JP5565222B2 - measuring device - Google Patents

Description

  The present invention relates to a measuring apparatus.

Conventionally, a method for measuring the position of an object to be measured based on an image captured using an area camera or a line sensor is known.
For example, Patent Document 1 below discloses a method of capturing a measurement object with two area cameras and obtaining a position from a stereo image.
Patent Documents 2 and 3 below disclose methods for obtaining only the height of a measurement object by attaching a special marker to the measurement object and imaging the marker with a line sensor.

  In the method disclosed in Patent Document 1, when an ordinary area camera is used, the resolution of the area camera is low and high-precision measurement cannot be performed. For this reason, when an area camera with high resolution is used in order to increase accuracy, there is a problem that the cost increases. In addition, when an area camera with a high resolution is used, there is a problem that the image size to be saved is enlarged.

  For this reason, when it is desired to obtain only the height of the measurement object, a line sensor is used as in the methods disclosed in Patent Documents 2 and 3 below. In the methods disclosed in the following Patent Documents 2 and 3, first, the focal length of the measurement object is obtained by the method disclosed in Non-Patent Document 1 below, and then the line is obtained by the method disclosed in Patent Document 2 below. The attitude of the sensor can be obtained.

Japanese Patent No. 3608305 JP 2009-300137 A JP 2009-300138 A

Japan Photogrammetry Society, Analytical Photogrammetry Committee, “Analytical Photogrammetry”, revised edition, Japan Photogrammetry Society, April 10, 1997, p. 149-152

  However, in Patent Documents 2 and 3, the distance from the imaging surface of the line sensor to the wall surface on which the measurement object is installed is known. Usually, since the imaging surface of the line sensor is hidden inside the outer box, it is difficult to install such a value as known.

  In addition, when it is desired to obtain not only the height of the measurement object but also the position, measurement is performed by combining an area camera and a line sensor in order to obtain the displacement. In this case, however, the measurement apparatus becomes large. There is a problem that the displacement using the area camera is less accurate than the height.

  In view of the above, an object of the present invention is to provide a measuring apparatus that can measure only height and both height and displacement with high accuracy by a line sensor and can be easily installed.

A measuring apparatus according to a first invention for solving the above-described problem is
A calibration target that knows absolute coordinates in five or more height directions,
A line sensor that captures an image of the calibration target and outputs an image signal of the captured image;
An input image creation unit for creating image information based on the image signal;
A target detection unit for detecting target coordinates based on the image information;
A coefficient calculation unit for calculating a coefficient of the DLT method based on the target coordinates and the absolute coordinates acquired in advance;
An attitude calculation unit that calculates the attitude of the line sensor based on the coefficient;
A focal length calculation unit for calculating a focal length of the line sensor based on the coefficient;
And a position calculator that calculates the position of the line sensor based on the coefficient.

A measuring apparatus according to a second invention for solving the above-described problem is
A calibration target with a cylindrical pole with five or more absolute coordinates,
A first line sensor that captures an image of a measurement object and outputs an image signal of the captured image;
A second line sensor that captures an image of the measurement object and outputs an image signal of the captured image;
An image creating unit that creates image information based on the image signal of the first line sensor and the image signal of the second line sensor;
A target detection unit that detects target coordinates of the first line sensor and target coordinates of the second line sensor based on image information of the first line sensor and image information of the second line sensor;
A coefficient calculation unit for calculating a coefficient of the DLT method based on the target coordinates and the absolute coordinates acquired in advance;
An attitude calculator that calculates attitudes of the first line sensor and the second line sensor based on the coefficient;
A focal length calculation unit that calculates focal lengths of the first line sensor and the second line sensor based on the coefficient;
And a position calculator that calculates positions of the first line sensor and the second line sensor based on the coefficient.
A measuring device according to a third invention for solving the above-described problem is the measuring device according to the second invention,
The target coordinates of the first line sensor and the target coordinates of the second line sensor, and the attitude and focus of the first line sensor acquired in advance by the attitude calculator, the focal distance calculator, and the position calculator. A stereo measurement unit that calculates target absolute coordinates based on the distance and position and the attitude, focal length, and position of the second line sensor is provided.
It is characterized by that.

  ADVANTAGE OF THE INVENTION According to this invention, only a height and both a height and a displacement can be measured with high precision with a line sensor, and the measuring apparatus with easy installation work can be provided.

1 is a schematic view of a measuring apparatus according to a first embodiment of the present invention. It is the schematic diagram which showed the structure of the measuring apparatus which concerns on the 1st Example of this invention. It is the flowchart which showed the procedure of the process in the measuring apparatus which concerns on 1st Example of this invention. It is the schematic diagram which showed the example of the calibration target in the measuring apparatus which concerns on 1st Example of this invention. It is explanatory drawing about DLT method. It is the schematic of the measuring apparatus which concerns on the 2nd Example of this invention. It is the schematic diagram which showed the coordinate system in the stereo measurement in the measuring apparatus which concerns on the 2nd Example of this invention. It is the schematic diagram which showed the structure of the measuring apparatus which concerns on the 2nd Example of this invention. It is the flowchart which showed the procedure of the process in the measuring apparatus which concerns on 2nd Example of this invention. It is the schematic of the measuring apparatus which concerns on the 3rd Example of this invention. It is the schematic diagram which showed the example of the calibration target in the measuring apparatus which concerns on the 3rd Example of this invention. It is the flowchart which showed the procedure of the process in the measuring apparatus which concerns on the 3rd Example of this invention. It is the schematic diagram which showed the example of the rhombus target in the measuring apparatus which concerns on the 3rd Example of this invention. It is the schematic diagram which showed the mode at the time of calibration target imaging in the measuring apparatus which concerns on 3rd Example of this invention. It is the schematic diagram which showed the example of the calibration target image in the measuring apparatus which concerns on 3rd Example of this invention.

  Hereinafter, embodiments for carrying out a measuring apparatus according to the present invention will be described with reference to the drawings.

Hereinafter, a first embodiment of the measuring apparatus according to the present invention will be described.
In the present embodiment, when the height of the measurement object is obtained by a line sensor with the configuration as described in Patent Documents 2 and 3, a necessary parameter is a DLT method (Direct Linear Transformation) described later (see Non-Patent Document 1 above). ) To obtain at once.

  However, in Patent Documents 2 and 3, the center of the line sensor is the imaging surface, but in this embodiment, the center of the line sensor is the lens center of the line sensor as in Non-Patent Document 1. Further, the method for obtaining the height from the captured image is also obtained by projection conversion as in Non-Patent Document 1.

  FIG. 1 is a schematic diagram of a measuring apparatus according to the present embodiment. FIG. 1A is a schematic view seen from the side of the measuring apparatus according to the present embodiment. Moreover, FIG.1 (b) is the schematic which looked at the target in the measuring apparatus which concerns on a present Example from the front.

  As shown in FIG. 1A, the measuring apparatus according to the present embodiment includes a line sensor 1, a calibration target 2 for obtaining parameters of the line sensor 1, and an illumination 3 that illuminates the calibration target 2. ing. The line sensor 1, the calibration target 2, and the illumination 3 are installed on an installation surface 4 serving as a reference such as the ground.

  As the calibration target 2, a calibration target 2 in which five or more absolute values are known within the movable range of the measurement object in the height direction (X-axis direction in FIG. 1) is used. For example, as shown in FIG. 1B, a stripe pattern of black 2a and white 2b whose stripe width is known is drawn within the movable range of the measurement object, and P0 to P4 are taken at the boundary. If the height from the installation surface 4 of the calibration target 2 to P0 is measured, the coordinates of P1 to P4 are relatively known. At this time, since the Z coordinates are all the same coordinates P0 to P4, for example, if it is set to 0, the distance from the calibration target 2 to the lens of the line sensor 1 can be known as a result of calibration.

FIG. 2 is a schematic diagram illustrating the configuration of the measurement apparatus according to the present embodiment.
As shown in FIG. 2, the measuring apparatus according to the present embodiment includes a line sensor 1, an input image creation unit 10, a storage unit 11 including a first memory 11a, a second memory 11b, and a third memory 11c. A target detection unit 12, a coefficient calculation unit 14, a focal length calculation unit 15, an attitude calculation unit 16, a position calculation unit 17, a memory 18, and a log output unit 19.

The line sensor 1 captures an image of the calibration target 2 and outputs an image signal of the captured image to the input image creation unit 10.
The input image creation unit 10 creates image information based on the input image signal and outputs the image information to the first memory 11 a of the storage unit 11.

The target detection unit 12 reads image information stored in the first memory 11 a of the storage unit 11, detects target coordinates x _{1 to} x _n based on the image information, and outputs the target coordinates x _{1 to} x _n to the second memory 11 b of the storage unit 11. To do.
The second memory 11b of the storage unit 11 stores absolute coordinates (X ₁ , Z ₁ ) to (X _n , Z _n ) in advance based on the target absolute coordinates 13 acquired in advance.

The coefficient calculation unit 14 reads the target coordinates x _{1 to} x _n and the absolute coordinates (X ₁ , Z ₁ ) to (X _n , Z _n ) stored in the second memory 11b of the storage unit 11 and reads the target coordinates x Coefficients b _{1 to} b ₅ are calculated based on _{1 to} x _n and absolute coordinates (X ₁ , Z ₁ ) to (X _n , Z _n ), and output to the third memory 11 c of the storage unit 11.

Focal length calculating unit 15 reads the third coefficient b ₁ stored in the memory 11c, b ₅ or coefficients b _2, b ₄ of the storage unit 11, the coefficient b _1, b ₅ or coefficients b _2, b ₄ Based on this, the focal length f is calculated and output to the memory 18.

Orientation calculation unit 16 reads the third coefficient stored in the memory 11c of b _1, b ₂ or coefficients b _4, b ₅ of the storage unit 11, based on the coefficients b _1, b ₂ or coefficients b _4, b ₅ The line sensor attitude φ is calculated and output to the memory 18.

Position calculating unit 17 reads the coefficient b ₁ ~b ₅ stored in the third memory 11c of the memory unit 11, calculates the line sensor position coordinates based on the coefficient _{b 1 ~b 5 (X 0,} Z 0) , Output to the memory 18.

Log output unit 19, the focal length f stored in the memory 18, reads the line sensor attitude φ and the line sensor coordinates (X _0, Z _0), the focal length f, the line sensor attitude φ and the line sensor coordinates (X _0, A log 20 of Z ₀ ) is recorded.

FIG. 3 is a flowchart illustrating a processing procedure in the measurement apparatus according to the present embodiment.
As shown in FIG. 3, first, in step P10, the calibration target 2 is imaged by the line sensor 1. It should be noted that all points corresponding to P _{0 to} P ₄ are entered during imaging. In FIG. 1B, the imaging line indicated by l in FIG. 1 passes through the center of the front of the calibration target 2 in the vertical direction, but may not be the center as long as all points are shown. Further, the imaging line does not have to be truly vertical.

ただし、Ｗは撮像の結果得られるラインセンサ画像の幅［ｐｉｘ］、Ｓはラインセンサ１上の素子の幅［ｍｍ］である。このとき、ラインセンサ１のセンサ中心が画像上の座標の原点となる。 Next, when the image captured by the input image creation unit 10 is binarized in step P11, a binarized image as shown in FIG. 4 is obtained.
Next, in step P12, the target detection unit 12 obtains coordinates on the image from the binarized image. Since the length [mm] on the sensor image of the line sensor 1 is used as the coordinates on the image, the number of pixels on the image x [pix] is used to obtain the following equation.

Here, W is the width [pix] of the line sensor image obtained as a result of imaging, and S is the width [mm] of the element on the line sensor 1. At this time, the sensor center of the line sensor 1 is the origin of coordinates on the image.

  Next, in step P13, calibration is performed by the coefficient calculation unit 14, the focal length calculation unit 15, the posture calculation unit 16, and the position calculation unit 17 using the DLT method (see Non-Patent Document 1 above). However, since it is redundant to use the three-dimensional DLT method as it is, it is assumed that it is reduced to two dimensions. By dropping the DLT method into two dimensions and rearranging it, the posture, focal length and position of the line sensor 1 can be obtained only by the DLT method. Further, all these parameters are obtained in a form including errors such as lens aberrations, so that high-precision measurement can be performed within the area where the calibration target 2 is imaged.

ここで、ａ₁〜ａ₄は、ラインセンサ１の姿勢行列Ｔの要素である。 Details of the calibration method in this embodiment will be described below.
As shown in FIG. 5, the measurement object M (X, Z) in the space when there is the lens center O _l of M and the line sensor 1 is collinear condition is satisfied. In FIG. 5, P indicates the imaging surface of the line sensor 1. That is, the following formula (2) is satisfied.

Here, a _{1 to} a ₄ are elements of the attitude matrix T of the line sensor 1.

となる。 That is,

It becomes.

The above equation (2) can be replaced with the following quadratic projective transformation equation using the coefficients b _{1 to} b ₅ .

上記式（５）は、ｂ₁〜ｂ₅について線形であるから、最低５点、すなわち５つの撮像対象物の座標（Ｘ₁，Ｚ₁）〜（Ｘ₅，Ｚ₅）と、それらを撮像したときのラインセンサ画像上の座標ｘ₁〜ｘ₅より回帰分析を行うことができる。このとき、ｘを被説明変数、Ｘ，Ｚ，ｘＸ，ｘＺを説明変数とする。 When the above equation (4) is modified, the following equation is obtained.

Since the above equation (5) is linear with respect to b _{1 to} b ₅ , at least five points, that is, the coordinates (X ₁ , Z ₁ ) to (X ₅ , Z ₅ ) of _five imaging objects and the images thereof are taken. The regression analysis can be performed from the coordinates x _{1 to} x ₅ on the line sensor image. At this time, x is an explanatory variable, and X, Z, xX, and xZ are explanatory variables.

From the above, the coefficients b _{1 to} b ₅ can be calculated. If absolute values of 5 points or more are not used, coefficients b _{1 to} b ₅ can also be obtained by expressing the matrix as follows and multiplying the inverse matrix obtained by the sweep-out method or the like from the left.

Incidentally, when comparing the above equation (2) the formula and (4), it can be seen that there is a following relationship for a ₁ ~a ₄ and b ₁ ~b _5. However, C = − (a ₃ X _l + a ₄ Z _l ).

By comparing the above equation (3) with the above equation (7), the posture φ of the line sensor 1 is as follows.

By comparing the above formula (3) with the above formula (7), the focal length f is as follows.

とすると、両辺の左からＢ^-1を掛けることで直ちに答えが得られる。 From the above equation (8),

Then, an answer can be obtained immediately by multiplying B ^-1 from the left of both sides.

としてもよい。 In addition, since the matrix T is an orthonormal matrix,

It is good.

Therefore, the coordinates x _{p0 to} x _p4 [pix] to x _{0 to} x ₄ [pix] on the image obtained in step P12 and the absolute coordinates P ₀ (X ₀ , Z ₀ ) to P ₄ (P X ₄ , Z ₄ ), it can be seen that the attitude, focal length, and lens center position (that is, the position of the line sensor 1) of the line sensor 1 can be obtained by the least square method.
Finally, in step P14, the obtained parameters are recorded as a log 20.

  As described above, according to the measuring apparatus according to the present embodiment, the posture, the focal length, and the position of the line sensor 1 can be obtained by calculation after the installation, so that the predetermined value is set when the line sensor 1 is installed. It is not necessary to fix to the angle of and can be installed easily.

  Further, according to the measuring apparatus according to the present embodiment, the posture, focal length, and position of the line sensor 1 can be obtained by calculation after the installation, so that it is not necessary to measure with another measuring device after the installation. For this reason, it does not receive the influence of the measurement error produced when measuring with another measuring device after installation.

  In addition, according to the measuring apparatus according to the present embodiment, the attitude, focus, and position of the line sensor 1 can be obtained by a unified method, so that sufficient accuracy can be obtained in the measurement region.

  Further, according to the measuring apparatus according to the present embodiment, the orientation, focal length, and position of the line sensor 1 can be changed as long as the calibration target 2 can be correctly installed without the line sensor 1 being directed vertically upward. Since the displacement of the imaging surface of the line sensor 1 can be absorbed on the parameter side, the line sensor 1 can be installed very easily.

The second embodiment of the measuring apparatus according to the present invention will be described below.
In the present embodiment, as described in Patent Document 1, stereo measurement that has been performed using an area camera is performed using two line sensors 1a and 1b. Thereby, it is not necessary to use a combination of an area camera and a line sensor in order to perform highly accurate measurement, so that the measuring apparatus can be configured compactly and at low cost.

  In addition, the position of the measurement object 5 can be calculated with high accuracy by a unified calculation method. Further, as can be seen from FIG. 7, the lens centers of the line sensors 1a and 1b may be located at any time when the measuring device is installed, so that the lens center is positioned at a predetermined position when the measuring device is installed. It is possible to eliminate troublesome work such as.

  However, in the stereo measurement using the two line sensors 1a and 1b, a very narrow area where the imaging surfaces of the two line sensors 1a and 1b indicated by P in FIG. From the calibration method, a rod-like object having a certain length and having a round cross section is suitable.

FIG. 6 is a schematic diagram of a measuring apparatus according to the present embodiment.
As shown in FIG. 6, the measuring apparatus according to the present embodiment includes a first line sensor 1a, a second line sensor 1b, and an illumination 3a on the first line sensor 1a side that illuminates the measurement object 5. An illumination 3b on the second line sensor 1b side that illuminates the measurement object 5 is provided. In the present embodiment, stereo measurement is performed using the first line sensor 1a and the second line sensor 1b.

  The first line sensor 1a and the second line sensor 1b have the same imaging plane by a calibration method described later, and in the coordinate system set as shown in FIG. 7, the first line sensor 1a and the second line sensor 1b. Assume that the posture, focal length, and lens center coordinates of the sensor 1b (that is, the positions of the first line sensor 1a and the second line sensor 1b) are obtained.

FIG. 8 is a schematic diagram illustrating the configuration of the measuring apparatus according to the present embodiment.
As shown in FIG. 8, the measuring apparatus according to this embodiment includes a first line sensor 1a, a second line sensor 1b, an input image creation unit 30, a first memory 31a, and a second memory 31b. And the memory | storage part 31 provided with the 3rd memory 31c, the target detection part 32, the stereo measurement part 34, and the log output part 35 are comprised.

  The first line sensor 1 a and the second line sensor 1 b capture an image of the measurement object 5 and output an image signal of the captured image to the input image creation unit 30. The input image creation unit 30 creates image information based on the input image signal and outputs the image information to the first memory 31 a of the storage unit 31.

The target detection unit 32 reads the image information stored in the first memory 31a of the storage unit 31, and based on the image information, the target coordinate x1 of the _first line sensor 1a and the target coordinate of the second line sensor 2a. x ₂ is detected and output to the second memory 31 b of the storage unit 31.

The second memory 31b of the storage unit 31 stores the posture φ _{1 of} the first line sensor 1a, the focal length f ₁ and the lens center O ₁ (that is, the _first center) from the line sensor posture log 33 acquired in advance. The position of the first line sensor 1a), the posture φ _{2 of} the second line sensor 1b, the focal length f ₂ and the lens center O ₂ (that is, the position of the second line sensor 1b) are stored in advance.

Stereo measurement unit 34 includes a target coordinate x ₂ of the second of the first line sensor 1a which is stored in the memory 31b the target coordinate x ₁ and the second line sensor 1b of the storage unit 31, the first line sensor 1a Posture φ ₁ , focal length f ₁ and lens center O _1, and posture φ ₂ , focal length f ₂ and lens center O _{2 of} the second line sensor 1 b are read, and target coordinates x of the first line sensor 1 a are read. The target coordinates x _{2 of the first} and second line sensors 1b, the posture φ _{1 of} the first line sensor 1a, the focal length f ₁ and the lens center O ₁ , the posture φ _{2 of} the second line sensor 1b, and the focal length The target absolute coordinates are calculated based on f ₂ and the lens center O _2, and are output to the third memory 31 c of the storage unit 31.

  The log output unit 35 reads the target absolute coordinates stored in the third memory 31 c of the storage unit 31 and records a target absolute coordinate log 36.

FIG. 9 is a flowchart illustrating a processing procedure in the measurement apparatus according to the present embodiment.
As shown in FIG. 9, first, in step P20, an image of the measurement object is captured by the first line sensor and the second line sensor.
Next, in step P21, the coordinates of the measurement location 5a are converted from [pix] to [mm] by the same method as in step P12 according to the first embodiment. And the coordinate of the measurement location 5a (refer FIG. 6) is calculated | required.
Next, in step P22, stereo measurement is performed. In addition, stereo measurement can be performed as follows using a coordinate system as shown in FIG.

In FIG. 7, the lens center of the first line sensor corresponds to O ₁ (X ₀₁ , Z ₀₁ ), and the lens center of the second line sensor corresponds to O ₂ (X ₀₂ , Z ₀₂ ). target coordinates on the imaging plane when the imaging in the line sensor is x _1, the target coordinates on the imaging plane when the image pickup in the second line sensor is assumed to be x _2. In the coordinate system shown in FIG. 7, target coordinates x ₁ and x ₂ are expressed as follows.

Therefore, the coordinates (X, Z) of the measurement location 5a (see FIG. 6) of the measurement object can be expressed as follows.

最後に、ステップＰ２３において、測定結果をログに記録する。 Here, f ₁ is the focal length of the first line sensor, f ₂ is the focal length of the second line sensor, and t1 and t2 are as follows.

Finally, in step P23, the measurement result is recorded in a log.

  As described above, according to the measuring apparatus according to the present embodiment, the position of the measurement object can be measured easily and with high accuracy using only the first line sensor and the second line sensor.

  In addition, since only the first line sensor and the second line sensor are used, the measuring apparatus can be configured compactly and at low cost.

  Further, according to the measuring apparatus according to the present embodiment, when the measurement target is a rod-shaped object, unlike the above-described Patent Documents 2 and 3, the rod-shaped object itself can be measured.

The third embodiment of the measuring apparatus according to the present invention will be described below.
In the present embodiment, the first line sensor 1a and the second line sensor 1a and the second line sensor 1b, which are used for calculation, are combined with the imaging surfaces of the first line sensor 1a and the second line sensor 1b in the measurement apparatus according to the second embodiment. The parameter of the line sensor 1b is obtained. Thereby, since the imaging surfaces of the first line sensor 1a and the second line sensor 1b can be matched by a predetermined procedure, the measuring apparatus according to the second embodiment can be realized more realistically.

  FIG. 10 is a schematic diagram of a measuring apparatus according to the present embodiment. In addition, Fig.10 (a) is the schematic seen from the front of the measuring apparatus which concerns on a present Example. Moreover, FIG.1 (b) is the schematic which looked at the rhombus target in the measuring apparatus based on a present Example from the front.

  As shown in FIG. 10, the measuring apparatus according to the present embodiment includes a first line sensor 1a, a second line sensor 1b, and a first line sensor 1a and a second line sensor as shown in FIG. A rhombus in which a plurality of rhombuses for matching the calibration target 6 for obtaining the parameter 1b and the imaging lines of the first line sensor 1a and the second line sensor 1b as shown in FIG. 10B are drawn. A target 7, an illumination 3 a on the first line sensor 1 a side that illuminates the calibration target 6 and the rhombus target 7, and an illumination 3 b on the second line sensor 1 b side that illuminates the calibration target 6 and the rhombus target 7 are provided. Yes. In the present embodiment, the calibration target 6 is installed on a pan head (not shown) whose rotation angle can be adjusted so that the direction in which the front side faces can be easily adjusted. To do.

In the present embodiment, as shown in FIG. 11, the calibration target 6 can fix five or more cylindrical poles 6a having a circular cross section and can know the absolute coordinates of each pole 6a. Keep it. For example, in the case of placing five poles 6a, as shown in FIG. 10, leave as seen only the absolute coordinates of P _0, when placing a P ₁ to P ₄ as seen relative coordinates from P ₀ Good.

  In this embodiment, the calibration method in the measuring apparatus according to the first embodiment can be applied as it is by combining the imaging surfaces of the first line sensor 1a and the second line sensor 1b. is there. Therefore, the configuration of the measuring apparatus according to the present embodiment is the same as the configuration of the measuring apparatus according to the first embodiment.

  That is, in this embodiment, the image creation unit that creates image information based on the image signal of the first line sensor 1a and the image signal of the second line sensor 1b, the image information of the first line sensor 1a, and the first A target detection unit for detecting the target coordinates of the first line sensor 1a and the target coordinates of the second line sensor 1b based on the image information of the second line sensor 1b, and the DLT based on the target coordinates and the previously acquired absolute coordinates. A coefficient calculation unit for calculating the modulus of the modulus, an attitude calculation unit for calculating the attitudes of the first line sensor 1a and the second line sensor 1b based on the coefficients, and the first line sensor 1a and the second line sensor based on the coefficients The focal length calculation unit for calculating the focal length of the line sensor 1b, and the positions of the first line sensor 1a and the second line sensor 1b based on the coefficients. And a position calculator for calculation.

FIG. 12 is a flowchart illustrating a processing procedure in the measurement apparatus according to the present embodiment.
As shown in FIG. 12, first, in step P30, the rhombus target 7 is placed on the pole 6a of the calibration target 6 as shown in FIG. Then, the first line sensor 1 a and the second line sensor 1 b are captured while capturing the rhombus target 7 so that the imaging surfaces of the first line sensor 1 a and the second line sensor 1 b coincide on the calibration target 6. Adjust the rotation angle of the installed pan head.

  Here, in FIG. 13B, when the rhombus target 7 is imaged, the imaging surfaces of the first line sensor 1a and the second line sensor 1b are indicated by A and A ′ in FIG. It is an example of the image in the imaging line which crosses the rhombus target.

  FIG. 13C shows a rhombus as shown by B and B ′ in FIG. 13A when the imaging surfaces of the first line sensor 1a and the second line sensor 1b when the rhombus target 7 is imaged. It is an example of the image in the imaging line which crosses the target.

  FIG. 13D shows an imaging line in which the imaging surfaces of the first line sensor 1a and the second line sensor 1b cross the rhombus target 7 as indicated by C in FIG. 13A when the rhombus target is imaged. It is an example of an image.

  And as shown in FIG.13 (d), when the imaging surface of the 1st line sensor 1a and the 2nd line sensor 1b crosses the center of the rhombus target 7, the 1st line sensor 1a and the 2nd line sensor The imaging surfaces of 1b coincide.

Next, in step P31, as shown in FIG. 14, the rhombus target 7 is removed from the pole 6a of the calibration target 6, and then imaged by the first line sensor 1a and the second line sensor 1b. At this time, as shown in FIGS. 15A and 15B, P _{0 to} P of each pole 6 a is obtained between the image captured by the first line sensor 1 a and the image captured by the second line sensor 1 b. Note that the location of ₄ changes. In this embodiment, the number of poles 6a is five, but care must be taken when the number of poles 6a is further increased.

Next, in Step P32, since illumination is applied from below the poles 6a arranged on the calibration target 6, P _{0 to} P ₄ of the poles 6a arranged on the calibration target 6 are captured images. By binarizing the signal, the image becomes white and an image of the first line sensor 1a as shown in FIG. 15A and an image of the first line sensor 1b as shown in FIG. 15B are obtained. Can do.

  Next, in step P33, coordinates [mm] on the image are obtained from the binarized image. First, as shown in FIG. 15C, the center of the width of the white portion of each pole 6a is obtained, and the number of pixels x [pix] from the left end of the image is obtained. Next, the coordinate x [mm] on the image is obtained by the same method as in Step P12 according to the first embodiment.

Next, in step P34, calibration is performed. In this embodiment, since it is the same as the calibration method in the measuring apparatus according to the first embodiment, detailed description thereof is omitted here.
Next, in step P35, the obtained parameters are recorded as a log.
Finally, in step P36, it is determined whether the parameters of the first line sensor 1a and the second line sensor 1b have been obtained. If the parameters of the first line sensor 1a and the second line sensor 1b have been obtained, When the above process is finished and the parameters of the first line sensor 1a and the second line sensor 1b have not been obtained, Steps P31 to P36 are executed again.

  As described above, according to the measuring apparatus according to the present embodiment, the imaging surfaces of the first line sensor 1a and the second line sensor 1b can be matched by a certain procedure, and thus the second embodiment is used. Such a measuring apparatus can be realized more realistically.

  The present invention can be used, for example, in a measuring apparatus using a line sensor.

DESCRIPTION OF SYMBOLS 1 Line sensor 1a 1st line sensor 1b 2nd line sensor 2 Calibration target 3,3a, 3b Illumination 4 Installation surface 5 Measurement object 6 Calibration target 7 Diamond target

Claims (3)

A calibration target that knows absolute coordinates in five or more height directions,
A line sensor that captures an image of the calibration target and outputs an image signal of the captured image;
An input image creation unit for creating image information based on the image signal;
A target detection unit for detecting target coordinates based on the image information;
A coefficient calculation unit for calculating a coefficient of the DLT method based on the target coordinates and the absolute coordinates acquired in advance;
An attitude calculation unit that calculates the attitude of the line sensor based on the coefficient;
A focal length calculation unit for calculating a focal length of the line sensor based on the coefficient;
And a position calculation unit that calculates a position of the line sensor based on the coefficient. A calibration target with a cylindrical pole with five or more absolute coordinates,
A first line sensor that captures an image of a measurement object and outputs an image signal of the captured image;
A second line sensor that captures an image of the measurement object and outputs an image signal of the captured image;
An image creating unit that creates image information based on the image signal of the first line sensor and the image signal of the second line sensor;
A target detection unit that detects target coordinates of the first line sensor and target coordinates of the second line sensor based on image information of the first line sensor and image information of the second line sensor;
A coefficient calculation unit for calculating a coefficient of the DLT method based on the target coordinates and the absolute coordinates acquired in advance;
An attitude calculator that calculates attitudes of the first line sensor and the second line sensor based on the coefficient;
A focal length calculation unit that calculates focal lengths of the first line sensor and the second line sensor based on the coefficient;
A measurement apparatus comprising: a position calculation unit that calculates positions of the first line sensor and the second line sensor based on the coefficient. Before SL and the target coordinates and target coordinates of the second line sensor of the first line sensor, the posture computing unit, the posture of the first line sensor obtained in advance by the focal length calculating unit and the position calculating unit, The measurement apparatus according to claim 2, further comprising a stereo measurement unit that calculates a target absolute coordinate based on a focal length and a position, and an attitude, a focal length, and a position of the second line sensor.

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