JP2021189143A - Three-dimensional measuring machine and data processing device - Google Patents

Abstract

To provide a three-dimensional measuring machine that suppresses the occurrence of noise in shape measurement data.SOLUTION: A three-dimensional measuring machine 1 comprises: an irradiation section 2 for irradiating an object to be measured with a laser beam; an imaging section 3 that captures the laser beam reflected by the object to be measured and generates a captured image including one or more pixel columns; a determination section 46 that calculates a parameter obtained by digitizing degree of change using normal distribution as a reference and determines whether or not the calculated parameter satisfies a predetermined numerical condition with respect to light intensity distribution indicated by the pixel columns; and a shape measurement section 44 for generating shape measurement data of the object to be measured on the basis of the pixel columns indicating the light intensity distribution for which it is determined that the parameter satisfies the numerical condition.SELECTED DRAWING: Figure 1

Description

The present invention relates to a non-contact type three-dimensional measuring machine and a data processing device.

Conventionally, a non-contact coordinate measuring machine that measures the shape of a measurement object by irradiating the measurement object with a laser beam and imaging the light reflected by the measurement object has been known (for example, a patent). See Document 1).
Such non-contact type three-dimensional measuring machines include a line-type three-dimensional measuring machine that irradiates a measurement object with a line-shaped laser beam and a flying spot type that scans a point-shaped laser beam on the measurement object. There is a 3D measuring machine. In all types of CMMs, it is common to calculate the distance to the measurement site irradiated with laser light by performing arithmetic processing based on the light intensity distribution of the captured image according to the principle of triangulation. ing.

Japanese Unexamined Patent Publication No. 2015-141372

However, in the non-contact type three-dimensional measuring machine as described above, the light intensity distribution of the captured image may deviate from the ideal range depending on the state of the measurement site (for example, shape, reflectance, etc.) of the object to be measured. .. In such a case, the distance to the measurement site is not calculated accurately, and the data corresponding to the measurement site becomes noise in the shape measurement data of the entire measurement object.

An object of the present invention is to provide a coordinate measuring machine and a data processing device that suppress the generation of noise in shape measurement data.

The three-dimensional measuring machine of the present invention captures an irradiation unit that irradiates a measurement object with a laser beam and the laser beam reflected by the measurement object, and generates an captured image including one or more rows of pixels. For the image pickup unit and the light intensity distribution indicated by the pixel sequence, a parameter that quantifies the degree of change based on the normal distribution is calculated, and a determination is made to determine whether or not the calculated parameter satisfies a predetermined numerical value. It is characterized by including a unit and a shape measuring unit that generates shape measurement data of the object to be measured based on the pixel sequence showing the light intensity distribution for which the parameter is determined to satisfy the numerical condition. do.

In the present invention, among the captured images captured by the imaging unit, the pixel strings showing the light intensity distribution whose parameters do not satisfy the numerical conditions are excluded from the valid data as data that can generate noise. On the other hand, among the captured images captured by the imaging unit, the pixel strings showing the light intensity distribution whose parameters satisfy the numerical conditions are used to generate the shape measurement data of the object to be measured as reliable effective data. To.
That is, in the present invention, the captured image data for generating the shape measurement data of the object to be measured is selected based on the reliability. Therefore, it is possible to suppress the generation of noise in the shape generation data.

In the three-dimensional measuring machine of the present invention, the determination unit determines one or more of the parameters of the light intensity distribution indicated by the pixel sequence, which is at least one of skewness, kurtosis, variance, peak level, or number of peaks. It is preferable to calculate and determine whether or not the calculated parameter satisfies the numerical value set for each parameter.
According to the present invention as described above, the captured image that can generate noise can be suitably removed from the valid data.

The shape measuring method of the present invention is a shape measuring method based on an image taken by capturing an image of a laser beam reflected by an object to be measured and including one or more rows of pixels, wherein the pixel rows are With respect to the indicated light intensity distribution, a determination step of calculating a parameter that quantifies the degree of change based on a normal distribution and determining whether or not the calculated parameter satisfies a predetermined numerical condition, and the parameter is the numerical value. It is characterized by carrying out a shape measurement step of generating shape measurement data of the measurement object based on the pixel array showing the light intensity distribution determined to satisfy the conditions.
According to the present invention, the same effect as that of the above-mentioned three-dimensional measuring machine of the present invention is obtained.

The data processing apparatus of the present invention is an image obtained by capturing a laser beam reflected by a measurement object, and is an image acquisition unit that acquires an captured image including one or more rows of pixels, and a light intensity indicated by the pixel rows. With respect to the distribution, a determination unit that calculates a parameter that quantifies the degree of change based on the normal distribution and determines whether or not the calculated parameter satisfies a predetermined numerical condition, and the parameter satisfies the numerical value. It is characterized by comprising a shape measuring unit for generating shape measurement data of the measurement object based on the pixel row showing the light intensity distribution determined to be.
According to the present invention, the same effect as that of the above-mentioned three-dimensional measuring machine of the present invention is obtained.

The block diagram which shows the structure of the 3D measuring machine which concerns on one Embodiment of this invention. The figure which shows typically the optical element of the 3D measuring machine which concerns on the said embodiment. The figure which shows the setting screen for setting the numerical condition of each parameter which concerns on the said embodiment. The figure which shows the measurement part of the measurement object, the beam spot formed in a linear image sensor, and the example of the light intensity distribution of a captured image. The figure which shows the measurement site of the measurement object, the beam spot formed in a linear image sensor, and other examples of the light intensity distribution of a captured image. The figure which shows the measurement site of the measurement object, the beam spot formed in a linear image sensor, and other examples of the light intensity distribution of a captured image. The figure which shows the measurement site of the measurement object, the beam spot formed in a linear image sensor, and other examples of the light intensity distribution of a captured image. The figure which shows the measurement site of the measurement object, the beam spot formed in a linear image sensor, and other examples of the light intensity distribution of a captured image. The figure which shows the measurement site of the measurement object, the beam spot formed in a linear image sensor, and other examples of the light intensity distribution of a captured image. The figure explaining the 1st parameter which concerns on the said Embodiment. The figure explaining the 2nd parameter which concerns on the said Embodiment. The figure explaining the 3rd parameter which concerns on the said Embodiment. The figure explaining the 4th parameter which concerns on the said Embodiment. The figure explaining the 5th parameter which concerns on the said Embodiment. The figure which shows the example of the probe module and the measurement object of the said embodiment. The figure which shows the probe module of the said embodiment and another example of a measurement object.

An embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, the three-dimensional measuring machine 1 is a flying spot type device, and irradiates the measurement object W with the laser light L while changing the irradiation direction of the laser light L (point laser), and the measurement object W is used. The shape of the object to be measured W is measured by imaging the reflected laser beam L.

Specifically, as shown in FIG. 1, the coordinate measuring machine 1 has a probe unit 10 that emits and images a laser beam, a control unit 4 that controls the probe unit 10, and a storage that stores various data. A unit 5 and an operation unit 6 and a display unit 7 connected to the control unit 4 are provided.

The probe unit 10 is supported by a moving mechanism (not shown) that can move the probe unit 10 with respect to the object W to be measured, and has an irradiation unit 2 and an image pickup unit 3. The configuration of the moving mechanism that supports the probe unit 10 is the same as that of the prior art, and may be a portal type or an arm type.

The irradiation unit 2 includes a light source 21 that emits a laser beam L, a light source driving unit 22 that drives the light source 21, and an irradiation optical system 23.
The light source 21 is, for example, a laser diode, and emits a laser beam having an amount of light corresponding to the drive voltage applied from the light source drive unit 22.
The irradiation optical system 23 is an optical system that irradiates the measurement object W with the laser beam emitted from the light source 21. The irradiation optical system 23 includes, for example, a collimating lens that parallelizes the laser beam L emitted from the light source 21, and an irradiation side scanning mirror (for example, a galvano mirror or the like) that changes the irradiation direction of the laser beam. The light source.

The image pickup unit 3 includes a light receiving optical system 31, a linear image sensor 32 that receives laser light L via the light receiving optical system 31, and a signal processing unit 33.
The light receiving optical system 31 is an optical system that guides the laser beam L reflected by the measurement object W to the linear image sensor 32. The light receiving optical system 31 is, for example, a collection of light receiving side scanning mirrors (for example, a galvano mirror or the like) that reflect the laser light L reflected by the measurement object W and the laser light reflected by the light receiving side scanning mirror. Consists of including an optical lens.

The linear image sensor 32 has a plurality of light receiving elements arranged linearly along one direction, and these plurality of light receiving elements constitute a light receiving surface of the linear image sensor 32. Further, each light receiving element of the linear image sensor 32 accumulates electric charges according to the amount of light received.
The signal processing unit 33 sequentially reads out the charges accumulated in each light receiving element of the linear image sensor 32 and performs signal processing to generate an captured image.
In the present embodiment, the image pickup unit 3 generates a one-dimensional image with one row of pixels as a captured image, and this captured image is represented as digital waveform data indicating light intensity.

Note that FIG. 2 is a schematic diagram showing the optical elements constituting the probe unit 10 in a simplified manner. As shown in FIG. 2, the optical axis of the laser beam L that the irradiation unit 2 irradiates the measurement object W and the optical axis of the laser light L that is reflected by the measurement object W and is incident on the image pickup unit 3 are predetermined. Arranged at an angle.

The control unit 4 corresponds to the data processing device of the present invention. The control unit 4 is, for example, a CPU (Central Processing Unit), and by executing a program stored in the storage unit 5, the light source control unit 41, the scanning control unit 42, the image acquisition unit 43, the shape measurement unit 44, It functions as a condition setting unit 45, a determination unit 46, and a display control unit 47. The control unit 4 is connected to the probe unit 10 or the like by wire or wirelessly.

The light source control unit 41 adjusts the amount of light of the laser beam L emitted from the light source 21 by controlling the light source drive unit 22. The light source control unit 41 may feedback control the light source drive unit 22 in order to avoid saturation of the accumulated charge of each light receiving element of the linear image sensor 32.

The scanning control unit 42 controls so that the irradiation side scanning mirror of the irradiation optical system 23 and the light receiving side scanning mirror of the light receiving optical system 31 are synchronously driven. As a result, the laser light L emitted from the irradiation unit 2 scans the measurement object W, and the laser light reflected by the measurement object W is incident on the image pickup unit 3. Further, the scanning control unit 42 may move the probe unit 10 in a direction orthogonal to the scanning direction by controlling the moving mechanism that supports the probe unit 10.

The image acquisition unit 43 acquires an image to be captured from the image pickup unit 3 at a predetermined sampling cycle while the laser beam L scans the object W to be measured. As a result, the image acquisition unit 43 acquires a plurality of captured images corresponding to each measurement site of the measurement object W. The acquired captured image is stored in the storage unit 5.

The shape measuring unit 44 calculates the distance to the measurement site on the surface of the measurement object W based on the captured image.
For example, when the measurement portion of the measurement object W is displaced as shown in FIG. 2, the optical path of the laser beam reflected at the measurement portion and incident on the image pickup unit 3 changes as shown by a broken line. As a result, the position of the beam spot formed on the light receiving surface of the linear image sensor 32 moves, and the light intensity distribution of the captured image changes. Therefore, the shape measuring unit 44 can calculate the distance to the measurement site of the measurement object W based on the peak and the center of gravity in the light intensity distribution of the captured image.
The light intensity distribution of the captured image represents a change in light intensity along the arrangement direction of the pixel rows forming the captured image. In the present embodiment, since the captured image is formed from a single row of pixel rows, the light intensity distribution of the captured image corresponds to the "light intensity distribution indicated by the pixel row" of the present invention.

Further, the shape measuring unit 44 generates shape measurement data of the measurement target object based on a plurality of captured images corresponding to each measurement site of the measurement target object W. Specifically, the measurement site of the measurement object W is based on the distance to the measurement site calculated for each captured image, the irradiation angle of the laser beam L at the time of acquiring each captured image, and the position of the probe unit 10. Calculate the three-dimensional coordinates for each.
The irradiation angle of the laser beam L can be calculated based on the detection value of the angle sensor provided on the irradiation side scanning mirror of the irradiation optical system 23, and the position of the probe unit 10 is a moving mechanism that supports the probe unit 10. It can be calculated based on the detected value of the displacement sensor provided in.

The condition setting unit 45 can set numerical conditions for each of the first to fifth parameters based on the setting information input via, for example, the operation unit 6.
Here, the first to fifth parameters are information that numerically indicates the degree of change of the light intensity distribution of the captured image with respect to the normal distribution. In this embodiment, the first to fifth parameters correspond to skewness, kurtosis, variance, peak level, and number of peaks, respectively. Details of the first to fifth parameters will be described later.
The numerical condition is a condition for designating a predetermined numerical value or a numerical range, and can be set for each of the first to fifth parameters, and is set for at least one or more parameters. This numerical condition is a condition for the captured image to be treated as valid data, and is hereinafter referred to as a filter condition.

The determination unit 46 calculates the first to fifth parameters of the light intensity distribution of the captured image, and determines whether or not the first to fifth parameters satisfy the filter conditions set for each. In the present embodiment, the determination unit 46 determines that the captured image satisfying the set filter condition is valid data for the first to fifth parameters, and at least one first to fifth parameter satisfies the filter condition. It is determined that the captured image that does not exist is invalid data.
The captured image determined to be valid data is the data used for shape measurement by the shape measurement unit 44 described above.

The display control unit 47 can display the shape measurement data on the display unit 7 by graphic processing (for example, plotting processing to three-dimensional coordinates). Further, as shown in FIG. 3, the display control unit 47 can display the setting screen 9 of each filter condition of the first to fifth parameters on the display unit 7. The setting screen 9 will be described later.

The storage unit 5 stores a program for operating the control unit 4, an captured image acquired by the image acquisition unit 43, and the like.
The operation unit 6 is, for example, a keyboard, and the display unit 7 is, for example, a liquid crystal display.

(Captured image)
Hereinafter, the relationship between the measurement site of the measurement object W, the beam spot formed on the light receiving surface of the linear image sensor 32, and the light intensity distribution of the captured image will be described with reference to FIGS. 4 to 9. In the light intensity distributions shown in FIGS. 4 to 9, the horizontal direction corresponds to the arrangement direction of the pixels, and the vertical direction corresponds to the light intensity of each pixel. Further, in FIGS. 4 to 9, only the linear image sensor 32 of the image pickup unit 3 is schematically shown for the sake of explanation.

As shown in FIG. 4, when the laser beam L is irradiated perpendicularly to the surface of the object W to be measured, the beam spot formed on the linear image sensor 32 is usually circular, and the light of the beam spot is formed. The intensities are normally distributed around the center of the circular shape. In this case, the light intensity distribution of the captured image is a normal distribution showing a peak at the center position of the beam spot.
However, as shown in FIGS. 5 to 9, the shape and light intensity distribution of the beam spot change depending on the state of the measurement site (for example, shape, material, etc.).

For example, as shown in FIG. 5, when the laser beam L irradiates the surface of the object W to be measured at an acute angle, the beam spot becomes elliptical, and the light intensity on one side of the ellipse becomes strong. In this case, the light intensity distribution becomes asymmetrical, and a peak appears at a position different from the center of the beam spot.

As shown in FIG. 6, when the measurement site of the measurement object W is an edge (left side in the figure), a shield (measurement object W) is placed on the optical path of the laser beam L reflected by the measurement site of the measurement object W. If there is another part) (center in the figure), or if the measurement part contains a boundary between parts with different luminosities in the object W to be measured (right side in the figure), the beam spot is chipped. The sharpness of the light intensity distribution increases.
As shown in FIG. 7, when the transparency of the object W to be measured is high, the dispersion rate of the light intensity of the beam spot becomes high, and the spread of the light intensity distribution becomes large.

FIG. 8 shows the measurement objects W having different reflectances with respect to the laser beam L. When the object W to be measured has a low level of reflectance (left side in the figure), the peak level of the light intensity distribution is smaller than when the object W to be measured has a medium level reflectance (center in the figure). .. On the other hand, when the object W to be measured has a high level of reflectance (right side in the figure), the light intensity of the beam spot exceeds the saturation level of the light receiving element, and the peak tip of the light intensity distribution becomes flat.

As shown in FIG. 9, when the laser beam L reflected at the measurement site of the measurement object W is further reflected at another site of the measurement object W and then incident on the linear image sensor 32, the linear image sensor 32 receives the laser light L. Two beam spots are formed and two peaks appear in the light intensity distribution.

When the light intensity distribution is deformed as shown in FIGS. 5 to 9, it becomes difficult to accurately detect the peak and the center of gravity, and the measurement error regarding the distance to the measurement site becomes large. As a result, in the shape measurement data of the measurement object W, the coordinate data corresponding to the measurement site becomes noise.

(Parameter)
Therefore, in the present embodiment, the degree of deformation of the light intensity distribution of the captured image is quantified by the first to fifth parameters (skewness, kurtosis, variance, peak level and number of peaks), and each of the first to fifth parameters is quantified. By using the captured image that satisfies the filter condition as valid data, data that may cause noise is removed from the shape measurement data.

Hereinafter, each parameter will be described with reference to FIGS. 10 to 14. In the following description, the number of pixels indicating a light intensity equal to or higher than a predetermined threshold in the captured image is defined as the number of data n, and the light intensity indicated by each pixel is the value Xi (i = 1, 2, ... N) of each data. ), The average value of the values Xi of each data is μ, and the standard deviation is σ.

歪度が０のとき、光強度分布は左右対称であり、そのピークは左右中央に位置している（図１０の中央参照）。一方、歪度が正のときピークが左側に偏っており（図１０の左側参照）、歪度が負のときピークが右側に偏っている（図１０の右側参照）。
歪度に関してフィルタ条件を設定する場合、例えば「０を含む任意の数値範囲」をフィルタ条件に設定できる。 FIG. 10 is a diagram for explaining the skewness, which is the first parameter representing the degree of deformation of the light intensity distribution. In FIG. 10, the center of the left and right shows the light intensity distribution when the skewness is 0, the left side shows the light intensity distribution when the skewness is larger, and the right side shows the light when the skewness is smaller than 0. It shows the intensity distribution. This skewness is a value representing the degree of distortion of the light intensity distribution, and can be obtained by, for example, the following equation (1).

When the skewness is 0, the light intensity distribution is symmetrical and the peak is located in the center of the left and right (see the center of FIG. 10). On the other hand, when the skewness is positive, the peak is biased to the left side (see the left side of FIG. 10), and when the skewness is negative, the peak is biased to the right side (see the right side of FIG. 10).
When setting the filter condition with respect to the skewness, for example, "any numerical range including 0" can be set as the filter condition.

尖度が３のとき光強度分布は正規分布しており、尖度が３より小さいとき光強度分布は尖っており、尖度が３より大きいとき光強度分布は扁平である。
尖度に関してフィルタ条件を設定する場合、例えば「３を含む任意の数値範囲」をフィルタ条件に設定できる。 FIG. 11 is a diagram illustrating kurtosis, which is a second parameter representing the degree of deformation of the light intensity distribution. The kurtosis is a value representing the degree of sharpness of the light intensity distribution, and can be obtained by, for example, the following equation (2).

When the kurtosis is 3, the light intensity distribution is normally distributed, when the kurtosis is smaller than 3, the light intensity distribution is sharp, and when the kurtosis is larger than 3, the light intensity distribution is flat.
When setting the filter condition for the kurtosis, for example, "any numerical range including 3" can be set as the filter condition.

光強度分布のばらつきが大きいほど、分散が大きくなる。この分散に関してフィルタ条件を設定する場合、例えば「最小値を０とした任意の数値範囲」をフィルタ条件に設定できる。 FIG. 12 is a diagram illustrating dispersion, which is a third parameter representing the degree of deformation of the light intensity distribution. The variance is a value representing the degree of variation in the light intensity distribution, and can be obtained, for example, by the following equation (3).

The greater the variation in the light intensity distribution, the greater the dispersion. When setting the filter condition for this variance, for example, "arbitrary numerical range with the minimum value as 0" can be set as the filter condition.

FIG. 13 is a diagram illustrating a peak level, which is a fourth parameter representing the degree of deformation of the light intensity distribution. This peak level represents the peak value of the light intensity distribution.
When setting the filter condition for the peak level, any numerical range can be set for the filter condition. The numerical range is preferably set to a range lower than the saturation level Vt.

FIG. 14 is a diagram illustrating the number of peaks, which is the fifth parameter representing the degree of deformation of the light intensity distribution. This number of peaks represents the number of peaks appearing in the light intensity distribution, and FIG. 14 illustrates the case where the number of peaks is 2.
When setting the filter condition for the number of peaks, it is preferable to set the numerical value "1" in the filter condition, for example.

(Shape measurement method)
First, the user inputs setting information for setting each filter information of the first to fifth parameters on the setting screen 9 as shown in FIG.
The setting screen 9 illustrated in FIG. 3 has a selection check box 91, a numerical adjustment bar 92, and a numerical input box 93 for each of the first to fifth parameters (skewness, kurtosis, variance, peak level, and number of peaks). Is displayed.
For example, the user can select a parameter for setting a filter condition by checking the selection check box 91. Further, the user adjusts the knob position with respect to the numerical value adjustment bar 92, or inputs a numerical value to the numerical value input box 93 to set an arbitrary numerical value or a numerical value range for the filter condition of the selected parameter. be able to.
The minimum and maximum values can be set for the first to fourth parameters (skewness, kurtosis, variance, peak level), that is, the numerical range can be set, and the fifth parameter (number of peaks) can be set. , The maximum value can be set (usually set to "1").

Further, on the setting screen 9 illustrated in FIG. 3, an average check box 94 is displayed for each of the first to fourth parameters (skewness, kurtosis, variance, and peak level). The user can set the filter condition of the parameter to the average range of the measurement result by checking the average check box 94 of any parameter.
As described above, the filter conditions are set for any of the first to fifth parameters.

In the coordinate measuring machine 1, the irradiation unit 2 scans the laser beam L on the measurement object W, and the image pickup unit 3 images each measurement portion of the measurement object W.
After the scanning of the measurement object W is completed, the determination unit 46 calculates the first to fifth parameters for each captured image acquired by the image acquisition unit 43. Further, the determination unit 46 determines the parameter in which the filter condition is set among the first to fifth parameters, and determines whether or not each parameter satisfies the filter condition for each captured image. Then, the determination unit 46 determines that the captured image in which each parameter satisfies the filter condition is valid data, and determines that the captured image in which the parameter that does not satisfy the filter condition exists is invalid data (determination step).
The shape measurement unit 44 generates shape measurement data based on the captured image determined to be valid data by the determination unit 46 among the plurality of captured images acquired by the image acquisition unit 43 (shape measurement step). ..

After that, when the user inputs the setting information to the setting screen 9, the condition setting unit 45 updates the filter condition of each parameter based on the setting information. Then, the determination unit 46 redetermines each captured image based on the updated filter conditions of each parameter, and updates the valid data. The shape measurement unit 44 regenerates the shape measurement data of the measurement target W based on the updated valid data.
The user can repeatedly change the filter conditions of each parameter until the noise is removed while checking the shape measurement data graphically displayed on the display unit 7.

[Effect of this embodiment]
In the coordinate measuring machine 1 of the present embodiment, among the captured images captured by the imaging unit 3, the captured image (pixel string) showing the light intensity distribution in which each parameter does not satisfy the filter condition is data that can generate noise. Is excluded from valid data. On the other hand, among the captured images captured by the imaging unit 3, the captured image (pixel string) showing the light intensity distribution in which each parameter satisfies the filter condition is the shape measurement data of the measurement target W as reliable effective data. Is used to generate.
That is, in the coordinate measuring machine 1 of the present embodiment, the captured image data for generating the shape measurement data of the object to be measured is selected based on the reliability. Therefore, it is possible to suppress the generation of noise in the shape generation data.

Here, a case where a spherical measurement object W1 is spherically measured will be described as an example.
When the spherical measurement object W1 is spherically measured, as shown in FIG. 15, the measurement portion irradiated with the laser beam L and the image pickup unit 3 face each other, and the reflected light reflected by the measurement portion is the image pickup unit 3. May be incident on. At this time, the feedback control of the light source control unit 41 cannot keep up with the change in the amount of light received, and the linear image sensor 32 receives the amount of light exceeding the saturation level. As a result, the light intensity of the captured image is saturated, and the distance to the measurement site calculated by the shape measuring unit 44 includes a large error.

In the above case, if the filter condition is not set, the coordinate data (noise) largely deviated from the spherical shape appears in the shape measurement data of the measurement object W1.
On the other hand, in the present embodiment, by setting the filter conditions for each parameter (particularly the peak level), the captured image in which the light intensity is saturated is excluded from the valid data. As a result, it is possible to generate shape measurement data from which the above-mentioned noise has been removed.

Further, a case where the shape of the measurement object W2 including the edge is measured will be described as an example.
As shown in FIG. 16, when the object to be measured W2 has a first surface 101 and a second surface 102 forming an edge, the angle formed between the first surface 101 and the optical axis of the laser beam L is determined. It is smaller than the angle formed between the second surface 102 and the optical axis of the laser beam L. In such a case, the distance between the laser spots S formed on the first surface 101 is smaller than the distance between the laser spots S formed on the second surface 102, and the measurement accuracy when the first surface 101 is measured is high. , It is lower than the measurement accuracy when the second surface 102 is measured.

Therefore, in the present embodiment, by setting filter conditions for a parameter (particularly skewness) indicating the degree of deformation of the light intensity distribution of the captured image, the captured image captured on the second surface 102 is used as valid data, while the first image is used. The captured image obtained by capturing the image of one surface 101 can be excluded from the valid data. As a result, only the data portion having low measurement accuracy is removed as noise from the shape measurement data of the object to be measured W2, and the accuracy of the shape measurement data can be improved.

In the shape measurement method of the prior art, each coordinate data constituting the shape measurement data is compared with the front and rear coordinate data, and the coordinate data significantly different from the front and back coordinate data is processed as noise. On the other hand, in the shape measuring method of the present embodiment, noise can be reduced by simpler processing without performing comparison processing with the data before and after as in the prior art.

[Modification example]
The present invention is not limited to each of the above embodiments, and modifications, improvements, and the like to the extent that the object of the present invention can be achieved are included in the present invention.

In the above embodiment, the flying spot type coordinate measuring machine 1 is described, but the present invention can also be applied to the line type coordinate measuring machine 1.
In the line-type coordinate measuring machine, the irradiation unit is not provided with a scanning mirror on the irradiation side, but is provided with a cylindrical lens or the like that forms a point-shaped laser beam L emitted from a light source into a line-shaped laser beam L. Further, the image pickup unit does not include a light receiving side scanning mirror and has an area image sensor instead of the line image sensor. The line-shaped laser beam L reflected by the measurement object W is imaged by the image pickup unit, and shape measurement data of the measurement object is generated based on the captured image.
In such a line-type coordinate measuring machine, one row or one row of continuous pixels of a captured image, which is a two-dimensional image, corresponds to the pixel row of the present invention, and each pixel row of the captured image corresponds to the pixel row of the embodiment. The same processing as that for the captured image can be performed. That is, it is possible to make a determination based on the light intensity distribution for each pixel sequence of the captured image and generate shape measurement data of the object to be measured based on the pixel sequence determined that each parameter satisfies the filter condition.

In the above embodiment, it is described that each parameter of skewness, kurtosis, variance, peak level, and number of peaks is calculated, but in the present invention, at least the filter condition (numerical condition) is set. Any one of the parameters may be calculated.

In the above embodiment, the captured image in which each parameter does not satisfy the filter condition is still stored in the storage unit 5 as invalid data, but may be deleted from the storage unit 5.
Further, in the above embodiment, the coordinate measuring machine 1 includes the probe unit 10 and the control unit 4, and the data processing device of the present invention is configured as the control unit 4 for controlling the probe unit 10. The data processing device is not limited to this.
For example, the data processing device of the present invention may be configured as a device different from the device having the probe unit 10, for example, a PC (Personal Computer). In this case, the data processing apparatus of the present invention at least functions as the image acquisition unit 43 and the shape measurement unit 44 in the embodiment by reading and executing the data processing program. Further, the data processing device may further function as the condition setting unit 45, the determination unit 46, and the display control unit 47 in the embodiment.
In such a case, the data processing apparatus of the present invention may acquire the captured image output from the probe unit 10 via a wired, wireless, recording medium, or the like, and perform each processing based on the captured image.

1 ... 3D measuring machine, 10 ... Probe unit, 2 ... Irradiation unit, 21 ... Light source, 22 ... Light source drive unit, 23 ... Irradiation optical system, 3 ... Imaging unit, 31 ... Light receiving optical system, 32 ... Linear image sensor, 33 ... Signal processing unit, 4 ... Control unit (data processing device), 41 ... Light source control unit, 42 ... Scan control unit, 43 ... Image acquisition unit, 44 ... Shape measurement unit, 45 ... Condition setting unit, 46 ... Judgment unit , 47 ... Display control unit, 5 ... Storage unit, 6 ... Operation unit, 7 ... Display unit, L ... Laser light, W, W1, W2 ... Measurement target.

Claims (4)

An irradiation unit that irradiates the object to be measured with laser light,
An imaging unit that captures the laser beam reflected by the measurement object and generates an captured image including one or more pixels.
A determination unit that calculates a parameter that quantifies the degree of change of the light intensity distribution indicated by the pixel sequence based on a normal distribution, and determines whether or not the calculated parameter satisfies a predetermined numerical value.
A shape measuring unit that generates shape measurement data of the object to be measured based on the pixel sequence showing the light intensity distribution for which the parameter is determined to satisfy the numerical condition.
A three-dimensional measuring machine characterized by being equipped with. In the three-dimensional measuring machine according to claim 1,
The determination unit calculates one or more parameters that are at least one of skewness, kurtosis, variance, peak level, and number of peaks for the light intensity distribution indicated by the pixel sequence, and the calculated parameters are calculated. A three-dimensional measuring machine characterized in that it determines whether or not the numerical value condition set for each of the parameters is satisfied. It is a shape measurement method performed based on an captured image including one or more rows of pixels acquired by imaging a laser beam reflected by a measurement object.
A determination step of calculating a parameter that quantifies the degree of change of the light intensity distribution indicated by the pixel sequence based on a normal distribution, and determining whether or not the calculated parameter satisfies a predetermined numerical value.
A tertiary step of generating shape measurement data of the object to be measured based on the pixel array showing the light intensity distribution for which the parameter is determined to satisfy the numerical condition. Former measuring machine. An image acquisition unit that acquires an image captured by a laser beam reflected by a measurement object and includes one or more pixel rows, and an image acquisition unit.
A determination unit that calculates a parameter that quantifies the degree of change of the light intensity distribution indicated by the pixel sequence based on a normal distribution, and determines whether or not the calculated parameter satisfies a predetermined numerical value.
A shape measuring unit that generates shape measurement data of the object to be measured based on the pixel sequence showing the light intensity distribution for which the parameter is determined to satisfy the numerical condition.
A data processing device characterized by comprising.

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