JP2008292434A - Optical cutting three-dimensional measurement instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To clarify the correspondence of a height found with respect to a marked position, irrespective of the resolution of an imaging device, and to find the height of an object with high accuracy. <P>SOLUTION: In this optical cutting three-dimensional measurement instrument 1, a projector 10 projects a slit light 100 onto the object 2, the imaging device 11 photographs a region which includes an optical cutting line 101 out of the object 2, from a direction different from a projection direction of the projector 10, and generates a picked-up image 110. An image processor 13 has a lightness-measuring function for tracking each of the plurality of marked positions existing in the object 2 moved by a conveying means 12 on the picked-up image 110, and for measuring at least three times imaged lightness and times during the period, when each marked position is included within a range where an illuminance varies by the slit light 100; a maximum value calculating function for finding the maximum value of the imaged lightness by using the three imaged lightness and times for every marked position; and a height calculation means function for finding a relative height between the marked positions by using the maximum value of the imaged lightness for each marked position. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical cutting three-dimensional measuring apparatus that measures the shape of an object.

  As a conventional three-dimensional measuring apparatus that measures the shape of an object, slit light is projected onto the object, and a captured image (two-dimensional image) of the object on which the slit light is projected is acquired. On the other hand, there is an apparatus (a three-dimensional measuring apparatus of the first conventional example) that obtains a pixel (maximum brightness) pixel (position of an object) by measuring the brightness of each pixel along the direction crossing the light cutting line. The three-dimensional measuring apparatus of the first conventional example recognizes the shape of the light section line from the set of positions of maximum brightness, and obtains the height of the object by using a triangulation method for the recognized shape of the light section line. be able to.

  However, in the three-dimensional measuring apparatus of the first conventional example, the slit light is projected toward the object from an oblique direction, so the position at which the slit light is projected differs depending on the height of the object. As a result, the three-dimensional measuring apparatus of the first conventional example accurately recognizes the position of the target object actually obtained from the shape of the light section line. There was a problem that could not. In other words, the measurement position differs depending on the height of the object.

In order to solve the above problem, Patent Document 1 discloses that a light pattern in which a bright region and a dark region are formed, not slit light, is projected onto an object, and a boundary line between the light region and the dark region of the light pattern is projected. By scanning the entire object within the exposure time of the image sensor (imaging device), the amount of received light at each measurement point of the object is measured, and the three-dimensional surface of the object is measured using the measured amount of received light. A three-dimensional measuring apparatus of a second conventional example for obtaining position information is disclosed. According to the three-dimensional measuring apparatus of the second conventional example, the three-dimensional shape of the object can be obtained in an extremely short time such as the exposure time of the image sensor.
Japanese Patent No. 2987000 (paragraphs 0020-0031 and FIGS. 1-7)

  However, in the second conventional example of the three-dimensional measuring apparatus, when the amount of light received at each measurement point is measured by the image sensor, the difference in the amount of received light is small between adjacent measurement points. There has been a problem in that it depends on the resolution of the light intensity of the light receiving element of the sensor (resolution of imaging brightness). Further, in the three-dimensional measuring apparatus of the second conventional example, as the length of the object in the scanning direction becomes longer, it is necessary to increase the speed of scanning the boundary line between the bright area and the dark area of the light pattern. The difference in the amount of received light at the adjacent measurement points is further reduced, resulting in a problem that the accuracy of the three-dimensional position information on the surface of the object is lowered. Further, in the three-dimensional measurement apparatus of the second conventional example, if the width of the boundary line increases, the difference in the amount of received light at adjacent measurement points cannot be clearly measured, and 3 on the surface of the object. There was a problem that the dimensional position information could not be obtained accurately.

  Also in the three-dimensional measuring apparatus of the first conventional example, the slit light projected onto the object has a width, so that a point shifted from the center in the width direction of the slit light is recognized as the center of the slit light. The shape of the optical cutting line could not be recognized with an accuracy narrower than the width of the slit light. For this reason, the three-dimensional measuring apparatus of the first conventional example has a problem that the height of the object cannot be obtained with high accuracy.

  The present invention has been made in view of the above points. The object of the present invention is to clarify the correspondence between the obtained height and the position of interest regardless of the resolution of the imaging apparatus, and to set the height of the object. An object of the present invention is to provide an optical cutting three-dimensional measuring apparatus that can be obtained with high accuracy.

  According to the first aspect of the present invention, there is provided projection means for projecting slit light onto an object to be measured, and the object provided integrally with the projection means and maintaining a predetermined interval in one direction with the projection means. Imaging means for photographing at least a region including the slit light projected onto the target object from a direction different from the projection direction of the projection means, and the relative position between the projection means and the imaging means and the target object. A plurality of relative position changing means for changing in one direction and a plurality of positions of interest on the object are tracked on a plurality of captured images taken by the imaging means when the relative positions are different; For each of the positions of interest, while the position of interest is within the range where the illuminance change due to the slit light occurs, the imaging brightness and relative position of the position of interest Brightness measurement means for measuring at least three times, and maximum value calculation means for obtaining the maximum value of the imaging brightness and the relative position that is the maximum value using the at least three imaging brightness and relative positions for each position of interest. And a height calculating means for obtaining a relative height between the positions of interest using a triangulation method with respect to a relative position where the imaging brightness of all the positions of interest is maximized.

  According to a second aspect of the present invention, in the first aspect of the invention, the imaging unit has at least three imaging elements arranged in the moving direction in which pixels are arranged in parallel with the slit light projected onto the object. It is characterized by that.

  According to a third aspect of the present invention, in the first aspect of the present invention, the imaging unit includes an imaging device in which pixels are arranged in a grid pattern, and the imaging is arranged in parallel with the slit light projected on the object. It is possible to read the imaging brightness of the element.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the maximum value calculating means monotonically increases like a projected intensity distribution of the slit light, and then monotonously decreases. A maximum value of the imaging brightness and the relative position at which the maximum value is obtained are obtained by applying and approximating at least three or more imaging brightness values.

  The invention of claim 5 is the invention of any one of claims 1 to 4, wherein when the relative position is changed in the one direction by the relative position changing means, the projection means and the imaging means are It is characterized by comprising a movement amount measuring means for actually measuring the relative movement amount of the object.

  The invention of claim 6 is an image according to any one of claims 1 to 5, wherein the maximum value of the imaging brightness for each of the positions of interest corresponds to the pixel value of the pixel assigned to each of the positions of interest. And a maximum value image generating means for generating.

  According to the first aspect of the present invention, the height of the object is determined with an accuracy narrower than the width of the slit light by determining the relative position at which the maximum value and the maximum value of the imaging brightness are obtained from the measured imaging brightness and the relative position. Can do. In addition, since the imaged lightness of the position of interest with the position fixed is measured, it is possible to recognize which position the height of the object is obtained.

  According to the second aspect of the invention, since at least three line sensors are arranged in parallel with the slit light pattern, high-speed and high-resolution imaging can be performed.

  According to the invention of claim 3, by using an area sensor capable of random access, it is possible to arbitrarily change the imaging region in accordance with the moving speed of the object and the configuration of the projection unit and the imaging unit. Therefore, high-speed and high-resolution imaging can be performed, and the device configuration can be easily changed.

  According to the fourth aspect of the present invention, the maximum value of the imaging brightness and the relative position that is the maximum value are obtained by applying the change of the imaging brightness acquired at the position of interest to the change function of the projection intensity in the direction crossing the light cutting line. The required accuracy can be improved.

  According to the invention of claim 5, even if the movement of the object is not a constant linear motion, by measuring the relative movement amount of the object with respect to the projection means and the imaging means, Can be accurately tracked on the captured image, so that highly accurate measurement can be performed.

  According to the sixth aspect of the present invention, since the maximum value of the imaging brightness is imaged for each position of interest, a gray image similar to that obtained when the object is irradiated with uniform light can be acquired. For example, it is possible to perform inspection using information on both the height and brightness of an object, or to use the measured three-dimensional shape data as a texture image necessary for CG display on a computer.

(Embodiment 1)
First, the structure of the light cutting three-dimensional measuring apparatus 1 of Embodiment 1 is demonstrated using FIGS. Fig.1 (a) is a block diagram of the optical cutting three-dimensional measuring apparatus 1 of this embodiment. The light cutting three-dimensional measuring apparatus 1 includes a projection device 10 that projects slit light 100 onto an object 2 to be measured, and at least a light cutting line (slit light projected onto the object 2) 101 of the object 2. An imaging device 11 that captures an area including the image from a direction different from the projection direction of the projection device 10, and a transport device (relative position variation means) that moves the object 2 in one direction (the direction of the arrow m1 in FIG. 1A). ) 12 and a plurality of target positions A to C (see FIG. 2) in the object 2 are tracked on the captured image 110, and the maximum value of the imaged lightness at each target position A to C is obtained. And an image processing device 13 for obtaining a relative height between the positions A to C.

  The projection device 10 is, for example, a slit laser light source or a projector, and projects the slit light 100 having an incident angle θ (see FIG. 1A) from the horizontal plane onto the object 2. The projected slit light 100 is reflected by the surface of the object 2 to form a light cutting line 101.

  The imaging device 11 is an area camera such as a television camera, for example, and includes a C-MOS imaging device capable of random access as an imaging device. This imaging device 11 arranges pixels in a square lattice pattern, and reads out pixel values of each pixel at random to form a captured image 110. The imaging device 11 is provided integrally with the projection device 10 and constitutes a projector / receiver 14. The imaging device 11 having such a configuration is arranged in parallel with the light cutting line 101 while maintaining a predetermined interval with the projection device 10 in one direction (the direction of the arrow m1 in FIG. 1A). It is possible to read the image brightness of the image sensor. The positional relationship during shooting of the projection device 10 and the imaging device 11 is fixed. The captured image 110 captured by the imaging device 11 is transferred to the image processing device 13.

  The conveying device 12 drives the object 2 so as to perform a linear motion at a constant speed in one direction orthogonal to the longitudinal direction of the slit light 100 (the direction of the arrow m1 in FIG. 1A). That is, the transport device 12 changes the relative position between the light projector / receiver 14 (projection device 10 and imaging device 11) and the object 2 in one direction.

  The image processing device 13 is, for example, a personal computer or a dedicated processing device or control device. When the captured image 110 is transferred from the imaging device 11, a plurality of images on the same line n (see FIG. 2) in the object 2. Each of the positions of interest A to C (see FIG. 2) is tracked on a plurality of captured images 110 photographed when the relative positions of the light projector / receiver 14 and the object 2 are different, and a plurality of positions of interest A to C are captured. Brightness measurement that measures the imaging brightness and time of the focus positions A to C three times while the focus positions A to C are included in the range in which the illuminance change due to the slit light 100 occurs. The relative value between the light emitting / receiving device 14 and the object 2 that is the maximum value and the maximum value of the imaging brightness using the function and the three imaging brightness values and times measured using the brightness measurement function for each of the positions of interest A to C. Maximum value detection function to obtain the position and Each imaged-lightness of interested position A~C has a height detection function of determining a relative height between the interested position A~C using triangulation to relative position becomes maximum. The image processing apparatus 13 includes a storage unit 130 and stores the captured image 110 transferred from the imaging apparatus 11. In addition, the imaging brightness of each focus position A-C and the frequency | count of measurement of time are not limited to 3 times, You may be 4 times or more.

  Next, the operation of the present embodiment will be described with reference to FIG. In FIG. 2, all the pixels of the image sensor are shown so that the entire light section line 101 can be seen eight times from imaging time t1 to t8 while moving the object 2 by the transport device 12 (see FIG. 1A). The read captured image 110 is shown. As the object 2 moves, the position of the object 2 on the captured image 110 appears to change. However, since the light emitter / receiver 14 (see FIG. 1A) is fixed, the light cutting line 101 on the captured image 110 looks almost the same position while being slightly deformed according to the shape of the object 2. .

  Here, attention is paid to three points A to C of the object 2. Since the object 2 is moving at a constant linear velocity, these positions of interest A to C are moved by a distance of d pixels each time on the two captured images 110 captured continuously, and the imaging time t1. The light cutting line 101 passes through between t8 and t8. The distance d is calculated as d = D / r from the actual movement amount D of the target object 2 between the imaging time intervals δ set in advance and the dimension r in the real space per pixel in the captured image 110. . Therefore, it is easy to track the target positions A to C of the moving object 2 on the captured image 110. The imaging brightness of each target position A to C when tracking each target position A to C is as shown in FIG.

  Since the positions of interest A to C are lower in the order of A, B, and C (see FIG. 1A), the light cutting line 101 is in the order of A, B, and C as shown in FIG. The image appears to be distorted downward in the imaging screen 110. For this reason, as shown in FIG. 3, the imaging time at which the imaging brightness is maximized differs for each of the positions of interest A to C. For example, when the target position B at which the imaging brightness is maximized at the imaging time t5 is the reference plane height, the optical cutting line 101 is at the imaging time interval δ × 2 times at the focused position A at which the imaging brightness is maximized at the imaging time t7. , That is, the amount moved by the imaging time interval δ × (−2) times, that is, −2D at the point C at which the imaging brightness is maximized at the imaging time t3. It can be estimated that it is only distorted. This amount of distortion is defined as a relative position between the light cutting line 101 (target object 2) and the light projector / receiver 14 when the imaging brightness is maximized at the positions of interest A and C. Since the slit light 100 is projected from the horizontal plane at an angle θ, as shown in FIG. 4, the target position A is higher than the target position B by 2Dtanθ, and the target position C is higher than the target position B. It can be determined that the position is lower by 2Dtanθ.

  In this way, imaging is performed at the imaging time interval δ while moving the object 2, the imaging brightness change at each of the target positions A to C is measured, and the imaging time and the reference at which the imaging brightness is maximized at the target positions A and C By calculating the difference from the imaging time at which the imaging brightness is maximized at the target position B, which is the surface height, the light emitter / receiver 14 and the light cutting line 101 (target) when the imaging brightness is maximized at the target positions A to C. By obtaining a relative position with respect to the object 2) and multiplying by the tangent of the incident angle θ of the slit light 100, the height information of the respective positions of interest A to C can be acquired.

  As described above, according to the present embodiment, the relative values of the light projector / receiver 14 and the object 2 that are the maximum value and the maximum value of the imaged lightness based on the imaged lightness and time measured at each target position A to C of each object 2. By obtaining the position, the height of the object 2 can be obtained with an accuracy narrower than the width of the slit light 100. In addition, since the imaging brightness of the positions of interest A to C where the positions are fixed is measured, it is possible to recognize which position of the target object 2 is being obtained.

  As a modification of the first embodiment, the transport device 12a only needs to relatively change the positional relationship between the object 2 and the light projector / receiver 14, so that the optical cutting three-dimensional measurement device 1b shown in FIG. Thus, the object 2 is fixed, and the light projector / receiver 14 is driven by the conveying device 12a so as to linearly move at a constant speed in the direction orthogonal to the direction of the slit light 100 (the direction of the arrow m2 in FIG. 1B). You may make it do.

(Embodiment 2)
When acquiring imaging brightness changes at each of the target positions A to C arranged in a line on the imaging screen 110, it is not necessary to read the entire captured image 110, and three target positions that move by a distance d pixels on the captured image 110. It is only necessary to track A to C and read only the imaging brightness of each of the positions of interest A to C.

  Therefore, the light-cutting three-dimensional measurement apparatus 1 according to the second embodiment captures only the pixel values of the horizontal scanning lines L1 to L8 that are separated by a distance d pixels in the vertical direction on each captured image 110 illustrated in FIG. It is assumed that data is read every δ. In addition, about the component similar to Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  In the second embodiment, the positions of interest A to C move from the scanning line L1 to the scanning line L8 at every imaging time interval δ on the captured image 110, so which of the scanning lines L1 to L8 is determined for each of the positions of interest A to C. It can be measured whether the imaging brightness is maximized at the position, and the imaging time at which the imaging brightness is maximized can be known. In addition, the imaging time at which the imaging brightness reaches the maximum at the reference plane height at the target positions A to C can be easily estimated because the imaging time interval δ is delayed with each imaging. Therefore, when the target object 2 moves and the target positions A to C pass through the slit light 100, the three-dimensional shape (height) is continuously provided for each pixel corresponding to the target positions A to C on the captured image 110. Information).

  Since there is a limit to the amount of data transferred per unit time in the digital transfer type imaging apparatus 11, the number of captured images 110 (frame rate) that can be captured within the unit time depends on the data amount of the image to be transferred. Therefore, according to the light-cutting three-dimensional measurement apparatus 1 of the present embodiment, only the pixel values of the eight scanning lines L1 to L8 that are separated by a distance d pixels in the vertical direction on the captured image 110 are read out continuously. Since the shape of the object 2 can be obtained, the frame rate can be increased by overwhelmingly reducing the amount of transfer data per one imaging compared to the conventional optical cutting three-dimensional measuring apparatus, and the unit time The number of measurement points for measuring the height information can be greatly increased.

  Further, the image processing apparatus 13 according to the second embodiment generates the image by associating the maximum value of the imaging brightness for each of the positions of interest A to C with the pixel value of the pixel assigned to each of the positions of interest A to C. It has an image generation function. In other words, in the light-cutting three-dimensional measuring apparatus 1 of the present embodiment, the maximum value of the imaging brightness can be obtained simultaneously with the imaging time at which the imaging brightness is maximized for each of the target positions A to C, so this value is recorded. If this is the case, a gray image similar to that obtained when the object 2 is irradiated with uniform light and photographed together with the height information can be acquired simultaneously.

  As described above, according to the second embodiment, by using an area sensor capable of random access, the imaging region is arbitrarily changed according to the moving speed of the target object 2 and the configurations of the projection device 10 and the imaging device 11. Therefore, high-speed and high-resolution imaging can be performed, and the device configuration can be easily changed.

  In addition, by imaging the maximum value of the imaging brightness for each of the positions of interest A to C, a grayscale image similar to the case where the object 2 is imaged by irradiating uniform light can be acquired. An inspection may be performed using both the height and brightness information of the object 2, or the measured three-dimensional shape data may be used as a texture image necessary for CG display (computer graphic display) on a computer. it can.

  As a modification of the second embodiment, the imaging device 11 is arranged in a direction orthogonal to the moving direction of the imaging region of the target object 2 in the captured image 110 when the relative position is changed in one direction by the transport device 12. It may have at least three line sensors (imaging devices) in which pixels are arranged in a line in the moving direction. That is, the imaging device 11 of the second embodiment has pixels arranged in a square lattice and can read out pixel values at arbitrary positions on the imaging device at random. Since the three-dimensional measuring apparatus 1 uses only pixel values on at least three scanning lines that are separated by a certain distance and parallel to the light cutting line 101, a plurality of line sensors are arranged in parallel with the light cutting line 101 imaged on the light receiving surface. The configuration is as follows. If conditions such as the moving speed of the object 2 and the positional relationship with the light projecting and receiving device 14 are defined in advance, the above configuration enables higher-speed measurement. Note that it is necessary to set the three line sensors in advance so that the light section line 101 is included in the imaging region of the at least three line sensors.

  According to the above modification, since at least three line sensors are arranged in parallel with the light cutting line 101, high-speed and high-resolution imaging can be performed.

  Note that the scanning lines need to have a number sufficient to capture the shape of the light cutting line 101. That is, it is necessary to set a larger number of scanning lines as the height range of the object 2 increases. For example, when measuring the object 2a having a triangular cross section as shown in FIG. 6A, the light cutting line 101 is greatly distorted in a letter C shape, so the number of scanning lines Li must be increased. However, if the cross-sectional shape of the target 2a is generally known, the scanning line Li can be measured with a small number of scanning lines Li by setting the scanning line Li substantially parallel to the light cutting line 101 as shown in FIG. It becomes possible. Even in the case of a configuration using a plurality of line sensors as described above, the irregular line sensor may be arranged so as to be substantially parallel to the light cutting line 101.

(Embodiment 3)
In the light-cutting three-dimensional measurement apparatus 1 according to the first embodiment, the image processing apparatus 13 obtains a relative position with respect to the light projector / receiver 14 based on the imaging time at which the imaging brightness is simply maximized for each of the positions A to C. However, in the light-cutting three-dimensional measurement apparatus 1 according to the present embodiment, the imaged lightness at a plurality of positions before and after crossing the light-cutting line 101 is obtained for each of the positions A to C, and the imaged lightness at the plurality of positions is obtained. Is used to obtain the relative position between the light emitter / receiver 14 and the object 2 when the imaging brightness is statistically maximized. That is, the image processing apparatus 13 uses the maximum value calculation function to approximate a function that monotonously increases like the projected intensity distribution of the light cutting line 101 and then monotonously decreases by applying at least three or more imaging brightness values. By doing so, the maximum value of the imaging brightness and the relative position that becomes the maximum value are obtained. Thereby, the resolution of height measurement can be improved. In addition, about the component similar to Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  For example, assuming that the imaging brightness when traversing the projected slit light 100 can be approximated to a quadratic function, the obtained imaging brightness I and time t are approximated to a quadratic function of Equation 1 by a least square approximation. The relative position p between the light projector / receiver 14 and the object 2 can be obtained by Equation 2.

  As described above, according to the third embodiment, by applying the change in the imaging brightness acquired at the target positions A to C to the change function of the projection intensity in the direction crossing the light cutting line 101, the maximum value and the maximum value of the imaging brightness are obtained. The accuracy for obtaining the relative position can be improved.

  In the third embodiment, the change in imaging brightness is approximated to a quadratic function. However, according to the actual change state of the projection intensity of the slit light 100, the brightness is not limited to a quadratic function, but may be a square wave or a Gaussian distribution. Any function that monotonously increases only once and monotonically decreases only once can be used.

  Further, the moving amount d of the object 2 on the captured image 110 during the imaging time interval δ is not necessarily an integer. In such a case, as shown in FIG. 7, the pixel values I (x, u) and I (x, u + 1) for two rows are read at the maximum integer d ′ interval not exceeding the movement amount d, and the coordinates (x , V) pixel values I ′ (x, v) can be interpolated from I (x, u) and I (x, u + 1) by Equation 3 to obtain imaging brightness closer to the true value. In particular, the accuracy can be improved when obtaining the time when the imaging brightness is maximized by function approximation as described above.

(Embodiment 4)
In the first embodiment, the target object 2 performs a linear motion at a constant speed. However, when the transport device 12 is a device whose feed rate is not constant, such as a belt conveyor, the target object 2 at the imaging time interval δ. Since an error occurs in the movement amount D, there is a problem that the measurement accuracy deteriorates. In addition, since the object 2 may meander on the belt conveyor, there is a problem in tracking the positions of interest A to C on the same line n on the captured image 110.

  Therefore, in the light cutting three-dimensional measuring apparatus 1 according to the fourth embodiment, the relative position between the light projector / receiver 14 and the target object 2 is indicated by the arrow in FIG. 1A by the transport device 12 illustrated in FIG. The imaging device 11 has a movement amount actual measurement function for actually measuring the relative movement amount of the object 2 with respect to the light projecting and receiving device 14 when the direction changes to the direction m1). In addition, about the component similar to Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As shown in FIG. 8A, the imaging device 11 of Embodiment 4 captures black and white stripe patterns printed at equal intervals on the conveying device 12 that is a belt conveyor at the position of the line camera visual field 15 at equal time intervals. Then, an image 111 as shown in FIG. By reading the stripe width w and the lateral position p in the image 111 of FIG. 8B, the moving speed and the lateral position when the object 2 crosses the light cutting line 101 can be measured. In this case, since the apparent movement amount d on the image 111 changes due to the variation c in the feed amount between the imaging time intervals δ, the scanning line has a width corresponding to the apparent variation amount γ = c / r of the feed amount. The pixel position for referring to the imaging brightness is adjusted based on the actually measured moving speed.

  As described above, according to the present embodiment, when the relative movement of the object 2 with respect to the light projector / receiver 14 (projection apparatus 10 and imaging apparatus 11) is actually measured, the movement of the object 2 is not a constant linear motion. Even so, the positions of interest A to C on the object 2 can be accurately tracked on the captured image 110, so that highly accurate measurement can be performed.

  As a modification of the fourth embodiment, position detection may be performed using an encoder.

(Embodiment 5)
In the first embodiment, the lens distortion of the imaging device 11 is negligible. However, when a camera having a wide-angle lens is used, the lens distortion cannot be ignored.

  Therefore, in the fifth embodiment, by using a test target as shown in FIG. 9A in advance, the reference point position is acquired over the entire captured image 110 as shown in FIG. The shape of the scanning line Li is deformed as shown in FIG. In addition, about the component similar to Embodiment 1, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  As described above, according to the present embodiment, it is possible to reduce the influence of lens distortion caused by the lens of the imaging device 11, so that highly accurate measurement can be performed.

(A) is a block diagram of the optical cutting three-dimensional measuring apparatus of Embodiments 1-5, (b) is a block diagram of the modification of Embodiment 1. FIG. It is a figure explaining how a light section line looks. It is a figure which shows the brightness change at the time of tracking the focus position on a target object. It is a figure explaining the principle which calculates | requires the height of a target object. FIG. 10 is a diagram for explaining a method for tracking a position of interest by setting a scanning line in the light-cutting three-dimensional measuring apparatus according to the second embodiment. In the above, in a modification of the scanning line setting method, (a) is a diagram showing the relationship between the projection device and the object, and (b) is a diagram showing the captured image. FIG. 10 is a diagram for explaining a method for interpolating imaging brightness in a modification of the third embodiment. In the optical cutting three-dimensional measuring apparatus of Embodiment 4, (a) is a top view of a conveyance apparatus, (b) is a figure which shows a captured image. In the optical cutting three-dimensional measuring apparatus of Embodiment 5, (a) is a figure which shows a test target, (b) is a figure which shows a captured image, (c) is a figure which shows a scanning line.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1a Optical cutting three-dimensional measuring apparatus 10 Projection apparatus 100 Slit light 101 Optical cutting line 11 Imaging apparatus 110 Captured image 12, 12a Conveyance apparatus 13 Image processing apparatus 2, 2a Object

Claims (6)

Projection means for projecting slit light onto the object to be measured;
A projection direction of the projection unit that is provided integrally with the projection unit and includes at least slit light projected on the target object while maintaining a predetermined interval in one direction with the projection unit. Imaging means for shooting from a different direction,
A relative position changing means for changing a relative position between the projection means and the imaging means and the object in the one direction;
Each of the plurality of positions of interest on the object is tracked on a plurality of captured images photographed by the imaging means when the relative positions are different, and the position of interest is relative to each of the plurality of positions of interest. Brightness measurement means for measuring the imaging brightness and the relative position of the position of interest at least three times while being included in the range in which the illuminance change due to the slit light occurs.
Maximum value calculation means for obtaining the maximum value of the imaging brightness and the relative position that is the maximum value using the at least three imaging brightness and relative positions for each of the positions of interest;
A light cutting unit comprising: height calculating means for obtaining a relative height between the positions of interest using a triangulation method with respect to a relative position where the imaging brightness of all the positions of interest is maximized. Dimensional measuring device.   2. The light-cutting three-dimensional image according to claim 1, wherein the imaging unit has at least three imaging elements in which pixels are arranged in parallel with the slit light projected on the object in the moving direction. Measuring device.   The image pickup unit includes an image pickup device in which pixels are arranged in a grid pattern, and can read out the image brightness of the image pickup device arranged in parallel with the slit light projected onto the object. The light cutting three-dimensional measuring apparatus as described.   The maximum value calculating means applies the at least three or more imaging brightnesses to a function that monotonously increases and then monotonously decreases like the projection intensity distribution of the slit light, thereby approximating the maximum imaging brightness. The optical cutting three-dimensional measurement apparatus according to claim 1, wherein the relative position that is a value and the maximum value is obtained.   And a moving amount measuring unit that measures a relative moving amount of the object relative to the projection unit and the imaging unit when the relative position is changed in the one direction by the relative position changing unit. The optical cutting three-dimensional measuring apparatus according to any one of claims 1 to 4.   6. The maximum value image generating means for generating an image by associating the maximum value of the imaging brightness for each target position with a pixel value of a pixel assigned for each target position. The light cutting three-dimensional measurement apparatus according to any one of the above.