switch 100 and a second clamp switch 101 are connected to the micro computer 6. When the first clamp switch 100 is turned on, the first signal is output, the microcomputer 6 having input the first signal ignores the command value V _YD , and when the second clamp switch 101 is turned on, the second signal is output, and the second signal is output. The microcomputer 6 having input the signal ignores the command value V _XD .

The command values V _xD and V _yD are digital / analog converters (hereinafter D
/ A converter) 9a, 9b are input and converted into analog command values V _x , V _y . The analog command values V _x and V _y are input to the motor drive circuits 10a and 10b, respectively. Motor drive circuit 10
Reference numerals a and 10b respectively drive an X-axis motor 11a for driving the XY stage 12 in the X direction and a Y-axis motor 11b for driving the Y-direction in the Y direction.

Since the X-axis motor 11a and the Y-axis motor 11b cooperate to move the XY stage 1 based on the work coordinate system, the joystick 7 is eventually driven by a drive unit according to the mechanical coordinate system.
This means that the drive device has been converted into a drive device according to the work coordinate system obtained by the coordinate value input device 5.

Therefore, if the operation lever of the joystick 7 is tilted in the X-axis direction, the stage moves in the x-axis direction of the work coordinate system, and if the operation lever is tilted in the Y-axis direction, the stage moves in the y-axis direction of the work coordinate system. Move in the direction.

Next, the operation of the microcomputer 6 will be described in detail with reference to the flow chart of FIG. This flow chart process is continuously or repeatedly executed at regular intervals.

As shown in FIG. 2, the microcomputer 6 inputs the coordinate value for determining the matrix from the coordinate value input device 5 (step 61). Then, from the coordinate values input in step 61, the matrix (Step 62). In this example, if the rotation angle of the workpiece coordinate system with respect to the machine coordinate system is θ, the matrix Is as follows.

Next, in step 63, the command values V _XD and V _YD are input from the A / D converters 8a and 8b. Then, in step 200, the first clamp switch 100 and the second clamp switch 101
Read the signal from. When the first signal is output from the first clamp switch 100, the coefficient C _{Y is set} to 0 (step 20
If the first signal is not output, C _{Y is set} to 1 (steps 201, 203). Also, the second clamp switch 10
When the 1st to 2nd signals are output, the coefficient C _{X is set} to 0 (steps 204 and 205), and when the 2nd signal is not output, the coefficients are set.
Set C _X to 1 (steps 204 and 206). Then, the input command values V _XD and V _YD are multiplied by the coefficients C _X and C _Y, and then the matrix obtained earlier is used. _Are converted into command values V _xD and V _yD in the machine coordinate system using (step 64). That is, Is.

Then, the obtained command values V _xD and V _yD are output to the D / A converters 9a and 9b (step 65). After that, step 63, 200-2
06, 64 and 65 are executed continuously.

In the above embodiment, when measuring the workpiece two-dimensionally,
By calculating the rotation angle θ of the work coordinate system with respect to the machine coordinate system by using the coordinate values from the coordinate value input device without aligning the work coordinate system set on the work and the machine coordinate system of the stage in parallel, After that, the rotation angle θ is used to determine the matrix of velocity command values V _X and V _Y in the coordinate axis direction of the machine coordinate system of the joystick 7. Has the advantage that the stage rotation can be controlled by the velocity command values V _x and V _{y in} the coordinate axis direction of the work coordinate system.

In addition, depending on the content of the measurement, it may be desirable to make the stage movable only in one coordinate axis direction of the workpiece coordinate system set on the workpiece and prohibit movement of the stage in the other coordinate axis direction. Even in such a case, the first clamp switch 100 and the second clamp switch 101 are provided so as to correspond to the coordinate axes of the workpiece coordinate system. Therefore, turn on either the clamp switch 100 or 101. Thus, by ignoring the speed command value from the joystick in the corresponding coordinate axis direction and considering the speed command value in that direction as zero, the movement of the coordinate axis set on the workpiece in the arbitrarily selected direction can be performed. Can be banned.

FIG. 3 is a block diagram of the second embodiment of the present invention. Second
In the embodiment, the present invention is applied to a coordinate measuring machine having an X axis, a Y axis and a Z axis. In FIG. 3, those having the same functions as those in FIG. 1 are designated by the same reference numerals.

The X-axis encoder 1, the Y-axis encoder 2 and the Z-axis encoder 30 are mechanical coordinate system X, Y, which are coordinate values corresponding to the positions of the contacts of the probe 3'in the coordinate measuring machine.
A coordinate signal corresponding to the Z coordinate value is output. Probe 3 '
Outputs a contact signal when the contactor contacts the work. The switch circuit 4 receives coordinate signals from the X-axis encoder 1, the Y-axis encoder 2, and the Z-axis encoder 30 when a contact signal is input from the probe 3 ', and outputs the coordinate signals to the microcomputer.
Enter 60. A three-dimensional coordinate value input device 50 is formed by the above X-axis encoder 1, Y-axis encoder 2, Z-axis encoder 30, probe 3 ', and switch circuit 4. The microcomputer 60 calculates a coordinate conversion matrix from the input coordinate signal.

The joystick 71 has an operation lever (not shown), and the command value V _X = √ of the _X -axis, the Y-axis, and the Z-axis according to the inclination direction φ of the operation lever, the inclination angle Ψ, and the rotation angle γ of the rotary knob at the tip.
It outputs (Ψ) · cosφ, V _Y = V (Ψ) · sin φ, V _Z = V (γ). A / D converters 8a, 8b, 8c are command values V _X , V _Y , V
Each _Z is converted to analog / digital and digitized command value
Outputs V _XD , V _YD , and V _ZD . The micro computer 60 uses the coordinate conversion matrix that has previously obtained the digital command values V _XD , V _YD and V _ZD to determine the command values V _xD , V _yD and V _{zD of the} machine coordinate system.
Converted to and output. In addition, the first clamp switch 100 and the second clamp switch 1 are provided on the microcomputer 60.
01 and the third clamp switch 102 are connected. First
When the clamp switch 100 is turned on, the first signal is output, the microcomputer 60 having input the first signal ignores the command value V _YD , and when the second clamp switch 101 is turned on, the second signal is output and the second signal is output. The input microcomputer 60 ignores the command value V _XD . Further, when the third clamp switch 102 is turned on, the third signal is output and the third signal is output.
The microcomputer 60 which has input the signal ignores the command value V _ZD .

The command values V _xD , V _yD , V _zD are input to the D / A converters 9a, 9b, 9c and converted into analog command values V _x , V _y , V _z . The analog command values V _x , V _y and V _z are motor drive circuits 10a, 10b and 10 respectively.
Entered in c. The motor drive circuits 10a, 10b, 10c are driven by an X-axis motor 11a that drives the probe 3'in the X direction, a Y-axis motor 11b that drives in the Y direction, and a Z-axis motor 11c that drives in the Z direction.

Since the X-axis motor 11a, the Y-axis motor 11b, and the Z-axis motor 11c cooperate to move the probe 3'based on the work coordinate system, the joystick 71 is eventually changed from the drive unit according to the machine coordinate system to the coordinate value input unit. This means that the drive device has been converted according to the workpiece coordinate system obtained by 50.

Next, the operation of the microcomputer 60 will be described in detail with reference to the flow chart of FIG.

As shown in FIG. 4, the microcomputer 60 inputs the coordinate values for matrix determination by the coordinate value input device 50 (step 66). Then, from the coordinate values input in step 66, the matrix (Step 67). This matrix Is determined as follows. A coordinate axis that should correspond to the X axis and the Y axis determined by the joystick 71 is set on a certain plane (a surface on the work), and the direction perpendicular to this plane is made to correspond to the Z axis determined by the joystick 71. At this time, first, the coordinate values of three points that are not on the same straight line on the target plane (a certain surface on the work) and the coordinate values of two points on the axis that should be the x-axis on this plane are the coordinates. When input from the value input device 50 (step 66), the normal vector VI ₃ of this plane is obtained from the coordinate values of the former, and the spatial direction vector VI ₁ of this straight line is obtained from the coordinate values of the latter,
Further, the outer product VI ₂ (= VI ₃ × VI ₁ ) of the vectors VI ₁ and VI ₃ is obtained. Where VI ₁ , VI ₂ and VI ₃ are unit vectors When, the coordinate transformation matrix Given in step 67.

Next, in step 68, the command values V _XD , V _YD and V _ZD are input from the A / D converters 8a, 8b and 8c. And step 2
At 07, the signals from the first clamp switch 100, the second clamp switch 101, and the third clamp switch 102 are read. When the first signal is output from the first clamp switch 100, the coefficient C _{Y is set} to 0 (steps 208 and 209), and when the first signal is not output and C _{Y is set} to 1 (steps 208 and 21).
0). Further, when the second signal is output from the second clamp switch 101, the coefficient C _{X is set} to 0 (steps 211 and 212),
If the second signal is not output, C _{X is set} to 1 (step
211, 213). Furthermore, when the third signal is output from the third clamp switch 102, the coefficient C _{Z is set} to 0 (steps 214, 21
5) When the third signal is output, the coefficient C _{Z is set} to 1 (steps 214 and 216). And the input command value V _XD ,
V _YD and V _ZD are multiplied by the corresponding coefficients C _X , C _Y and C _{Z respectively,} and then the matrix obtained earlier is calculated. _Are converted into command values V _xD , V _yD , and V _zD in the machine coordinate system using (step 69).

Then, the obtained command values V _xD , V _yD , and V _zD are D / A converter 9
It is output to a, 9b and 9c (step 70). After that, step 6
8, 207 to 216, 69, 70 are continuously executed.

Therefore, with the above configuration, when measuring a three-dimensional workpiece, the X-axis and Y-axis of the Joystick 71 do not have to be aligned in parallel with the workpiece coordinate system set on the workpiece and the machine coordinate system of the coordinate measuring machine. , The speed command value in the Z-axis direction can be converted into coordinate rotation to correspond to the x-axis, y-axis, and z-axis of the work coordinate system set on the work.

Also in this case, the first clamp switch 100, the second clamp switch 101, and the third clamp switch 102 are provided corresponding to the coordinate axes of the work coordinate system.
Of the clamp switches 100, 101, 102, the speed command value in the coordinate axis direction corresponding to the switch that is turned on is ignored, and the speed command value in that direction is regarded as zero, so that the coordinate axis set on the workpiece can be set arbitrarily. Movement in the selected direction can be prohibited.

Furthermore, in the coordinate measuring machine, X- of the machine coordinate system X-Y-Z
Not only measurement based on a plane parallel to the Y plane, but YZ
In many cases, measurement based on a plane parallel to the plane or the Z-X plane is required. In the present embodiment, when measuring the side surface of the work in this way, the coordinate conversion matrix is made so that the direction perpendicular to the surface to be measured corresponds to the Z axis of the Joystick 71. Therefore, the movement of the probe 3'along the side surface of the workpiece is controlled by the X-axis and Y-axis operation of the operating lever in the Joystick 71, and the movement of the probe 3'perpendicular to the side surface is moved by the Z-axis of the operating lever in the Joystick 71. It can be done by axis operation.

In addition, sometimes a measurement is performed on a slope that is not parallel to any of the x-axis, y-axis, and z-axis once set on the work.
In this case, the X-axis, Y-axis, and Z-axis must be simultaneously operated by the operation lever of the joystick at all times to move the probe 3 along the slope or perpendicularly to the slope, which is extremely difficult. Is. In the present embodiment, in addition to the x-axis, y-axis, and z-axis once set on the workpiece, an axis perpendicular to the surface obtained by measuring the slope is made to correspond to the Z-axis of the joystick 7, and the other two of the joystick 7 are set. The advantage is that the three axes can correspond to orthogonal axes on a suitable slope to facilitate measurements on the slope.

Further, the work coordinate system is not limited to the rectangular coordinate system, and the clamp device of the present invention can be similarly provided even if the coordinate system is of another type. For example, if a cylindrical coordinate system (r, θ, h) is used as another type of coordinate system, V _X output from the joystick is associated with r, V _{Y is associated} with θ, and V _Z = h The computer 60 causes V _xD to move the probe 3 ′ in the r direction at the digital command value V _xD ,
The V _yD and V _zD signals may be determined.

Further, in the above embodiment, the calculation coefficient is selected as 0 or 1 according to the signal from the clamp switch.
The corresponding signal may be set to 0 on the input side of the microcomputers 6 and 60 by turning on the clamp switch. For example, by turning on the first clamp switch to forcibly drop the line in which V _Y is generated to the ground, the same effect as when the coefficient C _{Y is set} to 0 can be obtained.

In the above embodiments, the case where the joystick is used to issue the drive command is taken as an example, but it is also effective when the drive command is issued by the pulse of the track ball or the encoder attached to the manual knob. is there.

(Effects of the Invention) As described above, according to the present invention, the movement of the driven member in the second coordinate system can be easily and accurately realized, and the movement of the driven member in the arbitrarily selected direction can be performed. Since the movement of the driving member can be prevented, the efficiency of the measurement work can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram of the first embodiment of the present invention, FIG. 2 is a flow chart of the micro computer used in FIG. 1, FIG. 3 is a block diagram of the second embodiment of the present invention, and FIG. The flow chart of the micro-computer used in FIG. 3 shows the case where the coordinate axis XY of the machine coordinate system and the coordinate axis xy of the workpiece coordinate system on the workpiece are parallel. FIG. 6 is a plan view showing a case where the coordinate axis XY of the machine coordinate system and the coordinate axis xy of the work coordinate system have an angle θ. [Explanation of symbols of main parts] 1 ... X-axis encoder 2 ... Y-axis encoder 30 ... Z-axis encoder 3 '... Probe 4 ... Switch circuit 3 ... Coordinate capture switch 6,60 ... Microcomputer 7, 71 ・ ・ ・ Joystick 10a, 10b, 10c …… Motor drive circuit 11a …… X-axis motor 11b …… Y-axis motor 11c …… Z-axis motor 12 …… XY stage 100 …… 1st clamp switch 101… … Second clamp switch 102 …… Third clamp switch.

Front page continuation (72) Yuko Tsuchida Yuko Tsuchida 471 Nagaodai-cho, Totsuka-ku, Yokohama-shi, Kanagawa Japan Optical Industry Co., Ltd. Yokohama Works (56) Reference JP-A-53-48461 (JP, A) JP-A-57 -90105 (JP, A) JP-A-50-91346 (JP, A) JP-A-54-10765 (JP, A) JP-A-57-132015 (JP, A)

Claims (1)

[Claims] 1. A drive means for driving a driven member, and a drive command means for giving a drive command to the drive means based on a drive signal for driving the driven member along a coordinate axis of a first coordinate system. The drive command means converts the drive signal from the first coordinate system to a second coordinate system, and the driven member is moved to the second coordinate system.
Of the drive command to the drive means so as to move along the coordinate axis of the coordinate system of the second coordinate system, and block the movement of the driven member in the arbitrarily selected direction on the coordinate axis of the second coordinate system. A drive device based on a work coordinate system having means.