JP3043910B2 - A device for measuring the degree of curvature of telephone poles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the degree of curvature of a utility pole from the ground in a non-destructive manner.

[0002]

2. Description of the Related Art An electric pole that is curved due to imbalanced load is in an unstable state in terms of both material and mechanical properties, leading to a decrease in strength due to cracks and fatigue, and a sudden occurrence of wind and snow. Danger of collapse due to load. For this purpose, it is necessary to measure and manage the degree of curvature of the utility pole. Conventionally, as a method for measuring the degree of curvature of a utility pole, a method based on visual observation has been generally used.

[0003]

However, the method of measuring the degree of curvature of a utility pole by visual observation has the drawback that there is a great deal of variation among the measurers and quantitative measurement is difficult.

The present invention has been proposed to improve the above-mentioned drawbacks. The purpose of the present invention is to non-destructively measure a power pole from the ground, quantitatively grasp the degree of curvature, and diagnose the soundness of the power pole. It is an object of the present invention to provide a device that performs

[0005]

In order to achieve the above object, an apparatus for measuring the degree of curvature of a telephone pole according to the present invention comprises an image pickup device for picking up an image of a telephone pole and a video signal from the image pickup device having a predetermined resolution. And a conversion device that assigns a density value that is a numerical value according to the strength of the signal to each pixel, and a direction perpendicular to the longitudinal direction of the telephone pole with respect to the image data that is a set of one density value screen Assuming a first step of creating edge image data, which is an image in which the contour of the telephone pole is emphasized by taking a difference in density value, and a straight line extending in the longitudinal direction of the telephone pole on the edge image data. A second step of adding the density values of the pixels on the straight line, a third step of detecting a straight line having the largest added value in the second step, and a third step of the edge image data Area around the straight line detected in step A fourth step of assuming a polygonal line slope and length of different at least two linked straight going by adding the density values of the pixels applied on the polygonal line in,
Comparing a fifth step of detecting the highest sum value is greater polygonal line in stroke of said 4, the largest additional value P _br in the largest additional value P _st and the fifth stroke of the third stroke , P _br > P _st , it is determined that the utility pole is curved, and the sixth step of calculating the magnitude and the bending position of the curve based on the bending angle and the bending position of the broken line assumed in the fourth step is performed. And processing means for processing.

[0006]

In the apparatus for measuring the degree of curvature of a utility pole according to the present invention,
Take the entire image of the telephone pole, find the telephone pole outline by image processing, and find the assumed straight line and the assumed broken line that have the highest degree of overlap with the telephone pole outline with the maximum value of the sum of the density values of the coordinates passing through those lines The bending is calculated and evaluated mathematically and geometrically by comparing the degree of overlap between the assumed straight line and the assumed broken line. This makes it possible to measure the degree of curvature of the utility pole quantitatively independent of the operator, and to quickly and easily measure from the ground nondestructively.

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an apparatus for measuring the degree of curvature of a utility pole according to the present invention. An apparatus for measuring the degree of curvature of a utility pole according to the present embodiment includes an imaging device 1, a conversion device 2,
It comprises an arithmetic unit 3, a power supply 4, a signal cable 5, and a holder 6. The arithmetic unit 3 further includes a memory 7, an arithmetic unit 8, and an output unit 9, as shown in FIG. Note that the imaging device 1 and the conversion device 2 can be used separately by interposing a video recording medium such as a video floppy disk.

[0009] The video signal of the telephone pole 20 captured by the imaging device 1 is A / D converted by the converter 2, for example, 4
It is replaced with image data 10 having a resolution of 00 (horizontal) × 600 (vertical) pixels. The image data 10 is stored in the memory 7 and is used for calculation by the calculation unit 8. The operation result is
Displayed or printed by the output unit 9.

FIG. 3 is a flowchart showing a basic flow of the processing performed by the arithmetic unit 8. Step 1 is a step of converting the image data into an image that can be easily processed later. That is, edge image data is created in which the edges are emphasized so that the outline of the telephone pole in the image data can be easily detected. Steps 2 and 3 are steps for finding the contour position of the telephone pole from the edge image data. That is, assuming a starting point coordinate and a straight line having different inclinations extending in the longitudinal direction of the utility pole in step 2, the straight line having the highest matching is obtained by superposing and applying the straight line with the edge image data, and selecting one of the overlapping lines in step 3. To detect. If the utility pole is straight, this straight line represents the contour itself. If the telephone pole is curved, it represents a straight line passing through the nearest neighborhood of the contour. In other words, the true contour of the utility pole exists near this straight line. Steps 4 and 5 are steps for tracking the contour of the utility pole. That is, in step 4, a broken line having a different section length and a different slope is assumed near the straight line detected in step 3, and overlapped with the edge image data. In process 5,
By selecting one of the most overlapping broken lines, the broken line with the highest matching is detected. If the telephone pole is straight, the polygonal line selected here has a lower degree of overlap than the straight line selected in step 3. If the utility pole is curved, the degree of overlap increases, and this broken line becomes the closest approximation line imitating the curved state. Step 6 is a step of measuring the degree of curvature of the utility pole. That is, the degree of overlap between the straight line detected in step 3 and the broken line detected in step 5 is compared, and it is determined that the telephone pole is curved only when the degree of overlap between the broken lines is higher, and the bending angle of the broken line and the broken angle are determined. The magnitude and position of the curvature are obtained from the position.

Next, the flowcharts of FIGS. 4 to 8 and FIGS.
The detailed flow of the processing performed by the arithmetic unit 8 will be described with reference to the schematic diagram of FIG. 4 to 8 show one flowchart in total.
Flow lines (flow lines) are continuous at the same numbers (1 to 4) in the marks or ′ 's.

At step 1 in FIG. 4, image data 10 is input. FIG. 9 shows a schematic diagram of the image data. Although the present embodiment deals with image data composed of 400 (horizontal) × 600 (vertical) pixels, the schematic diagrams of FIGS. 9 to 11 and FIGS. 13 and 15 show simplified image sizes. I have. The density value of each pixel has a value range of 0 to 255 when quantized by 8 bits, but is represented by two values of 0 and 1 in the schematic diagram for simplification.

Steps 2 and 3 in FIG. 4 correspond to step 1 in FIG. In step 2, an image in which the image data is shifted by one pixel in the horizontal direction (hereinafter referred to as shifted image data) is created. FIG. 10 is a schematic diagram of the shifted image data corresponding to FIG. In step 3, an image (hereinafter referred to as edge image data) is created by subtracting the shifted image data from the original image data. By this process, a large value is given to the edge image data only to pixels having a sharp change in the density value in the horizontal direction, and the contour of the telephone pole is emphasized. FIG. 11 shows a schematic diagram of the edge image data with respect to FIG. 9 (results in pixels having density values other than 0 being “1”
I have to).

Steps 4 to 15 in FIG. 5 correspond to step 2 in FIG. As shown in FIG. 12, the edge image data is regarded as an XY plane, and a slope a and an X intercept b are placed thereon.
X = aY + b. When the image of the telephone pole is greatly displaced from the center of the screen, optical distortion of the lens is applied to the image, so that accurate curvature measurement cannot be performed. Therefore, the measurable range (the range of the X intercept of the assumed straight line) is set from b = b _start to b = b _end . In consideration of the case where the image of the telephone pole is tilted in the screen, the tilt is set at a predetermined interval (Δ) within a range from a = −a _max to a = + a _max.
Shake in a). In steps 4 to 6, the value b of the X intercept is set to s
In steps 7 to 9, the value of the gradient a is changed.
Further, in steps 10 to 13, a straight line X = aY + b [Y =
0-599] are calculated. step
At 15, the density value of the pixel on the coordinates (X, Y) is read, and the value is added to the variable P (a, b) and added. P (a, b) is a variable having the slope a and the X intercept b as independent parameters, and is initialized to zero by step 14. FIG. 13 is a schematic diagram showing how a straight line is applied to edge image data, and four straight lines (X = 10, X
= 6, X =-／ * Y + 9, X =-／ * Y + 1
3) is detected.

Step 16 in FIG. 5 corresponds to step 3 in FIG. In order to determine the degree of overlap between the telephone pole contour line and the assumed straight line, the calculated variables P (a, b) [a = -a _max to + a _max , b = b _start to in steps 4 to 15]
b _end ] and _{finds the} maximum value and _sets it as P _st . Further, the slope of the assumed straight line at this time is a ₀ , and the X intercept is b ₀ . Table 1 shows the variables P for the four straight lines detected in FIG.
It shows the value of (a, b). As a result, P _st =
17, a ₀ = 0 and b ₀ = 10 are substituted.

[0016]

[Table 1]

Steps 17 to 44 in FIGS. 6 and 7 correspond to step 4 in FIG. As shown in FIG. 14, the Y coordinate is divided into ten equal parts with a length of ΔY (= 60 pixels) [n = 1 to
9] and Y = 0 to ΔY × n (first straight line) and ΔY × n
It is assumed that a polygonal line consisting of 599 (second straight line) is in the vicinity of the straight line X = a ₀ Y + b ₀ detected in the above process. The first straight line is in steps 20 to 32, and the second straight line is in step
33 to 43, respectively. steps 17-19
To change the break point position n and change the length ratio of the first straight line and the second straight line.

The assumption of the first straight line is step 20 in FIG.
Step 32 is performed. First, steps 20-22
In the b ₀ to shake the value of X intercept b within a range of ± b _w to the center, in Step23～25, to shake the a slope within the range of ± a _max mainly a ₀ at a predetermined increments Δa . Further steps
26 to 29, straight line X = aY + b [Y = 0 to ΔY × n]
Calculate all coordinates that pass through. In step 31, the density value of the pixel on the coordinates (X, Y) is read, and the value is added to the variable P (a, b) and added. P (a,
b) is a variable having the slope a and the X intercept b as independent parameters, and is initialized by step 30. step32
Is a variable P (a, b) [a = −a _max to + a _max , b = b
₀ −b _{w to} b ₀ + b _w ], and finds the maximum value, and calculates P ₁ (n)
And Also, the slope of the first straight line at that time is a
₁ (n), and the X intercept is b ₁ (n).

The assumption of the second straight line is shown in step 33 in FIG.
Step 43 is performed. In step 33, b
₁ Determine the value of X intercept b based on the value of (n), and
In steps 34 to 36, the inclination a is swung at predetermined intervals Δa within a range of ± a _max around a ₀ . In steps 37 to 40, all coordinates passing through the straight line X = aY + b [Y = ΔYxn to 599] are calculated. In step 42, the coordinates (X, Y)
The density value of the upper pixel is read, and the value is added to the variable P (a) and added. P (a) is a variable having a slope a as a parameter, and is initialized to zero by step 41. In step 43, the variable P (a) [a = a ₀ −a
_max ~a locate the maximum value from among ₀ + a _max], and P ₂ (n). Also, the slope of the second straight line at that time is represented by a ₂ (n),
The X intercept is designated as b ₂ (n).

The polygonal line is represented as a connecting line between the first straight line and the second straight line. Therefore, in order to obtain the degree P _br (n) between the assumed broken line and the telephone pole contour at the break point position n, s
In step 44, P _br (n) = P ₁ (n) + P ₂ (n) is calculated.

Step 45 in FIG. 8 corresponds to step 5 in FIG. The maximum value is searched for from the variable P _br (n) [n = 1 to 9] and is set as P _br . The break point position n at that time is _defined as n _p . FIG. 15 schematically shows a state in which the outline of the telephone pole and the assumed broken line are most overlapped. (Since the image size is simplified, the Y coordinate is set to ΔY = 5 pixels in length of 5 pixels. Equally divided [n = 1 to 4]). As a result, P _br = 23 and n _p = 2 are substituted.

Steps 46 to 49 in FIG. 8 correspond to step 6 in FIG. In order to compare the degree of overlap between the case where the telephone pole contour is approximated by a straight line and the case where the line is approximated by a polygonal line,
In step46, to compare the P _st and P _br. If P _st > P _br , the process proceeds to step 47 and outputs that the utility pole is not curved. If P _st <P _br , the process proceeds to step 48, where the magnitude of the curvature is θ = │tan ⁻¹ (a ₁ (n _p )) −
tan ^-1 (a ₂ (n _p )) |, and the bending position d is ΔY from the top of the column.
Output that the point is × n _p . Here, P _st = 17
<P _br = 23, so a result as shown in Table 2 is output,
The process ends (step 49).

[0023]

[Table 2]

[0024]

As described above, according to the apparatus for measuring the degree of curvature of a utility pole according to the present invention, in order to measure the degree of curvature, only the entire image of the utility pole is taken. Measurement becomes possible. Further, since the bending of the contour of the telephone pole is calculated and evaluated mathematically and geometrically, quantitative measurement independent of the measurer can be performed. Therefore, the judgment action that has been performed visually can be performed absolutely and quantitatively by a machine. In addition, it is expected that the time for outdoor work can be reduced by separating the imaging work (outdoor) and the calculation work (indoor).

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of an apparatus for measuring the degree of curvature of a utility pole according to the present invention.

FIG. 2 is an internal configuration diagram of an arithmetic unit in the embodiment.

FIG. 3 is a flowchart showing a basic flow of a process performed by the arithmetic unit in the embodiment.

FIG. 4 is a flowchart (part 1) illustrating a detailed flow of a process performed by the arithmetic unit in the embodiment.

FIG. 5 is a flowchart (part 2) showing a detailed flow of a process performed by the arithmetic unit in the embodiment.

FIG. 6 is a flowchart (part 3) showing a detailed flow of a process performed by the arithmetic unit in the embodiment.

FIG. 7 is a flowchart (part 4) showing a detailed flow of a process performed by the arithmetic unit in the embodiment.

FIG. 8 is a flowchart (part 5) showing a detailed flow of a process performed by the arithmetic unit in the embodiment.

FIG. 9 is a schematic diagram illustrating an example of input image data input to the arithmetic device in the embodiment.

FIG. 10 is a schematic diagram showing an example of shifted image data created by the arithmetic unit in the embodiment.

FIG. 11 is a schematic diagram showing an example of edge image data created by the arithmetic device in the embodiment.

FIG. 12 is an explanatory diagram of a straight line assumed to detect a pole position from edge image data in the embodiment.

FIG. 13 is a schematic diagram showing a state where a hypothetical straight line is applied to edge image data in the embodiment.

FIG. 14 is an explanatory diagram of a polygonal line assumed for detecting a contour of a telephone pole from edge image data in the embodiment.

FIG. 15 is a schematic diagram showing a state where a hypothetical broken line is applied to edge image data in the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Image pick-up device 2 ... Conversion device 3 ... Calculation device 7 ... Memory 8 ... Calculation part 9 ... Output part 10 ... Image data 20 ... Telegraph pole

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-65605 (JP, A) JP-A-63-308679 (JP, A) JP-A-1-271885 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G01B 11/00-11/30 102 E04H 12/12 G06T 7/60 H02G 7/00

Claims (1)

(57) [Claims] An image pickup device for picking up a telephone pole, a conversion device for decomposing a video signal from the image pickup device into a predetermined resolution, and giving a density value which is a numerical value corresponding to the strength of the signal for each pixel. Edge image data which is an image in which the contour of the telephone pole is emphasized by taking a difference between the density values in the direction perpendicular to the longitudinal direction of the telephone pole with respect to the image data which is a set of the density values for one screen. A first step, a second step of assuming a straight line extending in the longitudinal direction of the telephone pole on the edge image data, and adding the density values of pixels on the straight line; A third process for detecting a straight line having a large addition value, and at least two connected straight lines having different inclinations and lengths in a neighboring area centered on the straight line detected in the third process on the edge image data. Assuming a broken line, hanging on the broken line Wherein the fourth step of gradually adding a density value of a pixel, a fifth step of detecting the highest sum value is greater polygonal line in stroke of the fourth, the largest additional value P _st in the third stage The largest added value P _br in the fifth process is compared, and only when P _br > P _st , it is determined that the utility pole is curved, and based on the bent angle and the bent position of the broken line assumed in the fourth process. And a calculating means for processing a sixth step of calculating the bending size and the bending position.