JP2004361151A - Support curve measuring method and support curve measuring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a support pole curve measuring method and a support pole curve measuring system capable of computing an approximate curve expression indicating a quantitative contour curve, easily and strictly analyzing displacements of a support such as a reinforced concrete pole, and diagnosing the durability and state of load of the support on the basis of the results of analysis. <P>SOLUTION: Image data on the reinforced concrete pole including characteristic points are those in a camera coordinate system. Here, curve coordinates are computed by converting from the camera coordinate system into a world coordinate system. Through the use of the curve coordinates, the approximate curve expression of the reinforced concrete pole in the world coordinate system is determined as a support pole curve in the support pole curve measuring method and the support pole curve measuring system. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００３３】
ここにρ＝θ−γであり、デジタルカメラを通る水平線ＯＲと直線ＯＰとがなす角度である。
続いて上記の連立方程式を解く導出過程について説明する。上記連立方程式からＰＡとＡＢとを消去すると次式のようになる。
【００３４】
【数２】

【００３５】
加法定理により変換すると次式のようになる。
【００３６】
【数３】

【００３７】
ここで次式で示すように変数の変換を行う。
【００３８】
【数４】

【００３９】
この変数を用いると次式で示すようになる。
【００４０】
【数５】

【００４１】
まとめると次式で示すようになる。
【００４２】
【数６】

【００４３】
ここにｐは実数であり、（ｐ^２＋１）は０でないため消去できる。まとめると次式で示すようになる。
【００４４】
【数７】

【００４５】
さらにθ＝γ−ρの関係と先の数４による変数の関係とから次式のように変換される。
【００４６】
【数８】

【００４７】
このようにして（１）撮影角度θが算出される。
続いて（２）撮影距離ＯＲについて算出する。ＰＡとＲＰとの比を取ると次式のようになる。
【００４８】
【数９】

【００４９】
これにより次式の関係を満たす。
【００５０】
【数１０】

【００５１】
このようにして（２）撮影距離ＯＲが算出される。
続いて（３）カメラ高さＲＢについて算出される。カメラ高さＲＢは次式を満たす。
【００５２】
【数１１】

【００５３】
ここにＲＰ＝ＯＲ・ｔａｎρであり、またＰＢは標尺２０の長さであって、何れも既知の値から算出することができる。
このようにして地際Ｂに対するカメラ高さＲＢが算出される。
以上、（１）撮影角度θ、（２）撮影距離ＯＲ、および、（３）地際からデジタルカメラまでのカメラ高さＲＢ、というデジタルカメラの姿勢データを算出する。
【００５４】
さて、図６に戻る。
行程７は、標尺２０の３点の特徴点２１，２２，２３の特徴点画像座標から、無負荷状態における直線上（すなわち湾曲していない）の鉄筋コンクリート柱１０の理想軸を算出する行程（理想軸算出行程）である。
特徴点は標尺２０上に描かれた点であるから、標尺２０と輪郭線が接する直線と、特徴点重心とを結ぶ直線と、でなす角度により逆算して真の理想軸を定義する。
【００５５】
行程８は、画像データ上の鉄筋コンクリート柱１０の輪郭線上のサンプル点を入力してサンプル座標を算出する行程（サンプル点入力行程）である。
この行程では、コンピュータ（解析手段１）の図示しないディスプレイ装置に画像データを表示させ、マウス等のポインティングディバイスを用いてユーザがポインティングし、鉄筋コンクリート柱１０の輪郭線上のサンプル点を数箇所、末口点まで入力する。
【００５６】
敷設状態の鉄筋コンクリート柱１０にはさまざまな装柱機器やケーブルがあり、輪郭線が隠れてしまう部分があるため、ここでは輪郭線が明瞭に目視できる箇所をサンプル点として入力する。鉄筋コンクリート柱の頂部までまんべんなく３点以上を入力する。サンプル点は装柱機器やケーブルなどで隠れた部分を除く輪郭線が目視できる画素とする。このようなサンプル点についてサンプル座標を算出する。
【００５７】
行程９は輪郭線上のサンプル座標間を補間して補間座標を算出する行程（補間座標算出行程）である。
この行程では、入力されたサンプル点間の輪郭線を画像処理によって抽出し補間する。すなわち、数箇所入力されたサンプル点を補間し増やすことにより後述する行程１１にて得られる近似曲線式の整合性を高めることができる。
【００５８】
具体的には、図９に示すように地際から頂部に向かって各サンプル点から次のサンプル点までの矩形状の輪郭線を切り出す。ここに、輪郭線の抽出範囲はサンプル点を結ぶ直線が対称軸となるような矩形とする。切り出した各抽出範囲にて輪郭線をたどり、それらを結合することにより一本の輪郭線を生成する。
【００５９】
また、前後のサンプル点の傾きから輪郭線の方向性を加味し、輪郭線が誤った方向に大きく反れることがないよう抽出範囲の幅ａを制限することで安定した抽出を実現する。
ただし入力されたポイント間の傾き差θがほとんど変わらない部分は抽出範囲の幅は１画素すなわちほぼ直線であると思われるためそのまま直線で補間を行う。
【００６０】
続いてこのようにして切り出した各抽出範囲にて輪郭線をたどる手順について図１０を用いて説明する。
まず、切り出した矩形画像の軸が垂直になるよう回転補正し、水平方向への濃度変化を表したエッジ画像に変換する。このエッジ画像を用い、地際側つまり下部に位置するサンプル点よりその上部に位置する３画素（左上、上、右上）の中から最もエッジの強い画素を輪郭線とする。
【００６１】
さらにその画素の上部に位置する３画素の中から最もエッジの強い画素を輪郭線とする。もし、装柱機器などで輪郭線が隠れているなど、強いエッジが存在しない場合はそのまま上へ進む。これを繰り返すことにより次のサンプル点までたどりつき、１本の輪郭線が生成される。これを回転補正時の角度に基づき元にもどし各抽出範囲にて生成した輪郭線を結合することにより全体の輪郭線を生成する。
【００６２】
図６に戻るが、行程１０は、撮像手段の姿勢データを用いてカメラ座標系で表されたサンプル座標および補間座標を、行程７によって得られた理想軸を高さ方向のＹ軸とする世界座標系の曲線座標へ変換して算出する行程（曲線座標算出行程）である。
【００６３】
輪郭線に該当する画像座標をレンズの光軸位置を原点としたカメラ座標に変換する。
図１１，図１２で示すように、先に行程６で算出した撮影距離Ｌｚ、カメラ高さＣｙおよび撮影角度θ_Ａを利用してカメラ座標系の座標Ｐ（Ｐｘ，Ｐｙ）から世界座標系の座標Ｒ（Ｒｘ，Ｒｙ）へ変換する。
まず、カメラ座標系のＹ軸座標Ｐ（０，Ｐｙ）とレンズとを結ぶ直線と、光軸と、がなす角度θｙを算出する。
【００６４】
【数１２】

【００６５】
このθｙより実座標Ｒｙが算出される。
【００６６】
【数１３】

【００６７】
レンズと実座標Ｒ（０，Ｒｙ）との距離Ｃｔを算出する。
【００６８】
【数１４】

【００６９】
レンズと、Ｐ（０，Ｐｙ），Ｐ（Ｐｘ，Ｐｙ）をそれぞれ結ぶ直線のなす角度θｘを算出する。レンズとＰ（０，Ｐｙ）を結ぶ直線の長さＬＰは、次式のようになる。
【００７０】
【数１５】

【００７１】
であるから、実座標Ｒｘが算出できる。
【００７２】
【数１６】

【００７３】
以上のようにしてすべての輪郭線上にあって、カメラ座標に対して算出した実座標を、標尺２０の傾きをもとに回転補正する。これにより撮影したコンクリート柱が傾いていた場合や角度をつけて撮影した画像でもその理想軸をＹ軸とした世界座標が得られる。そしてカメラ座標系でのサンプル座標および補間座標から、世界座標系の曲線座標を得る。
【００７４】
図６に戻るが、第１１行程では、世界座標系の曲線座標を用いて近似曲線式を算出する行程（近似曲線式算出行程）である。
この近似曲線式は、鉄筋コンクリート柱の高さを入力値とすると、理想軸上の変位を出力値とし、世界座標上における実際の鉄筋コンクリート柱の描く曲線を表す式である。
【００７５】
すなわち、得られた世界座標系の曲線座標を用いて最小二乗法により多項式近似を行い、図４に示すように、鉄筋コンクリート柱１０の地際点を原点とし、標尺２０から得られた理想軸を高さ方向のＹ軸とし、輪郭線各高さにおける変位をＸ軸とする。そして高さＹと変位Ｘの近似曲線Ｘ＝ｆ（Ｙ）を結果として出力する。
近似曲線Ｘ＝ｆ（Ｙ）は、例えば、次式のようになる。
【００７６】
【数１７】

【００７７】
この行程により、画像の分解能による誤差のばらつきを軽減し、装柱機器などによる隠れた輪郭線の推定を可能とし、滑らかな輪郭線を表す近似曲線式を得ることができる。
【００７８】
行程１２では、予め鉄筋コンクリート柱１０の装柱状態や土質状態からシミュレーション解析された理論曲線と重ねてグラフ出力することによりその安全を評価する。
行程１３では、解析の結果となるデータを出力する。例えば、ディスプレイ表示・印刷などである。
支持柱曲線測定方法および支持柱曲線測定システムはこのようなものである。
【００７９】
【発明の効果】
本発明によれば、定量的な輪郭曲線を表す近似曲線式を算出して既設の鉄筋コンクリート柱のような支持物の変位を簡易かつ厳密に解析できるようにし、解析結果から支持物の耐性および負荷状態を診断するための支持柱曲線測定方法および支持柱曲線測定システムを提供することができる。
鉄筋コンクリート柱の製造過程における耐性試験を簡素化する他、輪郭曲線を非破壊で解析することができ、敷設後の経年劣化および過負荷状態の診断に利用することができる。
【図面の簡単な説明】
【図１】本発明の実施形態の支持柱曲線測定システムのシステム構成図である。
【図２】鉄筋コンクリート柱への標尺の設置を説明する説明図である。
【図３】
標尺の構成図である。
【図４】ｚ方向に眺めたときの鉄筋コンクリート柱を示す図である。
【図５】ｘ方向に眺めたときの鉄筋コンクリート柱を示す図である。
【図６】支持柱曲線計測の各行程を説明するフローチャートである。
【図７】画像データの回転変換を説明する説明図である。
【図８】撮像手段のカメラ姿勢の算出原理を説明する説明図である。
【図９】輪郭線の抽出範囲の切り出しを説明する説明図である。
【図１０】輪郭線の抽出を説明する説明図である。
【図１１】座標変換を説明する説明図である。
【図１２】別方向からの座標変換を示す図である。
【符号の説明】
１ 解析手段
２ 伝送路
３ 撮像手段
１０ 鉄筋コンクリート柱
２０ 標尺
２１，２２，２３ 特徴点
３０ 固定治具[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a supporting column curve measuring method and a supporting column curve measuring system for simply and strictly analyzing the coordinates of a contour curve drawn by a support such as a reinforced concrete column by a load.
[0002]
[Prior art]
The support includes various types such as wooden pillars, steel columns, reinforced concrete columns, composite columns, and steel towers. The following description will be made by taking the most commonly used reinforced concrete columns at present as an example.
A first prior art technique for measuring a support column curve in a reinforced concrete column includes a resistance test in a manufacturing process of the reinforced concrete column.
In this resistance test, for example, the ground side is fixed by laying down a reinforced concrete column, a load is applied to the fixed reinforced concrete column, the displacement at each height position from when no load is applied is measured by a displacement meter, and the whole is measured. The tolerance was measured from the degree of curvature.
[0003]
In addition, as a second prior art for measuring a supporting column curve of a reinforced concrete column, displacement measurement at each height of an existing reinforced concrete column can be mentioned. Since the displacement is directly measured on an existing reinforced concrete column that is curved by a load such as an electric wire, the displacement according to the actual situation can be measured. In this displacement measurement, coordinates are measured using a surveying instrument.
[0004]
Further, as a third prior art for measuring a support column curve of a reinforced concrete column, Patent Document 1 (name of the invention: a device for measuring the degree of curvature of a utility pole) according to a patent invention is known. This patent invention analyzes image data to measure the degree of curvature of a utility pole.
[0005]
[Patent Document 1]
Patent No. 3043910 (paragraphs 0007 to 0023, FIGS. 1 to 15)
[0006]
[Problems to be solved by the invention]
In recent years, there is an increasing need for a technique for simply and strictly measuring the contour curve of an existing reinforced concrete column.
The resistance test in the process of manufacturing a reinforced concrete column, which is the first prior art described above, can perform strict measurement, but has a problem of high cost and labor, and is not a simple measurement method. Furthermore, it was not possible to measure the contour curves of existing reinforced concrete columns that required measurement.
[0007]
In addition, the second prior art described above is to measure displacement at each height of an existing reinforced concrete column due to a load, and can perform measurement on an existing reinforced concrete column. Although it is possible, surveying requires specialized knowledge and is very time-consuming, and is not a simple measurement method. As a result, there is a problem that the displacement measurement at each height of the reinforced concrete column due to the load applied after the laying is performed by a non-quantitative measurement judgment by visual observation, and accurate measurement may not be performed.
[0008]
Furthermore, the measurement of the degree of curvature of a utility pole by image analysis described in Patent Document 1 of the third prior art described above analyzes image data and is compared with the first and second prior arts. Although this is very simple, there is a problem that, for example, the angle of view and the photographing position are not particularly taken into consideration, and the degree of curvature is a combination of straight lines.
[0009]
In summary, the first to third prior arts are either strict or not simple (first and second prior arts) or simple but not strict (third prior art). Was. Therefore, there is a demand for a practical method capable of simply and strictly analyzing the displacement of an existing reinforced concrete column.
[0010]
Therefore, the present invention has been made in order to solve the above problems, and an object of the present invention is to calculate an approximate curve equation representing a quantitative contour curve and calculate the displacement of a support such as an existing reinforced concrete column. An object of the present invention is to provide a support column curve measurement method and a support column curve measurement system for enabling simple and strict analysis, and for diagnosing the resistance and load state of a support from the analysis results.
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the supporting column curve measuring method of the present invention provides, as described in claim 1,
A feature point image coordinate calculation step of detecting a feature point included in the image data and calculating a feature point image coordinate for image data obtained by capturing the support with the plurality of feature points by the imaging unit;
A posture data calculation step of calculating posture data of the imaging means from the feature point image coordinates;
An ideal axis calculation step of calculating an ideal axis of the linear support from the feature point image coordinates,
A sample point input process for calculating sample coordinates by inputting sample points on the contour line of the support on the image data;
An interpolation coordinate calculation step of calculating interpolation coordinates by interpolating between sample coordinates on the contour line;
A curve coordinate calculation step of converting the sample coordinates and the interpolation coordinates represented in the camera coordinate system into curve coordinates in the world coordinate system by using the attitude data of the imaging means, and
An approximate curve expression calculation step of calculating an approximate curve expression using curve coordinates in the world coordinate system, and a curve at a coordinate at a predetermined position on an ideal axis is specified by the approximate curve expression.
[0012]
Further, according to the supporting column curve measuring method of the present invention,
The support column curve measuring method according to claim 1,
It is characterized in that the support column curve measurement is performed using image data obtained by correcting and converting optical distortion inherent to the imaging means in advance.
[0013]
Further, according to the supporting column curve measuring method of the present invention,
In the supporting column curve measuring method according to claim 1 or 2,
The feature points of the image data are feature points attached to a staff staff fixed along the contour line from the ground of the support.
[0014]
Further, the support column curve measuring system of the present invention, as described in claim 4,
An analysis means for performing a support curve measurement by performing each step of the support column curve measurement method according to any one of claims 1 to 3 is provided.
[0015]
Further, the support column curve measuring system of the present invention, as described in claim 5,
Imaging means for photographing the entire support and outputting image data;
The support curve measurement is performed by performing each step of the support column curve measurement method according to any one of claims 1 to 3 using image data read out from the imaging unit via a transmission path. Analysis means;
It is characterized by having.
[0016]
[Action]
In the method for analyzing the contour curve of a support (reinforced concrete column) according to the present invention, the entire image of the support is photographed in an arbitrary posture, and the camera posture of the image data and further the distortion due to optical distortion (when necessary) are corrected. Then, an approximate curve expression of the world coordinate system drawn by the outline of the support is calculated. Thus, the contour curve drawn by the support is measured simply and strictly.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the supporting column curve measuring method and the supporting column curve measuring system of the present invention will be collectively described with reference to the drawings. FIG. 1 is a system configuration diagram of a support column curve measurement system of the present embodiment. In the present embodiment, a reinforced concrete column will be described below as a specific example of the support (synonymous with the support column).
[0018]
There are two types of support column curve measurement systems. For example, a support column curve measurement system (1) shown in FIG. 1 is a system including only the analysis unit 1 and is connected to the imaging unit 3 via the transmission path 2. The analysis means 1 may take in the image data and measure the supporting column curve by image processing.
[0019]
For example, an image of an existing reinforced concrete column is acquired by a digital camera (imaging means 3) at the site to obtain image data, and a cable (transmission path 2) is later connected to a computer (analyzing means 1) installed at another location. It is assumed that the analysis work is performed by an analysis program created based on the support column curve measuring method of the present invention.
Alternatively, a camera-equipped mobile phone (imaging means 3) captures an image of an existing support to acquire image data, which is later transferred to a remote computer (analysis device) via a mobile communication line / data line (transmission line 2). It is also assumed that it is taken into the means 1).
[0020]
Further, as in a supporting column curve measuring system (2) shown in FIG. 1, a system in which the analyzing means 1, the transmission path 2, and the imaging means 3 are integrated may be used.
For example, a support column curve measuring system such as a portable computer or a portable device in which a camera (imaging means 3) and a computer (analyzing means 1) are integrated is assumed.
In any of the support column curve measurement systems (1) and (2), the analysis means 1 is connected to the imaging means 3 via the transmission path 2 so that the image data taken by the imaging means 3 can be read.
[0021]
Subsequently, a supporting column curve measuring method using such a supporting column curve measuring system will be described with reference to the drawings. FIG. 2 is an explanatory view for explaining the setting of a staff on a reinforced concrete pillar, FIG. 3 is a diagram showing a staff structure, FIG. 4 is a view showing a reinforced concrete pillar when viewed in a z direction, and FIG. 5 is a view when viewed in an x direction. It is a figure showing a reinforced concrete pillar. FIG. 6 is a flowchart for explaining each process of the support column curve measurement, FIG. 7 is an explanatory diagram for explaining the rotation conversion of the image data, FIG. 8 is an explanatory diagram for explaining the principle of calculating the camera attitude of the imaging means, and FIG. FIG. 10 is an explanatory diagram illustrating extraction of a contour extraction range, FIG. 10 is an explanatory diagram illustrating extraction of a contour line, FIG. 11 is an explanatory diagram illustrating coordinate conversion, and FIG. 12 is a diagram illustrating coordinate conversion from another direction. is there.
[0022]
Each process of the support column curve measurement is a process as shown in FIG.
Step 1 is a step of fixing a staff staff to a reinforced concrete column before imaging.
Specifically, as shown in FIG. 2, the staff 20 is fixed to the reinforced concrete column 10 by a fixing jig 30. The staff 20 is formed in a straight bar shape as shown in FIG. 3, and a total of three characteristic points 21, 22, and 23 are marked at both ends and a middle thereof at equal intervals. It becomes an index point. The staff 20 is to fix the staff 20 along the ground curve on the contour curve for measuring the bending of the reinforced concrete column 10, and is adjusted to stand vertically from the ground using a level gauge or the like. Is done.
[0023]
Referring back to FIG. 6, step 2 is a step in which reinforced concrete columns are imaged by the imaging means to obtain image data. The following description is based on the assumption that a digital camera is used as an imaging unit, a cable is used as a transmission path, and a computer is used as an analysis unit.
[0024]
As an example, as shown in FIG. 5, the digital camera (imaging means 3) is directed along the z-axis direction, and the reinforced concrete pillar 10 is arbitrarily set at an arbitrary photographing distance and photographing angle at which the entire reinforced concrete column 10 can be accommodated in one screen. The pillar 10 and the staff 20 are imaged to obtain image data.
[0025]
Referring back to FIG. 6, step 3 is a step of inputting image data output from the digital camera (imaging means 3) to the computer (analyzing means 1). In this case, a cable (transmission path 2) is connected between the digital camera and the computer, and image data is taken in via the cable.
[0026]
Hereinafter, the steps 4 to 13 are steps performed by the computer (the analysis unit 1). Step 4 is a step in which optical data inherent to the imaging means is converted into image data that has been corrected and converted in advance. The optical distortion of the lens of the digital camera (imaging means 3) is analyzed in advance, the registered data is read, and the optical distortion of the input image data is corrected and converted to generate image data. This reduces analysis errors due to optical distortion. In some cases, the optical distortion is so small as to be negligible. In such a case, this step can be omitted. As a result, it is assumed that image data as shown in FIG. 7A is generated.
[0027]
Step 5 is a step (feature point image coordinate calculation step) of detecting three feature points 21, 22, and 23 of staff staff 20 included in image data by image processing and calculating feature point image coordinates.
For example, feature point image coordinates at which the feature points 21, 22, and 23 are located are extracted from the image data shown in FIG. In this case, the center of gravity of each feature point is specified as feature point image coordinates.
[0028]
In this step 5, the feature point image coordinates of the feature points 21, 22, and 23 are further analyzed, and if it is determined that the image data is inclined, rotation conversion is performed to rotate the image data around the optical axis coordinates. As the rotation angle, for example, a rotation angle may be selected such that all the x-coordinates of the feature point image coordinates of the converted feature points 21, 22, and 23 match. Here, the feature point image coordinates are the coordinates after the rotation transformation. The image data that has been rotationally converted in this way is an image in which the staff 20 is vertical as shown in FIG.
[0029]
Returning to FIG. 6, in step 6, the digital coordinates of the height, photographing distance, and photographing angle of the digital camera (imaging means 3) are obtained from the characteristic point image coordinates of the three characteristic points 21, 22, and 23 of the staff staff 20. This is a process of calculating the posture data of the camera (the imaging unit 3) (posture data calculation process). A method for calculating the posture of the digital camera will be described with reference to FIG.
[0030]
The feature point image coordinates of the feature points 21, 22, and 23 obtained in the previous step 5 are the coordinates of points P ', A', and B 'in the camera coordinate system, as shown in FIG. The values are '(x, y), A' (x, y), and B '(x, y).
Also, (1) the focal length f of the lens analyzed in advance, (2) the optical axis coordinate t (x, y), which is the intersection of the optical axis and the camera coordinate system, and (3) one pixel of the CCD of the digital camera. Dimensions (length, width), (4) The ratio k between the actual size PA of the staff 20 and the size AB is known and given.
Furthermore, angles γ (∠POT), α (∠POA), and β (∠POB) between the optical axis and each feature point in the camera coordinate system are obtained. These are calculated by the arc tangent of the distance from the optical axis coordinates (t) to the feature point coordinates (P ′, A ′ or B ′) and the focal length.
[0031]
From these values, posture data of the digital camera such as (1) photographing angle θ, (2) photographing distance OR, and (3) camera height RB from the ground to the digital camera are calculated. The following simultaneous equation is established under the condition of PA = kAB.
[0032]
(Equation 1)

[0033]
Here, ρ = θ−γ, which is the angle between the horizontal line OR passing through the digital camera and the straight line OP.
Next, a derivation process for solving the above simultaneous equations will be described. When PA and AB are eliminated from the above simultaneous equations, the following equations are obtained.
[0034]
(Equation 2)

[0035]
When converted by the addition theorem, the following equation is obtained.
[0036]
[Equation 3]

[0037]
Here, variable conversion is performed as shown by the following equation.
[0038]
(Equation 4)

[0039]
When this variable is used, the following equation is obtained.
[0040]
(Equation 5)

[0041]
In summary, it is as shown in the following equation.
[0042]
(Equation 6)

[0043]
Here, p is a real number, and since (p ² +1) is not 0, it can be erased. In summary, it is as shown in the following equation.
[0044]
(Equation 7)

[0045]
Further, the relationship is converted as follows from the relationship of θ = γ−ρ and the relationship of the variables by the above Expression 4.
[0046]
(Equation 8)

[0047]
Thus, (1) the photographing angle θ is calculated.
Subsequently, (2) the shooting distance OR is calculated. Taking the ratio between PA and RP gives:
[0048]
(Equation 9)

[0049]
This satisfies the following relationship.
[0050]
(Equation 10)

[0051]
Thus, (2) the shooting distance OR is calculated.
Subsequently, (3) the camera height RB is calculated. The camera height RB satisfies the following equation.
[0052]
(Equation 11)

[0053]
Here, RP = OR · tan ρ, and PB is the length of the staff staff 20, which can be calculated from a known value.
In this way, the camera height RB with respect to the ground B is calculated.
As described above, the posture data of the digital camera such as (1) the photographing angle θ, (2) the photographing distance OR, and (3) the camera height RB from the ground to the digital camera are calculated.
[0054]
Now, return to FIG.
Step 7 is a step of calculating the ideal axis of the reinforced concrete column 10 on a straight line (that is, not curved) in the no-load state from the feature point image coordinates of the three feature points 21, 22, and 23 of the staff 20. Axis calculation process).
Since the feature point is a point drawn on the staff 20, a true ideal axis is defined by back calculation based on an angle formed by a straight line connecting the staff 20 with the outline and a straight line connecting the feature point centroid.
[0055]
Step 8 is a step of inputting sample points on the outline of the reinforced concrete column 10 on the image data and calculating sample coordinates (sample point input step).
In this process, image data is displayed on a display device (not shown) of the computer (analyzing means 1), and the user points using a pointing device such as a mouse, and several sample points on the contour line of the reinforced concrete column 10 are formed at the end. Enter up to the point.
[0056]
Since the reinforced concrete column 10 in the laid state has various mounting devices and cables and has a portion where the outline is hidden, a portion where the outline can be clearly seen is input as a sample point. Enter 3 or more points evenly up to the top of the reinforced concrete column. The sample point is a pixel whose outline can be visually observed except for a portion hidden by a mounting device or a cable. Sample coordinates are calculated for such sample points.
[0057]
Step 9 is a step of calculating interpolation coordinates by interpolating between sample coordinates on the contour line (interpolation coordinate calculation step).
In this process, the contour between the input sample points is extracted and interpolated by image processing. In other words, by interpolating and increasing the number of sample points input at several places, it is possible to enhance the consistency of the approximate curve expression obtained in step 11 described later.
[0058]
Specifically, as shown in FIG. 9, a rectangular outline from each sample point to the next sample point is cut out from the ground to the top. Here, the extraction range of the contour is a rectangle such that the straight line connecting the sample points is the axis of symmetry. An outline is traced in each of the extracted extraction ranges, and a single outline is generated by combining them.
[0059]
In addition, by taking into account the directionality of the outline from the inclination of the preceding and following sample points, the width a of the extraction range is limited so that the outline does not significantly warp in the wrong direction, thereby achieving stable extraction.
However, since the width of the extraction range is considered to be one pixel, that is, almost a straight line, the portion where the inclination difference θ between the input points hardly changes is directly subjected to the straight line interpolation.
[0060]
Next, a procedure for following the contour in each of the extracted ranges extracted in this manner will be described with reference to FIG.
First, rotation of the cut rectangular image is corrected so that the axis of the rectangular image becomes vertical, and the image is converted into an edge image representing a density change in the horizontal direction. Using this edge image, the pixel with the strongest edge among the three pixels (upper left, upper, upper right) located above the sample point located on the ground side, that is, the lower part, is defined as the contour line.
[0061]
Further, a pixel having the strongest edge among the three pixels located above the pixel is defined as a contour line. If a strong edge does not exist, such as a contour line is hidden by a pillar device, the process proceeds upward. By repeating this, the process reaches the next sample point and one contour line is generated. This is restored based on the angle at the time of rotation correction, and the contour lines generated in each extraction range are combined to generate the entire contour line.
[0062]
Returning to FIG. 6, a process 10 is a process in which the sample coordinates and the interpolation coordinates expressed in the camera coordinate system using the attitude data of the imaging unit are set to the world in which the ideal axis obtained in the process 7 is the Y axis in the height direction. This is a process (curve coordinate calculation process) calculated by converting the coordinates into curve coordinates in a coordinate system.
[0063]
The image coordinates corresponding to the contour are converted into camera coordinates using the optical axis position of the lens as the origin.
11, as shown in Figure 12, previously photographing distance Lz calculated in step 6, the camera height Cy and imaging angle θ by using the _A coordinate P in the camera coordinate system (Px, Py) from the world coordinate system Convert to coordinates R (Rx, Ry).
First, an angle θy between a straight line connecting the Y-axis coordinate P (0, Py) of the camera coordinate system and the lens and the optical axis is calculated.
[0064]
(Equation 12)

[0065]
The actual coordinates Ry are calculated from this θy.
[0066]
(Equation 13)

[0067]
The distance Ct between the lens and the real coordinates R (0, Ry) is calculated.
[0068]
[Equation 14]

[0069]
An angle θx formed by a straight line connecting the lens with P (0, Py) and P (Px, Py) is calculated. The length LP of a straight line connecting the lens and P (0, Py) is expressed by the following equation.
[0070]
(Equation 15)

[0071]
Therefore, the actual coordinates Rx can be calculated.
[0072]
(Equation 16)

[0073]
The rotation of the real coordinates on all the contour lines calculated with respect to the camera coordinates as described above is corrected based on the inclination of the staff 20. As a result, world coordinates with the ideal axis as the Y axis can be obtained even when the concrete column is tilted or an image is shot at an angle. Then, curve coordinates in the world coordinate system are obtained from the sample coordinates and the interpolation coordinates in the camera coordinate system.
[0074]
Referring back to FIG. 6, the eleventh step is a step of calculating an approximate curve equation using curve coordinates in the world coordinate system (an approximate curve equation calculation step).
This approximate curve equation is an equation that represents a curve drawn by an actual reinforced concrete column in world coordinates, using the displacement on the ideal axis as an output value, when the height of the reinforced concrete column is set as an input value.
[0075]
That is, a polynomial approximation is performed by the least squares method using the obtained curve coordinates of the world coordinate system, and as shown in FIG. The Y-axis in the height direction is set, and the displacement at each height of the contour line is set as the X-axis. Then, an approximate curve X = f (Y) of the height Y and the displacement X is output as a result.
The approximate curve X = f (Y) is, for example, as follows.
[0076]
[Equation 17]

[0077]
By this process, it is possible to reduce the variation in error due to the resolution of the image, to enable estimation of a hidden contour line by a pillar device or the like, and to obtain an approximate curve equation representing a smooth contour line.
[0078]
In the process 12, the safety is evaluated by outputting a graph superimposed on a theoretical curve that has been simulated and analyzed from the mounting condition and soil condition of the reinforced concrete column 10 in advance.
In step 13, data as a result of the analysis is output. For example, display / printing, etc.
The supporting column curve measuring method and the supporting column curve measuring system are such.
[0079]
【The invention's effect】
According to the present invention, an approximate curve equation representing a quantitative contour curve is calculated so that displacement of a support such as an existing reinforced concrete column can be easily and strictly analyzed, and the resistance and load of the support are determined from the analysis result. A support column curve measurement method and a support column curve measurement system for diagnosing a condition can be provided.
In addition to simplifying the resistance test in the manufacturing process of reinforced concrete columns, the profile curve can be analyzed in a non-destructive manner, and can be used for diagnosis of aging deterioration and overload after laying.
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of a support column curve measurement system according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram illustrating installation of a staff on a reinforced concrete pillar.
FIG. 3
It is a lineblock diagram.
FIG. 4 is a diagram showing a reinforced concrete column when viewed in the z direction.
FIG. 5 is a view showing a reinforced concrete column when viewed in the x direction.
FIG. 6 is a flowchart illustrating each process of support column curve measurement.
FIG. 7 is an explanatory diagram illustrating rotation conversion of image data.
FIG. 8 is an explanatory diagram illustrating a principle of calculating a camera attitude of an imaging unit.
FIG. 9 is an explanatory diagram illustrating extraction of a contour line extraction range.
FIG. 10 is an explanatory diagram illustrating extraction of a contour line.
FIG. 11 is an explanatory diagram illustrating coordinate conversion.
FIG. 12 is a diagram showing coordinate conversion from another direction.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Analysis means 2 Transmission path 3 Imaging means 10 Reinforced concrete pillar 20 Staff 21, 22, 23 Feature point 30 Fixing jig

Claims (5)

For image data obtained by imaging the support with a plurality of feature points by the imaging means,
A feature point image coordinate calculation step of detecting feature points included in the image data and calculating feature point image coordinates;
A posture data calculation step of calculating posture data of the imaging means from the feature point image coordinates;
An ideal axis calculation step of calculating an ideal axis of the linear support from the feature point image coordinates,
A sample point input process for calculating sample coordinates by inputting sample points on the contour line of the support on the image data;
An interpolation coordinate calculation step of calculating interpolation coordinates by interpolating between sample coordinates on the contour line;
A curve coordinate calculation step of converting the sample coordinates and the interpolation coordinates represented in the camera coordinate system into curve coordinates in the world coordinate system by using the attitude data of the imaging means, and
An approximate curve expression calculation step of calculating an approximate curve expression using the curve coordinates in the world coordinate system;
A method of measuring a support column curve, wherein a curve at a predetermined position on an ideal axis is specified by an approximate curve equation. The support column curve measuring method according to claim 1,
A method for measuring a support column curve using image data obtained by correcting and converting optical distortion inherent to an imaging unit in advance. In the supporting column curve measuring method according to claim 1 or 2,
The method according to claim 1, wherein the characteristic points of the image data are characteristic points attached to a staff staff fixed along the contour from the ground of the support. A support column curve measurement system, comprising: an analysis unit that performs each step of the support column curve measurement method according to any one of claims 1 to 3 to perform a support curve measurement. Imaging means for photographing the entire support and outputting image data;
The support curve measurement is performed by performing each step of the support column curve measurement method according to any one of claims 1 to 3 using image data read out from the imaging unit via a transmission path. Analysis means;
A support column curve measuring system, comprising:

Images