JPH0481124B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a three-dimensional measurement method for non-contact measurement of the position of a three-dimensional surface of a human body, an object, etc.

[Prior art]

Conventionally, methods for measuring the three-dimensional shape of a human body or an object include contact methods, in which a sensing probe is brought into contact with the object to be measured, and non-contact methods, such as stereo photography, moiré topography, and light sectioning. These methods are used for industrial robots,
It is widely applied as an object recognition technology for various inspection devices.

In the case of the contact method, only objects to be measured that can be touched can be measured, which limits the number of objects that can be measured.Also, since the position of each point on the surface of the object is measured by contact, the measurement time is significantly longer. It takes time.

Therefore, it is desirable to measure the shape of the object to be measured without contacting the object, as in the non-contact method described above.

[Problems to be Solved by the Invention] However, in the case of the conventional non-contact method, the position of each point on the three-dimensional surface to be measured is calculated based on shape recognition of the object to be measured. To measure the position of each point on a three-dimensional surface, it is necessary to determine the target measurement point from the obtained shape information and calculate the two-dimensional or three-dimensional position of the determined measurement point. There are problems in that it is necessary to perform complex calculation processing such as case function calculations, and the calculation takes time.

In addition, the measuring devices that implement both of the above methods have very low resolution, and if the object to be measured is small or the surface of the object to be measured is uneven, measurement errors may increase or measurements may not be possible.
There is a problem of lack of reliability.

[Means for solving problems]

In this invention, a three-dimensional object to be measured is placed on a horizontal support stand on a base, a plurality of pillars are erected around the base, and a horizontal linear slit light is emitted to each of the pillars. a non-contact measuring instrument having a light projecting means for irradiating the three-dimensional object and a pair of imaging means for capturing images of the irradiated portion of the three-dimensional object from two directions, above and below the light projecting means, is mounted so as to be vertically movable; While moving each of the measuring instruments in the vertical direction, the horizontal direction and the vertical direction are three-dimensional, with the Z-axis direction and the The position of point G (x, y, z) of the irradiated part in the coordinates is x = (d-Kx)・{L/L+(de-e)-1}+d y=Ky・L/L+(d- e) z=Kz・r d and e are the X of point G at each of the pair of imaging outputs
Axial distance data L is the distance Kx, Ky between the pair of imaging means in the X-axis direction
are coefficients in the X-axis direction and Y-axis direction that are set based on the lens magnification and position of the pair of imaging means. r is the scanning line number of point G in the pair of imaging outputs. Kz is the number of scanning lines. This is a three-dimensional measurement method characterized by calculating and measuring each position on the surface of the three-dimensional object by calculating the four arithmetic operations of coefficients determined by the width and lens magnification.

[Operation] Then, the light emitting means of each measuring instrument illuminates the circumferential surface of the solid body with horizontal slit light so as to surround the solid body, and the vertical movement of each measuring device causes the irradiation position of each slit light to move vertically. Moving.

Furthermore, the irradiated portion of each slit light is imaged by a pair of imaging means of each measuring device from two directions, above and below the light projecting means, and the slit light in each pair of imaging outputs obtained by this imaging is By simple arithmetic operations based on the position information, the position of each point on the irradiated portion of each slit light is calculated, and each position on the surface of the three-dimensional object is measured.

〔Example〕

Next, the present invention will be described in detail with reference to drawings showing one embodiment thereof.

First, in FIG. 1 showing the measuring device, 1 is a base, 2 is a horizontal support placed on the base 1, and 3 is a horizontal support stand placed on the base 1.
are the three-dimensional object to be measured placed on the support stand 2, 4a,
4b, 4c, and 4d are four columns erected at the four corners of the base 1, and the inner surfaces of the columns 4a and 4c face each other via the solid body 3, and the columns 4
The inner surfaces of b and 4d face each other with the solid body 3 in between.

5a, 5b, 5c, and 5d are four connecting rods, and each of the pillars 4a to 4a is provided between adjacent pillars 4a and 4b, 4b and 4c, 4c and 4d, and 4d and 4a.
Fix 4d. Racks 6a, 6b, 6c, and 6d are provided vertically on the inner surfaces of the respective pillars 4a to 4d.

7a, 7b, 7c, 7d are each rack 6a to 6d
These are four non-contact measuring instruments each equipped with a pinion that meshes with the support pillars 4a to 7d.
The pillars 4a to 4 move up and down along the pillars 4d.
d so that it can move up and down.

Reference numeral 8 denotes a light projecting means provided in each of the measuring instruments 7a to 7d, which irradiates the three-dimensional object 3 with linear slit light parallel to the plane of the support base 2, that is, in the horizontal direction. If the positions in the height direction of ~7d are equal, the slit light is uniformly irradiated onto a predetermined height portion of the entire circumferential surface of the solid body 3, as shown by the broken line in FIG.

Reference numerals 9α and 9β denote a pair of imaging means provided in each of the measuring instruments 7a to 7d, which are composed of a two-dimensional sensor device such as a CCD type area image sensor device. The other imaging means 9β is located below the light projecting means 8. Reference numeral 10 indicates a leg mounted near the solid body 3 of the support base 2, and reference numeral 11 indicates a cylindrical measurement reference gauge erected on the leg 10.

The light projecting means 8 and the imaging means 9α, 9β of each of the measuring instruments 7a to 7d are constructed as shown in FIG. A light source outputs light, 12b is an expansion lens made of a convex tube lens or the like that increases the length of the slit light from the light source 12a, 12c is a reflecting mirror, and lens 1
The surface of the solid body 3 is irradiated with horizontal linear slit light from the light source 12a via the light source 12b.

13αa and 13βa are light receiving elements, respectively.
An image sensor formed by arranging CCDs in a two-dimensional matrix of M rows vertically and N columns horizontally, 13αb, 1
3βb is the reflected light from the surface of the solid body 3.
The imaging sensor 13βa and the lens 13βb form one imaging means 9α, and the imaging sensor 13
The other imaging means 9β is formed by βa and the lens 13βb.

By the way, in order to explain the measurement position in the XYZ three-dimensional coordinate system, as shown in Figure 2, the vertical direction in Figure 1 is taken as the X-axis direction, and the irradiation direction of the slit light is parallel to the irradiated slit light. The Y-axis direction is taken as the Y-axis direction, and the Z-axis direction is taken respectively.

Note that both the imaging means 9α and 9β are fixedly set above and below the light projecting means 8 so that the portion of the solid body 3 irradiated with the slit light is located within the imaging field of view.

Further, S in FIG. 2 indicates the slit light irradiated onto the solid body 3.

And the imaging sensor 13 of both imaging means 9α, 9β
The slit light irradiated portion of the solid 3 is imaged by αa, 13βa, and at this time both image sensors 13αa,
On the imaging surfaces Fα and Fβ of 13βa, slit light images Sα and Sβ are formed in the vertical direction, as shown in FIGS. Only the part becomes brighter.

Furthermore, one each of both image sensors 13αa and 13βa
Both image sensors 1
Imaging outputs of one scanning line each of 3αa and 13βa are formed, and the imaging outputs of each scanning line are sequentially output from both imaging means 9α and 9β.

Note that the horizontal direction in FIGS. 3a and 3b corresponds to the X-axis direction, and the vertical direction corresponds to the Z-axis direction, and the horizontal lines A ₁ , ..., Am, Am ₊₁ , Am in FIG. ₊₂ ,
Am ₊₃ ,..., An indicate the first to Nth scanning lines of the image sensor 13αa, and horizontal lines B ₁ ,..., Bm, Bm ₊₁ , Bm ₊₂ , Bm ₊₃ , ..., Bn
denotes the first to Nth scanning lines of the imaging sensor 13βa, and the imaging outputs of the respective scanning lines of both sensors 13αa and 13βa are sequentially read out at the same timing.

A pair of analog imaging outputs read from both imaging sensors 13αa and 13βa of each of the measuring instruments 7a to 7d are sent to an electronic computer 14 shown in FIG.
are respectively input to image processing means for each of the measuring instruments 7a to 7d provided in the.

Each image processing means is constructed as shown in FIG. 5, in which 15 is a clock circuit that generates a clock signal, 16α and 16β are a pair of signal processing circuits, and both image pickup means 9α and 9β are connected to each other. Analog imaging outputs of each scanning line sequentially outputted from the imaging sensors 13αa, 13αa are captured at the timing of the clock signal, and sliced at a predetermined slice level to create slit optical images Sα,
A digital image signal is formed in which only the Sβ portion is at a high level.

17α and 17β are a pair of address counters, and both image sensors 1 are
Both processing circuits 1 are processed by slit light images Sα and Sβ from the reference point position at the left end of each scanning line of 3αa and 13βa.
1 of both image sensors 9α and 9β up to the point where the digital image signals of 6α and 16β become high-level pulses.
Count the distances in the pair of image outputs,
Distance data in the X-axis direction of each point of the irradiated portion in each of the pair of imaging outputs is output.

18 is an arithmetic circuit, and both counters 17α, 1
A pair of distance data in the X-axis direction simultaneously input from 7β, data in the Z-axis direction at each point in the irradiation area, consisting of a scanning line number obtained by counting clock signals and a preset scanning line width. The position of each point in the slit light irradiation area in the three-dimensional coordinate system is calculated from the four arithmetic operations described below based on the position information of the slit light.

19 is a storage unit that stores the coordinate position of each point of the irradiated portion calculated by the arithmetic circuit 18; 20 is a processing circuit 16α, 16β; counters 17α, 17β;
An image processing means consisting of an arithmetic circuit 18 and a storage section 19; 21 is a display condition setting section; 22 is a recognition circuit; based on the conditions set in the setting section 21, the coordinate position of each point stored in the storage section 19 is from solid 3
The coordinate position of each point stored in the storage section 19 and a display signal indicating the identified dimensions, surface condition, shape, etc. are output to the display means 23 in FIG. 4.

As shown in FIG. 2, linear slit light is emitted from the light projecting means 8, and the irradiated portion of the slit light S is directed in two directions by the upper and lower imaging means 9α and 9β of the light projecting means 8. For example, slit light images Sα and Sβ shown in FIGS. 3a and 3b are formed on both imaging means 9α and 9β, respectively.

Further, the first scanning line A 1 to the Nth scanning line A ₁ to Nth
The imaging outputs of the scanning lines An are sequentially output, and for example, as shown in FIG.
When the imaging outputs of Am, Am ₊₁ , Am ₊₂ , and Am ₊₃ are sequentially output, at the same time, from the image sensor 13βa of the imaging means 9β to the processing circuit 16β.
Then, as shown in FIG. 7a, the imaging outputs of the Mth to M+3 scanning lines Bm, Bm ₊₁ , Bm ₊₂ and Bm ₊₃ are sequentially output.

The processing circuits 16α and 16β sequentially slice the analog imaging outputs for each scanning line from the image sensors 13αa and 13βa at a slice level l, and at this time, the level l is the slit light image Sα,
Since the level is set to extract only the Sβ portion, only the slit light image Sα and Sβ portions in each scanning line output are extracted, as shown in Figures 6b and 7b. The imaging outputs of the means 9α and 9β are digitally converted.

Then, the digital signals of both processing circuits 16α and 16β are inputted to both counters 17α and 17β, respectively, and the counters 17α and 17β, as shown in FIG. 6c and FIG _{. Each} reference point pulse is formed at the timing of
am, am ₊₁ , am ₊₂ , am ₊₃ and bm, bm ₊₁ ,
Distance to bm ₊₂ , bm ₊₃ respectively Dam, Dam ₊₁ ,
Dam ₊₂ , Dam ₊₃ and Dbm, Dbm ₊₁ ,
Count Dbm ₊₂ and Dbm ₊₃ , and slit light image Sα
Distance data in the X-axis direction and slit light image Sβ
The distance data in the X-axis direction is output to the arithmetic circuit 18.

Next, the calculation of the calculation circuit 18 will be explained.

Now, to simplify the explanation, both imaging means 9
The imaging fields of α and 9β are set to be completely equal, and the left end of the imaging field of view is set to coincide with the Z axis.
As shown in the figure, a point G on the irradiated part of the slit light S
The light of (x, y, z) reaches the center point P(a, ₀ , z) of the lenses 13αb, 13βb of both imaging means 9α, 9β,
If the image is formed through Q(b, ₀ , z), then the image forming point and the center point P(a, ₀ , z), Q(b, ₀ ,
z) Each line segment connecting Y-axis solid (object to be measured)
Point U that intersects the XZ plane passing through any point c on the side
By setting (d, c, z), V (e, c, z), point G (x, y, z) becomes point P (a, ₀ , z),
A line segment passing through U (d, c, z) and point Q (b, ₀ , z),
It is found as the intersection with the line segment passing through V(e, c, z).

And the points P(a, ₀ , z), Q(b, ₀ , z), U(d
,
Based on the values of c, z) and V(e, c, z), point G
The X and Y axis components x and y of (x, y, z) are as follows
It can be found from equations (1) and (2).

x=a・e−b・d/a−b−d+e=b・d−a・e
/b-a+d-e = (d-a) {b-a/b-a+d-e-1}+d...(1) Formula y=c・(a-b)/a-b-d+e=c・(b-
a)/b-a+d-e......(2) By the way, b-a in equations (1) and (2) represents both image sensors 1
3αa and 13βa are the distances L, and d and e are the magnifications of the lenses 13αb and 13βb and the imaging means 9α and 9
This is the position of point G (x, y, z) in the X-axis direction on the imaging planes Fα, Fβ determined by the mounting position of β.

Then, d and e are obtained as distance data from the reference point d ₀ at the left end of each of the imaging planes Fα and Fβ.

Further, a, b, and c are constants set by the mounting positions of the imaging means 9α and 9β, the magnifications of the lenses 13αb and 13βb, and the like.

Therefore, by setting constants a and c in the X and Y axis directions, which are set based on the magnification of the lenses 13αb and 13βb and the positions of the imaging means 9α and 9β, as Kx and Ky, the point G (x, y, z )'s X and Y axis components x,
y can be found by calculating the following equations (3) and (4).

x=(d-Kx)・{L/L+(d-e)-1}+d...Formula (3) y=Ky・L/L+(d-e)...Formula (4) On the other hand, point G( The Z-axis component z of the point G (x, y, z) is based on the scanning line number r of the point G (x, y, z), and the coefficient Kz determined by the number and width of the scanning lines and the magnification of the lenses 6a and 6b. It can be found by calculating the following equation (5).

z=Kz・r...Equation (5) Then, Kx, Ky, L in Equations (3) and (4) and Kz in Equation (5) are constants, and d and e are the counters 17α,
Since r is obtained as a pair of distance data in the X-axis direction input from 17β, and r is obtained by counting the clock signal, the arithmetic circuit 18 calculates Based on the position information of the slit light, which consists of the set position information consisting of the set position information, a pair of distance data input from the counters 17α and 17β, and the detected position information consisting of the count data of the clock signal, the four rules of equations (3) to (5) are determined. By performing calculations to calculate the position of point G (x, y, z) and applying the calculation to each point in the slit light irradiation area, the second figure of each point in the slit light irradiation area is calculated. Calculate the three-dimensional position of in the XYZ coordinate system.

In addition, when the fields of view of both imaging means 9α and 9β do not completely overlap, and when the vertical and horizontal directions of the imaging planes Fα and Fβ are misaligned with the Z and X axes, the amount of misalignment is added to the value of each formula. The three-dimensional position of each point in the slit light irradiation area is calculated by multiplying by a correction coefficient corresponding to .

When each of the measuring instruments 7a to 7d moves up and down along each of the pillars 4a to 4d by the drive of a built-in motor, the horizontal slit light irradiated from each of the measuring instruments 7a to 7d onto the surface of the solid 3 is emitted from the bottom to the top or The arithmetic circuit 18 calculates the three-dimensional position of each point of the slit light irradiation part at each irradiation position, changing sequentially from top to bottom.
Accordingly, the position of each point on the surface of the solid body 3 is calculated and measured.

By the way, the origin of the XYZ coordinate system in FIG. 2 is a different point for each of the measuring instruments 7a to 7d, and as each measuring instrument 7a to 7d moves up and down the supports 4a to 4d, the origin of each measuring instrument 7a to 7d is set to a different point. changes as it moves on the X-axis, the X-axis component axis components y, z
Only the two-dimensional position of the object can be measured.

However, if a reference point in the X-axis direction that does not change when the measuring instruments 7a to 7d move up and down is set, the X-axis component x is calculated and the position on the XYZ three-dimensional coordinate system is measured.

Therefore, when calculating and measuring a three-dimensional position instead of a two-dimensional position, one of the following first and second methods using the gauge 11 is used.

First, in the first method, each measuring device 7a is
The initial positions of the measuring devices 7a to 7d in the X-axis direction, that is, the vertical direction before measurement, are measured from the positions of the scales of the gauges 11 imaged by the images taken by the measuring devices 7a to 7d. This is the position of the reference point in the axial direction.

After setting the position of the reference point in the X-axis direction, each measuring device 7a to 7d is moved up and down, and the four arithmetic operations based on the above-mentioned formulas (3) to (5) are performed to determine the X, Y , calculates the Z-axis components x, y, and z, and adds and subtracts the amount of movement of each measuring device 7a to 7d from the reference point to the calculated X-axis component x to set the X-axis component x to the reference point. , and the X-axis direction is calculated and measured on three-dimensional coordinates having the same reference point.

Next, in the second method, each measuring device 7
Based on the positions of the scales imaged by a to 7d, the vertical positions of all measuring devices 7a to 7d are corrected to, for example, the position of the lowest scale point of the gauge 11,
The reference points of all measuring instruments 7a to 7d in the X-axis direction are aligned at the same position, and the initial positions of all measuring instruments 7a to 7d are set within the same YZ plane.

After aligning the reference points in the X-axis direction,
All measuring instruments 7a to 7d are sequentially moved up and down by the same amount at the same timing, and the above-mentioned (3) or
(5) By performing four arithmetic operations based on formula,
In addition to calculating the Y and Z axis components x, y, and z, the X axis component is corrected by adding and subtracting the amount of movement from the reference point to the calculated X axis component x, and in the X axis direction, Calculate and measure on a three-dimensional coordinate system with the same reference point.

Furthermore, a standard three-dimensional coordinate system having true reference points of the X, Y, and Z axes is set inside the solid body 3, and each measuring instrument 7a is
By converting the origin of the three-dimensional coordinate system of ~7c to the origin of the reference three-dimensional coordinate system, the measuring instrument 7
The calculated positions for each of a to 7d are converted to positions on the reference three-dimensional coordinate system, and thereby the three-dimensional position of each point on the surface of the solid 3 is measured in the absolute three-dimensional coordinate system. be done.

Note that the coordinate transformation is performed, for example, by measuring instruments 7a to 7.
By calculating in advance a correction coefficient for changing the origin of the three-dimensional coordinate system for each d to the origin of the reference three-dimensional coordinate system, this can be done using only four arithmetic operations.

Therefore, the computer 14 calculates the position of each measuring device 7a to 7d in the three-dimensional coordinate system calculated by each image processing means 20 using the first or second method by four arithmetic operations of coordinate transformation. It is converted to a position on a reference three-dimensional coordinate system, and the position of each point on the surface of the solid 3 is calculated and measured using the reference three-dimensional coordinate system.

Furthermore, based on the calculated coordinate position of each point on the surface of the solid 3, the recognition circuit 22 identifies the dimensions, surface condition, shape, etc. of the solid 3, and also measures the solid 3 based on the setting conditions of the setting unit 21. The coordinate position of each point and the dimensions, surface condition, shape, etc. of the identified solid 3 are displayed on the display means 23.

Therefore, according to the embodiment, the slit light irradiation portions of the solid body 3 move up and down sequentially, and the slit light irradiation portions of the solid 3 move up and down in sequence, and the slit light irradiation portions of the solid body 3
Images are taken from two directions by both imaging means 9α and 9β 7d, and a pair of imaging outputs are obtained for each slit light irradiation portion.

Furthermore, the computer 14 to which each pair of imaging outputs is input calculates each point of the irradiated area of each slit light from four simple arithmetic operations based on the position information of the slit light in each pair of imaging outputs, that is, The position of each point of 3 is calculated and measured.

In addition, before starting measurement using the gauge 11, the reference points in the X-axis direction of each of the measuring instruments 7a to 7d are measured or corrected, and the coordinates of each calculated point are transformed. The position of each point on the surface of 3 is calculated and measured using a three-dimensional coordinate system that is different for each measuring device 7a to 7d or a standard three-dimensional coordinate system that is common to all measuring devices 7a to 7d.

Since each point on the surface of the solid 3 is calculated and measured using simple arithmetic operations, the calculation and measurement can be performed in a short time using the conventional non-contact method.

In addition, in order to obtain a pair of imaging outputs by imaging the irradiated portion of each slit light from two directions, upper and lower, respectively, by a pair of imaging means 9α and 9β, for example, one imaging means 9α and 9β is provided. light projecting means and 1
Compared to a method in which one imaging output is obtained for each slit light irradiation area by using a TV camera on a stand, etc., the irradiation optical axis of the light projecting means 8 and both imaging means 9
By reducing the angles formed with each of α and 9β, solid 3
Accurate measurement can be carried out even when the surface of the solid 3 is small or when the surface of the solid 3 is uneven.

Furthermore, since the measurement is performed without contact, even if the solid 3 is made of rubber or other flexible and deformable material, it can be easily measured.

And because it uses linear slit light,
It has a low energy density and can be used as a weak light, and the three-dimensional object 3 will not be distorted by the heat of the illumination when the illumination is used.

In addition, both the imaging means 9α of each measuring device 7a to 7d,
9β may be constituted by a MOS image sensor, an image pickup tube, or the like.

Further, the number of columns and measuring instruments provided around the base 1 may be at least two; for example, the first
Diagonal struts 4a-4b and measuring device 7a in the figure
It is possible to measure even if only 7c is provided.

〔Effect of the invention〕

As described above, according to the three-dimensional measurement method of the present invention, a plurality of non-contact measurements are carried out by vertically moving the columns 6a to 6d so as to surround the three-dimensional object to be measured 3 placed on the support stand 2 on the base 1. The measuring instruments 7a to 7d are provided, and each measuring instrument 7a to 7d is moved in the vertical direction, and the light projecting means 8 of each measuring instrument 7a to 7d illuminates the solid body 3 with horizontal linear slit light. The light irradiated area is imaged by a pair of imaging means 9α and 9β located above and below the light projecting means 8 of each of the measuring instruments 7a to 7d, and in each pair of imaging outputs obtained by this imaging, Based on the position information of the slit light, the horizontal direction and the vertical direction are set as the Z-axis direction and the X-axis direction3.
The position of point G (x, y, z) of the irradiated part in dimensional coordinates is expressed as: x=(d-Kx)・{L/L+(d-e)-1}+dy -e) z=Kz・r d, e is the X of point G at each of the pair of imaging outputs
Axial distance data L is the distance Kx, Ky between the pair of imaging means in the X-axis direction
are coefficients in the X-axis direction and Y-axis direction that are set based on the lens magnification and position of the pair of imaging means. r is the scanning line number of point G in the pair of imaging outputs. Kz is the number of scanning lines. Because each position on the surface of the solid 3 was calculated and measured using the four arithmetic operations of coefficients determined by the width and lens magnification, the surface of the solid 3 was measured without moving the solid 3 during the measurement, and regardless of its size. It is possible to quickly and accurately measure each position in a short time without contact.

[Brief explanation of the drawing]

The drawings show one embodiment of the stereometer measuring method of the present invention, FIG. 1 is a perspective view of the measuring device, and FIG. 2 is a perspective view of the measuring device.
Fig. 3 is an exploded perspective view of the non-contact measuring device, Fig. 3 a and b are front views of the imaging screens of both image sensors in Fig.
The figure is a circuit block diagram, FIG. 5 is a block diagram of both image processing means in the electronic computer of FIG. 4, and FIGS.
7a to 7c are timing charts for explaining the operation of FIG. 5, and FIG. 8 is a schematic diagram for explaining the operation of the arithmetic circuit of FIG. 5. 3...Stereoscopic, 7a-7d...Non-contact measuring device, 8
...Light projecting means, 9α, 9β...imaging means.

Claims (1)

[Scope of Claims] 1. A three-dimensional object to be measured is placed on a horizontal support stand on a base, a plurality of supports are erected around the base, and each support support is provided with a horizontal line shape. A non-contact measuring instrument having a light projection means for irradiating the three-dimensional slit light onto the three-dimensional object and a pair of imaging means for imaging the irradiated part of the three-dimensional object from two directions, above and below the light projecting means, is moved up and down. At the same time, the horizontal and vertical directions can be moved in the Z-axis direction and the The position of the point G (x, y, z) of the irradiated part in the three-dimensional coordinates as the direction is x = (d'-Kx) {L/L + (d-e)-1} + d y = Ky・L/L+(d-e) z=Kz・r d and e are the X of point G at each of the pair of imaging outputs
Axial distance data L is the distance between the pair of imaging means in the X-axis direction Kx, Ky are the coefficients in the X-axis direction and Y-axis direction that are set based on the lens magnification, position, etc. of the pair of imaging means r is The scanning line number Kz of point G in a pair of image pickup outputs is obtained from four arithmetic operations of coefficients determined by the number of scanning lines, width, and lens magnification, and each position on the surface of the three-dimensional object is calculated and measured. A three-dimensional measurement method.