JP2014021067A - Reinforcing-bar arrangement information acquisition method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To acquire the diameter of a reinforcing-bar accurately regardless of the direction of photographing the reinforcing-bar.SOLUTION: A method includes: disposing a background bar behind a reinforcing-bar; photographing the reinforcing-bar with a camera; calculating a diametric length Wmk of the reinforcing-bar on the basis of a length per pixel of an image and the number of pixels of a photographic image in which the reinforcing-bar is projected onto the background bar; then calculating, based on the length per pixel and the like, a distance LtkR between the camera and a right edge of the reinforcing-bar being photographed, and a distance LtkL between the camera and a left edge of the reinforcing-bar being photographed; then calculating the diameter of an inscribed circle on the basis of the fact that a cross-section of the reinforcing bar constitutes the inscribed circle of a triangle with lengths of three sides of Wmk, LtkR and LtkL. Specifically, an area S of the triangle is calculated from the lengths of three sides using the Heron's formula (formula 1). Meanwhile, with rk defined as the radius of the inscribed circle, the area S of the triangle is calculated as: S=rk×(sum of lengths of three sides)/2 (formula 2). Based on the formulae 1 and 2, the radius rk is calculated from the lengths of three sides. Two times the radius is the diameter of the inscribed circle, that is, an actual diametric length Rk of the reinforcing-bar.

Description

  The present invention relates to a method of correcting a reinforcing bar diameter in an automatic measuring method of the number, diameter, and pitch of reinforcing bars.

  It is known to measure the number, diameter, and pitch of reinforcing bars by photographing the reinforcing bars of a reinforced concrete structure with a digital camera, etc., and processing the captured images with a computer (image processing) at the construction site. (See Patent Document 1). In the invention described in Patent Document 1, as shown in FIG. 14A, a background bar B is installed behind the main reinforcing bar S that is a vertical reinforcing bar, and the reinforcing bar is photographed. After that, as shown in FIG. 14B, the number of pixels Wp of the black region corresponding to the reinforcing bar is counted in the photographed image, and the diameter length Wm of the reinforcing bar is determined according to the calibration result and the distance L between the camera and the reinforcing bar. Is calculated. For details of the calculation method, refer to paragraphs 0043 and 0049 of FIG.

JP 2012-67462 A

  However, the region corresponding to the reinforcing bar on the captured image is the one in which the reinforcing bar is projected onto the background bar B in the shooting direction from the camera, and as shown in FIG. The width of the reinforcing bar located at a position diagonally from is taken as a larger image and the calculated reinforcing bar diameter Wmk is also larger than the actual reinforcing bar diameter.

  The present invention has been made in view of the above problems, and a main object thereof is to obtain the diameter of a reinforcing bar accurately regardless of the shooting direction of the reinforcing bar.

  In order to solve the above-mentioned problems, the present invention provides a reinforcing bar comprising a strip-shaped plate material having at least one surface different in color from the reinforcing bar, and a plurality of patterns provided at predetermined intervals in the longitudinal direction of the plate material. The information processing apparatus that has acquired the data of the reinforcing bar image captured by the imaging apparatus with the background of the plate member of the imaging tool as a background processes the image and acquires bar arrangement information including the length of the reinforcing bar. A method in which the information processing device specifies a one-pixel length, which is a length per pixel in the image, based on the pattern, and to one end of a reinforcing bar projected on the background A pixel value up to the other end of the reinforcing bar projected on the background as a second pixel value, a pixel length of the first pixel, A step of calculating a radial length of the reinforcing bar based on the kussell value and the second pixel value; a step of calculating the radial length of one of the reinforcing bars based on the one pixel length and the first pixel value; Calculating a first distance, which is a distance between the ends, and based on the one pixel length and the second pixel value, the imaging device and the other radial end of the reinforcing bar Performing a step of calculating a second distance, which is a distance between, and a step of calculating a diameter length of the actual reinforcing bar based on the diameter length of the reinforcing bar, the first distance, and the second distance. Features.

  According to this method, the diameter of the captured image of the reinforcing bar projected on the background of the reinforcing bar imaging tool is not directly used as the actual length of the reinforcing bar. The actual length of the reinforcing bar is calculated by considering the distance between both ends of the direction. According to this, since the angle of photographing is reflected in the distance between the photographing device and both ends of the reinforcing bar of the photographed image, even if the reinforcing bar in the oblique direction is photographed instead of the front of the photographing device. The actual length of the reinforcing bar can be calculated without error. That is, the diameter of the reinforcing bar can be accurately obtained regardless of the direction in which the reinforcing bar is imaged from the imaging device.

  In the bar arrangement information acquisition method of the present invention, in the step of calculating the actual length of the reinforcing bar, the length of the reinforcing bar projected on the background, the first distance, and the second distance are defined as three sides. Alternatively, the diameter of the inscribed circle of the triangle may be calculated as the actual length of the reinforcing bar.

  According to this method, the diameter of the rebar, the distance between the photographing device and the one end of the photographing rebar, the circle inscribed in the triangle having the three sides of the distance between the photographing device and the other end of the photographing rebar, Assuming a cross-sectional shape, the diameter of the circle is the actual length of the reinforcing bar. According to this, the diameter of the reinforcing bar can be obtained with high accuracy by simple calculation.

  In addition, the problems disclosed by the present application and the solutions thereof will be clarified by the description of the mode for carrying out the invention and the drawings.

  According to the present invention, the diameter of the reinforcing bar can be obtained with high accuracy regardless of the shooting direction of the reinforcing bar.

It is a figure which shows the structure of the bar arrangement information acquisition system. 2 is a diagram showing a hardware configuration of a mobile terminal 4. FIG. 2 is a diagram illustrating a hardware configuration of a management server 5. FIG. It is a figure which shows the structure of the data memorize | stored in the bar arrangement information acquisition system 1, (a) shows the structure of the data memorize | stored in the memory | storage part 45 of the portable terminal 4, (b) is the memory | storage part of the management server 5 The structure of data stored in 55 is shown. It is a figure which defines the state of a deformed reinforcing bar, (a) shows the state of rib position 0 °, (b) shows the state of rib position 90 °, (c) shows the state of rib position 60 °. It is a figure which shows the structural example of the reinforcement standard information 452 of the portable terminal. It is a flowchart which shows the imaging | photography method of a rebar image. 6 is a flowchart illustrating an example of image processing by the portable terminal 4; It is a flowchart which shows the reinforcement diameter estimation process by the portable terminal. It is a figure regarding the background bar B, (a) shows the shape of the background bar B, (b) shows the example of a marker. It is a figure which shows the example of an actual deformed reinforcing bar. It is a figure for demonstrating the acquisition process of the main reinforcement arrangement | positioning information, (a) shows the image of the state by which the background bar B was inserted horizontally in the vertical main reinforcement S, (b) demonstrates the measurement principle. Figure for shows. It is a figure for demonstrating the method of correct | amending the reinforcing bar diameter Wmk. It is a figure for demonstrating the acquisition processing of the conventional reinforcement arrangement | positioning information, (a) shows the image which inserted the background bar B horizontally in the main reinforcement S standing upright, (b) is a measurement principle. The figure for demonstrating is shown.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. In the bar arrangement information acquisition system according to the embodiment of the present invention, at a construction site, a background bar with markers (patterns) at both ends is arranged behind the deformed reinforcing bars, and the markers at both ends and a space between them are used using a digital camera. Take a picture of the deformed reinforcing bar, use the mobile terminal (rebar arrangement information acquisition device) to obtain the reinforcing bar information such as the number, diameter length, and pitch (interval) of the deformed reinforcing bar from the photographed image, and type of each reinforcing bar from the distribution of diameter length (Standard, nominal diameter and nominal diameter). In particular, the diameter length of the reinforcing bar projected on the background bar as a captured image is corrected using the distance between the camera and the reinforcing bar. In the present embodiment, it is assumed that the main bars are arranged in the vertical direction.

  According to this, the diameter of the reinforcing bar close to the true value can be obtained by performing correction in accordance with the position of the reinforcing bar on the background bar, that is, the shooting angle of the reinforcing bar viewed from the digital camera.

≪System configuration and overview≫
FIG. 1 is a diagram illustrating a configuration of a bar arrangement information acquisition system 1. The bar arrangement information acquisition system 1 includes a digital camera 3 and a portable terminal 4 at a construction site, and a management server 5 at an office. Data can be transmitted / received between the digital camera 3 and the portable terminal 4 through a USB (Universal Serial Bus) cable or the like. Data can be transmitted and received between the portable terminal 4 and the management server 5 by wireless communication or the like.

  The digital camera 3 is used to take an image of the imaging target part 2 such as a pillar, a beam, a floor, or a wall including a reinforcing bar, and has a pixel count of, for example, 4 million pixels or more and can turn off the autofocus function. It is done. The portable terminal 4 is a portable information processing device, takes in a digital image taken from the digital camera 3 to generate reinforcement information, receives design drawing information from the management server 5, and arranges information and design drawing information. Are compared and checked to determine whether the finished shape is valid. The mobile terminal 4 may be replaced by a PC (Personal Computer) or a server. The management server 5 includes a storage unit 55 that stores design drawing information and construction photo information, and transmits and receives such information to and from the mobile terminal 4.

<< Device configuration >>
FIG. 2 is a diagram illustrating a hardware configuration of the mobile terminal 4. The portable terminal 4 includes a communication unit 41, a display unit 42, an input unit 43, a processing unit 44, and a storage unit 45. The communication unit 41 is a part that performs data communication with the digital camera 3 and the management server 5, and is realized by, for example, a USB port or a NIC (Network Interface Card). The display unit 42 is a part that displays data according to an instruction from the processing unit 44, and is realized by, for example, a liquid crystal display (LCD). The input unit 43 is a part where an operator inputs data (for example, data such as reinforcing bar standard information), and is realized by, for example, a keyboard or a mouse. The processing unit 44 delivers data between each unit and controls the entire mobile terminal 4 and is realized by a CPU (Central Processing Unit) executing a program stored in a predetermined memory. The The storage unit 45 stores data from the processing unit 44 and reads the stored data, and is realized by, for example, a nonvolatile storage device such as a flash memory or a hard disk device.

  FIG. 3 is a diagram illustrating a hardware configuration of the management server 5. The management server 5 includes a communication unit 51, a display unit 52, an input unit 53, a processing unit 54, and a storage unit 55. The communication unit 51 is a part that performs data communication with the portable terminal 4 via a wireless network, and is realized by, for example, a NIC or the like. The display unit 52 is a part that displays data in accordance with an instruction from the processing unit 54, and is realized by, for example, a liquid crystal display. The input unit 53 is a part where an operator inputs data (for example, data such as design drawing information), and is realized by, for example, a keyboard or a mouse. The processing unit 54 exchanges data between the units and controls the entire management server 5 and is realized by the CPU executing a program stored in a predetermined memory. The storage unit 55 stores data from the processing unit 54 and reads the stored data, and is realized by, for example, a nonvolatile storage device such as a flash memory or a hard disk device.

<< Data structure >>
FIG. 4 is a diagram illustrating a configuration of data stored in the bar arrangement information acquisition system 1. FIG. 4A shows a configuration of data stored in the storage unit 45 of the mobile terminal 4. The storage unit 45 stores an image processing program 451 and reinforcing bar standard information 452. The image processing program 451 is a program that acquires reinforcement information from image data captured by the digital camera 3 and performs a process of determining compatibility with the design drawing information. The processing unit 44 according to the necessity of the process. Is read from the storage unit 45 according to the instruction. Reinforcing bar standard information (reinforcing bar type information) 452 is table information used for obtaining a reinforcing bar standard (type) from the distribution of diameters. Details thereof will be described separately.

  FIG. 4B shows a configuration of data stored in the storage unit 55 of the management server 5. The storage unit 55 stores design drawing information 551 and construction photograph information 552 in advance. The design drawing information 551 is drawing information related to the design of a building such as a reinforcing bar (including the diameter of the deformed reinforcing bar), registered in the storage unit 55 by the administrator, and from the management server 5 to the portable terminal 4 as necessary. Sent to. The construction photo information 552 is photo information of a building at an actual construction site. Photo information taken by the digital camera 3 is transmitted to the management server 5 via the mobile terminal 4 and stored in the storage unit 55.

  FIG. 5 is a diagram for defining the state of the deformed reinforcing bar. The deformed reinforcing bar is one of building structural materials, and is a bar-shaped steel material in which an iron bar is rolled to provide unevenness on the surface. As the unevenness, as shown in FIG. 5, nodes (ribs) and ribs are provided. When viewed (taken) from a direction perpendicular to the axis of the reinforcing bar, the diameter of the deformed reinforcing bar varies depending on the position (angle) of the rib. Hereinafter, the three states will be described with the rib facing the front as a rib position of 0 °.

  FIG. 5A shows a state where the rib position is 0 °. Since the rib in this state is located on the front surface, the radial length is not affected. The right and left nodes as viewed in the drawing are alternately provided along the axial direction. Accordingly, as the diameter length of the deformed reinforcing bar, a diameter length d0 not including a node and a diameter length d1 including one node are extracted.

  FIG. 5B shows a state where the rib position is 90 °. Since the ribs in this state are located at both ends and the nodes are included in the ribs, the diameter length d2 including the ribs at both ends is extracted as the diameter length of the deformed reinforcing bar.

  FIG. 5C shows a state where the rib position is 60 °. The rib in this state affects the diameter length depending on the height of the protrusion. You can see the right-hand section but not the left-hand section when looking at the drawing. Therefore, as the diameter length of the deformed reinforcing bar, a diameter length d3 not including a node and a diameter length d4 including one node are extracted. In addition, FIG. 11 is a figure which shows the example of an actual deformed reinforcing bar.

  FIG. 6 is a diagram illustrating a configuration example of the reinforcing bar standard information 452 of the mobile terminal 4. The reinforcing bar standard information 452 is table information for estimating the rib position from the distribution of the diameter length in the photographed reinforcing bar image, and further specifying the standard (type) of the corresponding reinforcing bar. The nominal diameter 4521, the nominal diameter 4522, and the rib It is composed of records including a position 4523. A nominal diameter 4521 indicates the nominal diameter of the deformed reinforcing bar. The nominal diameter 4522 indicates a diameter (diameter length) generally referred to for a deformed reinforcing bar having a nominal diameter 4521. The rib position 4523 indicates the position (angle) of the rib when the front face of the rib is 0 °, and the rib position 4523 is 0 to 60 °, 60 to 75 °, and 75 to 90 °. The lower limit value and the upper limit value of the diameter length are shown for each of the two cases. Since the appearance of the diameter varies depending on the shape and size of the nodes and ribs, the range of the rib position 4523 may be divided into two, or may be divided into four or more.

  In the estimation of the diameter of the reinforcing bar, first, one of the three rib positions 4523 is estimated from the distribution of the lengths, and the median of the lengths is compared with the range of the lower limit value and the upper limit value. Reinforcing bar standards with diameter 4521 and nominal diameter 4522 are specified. Details will be described later.

≪System processing≫
FIG. 7 is a flowchart illustrating a method for capturing a reinforcing bar image. In the construction site, a photographer photographs a reinforcing bar using the background bar and the digital camera 3, transfers the photographed image to the portable terminal 4, and acquires reinforcement information from the photographed image using the portable terminal 4. The procedure is shown.

  First, the photographer determines the digital camera 3 (S701). At that time, it is confirmed whether or not the setting of 4 million pixels or more is possible and the autofocus function is cut off (S702). If the condition is not met (NO in S702), the digital camera 3 is selected again. Correct (S701). If the condition is met (YES in S702), the determined autofocus function of the digital camera 3 is turned off so that the focus is achieved at an appropriate distance (for example, 2 m) between the imaging target region 2 and the digital camera 3. (S703). Thereafter, the focal length is constant. Then, the calibration board is photographed and camera parameters are acquired (S704). This is called camera calibration, and detects distortion or the like of the digital camera 3 by photographing a board which is paper on which a lattice pattern or equally spaced dots are printed.

  Next, the photographer determines an imaging target region 2 including a reinforcing bar (S705), and inserts a background bar behind the reinforcing bar (S706). In order to fix the background bar, it is conceivable to use a magnet or the like when only the main bar is present. On the other hand, when both the main bar and the reinforcing bar are present, it may be leaned between the intricate reinforcing bars.

  FIG. 10A is a diagram illustrating the shape of the background bar B. FIG. The background bar B includes a plate material BA and markers MK1 and MK2. The plate material BA is a strip-shaped plate material used as a background when photographing a reinforcing bar, and a color (for example, white) different from that of the reinforcing bar is attached to at least one surface, and a reflective material is further attached. The reflective material is a material coated with a fluorescent paint or the like. According to this, when the reinforcing bar is flash-photographed, the shadow of the reinforcing bar is not reflected, and the image quality of the captured image is improved. Note that the fluorescent paint may be directly applied to the plate material BA.

Width _{T 1} of the plate BA, the pitch in the section deformed bars (e.g., 20 mm) from the large and spacing of reinforcement (e.g., 100 mm) smaller than, for example, is formed on 50 mm. On the other hand, the marker MK1 and MK2 is subjected to both ends of the plate BA, the width _{T 2} are, spacing reinforcement (e.g., 100 mm) smaller than, for example, is formed on 70mm or less.

According to this, the width T ₁ of the plate BA is larger than the pitch of the knots, regardless of the position of the background bars B, can be photographed in a state in which any of the knots is always present in front of the background bars B. Therefore, the maximum diameter length of the reinforcing bar can be measured while grasping the distribution of fushi. Then, since the size of the width T ₁ is limited, thereby shortening the calculation time. Further, since the width T ₂ of the width T ₁ and the marker MK1, MK2 plate member BA is smaller than the pitch of the reinforcement, without interfering with the reinforcement, readily background bar B can be inserted into the reinforcing bars.

  A marker is a characteristic shape that does not exist in nature, and its size (dimension) is known in advance, and it is per pixel from the size of the marker and the number of pixels in the marker in the captured image. , While recognizing the reinforcing bar between them by scanning between the two markers MK1 and MK2, and, further, between the imaging target region 2 and the digital camera 3 Used to estimate the distance between.

  FIG. 10B is a diagram illustrating an example of a marker. Cross markers and circular markers are shown. Since markers MK1 and MK2 are assigned to the background bar B and the background bar B is placed behind the reinforcing bar, the marker and the reinforcing bar at the same distance from the digital camera 3 can be photographed. Since the length per pixel is equal between the steel bar and the reinforcing bar, the diameter length and pitch can be obtained with high accuracy.

  Then, the object is photographed by the digital camera 3 from a position separated by an appropriate distance (for example, 2 m) (S707), the photographed image is transferred to the portable terminal 4, and image processing is executed (S708). The vertical angle in the shooting direction of the digital camera 3 is about 0 °, and the horizontal angle is arbitrary. Details of the image processing by the portable terminal 4 will be described later. After the image processing, the calculation result is displayed on the display unit 42 of the portable terminal 4 (S709). Then, if the calculation result is the reinforcing bar diameter and pitch of the design drawing information (YES in S710), it is determined that the bar arrangement state is normal, and the photographing operation is terminated. On the other hand, if the calculation result is not the reinforcing bar diameter and pitch of the design drawing information (NO in S710), the photographer instructs the worker on the site to correct the bar arrangement (S711), and after the correction is performed, the photograph is taken. The target region 2 is determined again (S705), and imaging work is performed.

  FIG. 8 is a flowchart illustrating an example of image processing by the mobile terminal 4. This process is performed when the portable terminal 4 acquires image data from the digital camera 3 and stores it in a built-in image memory. In this embodiment, processing when the imaging target region 2 is only the main muscle will be described.

  First, the portable terminal 4 calls an image processing program (S801). Specifically, the processing unit 54 reads the image processing program 451 from the storage unit 55, loads it into the main storage device (main memory), and positions the program counter (control pointer) at the start address of the image processing program 451. As a result, the processing unit 44 of the portable terminal 4 starts processing according to the image processing program 451. The processing flow is shown in S802 to S814.

  First, the portable terminal 4 (processing unit 44) acquires a digital image, a camera focal length FL [pixel], a reference length [mm] within the markers MK1 and MK2, and an inter-marker distance M [mm] (S802). A digital image is acquired from the digital camera 3 in the image memory via a USB cable. The camera focal length FL, the in-marker reference length, and the inter-marker distance M are acquired through the input unit 53 by a photographer's operation. The in-marker reference length is a reference length for the markers MK1 and MK2. For example, in the case of a circular marker, the length of the diameter of the circle is applied. Next, image correction and binarization are performed (S803). More specifically, the distortion or the like of the digital image is corrected using the camera parameters acquired in S704, and the corrected digital image is converted into a monochrome image with a pixel value = 0 (black) or 1 (white).

  Subsequently, the portable terminal 4 measures, from the binarized image data, an angle θ formed by the main muscle S with the vertical line and an angle θ formed by the background bar B with the horizontal line (S804). Then, the original image is rotated clockwise by an angle θ to make the background bar B parallel to the horizontal line (S805). FIG. 12A is a diagram illustrating an image in a state in which the background bar B is inserted horizontally with respect to the vertical main muscle S as a result of performing the process of making the background bar B horizontal.

Next, an image of only the background bar B is extracted (S806). An image obtained by extracting only the background bar B is shown on the upper side in FIG. Then, the maximum number of pixels in the horizontal direction along the background bar B of the markers MK1 and MK2 is counted (S807). Specifically, the maximum diameter among the circular diameters that are markers is specified, and the number of pixels included in the diameter is counted. Then, the length per pixel is obtained by dividing the reference length in the marker by the number of pixels. According to this, by using a circular marker, the maximum diameter is constant no matter which direction the marker is viewed. Therefore, even if the orientation of the marker changes, the length per pixel can be accurately specified. . Further, distances L _m1 , L _m2 and L _H from the camera are obtained (S808). As shown in FIG. 12B, the distance L _m1 is a distance between the camera and the marker MK1. The distance L _m2 is a distance between the camera and the marker MK2. The distance L _H is the distance (reference distance) between the camera and the position on the background bar B where the distance between the camera and the camera is the shortest (reference position). This is used to calculate the distance between the captured image projected on the screen. Each distance is calculated | required by the following formula | equation 1,2,3.
L _m1 = FL × (reference length of marker MK1 / number of pixels of marker MK1) Equation 1
L _m2 = FL × (reference length of marker MK2 / number of pixels of marker MK2) Equation 2
L _H = √ (L _m1 ² − (L _m1 ² −L _m2 ² + M ² ) ² / 4M ² ) Equation 3

  Furthermore, the portable terminal 4 estimates the diameter of each main muscle (S809). By estimating the diameter of the main bar, the type of the reinforcing bar is specified. Details of this processing will be separately described as subroutine processing.

  Next, the portable terminal 4 acquires the coordinates (position), posture, and design drawing information of the digital camera 3 (S810). The coordinates of the digital camera 3 are acquired as position information given to the captured image by connecting a GPS (Global Positioning System) device, for example. The attitude of the digital camera 3 is acquired by a function (function of the digital camera 3 or connected device) that detects the camera attitude at the time of shooting. The design drawing information is acquired when the mobile terminal 4 receives the design drawing information 551 stored in the storage unit 55 of the management server 5. Then, the target part (construction part) of the photographed image is specified, and the compatibility with the corresponding design drawing information is determined (S811). For example, the compatibility between the estimated deformed reinforcing bar diameter and the deformed reinforcing bar diameter included in the design drawing information is determined.

  If the drawing is completed (YES in S812), the portable terminal 4 outputs the design drawing information and the recognition information to the display unit 42 (S813). The design drawing information is a target portion, coordinates, number, pitch, diameter length, etc. of the reinforcing bar on the drawing. The recognition information is the actual number of reinforcing bars, pitch, and diameter. If the drawing is not made (NO in S812), the arrangement abnormality abnormality information indicating the abnormality content, the design drawing information, and the recognition information are output to the display unit 42 (S814). Note that the compatibility determination result can be transmitted to another device through the communication unit 41 instead of being output to the display unit 42.

  FIG. 9 is a flowchart showing a rebar diameter estimation process by the mobile terminal 4. This is a processing of a rebar diameter estimation subroutine including main bars and reinforcement bars in the image processing program. The continuous diameter length of each reinforcing bar is extracted from the binarized image data, and the diameter length data The number of data and the mode value are obtained by removing noise, and the standard of the reinforcing bar is specified according to the value obtained by dividing the mode value by the number (index value of variation in diameter data).

  First, the mobile terminal 4 extracts a continuous diameter [mm] corresponding to the position of 1 pixel in the width direction (vertical direction) with respect to the background bar B (S901).

  Referring to FIG. 12B, first, a pixel having a pixel value of 0 (black) is searched in the longitudinal direction (horizontal direction) from a marker MK1 to MK2 at a predetermined position in the width direction of the background bar B, and the rebar diameter is determined. The number of pixels along the background bar B, Wpk (k is the number of the reinforcing bar), is searched for pixels with a pixel value of 1 (white), and the number of pixels along the background bar B between the reference position, each reinforcing bar, and the marker Pn (n is a pitch number) is obtained.

Next, the intervals _mn and the reinforcing bar diameters W _mk along the background bar B between the reinforcing bars adjacent to the reference position, the adjacent reinforcing bars, and the reinforcing bars adjacent to the marker are obtained. Then, from each interval _mn and each reinforcing _bar diameter W _mk , a pitch m _n ′ indicating the distance between the central axis of the reinforcing _bar adjacent to the reference position, the central axes of the adjacent reinforcing bars, and the central axis of the reinforcing bar adjacent to the marker. Ask for. Further, the distance from the reference position to the central axis of the reinforcing bar is obtained using the pitch m _n ′, and the distance L _tk from the camera to each reinforcing _bar is obtained from the distance and the reference distance L _H. For example, the reinforcing bar 2 in FIG. 12B is obtained by the following formulas 4, 5, 6, and 7. Note that (ΣWpk + ΣPn), which is the denominator of Equations 4 and 5, indicates the number of pixels between the markers MK1 and MK2.
m ₂ = M × P ₂ / (ΣWpk + ΣPn) (k = 1 to 4, n = 1 to 6) Expression 4
W _m2 = M × W _p2 / (ΣWpk + ΣPn) (k = 1 to 4, n = 1 to 6) Equation 5
m ₂ ′ = m ₂ + W _m2 / 2 Equation 6
L _t2 = √ (L _H ² + m ₂ ' ² ) (7)

With respect to the reinforcing bar 1, the distance m ₁ and the reinforcing bar diameter W _m1 are obtained using the equations 4 and 5 with the subscript 2 being 1, and the pitch m ₁ ′ is the distance between the central axes of the reinforcing bars 1 and 2 Therefore, instead of Expression 6, m ₁ ′ = m ₁ + (W _m1 + W _m2 ) / 2 is used, and the distance L _t1 is calculated by using L _t1 = √ {L _H ² + instead of Expression 7. (M ₁ '+ m ₂ ') ² }. The reinforcing bar 3 is obtained in the same manner as the reinforcing bar 2 by setting the subscript 2 to 3. The reinforcing bar 4 is obtained in the same manner as the reinforcing bar 1 by setting the subscript 1 to 4 and the subscript 2 to 3.

Subsequently, the distance (first distance, second distance) between the camera and both ends in the radial direction of the captured image in which each reinforcing bar is projected onto the background bar B is set as the reference distance L _H and the reference position and end. Calculated by the distance between For example, the reinforcing bar 2 is obtained by the following formulas 8 and 9.
L _t2R = √ (L _H ² + m ₂ ² ) (8)
L _t2L = √ {L _H ² + (m ₂ + W _m2 ) ² } Equation 9

With respect to the reinforcing _bar 1, L _t1R = √ {L _H ² + (m ₂ + W _m2 + m ₁ ) ² )} is used instead of Equation 8, and L _t1L = √ {L _H ² + ( m ₂ + W _m2 + m ₁ + W _m1 ) ² } is used. The reinforcing bar 3 is obtained in the same manner as the reinforcing bar 2. The reinforcing bar 4 is obtained in the same manner as the reinforcing bar 1.

FIG. 13 is a diagram for explaining a method of correcting the calculated reinforcing bar diameters Wmk. The cross section of the reinforcing _bar can be regarded as a circle inscribed in a triangle having three side lengths W _mk , L _tkR and L _tkL , respectively. Then, the area S of the triangle is calculated from the Heron formula by the following formula 10.
S = √ {s (s−W _mk ) (s−L _tkR ) (s−L _tkL )} Equation 10
_{However, s = (W mk + L} tkR + L tkL) / 2

On the other hand, assuming that the radius of the inscribed circle is rk, the area S of the triangle is calculated by the following equation 11.
S = r _k × (W _mk + L _tkR + L _tkL ) / 2 = sr _k Equation 11
_{However, s = (W mk + L} tkR + L tkL) / 2

From the equations 10 and 11, the diameter of the inscribed circle, that is, the corrected reinforcing bar diameter R _k is calculated by the following equation 12.
R _k = 2r _k = 2S / s = 2√ {s (s−W _mk ) (s−L _tkR ) (s−L _tkL )} / s
= 2√ {(s−W _mk ) (s−L _tkR ) (s−L _tkL ) / s} Expression 12
_{However, s = (W mk + L} tkR + L tkL) / 2

  Thus, the continuous diameter length [mm] corresponding to the position of 1 pixel in the width direction with respect to the background bar B is extracted.

Next, the portable terminal 4 performs the processing of S902 to S907 as data noise removal processing. First, in the width direction with respect to the background bar B, for example, a diameter length (corrected reinforcing bar diameter R _k ) corresponding to a position within a range of ± 500 pixels is extracted from the center line of the background bar B (S902). Then, the median value M of 1000 extracted diameter lengths is acquired (S903). In this case, the median value M is an average value of the 500th diameter length and the 501st diameter length. Furthermore, data corresponding to 0.8M to 1.2M is extracted from the 1000 diameter length data (S904). Then, the number N of the extracted diameter length data is acquired (S905). Further, less than N × 0.01 data is deleted (S906). According to this, since the number of data less than 1% of the number N of diameter data is excluded, extremely large or extremely small diameter data caused by a measurement error or the like can be excluded. . Thereafter, the number of data Ni and the mode value Ymax after the completion of the noise removal process are acquired (S907).

  Therefore, the value of Ymax / Ni is obtained, and the state of the reinforcing bar (rib position) is estimated according to the value. This is because deformed reinforcing bars have nodes and ribs, so the appearance of the nodes and ribs changes depending on the direction of the reinforcing bars, and the distribution of the extracted diameter data also changes. The direction of the reinforcing bar is estimated from the index value.

  First, when the value of Ymax / Ni is less than 0.35 (YES in S908), the reinforcing bar state (rib position) is 0 ° to 60 ° (S909), and the median value Mi after noise removal processing is acquired. (S910), among the rib positions 4523 in the reinforcing bar standard information 452 (see FIG. 6) in the storage unit 45, the column 0-60 is referred to (S911). When the value of Ymax / Ni is 0.35 or more and less than 0.45 (YES in S912), the reinforcing bar state (rib position) is 60 ° to 75 ° (S913), and the center after noise removal processing The value Mi is acquired (S914), and the fields 60 to 75 in the rib position 4523 in the reinforcing bar standard information 452 of the storage unit 45 are referred to (S915). When the value of Ymax / Ni is 0.45 or more (NO in S912), the reinforcing bar state (rib position) is 75 ° to 90 ° (S916), and the median value Mi after noise removal processing is acquired (S917). ), Refer to the column of 75 to 90 in the rib position 4523 in the reinforcing bar standard information 452 of the storage unit 45 (S918).

  As a result of referring to the reinforcing bar standard information 452, it is determined whether there is a reinforcing bar standard (nominal diameter 4521 and nominal diameter 4522) corresponding to the median value Mi (S919). Specifically, it is determined whether or not a combination of a lower limit value and an upper limit value of the diameter length including the median value Mi is in each column. If it exists (YES in S919), the corresponding reinforcing bar standard is acquired (S920). If it does not exist (NO in S919), the measurement has failed (S921). According to this, since the reinforcing bar standard information 452 corresponding to the rib position (orientation) of the reinforcing bar is used, the reinforcing bar standard can be acquired with high accuracy regardless of the angle taken from any angle.

  Although the embodiment of the present invention has been described above, in order to make each device of the bar arrangement information acquisition system 1 shown in FIG. 1 function, the program executed by the processing unit of each device is stored on a computer-readable recording medium. It is assumed that the bar arrangement information acquisition system 1 according to the embodiment of the present invention is realized by recording, causing the computer to read and execute the recorded program. Note that the program may be provided to the computer via a network such as the Internet, or a semiconductor chip or the like in which the program is written may be incorporated in the computer.

According to the embodiment of the present invention described above, when the background bar B is installed behind the reinforcing bar and a photograph of the reinforcing bar is taken with a digital camera or the like, the projected length of the reinforcing bar W _mk is obtained by image processing. Can be obtained easily. Then, using the distances L _tkR and L _tkL between the reinforcing bar radial length W _mk , the camera, and the background bar B projected at both ends in the radial direction of the reinforcing bar, the inscribed triangles are _defined as three sides. By obtaining the diameter Rk of the circle, the rebar diameter can be accurately determined. That is, no error occurs even if the rebar is photographed obliquely.

<< Other embodiments >>
As mentioned above, although the form for implementing this invention was demonstrated, the said embodiment is for making an understanding of this invention easy, and is not for limiting and interpreting this invention. The present invention can be changed and improved without departing from the gist thereof, and equivalents thereof are also included in the present invention. For example, the following embodiments can be considered.

(1) In the above embodiment, as shown in FIG. 12 (a), the state in which the background bar B is horizontally inserted in the vertical reinforcing bar has been described. However, the present invention is not limited to this, and the diagonal reinforcing bar and the horizontal reinforcing bar The background bar B may intersect. In this case, if the angle between the center line of the reinforcing bar and the vertical line is Φ, correction is performed by multiplying the reinforcing bar diameter R _k by cos Φ.
(2) The target reinforcing bar is not limited to the main reinforcing bar, and may be applied to other reinforcing bars such as reinforcing bars.

DESCRIPTION OF SYMBOLS 1 Bar arrangement information acquisition system 2 Imaging | photography object site | part 3 Digital camera 4 Portable terminal (information processing apparatus)
44 processing unit 45 storage unit 451 rebar standard information (rebar type information)
5 Management server B Background bar (rebar shooting tool)
BA plate material FL Focal length Lm, L _H , Lt Distance from camera MK1, MK2 Marker (pattern)
Wp pixels

Claims (2)

With the background of the surface of the plate material of a reinforcing bar photographing tool consisting of a strip-shaped plate material having a color different from the reinforcing bar and a plurality of patterns provided at predetermined intervals in the longitudinal direction of the plate material, An information processing apparatus that has acquired image data of a reinforcing bar imaged by an imaging device is a method of processing the image and acquiring arrangement information including the length of the reinforcing bar,
The information processing apparatus includes:
Identifying a one-pixel length, which is a length per pixel in the image, based on the pattern;
Obtaining a pixel value up to one end of the reinforcing bar projected onto the background as a first pixel value, and obtaining a pixel value up to the other end of the reinforcing bar projected onto the background as a second pixel value; ,
Calculating a diameter length of the reinforcing bar based on the one pixel length, the first pixel value, and the second pixel value;
Calculating a first distance, which is a distance between the imaging device and one radial end of the reinforcing bar, based on the one pixel length and the first pixel value;
Calculating a second distance, which is a distance between the imaging device and the other radial end of the reinforcing bar, based on the one pixel length and the second pixel value;
Calculating the actual length of the reinforcing bar based on the length of the reinforcing bar, the first distance and the second distance;
The arrangement information acquisition method characterized by performing this. The bar arrangement information acquisition method according to claim 1,
In the step of calculating the diameter of the actual reinforcing bar, the diameter of the reinforcing bar projected on the background, the diameter of the inscribed circle of the triangle having the first distance and the second distance as three sides, are used as the actual reinforcing bar. A bar arrangement information acquisition method characterized in that the arrangement is calculated as the diameter length of the bar.