JP4451003B2 - Dimension measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dimension measuring apparatus that measures a dimension of a measurement object from a photographed image.
[0002]
[Prior art]
For example, when measuring the size of a measurement object such as a foreign object that is not directly visible to the operator, such as a pipe, an imaging device such as a small CCD camera attached to the end of the cable is connected to the tube. Measurement of the size of a measurement object such as the foreign matter is performed based on a photographed image in a pipeline inserted into the road and imaged by the imaging device. In such a dimension measurement method based on a photographed image, for example, (1) the distance between the imaging device and the measurement object is measured based on the parallax when the measurement object is photographed from different directions, and the dimension of the measurement object is determined. Measuring method and (2) projecting a special line shadow on the measurement object and measuring the distance between the imaging device and the measurement object based on where the line shadow is located on the shooting screen A method for measuring the dimension of a measurement object is known.
[0003]
[Problems to be solved by the invention]
By the way, the above-described prior art has a problem that the configuration of the entire apparatus is complicated, and as a result, handling is complicated and the cost is increased. That is, in each of the above conventional techniques, the position of the parallax or the linear shadow is detected by performing digital image processing on the shooting screen, and the distance between the imaging device and the measurement object is calculated based on the detection result. Since the actual dimension of the measurement object projected on the photographing screen is calculated based on the calculation result, a calculation device for performing such various calculations is required.
[0004]
In addition, the configuration of the optical system, that is, the imaging device is complicated in order to photograph the measurement object from different directions or to project a special linear shadow on the measurement object. As a result, the handling is complicated and the cost is increased, and the failure rate is increased.
[0005]
The present invention has been made in view of the above-described problems, and an object thereof is to provide a dimension measuring apparatus having a relatively simple configuration.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, as a first means related to the dimension measuring apparatus, an imaging unit that captures an image of a measurement object and a predetermined amount from the imaging unit so that the image is displayed on the imaging screen of the imaging unit. A means comprising a plurality of hands projecting forward at intervals and an image display means for displaying a photographing screen is adopted.
[0007]
Further, as a second means related to the dimension measuring apparatus, a means is used in which the pointer is formed of an elastic material in the first means.
[0008]
As a third means related to the dimension measuring apparatus, a means of adding an illumination light source to the image pickup unit in the first or second means is adopted.
[0009]
As a fourth means related to the dimension measuring apparatus, in any one of the first to third means, the imaging unit includes a small CCD camera, the small CCD camera is attached to the end of the long signal cable, and the rear end. The image display means is provided for each.
[0010]
As a fifth means related to the dimension measuring device, a means is adopted in which the cross-sectional shape of the imaging unit is a cylindrical shape in the fourth means.
[0011]
As a sixth means related to the dimension measuring apparatus, a means is adopted in which the cross-sectional shape of the imaging unit is a substantially crescent shape in the fourth means.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a dimension measuring apparatus according to the present invention will be described with reference to the drawings. In the present embodiment, the present invention is applied to an in-pipe inspection of a power pipe buried in the ground.
[0013]
FIG. 1 is a system configuration diagram showing the overall configuration of the present embodiment. In this figure, reference numeral 1 denotes an image pickup unit, 2 denotes a signal cable, 3 denotes a drum, and 4 denotes a monitor (image display means). The imaging unit 1 is attached to the front end of the signal cable 2, and the monitor 4 is connected to the rear end of the signal cable 2. As shown in the figure, the imaging unit 1 is sequentially sent into the power pipe when the operator operates the signal cable 2 and photographs the state of each part in the power pipe.
[0014]
The video imaged by the imaging unit 1 is input as a video signal to the monitor 4 via the signal cable 2 and displayed on the monitor 4 as an imaging screen. In addition, the drum 3 winds up the elongate signal cable 2 according to the length of electric power piping, and is provided on the ground.
[0015]
As shown in FIG. 2, the imaging unit 1 includes a main body 1a, a small CCD camera 1b, illumination light sources 1c and 1c, a pair of pointers 1d and 1d, and the like. The main body 1a accommodates the small CCD camera 1b and the illumination light sources 1c and 1c, and the cross-sectional shape orthogonal to the axial direction of the signal cable 2 is formed in a substantially crescent shape. Moreover, the front end surface 1e of the main body 1a is orthogonal to the axial direction of the signal cable 2 similarly to the above-described cross section, and is thus formed in a substantially crescent shape. The imaging unit 1 having such a main body shape is sequentially fed into the power pipe along a gap between the cylindrical power pipe and the power cable inserted into the power pipe.
[0016]
The small CCD camera 1b is set so that the photographing direction is directed from the front end surface 1e, and supplies the photographed video in the power pipe to the monitor 4 through the signal cable 2 as a video signal. The illumination light sources 1c and 1c are set so that the illumination direction is directed from the front end surface 1e in the same manner as the small CCD camera 1b, and one pair is provided on both sides with the small CCD camera 1b as the center. By providing the illumination light sources 1c and 1c, the small CCD camera 1b can reliably capture an image in the power pipe in the dark power pipe.
[0017]
A pair of pointers 1d and 1d are provided on the distal end surface 1e on the outer side of the illumination light sources 1c and 1c at symmetrical positions about the small CCD camera 1b. The pointers 1d and 1d are formed by forming an elastic material having elasticity into a needle shape, and are implanted on the distal end surface 1e so as to protrude forward from the distal end surface 1e at a predetermined interval L. The distance L and the positions and lengths of the hands 1d and 1d on the front end surface 1e are set so that the front ends of the hands 1d and 1d are within the photographing range of the small CCD camera 1b.
[0018]
FIG. 3 is a diagram showing a detailed configuration of such pointers 1d and 1d. The pointers 1d and 1d are formed by forming a highly elastic metal such as a titanium / nickel alloy in a wire shape and winding an intermediate portion thereof in a spring shape. That is, the pointers 1d and 1d are provided with straight portions 1h and 1i at both ends of the spring portion 1g, respectively, and are formed in a linear shape (needle shape) as a whole. The distal end of the straight portion 1h is a portion that comes into contact with the measurement object as will be described later, and the straight portion 1i is a portion that is implanted in the distal end surface 1e. The straight portion 1i is planted by being press-fitted into a hole provided in the tip surface 1e. That is, the pointers 1d and 1d are configured to be detachable from the tip surface 1e. Easy to replace.
[0019]
Next, the dimension measurement of the measurement object using the dimension measuring apparatus configured as described above will be described in detail with reference to FIG.
[0020]
FIG. 4A is an imaging screen G1 showing a state in which the size of the foreign matter W in the power pipe as the measurement object is measured. In this case, the worker adjusts the feed amount (length) of the signal cable 2 to the power pipe to bring the tips of the pointers 1d and 1d close to each other until they come into contact with the foreign object W. In this state, the distance between the tips of the pointers 1d and 1d displayed on the imaging screen G1 is a specified distance L, and the width of the foreign object W is relatively compared with the distance L between the tips on the imaging screen as a reference dimension. By doing so, the width can be easily measured.
[0021]
On the other hand, FIG. 4B is an imaging screen G2 showing a measurement state of the dimension d of the step W ′ at the connecting portion of the power pipe as the measurement object. In this embodiment, the operator manually operates the signal cable 2 to send the imaging unit 1 into the power pipe. Therefore, the imaging position of the imaging unit 1 in the power pipe cannot be freely changed. The step dimension d can be easily measured by relative comparison with the distance L between the tips of the pointers 1d and 1d in G2.
[0022]
Here, since the pointers 1d and 1d have elasticity, even if the pointers 1d and 1d collide with the foreign object W or the step W ′, the tip portions of the pointers 1d and 1d can be easily separated. Return to L. Therefore, it is possible to suppress a decrease in measurement accuracy due to a change in the distance L between the tips of the hands 1d and 1d.
[0023]
As described above, according to the present embodiment, the foreign matter W and the level difference W ′ in the power pipe are only compared with the distance L between the tips of the pointers 1d and 1d in the imaging screens G1 and G2 and the foreign matter W and the level difference W ′. Can be measured with a very simple configuration. Unlike the prior art, digital image processing and complicated arithmetic processing are not required. Moreover, since the cross-sectional shape of the main body 1a is formed in a substantially crescent shape, the gap between the power pipe and the power cable can be easily passed.
[0024]
Note that the present invention is not limited to the above embodiment, and for example, the following modifications are conceivable.
(1) Instead of the embodiment described above, it is conceivable to set the cross-sectional shape of the main body 1a ′ to a cylindrical shape as shown in FIG. In the case of the imaging unit 1A, a small CCD camera 1b is arranged at the center of the circular tip surface 1g, and a plurality of (total six) illumination light sources 1c,... Has been placed.
[0025]
(2) In the above embodiment, a pair of hands 1d and 1d are provided on the left and right sides of the small CCD camera 1b, but a pair of hands may be provided on the top and bottom instead of the left and right. Further, a total of two pairs of hands 1d and 1d may be provided on the top and bottom in addition to the left and right.
[0026]
(3) Further, in the above embodiment, the present invention is applied to the in-pipe inspection of electric power piping. However, the present invention is not applicable only to such inspection of electric power piping. It is possible to apply to the dimension measurement of various measuring objects.
[0027]
【The invention's effect】
As described above, according to the present invention, the imaging unit that captures the measurement object, and a plurality of pointers that protrude forward from the imaging unit at a predetermined interval so as to be displayed in the imaging screen of the imaging unit. Since the image display means for displaying the photographing screen is provided, the dimension of the measuring object can be measured very simply only by the relative comparison between the distance between the tip of the pointer in the imaging screen and the measuring object.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram showing an overall configuration of an embodiment of the present invention.
FIG. 2 is a perspective view illustrating a configuration of an imaging unit according to an embodiment of the present invention.
FIG. 3 is a perspective view showing a detailed configuration of a pointer in one embodiment of the present invention.
4A and 4B are a plan view showing an imaging screen related to a foreign substance in a pipe line and a plan view showing an imaging screen of a pipe level difference in one embodiment of the present invention.
FIG. 5 is a perspective view illustrating a modified example of the imaging unit according to the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Image pick-up part, 1a ... Main body, 1b ... Small CCD camera, 1c ... Light source for illumination, 1d ... Pointer, 2 ... Signal cable, 3 ... Drum, 4 ... Monitor (image display means)

Claims (6)

An imaging unit (1) for imaging a measurement object;
A plurality of hands (1d) projecting forward from the imaging unit (1) at a predetermined interval so as to be projected on the shooting screen of the imaging unit (1);
Image display means (4) for displaying the photographing screen;
A dimension measuring device comprising: 2. The dimension measuring device according to claim 1, wherein the pointer (1d) is made of an elastic material. The dimension measuring device according to claim 1 or 2, characterized in that an illumination light source (1c) is added to the imaging unit (1). The imaging unit (1) includes a small CCD camera (1a), the small CCD camera (1a) is provided at the front end of the long signal cable (2), and the image display means (4) is provided at the rear end. The dimension measuring device according to any one of claims 1 to 3. The dimension measuring device according to claim 4, wherein the cross-sectional shape of the imaging unit is cylindrical. The dimension measuring device according to claim 4, wherein the cross-sectional shape of the imaging unit (1) is substantially crescent shaped.

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