JPH0238913A - Dimension inspecting method for work - Google Patents

Abstract

PURPOSE:To accurately measure the dimension of a work by inspecting the size of the work according to coordinate values corrected based upon a correcting value for eliminating a positioning error. CONSTITUTION:A driving device which drives a manipulator 26 and a driving device 28 is connected to a movement console panel 44, a numerical controller 46, and a dimension inspecting device 48 through a console panel 42. The dimension inspecting device 48 is connected to a display device 50 and a printer 52. This dimension inspecting device 48 corrects the coordinate values of an expected measurement start point and the coordinate values of an expected measurement carrying-out point as criteria according to the correcting value for eliminating the positioning error of the work and also inspects the dimension of the work according to the corrected coordinate values. The inspection result is outputted on a floppy disk 56 and a printer 52.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for inspecting dimensions of a workpiece, and particularly to a method for inspecting dimensions of a workpiece suitable for measuring the surface shape of a large structure.

[Conventional technology]

As a workpiece for a large structure, a welded water turbine runner 1 is known as shown in FIG. It consists of 4. Among these, each surface of the vane 2 is formed into an arbitrary shape, as shown in FIG. As a method for measuring the side shape of such a workpiece, there is 1, for example, JP-A-61-10
The one described in Publication No. 702 is known,
Even if a workpiece of a large structure such as vane 2 is set up using a special jig, as shown in Figure 9, there is no positioning between the position during bending and the set up position after bending. An error will occur. For this reason, there was a possibility that the profile shape of the vane 2 could not be followed by the conventional measurement method.

[Problem to be solved by the invention]

The above conventional technology does not take into consideration the fact that positioning errors occur when setting up the workpiece, and the positioning errors during setting up may reduce the accuracy of the side chamber, or the vane 2
There were cases where the so-called ruler could not follow the profile shape of the machine. Note that if the position of the reference point before bending the vane 2 matches the position of the reference point during setup after bending, the above-mentioned drawbacks can be solved, but if a large structure like the vane 2 It is difficult to change the setup many times.

An object of the present invention is to provide a workpiece dimension inspection method that can correct the positioning error and inspect the dimensions of the workpiece according to accurate positional information even if a positioning error occurs during workpiece setup.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention provides a measurement execution point group generated based on a measurement reference point in a measurement execution point group indicating each grid point when a work surface is divided into a plurality of regions. The standard coordinate values in the three-dimensional space and the shape information before setup regarding the inclination of the workpiece with respect to each axis in the three-dimensional space are generated in advance, and the offset value is added to the standard coordinate value of each measurement execution point. Generate the coordinate values in the three-dimensional space of the scheduled start point group based on the reference coordinate values, and measure the coordinate values in the three-dimensional space of the measurement reference point of the set-up workpiece and the scheduled measurement execution point of the workpiece end, respectively. Then, from this measured value, the deviation of the measurement reference point before and after setup is calculated, and shape information regarding the inclination of the workpiece with respect to each axis in three-dimensional space is generated, and the workpiece is calculated from this shape information and the shape information before setup. A first correction value for zeroing out the deviation of the measurement reference point and a second correction value for zeroing the workpiece setup deviation are calculated from each of the calculated values. Then, correct the coordinate values by adding each correction value to the coordinate values of each scheduled measurement execution point and each scheduled measurement start point, and then bring the probe into contact with the workpiece surface based on the corrected coordinate values of the scheduled measurement start point group. The workpiece is moved sequentially to the specified position, measures the coordinate value in three-dimensional space of each measurement execution point, and compares this measurement value with the corrected reference coordinate value of each measurement execution point to inspect the dimensions of the workpiece. This method uses a dimensional inspection method.

Furthermore, in addition to the above method, when the comparison value between the measured value and the corrected reference coordinate value deviates from the judgment reference value, the coordinate value of this measurement execution point is memorized, and based on this memorized coordinate value, an error is detected. This method employs a workpiece dimension inspection method that prints marks at the measurement execution points.

[Effect]

When the workpiece is set up, the coordinate values in the three-dimensional space of the measurement reference point of the workpiece and the scheduled measurement execution point of the end of the workpiece are measured. Then, from this measured value, the deviation of the measurement reference point before and after setup is calculated, and shape information regarding the inclination of the workpiece is generated, and the amount of setup deviation of the workpiece is calculated from this shape information and the shape information before setup. Then, a first correction value for making the deviation of the measurement reference point zero and a second correction value for making the workpiece setup deviation amount zero are determined, and each correction value is applied to each scheduled measurement point and each measurement. Modify the coordinate values in addition to the coordinate values of the scheduled execution start point. The probe is then moved along the workpiece surface based on the corrected coordinate values of the scheduled measurement start point group, and the point where the probe contacts the workpiece surface is defined as the measurement execution point, and the coordinate values of this point are measured. . This makes it possible to accurately measure the coordinate values of each measurement execution point. In other words, the reference coordinate value, which is the position information before setup, is corrected based on the coordinate values of the measurement reference point of the setup workpiece and the measurement execution point at the end of the workpiece, and the measuring stylus is adjusted according to the corrected reference coordinate value. Since it is made to move, even if a positioning error occurs during setup, this positioning error can be corrected.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1 to 6.

In FIGS. 2 and 3, a plurality of columns 12 are erected where the vanes 10 of a welded water turbine runner, which is a large structure, are set up, and a base 14.1G connecting the tops of each column 12 is shown. A rail 18 is installed. A cart 20 is mounted on each rail 18 so as to be movable along the X direction. A pair of rails 22 are installed on the upper part of the truck 2o, and a drive device 2 is installed on each rail 22.
4 is fixed so as to be movable along the Y direction.

A manipulator 26 having three orthogonal axes is fixed to approximately the center of the drive device 24 so as to be movable in the Z direction. At the lower end of the manipulator 26.

As shown in FIG. 4, an articulated, three-axis active part 28 is fixed, and the main body 3 of the measurement sensor 30 is attached to the drive part 28.
2 is fixed. A shaft-shaped measuring element 34 is fixed to the main body 32 so as to be extendable and retractable. This measuring head 3
4 has a sharp tip, and a marking head 38 containing a marking liquid 36 is removably attached to the measuring head 34. The manipulator 26 is movable along the first X-axis, the second Y-axis, and the third Z-axis by driving the drive device 24. It is possible to move within a driving range 40 shown by the broken line in FIG.

The drive unit 28 has a fourth pivot axis C that rotates around the Z axis, a fifth bending axis A that is on the pivot axis C and performs a bending operation with respect to the pivot axis C, It is located on the bending axis A and has a function as a sixth axis, the twisting axis U, which rotates about the center of the bending axis A.

Note that the fourth to sixth axes do not refer to pivot shafts that form the center of rotation, but to rotary arms. and manipulator 2
6 and the driving unit 28, the position and attitude of the measurement sensor 30 with respect to the vane 1o are determined. Further, the tip of the measuring stylus 34 is located at the center of rotation of the twisting axis U of the sixth axis, so that positional deviation does not occur due to the twisting operation of the twisting axis U.

The drive device 24 for driving the manipulator 26 and the drive unit 28 is connected to the movable operation panel 44 and the numerical control device 461 through the operation g142.

The dimension inspection device 48 includes a display device 50. The device 48 is connected to a printer 52, and a floppy disk 54 for storing reference data and the like and a floppy disk 56 for storing data on dimensional inspection results are attached to the device 48. This floppy disk 54 is configured to store various data generated by a large computer 58 via a terminal 60. This data includes: scheduled measurement points Q t indicating each grid point when the surface of the vane 10, which is a workpiece, is divided into a plurality of regions; each scheduled measurement point generated based on the measurement reference point in the J group; Q I
There is data on reference coordinate values of J in the three-dimensional space and data on pre-setup shape information regarding the inclination of the vane 10 with respect to each axis in the three-dimensional space. These data are generated based on the bending command values for the vane 10. Based on the reference data stored in the floppy disk 54, the dimension inspection device 48 starts measurement by adding an offset value d to the reference coordinate values of each scheduled measurement point QIJ, as shown in FIG. Coordinate values of the group of planned points PI3 in three-dimensional space are generated. The coordinate value data is then input to the numerical control device 46, and the drive device 24. The data is converted into numerical data for driving the manipulator 26 and the drive unit 28. The operation panel 42 controls the driving device 24 based on the numerical data and control program from the numerical control device 46.
A drive command for driving the manipulator 26 and the drive unit 28 is output. As a result, the drive unit W24, the drive unit 28
The manipulator 26 is driven, and the tip side of the probe 34 is controlled to be in a position normal to the measurement execution point Q I J and positioned at the measurement start point PiJ. After that, when the measuring stylus 34 moves toward the scheduled measurement execution point Q I J according to a command from the operation panel 42 and comes into contact with the surface of the vane 10, this point becomes the measurement execution point, and the coordinate values of the measurement execution point are measured. 6 and this data is subjected to operation f
f142, dimension inspection device 48 via numerical control device 46
The data is then transferred to the dimension inspection device 48 and compared with reference data. The data of the dimensional inspection results obtained by this comparison are stored in the floppy disk 56 and output to the printer 52.

Next, a method for inspecting the dimensions of the vane 10 will be explained based on the flowchart shown in FIG.

After the vane 10 is carried into the area surrounded by the struts 12 and the vane 10 is set up, the operation panel 42 is operated to give a drive command to the drive device 24.

The measurement sensor 30 is moved until the measuring element 34 comes into contact with the measurement reference point of the vane 10 (a point formed by a scribing line approximately at the center of the vane 10), and the coordinate values of the measurement reference point Po' are measured (step SL).

After that, the deviation between the coordinate value of the measurement reference value generated before setup and the coordinate value of the measurement reference point measured after setup is calculated (step S2). This deviation is.

As shown in FIG. 6, the XY plane of the vane 10.

Measurement reference point Po before setup on ZY plane and XZ plane
and the measurement reference point Po' after setup. Then, based on this deviation, it is determined whether or not there is a deviation in the measurement reference point (step S3), and if there is a deviation in the measurement reference point, a first correction value is set in order to make the deviation of the measurement reference point zero. is calculated (step S4), and the coordinate values of the seven groups of measurement execution points Q I are corrected based on the first correction value (step $5).

Next, the measurement sensor 30 is moved to the end P^' of the vane 1o by a command from the operation panel 42, and the measurement sensor 30 is moved to the end P^' of the vane 10.
Measure the coordinate values of ^' (step S6), input the shape data regarding the inclination of the vane 10 that was generated before setup (step S7), calculate the amount of setup deviation of the vane 10, and check whether there is any setup deviation. Determine whether it is a sake cup (
Step S8), in this case, as shown in FIG.
The inclination angle θ before setup and the inclination angle θ, ′ after setup of the vane 1o are determined from the coordinate values of the measurement reference points Po, Pa' and the ends P^, P^'. And the quantity θ in the XY plane
Find Z=θ, −θ□. Similarly, the deviation amount θx in the ZY plane and the deviation amount θY in the XZ plane are determined. When each amount of deviation is not zero, a second correction value is calculated to make each amount of setup deviation zero (step S9).
, and based on the second correction value, ? lI! The coordinate values of the scheduled measurement start points PIJ group are corrected (step 510), and a movement command for the measurement sensor 30 is generated based on the corrected coordinate values of the measurement start points P□J (step 51).
1). If there is no setup deviation amount, a movement command is generated for the measurement sensor 30 based on the coordinate values of the scheduled measurement start point PIJ generated before setup (step 511).
, and the measuring stylus 34 moves to the scheduled measurement start point P according to the movement command.
The measurement sensor 3° is moved until it reaches the rt position (step 512). After this, the measured value 34 is measured at the planned measurement execution point Q
1J, and the measuring sensor 3o is moved until the measuring element 34 comes into contact with the surface of the vane 10. Then, the point where the measuring element 34 abuts on the surface of the vane 10 is set as the measurement execution point, and the coordinate value of this point is measured (step 51
3).

The coordinate values measured by the measurement sensor 30 are displayed on the operation panel 42.
, are input to the dimension inspection device 488 via the numerical control device 46, the coordinate values of the measurement execution point and the coordinate values of the measurement execution point QIJ are compared, and the comparison results are stored on the floppy disk 56 and the printer 52. Output (step 51
4). In this case, when there is no setup deviation, the coordinate values of the measurement execution point are compared with the coordinates of the measurement execution point generated before setup, and when there is a setup deviation, the coordinates of the measurement execution point are corrected. A comparison is made with the coordinate values of the scheduled measurement point.

Next, it is determined whether the measurement result of the measurement execution point is within the judgment reference value (step 515), and if the measurement value is within the measurement reference value, measurement is performed for all the execution planned points QIJ. Step S1 is performed until the measurement is completed for all scheduled measurement points.
Returning to the process of step 2 (step 516), on the other hand, when the measurement result at the measurement execution point deviates from the determination reference value, the coordinate value of this point is stored (step 517).

Next, after the measurements have been completed for all the measurement execution points Q I J, it is determined whether or not there is an abnormal value in the measurement result of the measurement execution point (step 818). If there is no abnormal value, this Finish processing in the routine. on the other hand,
When there is an abnormal value, a pulsation command for marking the abnormal point is generated based on the coordinate value of the measurement execution point whose coordinate value deviates from the judgment reference value (step 5).
19).

Thereafter, the marking head 38 is attached to the tip of the probe 34, and the measurement sensor 30 is moved based on the drive command generated in step S19 to mark the surface of the vane 10 (step 520).

Thereafter, the vane 10 is carried out from the set-up position, and the processing in this routine is completed.

As described above, in this embodiment, even if a positional shift of the measurement reference point and a setup shift due to the inclination of the vane 10 occur during the setup of the vane 10, the determination reference value is determined based on the positioning error associated with the setup of the vane 10. The coordinate values of the scheduled measurement execution point and the scheduled measurement start point were corrected, and the surface shape of the vane 10 was measured based on the corrected coordinate values.
Even if a positioning error of the vane 10 occurs during setup, the dimensions of the vane 10 can be accurately measured without changing setup.

〔Effect of the invention〕

As explained above, according to the present invention, even if a positioning error occurs when setting up a workpiece, the coordinate value of the scheduled measurement start point and the determination reference value are determined based on the correction value to make the positioning error zero. The coordinate values of the scheduled execution point are corrected and the dimensions of the workpiece are inspected based on the corrected coordinate values, so even if a positioning error occurs when setting up the workpiece, the positioning error can be corrected and the workpiece dimensions can be inspected based on the correct position information. It becomes possible to inspect the dimensions of the workpiece, and the dimensions of the workpiece can be accurately measured without changing the setup of the workpiece. Also, when the measured value deviates from the judgment standard value, this /! ! ! Since printing is performed on the surface of the workpiece based on the standard value, it is possible to easily grasp the measurement execution point where the measured value deviates from the judgment reference value.

[Brief explanation of the drawing]

FIG. 1 is a flowchart for explaining the operation of the present invention, FIG. 2 is an overall configuration diagram of a device to which the present invention is applied,
FIG. 3 is a perspective view of the device to which the present invention is applied, FIG. 4 is a perspective view of the measurement sensor 30 of the pulsating part 28, FIG. 5 is a diagram for explaining the drive range of the manipulator 26, and FIG. FIG. 7 is a perspective view of a welded water turbine runner, and FIG. 8 is a perspective view of the vane. FIG. 9 is a diagram for explaining the setup deviation of the vane. 10... Vane, 24... Kousa A, 26...
Manipulator, 28... Active part, 3o... Measurement sensor, 34... Measuring head, 42... Operation panel, 46...
Numerical control device, 48...Dimension inspection device, 50...Display device, 54.56...Floppy disk.

Claims (1)

[Claims] 1. A three-dimensional space of a group of points to be measured that is generated based on a measurement reference point in a group of points to be measured which indicate each grid point when the work surface is divided into a plurality of regions. Pre-setup shape information regarding the reference coordinate values and the inclination of the workpiece with respect to each axis in the three-dimensional space is generated in advance, and an offset value is added to the reference coordinate value of each measurement execution point to create a group of scheduled measurement start points. The coordinate values in the three-dimensional space of are generated based on the reference coordinate values, and the coordinate values in the three-dimensional space of the measurement reference point of the set-up workpiece and the measurement execution point of the workpiece end are respectively measured, and these measured values are generated. The deviation of the measurement reference point before and after setup is calculated from the above, and shape information regarding the inclination of the workpiece with respect to each axis in three-dimensional space is generated, and the amount of setup deviation of the workpiece is calculated from this shape information and the shape information before setup. A first correction value for making the deviation of the measurement reference point zero and a second correction value for making the workpiece setup deviation amount zero are calculated from each of the calculated values, and each correction value is calculated. are added to the coordinate values of each scheduled measurement execution point and each scheduled measurement start point, correct the coordinate values, and sequentially move the measuring stylus to the position where it contacts the workpiece surface based on the corrected coordinate values of the scheduled measurement start point group. A workpiece dimension inspection method in which the coordinate values of each measurement execution point in a three-dimensional space are measured, and the dimensions of the workpiece are inspected by comparing the measured values with corrected reference coordinate values of each measurement execution point. 2. When the comparison value between the measured value and the corrected reference coordinate value deviates from the judgment reference value, the coordinate value of this measurement execution point is memorized, and based on this memorized coordinate value, the abnormal measurement execution point is determined. 2. The method for inspecting dimensions of a workpiece according to claim 1, wherein printing is performed on the workpiece.