JP3939983B2 - Measuring method of movement / attitude control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a measurement method of a movement / posture control apparatus that controls a relative position and a relative posture between an object holding unit that holds a work target and an execution body holding unit that holds a work execution body.
[0002]
[Prior art]
Conventionally, as a polishing method of a workpiece such as a mold for molding an optical element, a method of reciprocating the polishing tool while pressing a small-diameter polishing tool against a processing surface of the workpiece with a constant force is used. ing. According to such a polishing method, the polishing depth can be adjusted by changing the moving speed of the polishing tool, the processing accuracy of the processing surface can be improved, and the waviness on the processing surface can be removed. it can.
[0003]
In such a polishing method, the removal depth at the processing point can be controlled more accurately by controlling the posture so that the normal line at the processing point on the processing surface and the load direction of polishing always match. Become. For this reason, such normal posture control is used for an optical element that requires high accuracy. As a processing method for controlling the normal posture, there are, for example, a cutting method and a grinding method in addition to the polishing method. FIG. 16 shows a polishing apparatus as a conventional example of a processing apparatus that performs such normal posture control.
[0004]
As shown in FIG. 16, the polishing apparatus 1 is driven and linearly driven in the X axis direction among the X axis, the Y axis, the Z axis, the A axis parallel to the X axis, and the B axis parallel to the Y axis. An X slide stage 2 that moves, a Y slide stage 3 that is driven and linearly moves in the Y-axis direction, a Z arm 4 that is an execution body holder and is driven and linearly moves in the Z-axis direction, and an A-axis that is driven and driven It has an A tilt stage 5 that rotates around (a direction) and a B tilt stage 6 that is driven and rotates around the B axis (b direction). By driving these stages 2, 3, 5, 6, linear movement in the X-axis and Y-axis directions of the work table 7, which is a work holding unit formed on the A tilt stage 5, and the a direction , B can be rotated, and by driving the Z arm 4, the polishing spindle 8 attached to the tip of the Z arm 4 can be linearly moved in the Z axis direction. The relative movement and relative posture between the work table 7 and the Z arm 4 are controlled. Each of these stages 2, 3, 5, 6 and the Z arm 4 can be NC (numerically controlled).
[0005]
In addition, a polishing tool 9 is provided on the polishing spindle 8 so as to be rotationally driven around the axis of the polishing spindle 8. The polishing spindle 8 and the polishing tool 9 constitute a work execution body.
[0006]
At this time, in the polishing apparatus 1, the Z-axis direction is a load control direction for controlling the pressing force of the polishing tool 9, and therefore the directions for positioning control according to the NC command are the X-axis direction, the Y-axis direction, the a direction, and b Often, there are four directions.
[0007]
Each stage 2, 3, 5 and 6 is driven in each direction by such linear motion and rotational motion by simultaneous control, and the tip of the polishing tool 9 or the surface of the workpiece 10 operates according to a desired locus. It is difficult to accurately measure whether or not, and several methods have been devised.
[0008]
As the simplest method, there is a method in which the current position in the moving or rotating direction of each stage 2, 3, 5, 6 is sampled and recorded at high speed, and the deviation from the command value is measured. In this method, the measurement object does not include errors in the positional relationship of each axis such as the parallelism between the X axis and the A axis and the orthogonality between the A axis and the Y axis, and posture errors such as pitching, yawing, and rolling. Does not exactly match the actual operation. In order to make them coincide, it is necessary to accurately grasp the positional relationship between each axis and the posture error. For example, in order to accurately grasp the positional relationship between the A-axis and the B-axis that are rotation axes. Therefore, it is necessary to use an expensive measuring instrument or a master gauge, which increases the cost.
[0009]
As another method, as shown in FIG. 17, the tool chuck 11 and the work chuck 12 are connected by a rod-shaped length measuring device 13 that can be expanded and contracted, the amount of expansion / contraction of this length measuring device 13 is detected, and the detected expansion / contraction is detected. There is a method for measuring the operation of the apparatus based on the quantity. Specifically, both ends of the length measuring device 13 are connected to the rotary bearings 14 and 15, the rotary bearing 14 is held by the tool check, and the rotary bearing 15 is held by the work chuck 12. In this state, the tool chuck 11 is moved along an arc locus centering on the rotary bearing 15. The roundness of the motion trajectory is evaluated by detecting the amount of expansion / contraction of the length measuring device 13 synchronized with the motion.
[0010]
However, such a method has a problem that the length measuring device 13 is expensive. In addition, since an accurate measurement cannot be performed when a stretching force is applied beyond the response speed of the length measuring device 13, it is necessary to reduce the feed rate for measurement when a high feed rate is used as an actual processing condition. There is. For this reason, there exists a problem that the operation | movement in actual processing conditions cannot be measured.
[0011]
[Problems to be solved by the invention]
As a method for simply measuring the operation of the processing apparatus or the moving stage and evaluating the positioning accuracy without using the length measuring device 13, for example, an XY slide stage for a stepper is disclosed in JP-A-7-325623. There is a method of acquiring an actual positioning error amount, storing it in a storage device, and performing positioning control using this as a correction amount. According to this method, the positioning error can be easily evaluated as long as the accuracy of the pattern to be referred to can be ensured, but it cannot be applied to the simultaneous control including the rotational motion.
[0012]
On the other hand, in the polishing apparatus 1 and the like for optical elements, a technique for creating a shape by controlling the residence time of the polishing tool 9 is widely used. Here, the residence time is the reciprocal of the feed rate, and the residence time control is the feed rate control itself. In such applications, it is also important to ensure the processing accuracy to confirm the actual feed speed on the processing surface of the workpiece 10, and it is difficult to easily measure with the conventional method.
[0013]
An object of the present invention is to provide a method for measuring an operation by control of a movement / attitude control device with high accuracy without using an expensive measurement device.
[0014]
[Means for Solving the Problems]
According to the first aspect of the present invention, the object holding unit and the execution body holding unit are controlled while controlling the relative posture between the object holding unit that holds the work object and the execution body holding unit that holds the work execution body. In the measurement method of the movement / posture control apparatus for controlling relative movement, the object holding unit and the object holding unit are arranged so that an angle between a curved surface of a reference object set in the object holding unit and the execution body holding unit is constant. A control process for controlling relative movement between the object holding unit and the execution body holding unit so that the execution body holding unit follows the curved surface of the reference object while controlling a relative posture with the execution body holding unit. And during the control process, a detection process of detecting a pattern that the curved surface of the reference object has a known interval by a sensor that moves relative to the object holding unit together with the execution body holding unit, including.
[0015]
Therefore, the curved surface of the reference object is controlled while controlling the relative posture between the object holding unit and the execution body holding unit so that the angle between the curved surface of the reference object set on the object holding unit and the execution body holding unit is constant. Data for obtaining the relative movement distance and relative speed between the object holding unit and the execution body holding unit by controlling the relative movement between the object holding unit and the execution body holding unit so that the execution body holding unit follows Is obtained.
[0016]
According to a second aspect of the present invention, in the measurement method of the movement / attitude control device according to the first aspect, the relative movement between the object holding unit and the execution body holding unit based on the pattern detected by the detection process. It includes a relative movement distance calculation process for obtaining a distance.
[0017]
Therefore, the curved surface of the reference object is controlled while controlling the relative posture between the object holding unit and the execution body holding unit so that the angle between the curved surface of the reference object set on the object holding unit and the execution body holding unit is constant. The relative movement distance between the object holding unit and the execution body holding unit can be obtained by controlling the relative movement between the object holding unit and the execution body holding unit so that the execution body holding unit is aligned with the execution body holding unit.
[0018]
According to a third aspect of the present invention, in the measurement method of the movement / attitude control device according to the first aspect, the object holding is performed based on the pattern detected by the detection process and a detection time interval of the pattern in the detection process. A relative speed calculation process for obtaining a relative speed between the execution unit and the execution body holding unit.
[0019]
Therefore, the curved surface of the reference object is controlled while controlling the relative posture between the object holding unit and the execution body holding unit so that the angle between the curved surface of the reference object set on the object holding unit and the execution body holding unit is constant. The relative speed between the object holding unit and the execution body holding unit can be obtained by controlling the relative movement between the object holding unit and the execution body holding unit so that the execution body holding unit follows the execution body holding unit.
[0020]
According to a fourth aspect of the present invention, in the measurement method of the movement / posture control apparatus according to the first, second, or third aspect, the pattern is formed on a flexible sheet that is attached to the curved surface of the reference object. ing.
[0021]
Therefore, since the sheet has flexibility, the pattern can be easily formed at an accurate position by making the sheet flat. Further, since the sheet has flexibility, it is possible to replace the sheet with a plurality of reference objects having different radii of curvature, for example.
[0022]
According to a fifth aspect of the present invention, in the measurement method of the movement / posture control apparatus according to the first, second, or third aspect, the pattern is formed on a surface of the curved surface of the reference object.
[0023]
Therefore, since the pattern is formed on the surface of the reference object, there is no influence of the pattern position error due to unevenness of the sheet thickness or uneven deformation considered when using the sheet, and it is set in the object holding part. The execution body holder is placed along the curved surface of the reference object while controlling the relative posture between the object holder and the execution body holder so that the angle between the curved surface of the reference object and the execution body holder is constant. When the relative movement distance or relative speed between the object holding unit and the execution body holding unit by controlling the relative movement between the object holding unit and the execution body holding unit, or when data for obtaining them is used as a sheet Compared to stable and highly accurate.
[0024]
According to a sixth aspect of the present invention, in the measurement method of the movement / attitude control device according to the first, second, third, fourth or fifth aspect, the sensor includes an image incorporating a non-contact displacement measuring sensor or a CCD light receiving element. It is an acquisition device.
[0025]
Therefore, compared with the case where a contact-type sensor is used as the sensor, the scanning speed on the detection surface can be increased, and the measurement can be performed at the feed speed used in actual processing. In the case of an image acquisition device, image processing can be performed by capturing a pattern as an image, and a resolution higher than the pattern pitch can be easily obtained.
[0026]
A seventh aspect of the present invention is the measuring method of the movement / posture control apparatus according to the first, second, third, fourth or fifth aspect, wherein the pattern is formed by a protrusion, a recess, or a protrusion and a recess. Yes.
[0027]
Therefore, an image acquisition device, a displacement measurement sensor, or the like can be applied as the sensor. Furthermore, when a sheet is used, a pattern can be formed at high speed by press molding or the like, and the sheet can be manufactured at low cost.
[0028]
Here, in the measurement method of the movement / attitude control device according to claim 7, the cross-sectional shape of the pattern may include any one of a circular shape, a rectangular shape, or a V shape. (Claim 8).
[0029]
According to a ninth aspect of the present invention, the object holding unit and the execution body holding unit are controlled while controlling a relative posture between the object holding unit that holds the work object and the execution body holding unit that holds the work execution body. In the measurement method of the movement / posture control apparatus for controlling relative movement, the object holding unit and the object holding unit are arranged so that an angle between a curved surface of a reference object set in the object holding unit and the execution body holding unit is constant. A control process for controlling relative movement between the object holding unit and the execution body holding unit so that the execution body holding unit follows the curved surface of the reference object while controlling a relative posture with the execution body holding unit. And, during the control process, forming a pattern on the curved surface of the reference object at a predetermined time interval by pattern forming means that moves relative to the object holding part together with the execution body holding part, and On the curved surface of the reference object Comprising a detection step of detecting made the said pattern.
[0030]
Therefore, the curved surface of the reference object is controlled while controlling the relative posture between the object holding unit and the execution body holding unit so that the angle between the curved surface of the reference object set on the object holding unit and the execution body holding unit is constant. Data for obtaining the relative movement distance and relative speed between the object holding unit and the execution body holding unit by controlling the relative movement between the object holding unit and the execution body holding unit so that the execution body holding unit follows Is obtained.
[0031]
A tenth aspect of the present invention is the measuring method of the movement / attitude control device according to the ninth aspect, wherein the pattern is formed on a flexible sheet attached to the curved surface of the reference object, and the detection process. Detects the pattern formed on the sheet that has been replaced by a flat stage from the curved surface of the reference object after the forming process.
[0032]
Therefore, for example, a pattern can be detected by a coordinate inspection machine such as a tool microscope, an image acquisition device, or the like, and fewer tools are required for carrying out this method.
[0033]
According to an eleventh aspect of the present invention, in the measurement method of the movement / attitude control device according to the ninth aspect, the pattern is formed on a surface of the curved surface of the reference object.
[0034]
Therefore, since the pattern is formed on the surface of the reference object, there is no influence of the pattern position error due to the sheet thickness unevenness or non-uniform deformation considered when using the sheet, and it is set in the object holding unit. Control the relative posture between the target object holding part and the execution object holding part so that the angle between the curved surface of the reference object and the execution object holding part is constant, and keep the execution object holding part along the curved surface of the reference object Compared to the case where the relative movement distance and relative speed between the object holding unit and the execution body holding unit by controlling the relative movement between the object holding unit and the execution body holding unit or the data for obtaining them is a sheet. Stable and highly accurate.
[0035]
According to a twelfth aspect of the present invention, in the measurement method of the movement / posture control apparatus according to the ninth, tenth, or eleventh aspect, the pattern forming means is an ink jet printer head or a laser marker.
[0036]
Therefore, by forming a pattern on a sheet with an inkjet printer head or a laser marker, it is possible to form a pattern from a soft resin material to a hard brittle material such as glass or ceramics. The constraint on becomes smaller.
[0037]
A thirteenth aspect of the present invention is the measurement method of the movement / posture control apparatus according to any one of the first to twelfth aspects, wherein the reference object is formed in a spherical shape or a cylindrical shape.
[0038]
Accordingly, a spherical shape or a cylindrical shape can be easily obtained with a higher shape accuracy than a shape having a non-circular cross section, and the accuracy evaluation is also easy. It can be realized at low cost.
[0039]
A fourteenth aspect of the present invention is the measuring method of the movement / posture control apparatus according to the fourth or tenth aspect, wherein the sheet is formed mainly of a resin material.
[0040]
Therefore, since the sheet formed of the resin material has a sufficient elastic range and its returnability, even a curved surface with a small radius of curvature can follow the curved surface, and when removed from the curved surface, the sheet is flat. It is possible to return to the state. Further, since the sheet is formed of a resin material and is soft, there is little risk of damaging the reference object even if the reference object is formed of a soft metal such as aluminum (Al).
[0041]
DETAILED DESCRIPTION OF THE INVENTION
[First embodiment]
A first embodiment of the present invention will be described with reference to FIGS. 1 to 4 and FIG. The present embodiment is an example of application to a measurement method of a polishing apparatus 1 that is a movement / posture control apparatus. This polishing apparatus 1 uses a concave cylindrical surface that is a curved surface as an example of a workpiece that is a work target. The concave cylindrical surface of the workpiece to be processed is polished. In addition, the same part as the part demonstrated in FIG. 16 is shown with the same code | symbol, and description is also abbreviate | omitted.
[0042]
As shown in FIG. 16, the polishing apparatus 1 includes an X slide stage 2, a Y slide stage 3, a Z arm 4 that is an execution body holding unit, an A tilt stage 5, and a B tilt stage 6. By driving these stages, it is possible to linearly move the work table 7, which is a work holding unit formed on the A tilt stage 5, in the X-axis and Y-axis directions and to rotate in the a- and b-directions. In addition, by driving the Z arm 4, the polishing spindle 8 attached to the tip of the Z arm 4 can be linearly moved in the Z-axis direction, whereby the work table 7 and the Z arm 4 are The relative movement and the relative posture of each are controlled. Each of these stages 2, 3, 5, 6 and the Z arm 4 can be NC (numerically controlled).
[0043]
A polishing tool 9 is provided on the polishing spindle 8. The polishing spindle 8 and the polishing tool 9 constitute a work execution body.
[0044]
The polishing apparatus 1 reciprocally moves the polishing tool 9 while pressing the rotationally driven polishing tool 9 against the processing surface of the workpiece 10 fixed to the work table 7 with a constant force. To polish. Specifically, in the present embodiment, the workpiece 10 is fixed to the work table 7 so that the cylindrical axis of the workpiece 10 is parallel to the X axis, and the polishing tool 9 is driven to rotate on the workpiece 10. While pressing with a constant load, the work table 7 is driven in the Y-axis positive (+) direction, moved slightly in the X-axis positive (+) direction at the end of the machining surface, and then driven in the Y-axis negative (-) direction. . In this way, the workpiece 10 is polished.
[0045]
During such a polishing operation of the polishing apparatus 1, each part is controlled so that the normal line at the processing point on the processing surface always matches the polishing load direction. Here, the normal posture of the machining point is maintained by rotationally driving the A tilt stage 5 and the B tilt stage 6. In the present embodiment, since the processing surface of the workpiece 10 is a concave cylindrical surface, and the workpiece 10 is fixed to the work table 7 so that the cylinder axis of the workpiece 10 is parallel to the X axis. The B tilt stage 6 is in a fixed state, and the normal posture control accompanying the scanning of the processed surface of the workpiece 10 by the polishing tool 9 is performed by rotating the A tilt stage 5. At this time, simultaneous two-way control in the Y-axis direction and the a-direction, that is, simultaneous control of the Y slide stage 3 and the A tilt stage 5 is performed.
[0046]
Next, the positioning accuracy evaluation of the polishing tool 9 and the method for measuring the unevenness of the scanning speed of the polishing tool 9 in the simultaneous two-way control of the Y direction and the a direction will be described with reference to FIGS. FIG. 1 is a perspective view showing a measurement form of the polishing apparatus 1, FIG. 2 is a front view showing a cylindrical test piece on which a sheet is attached, and FIG. 3 is a front view showing a state in which a dot pattern is formed on the sheet.
[0047]
First, as shown in FIGS. 1 and 2, a cylindrical test piece 22, which is a reference object in which a sheet 21 is attached to a curved surface, is set on the work table 7 via a V-shaped block 23. At this time, the columnar test piece 22 is arranged so that the columnar axis direction is parallel to the X-axis direction.
[0048]
Here, the sheet 21 is a transparent PET sheet having a thickness of 0.3 mm having flexibility, and a reflection-increasing film 21a (see FIG. 3) that reflects white light with high efficiency is formed on the back surface. Yes. On the sheet 21, a pattern P of points 25 by laser light is formed at regular intervals by a laser marker 24 (see FIG. 3) which is a pattern forming means. In the present embodiment, the diameter of the points 25 is set to 0.1 mm, the interval between the points 25 is set to 0.5 mm, and the pattern P of the points 25 is formed in a matrix.
[0049]
Here, a method of forming the pattern P of the points 25 on the sheet 21 will be described. First, as shown in FIG. 2, the sheet 21 is attached to a precision positioning stage 26 that is a movable plane. Thereafter, the laser beam is irradiated to the sheet 21 by the laser marker 24 to carbonize the sheet 21 to form a pattern P of points 25. At this time, the formed point 25 is a black color. The pattern forming means is not limited to the laser marker 24. For example, the ink may be ejected onto the sheet 21 using an ink jet printer head to form the pattern P of the points 25. As another example, a laser printer may be used for forming the pattern P on the sheet 21.
[0050]
The cylindrical test piece 22 has a cylindrical shape finished with high accuracy in order to evaluate the positioning accuracy of the polishing tool 9 and the scanning speed unevenness of the polishing tool 9 with high accuracy. Specifically, in the present embodiment, those having a roundness of 1 μm or less are employed. The curvature radius Rw of the cylindrical test piece 22 is 25.005 mm. Here, when measuring the operation of the polishing apparatus 1 in order to process the concave cylindrical workpiece 10 as the workpiece 10 as in the present embodiment, the reference workpiece is also made to the workpiece 10 as much as possible. Although it is more preferable to use a concave cylindrical shape that is a close shape, as a reference object having a high roundness, the cylindrical shape is easier to obtain. On the other hand, different reference shapes are used.
[0051]
As shown in FIG. 1, a CCD camera 27 as a sensor is attached to the polishing spindle 8 or the Z arm 4 at or near the polishing tool 9 attachment position (note that the polishing spindle 8 and the Z arm 4 are omitted in FIG. 1). ). As a result, the CCD camera 27 moves relative to the work table 7 together with the Z arm 4. Then, each stage 2, 3, 5, 6 is driven and positioned so that the CCD camera 27 can detect the sheet 21 and the vertex of the cylindrical test piece 22 coincides with the optical axis of the CCD camera 27. adjust. In this state, the normal line on the surface of the cylindrical test piece 22 on which the sheet 21 serving as a detection surface by the CCD camera 27 is attached coincides with the optical axis of the CCD camera 27. Here, the CCD camera 27 incorporates a CCD light receiving element and functions as an image acquisition device.
[0052]
Next, control to be measured is executed, and detection of the sheet 21 by the CCD camera 27 is executed. In the present embodiment, the cylindrical test is performed while controlling the relative posture between the work table 7 and the Z arm 4 so that the angle between the curved surface of the cylindrical test piece 22 set on the work table 7 and the Z arm 4 is constant. The relative movement of the work table 7 and the Z arm 4 is controlled so that the Z arm 4 is along the curved surface of the piece 22. Specifically, simultaneous control in the Y-axis direction and the a-direction is performed, and the optical axis of the CCD camera 27 that detects the sheet 21 attached to the cylindrical test piece 22 is regarded as a contact point of the polishing tool 9, and the polishing tool Reciprocating motion in the Y direction is performed while maintaining the normal posture similar to the scanning locus of 9.
[0053]
Here, in this embodiment, since the scanning width of the polishing tool 9 is set to ± 10 mm in the Y direction from the machining surface generatrix, the optical axis of the CCD camera 27 similarly moves ± 10 mm in the Y direction here. Giving a scan. At this time, the detection point on the optical axis of the CCD camera 27 is caused to move up and down by 2 mm to 3 mm by the control operation in the Y direction and the a direction, but this has a margin in the focal depth of the CCD camera 27. It becomes possible to cope with it. As another method, the CCD camera 27 can be dealt with by providing an autofocus function.
[0054]
Here, FIG. 4 is a graph showing the change in the amount of light entering one pixel near the optical axis of the CCD camera 27 with time. The horizontal axis of the graph 28 indicates time, and the vertical axis of the graph 28 indicates the amount of light entering one pixel near the optical axis of the CCD camera 27. Since the point 25 formed by the laser beam is black as described above, the reflection of light is reduced, so that when the point 25 crosses the optical axis of the CCD camera 27, the amount of light incident on the CCD camera 27 is reduced. To do. Thereby, on the graph 28, the portion of the reflected light from the point 25 appears as a waveform trough.
[0055]
Next, the actual relative moving distance and relative speed between the work table 7 and the Z arm 4 are obtained based on the graph 28, that is, the pattern P detected by the CCD camera 27. Specifically, first, since the interval between the patterns P of the points 25 formed on the sheet 21 is known as 0.5 mm, the lower limit point of the light amount such as the time interval Ta and the time interval T1 is counted in the graph 28. Thus, the actual scanning distance La and scanning distance L1 of the CCD camera 27 on the surface of the sheet 21 which is the detection surface at the time intervals Ta and T1 are acquired. That is, the actual relative movement distance between the work table 7 and the Z arm 4 is acquired. Thereby, the positioning accuracy of the polishing tool 9 can be evaluated.
[0056]
Next, since the interval between the patterns P of the points 25 similarly formed on the sheet 21 is known to be 0.5 mm, the accurate CCD camera 27 can be obtained from this value and the time interval T1 between the lower limit points of the light quantity in the graph 28. The actual relative scanning speed can be calculated. Further, by calculating the scanning speed at another time interval T2 and comparing the scanning speeds at the time intervals T1 and T2, it is possible to easily detect the speed unevenness. Thereby, the polishing tool 9 can be evaluated for uneven scanning speed.
[0057]
The above-described calculation of the relative movement distance and the relative scanning speed may be performed by data processing by a computer that is a data processing device that has received the data of the pattern P detected by the CCD camera 27, or the pattern P detected by the CCD camera 27. These data may be output as a graph as shown in FIG. 4 by a recorder such as a pen plotter or a data storage oscilloscope, and calculated based on the output graph.
[0058]
Here, in the above-described data processing, the resolution of the scanning distance L is 0.5 mm from the interval of the pattern P of the point 25. However, the above-described data processing is performed on a plurality of pixels of the CCD camera 27 and the CCD camera 27 It is possible to easily obtain a resolution of 0.1 μm or less by adjusting the magnification of the optical system.
[0059]
As described above, the cylindrical test is performed while controlling the relative posture between the work table 7 and the Z arm 4 so that the angle between the curved surface of the cylindrical test piece 22 set on the work table 7 and the Z arm 4 is constant. By controlling the relative movement between the work table 7 and the Z arm 4 so that the Z arm 4 follows the curved surface of the piece 22, the actual relative movement distance and relative speed between the work table 7 and the Z arm 4 are obtained. Data is obtained. Thereby, the measurement of the polishing apparatus 1 in the control of the relative movement while controlling the relative posture, which has been difficult to measure accurately with the prior art, can be easily performed with high accuracy without using an expensive measuring apparatus. And based on these measurement results, evaluation of the polishing apparatus 1 in the control of relative movement while controlling the relative attitude can be easily performed with high accuracy without using an expensive measuring apparatus. Furthermore, since the pattern P formed on the sheet 21 is formed with sufficient positional accuracy and the cylindrical test piece 22 is formed with high accuracy, the measurement can be performed with high accuracy. it can. Further, since the actual relative movement distance and relative speed between the work table 7 and the Z arm 4 can be obtained in a state extremely close to the actual work, the NC data is corrected and each axis of the polishing apparatus 1 is obtained based on the obtained data. Can be accurately and easily performed, whereby high working accuracy by the polishing apparatus 1 can be realized.
[0060]
Further, since the sheet 21 has flexibility, the pattern P can be easily formed at an accurate pitch and an accurate position by placing the sheet 21 in a planar state. In addition, since the sheet 21 has flexibility, the sheet 21 can be used by being replaced with respect to a plurality of reference objects having different curvature radii. Therefore, the curvature radius close to the actual workpiece 10 can be obtained with one sheet 21. Measurement using a plurality of test pieces can be performed.
[0061]
Further, the pattern P can be formed at high speed by the laser marker 24 or the ink jet printer head, and the sheet 21 with the pattern P can be manufactured at low cost by forming the pattern P on the sheet 21 by the laser marker 24 or the ink jet printer head. Can do.
[0062]
Further, by forming the pattern P on the sheet 21 by using the laser marker 24 or an ink jet printer head, the pattern P can be formed from a soft resin material to a hard brittle material such as glass or ceramics. It is possible to reduce the restrictions in
[0063]
In addition, as a reference object, a cylindrical object has a higher shape accuracy than a curved surface having a non-circular cross section, and the accuracy evaluation is easy. The form can be realized easily and inexpensively.
[0064]
Further, since the sensor is the CCD camera 27 having a built-in CCD light receiving element, the scanning speed on the detection surface can be increased as compared with the case where a contact type sensor is used as the sensor, and it is used in actual processing. It can be measured at the feed rate. Further, by capturing the pattern P as an image by the CCD camera 27, image processing becomes possible, and a resolution equal to or higher than the pattern P pitch of the point 25 can be easily obtained.
[0065]
Further, since the sheet 21 made of a resin material has a sufficient elastic range and its returnability, even a curved surface with a small radius of curvature can follow the curved surface, and when removed from the curved surface, the sheet 21 is in a flat state. Can be restored. Further, since the sheet 21 is formed of a resin material and is soft, there is little risk of damaging the columnar test piece 22 even if the columnar test piece 22 is formed of a soft metal such as aluminum (Al).
[0066]
In the present embodiment, the cylindrical test piece 22 having a cylindrical shape is described as an example of the reference object. However, the reference object is not limited to this. Moreover, spherical shape is mentioned as what has high shape accuracy like a cylindrical shape and can be obtained easily, and its accuracy evaluation is easy.
[0067]
In the present embodiment, the polishing apparatus 1 has been described as an example of the movement / posture control apparatus. However, the present invention is not limited to this, and may be a processing apparatus such as a cutting apparatus or a grinding apparatus. . In addition to the processing device, the movement / posture control device controls the relative movement between the target object holding unit and the execution body holding unit while controlling the relative posture between the target object holding unit and the work execution body. Any shape measuring device may be used.
[0068]
In the present embodiment, the example in which the CCD camera 27 is mounted on the polishing spindle 8 or the Z arm 4 at or near the mounting position of the polishing tool 9 has been described. However, the present invention is not limited to this. What is necessary is just to move relatively with respect to the work table 7 with the arm 4.
[0069]
[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. 5 is a plan view showing a sheet 21 on which a line pattern P is formed by grooves, FIG. 6 shows a V-shaped groove, (a) is a plan view, (b) is a longitudinal front view, and FIG. 7 is a semicircular shape. (A) is a plan view, (b) is a longitudinal front view, FIG. 8 is a rectangular groove, (a) is a plan view, (b) is a longitudinal front view, and FIG. FIG. 10 is a plan view showing the formed sheet 21, FIG. 10 shows a cross-sectional shape of the recess, (a) is a longitudinal front view showing the recess of the semicircular cross-sectional shape, and (b) is a longitudinal front view showing the recess of the rectangular cross-sectional shape. 11 and 11 show the sheet 21 on which the pattern P is formed by the protrusions 33. FIG. 11A is a plan view and FIG. 11B is a longitudinal front view.
[0070]
This embodiment is basically the same as the first embodiment. The difference from the first embodiment is that the pattern P formed on the sheet 21 is not due to the point 25 but the pattern P due to the dents or protrusions 33 formed on the sheet 21, and as a sensor. Instead of the CCD camera 27, a microwave sensor (not shown) which is a non-contact displacement measuring sensor is used.
[0071]
A first example of the sheet 21 according to the present embodiment will be described with reference to FIGS. The sheet 21 is formed with a groove 31 as a recess as shown in FIG. The grooves 31 are formed in a matrix and a line pattern P is formed by the grooves 31. The cross-sectional shape of the groove 31 is, for example, a V-shaped cross section as shown in FIG. 6A, a semicircular cross section as shown in FIG. 6B, a rectangular cross section as shown in FIG. .
[0072]
Next, a second example of the sheet 21 will be described with reference to FIGS. As shown in FIG. 9, recesses 32 are arranged in a matrix on the sheet 21, and a pattern P is formed by the recesses 32. The shape of the dent 32 is a hemispherical shape having a semicircular cross section as shown in FIG. 10A, a cylindrical shape having a rectangular cross section as shown in FIG.
[0073]
Next, a third example of the sheet 21 will be described with reference to FIG. 11A and 11B, hemispherical projections 33 are arranged in a matrix, and a pattern P is formed by the projections 33.
[0074]
In this way, the microwave sensor detects the pattern P formed by the groove 31, the dent 32, and the protrusion 33 formed in the sheet 21. As a result, the present embodiment can obtain the same operation as the first embodiment.
[0075]
Furthermore, since the pattern P shown in the present embodiment is the groove 31, the dent 32, or the protrusion 33, the sheet 21 can be formed at a high speed by press molding or the like. Therefore, the sheet 21 can be manufactured at low cost. Can do.
[0076]
In the present embodiment, the V-shaped cross section, the semicircular cross section, the rectangular cross section, and the like have been described as examples of the cross-sectional shape of the groove 31, but in implementation, these V-shaped cross section, semicircular cross section, The grooves 31 may be formed by combining rectangular cross sections and the like.
[0077]
In the present embodiment, the example in which the pattern P is formed by the groove 31, the recess 32, and the protrusion 33 has been described. However, the present invention is not limited to this. For example, the pattern P is formed by combining the recess 32 and the protrusion 33. May be.
[0078]
[Third embodiment]
Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 12 is a perspective view showing a cylindrical test piece 22 in which a dot pattern P is formed in advance, and FIG. 13 is a perspective view showing a cylindrical test piece 22 in which a line pattern P is formed in advance. In addition, the same part as the part demonstrated in 1st Embodiment is shown with the same code | symbol, and description is also abbreviate | omitted (the following embodiment is also the same).
[0079]
This embodiment is basically the same as the first embodiment. The difference 25 from the first embodiment is that the cylindrical test piece 22 in which the pattern P is directly formed on the curved surface in advance is used without attaching the sheet 21 to the cylindrical test piece 22. Here, the pattern P formed on the cylinder is the same as the pattern P formed on the sheet 21 in the first and second embodiments. In this case, the CCD camera 27 is used in the case of the point pattern P, and the microwave sensor is used in the case of a protrusion or a dent.
[0080]
Thus, the CCD camera 27 and the microwave sensor detect the pattern 25 formed by the points 25, the protrusions 33, and the depressions formed on the cylindrical test piece 22. As a result, the present embodiment can obtain the same operation as the first embodiment.
[0081]
Here, in the present embodiment, an apparatus capable of forming an accurate pattern P on the cylindrical test piece 22 is required. On the other hand, the pattern P is directly formed on the cylindrical test piece 22, and the thickness unevenness of the sheet 21 is Since there is no influence of the error of the pattern P pitch due to the non-uniform deformation or the like, the polishing apparatus 1 can be measured with higher accuracy.
[0082]
[Fourth embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 14 is a side view showing a state of forming a pattern P on the concave cylindrical test piece, and FIG. 15 is a front view showing a state of detecting the pattern P formed on the sheet 21.
[0083]
The difference of the present embodiment from the first embodiment is that a concave cylindrical test piece 41 having a high precision is used as a reference object, and is attached to the curved surface of the concave cylindrical test piece 41. The pattern P is formed in the polishing apparatus 1 to which the pattern forming means is attached on the sheet 21 on which the pattern P such as dots is not formed, and the polishing apparatus 1 is measured based on the formed pattern P.
[0084]
Specifically, first, as shown in FIG. 14, the concave cylindrical test piece 41 is set on the work table 7. Further, instead of the CCD camera 27, a laser marker 24, which is a pattern forming means, is attached to the polishing spindle 8 or the Z arm 4 at or near the polishing tool 9 attachment position (Note that the polishing spindle 8 and the Z arm 4 are omitted in FIG. 14). ing).
[0085]
Next, a pattern P of dots is formed on the surface of the sheet 21 by the laser marker 24 at a predetermined time interval Tb while performing the control to be measured as in the first embodiment. An ink jet printer head may be used instead of the laser marker 24.
[0086]
Next, the sheet 21 on which the pattern P is formed is removed from the concave cylindrical test piece 41 and returned to the planar form along the planar precision positioning stage 26 as shown in FIG. In this state, the point pattern P is detected by the CCD camera 27 while moving the precision positioning stage 26 at a predetermined speed. The change in the amount of light entering one pixel near the optical axis of the CCD camera 27 with the passage of time at this time is the same as the graph 28 shown in FIG. 4 in the first embodiment.
[0087]
Next, the actual relative movement distance and relative speed between the work table 7 and the Z arm 4 are obtained based on the pattern P detected by the CCD camera 27. First, the relative movement distance will be described. Since the moving speed of the precision positioning stage 26 is known, the laser marker 24 on the surface of the sheet 21 that is the detection surface is obtained by multiplying this moving speed by the time interval Ta or the time interval T1 between the lower limit points of the light amount in the graph 28. The actual scanning distances La and L1 are acquired. That is, the actual relative movement distance between the work table 7 and the Z arm 4 is acquired. Thereby, the positioning accuracy of the polishing tool 9 can be evaluated.
[0088]
Next, the relative speed will be described. First, the time interval Tb when the pattern P is formed on the surface of the sheet 21 by the laser marker 24 is known, and the laser marker 24 scans the actual scanning distance L1 of the laser marker 24 at the time interval T1 in the graph 28. It took time to do. Thereby, the actual relative scanning speed of the laser marker 24 can be accurately calculated by dividing the scanning distance L1 by the time interval Tb. Further, by calculating the scanning speed at another time interval T2 and comparing the scanning speeds at the time intervals T1 and T2, it is possible to easily detect the speed unevenness. Thereby, the scanning speed unevenness of the polishing tool 9 can be evaluated.
[0089]
As described above, while controlling the relative posture between the work table 7 and the Z arm 4 so that the angle between the curved surface of the concave cylindrical test piece 41 set on the work table 7 and the Z arm 4 is constant, The actual relative movement distance or relative speed between the work table 7 and the Z arm 4 by controlling the relative movement between the work table 7 and the Z arm 4 so that the Z arm 4 follows the curved surface of the cylindrical test piece 41, or those The data for obtaining is obtained. Thereby, the measurement of the polishing apparatus 1 in the control of the relative movement while controlling the relative posture, which has been difficult to measure accurately with the prior art, can be easily performed with high accuracy without using an expensive measuring apparatus. And based on these measurement results, evaluation of the polishing apparatus 1 in the control of relative movement while controlling the relative attitude can be easily performed with high accuracy without using an expensive measuring apparatus. Furthermore, the pattern P formed on the sheet 21 is formed with sufficient positional accuracy, and the concave cylindrical test piece 41 is formed with high accuracy, so that the evaluation is performed with high accuracy. Can do. Further, since the actual relative movement distance and relative speed between the work table 7 and the Z arm 4 can be obtained in a state extremely close to the actual work, the NC data is corrected and each axis of the polishing apparatus 1 is obtained based on the obtained data. Can be accurately and easily performed, whereby high working accuracy by the polishing apparatus 1 can be realized.
[0090]
Further, since the pattern P formed on the sheet 21 that has been replaced by the precision positioning stage 26 from the curved surface of the concave cylindrical test piece 41 is detected, the pattern can be detected by the CCD camera 27, and this method is carried out. Therefore, the present method can be easily carried out.
[0091]
In the present embodiment, an example in which the concave cylindrical test piece 41 is used as a reference object has been described. However, the reference object is not limited to this.
[0092]
In the present embodiment, the pattern P is detected by the CCD camera 27. However, the pattern P may be detected by a coordinate inspection machine such as a tool microscope.
[0093]
[Fifth embodiment]
Next, although not particularly shown, a fifth embodiment of the present invention will be described.
[0094]
This embodiment is basically the same as the fourth embodiment. The difference 25 from the fourth embodiment is that the sheet P is not attached to the concave cylindrical test piece 41, and the pattern P is directly formed on the curved surface of the concave cylindrical test piece 41 by the laser marker 24 or the like. is there.
[0095]
After the pattern P is formed, the pattern P of the concave cylindrical test piece 41 is accurately detected by a measuring instrument, an inspection instrument (not shown) or the like.
[0096]
In this manner, the actual relative movement distance and relative speed between the work table 7 and the Z arm 4 are acquired based on the pattern P measured by the measuring instrument as in the fourth embodiment. As a result, the present embodiment can obtain the same operation as the fourth embodiment.
[0097]
Here, in the present embodiment, an apparatus for accurately detecting the pattern P formed on the concave cylindrical test piece 41 is required. On the other hand, the pattern P is directly formed on the concave cylindrical test piece 41 and the sheet 21 is formed. Therefore, it is possible to evaluate the polishing apparatus 1 with higher accuracy because there is no influence of an error of the pattern P pitch caused by unevenness of thickness or uneven deformation.
[0098]
In the present embodiment, an example in which the concave cylindrical test piece 41 is used as a reference object has been described, but the reference object is not limited to this. For example, when the cylindrical test piece 22 is used, a pattern P similar to the pattern P as shown in FIG. 12 is formed on the cylindrical test piece 22.
[0099]
【The invention's effect】
According to the first to fourteenth aspects of the present invention, the relative relationship between the object holding unit and the execution body holding unit is such that the angle between the curved surface of the reference object set in the object holding unit and the execution body holding unit is constant. While controlling the posture, the relative movement between the object holding unit and the execution body holding unit is controlled by controlling the relative movement between the object holding unit and the execution body holding unit so that the execution body holding unit follows the curved surface of the reference object. Since movement distance, relative speed, or data for obtaining them can be obtained, it is easy to measure the movement and attitude control device in the control of relative movement while controlling the relative attitude, which was difficult to measure accurately with the conventional technology. Can be done. Further, since the relative movement distance and relative speed between the object holding unit and the execution body holding unit can be obtained in a state very close to the actual action, the correction of the NC command and the movement / posture control device The alignment of each axis can be performed accurately and easily, and thereby high working accuracy by the movement / posture control device can be realized.
[0100]
In particular, according to the invention described in claim 4, since the sheet has flexibility, the pattern can be easily formed at an accurate position by bringing the sheet into a flat state. Further, since the sheet has flexibility, for example, the sheet can be used by being replaced with respect to a plurality of reference objects having different curvature radii. Thereby, it is possible to perform measurement using a plurality of reference objects having a radius of curvature close to that of an actual work target with one sheet.
[0101]
According to the fifth aspect of the present invention, since the pattern is formed on the surface of the reference object, there is no influence of an error in the pattern position due to unevenness of the sheet thickness or uneven deformation considered when using the sheet. The curved surface of the reference object is controlled while controlling the relative posture between the target object holding part and the execution object holding part so that the angle between the curved surface of the reference object set on the object holding part and the execution object holding part is constant. Relative movement distance and relative speed between the object holding unit and the execution body holding unit by controlling the relative movement between the object holding unit and the execution body holding unit so that the execution body holding unit is aligned. Data can be obtained stably and with high accuracy compared to the case of using a sheet.
[0102]
According to the sixth aspect of the present invention, since the sensor is a non-contact type displacement measuring sensor or an image acquisition device with a built-in CCD light receiving element, compared to the case where a contact type sensor is used as the sensor, The scanning speed can be increased, and measurement can be performed at a feed speed used in actual processing. In the case of an image acquisition device, image processing can be performed by capturing a pattern as an image, and resolution higher than the pattern pitch can be easily obtained.
[0103]
According to invention of Claim 7, an image acquisition apparatus, a displacement measuring sensor, etc. are applicable as a sensor. Furthermore, when a sheet is used, a pattern can be formed at high speed by press molding or the like, and the sheet can be manufactured at low cost.
[0104]
According to the invention described in claim 10, since the pattern can be detected by a coordinate inspection machine such as a tool microscope, an image acquisition device, or the like, and fewer tools are required for carrying out the method, the method Can be easily implemented.
[0105]
According to the invention of claim 11, since the pattern is formed on the surface of the reference object, there is no influence of an error of the pattern position due to unevenness of the sheet thickness or uneven deformation considered when using the sheet, Execute on the curved surface of the reference object while controlling the relative posture between the target object holding part and the execution object holding part so that the angle between the curved surface of the reference object set on the object holding part and the execution object holding part is constant. The relative movement distance and relative speed between the object holding unit and the execution body holding unit by controlling the relative movement between the object holding unit and the execution body holding unit so that the body holding unit is aligned, or data for obtaining them. Can be obtained stably and highly accurately as compared with the case of using a sheet.
[0106]
According to the twelfth aspect of the present invention, it is possible to form a pattern from a soft resin material to a hard brittle material such as glass or ceramics, and it is possible to reduce restrictions on the material surface of the reference body or the sheet.
[0107]
According to the thirteenth aspect of the present invention, it is possible to easily obtain a spherical shape or a cylindrical shape having a higher shape accuracy than a shape having a non-circular cross section, and the accuracy evaluation thereof is also easy. Therefore, this method can be realized easily and inexpensively.
[0108]
According to the invention described in claim 14, since the sheet formed of the resin material has a sufficient elastic region and its returnability, even a curved surface with a small radius of curvature can follow the curved surface. When it is removed from the curved surface, it can be returned to the flat state. Further, since the sheet is made of a resin material and is soft, the risk of damaging the reference object can be reduced even if the reference object is formed of a soft metal such as aluminum (Al).
[Brief description of the drawings]
FIG. 1 is a perspective view showing a measurement form of a polishing apparatus according to a first embodiment of the present invention.
FIG. 2 is a front view showing a cylindrical test piece to which a sheet is attached.
FIG. 3 is a front view showing a state in which a dot pattern is formed on a sheet.
FIG. 4 is a graph showing a change in the amount of light entering one pixel near the optical axis of a CCD camera over time.
FIG. 5 is a plan view showing a sheet on which a line pattern is formed by grooves according to the second embodiment of the present invention.
6A and 6B show a V-shaped groove, wherein FIG. 6A is a plan view and FIG. 6B is a longitudinal front view.
7 shows a semicircular groove, (a) is a plan view, and (b) is a longitudinal front view. FIG.
8A and 8B show a rectangular groove, where FIG. 8A is a plan view and FIG. 8B is a longitudinal front view.
FIG. 9 is a plan view showing a sheet on which a pattern is formed by dents.
FIG. 10 shows a sectional shape of a dent, (a) is a longitudinal front view showing a dent having a semicircular sectional shape, and (b) is a longitudinal front view showing a dent having a rectangular sectional shape.
11A and 11B show a sheet on which a pattern is formed by protrusions, where FIG. 11A is a plan view and FIG. 11B is a longitudinal front view.
FIG. 12 is a perspective view showing a cylindrical test piece on which a dot pattern is formed in advance according to the third embodiment of the present invention.
FIG. 13 is a perspective view showing a cylindrical test piece in which a line pattern is formed in advance.
FIG. 14 is a side view showing a state of pattern formation on a concave cylindrical test piece according to a fourth embodiment of the present invention.
FIG. 15 is a front view showing a state of detection of a pattern formed on a sheet.
FIG. 16 is a perspective view showing a conventional polishing apparatus.
FIG. 17 is a front view showing an evaluation state.
[Explanation of symbols]
1 Movement / Attitude Control Device
4 Execution body holding part (Z arm)
7 Object holding part (work table)
8 Work execution body (polishing spindle)
9 Work execution body (polishing tool)
10 Work object (workpiece)
22 Reference object (cylindrical test piece)
24 Pattern forming means, laser marker
26 stages (Precision positioning stage)
27 Sensor, image acquisition device (CCD camera)
31 dent (groove)
32 dent
33 Protrusions
41 Reference object (concave cylindrical test piece)
P pattern

Claims (14)

A movement / posture for controlling the relative movement between the object holding unit and the execution body holding unit while controlling the relative posture between the object holding unit holding the work object and the execution body holding unit holding the work execution body. In the measurement method of the control device,
While controlling the relative posture between the object holding unit and the execution body holding unit so that the angle between the curved surface of the reference object set on the object holding unit and the execution body holding unit is constant, the reference A control process for controlling relative movement between the object holding unit and the execution body holding unit so that the execution body holding unit is along the curved surface of an object;
A detection process of detecting a pattern that the curved surface of the reference object has a known interval during the control process using a sensor that moves relative to the object holding unit together with the execution body holding unit;
A measuring method of a movement / attitude control device characterized by comprising: 2. The movement / posture according to claim 1, further comprising a relative movement distance calculation step of obtaining a relative movement distance between the object holding unit and the execution body holding unit based on the pattern detected by the detection process. Control device measurement method. Including a relative speed calculation process for obtaining a relative speed between the object holding unit and the execution body holding unit based on the pattern detected by the detection process and a detection time interval of the pattern in the detection process. The measuring method of the movement / attitude control device according to claim 1 or 2. The measuring method of the movement / posture control apparatus according to claim 1, wherein the pattern is formed on a flexible sheet attached to the curved surface of the reference object. The measuring method of the movement / attitude control device according to claim 1, wherein the pattern is formed on a surface of the curved surface of the reference object. 6. The method of measuring a movement / attitude control device according to claim 1, wherein the sensor is a non-contact displacement measuring sensor or an image acquisition device incorporating a CCD light receiving element. 6. The measuring method of the movement / posture control apparatus according to claim 1, wherein the pattern is formed by a protrusion, a dent, or a protrusion and a dent. The measurement method of the movement / attitude control apparatus according to claim 7, wherein the cross-sectional shape of the pattern includes any one of a circular shape, a rectangular shape, or a V shape. A movement / posture for controlling the relative movement between the object holding unit and the execution body holding unit while controlling the relative posture between the object holding unit holding the work object and the execution body holding unit holding the work execution body. In the measurement method of the control device,
While controlling the relative posture between the object holding unit and the execution body holding unit so that the angle between the curved surface of the reference object set on the object holding unit and the execution body holding unit is constant, the reference A control process for controlling relative movement between the object holding unit and the execution body holding unit so that the execution body holding unit is along the curved surface of an object;
A forming process of forming a pattern on the curved surface of the reference object at predetermined time intervals by pattern forming means that moves relative to the object holding unit together with the execution body holding unit during the control process;
A detection process for detecting the pattern formed on the curved surface of the reference object;
A measuring method of a movement / attitude control device characterized by comprising: The pattern is formed on a flexible sheet attached to the curved surface of the reference object,
The movement / posture according to claim 9, wherein the detecting step detects the pattern formed on the sheet that is replaced with a flat stage from the curved surface of the reference object after the forming step. Control device measurement method. The measurement method of the movement / attitude control apparatus according to claim 9, wherein the pattern is formed on a surface of the curved surface of the reference object. 12. The measurement method of the movement / attitude control apparatus according to claim 9, wherein the pattern forming unit is an ink jet printer head or a laser marker. The measuring method of the movement / attitude control device according to claim 1, wherein the reference object is formed in a spherical shape or a cylindrical shape. The measuring method of the movement / attitude control device according to claim 4, wherein the sheet is formed mainly of a resin material.

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