JP5494267B2 - Three-dimensional shape measuring apparatus, calibration method for three-dimensional shape measuring apparatus, and robot apparatus - Google Patents

Description

  The present invention relates to a three-dimensional shape measurement apparatus, a calibration method for a three-dimensional shape measurement apparatus, and a robot apparatus.

The slit light source emits slit light, and the camera captures the bright line (light cutting line) of the slit light reflected on the surface of the object to be measured, and the arithmetic processing unit performs triangulation based on the image of the optical cutting line captured. A three-dimensional shape measurement technique for measuring a three-dimensional shape of a measurement target object based on the principle of is known. This three-dimensional shape measurement technique is also called an optical cutting method.
When measuring an object to be measured, such as a precision part, with a complicated outer shape by the light cutting method, there is a portion that cannot be measured because the optical cutting line is hidden only by imaging from one specific direction. May occur or a portion with poor measurement accuracy may occur. In addition, when measuring a measurement target object with a large shape, shape measurement can only be performed with a measurement accuracy lower than the desired measurement accuracy due to the limit of the resolution of the camera only by imaging from one specific direction. There is.
Conventionally, in order to solve such a problem, a three-dimensional shape measuring apparatus that measures a three-dimensional shape by providing a plurality of cameras that capture images from different directions is known (see, for example, Patent Document 1).

JP 2007-93412 A

In the three-dimensional shape measurement apparatus using the light section method, calibration (calibration) is required to match the position of the light section line in the image of the measurement target object captured by the camera with the position in the real space corresponding to the position. is necessary. Conventionally, in a light cutting method three-dimensional shape measuring apparatus using a plurality of cameras, calibration is performed for each camera, and a great amount of time and troublesome work have occurred in the calibration work. This problem also occurs in a three-dimensional shape measuring apparatus that changes the position of the camera with respect to a fixed slit light source and performs imaging from a plurality of directions.
Therefore, the present invention has been made to solve the above-described problem. Calibration of a three-dimensional shape measuring apparatus that measures a three-dimensional shape by imaging a measurement target object from a plurality of directions is performed with a simple operation. An object of the present invention is to provide a three-dimensional shape measuring apparatus, a three-dimensional shape measuring apparatus calibration method, and a robot apparatus that can be performed in a short time.

[1] In order to solve the above-described problem, in the three-dimensional shape measuring apparatus according to one aspect of the present invention, a plurality of imaging units captures a light cutting line reflected in a portion irradiated with slit light emitted from a light source unit. In a three-dimensional shape measurement apparatus that performs three-dimensional shape measurement, an optical cutting line by the slit light irradiated to the calibration block from a plurality of captured images captured by the calibration block and each of the plurality of imaging units An optical cutting line detection unit for detecting the respective feature points, a feature point detection unit for detecting coordinate values of feature points from the plurality of optical cutting lines respectively detected by the optical cutting line detection unit, and a feature in each of the plurality of captured images A coordinate conversion parameter calculation unit for calculating a coordinate conversion parameter for converting the coordinate value of the point into a coordinate value of a single coordinate system.
According to this configuration, the coordinate conversion parameter calculation unit converts the feature point coordinate value of the light cutting line of the calibration block in each captured image captured by the plurality of imaging units into a coordinate value of a single coordinate system. Calculate coordinate transformation parameters. By obtaining the coordinate conversion parameters, the three-dimensional shape measuring apparatus can easily connect the captured images obtained from the plurality of imaging units having different imaging directions to construct a single image plane. The calibration block only needs to be placed so that a plurality of imaging units can capture images. Further, since detailed scanning of the light section line is not required for calibration, according to the three-dimensional shape measuring apparatus which is one embodiment of the present invention, calibration can be performed in a short time with a simple operation.

[2] The three-dimensional shape measuring apparatus according to [1], wherein the calibration block has a plane to be irradiated with the slit light, and the plane is a reference for calibration of the three-dimensional shape measuring apparatus. It is provided to be parallel to the surface.
According to this configuration, it is possible to easily perform calibration at a constant height in a short time using a simple-shaped calibration block.
[3] In the three-dimensional shape measuring apparatus according to [1] or [2], the coordinate conversion parameter calculation unit includes an equation representing a surface of the slit light, camera parameters of each of the plurality of imaging units, and the calibration. The coordinate transformation parameter is calculated based on the height dimension value of the block for use.
According to this configuration, calibration at a desired height can be performed easily and in a short time.
[4] In the three-dimensional shape measuring apparatus according to [3], the coordinate conversion parameter calculation unit calculates a plurality of coordinate conversion parameters according to each of a plurality of height dimension values of the calibration block, It is characterized by linearly interpolating a plurality of coordinate transformation parameters.
According to this configuration, it is possible to easily obtain a correspondence relationship having an arbitrary height in a short time.

[5] In order to solve the above-described problem, a calibration method for a three-dimensional shape measuring apparatus according to an aspect of the present invention includes a plurality of imaging units that display a light cutting line reflected in a portion irradiated with slit light emitted from a light source unit. In a calibration method for a three-dimensional shape measuring apparatus that takes an image and measures a three-dimensional shape, light cutting by the slit light emitted to the calibration block from a plurality of picked-up images picked up by each of the plurality of image pickup units A light cutting line detection step for detecting each line, a feature point detection step for detecting coordinate values of feature points from the plurality of light cutting lines detected in the light cutting line detection step, and a feature in each of the plurality of captured images A coordinate transformation parameter calculation step that calculates coordinate transformation parameters for transforming point coordinate values to coordinate values in a single coordinate system. And having a flop, a.
According to this procedure, the coordinate conversion parameter calculation step converts the feature point coordinate value of the light cutting line of the calibration block in each captured image captured by the plurality of imaging units into a coordinate value of a single coordinate system. Calculate coordinate transformation parameters. By obtaining the coordinate conversion parameters, the three-dimensional shape measuring apparatus can easily connect the captured images obtained from the plurality of imaging units having different imaging directions to construct a single image plane. The calibration block only needs to be placed so that a plurality of imaging units can capture images. Further, since the calibration does not require detailed scanning of the light section line, according to the calibration method of the three-dimensional shape measuring apparatus which is one aspect of the present invention, calibration is performed in a short time with a simple operation. be able to.

[6] In order to solve the above-described problem, in the robot apparatus according to one aspect of the present invention, the imaging unit captures a three-dimensional shape measurement by imaging the light cutting line reflected in the slit light irradiated portion emitted by the light source unit. In a robot apparatus to perform, a calibration block, a hand unit to which the imaging unit is attached, an arm unit to which the hand unit is movably attached, and the hand unit and the arm unit are operated in combination. The position of the imaging unit is changed, and the calibration block is irradiated from a measurement control unit that causes the imaging unit to capture an image at the changed position and a plurality of captured images captured by each of the plurality of imaging units. A light cutting line detection unit that detects a light cutting line by the slit light, and a plurality of light cutting lines detected by the light cutting line detection unit, respectively. And a coordinate conversion parameter calculation unit for calculating a coordinate conversion parameter for converting the coordinate value of the feature point in each of the plurality of captured images into a coordinate value of a single coordinate system. And.
According to this configuration, the coordinate conversion parameter calculation unit converts the feature point coordinate value of the light section line of the calibration block in each captured image captured by the imaging unit at a plurality of positions into a coordinate value of a single coordinate system. Calculate the coordinate transformation parameters for By obtaining the coordinate conversion parameters, the robot apparatus can easily connect the captured images sequentially obtained from the imaging units having different imaging positions to construct a single image plane. The calibration block only needs to be placed so that the imaging unit can capture images at all of a plurality of positions. Further, since the calibration does not require detailed scanning of the light section line, the robot apparatus according to one embodiment of the present invention can perform calibration in a short time with a simple operation.

1 is a schematic diagram of a three-dimensional shape measuring apparatus and a calibration block, schematically showing how the three-dimensional shape measuring apparatus according to the first embodiment of the present invention performs calibration. It is a block diagram which shows the main function structures of the three-dimensional shape measuring apparatus in the embodiment. In the same embodiment, it is the figure which showed typically a mode that the light cutting line detection part zigzag scans a window within the captured image area | region. In the same embodiment, it is a figure which shows the two-dimensional coordinate of the feature point which the feature point detection part detected from two captured image areas. In the same embodiment, it is a flowchart which shows the procedure of the camera parameter calculation process about one imaging part which a three-dimensional shape measuring apparatus performs. In the same embodiment, it is a flowchart which shows the procedure of the coordinate transformation parameter calculation process which a three-dimensional shape measuring device performs. It is the schematic of the robot apparatus and the block for a calibration which showed a mode that the robot apparatus which is 2nd Embodiment of this invention performed calibration. FIG. 2 is a block diagram showing a main functional configuration of the robot apparatus in the same embodiment. 4 is a flowchart illustrating a procedure of coordinate transformation parameter calculation processing executed by the robot apparatus in the embodiment. It is a perspective view of the appearance of a calibration block provided with a plurality of planes having different height dimensions.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.
[First Embodiment]
FIG. 1 is a schematic diagram of a three-dimensional shape measuring apparatus and a calibration block schematically showing how the three-dimensional shape measuring apparatus according to the first embodiment of the present invention performs calibration. In the figure, a three-dimensional shape measurement apparatus 1 is an apparatus that measures the external shape of a measurement target object (including a calibration block) by a light cutting method, and operates by switching to a calibration mode or a normal measurement mode. To do. The light cutting method refers to, for example, a bright line (light cutting) in which the slit light source irradiates the measurement target object with slit light while the slit light source and the measurement target object are moved relative to each other, and the imaging device reflects on the surface of the measurement target object. Line) to obtain a two-dimensional bright line image, and the image processing apparatus calculates the three-dimensional shape of the measurement object based on the principle of triangulation based on the bright line image.

  As shown in FIG. 1, the three-dimensional shape measuring apparatus 1 includes a light source unit 11, two imaging units 12 (imaging units 12-1 and 12-2), and a mounting table 40. In the figure, the mounting table 40 has a two-dimensional position of the optical cutting line in the captured images captured by the imaging units 12-1 and 12-2 and a tertiary in real space corresponding to the two-dimensional position. A calibration block 100 used for matching with the original position is placed. That is, the calibration block 100 is a measurement target object used when the three-dimensional shape measurement apparatus 1 operates in the calibration mode.

  First, the calibration block 100 will be described. The calibration block 100 is a measurement target object used for performing calibration in the height direction (Z-axis upward direction). The calibration block 100 is a solid block having an upper surface 101 that is parallel to the placement surface (calibration reference surface) when placed on the placement table 40. For example, the calibration block 100 is a cuboid solid. It is a block. The calibration block 100 may be hollow or concave. The placement side of the calibration block 100 has a surface or at least four support portions in order to ensure the stability of the installation.

  Since the upper surface 101 of the calibration block 100 is irradiated with, for example, laser light, the temperature of the irradiated portion tends to increase. Therefore, the calibration block 100 is preferably formed of a material having a small coefficient of thermal expansion. For example, the calibration block 100 can be made of carbon black, glass, or stainless steel. Among these, carbon black is excellent in that the mass can be reduced as compared with glass and stainless steel, and is preferable as a material. In order to easily reflect the irradiated laser light, at least the upper surface 101 of the calibration block 100 is blasted.

  The calibration block 100 is one of a plurality of solid blocks having different distances (height dimensions) between the mounting surface of the mounting table 40 and the upper surface 101 of the calibration block 100. The height dimension of each individual block is measured by a shape measuring device other than the three-dimensional shape measuring device 1 according to this embodiment and is known. For each solid block, reference data in which the identifier of the solid block is associated with the height dimension value is created. This reference data is stored in advance in a storage unit described later.

  Next, the functional configuration of the three-dimensional shape measuring apparatus 1 will be described. FIG. 2 is a block diagram showing the main functional configuration of the three-dimensional shape measuring apparatus 1. In the figure, the same components as those shown in FIG. As shown in FIG. 2, the three-dimensional shape measurement apparatus 1 includes an optical measurement unit 10, a control unit 20, a mounting table driving unit 30, and a mounting table 40. Hereinafter, the functional configuration of the three-dimensional shape measuring apparatus 1 will be described with reference to FIGS. 1 and 2 together.

The optical measurement unit 10 is a measurement unit that performs three-dimensional shape measurement by a light cutting method, and includes a light source unit 11 and two imaging units 12 (imaging units 12-1 and 12-2). .
The light source unit 11 is a slit light source that emits slit light SL into space. The slit light SL is, for example, laser light or tungsten light. The light source unit 11 is fixedly installed with a predetermined angle at which the central optical axis of the slit light SL is not parallel to the vertical axis.

  The imaging unit 12 is an imaging device that captures a test chart of a checker pattern used to cause the control unit 20 to calculate camera parameters, or captures reflected light of the slit light SL from the measurement target object. The imaging unit 12 is, for example, a digital camera or a digital video camera. Since the irradiated portion of the slit light SL irradiated to the measurement target object is visualized as a bright line LL, the imaging unit 12 captures and captures the reflected light from the measurement target object by the bright line LL. The imaging unit 12 images the bright line LL reflected on the measurement target object, and supplies the captured image data to the control unit 20.

  The imaging unit 12 is installed at a position where the optical axis of the imaging lens is inclined at a predetermined angle that is not parallel to the central optical axis of the slit light SL. That is, the imaging units 12-1 and 12-2 are installed in directions in which the respective captured image areas IA-1 and IA-2 (also collectively referred to as captured image areas IA) partially overlap. More preferably, the imaging units 12-1 and 12-2 are oriented so that the captured image areas IA-1 and IA-2 partially overlap according to the shape of the measurement target object, and the bright lines LL mutually. The installation direction is appropriately changed to compensate for the hiding.

  The control unit 20 controls the entire three-dimensional shape measurement apparatus 1, and performs control for switching between a calibration mode and a normal measurement mode by a selection signal supplied from the outside, for example. The control unit 20 is configured to include a CPU (Central Processing Unit) and a storage unit (both not shown), and in terms of its functions, the measurement control unit 21, the camera parameter calculation unit 22, and the light section line detection unit 23 are included. And a feature point detection unit 24 and a coordinate conversion parameter calculation unit 25.

  The measurement control unit 21 controls the optical measurement unit 10 and the mounting table driving unit 30. Specifically, the measurement control unit 21 controls the light source unit 11 to start and stop the emission of the slit light SL. The measurement control unit 21 controls the imaging unit 12 to image a checker pattern test chart and supply the captured image data to the camera parameter calculation unit 22. In addition, the measurement control unit 21 controls the imaging unit 12 to capture the bright line LL reflected in the measurement target object and supply the captured image data to the light section line detection unit 23. In addition, the measurement control unit 21 moves the mounting table 40 in at least one of the X direction and the Y direction on the mounting surface with respect to the mounting table driving unit 30, or uses the approximate center position of the mounting surface as a central point. Control which rotates the mounting base 40 is performed.

  In the calibration mode, the camera parameter calculation unit 22 takes in the captured image data supplied from the imaging units 12-1 and 12-2, and for each imaging unit 12, the two-dimensional coordinate values of the checker pattern included in the captured image. Based on the camera calibration. The camera calibration is a process of calculating camera parameters including internal parameters that are unique information of the imaging unit 12 and external parameters that indicate positions and orientations in the world coordinate system.

In the calibration mode and the normal measurement mode, the light section line detection unit 23 captures captured image data supplied from the imaging units 12-1 and 12-2, and captures image areas IA-1 and IA of each captured image data. -2 A light cutting line is detected from each.
In the captured image area IA, noise may be included in the image of the bright line LL (bright line image) depending on the imaging performance of the imaging unit 12, or the bright line LL may be captured thickly depending on the pixel structure. The light section line detection unit 23 detects the light section line by obtaining the barycentric position of the luminance from the captured image area IA.
Specifically, the light section line detection unit 23 obtains the coordinate values (i _min , j _min ) to the coordinate values (i _max , j _max ) when the image plane of the captured image area IA is the xy coordinate system plane. gravity position x _c of the luminance in the x-axis direction in the window is calculated by the following equation (1). In equation (1), (x _i , y _j ) is a coordinate value on the image plane, and I (x _i , y _j ) is a luminance value at the coordinate value (x _i , y _j ).

Then, the light section line detecting unit 23 stores a y _c is the position of the y-axis direction corresponding to the position of the gravity center position x _c Toko, barycentric coordinates value in the window (x _{c, y c)} as. Further, the light cutting line detection unit 23 performs light cutting by repeating the process of calculating the equation (1) by zigzag scanning the window in the main scanning direction which is the x-axis direction and the sub-scanning direction which is the y-axis direction. Detect lines.
FIG. 3 is a diagram schematically illustrating how the light section line detection unit 23 performs zigzag scanning of the window in the captured image area IA. In the figure, the window W is a rectangular image area whose width in the x-axis direction is i _max −i _min and whose height in the y-axis direction is j _max −j _min . As shown in the figure, in the captured image area IA, the light section line detection unit 23 moves the window W in a zigzag manner by a predetermined step in the main scanning direction that is the x-axis direction and the sub-scanning direction that is the y-axis direction. Then, the calculation process of Expression (1) is performed for each window W to calculate the barycentric coordinate values (x _c , y _c ), and the light section line is detected from the captured image area IA.

Returning to FIG. 2, the feature point detection unit 24 detects the feature point from the light section line detected by the light section line detection unit 23 in the calibration mode and the normal measurement mode, and calculates the two-dimensional coordinate value of the feature point. get. The feature point is a change point of luminance of the light cutting line, that is, a point at the end of the light cutting line. In FIG. 3, the feature points are points p1 and p2. Therefore, the feature point detection unit 24 acquires the two-dimensional coordinate values of both ends of the light section line detected by the light section line detection unit 23.
FIG. 4 is a diagram illustrating two-dimensional coordinates of feature points detected by the feature point detection unit 24 from the captured image areas IA-1 and IA-2. FIG. 4A shows a bright line LL-1 and two feature points p1a and p2a that are points on both ends of the bright line LL-1 in the picked-up image area IA-1 of the picked-up image picked up by the image pickup unit 12-1. It shows. The two-dimensional coordinate values of the two feature points in the xy coordinate system are p1a = (x1a, y1a) and p2a = (x2a, y2a). FIG. 6B shows the bright line LL-2 in the captured image area IA-2 of the captured image captured by the image capturing unit 12-2 and two feature points p1b and p2b that are points on both ends of the bright line LL-2. It shows. The two-dimensional coordinate values of the two feature points in the x′y ′ coordinate system are p1b = (x1b, y1b) and p2b = (x2b, y2b).

  Note that the feature point detection unit 24 reads a lens distortion correction coefficient (to be described later) from the storage unit and corrects the two-dimensional coordinate value of the image plane in the calibration mode and the normal measurement mode.

Returning to FIG. 2, in the calibration mode, the coordinate conversion parameter calculation unit 25 uses the two-dimensional coordinate values of the xy coordinate system in the captured image area IA-1 of the imaging unit 12-1 and the captured image area of the imaging unit 12-2. A coordinate conversion parameter for converting the two-dimensional coordinate value of the x′y ′ coordinate system in IA-2 into the two-dimensional coordinate value of the xy coordinate system which is a single coordinate system is calculated. Specifically, the coordinate conversion parameter calculation unit 25 is based on an expression representing the surface of the slit light SL, the camera parameter calculated by the camera parameter calculation unit 22, and the height dimension value of the calibration block 100. , A coordinate conversion parameter for associating the xy coordinate system with the x′y ′ coordinate system is calculated and stored in the storage unit.
In the normal measurement mode, the coordinate conversion parameter calculation unit 25 converts the two-dimensional coordinate value of the x′y ′ coordinate system of the feature point of the measurement target object detected by the feature point detection unit 24 into the two-dimensional coordinate system of the xy coordinate system. Linearly transform into coordinate values and integrate them into one xy coordinate system.

  The mounting table drive unit 30 is an actuator that moves or rotates the mounting table 40 based on control information such as a movement direction or a rotation direction, a pitch, a movement distance, or a rotation angle supplied from the measurement control unit 21. For example, a stepping motor It is comprised including.

  Next, the operation in the calibration mode of the three-dimensional shape measuring apparatus 1 will be described. The calibration mode process includes a camera parameter calculation process and a coordinate conversion parameter calculation process. First, camera parameter calculation processing of the three-dimensional shape measuring apparatus 1 will be described. FIG. 5 is a flowchart showing a procedure of camera parameter calculation processing for one imaging unit 12 executed by the three-dimensional shape measurement apparatus 1. After the test chart of the checker pattern is placed on the placing table 40, when the three-dimensional shape measurement apparatus 1 supplies an operation start instruction for camera parameter calculation processing to the measurement control unit 21, the processing of the flowchart shown in FIG. Be started.

In step S1, the measurement control unit 21 controls one image capturing unit 12 (for example, the image capturing unit 12-1) to capture an image of the checker pattern of the test chart. Next, the imaging unit 12 supplies the captured image data to the camera parameter calculation unit 22.
Next, in step S2, the measurement control unit 21 determines whether or not a predetermined number of preset checker patterns have been imaged, and if it is determined that the predetermined number of image captures has not been completed (S2). : NO) proceeds to the process of step S3, and when it is determined that the predetermined number of images have been captured (S2: YES), the process proceeds to step S4.

In step S <b> 3, the measurement control unit 21 controls the mounting table driving unit 30 to rotate the mounting table 40 by a predetermined angle set in advance, for example, in the clockwise direction, and returns to the process of step S <b> 1.
In step S4, when the camera parameter calculation unit 22 acquires a predetermined number of captured image data, the camera parameter calculation unit 22 extracts the two-dimensional coordinate values of the feature points of the checker pattern for each captured image, and associates the extracted feature points with each other. The camera parameters are calculated and stored in the storage unit. And the process of this flowchart is complete | finished.

  The three-dimensional shape measurement apparatus 1 also calculates camera parameters for the imaging unit 12-2 according to the procedure of the flowchart in FIG.

  Here, the camera parameter calculation process of the camera parameter calculation unit 22 will be described. The camera parameter calculation method is disclosed in, for example, “Lerning OpenCV, Computer Vision with the OpenCV Library, Gary Bradski, Adrian Kaebler, O'REILLY”, which is a publicly known document. Calculate camera parameters by technology.

  An outline of camera parameters will be described. Assuming that the two-dimensional coordinate value in the captured image area IA is (xy) and the three-dimensional coordinate value of the world coordinate system that defines the position of the test chart of the checker pattern or the measurement target object is (XYZ), The next coordinate values q (bold body) and Q (bold body) are expressed by equation (2), and the coordinate conversion equation is expressed by equation (3). Note that the description “(bold)” indicates that the character immediately before is bold, and that the data indicated by the character is a matrix or a vector.

In equation (3), s is a scale parameter. M (bold body) is an internal parameter matrix of the imaging unit 12.
The internal parameter matrix M (bold body) includes the following elements.
f _x : Focal length in the x-axis direction (expression in pixel units)
f _y : focal length in the y-axis direction (expressed in pixel units)
c _x : principal point (x coordinate) that is the center of the image
c _y : principal point (y coordinate) that is the center of the image

W (bold body) is an external parameter matrix of the imaging unit 12 and includes the following elements.
R (bold): rotation matrix representing transformation from world coordinates to camera coordinates t (bold): parallel progression representing transformation from world coordinates to camera coordinates Note that the world coordinate is the test chart of the checker pattern first. The coordinates of the position where it was placed.

The camera parameter calculation unit 22 stores in advance a lens distortion correction coefficient for correcting lens distortion of the imaging lens included in the imaging unit 12 and a radius value of the imaging lens in the storage unit. An equation for calculating a two-dimensional coordinate value obtained by correcting lens distortion from a two-dimensional coordinate value in the captured image is, for example, Equation (4). By substituting the two-dimensional coordinate value (x y) of the image plane for (x _d y _d ) in Equation (4), a coordinate value (x y) with corrected lens distortion can be obtained. In Expression (4), k ₁ , k ₂ , and k ₃ are lens distortion correction coefficients indicating the lens distortion in the radial direction of the imaging lens, and p ₁ and p ₂ represent the lens distortion in the circumferential direction of the imaging lens. It is a lens distortion correction coefficient shown. R is the radius of the imaging lens.

  Next, the coordinate conversion parameter calculation process of the three-dimensional shape measuring apparatus 1 will be described. FIG. 6 is a flowchart illustrating a procedure of coordinate conversion parameter calculation processing executed by the three-dimensional shape measurement apparatus 1. After the calibration block 100 is mounted on the mounting table 40, when the three-dimensional shape measurement apparatus 1 supplies an operation start instruction for coordinate conversion parameter calculation processing to the measurement control unit 21, the processing of the flowchart shown in FIG. Is started.

In step S <b> 11, the measurement control unit 21 instructs the light source unit 11 to start irradiation with slit light. And the light source part 11 which received this instruction | indication starts irradiation of slit light SL.
Next, in step S <b> 12, the imaging units 12-1 and 12-2 image the calibration block 100 that is a subject, and supply each captured image data to the optical section line detection unit 23.

  Next, in step S <b> 13, the light section line detection unit 23 takes in the two captured image data, and the bright lines of the bright lines LL appearing on the upper surface 101 of the calibration block 100 in each of the captured image areas IA- 1 and IA- 2. It is determined whether there is an image. Specifically, the light section line detection unit 23 searches, for example, the window W in a zigzag scan for each captured image area IA, and searches for an object with high luminance from the inside of the window W. The light section line detection unit 23 estimates that there is a bright line LL when an object with high luminance is detected. On the other hand, the light section line detection unit 23 estimates that there is no bright line LL when an object with high brightness is not detected. Then, when it is estimated that there is no bright line LL in either one of the captured image areas IA-1 and IA-2, the light section line detection unit 23 determines that the position of the mounting table 40 needs to be adjusted. (S13: YES). On the other hand, the light section line detection unit 23 determines that the adjustment of the position of the mounting table 40 is unnecessary when it is estimated that the bright line LL is present in both the captured image areas IA-1 and IA-2 (S13). : NO).

  When the light section line detection unit 23 determines that the position of the mounting table 40 needs to be adjusted (S13: YES), the light section line detection unit 23 drives the mounting table with respect to the measurement control unit 21 in step S14. The unit 30 is controlled so as to move the mounting table 40 by a predetermined step. And the mounting base drive part 30 moves the mounting base 40 based on the control. The processing from step S12 to step S14 is repeated until the light cutting line detector 23 determines that the adjustment of the position of the mounting table 40 is unnecessary. The moving direction of the mounting table 40 is set in advance so as to move two-dimensionally on the XY plane of the mounting surface.

On the other hand, when the light section line detection unit 23 determines that the adjustment of the position of the mounting table 40 is not necessary (S13: NO), in step S15, the light section line detection unit 23 detects the captured image area IA as described above. -1 and IA-2 are each subjected to processing for obtaining the barycentric position of the luminance, and the light section line is detected.
Next, in step S <b> 16, the feature point detection unit 24 detects a feature point of the light section line obtained from the captured image area IA- 1 and acquires a two-dimensional coordinate value in the xy coordinate system. Then, the feature point detection unit 24 detects the feature point of the light section line obtained from the captured image area IA-2, and acquires the two-dimensional coordinate value of the x′y ′ coordinate system. Next, the feature point detection unit 24 reads a lens distortion correction coefficient from the storage unit, and calculates a two-dimensional coordinate value in which the lens distortion is corrected according to Expression (4).

Next, in step S <b> 17, the coordinate conversion parameter calculation unit 25 calculates coordinate conversion parameters between the xy coordinate system and the x′y ′ coordinate system after the lens distortion correction.
Here, the coordinate conversion parameter calculation processing executed by the coordinate conversion parameter calculation unit 25 will be specifically described. The spread of the slit light SL emitted from the light source unit 11 in the space can be regarded as a surface, and the surface can be expressed as the following equation (5). In Equation (5), A, B, and C are coefficients that define the surface of the slit light, and these coefficients A, B, and C are stored in advance in the storage unit. Z is the height dimension value of the calibration block 100, and this height dimension value is included in the reference data.

  Here, in order to simplify the following description, q (bold body) = s · M (bold body) · W (bold body) · Q (bold body) in equation (3) is expressed by the following equation (6): Replace with

That is, in Equation (6), a 3 × 4 matrix composed of elements of p _ij (1 ≦ i ≦ 3, 1 ≦ j ≦ 4) is expressed as s · M (bold body) · W (bold body). -Corresponds to Q (bold).
When Expression (6) is expanded, the x component of the two-dimensional coordinate value in the captured image area IA is expressed as Expression (7) below.

  Similarly, when Expression (6) is expanded, the y component of the two-dimensional coordinate value in the captured image area IA is expressed as Expression (8) below.

  From the equations (5) and (7), the following equation (9) is derived.

  Similarly, the following equation (10) is derived from the equations (5) and (7).

  The following expression (11) is derived from the expressions (8), (9), and (10).

  As can be seen from the equation (11), the two-dimensional coordinate value (xy) in the captured image area IA is a straight line determined by the camera parameter and the height dimension value of the calibration block 100.

  When the imaging units 12-1 and 12-2 capture the same bright line LL, Expression (9) is expressed as the following Expression (12). In Expression (12), each parameter of the imaging unit 12-1 is given a suffix α, and each parameter of the imaging unit 12-2 is given a suffix β.

If equation (12) will be summarized x ^alpha, becomes the following equation (13).

That is, the coordinate conversion parameter calculation unit 25 can associate the points on each straight line between the xy coordinate system and the x′y ′ coordinate system by linear conversion. K and L in the equation (13) are coordinate transformation parameters. In addition, the coordinate conversion parameter calculation unit 25 obtains y ^α and y ^β corresponding to x ^α and x ^β by Expression (11).
When the equation (13) is arranged, the coordinate conversion parameters K and L are expressed as the following equation (14).

  The coordinate conversion parameter calculation unit 25 stores the coordinate conversion parameters K and L obtained by Expression (14) in the storage unit, and ends the process of the flowchart of FIG.

  The three-dimensional shape measuring apparatus 1 executes a coordinate conversion parameter calculation process shown in FIG. 6 for each of a plurality of calibration blocks 100 having different height dimension values. Then, the coordinate conversion parameter calculation unit 25 stores a coordinate conversion parameter obtained by linear interpolation of the coordinate conversion parameter for each height dimension in the storage unit. By doing in this way, the correspondence of arbitrary height can be obtained simply and in a short time.

  Next, the operation in the normal measurement mode of the three-dimensional shape measurement apparatus 1 will be described. In the normal measurement mode, the imaging units 12-1 and 12-2 respectively capture the measurement target object and supply the captured image data to the light section line detection unit 23. Then, the light section line detection unit 23 takes in these captured image data, and generates a light section line from each of the captured image area IA-1 in the xy coordinate system and the captured image area IA-2 in the x′y ′ coordinate system. To detect. Next, the feature point detection unit 24 acquires the two-dimensional coordinate value of the feature point in the xy coordinate system and the two-dimensional coordinate value of the feature point in the x′y ′ coordinate system. Next, the coordinate conversion parameter calculation unit 25 reads the coordinate conversion parameter from the storage unit, linearly converts the x′y ′ coordinate system to the xy coordinate system, and constructs a virtual image region of the xy coordinate system, and the xy thereof. The two-dimensional coordinate value of the feature point in the coordinate system is stored in the storage unit.

  As described above, according to the three-dimensional shape measurement apparatus 1 according to the first embodiment of the present invention, the coordinate conversion parameter calculation unit 25 is used for calibration in each captured image captured by the imaging units 12-1 and 12-2. A coordinate conversion parameter for converting the two-dimensional coordinate value of the feature point of the light cutting line of the block 100 into the two-dimensional coordinate value of the single coordinate system is calculated. By obtaining these coordinate conversion parameters, the three-dimensional shape measuring apparatus 1 can easily connect the captured images obtained from the imaging units 12-1 and 12-2 having different imaging directions to form a single image plane. Can be built. The calibration block 100 only needs to be placed on the mounting table 40 so that the imaging units 12-1 and 12-2 can respectively capture images. Further, since the calibration does not require detailed scanning of the light section line, the three-dimensional shape measuring apparatus 1 can perform calibration in a short time with a simple operation.

[Second Embodiment]
The second embodiment of the present invention is a form in which the function of the three-dimensional shape measuring apparatus 1 in the first embodiment described above is incorporated in a robot apparatus. In this 2nd Embodiment, about the structure same as 1st Embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

FIG. 7 is a schematic diagram of the robot apparatus and the calibration block schematically showing how the robot apparatus according to the second embodiment of the present invention performs calibration. As shown in the figure, the robot apparatus 2 includes a robot body 50, a light source unit 11, and a mounting table 40. A calibration block 100 is mounted on the mounting table 40.
The robot main body 50 includes a support base 51 fixed to the ground, an arm portion 52 capable of turning and bending, a hand portion 53 capable of rotating and swinging, and an imaging unit 12 attached to the hand portion 53. It is comprised including. The robot body 50 is an inspection robot in which the combination of the support base 51, the arm unit 52, and the hand unit 53 has six degrees of freedom, and the position and orientation of the imaging unit 12 can be freely changed.
The robot body 50 may have three or more degrees of freedom. Moreover, you may install the support stand 51 in the place fixed with respect to the grounds, such as a wall and a ceiling other than the ground.

  Next, the functional configuration of the three-dimensional shape measuring apparatus 1 will be described. FIG. 8 is a block diagram illustrating a main functional configuration of the robot apparatus 2. In the figure, the same components as those shown in FIG. As shown in FIG. 8, the robot apparatus 2 includes a light source unit 11, a control unit 20 a, a mounting table driving unit 30, a mounting table 40, and a robot body 50. Hereinafter, the functional configuration of the robot apparatus 2 will be described with reference to FIGS. 7 and 8 together.

  The control unit 20a controls the entire robot apparatus 2, and performs, for example, control for switching between a calibration mode and a normal measurement mode by a selection signal supplied from the outside. The control unit 20a includes a CPU (Central Processing Unit) and a storage unit (both not shown), and in terms of its functions, the measurement control unit 21a, the camera parameter calculation unit 22a, and the light section line detection unit 23a. And a feature point detection unit 24 and a coordinate conversion parameter calculation unit 25.

The measurement control unit 21 a controls the light source unit 11, the mounting table driving unit 30, and the robot body 50. Specifically, the measurement control unit 21a controls the light source unit 11 to start and stop the emission of the slit light SL. The measurement control unit 21a controls the imaging unit 12 to image a checker pattern test chart and supply the captured image data to the camera parameter calculation unit 22a. In addition, the measurement control unit 21a controls the imaging unit 12 to capture the bright line LL reflected in the measurement target object and supply the captured image data to the light section line detection unit 23a. Further, the measurement control unit 21a moves the mounting table 40 in at least one of the X direction and the Y direction on the mounting surface with respect to the mounting table driving unit 30, or uses the approximate center position of the mounting surface as a central point. Control which rotates the mounting base 40 is performed. In addition, the measurement control unit 21a operates the support base 51, the arm unit 52, and the hand unit 53 in a complex manner with respect to the robot main body 50 so that the imaging unit 12 is moved to the first position and the second position in the three-dimensional space. Can be set to position.
Note that the first and second positions include changing the direction of the optical axis of the imaging lens of the imaging unit 12.

In the calibration mode, the camera parameter calculation unit 22a captures captured image data supplied from the imaging unit 12, and based on the two-dimensional coordinate values of the checker pattern included in the captured image for each position and orientation of the imaging unit 12. Perform camera calibration.
The light section line detection unit 23a sequentially captures the captured image data supplied from the imaging unit 12 in the calibration mode and the normal measurement mode, and the captured image area IA- of the captured image data for each position and orientation of the imaging unit 12. 1 and IA-2 detect the optical cutting line. The captured image area of the captured image data captured at the first position of the imaging unit 12 is the captured image area IA-1, and the captured image area of the captured image data captured at the second position of the imaging unit 12 Is the captured image area IA-2.

  Next, the operation in the calibration mode of the robot apparatus 8 will be described. The calibration mode process includes a camera parameter calculation process and a coordinate conversion parameter calculation process. First, camera parameter calculation processing of the robot apparatus 2 will be described. The procedure of the camera parameter calculation process for the imaging unit 12 executed by the robot apparatus 2 is the same as the procedure according to the flowchart shown in FIG. 5 described in the first embodiment. Therefore, the procedure of the camera parameter calculation process for the imaging unit 12 executed by the robot apparatus 2 will be described with reference to FIG. After the test chart of the checker pattern is placed on the placing table 40, when the robot apparatus 2 supplies an operation start instruction for camera parameter calculation processing to the measurement control unit 21a, the processing of the flowchart shown in FIG. .

In step S1, the measurement control unit 21a controls the imaging unit 12 set to the first position to image the checker pattern of the test chart. Next, the imaging unit 12 supplies the captured image data to the camera parameter calculation unit 22.
Next, in step S2, the measurement control unit 21a determines whether or not a predetermined number of checker patterns that have been set in advance have been imaged, and determines that the predetermined number of images has not been captured (S2). : NO) proceeds to the process of step S3, and when it is determined that the predetermined number of images have been captured (S2: YES), the process proceeds to step S4.

In step S3, the measurement control unit 21a controls the mounting table driving unit 30 to rotate the mounting table 40 by a predetermined angle set in advance, for example, in the clockwise direction, and returns to the process of step S1.
In step S4, when the camera parameter calculation unit 22 acquires a predetermined number of captured image data, the camera parameter calculation unit 22 extracts the two-dimensional coordinate values of the feature points of the checker pattern for each captured image, and associates the extracted feature points with each other. The camera parameters are calculated and stored in the storage unit. And the process of this flowchart is complete | finished.

The robot apparatus 2 calculates camera parameters for the imaging unit 12 set at the second position in accordance with the procedure of the flowchart of FIG.
Note that the camera parameter calculation process of the camera parameter calculation unit 22 is the same as that of the first embodiment, and thus the description thereof is omitted.

  Next, the coordinate conversion parameter calculation process of the robot apparatus 2 will be described. FIG. 9 is a flowchart illustrating a procedure of coordinate conversion parameter calculation processing executed by the robot apparatus 2. After the calibration block 100 is mounted on the mounting table 40, when the robot apparatus 2 supplies an operation start instruction for coordinate conversion parameter calculation processing to the measurement control unit 21a, the processing of the flowchart shown in FIG. The

In step S31, the measurement control unit 21a instructs the light source unit 11 to start irradiation of slit light. And the light source part 11 which received this instruction | indication starts irradiation of slit light SL.
Next, in step S32, the measurement control unit 21a controls the robot main body 50 so as to set the imaging unit 12 to the first position. Then, the robot main body 50 controls the support base 51, the arm unit 52, and the hand unit 53 to set the imaging unit 12 to the first position. Next, the imaging unit 12 images the calibration block 100 that is a subject, and supplies the captured image data to the light section line detection unit 23a.
Next, the measurement control unit 21a controls the robot body 50 so as to set the imaging unit 12 to the second position. Then, the robot body 50 controls the support base 51, the arm unit 52, and the hand unit 53 to set the imaging unit 12 to the second position. Next, the imaging unit 12 images the calibration block 100 that is a subject, and supplies the captured image data to the light section line detection unit 23a.

  Next, in step S <b> 33, the light section line detection unit 23 sequentially captures the captured image data, and the bright line images of the bright lines LL displayed on the upper surface 101 of the calibration block 100 in each of the captured image areas IA-1 and IA-2. It is determined whether or not there is. The specific content of the estimation method for determining whether there is a bright line LL is the same as that in the first embodiment, and thus the description thereof is omitted. When it is estimated that the bright line LL is not present in either one of the captured image areas IA-1 and IA-2, the light section line detection unit 23a determines that the position of the mounting table 40 needs to be adjusted (S33). : YES) On the other hand, when it is estimated that the bright line LL exists in both the captured image areas IA-1 and IA-2, the light section line detection unit 23a determines that the adjustment of the position of the mounting table 40 is unnecessary (S33). : NO).

  When the light section line detection unit 23a determines that the position of the mounting table 40 needs to be adjusted (S33: YES), in step S34, the light section line detection unit 23a drives the mounting table with respect to the measurement control unit 21a. The unit 30 is controlled so as to move the mounting table 40 by a predetermined step. And the mounting base drive part 30 moves the mounting base 40 based on the control. The processing from step S32 to step S34 is repeated until the light cutting line detection unit 23a determines that the adjustment of the position of the mounting table 40 is unnecessary. The moving direction of the mounting table 40 is set in advance so as to move two-dimensionally on the XY plane of the mounting surface.

On the other hand, when the light section line detection unit 23a determines that the adjustment of the position of the mounting table 40 is unnecessary (S33: NO), in step S35, the light section line detection unit 23a, as described above, the captured image area IA. -1 and IA-2 are each subjected to processing for obtaining the barycentric position of the luminance, and the light section line is detected.
The processing of the next step S36 and step S37 is the same as the processing of step S16 and step S17 of the coordinate transformation parameter calculation processing in the first embodiment shown in FIG.

  The robot apparatus 2 executes the coordinate conversion parameter calculation process shown in FIG. 9 for each of the plurality of calibration blocks 100 having different height dimension values. Then, the coordinate conversion parameter calculation unit 25 performs linear interpolation on the coordinate conversion parameter for each height dimension, calculates a coordinate conversion parameter corresponding to the height dimension, and stores it in the storage unit.

  Next, the operation in the normal measurement mode of the robot apparatus 2 will be described. In the normal measurement mode, the measurement control unit 21a controls the robot main body 50 so as to set the imaging unit 12 to the first position. Then, the robot main body 50 controls the support base 51, the arm unit 52, and the hand unit 53 to set the imaging unit 12 to the first position. Next, the imaging unit 12 images the measurement target object and supplies the captured image data to the light section line detection unit 23a. Next, the measurement control unit 21a controls the robot body 50 so as to set the imaging unit 12 to the second position. Then, the robot body 50 controls the support base 51, the arm unit 52, and the hand unit 53 to set the imaging unit 12 to the second position. Next, the imaging unit 12 images the measurement target object and supplies the captured image data to the light section line detection unit 23a.

  The light section line detection unit 23a sequentially captures captured image data, and detects a light section line from each of the captured image area IA-1 in the xy coordinate system and the captured image area IA-2 in the x′y ′ coordinate system. Next, the feature point detection unit 24 acquires the two-dimensional coordinate value of the feature point in the xy coordinate system and the two-dimensional coordinate value of the feature point in the x′y ′ coordinate system. Next, the coordinate conversion parameter calculation unit 25 reads the coordinate conversion parameter from the storage unit, linearly converts the x′y ′ coordinate system to the xy coordinate system, and constructs a virtual image region of the xy coordinate system, and the xy thereof. The two-dimensional coordinate value of the feature point in the coordinate system is stored in the storage unit.

  As described above, according to the robot apparatus 2 according to the second embodiment of the present invention, the coordinate transformation parameter calculation unit 25 uses the light of the calibration block 100 in each captured image captured by the imaging unit 12 at two positions. A coordinate conversion parameter for converting the two-dimensional coordinate value of the feature point of the cutting line into the two-dimensional coordinate value of the single coordinate system is calculated. By obtaining the coordinate conversion parameters, the robot apparatus 2 can easily connect the captured images sequentially obtained from the imaging units 12 with different imaging positions to construct a single image plane. The calibration block 100 need only be placed on the mounting table 40 so that the imaging unit 12 can capture images at two positions. Further, since the calibration does not require detailed scanning of the light section line, the robot apparatus 2 can perform calibration in a short time with a simple operation.

In the first and second embodiments described above, the calibration block 100 has a plurality of different distances (height dimensions) between the placement surface of the placement table 40 and the upper surface 101 of the calibration block 100. One of the solid blocks. In addition to this, for example, a solid block provided with a plurality of planes having different height dimensions may be used.
FIG. 10 is a perspective view of the appearance of a calibration block provided with a plurality of planes having different height dimensions. As shown in the figure, the calibration block 200 is integrally formed with four steps. Note that the number of steps is not necessarily four, but may be a plurality of steps. The calibration block 200 may be hollow or concave. The calibration block 200 is mounted with its bottom 201 aligned with the mounting surface of the mounting table 40, and the bottom 201 has a surface or at least four support portions in order to ensure stability of installation. Have. Stepped planes 202a to 202d that are parallel to the mounting surface of the bottom 201 and have different vertical dimensions are provided on the step-shaped portion opposite to the bottom 201.
When the calibration block 100 is used, replacement work of the calibration block 100 by the operator occurs. However, when the calibration block 200 is used, such replacement work does not occur and the workability is improved. be able to.

  Further, the checker pattern may be patterned on the upper surface 101 of the calibration block 100 or at least one of the step planes 202a to 202d of the calibration block 200. In this way, the calibration blocks 100 and 200 can be used instead of the checker pattern test chart for obtaining the camera parameters, and workability can be improved.

  In the first embodiment, the example using two imaging units 12 (imaging units 12-1 and 12-2) has been described. However, the number of imaging units 12 is not limited to this, and a plurality of imaging units 12 may be applied. Can do. For example, when three imaging units 12 (imaging units 12-1, 12-2, 12-3) are used, calibration is performed for the two imaging units 12-1, 12-2 in the same manner as in the first embodiment. Further, the same calibration as that of the first embodiment is performed for the two imaging units 12-2 and 12-3. Thereby, the imaging units 12-1, 12-2, and 12-3 can be associated with each other.

  Moreover, although 2nd Embodiment demonstrated the example which sets the imaging part 12 to two types of positions and directions, it is not limited to this, It can also set to more positions and directions. For example, when three types of positions and orientations are set, the first and second positions are calibrated in the same manner as in the second embodiment, and the second and third positions are set in the second implementation system. Perform the same calibration as the value sub. Thereby, the imaging part 12 set to the 1st-3rd position can be matched.

  In addition, you may make it implement | achieve the function of a part of three-dimensional shape measuring apparatus which is embodiment mentioned above, for example, a control part with a computer. In this case, a calibration program for realizing the control function is recorded on a computer-readable recording medium, and the calibration program recorded on the recording medium is read by the computer system and executed. May be. Here, the “computer system” includes an OS (Operating System) and hardware of peripheral devices. The “computer-readable recording medium” refers to a portable recording medium such as a flexible disk, a magneto-optical disk, an optical disk, and a memory card, and a storage device such as a hard disk built in the computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case may be included and a program that holds a program for a certain period of time may be included. Further, the above program may be for realizing a part of the functions described above, or may be realized by a combination with the program already recorded in the computer system. .

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design etc. of the range which does not deviate from the summary of this invention are included.

DESCRIPTION OF SYMBOLS 1 Three-dimensional shape measuring apparatus 2 Robot apparatus 10 Optical measurement part 11 Light source part 12, 12-1, 12-2 Imaging part 20, 20a Control part 21, 21a Measurement control part 22 Camera parameter calculation part 23, 23a Light cutting line detection Unit 24 feature point detection unit 25 coordinate conversion parameter calculation unit 30 mounting table driving unit 40 mounting table 50 robot body 51 support table 52 arm unit 53 hand unit 100, 200 calibration block 201 bottom 202a, 202b, 202c, 202d Plane IA, IA-1, IA-2 Captured image area LL, LL-1, LL-2 Bright lines p1, p2 points p1a, p2a, p1b, p2b Feature points SL Slit light W Window

Claims (5)

In the three-dimensional shape measuring apparatus in which a plurality of imaging units pick up the light cutting line reflected in the slit light irradiation part emitted by the light source unit and measure the three-dimensional shape,
A calibration block;
A light cutting line detection unit that detects a light cutting line by the slit light emitted to the calibration block from a plurality of captured images captured by the plurality of imaging units, and
A feature point detection unit that detects coordinate values of feature points from a plurality of light cutting lines respectively detected by the light cutting line detection unit;
Based on the equation representing the surface of the slit light, the camera parameters of each of the plurality of imaging units, and the height dimension value of the calibration block, the coordinate value of the feature point in each of the plurality of captured images is a single value. A coordinate conversion parameter calculation unit for calculating a coordinate conversion parameter for converting to a coordinate value of the coordinate system;
A three-dimensional shape measuring apparatus comprising:   The calibration block has a plane on which the slit light is to be irradiated, and is provided so that the plane is parallel to a calibration reference plane of the three-dimensional shape measuring apparatus. 3. The three-dimensional shape measuring apparatus according to 1. The coordinate transformation parameter calculating section claims wherein in response to the calibration for a plurality of height values of the block are calculated a plurality of coordinate conversion parameters, characterized by linearly interpolating the plurality of coordinate conversion parameters The three-dimensional shape measuring apparatus according to 1 or 2 . In a calibration method of a three-dimensional shape measuring apparatus in which a plurality of imaging units pick up a light cutting line reflected in an irradiation portion of slit light emitted from a light source unit and measure a three-dimensional shape,
A light cutting line detection step for detecting a light cutting line by the slit light emitted to the calibration block from a plurality of captured images captured by the plurality of imaging units, respectively;
A feature point detection step of detecting coordinate values of feature points from the plurality of light cutting lines detected in the light cutting line detection step;
Based on the equation representing the surface of the slit light, the camera parameters of each of the plurality of imaging units, and the height dimension value of the calibration block, the coordinate value of the feature point in each of the plurality of captured images is a single value. A coordinate conversion parameter calculation step for calculating a coordinate conversion parameter for converting to a coordinate value of the coordinate system;
A method for calibrating a three-dimensional shape measuring apparatus, comprising: In the robot apparatus in which the imaging unit images the light cutting line reflected in the slit light irradiation part emitted from the light source unit and performs the three-dimensional shape measurement,
A calibration block;
A hand unit to which the imaging unit is attached;
An arm part to which the hand part is movably attached;
A measurement control unit that operates the hand unit and the arm unit in combination to change the position of the imaging unit, and causes the imaging unit to image at the changed position;
A light cutting line detection unit that detects a light cutting line by the slit light emitted to the calibration block from a plurality of captured images captured by the plurality of imaging units, and
A feature point detection unit that detects coordinate values of feature points from a plurality of light cutting lines respectively detected by the light cutting line detection unit;
Based on the equation representing the surface of the slit light, the camera parameters of each of the plurality of imaging units, and the height dimension value of the calibration block, the coordinate value of the feature point in each of the plurality of captured images is a single value. A coordinate conversion parameter calculation unit for calculating a coordinate conversion parameter for converting to a coordinate value of the coordinate system;
A robot apparatus comprising:

Images