JPH07128011A - Three-dimensional measuring instrument - Google Patents

Abstract

PURPOSE:To accurately detect the shape error of an object to be measured by comparing an output signal waveform from a measuring part obtained on actual measurement with each basic pattern and then calculating the deviation of a light reception position for a reference position based on a waveform pattern with the best degree of matching. CONSTITUTION:A robot device 4 which is a cross three-axis robot moves a head 10 while controlling the position (measuring point) of a measuring head 10 and the distance to the surface of a work W and an angle by a controller 5. Then. laser beams from the oscillation element of the head 10 are applied to a specific position on the surface of the work W. the image of a reflection light is formed on a light reflection sensor, and then the image is input to a waveform processing device 6 as a data signal. The device 6 obtains the distance between the surface of the work W and the head 10 and an output waveform indicating the light reception position, selects a waveform pattern with the highest degree of matching with the waveform on actual measurement, and then obtains the deviation of the light reception position for the reference position based on it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional measuring device, and more particularly, it receives reflected light of light projected on the surface of an object to be measured,
The present invention relates to a three-dimensional measuring device that obtains three-dimensional data of an object to be measured from the light receiving state.

[0002]

2. Description of the Related Art Conventionally, as a three-dimensional measuring device for measuring the three-dimensional shape of an article, a light projecting means for projecting light such as a laser beam onto the surface of the article (object to be measured) and a light receiving means for receiving the reflected light thereof. And a driving device such as a robot for moving the measuring head substantially along the surface of the object to be measured and changing the distance or angle of the measuring head with respect to the surface of the object to be measured. A control device for controlling the driving device to move the measuring head to sequentially change the measuring points, and obtain three-dimensional data of the object to be measured based on the light receiving state of the light receiving means at each measuring point. Are known (for example, Japanese Patent Laid-Open No. 2-2
No. 12704). By using such a three-dimensional measuring device, it becomes possible to accurately and automatically measure the shape and size of an article having a considerably complicated three-dimensional shape.

[0003]

When three-dimensional shape measurement is performed by the above-mentioned device, the measuring head is moved substantially along the surface of the object to be measured to sequentially change the measuring points, and at each of these measuring points. Although data is collected for each, conventionally, the collected data is not checked at each measurement point, but a data check is collectively performed after the measurement at all measurement points is completed. When such a measurement point is found, it is common to repeat the measurement for that measurement point. However, with this method, it is necessary to set the measurement head again at the measurement point where unnatural data was found after completing all the measurements, and it takes time and labor, and the work efficiency of measurement / inspection becomes low as a whole. There was a problem in inspection efficiency.

Further, in the three-dimensional measuring apparatus of the above-mentioned type, if the shape and size of the object to be measured at the measurement point are as standard with respect to the light receiving position of the reflected light in the laser displacement meter, the reflected light is received by the light receiving means. Set so that the light is received at the upper reference position, and the deviation of the light receiving position from this reference position
(Displacement) is detected to detect the shape error of the object to be measured at the measurement point, but in such a device, detection accuracy above a certain level is ensured due to, for example, the characteristics of the light receiving element (light receiving means). The regular measurement range that can be done is limited relatively narrowly, and if the distance or angle of the measurement head with respect to the surface of the object to be measured deviates from the preset reference distance or angle by a certain amount or more, the measurement error will be considerably large. There was a problem with inspection accuracy.

That is, when the distance and angle of the measuring head with respect to the surface of the object to be measured are within a certain range (within a measurement allowable range), the signal waveform (output waveform) of the output data signal from the laser displacement meter is As will be described later, it is known that the waveform becomes axisymmetric, and when such a waveform is obtained, its peak is clear and the deviation of the light receiving position from the reference position can be easily read. be able to. However, if the distance or angle of the measuring head with respect to the surface of the object to be measured deviates from the permissible range of measurement, the measurement error becomes large, and some waveform can be obtained from the laser displacement meter. The output waveform does not have a line-symmetric and clear peak as described above.

The present invention has been made in view of the above problems, and improves accuracy in three-dimensional measurement, and further
An object of the present invention is to provide a three-dimensional measuring device capable of improving the work efficiency of inspection.

[0007]

Therefore, the first invention of the present application is to provide a measuring section having a light projecting means for projecting light onto the surface of the object to be measured and a light receiving means for receiving the reflected light, and While moving the measurement unit substantially along the surface of the measured object,
The light receiving means at each measurement point includes drive means for changing the distance or angle of the measurement section with respect to the surface of the object to be measured, and control means for controlling the drive means to move the measurement section to sequentially change the measurement points. A three-dimensional measuring device for obtaining three-dimensional data of the object to be measured based on the light receiving state of the measuring part, which is in accordance with a change state of at least one of a distance and an angle of the measuring part with respect to the surface of the object to be measured. Storage means for respectively storing a plurality of typical waveform patterns of the output signal from the measurement unit as a basic pattern, and the output signal waveform from the measurement unit obtained during actual measurement and each of the basic patterns are compared. Of these basic patterns, the comparison / selection means for selecting the waveform pattern having the highest degree of agreement with the output signal waveform at the time of actual measurement, and the highest degree of agreement It is characterized in that a calculation means for calculating a deviation with respect to a reference position of the light receiving position on the light-receiving unit in the measurement point based on the shape pattern.

A second invention of the present application is the same as the first invention, wherein the storage means stores a predetermined characteristic amount characterizing the waveform of each of the basic patterns, and the comparison / selection means includes: The feature amount of each of the basic patterns is compared with the feature amount of the output signal waveform at the time of actual measurement, and the waveform pattern having the highest degree of matching is selected.

Further, a third invention of the present application is to provide a measuring section having a light projecting means for projecting light on the surface of the object to be measured and a light receiving means for receiving the reflected light, and the measuring section for measuring the object to be measured. Driving means for moving the measuring portion substantially along the surface and changing the distance or angle of the measuring portion with respect to the surface of the object to be measured, and control means for controlling the driving means to move the measuring portion to sequentially change the measuring points. A three-dimensional measuring device for obtaining three-dimensional data of the object to be measured based on the light receiving state of the light receiving means at each measurement point, wherein at least the distance and the angle of the measuring section with respect to the surface of the object to be measured. The waveform pattern of the output signal from the measuring unit and the light receiving position on the light receiving unit according to each change state when either one is sequentially changed are respectively stored as waveform pattern data. The storage means compares the output signal waveform and the light receiving position from the measuring unit obtained during the actual measurement with the waveform pattern data, and outputs the output signal waveform and the light receiving position during the actual measurement in the waveform pattern data. And a comparison / selection unit for selecting the one having the highest degree of coincidence.

Furthermore, a fourth invention of the present application is the same as the third invention, wherein the storage means stores a predetermined characteristic amount characterizing each of the waveform pattern data,
The comparison / selection means is characterized by comparing the feature amount of each waveform pattern data with the feature amount of the output signal waveform at the time of actual measurement and selecting the waveform pattern data having the highest degree of matching. is there.

Further, a fifth invention of the present application is to provide a measuring section having a light projecting means for projecting light onto the surface of the object to be measured and a light receiving means for receiving the reflected light, and the measuring section as described above. Driving means for moving along substantially the surface of the object to be measured, and changing the distance or angle of the measuring part with respect to the surface of the object to be measured,
And a control means for controlling the driving means to move the measuring section to sequentially change the measuring points, and obtain three-dimensional data of the object to be measured based on the light receiving state of the light receiving means at each measuring point. A three-dimensional measuring apparatus, a storage means for storing a waveform pattern of an output signal from the measuring section as a reference pattern when the distance and the angle of the measuring section with respect to the surface of the object to be measured are within the measurement allowable range, and When comparing the output signal waveform from the measurement unit obtained at the time of measurement and the reference pattern, and the degree of match between the output signal waveform at the time of actual measurement and the reference pattern is low, the output signal waveform is A comparison calculation for calculating a correction value for at least one of a distance and an angle of the measurement unit with respect to the surface of the object to be measured based on the measurement point. And a correction unit that corrects the set state of the measurement unit based on the correction value. When the degree of matching between the output signal waveform and the reference pattern is low, the correction unit corrects the measurement unit After correcting the set state, the measurement at the measurement point is performed again.

Further, in the sixth invention of the present application, in the fifth invention, the storage means stores a predetermined characteristic amount characterizing the waveform of the reference pattern, and the comparison calculation means is The feature amount of the reference pattern and the feature amount of the output signal waveform at the time of actual measurement are compared to determine the degree of coincidence between the two.

[0013]

According to the first invention of the present application, since the comparison and selection means and the calculation means are provided, the basic signal stored in the storage means matches the output signal waveform at the time of actual measurement. It is possible to select the waveform pattern having the highest degree of matching and calculate the deviation of the light receiving position on the light receiving means at the measurement point from the reference position based on the waveform pattern having the highest degree of matching. Then, from this deviation, the shape error of the object to be measured at the measurement point can be detected. That is, by sufficiently preliminarily verifying the calculation accuracy of the deviation of the light receiving position from the reference position at the time of appearance of each basic pattern, an output signal having a high degree of agreement with each basic pattern or these basic patterns at the time of actual measurement. The above deviation when the waveform is obtained, in other words, the shape error of the measured object can be accurately detected. Therefore, by selecting the waveform pattern having the highest degree of coincidence with the output waveform obtained at the actual measurement at each measurement point and calculating the deviation, the measurement at each measurement point can be performed accurately. In this case, since the storage means only selects a plurality of typical waveform patterns among various waveform patterns of the output signal from the measurement unit and stores them as basic patterns, it requires a very large memory capacity. There is no such thing. Further, since the deviation of the light receiving position from the reference position can be calculated at the time of measurement at each measurement point, conventionally, after the measurement at all measurement points is completed, a data check is collectively performed and the data is checked by this check. When a physically unnatural measurement point is found, the work efficiency of the measurement / inspection can be significantly improved as compared with the case where the measurement is repeated at that measurement point.

Further, according to the second invention of the present application, basically, the same effect as that of the first invention can be obtained. Moreover, the storage means stores a predetermined characteristic amount characterizing the waveform of each basic pattern, and the comparison and selection means stores the characteristic amount of each basic pattern and the output signal at the time of actual measurement. Since the waveform pattern with the highest degree of matching is selected by comparing with the feature quantity of the waveform, it is easier to select the waveform pattern with the highest degree of matching than when comparing the waveform itself in an analog manner. And it can be done accurately.

Further, according to the third invention of the present application, since the waveform pattern data is stored in the storage means and the comparison / selection means is provided, the actual waveform pattern among the waveform pattern data stored in the storage means is the actual one. It is possible to select the one having the highest degree of agreement with the output signal waveform and the light receiving position at the time of measurement. Then, by making this selection, the light receiving position on the light receiving means (thus, the deviation of the light receiving position from the reference position) can be known. That is, at each measurement point, the shape of the output signal waveform obtained at the time of actual measurement and the waveform pattern data having the highest degree of coincidence with the light receiving position are selected by the comparison / selection means to accurately perform shape measurement at the measurement point. You can Moreover, in this case, by comparing / selecting by the comparison / selection means, it is possible to detect the shape error of the object to be measured without the need of performing a particular calculation process. Also, since the waveform pattern data with the highest degree of matching can be selected at the time of measurement at each measurement point, conventionally, after completing the measurement at all measurement points, a data check is performed collectively and this check is performed. When a measurement point that is unnatural in terms of data is found, it is possible to significantly improve the work efficiency of measurement / inspection as compared with the case where the measurement is repeated at that measurement point.

Further, according to the fourth invention of the present application,
Basically, the same effect as that of the third invention can be obtained. Moreover, the storage means stores a predetermined characteristic amount characterizing each of the waveform pattern data, and the comparison / selection means stores the characteristic amount of each of the waveform pattern data and the output signal at the time of actual measurement. Since the waveform pattern data with the highest degree of matching is selected by comparing with the feature quantity of the waveform, the waveform pattern data with the highest degree of matching can be selected compared to when comparing the waveform itself in an analog manner. It can be done more easily and accurately.

Further, according to the fifth invention of the present application,
Since the comparison calculation means and the correction means are provided, the output signal waveform at the time of actual measurement is compared with the reference pattern, and when the degree of matching between the output signal waveform at the time of actual measurement and the reference pattern is low, , Calculating a correction value for correcting at least one of a distance and an angle of the measurement section with respect to the surface of the object to be measured at the measurement point based on the output signal waveform, and setting the measurement section based on the correction value. The condition can be corrected. That is, the measurement unit can be set within the measurement allowable range. Then, after correcting the set state of the measurement unit by the correction means, the measurement at the measurement point is performed again, so that the distance and angle of the measurement unit with respect to the surface of the measured object are within the measurement allowable range. Measurement can be performed, and highly accurate shape measurement can be performed at the measurement point. In this case, the above re-measurement can be performed without changing the measurement points after the first measurement at each measurement point, so conventionally, data measurement is collectively performed after the measurement at all measurement points is completed. When this check finds a measurement point that is unnatural in terms of data, the measurement / inspection work efficiency can be significantly improved compared to the case where the measurement point is re-measured. .

Further, according to the sixth invention of the present application,
Basically, the same effect as the fifth aspect of the invention can be obtained. In addition, the storage means stores a predetermined feature amount that characterizes the waveform of the reference pattern, and the comparison calculation means stores the feature amount of the reference pattern and the output signal waveform during the actual measurement. Since the degree of coincidence between the two is determined by comparing with the feature amount, the degree of coincidence between the two can be determined more easily and accurately than in the case of comparing the waveforms in an analog manner.

[0019]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 is an explanatory diagram schematically showing the overall configuration of the three-dimensional measuring apparatus 1 according to this embodiment. As shown in this figure, the three-dimensional measuring apparatus 1 is, for example, a sheet metal press-formed product. Surface plate 2 for supporting the work W in a substantially horizontal state, component fixing jigs 3, ..., 3 provided on the surface plate 2 for fixing the lower part of the work W to the surface plate 2, and the surface plate And a gate-shaped robot device 4 arranged so as to surround the work W on the upper part 2.

The robot device 4 includes a pair of left and right columns 4a.
And a ceiling beam 4b provided by connecting the upper ends of both columns 4a to each other, and an elevating arm 4c extending downward from the ceiling beam 4b. A measurement head 10 supported so as to be tiltable so as to face the work W on the board 2 is attached. The robot device 4 is a so-called orthogonal three-axis robot, and the columns 4a, 4a travel in the direction of the paper surface in FIG. 1, and the arm 4c moves in the left-right direction in FIG. 1 along the ceiling beam 4b. By moving up and down in the vertical direction in FIG. 1, the measuring head 10 can be freely moved in three directions of x, y, and z. still,
The drive mechanism of the robot device 4, that is, the columns 4a, 4
Since the traveling mechanism of a, the moving mechanism of the arm 4c and the elevating mechanism, and the tilting mechanism of the measuring head 10 are the same as those well known in the related art, detailed description and illustration thereof are omitted.

The robot device 4 is connected to a controller 5 arranged on the side of the device so that signals can be exchanged.
The operation of the robot apparatus 4, that is, the position (measurement point) of the measuring head 10 and the distance and angle with respect to the surface of the work W are controlled by the control signal from the controller 5. The controller 5 is configured, for example, with a microcomputer as a main part, and basic data regarding the shape and size of the work W is input in advance. Based on this data, a control signal is output to the robot apparatus 4,
The measurement head 10 is controlled so as to move substantially along the surface shape of the work W while sequentially changing the measurement points.

As shown in FIG. 2, the measuring head 10 includes a laser beam driving circuit 12, an oscillating element 13, and a light projecting lens 14 as a light projecting means 11 for three-dimensional measurement, and a light receiving means. 16, the light receiving lens 1
7 and a light receiving sensor 18, and the oscillation element 13
The laser beam from is collected by the light projecting lens 14 and then projected onto a predetermined position on the surface of the work W. After the reflected light is condensed by the light receiving lens 17, the light receiving sensor 1
An image is formed on 8 and a data signal is output. This output data signal is amplified by a signal amplification circuit 19 and then input to a waveform processing device 6 (see FIG. 1) arranged on the side of the robot device 4. It is supposed to be done. As described above, the measuring head 10 is tiltably supported by the arm 4c of the robot apparatus 4 so that the projection light from the light projecting means 11 is accurately projected onto the measurement point of the work W. It can be adjusted.

The waveform processing device 6 is mainly composed of, for example, a microcomputer, and inputs the output data signal from the light receiving sensor 18 amplified by the signal amplifying circuit 19 to the waveform processing device 6. Thus, waveform processing is performed to obtain an output waveform representing the distance between the surface of the work W and the measuring head 10 and the light receiving position on the light receiving sensor 18. Since the light projecting means 11 and the respective constituent elements 12, 13, 14 thereof, and the light receiving means 16 and the constituent elements 17, 18 thereof are the same as those well known in the art, Detailed description and illustration are omitted.

In the measuring head 10, the light receiving sensor 18
Regarding the light receiving position of the reflected light on the upper side, if the shape / dimension of the work W at the measurement point is the reference value, the reflected light is on the reference position on the light receiving sensor 18 (in the present embodiment, the light receiving sensor 18 has the reference position. It is set so that the light is received at the center position in the longitudinal direction), and the deviation (deviation) of the light receiving position from this reference position can be detected to detect the shape error of the work W at the measurement point. . In this embodiment, the light receiving sensor 18 is, for example, a so-called C
A CD type was used. However, in this case, due to the characteristics of the light receiving sensor 18 and the like, the regular measurement range in which the accuracy higher than a certain level can be secured is relatively narrowly limited, and the distance and angle of the measurement head 10 with respect to the surface of the work W (measurement head 10 If the (set state) deviates from the preset reference distance or angle by a certain amount or more, the measurement error becomes considerably large.

That is, when the distance or angle of the measuring head 10 with respect to the surface of the work W is within a certain range with respect to the setting reference (that is, within the measurement allowable range), the output data signal of the light receiving sensor 18 Signal waveform (output signal waveform)
Is known to have a line-symmetrical waveform, as shown in FIG. 3, and when such a waveform is obtained,
The peak is clear, and the deviation of the light receiving position from the reference position can be easily read. On the other hand, when the distance or the angle of the measuring head 10 with respect to the surface of the work W deviates from the measurement allowable range, the measurement error becomes large, and the output signal waveform from the light receiving sensor 18 does not have any waveform. However, the waveform does not have a line-symmetric and clear peak as described above.

For example, when the angle of the measuring head 10 with respect to the surface of the work W is excessively inclined beyond the above measurement allowable range, the obtained output signal waveform has a peak as shown in FIG. 4, for example. However, the waveform of the object does not have line symmetry, and it becomes difficult to specify the light receiving position. Also, for example,
When the distance from the surface of the workpiece W of the measuring head 10 deviates from the above measurement allowable range and the focus is deviated, the obtained output signal waveform has a peak shape whose peak is not clear as shown in FIG. 5, for example. Waveform, and it becomes more difficult to specify the light receiving position.

In the present embodiment, although not specifically shown, the work W of the measuring head 10 is added to the waveform processing device 6.
Of the waveform patterns of the output data signal from the measuring head 10 obtained according to the change state of at least one of the distance and the angle with respect to the surface, a plurality of preselected representative waveform patterns are respectively used as basic patterns. An output signal waveform from the measuring head 10 obtained at the time of actual measurement at each measurement point is compared with each of the above-mentioned basic patterns, and the output signal waveform at the time of the actual measurement among these basic patterns is stored. And a comparison / selection unit that selects the waveform pattern with the highest degree of matching, and a calculation unit that calculates the deviation of the light receiving position on the light receiving unit at the measurement point from the reference position based on the waveform pattern with the highest degree of matching. Is equipped with.

Further, in the present embodiment, the storage unit stores a predetermined feature amount that characterizes the waveform of each of the basic patterns. That is, each of the basic patterns, when the distance or angle of the measuring head 10 with respect to the surface of the work W is changed, from the waveform pattern of the output data signal from the measuring head 10 obtained according to the change state,
Although a plurality of types of typical waveform patterns (for example, the waveform patterns shown in FIGS. 3 to 5) are selected, the storage unit stores, for each of these basic patterns, a characteristic amount that characterizes the waveform. For example, a to e shown below
The respective feature quantities of are stored. -A: width from the reaction start of the light-receiving sensor 18 to the end of reaction (see Fig. 3) -b: reaction peak height of the light-receiving sensor 18 (see Fig. 3) -c: width of the peak midpoint of the light-receiving sensor 18 (Fig. 3) ・ d: Deviation between the reaction midpoint of the light receiving sensor 18 and the waveform peak (see Fig. 4) ・ e: Total reaction output of the light receiving sensor 18 (see Fig. 5)

Next, the measuring procedure and determination of the output signal waveform at each measuring point by the above-mentioned three-dimensional measuring apparatus 1 will be described with reference to the flowchart of FIG.
After the measurement head 10 is moved to the measurement point, the measurement head 10 is positioned, and the work W of the measurement head 10 is further positioned.
When the setting of the distance and the angle with respect to the surface is completed, the three-dimensional measurement at the measurement point is started. That is, first, the drive circuit 12 of the light projecting means 11 is turned on (step # 1), the laser beam is projected on the surface of the work W (step # 2), and the reflected light is received by the light receiving means 16 (step # 3). The sensor output (output data signal) from the light receiving sensor 18 is amplified by the signal amplification circuit 19.
(Step # 4) and then input to the waveform processing device 6,
The waveform processing device 6 determines the output waveform (step # 5).

The determination of the output waveform is performed by the comparison / selection unit of the waveform processing device 6, and the output signal waveform obtained by the actual measurement is measured in the distance or angle with respect to the surface of the workpiece W of the measuring head 10 within the allowable measurement range. It is determined whether or not the waveform is a line-symmetrical waveform (see FIG. 3) obtained in the case of being inside. In this case, the characteristic quantities a to e which characterize the output signal waveform at the time of the actual measurement are extracted, and more preferably, the characteristic quantity of this output signal waveform and the characteristic quantity of the line-symmetrical waveform which is one of the basic patterns. And are compared. Then, the determination is made based on whether or not the both match, that is, whether or not the matching degree between the both is equal to or more than a predetermined value.

When the determination result in step # 5 is OK, that is, when the output signal waveform is a line-symmetrical waveform, the reaction intermediate point of the light receiving sensor 18 and the waveform peak are well understood from FIG. Since P and P coincide with each other on the coordinates indicating the pixel position of the sensor 18, the light receiving position can be specified easily and accurately, and the displacement amount (deviation) Xp of this light receiving position from the reference position O is calculated. (Step # 9). Then, the calculated data is stored in the memory device (not shown) attached to the waveform processing device 6 (step # 10). As a result, since the measurement at the measurement point is completed, the robot apparatus 4 is driven next (step # 11), and the measurement point is changed to the next point (step # 12).
It is like this.

On the other hand, the judgment result in step # 5 is N.
In the case of G, that is, when the output signal waveform is not a line-symmetrical waveform, in step # 6, the waveform processing device 6 performs the matching of the waveform patterns, and among the basic patterns, the output signal waveform at the time of actual measurement is used. The waveform pattern with the highest degree of matching is selected. In this matching, the feature amount of each basic pattern is compared with the feature amount of the output signal waveform, and the one having the highest degree of coincidence is selected. Then, in step # 7, the amount of displacement of the light receiving position on the light receiving sensor 18 from the reference position O according to the selected basic pattern.
(Deviation) is calculated.

That is, for example, as shown in FIG.
Although the waveform peak is clearly recognized, in the case of a waveform pattern in which the reaction intermediate point Q of the light receiving sensor 18 and the waveform peak position are deviated, the reaction intermediate point Q is set as the light receiving position, and the reference position O of this light receiving position is set. The displacement amount (deviation) Xq of is calculated. Further, for example, as shown in FIG. 5, in the case of a mountain-shaped waveform pattern in which no clear peak is recognized, the position of the center of gravity of the reaction total output of the light receiving sensor 18, that is, the center of gravity G on the area of the mountain-shaped waveform is received. As a position, a displacement amount (deviation) Xg of this light receiving position from the reference position O is calculated. In this case, when the waveform pattern as described above (see FIGS. 4 and 5) is obtained, it is sufficient to apply the above calculation method as the calculation of the deviation of the light receiving position from the reference position. It has been verified in advance that high calculation accuracy can be ensured. The data calculated in this way is stored in the memory device (not shown) attached to the waveform processing device 6 (step # 8), whereby the measurement at the measurement point is completed. And above step #
The steps after 11 are executed, and the measurement point is changed to the next point.

As described above, according to the present embodiment, the surface of the work W of the measuring head 10 among the respective basic patterns stored in the storage unit by the comparison and selection unit provided in the waveform processing device 6 is described. Select the waveform pattern that has the highest degree of matching with the output signal waveform at the time of actual measurement, including the one with the line-symmetrical waveform pattern obtained when the distance or angle is within the measurement allowable range. Based on the highest waveform pattern, the deviations Xp, Xq, Xg of the light receiving position on the light receiving sensor 18 at the measurement point from the reference position O can be calculated. Then, the shape error of the work W at the measurement point can be detected from the deviations Xp, Xq, and Xg. That is, by sufficiently verifying in advance the calculation accuracy of the deviations Xp, Xq, and Xg of the light receiving position with respect to the reference position O at the time of appearance of each basic pattern, it is possible to compare the above basic patterns or these basic patterns at the time of actual measurement. It is possible to accurately detect the deviations Xp, Xq, Xg, in other words, the shape error of the work W when the output signal waveform having a high degree of coincidence is obtained. Therefore, by selecting the waveform pattern that has the highest degree of agreement with the output waveform obtained at the actual measurement at each measurement point and calculating the deviations Xp, Xq, Xg, the measurement at each measurement point can be performed accurately. It can be done.

In this case, since the storage section only selects a plurality of typical waveform patterns among various waveform patterns of the output data signal from the measuring head 10 and stores them as basic patterns, it is a very large memory. No capacity is needed. Further, since the calculation of the deviations Xp, Xq, Xg of the light receiving position with respect to the reference position O can be performed at the time of measurement at each measurement point, conventionally, a data check is collectively performed after the measurement at all measurement points is completed. When this check is performed and a measurement point that is unnatural in terms of data is found, the work efficiency of measurement / inspection can be significantly improved compared to the case where the measurement is repeated at that measurement point.

Further, the storage unit stores a predetermined feature amount characterizing the waveform of each of the basic patterns, and the comparison and selection unit outputs the feature amount of each of the basic patterns and the output signal at the time of actual measurement. By comparing the feature quantity of the waveform and selecting the waveform pattern with the highest degree of matching,
As compared with the case where the waveforms themselves are compared in an analog manner, the waveform pattern having the highest degree of matching can be selected more easily and accurately.

In the above embodiment, a plurality of typical waveform patterns among various waveform patterns of the output data signal from the measuring head 10 are selected and stored as basic patterns in the storage unit. The pattern having the highest degree of matching with the output signal waveform obtained during actual measurement is selected from the patterns, and the light receiving position on the light receiving sensor 18 at the measurement point is selected according to the waveform of the selected basic pattern. Although the deviations Xp, Xq, Xg with respect to the reference position O are calculated, the deviation of the light receiving position with respect to the reference position can be detected without performing such calculation.

In this case, in the storage unit of the waveform processing device,
The waveform pattern of the output signal from the measuring head 10 and the light receiving position on the light receiving means 16 according to each change state when at least one of the distance and the angle of the measuring head 10 with respect to the surface of the work W is sequentially changed. Are respectively stored as waveform pattern data, the output signal waveform and the light receiving position from the measuring head 10 obtained at the time of actual measurement are compared with the waveform pattern data, and among the waveform pattern data, at the time of actual measurement. A comparison / selection unit is provided for selecting the one having the highest degree of agreement with the output signal waveform and the light receiving position.

When such a configuration is adopted, the measuring head 10 is stored in the storage unit in accordance with each change state when the distance and the angle of the measuring head 10 with respect to the surface of the work W are sequentially changed for each measuring point. Since the waveform pattern of the output signal from and the light receiving position on the light receiving means 16 are stored as an extremely large number of waveform pattern data, the output signal at the time of the actual measurement among the waveform pattern data by the comparison and selection section. By selecting the one having the highest degree of coincidence with the waveform and the light receiving position, it is possible to immediately know the light receiving position on the light receiving sensor 18 (therefore, the deviation of this light receiving position from the reference position). That is, the output signal waveform obtained at the time of actual measurement at each measurement point and the waveform pattern data having the highest degree of coincidence with the light receiving position are selected by the comparison and selection unit, so that the calculation point does not need to be calculated. The shape can be measured with high precision.

Also in this case, the waveform pattern data having the highest degree of matching can be selected at the time of measurement at each measurement point, so that conventionally, the measurement is collectively performed after the measurement at all measurement points is completed. When a data check is performed and a measurement point that is unnatural in terms of data is found by this check, the work efficiency of measurement / inspection will be greatly improved compared to the case where the measurement is repeated at that measurement point. You can

Further, as in the case of the above-described embodiment, a predetermined characteristic amount characterizing each of the waveform pattern data is stored in the storage unit, and the comparison / selection unit stores the waveform pattern data. By comparing the feature amount and the feature amount of the output signal waveform at the time of actual measurement and selecting the waveform pattern data with the highest degree of matching, compared to the case of comparing the waveform itself in an analog manner, The waveform pattern data with the highest degree of matching can be selected more easily and accurately.

Next, another embodiment of the present invention will be described. In the description of the present embodiment, the same components as those in the above-described embodiment described with reference to FIGS. 1 to 6 are designated by the same reference numerals and further description will be omitted. In the present embodiment, the waveform pattern of the output signal from the measuring head 10 (see FIG. 3) when the distance and the angle of the measuring head 10 to the surface of the work W are within the measurement allowable range is stored in the storage unit of the waveform processing device. It is stored as a reference pattern. In this case, the storage unit stores predetermined feature quantities (a to c) that characterize the waveform of the reference pattern. Further, the output signal waveform from the measuring head 10 obtained in the actual measurement is compared with the reference pattern, and when the output signal waveform in the actual measurement and the reference pattern do not match, that is, the matching degree is low. In this case, a comparison calculation unit is provided that calculates a correction value for at least one of a distance and an angle of the measurement head 10 with respect to the surface of the work W at the measurement point based on the output signal waveform. In this case, the comparison calculation unit is
The feature amount of the waveform of the reference pattern and the feature amount of the output signal waveform at the time of the actual measurement are compared to determine the degree of coincidence between the two.

Next, the measuring procedure at each measuring point by the three-dimensional measuring apparatus according to this embodiment will be described with reference to the flowchart of FIG. Here, the execution contents in each of the steps # 21 to # 25 and the steps # 29 to # 32 in the flowchart of FIG. 7 are the steps # 1 to # 5 and the steps in the flowchart shown in FIG. Since it is the same as the contents executed in each step of # 9 to step # 12,
A description of these steps will be omitted. If the determination result in step # 25 is NG, that is, if the output signal waveform is not a line-symmetrical waveform and does not match the reference pattern or the matching degree is lower than a predetermined value, in step # 6, the light receiving sensor is detected. An approximate value of a displacement amount (deviation) of the light receiving position on 18 from the reference position O is calculated. For example, in the case of a defocused waveform as shown in FIG. 5, the estimated value is roughly read as a peak position of a mountain-shaped waveform, and the read peak position is assumed to be a light receiving position. Then, it is obtained by calculating the displacement amount from the reference position O.

Next, the robot apparatus 4 is driven so that the distance and angle (the set state of the measuring head 10) of the measuring head 10 with respect to the surface of the work W at the measuring point are within the measurement allowable range (step # 27), the distance and angle of the measuring head 10 with respect to the surface of the work W (only the distance in the case of defocus) is adjusted (step # 2).
8). As the correction value for this adjustment, the approximate value of the displacement amount calculated in step # 26 is used. Then, after this adjustment, that is, the correction of the set state of the measuring head 10, is completed, the process returns to step # 21 and the measurement at the measurement point is performed again.

As described above, according to this embodiment, since the comparison operation section and the correction section are provided, the output signal waveform at the time of actual measurement is compared with the reference pattern, and at the time of actual measurement. When the degree of matching between the output signal waveform of the measurement head 10 and the reference pattern is low, correction is performed to correct at least one of the distance and the angle of the measurement head 10 with respect to the surface of the workpiece W at the measurement point based on the output signal waveform. A value can be calculated and the set state of the measuring head 10 can be corrected based on this correction value. That is, the measuring head 10 can be set within the measurement allowable range. Then, after the robot apparatus 4 is driven to correct the set state of the measurement head 10, the measurement at the measurement point is performed again. Therefore, the distance and angle of the measurement head 10 with respect to the surface of the work W are within the measurement allowable range. It is possible to perform the re-measurement in the state of, and it is possible to perform the highly accurate shape measurement at the measurement point. In this case, the above re-measurement can be performed without changing the measurement point after the first measurement at each measurement point.
Conventionally, after checking all the measurement points, a data check is collectively performed, and if a measurement point that is unnatural in terms of data is found by this check, it is necessary to repeat the measurement for that measurement point. hand,
The work efficiency of measurement / inspection can be greatly improved.

Further, the storage unit stores a predetermined feature amount (a to c) characterizing the waveform of the reference pattern, and the comparison calculation unit stores the feature amount of the reference pattern and the actual measurement value. Since the degree of coincidence between the two is determined by comparing with the feature amount of the output signal waveform, the degree of coincidence between the both is determined more easily and accurately than in the case of comparing the waveforms in analog form. It is possible.

[Brief description of drawings]

FIG. 1 is an explanatory diagram schematically showing the overall configuration of a three-dimensional measuring apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a measuring head of the three-dimensional measuring device.

FIG. 3 is a diagram showing an example of an output waveform when the measuring head is within a measurement allowable range.

FIG. 4 is a diagram showing an example of an output waveform when the inclination angle of the measuring head with respect to the work surface is too large.

FIG. 5 is a diagram showing an example of an output waveform when the focus is deviated.

FIG. 6 is a flow chart for explaining the operation of the coordinate measuring apparatus.

FIG. 7 is a flow chart for explaining the operation of the coordinate measuring apparatus according to another embodiment of the present invention.

[Explanation of symbols]

 1 ... Three-dimensional measuring device 4 ... Robot device 5 ... Controller 6 ... Waveform processing device 10 ... Measuring head 11 ... Light emitting means 16 ... Light receiving means 18 ... Light receiving sensor a, b, c, d, e ... Waveform feature amount W … Work Xg, Xp, Xq… Deviation

Claims (6)

[Claims] 1. A measuring section having a light projecting means for projecting light onto the surface of the object to be measured and a light receiving means for receiving the reflected light thereof,
While moving the measurement unit substantially along the surface of the object to be measured, driving means for changing the distance or angle of the measurement unit with respect to the surface of the object to be measured, and controlling the driving unit to move the measurement unit to perform measurement. A three-dimensional measuring device comprising control means for sequentially changing points, and which obtains three-dimensional data of the object to be measured based on the light receiving state of the light receiving means at each measurement point, the object to be measured of the measuring section. Storage means for storing as a basic pattern a plurality of typical waveform patterns of the output signal from the measuring unit according to the change state of at least one of the distance and the angle with respect to the surface of the object, and obtained in actual measurement The output signal waveform from the measurement unit is compared with each of the basic patterns, and among these basic patterns, the wave that has the highest degree of agreement with the output signal waveform at the time of actual measurement. A comparison and selection unit for selecting a shape pattern, and a calculation unit for calculating a deviation of a light receiving position on the light receiving unit at the measurement point from a reference position based on the waveform pattern having the highest degree of matching. 3D measuring device. 2. The three-dimensional measuring apparatus according to claim 1, wherein the storage means stores a predetermined feature amount characterizing the waveform of each of the basic patterns, and the comparison and selection means includes each of the A three-dimensional measuring apparatus characterized in that the feature amount of a basic pattern and the feature amount of an output signal waveform at the time of actual measurement are compared to select the waveform pattern having the highest degree of matching. 3. A measuring section having a light projecting means for projecting light onto the surface of the object to be measured and a light receiving means for receiving the reflected light thereof,
While moving the measurement unit substantially along the surface of the object to be measured, driving means for changing the distance or angle of the measurement unit with respect to the surface of the object to be measured, and controlling the driving unit to move the measurement unit to perform measurement. A three-dimensional measuring device comprising control means for sequentially changing points, and which obtains three-dimensional data of the object to be measured based on the light receiving state of the light receiving means at each measurement point, the object to be measured of the measuring section. The waveform pattern of the output signal from the measuring unit and the light receiving position on the light receiving means according to each change state when at least one of the distance and the angle with respect to the object surface are sequentially changed are respectively stored as waveform pattern data. The waveform pattern data is compared with the storage means for storing, the output signal waveform and the light receiving position from the measuring section obtained during the actual measurement, and the waveform pattern data. A three-dimensional measuring device comprising: a comparison and selection unit that selects one of the turn data that has the highest degree of coincidence with the output signal waveform and the light receiving position at the time of actual measurement. 4. The three-dimensional measuring apparatus according to claim 3, wherein the storage means stores a predetermined feature amount characterizing each of the waveform pattern data, and the comparison and selection means includes each of the waveforms. A three-dimensional measuring apparatus characterized by comparing the characteristic amount of pattern data with the characteristic amount of an output signal waveform at the time of actual measurement and selecting the waveform pattern data having the highest degree of matching. 5. A measuring section having a light projecting means for projecting light onto the surface of the object to be measured and a light receiving means for receiving the reflected light thereof,
While moving the measurement unit substantially along the surface of the object to be measured, driving means for changing the distance or angle of the measurement unit with respect to the surface of the object to be measured, and controlling the driving unit to move the measurement unit to perform measurement. A three-dimensional measuring device comprising control means for sequentially changing points, and which obtains three-dimensional data of the object to be measured based on the light receiving state of the light receiving means at each measurement point, the object to be measured of the measuring section. Storage means for storing the waveform pattern of the output signal from the measuring unit as a reference pattern when the distance and angle with respect to the object surface are within the measurement allowable range, and the output signal waveform from the measuring unit obtained during actual measurement And the reference pattern are compared, and if the degree of matching between the output signal waveform at the time of the actual measurement and the reference pattern is low, the measurement is performed based on the output signal waveform. Comparing calculation means for calculating a correction value for at least one of the distance and the angle of the measuring part with respect to the surface of the object to be measured at the point, and the correcting means for correcting the set state of the measuring part based on the correction value. When the degree of matching between the output signal waveform and the reference pattern is low, the correction means corrects the set state of the measurement unit, and then the measurement at the measurement point is performed again. 3D measuring device. 6. The three-dimensional measuring apparatus according to claim 5, wherein the storage unit stores a predetermined feature amount that characterizes the waveform of the reference pattern, and the comparison calculation unit includes the reference pattern. The three-dimensional measuring apparatus characterized in that the feature amount of the above is compared with the feature amount of the output signal waveform at the time of the actual measurement to determine the degree of coincidence between the two.