JP7028086B2 - Shape measuring device and shape measuring method - Google Patents

Description

The present invention relates to a shape measuring device and a shape measuring method for measuring the shape of an object to be measured by an optical cutting method.

The light cutting method is a method in which the reflected light of linear light irradiated to a relatively moving measurement object is imaged by an image pickup device, and the unevenness of the measurement object is measured from the degree of bending of the line reflected in the image. FIG. 5 shows a conventional shape measuring device 101 that measures the shape of an object to be measured by an optical cutting method. The shape measuring device 101 includes a linear light source 102 that irradiates linear light such as a line laser or slit light, and irradiates the measurement surface 100a of the conveyed measurement object 100 with linear light.

The shape measuring device 101 photographs the optical cutting line L1 formed on the measurement surface 100a of the measurement object 100 with the area camera 103, and the obtained captured image (also referred to as an optical cutting image) is transferred to the arithmetic processing device 104. Output. At this time, if the measurement surface 100a is flat, a linear optical cut line L1 appears in the captured image. However, when the measurement surface 100a has irregularities, a curved optical cut line L1 can be obtained. In this way, a method of measuring unevenness in the irradiation cross section based on the degree of bending of the light cutting line L1 is called a light cutting method.

In the optical cutting method, the object to be measured 100 and the linear light source 102 and the area camera 103 are relatively moved. However, in a manufacturing process such as steel, for example, a product having a non-uniform size on a fixed transport line. (For example, the measurement object 100 having a thickness variation or a width variation) may move. Further, as shown in FIG. 6A, while the measurement object 100 is being conveyed, the width center of the measurement object 100 may be deviated from the center in the width direction of the transfer line, and the measurement object 100 may be skewed. ..

Patent Document 1 proposes, for example, a method of automatically correcting the focus shift that occurs in the lens of the area camera 103 when the size of the measurement object 100 fluctuates or the measurement object 100 is skewed. is doing. Further, Patent Document 2 discloses that a frame is provided around the frame, and when an object to be photographed is placed on the frame, the frame is zoomed out to prevent the field of view from being out of sight. Further, Patent Document 3 discloses a configuration in which a swivel table on which a monitoring camera is installed is rotated when a tracking target object moves.

International Publication No. 2016/171265 Japanese Unexamined Patent Publication No. 2013-9435 Japanese Patent No. 3960758

However, in Patent Document 1, it is necessary that the optical cut line L1 is within the imaging field of view of the area camera 103. Therefore, as shown in FIG. 6B, for example, the measurement object 100 deformed in a curved shape is transported, or the measurement object 100 is greatly skewed, and the optical cut line L1 protrudes from the imaging field of view. In this case (hereinafter, also referred to as out-of-field of view), there is a problem that not only the focus correction cannot be performed but also the surface shape of the measurement surface 100a cannot be measured based on the optical cut line L1.

Further, in Patent Document 2, there is a problem that it cannot be applied to the shape measurement of the measurement surface 100a because the spatial resolution changes for each frame by zooming out. Further, in Patent Document 3, since it is difficult to rotate the swivel table at high speed, when the measurement object 100 moves at high speed on the transport line, the swivel table is subject to sudden size fluctuations and skews of the measurement object 100. Is difficult to follow. Therefore, even in Patent Document 3, there is a problem that the optical cutting line L1 is out of the field of view, and the surface shape of the measurement surface 100a cannot be measured based on the optical cutting line L1.

The present invention has been made in view of the above problems, and provides a shape measuring device and a shape measuring method capable of measuring the surface shape of a measurement object based on an optical cutting line more reliably than before. With the goal.

The shape measuring device of the present invention is a shape measuring device for measuring the shape of the measuring surface of an object to be measured, in which a linear light source that irradiates the measuring surface with linear light and light on the measuring surface by the linear light. A first imaging unit that captures a predetermined region including a cutting line and extracts a part of the acquired image as an optical cutting line extraction image, and at least an imaging region of the optical cutting line extraction image, and the light The surface shape of the object to be measured is calculated based on the second imaging unit that acquires a wide area image captured by imaging the area of the measurement surface that is wider than the image area of the cut line extracted image, and the optical cut line extracted image. It has an arithmetic processing apparatus, and the arithmetic processing apparatus includes an optical cutting line position measuring unit for measuring an optical cutting line position from the wide area captured image, and the first imaging unit from the inside of the optical cutting line extracted image. When the optical cutting line deviates, the extraction position for extracting the optical cutting line extraction image from the captured image is set to the extraction position where the optical cutting line is included in the optical cutting line extraction image based on the optical cutting line position. It is provided with an imaging field control unit that can be changed to.

Further, the shape measuring device of the present invention is a shape measuring device for measuring the shape of the measuring surface of an object to be measured, in which a linear light source that irradiates the measuring surface with linear light and the measuring surface by the linear light. A first imaging unit that captures a predetermined region including the optical cut line and extracts a part of the acquired image as an optical cut line extraction image, and at least an imaging region of the optical cut line extraction image, and A second image pickup unit that acquires a wide area image captured by imaging a region of the measurement surface that is wider than the image area of the light cut line extracted image, and a surface shape of the object to be measured based on the light cut line extracted image. The arithmetic processing apparatus has an arithmetic processing apparatus for calculating, and the arithmetic processing apparatus has an optical cutting line position measuring unit for measuring an optical cutting line position from the wide area captured image, and a first imaging unit for focusing on the optical cutting line. When it deviates, it is provided with a focus adjusting unit for changing the focus position of the first imaging unit to a focus position in which the light cutting line is in focus based on the light cutting line position.

Further, the shape measuring device of the present invention is a shape measuring device for measuring the shape of the measuring surface of an object to be measured, in which a linear light source that irradiates the measuring surface with linear light and the measuring surface by the linear light. A first imaging unit that captures a predetermined region including the optical cut line and extracts a part of the acquired image as an optical cut line extraction image, and at least an imaging region of the optical cut line extraction image, and A second image pickup unit that acquires a wide area image captured by imaging a region of the measurement surface that is wider than the image area of the light cut line extracted image, and a surface shape of the object to be measured based on the light cut line extracted image. It has an arithmetic processing device for calculating, and the arithmetic processing apparatus includes an optical cutting line position measuring unit for measuring the optical cutting line position from the wide area captured image, and the optical cutting line extracted image in the first imaging unit. When the optical cutting line deviates from the above, the optical cutting line is included in the optical cutting line extraction image based on the optical cutting line extraction position at which the optical cutting line extraction image is extracted from the captured image. When the imaging field control unit that changes the extraction position and the first imaging unit are out of focus on the optical cutting line, the focus position of the first imaging unit is set to the optical cutting line based on the optical cutting line position. It is provided with a focus adjusting unit for changing the focus position to the focus position.

The shape measuring method of the present invention is a shape measuring method for measuring the shape of the measuring surface of an object to be measured, wherein the measuring surface is irradiated with linear light, and the first imaging unit is used to obtain the linear light. It includes a first imaging step of imaging a predetermined region including a light cut line on a measurement surface and extracting a part of the acquired image as an optical cut line extraction image, and at least an imaging region of the optical cut line extraction image. Based on the second imaging step of acquiring a wide-area image captured by the second imaging unit, which is an image of a region of the measurement surface wider than the image area of the optical cut line extracted image, and the optical cut line extracted image. The calculation processing step includes an arithmetic processing step for calculating the surface shape of the object to be measured, and the arithmetic processing step includes an optical cutting line position measuring step for measuring the optical cutting line position from the wide area captured image, and the first imaging. When the optical cutting line deviates from the light cutting line extraction image in the unit, the extraction position for extracting the optical cutting line extraction image from the captured image is determined based on the optical cutting line position, and the optical cutting line extraction image is obtained. It is provided with an imaging field control step for changing to an extraction position including the optical cutting line.

Further, the shape measuring method of the present invention is a shape measuring method for measuring the shape of the measuring surface of a measurement object, wherein the linear light is irradiated by an irradiation step of irradiating the measuring surface with linear light and a first imaging unit. The first imaging step of imaging a predetermined region including the optical cut line on the measurement surface and extracting a part of the acquired image as an optical cut line extracted image, and at least the imaging region of the optical cut line extracted image. A second imaging step of acquiring a wide-area image captured by the second imaging unit, which includes the image of a region of the measurement surface that is wider than the image area of the optical cut line extracted image, and the optical cut line extracted image. The calculation processing step includes an arithmetic processing step for calculating the surface shape of the object to be measured based on the above, and the arithmetic processing step includes an optical cutting line position measuring step for measuring the optical cutting line position from the wide area captured image, and the first. 1 When the image pickup unit is out of focus on the light cut line, the focus adjustment step of changing the focus position of the first image pickup unit to a focus position in which the light cut line is in focus based on the light cut line position. , Is provided.

Further, the shape measuring method of the present invention is a shape measuring method for measuring the shape of the measuring surface of a measurement object, wherein the linear light is irradiated by an irradiation step of irradiating the measuring surface with linear light and a first imaging unit. The first imaging step of imaging a predetermined region including the optical cut line on the measurement surface and extracting a part of the acquired image as an optical cut line extracted image, and at least the imaging region of the optical cut line extracted image. A second imaging step of acquiring a wide-area image captured by the second imaging unit, which includes the image of a region of the measurement surface that is wider than the image area of the optical cut line extracted image, and the optical cut line extracted image. The calculation processing step includes an arithmetic processing step for calculating the surface shape of the object to be measured based on the above, and the arithmetic processing step includes an optical cutting line position measuring step for measuring the optical cutting line position from the wide area captured image, and the first. When the optical cut line deviates from the inside of the optical cut line extracted image in the imaging unit, the extraction position for extracting the optical cut line extracted image from the captured image is set based on the optical cut line position. When the image pickup field control step of changing the extraction position to include the light cut line in the extracted image and the focus position of the first image pickup unit are out of focus by the first image pickup unit, the focus position of the first image pickup unit is changed to the light. It includes a focus adjustment step for changing to a focus position in which the optical cutting line is in focus based on the cutting line position.

According to the present invention, the extraction position of the optical cut line extracted image extracted from the captured image is changed by the first imaging unit based on the position of the optical cut line included in the wide area captured image. , It is possible to prevent the optical cut line from being out of the field of view from the extracted image. Thus, in the present invention, the surface shape of the object to be measured can be measured more reliably than before based on the optical cut line.

Further, according to the present invention, the focus position of the first image pickup unit is changed based on the position of the light cut line included in the wide area captured image, so that the light cut line in the first image pickup unit is changed. You can prevent out of focus. Thus, in the present invention, the surface shape of the object to be measured can be measured more reliably than before based on the optical cut line.

It is a schematic diagram which shows the structure of the shape measuring apparatus of this invention. FIG. 2A is a schematic view showing a light cut line on the measurement surface, and FIG. 2B is a graph showing a projection waveform in which the position of the light cut line appears as a peak. It is a flowchart which shows the shape measurement processing procedure by this invention. It is a flowchart which shows the shape measurement processing procedure by another embodiment. It is a schematic diagram provided for the explanation of the optical cutting method. FIG. 6A is a schematic diagram for explaining when the object to be measured is skewed, and FIG. 6B is a schematic diagram for explaining when the optical cut line is out of the field of view.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. In the following description, similar elements are designated by the same reference numerals, and duplicate description will be omitted.

<About the shape measuring device of the present invention>
FIG. 1 is a schematic view showing the configuration of the shape measuring device 1 according to the present invention. The shape measuring device 1 images the measurement surface 100a of the measurement object 100 transported in the transport direction D along the transport line, and extracts a part of the region ER1 as an optical cut line extraction image from the obtained captured image. .. Here, the optical cut line extraction image is obtained by extracting only the periphery of the region in which the optical cut line L1 is captured from the captured image as a region of interest (hereinafter referred to as ROI: Region of interest), and hereinafter, the ROI image. Also called.

The shape measuring device 1 measures the surface shape of the measuring surface 100a by performing image processing on the ROI image. The shape measuring device 1 includes a linear light source 6, an image pickup device 2, an arithmetic processing device 3, a storage unit 4, and a display device 5, and these configurations will be described in order below.

The linear light source 6 is composed of a known light source such as a laser or an LED, and irradiates the measurement surface 100a of the measurement object 100 with the linear light L. A linear bright portion (light cut line) L1 is formed at a portion of the measurement surface 100a of the measurement object 100 irradiated with the linear light L. The reflected light from the optical cut line L1 is imaged by the image pickup apparatus 2. The image pickup apparatus 2 includes a first image pickup unit 11a that generates an ROI image, a second image pickup unit 11b that acquires a wide area image pickup image that includes an image pickup area of the ROI image and has a wider area ER2 than the ROI image, and a second image pickup unit 11b. 1 It has a focus adjustment motor 12 for adjusting the focus of the image pickup unit 11a.

The first image pickup unit 11a is, for example, an area camera, first captures a predetermined region of the measurement surface 100a on which the optical cut line L1 is formed, and internally acquires an image captured by exposing all the pixels of the entire imaging field of view. .. After that, the first image pickup unit 11a reads out only the pixels in the partial region ER1 including the optical cut line L1 from the acquired captured images, and extracts them as an ROI image.

Here, the captured image includes not only the form as a concrete image displayed on the display but also the captured data before being generated as an image. Therefore, without forming the imaging data in which all the pixels of the entire imaging field are exposed as a concrete image, only the portion corresponding to the pixels in the partial area ER1 is out of the data of all the pixels acquired by the exposure. Can also be read out and directly converted into a ROI image.

In this way, the first imaging unit 11a extracts the ROI image that captures the periphery of the optical cut line L1 from the captured image in which all the pixels of the entire imaging field are exposed, so that the amount of data is reduced as compared with the captured image. Generate a ROI image. The first imaging unit 11a acquires captured images at predetermined intervals while the measurement object 100 is being conveyed, obtains an ROI image each time a captured image is obtained, and transfers the ROI image to the arithmetic processing device 3. Send in sequence.

Here, when the object to be measured 100 is transported at high speed or when the shape is measured at high density by shortening the imaging interval, a high frame rate is required, but it can be obtained by the first imaging unit 11a. In the full frame (the image captured by the entire image pickup field of the first image pickup unit 11a), the amount of transmission data is large, and a sufficient frame rate cannot be obtained due to the limitation of the upper limit of the transmittable amount per unit time. Therefore, it is not preferable to use a full frame in the first imaging unit 11a to widen the field of view in order to prevent the optical cut line L1 from deviating from the field of view.

Therefore, it is desirable to increase the image transmission speed by extracting only a part of the region ER1 in which the optical cut line L1 is captured from the entire imaging field of view of the first imaging unit 11a, instead of dealing with the full frame. .. However, the smaller the ROI image that extracts the partial region ER1 in which the optical cut line L1 is captured, the higher the possibility that the optical cut line L1 is out of the field of view.

Therefore, in the shape measuring device 1 according to the present invention, in addition to the first imaging unit 11a that generates the ROI image, a second imaging unit 11b that images a region on the measurement surface 100a that is wider than the ROI image is provided. .. Here, the first imaging unit 11a generates an ROI image for measuring the unevenness of the measurement surface 100a from the bending condition of the optical cutting line L1 as in the conventional case. On the other hand, the second imaging unit 11b images the measurement surface 100a in order to measure the position of the optical cut line L1 (hereinafter, referred to as the optical cut line position) that fluctuates on the measurement surface 100a.

The second imaging unit 11b acquires a wide-area captured image that includes an imaging region of the ROI image and captures a region of the measurement surface 100a that is wider than the imaging region of the ROI image. As a result, the second imaging unit 11b can acquire a wide-area image taken by capturing the optical cutting line L1 on the measurement surface 100a even when the optical cutting line L1 is removed from the ROI image. Therefore, the second imaging unit 11b can image the optical cut line L1 on the measurement surface 100a even if the position of the optical cut line changes due to the size change of the measurement object 100 or the skew of the measurement object 100. Is set.

The second image pickup unit 11b acquires wide-area captured images at predetermined intervals while the measurement object 100 is being conveyed, and sequentially sends them to the arithmetic processing unit 3. Here, the wide-area captured image has at least a lower resolution or a lower image quality than the captured image acquired by the first imaging unit 11a, and the amount of data is smaller than that of the captured image. It is preferable to use a wide-area image with low resolution or low image quality so that the amount of data in the wide-area image is the same as that of the ROI image. As a result, the data transfer speed from the second image pickup unit 11b to the arithmetic processing unit 3 can be increased, and the arithmetic processing unit 3 can acquire a wide-area captured image at an acquisition timing equivalent to the acquisition timing of the ROI image. be.

Further, the second image pickup unit 11b does not simply reduce the resolution or image quality, but may perform imaging by lowering the frame rate to the extent that the time interval in which the size fluctuation or skew occurs in advance is not exceeded. good.

In the shape measuring device 1 according to the present invention, the position of the optical cut line in the wide area captured image obtained by the second image pickup unit 11b is measured by the arithmetic processing device 3, and the first image pickup unit 11a is based on the optical cut line position. Adjust the extraction position of the ROI image to be extracted from the captured image with. As a result, the shape measuring device 1 can prevent the optical cut line L1 from being out of the field of view from the ROI image while enabling high-speed imaging with the ROI image.

In this case, the arithmetic processing unit 3 has a first image acquisition unit 14a that receives an ROI image from the first image pickup unit 11a, and a second image acquisition unit 14b that receives a wide area captured image from the second image pickup unit 11b. The first image acquisition unit 14a sends the ROI image sequentially input from the first image pickup unit 11a to the image pickup field control unit 15 and the shape measurement unit 17.

The shape measuring unit 17 calculates the uneven shape of the measurement surface 100a of the measurement object 100 based on the bending condition of the optical cutting line L1 existing in the ROI image. When the measurement surface 100a is a flat surface without unevenness, a linear optical cut line L1 appears in the ROI image. On the other hand, for example, when the measurement surface 100a has a convex shape, a curved portion generated by the convex shape of the measurement surface 100a appears on the optical cut line L1 in the ROI image.

Since the calculation process for calculating the uneven shape of the measurement surface 100a by the shape measuring unit 17 is the same as that of International Publication No. 2016/171265, the description thereof is omitted here, but for example, International Publication No. 2016/171265. As shown in No. 17, the shape measuring unit 17 specifies the horizontal position where the maximum brightness is obtained at each position in the vertical direction of the ROI image, obtains the curved portion of the optical cutting line L1, and obtains the uneven shape of the measurement surface 100a. Is calculated.

The shape measuring unit 17 sends the calculated shape of the measurement surface 100a as a shape image to the storage unit 4 and the display device 5. The storage unit 4 stores the shape image received from the shape measurement unit 17, and the display device 5 displays the shape image received from the shape measurement unit 17. The display device 5 can notify the operator of the presence or absence of unevenness of the measurement surface 100a by displaying the shape image of the measurement surface 100a. By storing the shape image of the measurement surface 100a, the storage unit 4 can specify, for example, a position having an uneven shape on the measurement surface 100a.

On the other hand, the second image acquisition unit 14b sends the wide area image captured image sequentially input from the second image pickup unit 11b to the optical cut line position measurement unit 16. The optical cut line position measuring unit 16 measures the optical cut line position in the wide area captured image. Here, FIG. 2A is an example of a wide-area image capture image A in which the measurement surface 100a is imaged by the second image pickup unit 11b.

In the wide area captured image A, the transport direction of the measurement object 100 is the X direction, and the extension direction of the optical cutting line L1 orthogonal to the X direction is the Y direction. The wide area captured image A is, for example, an image I (x, y) of N × M pixels (0 ≦ x ≦ N-1, 0 ≦ y ≦ M-1). Here, x is the position in the X direction of each pixel, and y indicates the position in the Y direction of each pixel.

Based on the following formula (1), the optical cutting line position measuring unit 16 extends the optical cutting line L1 in the horizontal direction (X direction) of the wide area captured image A in FIG. 2A (longitudinal direction, Y direction). The sum of the brightness values of the pixels arranged in the line (cumulative brightness value) is taken, and a waveform representing the cumulative brightness value at each position in the horizontal direction as shown in FIG. 2B (hereinafter referred to as a projection waveform) is calculated.

Here, the position of the optical cut line appears in the wide area captured image A with a luminance value different from that of the portion not irradiated with the optical cut line L1. Therefore, even in the projection waveform, the cumulative luminance value at the position where the optical cutting line L1 is irradiated is significantly higher than the cumulative luminance value at other positions where the optical cutting line L1 is not irradiated, and as a peak. appear. For example, as shown in FIG. 2A, since the optical cutting line L1 extends in the vertical direction, the position of the optical cutting line L1 appears as a peak in the projection waveform as shown in FIG. 2B. The optical cutting line position measuring unit 16 measures the position where the cumulative luminance value is remarkably high in the calculated projection waveform as the optical cutting line position.

The optical cut line position may be, for example, the peak position of the projection waveform as shown in the following equation (2), or the center of gravity position of the projection waveform as shown in the following equation (3). Since it is sufficient that the rough position of the optical cut line L1 can be specified from the wide-area captured image, the wide-area captured image can be reduced in resolution and image quality.

In the wide area captured image A shown in FIG. 2A, an optical cut line L1 formed by a straight line portion La and a curved portion Lb generated by the convex shape of the measurement surface 100a appears. As shown in FIG. 1, the optical cutting line position measuring unit 16 sends the measured optical cutting line position as optical cutting line position data to the imaging field control unit 15 and the focus adjusting unit 18. As shown in FIG. 2A, the optical cut line position data is X coordinate data indicating the position of the optical cut line L1 in the horizontal direction (X direction) of the wide area captured image A.

Here, the storage unit 4 shows the positional relationship between the position in the captured image acquired by the first image pickup unit 11a and the position in the wide area captured image acquired by the second image pickup unit 11b. The position information is stored in advance. When the imaging field control unit 15 receives the optical cutting line position data, the imaging field control unit 15 refers to the corresponding position information, and the optical cutting line position measured from the wide area captured image by the optical cutting line position measuring unit 16 is determined by the first imaging unit 11a. Convert to the position in the acquired captured image.

In this way, the image pickup field control unit 15 indicates the optical cut line position indicated by the position in the wide area image capture image as the position in the image capture image, and uses this as the extraction position data as the first image acquisition unit 14a. Is sent to the first image pickup unit 11a via the above. As a result, the first imaging unit 11a changes the extraction position of the ROI image to be extracted from the captured image based on the extraction position data, and extracts the ROI image from the captured image. In the case of this embodiment, the first image pickup unit 11a includes, for example, an optical cut line L1 by extracting a predetermined region having the position of the extraction position data as a midpoint from the captured image as an ROI image. Generate a ROI image.

Thus, even if there is a possibility that the optical cut line L1 may deviate from the current ROI image due to the change in the position of the optical cut line in the captured image due to the size change of the measurement object 100 or the skew of the measurement object 100. The first imaging unit 11a extracts the ROI image by following the positional deviation of the optical cutting line L1 in the captured image based on the optical cutting line position in the wide area captured image acquired by the second imaging unit 11b. You can change the position. In this way, the first imaging unit 11a changes the extraction position from the captured image so that the optical cutting line L1 is always captured in the ROI image, and prevents the optical cutting line L1 from being out of the field of view from the ROI image. , The ROI image always including the optical cut line L1 can be continuously acquired.

In addition to this configuration, the storage unit 4 has the optical cut line position in the wide area captured image acquired by the second image pickup unit 11b and the optical cut line L1 at the optical cut line position in the wide area captured image. On the other hand, focusing correspondence information indicating the correspondence relationship with the focus position where the first image pickup unit 11a can focus is stored in advance. When the focus adjusting unit 18 receives the optical cut line position data, the focus adjusting unit 18 refers to the focusing correspondence information, and from the optical cut line position measured from the wide area captured image by the optical cut line position measuring unit 16, the first imaging unit 11a The focus position in which the light cut line L1 in the captured image is in focus is specified.

The focus adjustment unit 18 sends the focus position specified based on the focusing correspondence information to the focus adjustment motor 12 of the image pickup apparatus 2 as focus setting data. The focus adjustment motor 12 drives and controls the lens of the first image pickup unit 11a based on the focus setting data, and adjusts the focus position of the lens. As a result, the first image pickup unit 11a can always focus on the light cut line L1 in the captured image, and can capture the light cut line L1 finely and clearly in the ROI image extracted from the captured image. can.

The first image pickup unit 11a extracts the ROI image in which the optical cut line L1 is in focus in the captured image and the optical cut line L1 is captured from the captured image, and sends the ROI image to the arithmetic processing apparatus 3. Thus, even if the size of the measurement object 100 fluctuates or the measurement object 100 is skewed, the position of the optical cut line fluctuates in the captured image, and the optical cut line L1 may be out of focus in the ROI image. The first image pickup unit 11a can always focus on the optical cut line L1 in the ROI image based on the focus setting data. Therefore, in the arithmetic processing unit 3, the shape measuring unit 17 can accurately determine the bending condition of the optical cutting line L1 based on the ROI image, and can maintain the accuracy of the shape measurement even if the position of the optical cutting line fluctuates.

<Shape measurement process of the present invention>
Next, the above-mentioned shape measurement process executed by the shape measuring device 1 will be described with reference to the flowchart shown in FIG. As shown in FIG. 3, the shape measuring device 1 moves from the start step to step SP1 and step SP9. Here, steps SP1 to SP8 in FIG. 3 show processing related to the first imaging unit 11a, and steps SP9 to SP14 are processing related to the second imaging unit 11b.

Here, first, the processing related to the second imaging unit 11b will be described. In step SP9, when the shape measurement process is started, the shape measuring device 1 performs the initial setting of the second imaging unit 11b and moves to the next step SP10. Here, the second image pickup unit 11b sets, for example, the predicted position of the optical cut line L1 in the wide area captured image as an initial setting. Further, even if the position of the optical cut line fluctuates due to the size change of the measurement object 100, the skew of the measurement object 100, or the like, a sufficiently wide field of view is set so that the optical cut line L1 on the measurement surface 100a can be imaged. ..

In step SP10, when the object to be measured 100 is transported along the transport line, the process proceeds to step SP11. In step SP11, the arithmetic processing unit 3 acquires a wide-area image captured by capturing the measurement surface 100a from the second image pickup unit 11b, and moves to the next step SP12. In step SP12, the arithmetic processing unit 3 measures the optical cutting line position from the wide area captured image by the optical cutting line position measuring unit 16, and moves to the next step SP13.

In step SP13, when the imaging field control unit 15 receives the optical cutting line position measured by the optical cutting line position measuring unit 16 as the optical cutting line position data, the imaging field control unit 15 refers to the corresponding position information and corresponds to the optical cutting line position data. Identify the extraction position data. Further, in step SP13, when the focus adjusting unit 18 receives the optical cutting line position measured by the optical cutting line position measuring unit 16 as the optical cutting line position data, the focus adjusting unit 18 refers to the focus correspondence information and corresponds to the optical cutting line position data. Identify the focus setting data that has been set.

Next, in step SP14, the image pickup field control unit 15 sends the specified extraction position data to the first image pickup unit 11a, and the focus adjustment unit 18 sends the specified focus setting data to the first image pickup unit 11a. , The process again proceeds to step SP10 described above. In this way, steps SP11 to SP14 are repeated until a negative result is obtained in step SP10, that is, until the measurement object 100 is completely conveyed.

Next, the process relating to the first image pickup unit 11a will be described. In step SP1, when the shape measurement process is started, the shape measuring device 1 performs the initial setting of the first imaging unit 11a and moves to the next step SP2. Here, as initial settings, the first imaging unit 11a sets the initial extraction position for extracting the ROI image from the captured image and the optical cutting line L1 based on the predicted position of the optical cutting line L1 in the captured image, for example. Set the initial focus position to focus on.

The predicted position of the optical cut line L1 in the captured image used as the initial setting can be determined in advance from past operation data, higher-level information from the process computer (not shown), and the like.

In step SP2, when the object to be measured 100 is transported along the transport line, the process proceeds to step SP3. In step SP3, the first imaging unit 11a determines whether or not the extraction position data and the focus setting data have been received from the arithmetic processing unit 3. If an affirmative result is obtained in step SP3, this means that the extraction position data and the focus setting data have not been received from the arithmetic processing unit 3, and at this time, the first imaging unit 11a then goes to step SP6. Move.

On the other hand, when an affirmative result is obtained in step SP3, this means that the extraction position data and the focus setting data are received from the arithmetic processing device 3, that is, in the wide area captured image acquired by the second imaging unit 11b. It is shown that the extraction position data and the focus setting data are specified by the arithmetic processing apparatus 3 based on the optical cut line position. At this time, the first image pickup unit 11a moves to the next steps SP4 and SP5.

In step SP4, the first imaging unit 11a sets the extraction position for extracting the ROI image from the captured image based on the extraction position data received from the arithmetic processing device 3, and moves to the next step SP6. Further, in step SP5, the first imaging unit 11a drives and controls the lens based on the focus setting data received from the arithmetic processing unit 3, and sets the focus so that the optical cut line L1 in the ROI image is in focus. , Move to the next step SP6.

In step SP6, the first image pickup unit 11a takes an image of the measurement surface 100a of the measurement object 100, acquires an image in which the optical cut line L1 is captured on the measurement surface 100a, and moves to the next step SP7. In step SP7, the first imaging unit 11a focuses on the focus position set in step SP5, and extracts the ROI image from the captured image at the extraction position set in step SP4 to obtain the ROI image. The ROI image is sent to the arithmetic processing apparatus 3, and the process returns to step SP2 again. In this way, steps SP3 to SP7 are repeated until a negative result is obtained in step SP2, that is, until the measurement object 100 is completely conveyed.

When the measurement object 100 has been conveyed and a negative result is obtained in step SP2, the arithmetic processing unit 3 moves to the next step SP8. In step SP8, the arithmetic processing unit 3 calculates the surface shape of the measurement surface 100a from each ROI image acquired from the first image pickup unit 11a, sends the surface shape to the storage unit 4 and the display device 5, and has the above-mentioned shape. End the calculation process.

<Action and effect>
In the above configuration, the first image pickup unit 11a takes an image of a predetermined region including the optical cut line L1 on the measurement surface 100a by the first image pickup unit 11a, and extracts a part of the obtained image pickup image ER1 as an ROI image. do. The first image pickup unit 11a extracts the ROI image from the captured image each time the captured image is acquired, and sends only the ROI image to the arithmetic processing apparatus 3.

As described above, in the shape measuring device 1, the ROI image with a reduced amount of data is generated by the first imaging unit 11a, and the ROI image is transmitted to the arithmetic processing apparatus 3 from the first imaging unit 11a to the arithmetic processing apparatus 3. Data transfer speed can be increased. Therefore, the arithmetic processing device 3 can obtain a necessary and sufficient frame rate even when the measurement object 100 is conveyed at high speed or when the shape measurement is performed at high density by shortening the imaging interval. The surface shape of the measurement object 100 transported at high speed can be calculated based on the ROI image.

In addition, in the shape measuring device 1, the second image pickup unit 11b captures a wide area image captured by the area ER2 of the measurement surface 100a, which includes at least the image pickup area of the ROI image and is wider than the image pickup area of the ROI image. get. As a result, in the arithmetic processing apparatus 3, even if the optical cut line L1 is removed from the ROI image in the first image pickup unit 11a, the second image cut line is based on the position of the optical cut line in the wide area captured image acquired by the second image pickup unit 11b. 1 The extraction position of the ROI image in the captured image by the imaging unit 11a can be changed.

For example, even if the size of the measurement object 100 fluctuates or the measurement object 100 is skewed and the optical cut line L1 deviates significantly from the current ROI image, light is emitted from a wide area captured image having a wider imaging area than the ROI image. The position change of the cutting line L1 can be measured, and the extraction position of the ROI image can be changed according to the change of the optical cutting line position. As a result, the arithmetic processing unit 3 can always acquire the ROI image including the optical cut line L1 even if the ROI image having an extremely narrow imaging region is used. Therefore, the shape measuring device 1 can prevent the optical cut line L1 from being out of the field of view from the ROI image, and thus can measure the surface shape of the object to be measured 100 more reliably than before based on the optical cut line L1.

Further, in the arithmetic processing unit 3, even if the first image pickup unit 11a loses focus on the light cut line L1, the first image pickup unit 3 is based on the position of the light cut line in the wide area captured image acquired by the second image pickup unit 11b. The focus position of 11a can be changed.

For example, even if the size of the measurement object 100 fluctuates or the measurement object 100 is skewed, the position of the optical cutting line L1 in the current ROI image is changed, and the focus is greatly deviated from the optical cutting line L1. The focus position can be changed according to the change in the position of the optical cut line. As a result, the arithmetic processing unit 3 always acquires the ROI image in focus on the optical cutting line L1 even if the focus position shifts with respect to the optical cutting line L1 is likely to occur by using the ROI image having an extremely narrow imaging region. can. Therefore, the shape measuring device 1 can prevent the first imaging unit 11a from being out of focus with respect to the optical cutting line L1, and thus, the surface shape of the object to be measured 100 is measured more accurately than before based on the optical cutting line L1. can.

<Other embodiments>
In the above-described embodiment, both the extraction position data and the focus setting data are specified by the arithmetic processing device 3, the extraction position of the ROI image from the captured image, and the focus position with respect to the optical cut line L1 in the captured image. Although the shape measuring device 1 for simultaneously adjusting the above is described, the present invention is not limited to this, and the shape measuring device is such that the arithmetic processing device 3 specifies only one of the extraction position data and the focus setting data. You may.

Further, in the above-described embodiment, the first imaging unit 11a receives the extraction position data and the focus from the arithmetic processing device 3 without determining whether or not the optical cut line L1 is reflected in the current ROI image. The extraction position and the focus position of the ROI image are changed based on the setting data, but the present invention is not limited to this. For example, it is determined whether or not the optical cut line L1 is shown in the current ROI image, and only when the optical cut line L1 is not shown in the ROI image, the ROI image is based on the extraction position data and the focus setting data. You may change the extraction position and the focus position of.

Here, FIG. 4, which is shown by assigning the same reference numerals to the portions corresponding to those in FIG. 3, shows a flowchart of the shape measurement process according to another embodiment. The shape measurement process according to the other embodiment shown in FIG. 4 is different from the shape measurement process of FIG. 3 described above in that step SP15 is provided between step SP12 and step SP13. Hereinafter, the differences will be described.

In this case, in step SP12, when the optical cut line position measuring unit 16 calculates the optical cut line position from the wide area image captured image acquired from the second image pickup unit 11b, the process proceeds to the next step SP15. In step SP15, the optical cutting line position measuring unit 16 changes between the optical cutting line position before newly measuring the optical cutting line position in step SP12 and the optical cutting line position newly measured in step SP12 by a certain value or more. Determine if you are doing it.

In this case, as a constant value, when the optical cut line position before measuring the optical cut line position in step SP12 changes to the light cut line position newly measured in step SP12, the first image pickup unit 11a cuts light. The displacement amount is such that the line position is out of the ROI image or the light cut line L1 is out of focus.

Here, when an affirmative result is obtained in step SP15, this means that the optical cutting line position before measuring the optical cutting line position in step SP12 and the optical cutting line position newly measured in step SP12 are constant values. This indicates that the above changes, that is, the optical cut line position has changed so that the optical cut line position is out of the ROI image or the focus on the optical cut line L1 is out of focus. The cutting line position measuring unit 16 moves to the next step SP13.

In step SP13, the arithmetic processing unit 3 specifies the extraction position data and the focus setting data based on the optical cut line position in the wide area captured image acquired by the second imaging unit 11b, and steps in the same manner as in FIG. 3 described above. Execute SP13 or later.

On the other hand, if a negative result is obtained in step SP15, this means that the optical cut line position before measuring the optical cut line position in step SP12 and the optical cut line position newly measured in step SP12 are equal to or more than a certain value. It means that there is no change, that is, the displacement amount of the optical cutting line position is small, the optical cutting line position stays in the ROI image, and the optical cutting line L1 is also in focus. At this time, the optical cutting line is in focus. The line position measuring unit 16 returns to step SP10 again.

In this case, the arithmetic processing unit 3 does not newly specify the extraction position data and the focus setting data, and does not send the extraction position data and the focus setting data to the first imaging unit 11a. Since the negative result is obtained in step SP3, the first imaging unit 11a maintains the extraction position and the focus position of the ROI image extracted from the captured image as they are.

Here, when the optical cutting line position before measuring the optical cutting line position in step SP12 and the optical cutting line position newly measured in step SP12 change by a certain value or more, the extraction position data and the focus setting are set. The data is sent from the arithmetic processing apparatus 3 to the first imaging unit 11a, but the present invention is not limited to this.

For example, the displacement of the optical cutting line position may be determined by the first imaging unit 11a instead of being determined by the arithmetic processing unit 3. In this case, the first image pickup unit 11a receives the extraction position data and the focus setting data generated each time the second image pickup unit 11b acquires a wide area image pickup image, and the optical cut line position changes by a certain value or more. Judge whether or not.

When the first image pickup unit 11a determines that the optical cut line position changes by a certain value or more and the optical cut line position is out of the ROI image or the optical cut line L1 is out of focus, the arithmetic processing apparatus 3 The extraction position of the ROI image is changed and the focus position is changed based on the extraction position data and the focus setting data received from. Even in such an embodiment, the same effect as that of the above-described embodiment can be obtained.

Further, in the above-described embodiment, the position of the optical cut line in the wide-area captured image is measured based on the projection waveform as shown in FIG. 2B, but the present invention is not limited to this. The optical cut line position measuring unit 16 may, for example, binarize the wide area captured image and measure the optical cut line position based on the brightness in the wide area captured image.

Further, in the above-described embodiment, the measurement object 100 is conveyed and the image pickup apparatus 2 and the linear light source 6 are fixed, but the present invention is not limited to this, and for example, the measurement object 100 is stationary. The state may be set and the image pickup apparatus 2 and the linear light source 6 may be moved.

In the above-described embodiment, the optical cut line extraction image (ROI image) and the wide-area captured image are not only in the form of a specific image displayed on the display, but also in the same manner as the above-mentioned captured image. Of course, the data before it is generated as is also included.

1 Shape measuring device 3 Arithmetic processing device 6 Linear light source 11a First imaging unit 11b Second imaging unit 15 Imaging field control unit 18 Focus adjustment unit

Claims (8)

In a shape measuring device that measures the shape of the measurement surface of an object to be measured,
A linear light source that irradiates the measurement surface with linear light,
A first image pickup unit that captures a predetermined region including a light cut line on the measurement surface by the linear light and extracts a part of the acquired image as an optical cut line extraction image.
2.
An arithmetic processing unit that calculates the surface shape of the object to be measured based on the optical cut line extraction image, and
Have,
The arithmetic processing unit is
An optical cutting line position measuring unit that measures the optical cutting line position from the wide-area captured image, and a light cutting line position measuring unit.
When the optical cut line deviates from the light cut line extracted image in the first imaging unit, the extraction position for extracting the optical cut line extracted image from the captured image is set based on the light cut line position. An image pickup field control unit that changes the extraction position to include the optical cut line in the cut line extraction image, and
A shape measuring device. In a shape measuring device that measures the shape of the measurement surface of an object to be measured,
A linear light source that irradiates the measurement surface with linear light,
A first image pickup unit that captures a predetermined region including a light cut line on the measurement surface by the linear light and extracts a part of the acquired image as an optical cut line extraction image.
2.
An arithmetic processing unit that calculates the surface shape of the object to be measured based on the optical cut line extraction image, and
Have,
The arithmetic processing unit is
An optical cutting line position measuring unit that measures the optical cutting line position from the wide-area captured image, and a light cutting line position measuring unit.
Focus adjustment that changes the focus position of the first image pickup unit to a focus position that focuses on the light cut line based on the light cut line position when the first image pickup unit loses focus on the light cut line. Department and
A shape measuring device. In a shape measuring device that measures the shape of the measurement surface of an object to be measured,
A linear light source that irradiates the measurement surface with linear light,
A first image pickup unit that captures a predetermined region including a light cut line on the measurement surface by the linear light and extracts a part of the acquired image as an optical cut line extraction image.
2.
An arithmetic processing unit that calculates the surface shape of the object to be measured based on the optical cut line extraction image, and
Have,
The arithmetic processing unit is
An optical cutting line position measuring unit that measures the optical cutting line position from the wide-area captured image, and a light cutting line position measuring unit.
When the optical cut line deviates from the light cut line extracted image in the first imaging unit, the extraction position for extracting the optical cut line extracted image from the captured image is set based on the light cut line position. An image pickup field control unit that changes the extraction position to include the optical cut line in the cut line extraction image, and
Focus adjustment that changes the focus position of the first image pickup unit to a focus position that focuses on the light cut line based on the light cut line position when the first image pickup unit loses focus on the light cut line. Department and
A shape measuring device. The calculation processing apparatus according to any one of claims 1 to 3, wherein the arithmetic processing apparatus calculates the surface shape of the object to be measured based on the displacement amount of the optical cutting line included in the optical cutting line extracted image. Shape measuring device. In the shape measurement method for measuring the shape of the measurement surface of the object to be measured,
An irradiation step of irradiating the measurement surface with linear light,
A first imaging step in which a predetermined region including a light cut line on the measurement surface by the linear light is imaged by the first image pickup unit, and a part of the acquired image is extracted as an optical cut line extraction image.
A second image pickup unit acquires a wide area image captured by the second imaging unit, which includes at least an image pickup area of the optical cut line extracted image and an image of a region of the measurement surface which is wider than the image pickup area of the optical cut line extracted image. Imaging step and
An arithmetic processing step for calculating the surface shape of the measurement object based on the optical cut line extraction image, and
Have,
The arithmetic processing step is
The optical cut line position measurement step for measuring the optical cut line position from the wide area captured image, and
When the optical cut line deviates from the light cut line extracted image in the first imaging unit, the extraction position for extracting the optical cut line extracted image from the captured image is set based on the light cut line position. The imaging field control step for changing the extraction position in which the optical cut line is included in the cut line extraction image, and
A shape measuring method. In the shape measurement method for measuring the shape of the measurement surface of the object to be measured,
An irradiation step of irradiating the measurement surface with linear light,
A first imaging step in which a predetermined region including a light cut line on the measurement surface by the linear light is imaged by the first image pickup unit, and a part of the acquired image is extracted as an optical cut line extraction image.
A second image pickup unit acquires a wide area image captured by the second imaging unit, which includes at least an image pickup area of the optical cut line extracted image and an image of a region of the measurement surface which is wider than the image pickup area of the optical cut line extracted image. Imaging step and
An arithmetic processing step for calculating the surface shape of the measurement object based on the optical cut line extraction image, and
Have,
The arithmetic processing step is
The optical cut line position measurement step for measuring the optical cut line position from the wide area captured image, and
Focus adjustment that changes the focus position of the first image pickup unit to a focus position that focuses on the light cut line based on the light cut line position when the first image pickup unit loses focus on the light cut line. Steps and
A shape measuring method. In the shape measurement method for measuring the shape of the measurement surface of the object to be measured,
An irradiation step of irradiating the measurement surface with linear light,
A first imaging step in which a predetermined region including a light cut line on the measurement surface by the linear light is imaged by the first image pickup unit, and a part of the acquired image is extracted as an optical cut line extraction image.
A second image pickup unit acquires a wide area image captured by the second imaging unit, which includes at least an image pickup area of the optical cut line extracted image and an image of a region of the measurement surface which is wider than the image pickup area of the optical cut line extracted image. Imaging step and
An arithmetic processing step for calculating the surface shape of the measurement object based on the optical cut line extraction image, and
Have,
The arithmetic processing step is
The optical cut line position measurement step for measuring the optical cut line position from the wide area captured image, and
When the optical cut line deviates from the light cut line extracted image in the first imaging unit, the extraction position for extracting the optical cut line extracted image from the captured image is set based on the light cut line position. The imaging field control step for changing the extraction position in which the optical cut line is included in the cut line extraction image, and
Focus adjustment that changes the focus position of the first image pickup unit to a focus position that focuses on the light cut line based on the light cut line position when the first image pickup unit loses focus on the light cut line. Steps and
A shape measuring method. The calculation processing step is described in any one of claims 5 to 7, wherein the surface shape of the object to be measured is calculated based on the displacement amount of the optical cutting line included in the optical cutting line extracted image. Shape measurement method.

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