JPH0298619A - Three-dimensional length measuring equipment - Google Patents

Abstract

PURPOSE:To measure a distance to an object to be photographed by using one set of television camera by deriving a distance between an image pickup means and the object to be photographed, based on the adjustment quantity of a focus in the image pickup means and an image which is brought to image pickup. CONSTITUTION:From a projector 23, a laser light is projected to an object to be photographed 2 through a slit 24, and a band-like image 26 is projected to the object to be photographed 2. A reflected light from the object to be photographed 2 allows only a light beam of prescribed wavelength to transmit through a filter 5 of an optical system 6, and the band-like image 26 is brought to image pickup to an image pickup body 8 being a CCD image sensor. this image is inputted as picture data by an image inputted part 19, and a distance (b) between a lens corresponding to width (x) of the band-like image 26 and the object to be photographed is stored in a line width focus data storage part 18. When width of the band is the narrowest (x), a CPU 21 decides that the focus to the image 26 is adjusted, executes an operation from the distance (b) corresponding to the width (x) of the narrowest band and a known focal distance (f), and derives a distance between an industrial television camera 1 and the object to be photographed 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a three-dimensional length measuring device that measures the distance to a subject using an industrial television camera.

[Conventional technology]

Conventionally, when measuring the distance to a subject using industrial television cameras, two industrial television cameras fixed at a fixed distance capture the position of the subject, that is, the survey point, and each camera and survey point are He used the trigonometry method to find the relative angles of .

That is, as shown in FIG. 4, if the distance between two industrial television cameras 101 and 102 is assumed to be 0, and the relative angles between each television camera and the survey point X are α and β, then each television camera 101 and 102 and survey point xIS
! The respective distances L(x and ri) of i can be found from the following equation (1).

However, A=sin (180-a-β) [The problem to be solved by the invention ff1] However, the above conventional triangulation method requires two industrial television cameras, which is expensive. There was a drawback. Additionally, if there is an error in the distance between the two television cameras, it will have a significant impact on survey accuracy, so accurate alignment of the two television cameras is required.
11 rough calibration work had to be carried out as needed.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a three-dimensional length measuring device that can measure the distance to a subject using one television camera.

(Means for Solving the FJ Problem) The present invention includes a light projection means for projecting an image of light of a predetermined wavelength onto a subject, and a light projecting means for projecting an image of light of a predetermined wavelength onto a subject, and an image of light of the predetermined wavelength by passing reflected light from the subject through a filter. an imaging means for taking an image;
an adjusting means for adjusting the bin in the imaging means;
The present invention is characterized by comprising means for determining the distance between the imaging means and the subject based on the amount of focus adjustment by the adjustment means and the captured image.

[Effect]

According to the present invention, the distance between the imaging device and the subject is determined based on the amount of focus adjustment in the imaging device and the captured image. Therefore, the distance to the subject is measured using one imaging device.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram showing an embodiment of a three-dimensional length measuring device according to the present invention, and shows a state in which the distance between an industrial television camera 1 and a subject 2 is measured. In the figure, an industrial television camera 1 has a first lens 3 and a second lens 4.
and a cylinder 7 incorporating an optical system 6 consisting of a filter 5 that transmits only light of a predetermined wavelength, and a housing 9 housing an image pickup body 8 that is, for example, a COD image sensor. ? ! It is constructed by inserting a snake 11i10 that blocks light into i. The light incident on the optical system 6 reaches the image pickup body 8 via the filter 5, the first lens 3d3, and the second lens 4, and the vi image body 8 captures an image.

Further, a rack gear 11 is fixed to the seventh side portion, and this rack gear 11 meshes with a pinion gear 13 attached to one end of the rotating shaft of the electric motor 12. Therefore, as the electric motor 12 rotates, the cylinder 7 moves up and down, thereby changing the distance between the optical system 6 and the imaging body 8 and adjusting the focus. Furthermore, a potentiometer 14 is connected to the other end of the rotating shaft of the electric motor, and the rotating position of the We motor 12 is detected by this potentiometer 14.

Next, in the image processing circuit 15, a lens focus position drive section 16 rotates the electric motor 12.

Further, the lens focus position reading section 17 inputs a signal indicating the rotational position of the electric motor 12 from the potentiometer 14, and based on this rotational position, the position of the lens of the optical system 6, that is, the lens and the imaging pot body 8. The line width focus data storage unit 18 detects the distance between lines and uses this distance as focus data.
is being transmitted to. Furthermore, the image capturing unit 19
Image data representing an image is input from the image storage section 20, and this image data is transmitted to the image storage section 20. On the other hand, the central processing unit (CPU)
21 reads the nIIJ control program from the read-only memory 22, and controls the image processing circuit 15 based on this control program.

Further, the projector 23 projects, for example, a helium neon laser beam onto the subject 2 through a slit 24, so that a band-shaped image 26 is projected onto the subject 2 by the light.

Now, the reflected light from the subject 2 passes through the filter 5 of the optical system 6, so that only light of a predetermined wavelength, that is, helium neon laser light is transmitted. This transmitted light is projected onto the imaging body 8 via the first lens 3 and the second lens 4,
As a result, the band-shaped image 26 is imaged by the imaging body 8.

Here, as shown in FIG. 2, the combined focus of the first lens 3 and the second lens 4 is m, and the distance between the virtual lens 31 having the combined focus m and the imaging body 8 is bl, and in this case, Suppose that the band-shaped image 26 is out of focus and becomes a blurred Il image. In this case, since the captured band-shaped image 26 is blurred, the width of the band is x 1 as shown in the image formula of FIG.
It is getting wider. Note that the circle indicated by the broken line in the image of FIG. 3(a) corresponds to the hole 27 of the subject 2, and it is assumed that there is no reflected light from this hole.

The image @A is captured as image data by the image capturing section 19 and stored in the image storage section 20.

Then, the CPU 21 executes the image m stored in the image storage unit 20.
Determine the width x 1 of the strip @26 in A, and calculate this width x1
is stored in the line width focus data storage section 18 as data. At this time, the lens focus position reading unit 17 detects the distance b1 between the virtual lens 31 and the imaging body 8 shown in FIG. 2 based on the signal from the potentiometer 14, and stores line width focus data using this distance b1 as data. 18.

This distance 11b1 is stored in the line width focus data storage section 18 in correspondence with the width×1.

Next, the CPU 21 gives a drive command to the lens focus position drive section 16. In response to this drive command, the lens focus position drive unit 16 rotates the electric motor 12 by a predetermined rotation angle. With this,! tli7 moves downward, and the distance between the virtual lens 31 and the imaging body 8 shown in FIG. 2 becomes longer and becomes b. At this time, if the band-shaped image 26 is taken in focus, the width of the band becomes as narrow as X on the imaging body 8, as shown in image 8 of FIG. 3(b).

This image B is captured by the image capturing section 19 and stored in the image storage section 20. Then, the CPtJ 21 determines the width X of the band-shaped image 26 in the image B stored in the image storage unit 20, and converts this width X into the line width focus data storage unit 18.
to be memorized. Further, the lens focus position @ reading unit 17 detects the distance 1 m 1 lb between the virtual lens 31 and the image pickup body 8 shown in FIG. and is stored in the line width focus data storage section 18.

Furthermore, a drive command is given to the lens focus position drive section 16 from the CPtJ21, and in response, the lens focus position drive section 16 rotates the electric motor 12 by a predetermined rotation angle. As a result, the cylinder 7 moves downward, and the distance between the virtual lens 31 and the imaging body 8 shown in FIG. 2 further increases to b2. At this time, the band-shaped @26 is out of focus and becomes a blurred M image, and the width of the band becomes as wide as X2 on the imaging body 8, as shown in image C in FIG.

This image @C is captured by the image capturing section 19 and stored in the image storage section 20. Then, the CPU 21 determines the width x2 of the band-shaped image 26 in the image C stored in the image storage unit 20, and converts this width
Store in 8. Further, the lens focus position If recording unit 17 detects the distance wIb2 between the virtual lens 31 and the image pickup body 8 shown in FIG. 2 based on the signal from the potentiometer 14, and calculates this distance b2 corresponding to the width X2. It is stored in the line width focus data storage section 18.

In this way, the distance between the virtual lens 31 and the imaging body 8 shown in FIG. To detect. After this, the CPLI 21 selects the widths X1, X, and X2 of each band already stored in the line width focus data storage unit 18.
Select the one with the narrowest width. Here, the width XS of the narrowest band is selected. Then, the CPU 21 reads the distance corresponding to the width X of this band from the line width focus data storage section 18.

Now, assuming that the band-shaped image 26 is in focus when the width of the band is the narrowest, X, the distance between the virtual lens 31 and the imaging body 8 shown in FIG.
1 focal length f, and the composite lens 31 and band-shaped image 26
The following equation (2) holds true based on the distance a between.

Therefore, the distance a is expressed by the following equation (3).

Therefore, the CPL 121 substitutes the distance corresponding to the width X of the narrowest band and the known focal length f into the above equation (3), and calculates the distance a as the distance between the industrial television camera 1 and the subject 2.

As described above, in this embodiment, helium neon laser light is projected onto the subject 2 from the projector 23 through the slit 24,
A strip-shaped image 26 projected onto the subject 25 is captured by the industrial television camera 1, and the distance between the television camera 1 and the subject 2 is determined based on the strip-shaped image 26 captured by the television camera 1 and the amount of focus adjustment. I'm trying to find out. Therefore, the distance to the object can be measured using one industrial television camera.

In addition, in the 1/1 example, the distances between the lens and the imaging object are Xl, You can also calculate the distance a between the TV camera and the subject based on the distance corresponding to the width of the narrowest band and the known focal length. In this case, the distance a is
Since the distance 11a is changed to a smaller value, the degree of detection 'I#' of the distance 11a is improved.

Further, as the light image projected onto the subject, not only a band-shaped image but also one of various patterned images can be applied. For example, a circular light image may be projected onto the subject. In this case, focus is achieved when the diameter of the circular image formed by the television camera is the smallest.

【Effect of the invention〕

As explained above, according to the present invention, the focus adjustment in the image conveying means is improved! Based on the quantity and the threatened statue, said I
The distance between the image means and the subject is determined. For this reason,
11 distances to the subject using one TV camera!
It is possible to provide a three-dimensional length measuring device that can be used to measure distances.

[Brief Description of the Drawings] Fig. 1 is a schematic configuration diagram showing an embodiment of the three-dimensional length measuring device according to the present invention, and Fig. 2 is for explaining the principle of surveying in the embodiment shown in Fig. 1. Figure 3 was used in Figure 1.
FIG.
The figure is a diagram used to explain a conventional triangulation method. 1...Industrial television camera, 2...Subject, 3...
- First lens, 4... Second lens, 5... Filter, 6... Optical system, 7... Tube, 8... Imaging body,
9... Housing, 10... Bellows, 11... Rack gear, 12... Electric motor, 13... Pinion gear, 1
4... Potentiometer, 15... Image processing circuit, 16... Lens focus position drive section, 17... Lens focus position reading section, 18... ljJ width focus data storage section, 19... Image capture unit, 20... Image storage unit, 21... Central processing unit, 22... Read only memory, 23... Floodlight, 24... Slit,
26... Band-shaped statue, 27... Hole. 31...Synthetic lens.

Claims (1)

[Scope of Claims] Light projecting means for projecting an image of light of a predetermined wavelength onto a subject; imaging means for capturing an image of light of the predetermined wavelength by passing reflected light from the subject through a filter; A three-dimensional image capturing apparatus comprising: an adjustment means for adjusting the focus of the means; and means for determining the distance between the imaging means and the subject based on the amount of adjustment of the focus by the adjustment means and the captured image. Length measuring device.