JP2010071722A - Method and device for inspecting unevenness flaws - Google Patents

Method and device for inspecting unevenness flaws Download PDF

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JP2010071722A
JP2010071722A JP2008237601A JP2008237601A JP2010071722A JP 2010071722 A JP2010071722 A JP 2010071722A JP 2008237601 A JP2008237601 A JP 2008237601A JP 2008237601 A JP2008237601 A JP 2008237601A JP 2010071722 A JP2010071722 A JP 2010071722A
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area camera
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JP5488953B2 (en
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Tomohiro Kuroiwa
朋広 黒岩
Yoshihiro Furuya
順弘 古家
Yusuke Konno
雄介 今野
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Nippon Steel Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device for inspecting unevenness flaws for accurately inspecting, over the whole width, the unevenness flaws existing on a surface of an object to be inspected, such as, slab using a simple light source. <P>SOLUTION: The surface of the object 1 to be inspected moving in a longitudinal direction is irradiated with a linear laser beam 4 of the width direction from a laser irradiating machine 3, and the irradiated position is photographed obliquely upside by an area camera 5, having a linear field of view of a predetermined width. An unevenness information arithmetic means 6 calculates unevenness information on the surface of the object 1 to be inspected, based on the variations at reflecting position of the photographed linear laser beam 4, and a luminance image arithmetic means 7 for sequentially and widthwise calculating the average value of a plurality of longitudinal pixels of the object 1 to be inspected, with respect to the image of the area camera, and calculates surface luminance image information. Unevenness flaw on the surface of the object to be inspected is inspected based on both information, so that accurate inspection becomes possible. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は板状の被検査体の表面にレーザ光線を照射し、凹凸疵の検査を行う凹凸疵検査方法及び装置に関するものである。   The present invention relates to a method and an apparatus for inspecting an uneven surface by irradiating a surface of a plate-like object with a laser beam to inspect the uneven surface.

例えば製鉄工場において生産されるスラブや厚板鋼板などの表面には、様々な原因により皺や割れなどの凹凸疵が発生することがある。これらの凹凸疵はできるだけ上工程において検出することが好ましく、看過されて下工程に流れたり客先に出荷されたりすると、多数の不良品を発生させる可能性がある。従来は主として目視検査が行われていたが、検査基準が検査員によるため定性的となりばらつきが生じてしまうとともに、スラブ表面の模様やスケールのために見落としが生じ易い。そこで検査基準を定量的としばらつきをなくすとともに、見落としを防止するために、光学的に自動検査する技術が開発されている。   For example, uneven surfaces such as wrinkles and cracks may be generated on the surface of slabs and thick steel plates produced in an iron factory for various reasons. It is preferable to detect these irregularities in the upper process as much as possible. If the irregularities are overlooked and flow to the lower process or are shipped to the customer, a large number of defective products may be generated. Conventionally, visual inspection has been mainly performed. However, since the inspection standard is qualitative and inconsistent due to the inspector, variations occur, and oversight is likely to occur due to the pattern and scale of the slab surface. Therefore, a technique for automatically inspecting optically has been developed in order to make the inspection standard quantitative and eliminate variations, and to prevent oversight.

例えば特許文献１には、スラブの表面に直線的なスリット光と平面的な広がりを持つ2次元光とを同時に照射し、スラブ表面からの反射光を単一のカメラで撮影したうえで前記２種類の光線の波長差を利用して画像を分離し、スリット光によって光切断法による凹凸形状を検出し、2次元光によって表面疵を検出する方法が提案されている。しかしこの方法では２種類の光源を必要とするので光源のメンテナンスに多くの手数を要すること、2次元光は光源からの距離によって反射点の照度が変化してしまうため、スラブの幅方向全体にわたる均一精度の検査が行えないこと、２種類の光源の焦点合わせが難しいことなどの多くの問題があり、実用性に問題があった。
特開平９−１５２３２２号公報 For example, in Patent Document 1, the surface of the slab is irradiated with a linear slit light and a two-dimensional light having a two-dimensional spread at the same time, and the reflected light from the surface of the slab is photographed with a single camera. A method has been proposed in which an image is separated using wavelength differences of various types of light, a concavo-convex shape by a light cutting method is detected by slit light, and a surface defect is detected by two-dimensional light. However, since this method requires two types of light sources, it requires a lot of work to maintain the light source, and since the illuminance at the reflection point of the two-dimensional light changes depending on the distance from the light source, it covers the entire width of the slab. There were many problems such as inability to perform inspection with uniform accuracy and difficulty in focusing two types of light sources, and there was a problem in practicality.
JP-A-9-152322

本発明は上記した従来の問題点を解決し、単一の光源によってスラブなどの被検査体の表面に存在する凹凸疵を全幅にわたり精度よく検査することができる凹凸疵検査方法及び装置を提供することを目的とするものである。   The present invention solves the above-described conventional problems and provides a method and apparatus for inspecting uneven wrinkles present on the surface of an object to be inspected such as a slab with a single light source with high accuracy over the entire width. It is for the purpose.

上記の課題を解決するためになされた本発明の凹凸疵検査方法は、長手方向に移動する被検査体の表面に幅方向の線状レーザ光を照射し、その照射位置を斜め上方から所定幅の線状視野を持つエリアカメラにより撮影し、撮影された線状レーザ光の反射位置の変動から被検査体の表面の凹凸情報を取得するとともに、そのエリアカメラの画像に対して長手方向の複数画素分の平均値を幅方向に順次算出して表面輝度画像情報を取得し、これら双方の情報に基づいて被検査体表面の凹凸疵を検査することを特徴とするものである。なお請求項２のように、被検査体が自発光する高温スラブである場合には、線状レーザ光として緑色レーザ光を用いることが好ましい。   In order to solve the above-described problems, the method for inspecting a wrinkle of the present invention irradiates the surface of an object to be inspected moving in the longitudinal direction with a linear laser beam in the width direction, and the irradiation position is obliquely upward from a predetermined width. The image of the surface of the object to be inspected is obtained from the change in the reflection position of the captured linear laser light, and a plurality of longitudinal images are taken with respect to the image of the area camera. Surface luminance image information is obtained by sequentially calculating an average value for pixels in the width direction, and the surface of the object to be inspected is inspected for irregularities on the surface thereof. As in claim 2, when the object to be inspected is a high-temperature slab that emits light, it is preferable to use green laser light as the linear laser light.

また請求項３のように、線状レーザ光の反射位置を、エリアカメラの画像中の各画素について長手方向の複数画素の輝度分布を重心演算することによって求め、エリアカメラの分解能を越える精度を得ることが好ましい。また請求項４のように、エリアカメラの画像に対して輝度の閾値を設定し、その閾値を超えた輝度の画素を演算の対象とすることが好ましい。   Further, as described in claim 3, the reflection position of the linear laser beam is obtained by calculating the centroid of the luminance distribution of a plurality of pixels in the longitudinal direction for each pixel in the image of the area camera, and the accuracy exceeding the resolution of the area camera is obtained. It is preferable to obtain. Further, as in claim 4, it is preferable that a luminance threshold value is set for the image of the area camera, and a pixel having luminance exceeding the threshold value is set as a calculation target.

また本発明の凹凸疵検査装置は、長手方向に移動する被検査体の表面に幅方向の線状レーザ光を照射するレーザ照射機と、その照射位置を斜め上方から撮影する所定幅の線状視野を持つエリアカメラと、このエリアカメラにより撮影された線状レーザ光の反射位置の変動から被検査体の表面の凹凸情報を演算する凹凸情報演算手段と、このエリアカメラの画像に対して長手方向の複数画素分の平均値を幅方向に順次算出して表面輝度画像情報を演算する輝度画像演算手段とを備えたことを特徴とするものである。   In addition, the uneven wrinkle inspection apparatus according to the present invention includes a laser irradiator that irradiates the surface of an object to be inspected in the longitudinal direction with a linear laser beam in the width direction, and a linear line with a predetermined width that captures the irradiation position obliquely from above. An area camera having a field of view, an unevenness information calculating means for calculating unevenness information on the surface of the object to be inspected from fluctuations in the reflection position of the linear laser light imaged by the area camera, and a longitudinal direction with respect to the image of the area camera Luminance image calculation means for calculating surface luminance image information by sequentially calculating an average value for a plurality of pixels in the direction in the width direction is provided.

本発明によれば、単一の線状レーザ光を被検査体の表面に幅方向に照射し、その反射光を受光したエリアカメラの画像によって光切断法による被検査体の表面の凹凸情報を取得するとともに、同一のエリアカメラの画像から表面輝度画像情報を取得し、これら双方の情報に基づいて被検査体表面の凹凸疵を検査する。このように本発明においては、目視検査を行う場合と同様の表面輝度画像情報を凹凸情報と併用して凹凸疵の検査を行えるので、スラブ表面に模様やスケールがあっても精度のよい検査が可能となる。また本発明においては、光源とカメラはそれぞれ単一であるためにメンテナンスや焦点合わせなどが容易である。また線状レーザ光を用いるので、被検査体の幅方向全体にわたる均一精度の検査が可能である。   According to the present invention, a single linear laser beam is irradiated in the width direction on the surface of the object to be inspected, and unevenness information on the surface of the object to be inspected by the light cutting method is obtained by an image of an area camera that receives the reflected light. While acquiring, surface brightness image information is acquired from the image of the same area camera, and the uneven | corrugated wrinkles on the to-be-inspected object surface are test | inspected based on both information. As described above, in the present invention, since the surface luminance image information similar to that in the case of visual inspection can be used in combination with the unevenness information, the uneven surface can be inspected. It becomes possible. In the present invention, since the light source and the camera are each single, maintenance and focusing are easy. Further, since linear laser light is used, it is possible to inspect with uniform accuracy over the entire width direction of the object to be inspected.

なお被検査体が自発光する高温スラブである場合には、請求項２のように線状レーザ光として緑色レーザ光を用いることにより、スラブ表面からの赤色光との識別が容易となり、正確な検査が可能となる。   When the object to be inspected is a high-temperature slab that emits light by itself, the green laser beam is used as the linear laser beam as in claim 2 so that it can be easily distinguished from the red light from the slab surface. Inspection is possible.

また光切断法においては線状レーザ光の反射位置の変動から被検査体の表面の凹凸を求めるため、エリアカメラの分解能が問題となるが、請求項３の手法を用いればエリアカメラの分解能を越える精度で検査が可能となる。さらに請求項４のようにエリアカメラの画像中の閾値を超えた輝度の画素を演算の対象とすることにより、線状レーザ光の情報のみを反射位置の算出に使用することが可能となり、外乱による誤差を低減できる。   Further, in the light cutting method, since the unevenness of the surface of the object to be inspected is obtained from the fluctuation of the reflection position of the linear laser beam, the resolution of the area camera becomes a problem. If the method of claim 3 is used, the resolution of the area camera is reduced. Inspection is possible with accuracy exceeding. Furthermore, as described in claim 4, by making pixels having luminance exceeding the threshold in the area camera image, only the information of the linear laser beam can be used for calculation of the reflection position, and disturbance The error due to can be reduced.

以下に本発明の好ましい実施形態を示す。なお以下の実施形態では被検査体はスラブであるがこれに限定されるものではなく、本発明は鋼板などの板状体の検査に広く適用可能である。   Preferred embodiments of the present invention are shown below. In the following embodiments, the object to be inspected is a slab. However, the present invention is not limited to this, and the present invention is widely applicable to inspection of plate-like bodies such as steel plates.

図１において１は被検査体であるスラブであり、搬送用ローラ２によって長手方向に移動している。３はこの被検査体１の表面に幅方向の線状レーザ光を照射するレーザ照射機である。被検査体１の表面における被検査体に対して長手方向の線状レーザ光４の幅は、例えば１〜２ｍｍ程度と細くしておくことが検査精度を高めるうえで好ましい。レーザ照射機３は図２に示すようにほぼ垂直下向きに設置されており、この実施形態では垂直面に対して約１０°の角度で設定されている。５は被検査体１の表面の照射位置を斜め上方から撮影する所定幅の線状視野を持つエリアカメラである。エリアカメラ５は被検査体１の表面からの線状レーザ光４の反射光を撮影するものである。エリアカメラ５の視野は被検査体１の全幅をカバーするようにしておく。エリアカメラ５の画像は、以下に述べるように凹凸情報演算手段６および輝度画像演算手段７によって演算処理される。これらの凹凸情報演算手段６および輝度画像演算手段７としてはコンピュータが用いられる。   In FIG. 1, reference numeral 1 denotes a slab that is an object to be inspected, which is moved in the longitudinal direction by a conveying roller 2. A laser irradiator 3 irradiates the surface of the inspection object 1 with a linear laser beam in the width direction. The width of the linear laser beam 4 in the longitudinal direction with respect to the object to be inspected on the surface of the object to be inspected 1 is preferably made thin, for example, about 1 to 2 mm in order to increase the inspection accuracy. As shown in FIG. 2, the laser irradiator 3 is installed substantially vertically downward. In this embodiment, the laser irradiator 3 is set at an angle of about 10 ° with respect to the vertical plane. Reference numeral 5 denotes an area camera having a linear visual field with a predetermined width for photographing the irradiation position on the surface of the inspection object 1 obliquely from above. The area camera 5 captures the reflected light of the linear laser light 4 from the surface of the inspection object 1. The visual field of the area camera 5 is set so as to cover the entire width of the object 1 to be inspected. The image of the area camera 5 is calculated by the unevenness information calculating means 6 and the luminance image calculating means 7 as described below. A computer is used as the unevenness information calculating means 6 and the luminance image calculating means 7.

これらのレーザ照射機３とエリアカメラ５と凹凸情報演算手段６とによって、光切断法による被検査体１の凹凸疵の検査が行われる。光切断法自体は公知の手法であり、図２に示すように、被検査体１の表面に深さＬの凹部があると、線状レーザ光４の反射位置が垂直方向に変動するため、角度θの方向から撮影した画像がＸだけ変化する。ここでＬ＝Ｘ/ｓｉｎθであることを利用して、エリアカメラ５の画像から被検査体１の表面の凹凸情報を取得する手法である。演算は凹凸情報演算手段６によって行われる。θはこの実施形態では４５°である。   The laser irradiator 3, the area camera 5, and the concavo-convex information calculation means 6 inspect the concavo-convex wrinkles of the inspected object 1 by a light cutting method. The light cutting method itself is a known technique, and as shown in FIG. 2, if there is a recess having a depth L on the surface of the object to be inspected 1, the reflection position of the linear laser beam 4 varies in the vertical direction. An image taken from the direction of the angle θ changes by X. Here, using the fact that L = X / sin θ, this is a method of acquiring unevenness information on the surface of the inspection object 1 from the image of the area camera 5. The calculation is performed by the unevenness information calculation means 6. In this embodiment, θ is 45 °.

この光切断法の精度はエリアカメラ５の画像の解像度に左右されることとなるが、エリアカメラ５の生画像は図３に示すようにそれぞれが輝度情報を持った画素の集合であり、このままでは画素のサイズ以下の検出精度を得ることができない。すなわち、図３の左側の図は横方向が被検査体１の幅方向、縦方向が被検査体１の長手方向を示し、点線で囲まれた正方形が各画素を示している。この図３の例ではＰ１位置の輝度がｌ４、Ｐ２位置の輝度がｌ２、Ｐ３位置の輝度がｌ３、Ｐ４位置の輝度がｌ４であり、最も輝度が高いのはＰ３位置である。このため線状レーザ光４の反射位置はＰ３位置付近にあることは分かるが、１画素のサイズ以下の精度は得られない。 The accuracy of this light cutting method depends on the resolution of the image of the area camera 5, but the raw image of the area camera 5 is a set of pixels each having luminance information as shown in FIG. Therefore, it is not possible to obtain detection accuracy below the pixel size. That is, in the diagram on the left side of FIG. 3, the horizontal direction indicates the width direction of the device under test 1, the vertical direction indicates the longitudinal direction of the device under test 1, and a square surrounded by a dotted line indicates each pixel. In the example of FIG. 3, the luminance at the P 1 position is l 4 , the luminance at the P 2 position is l 2 , the luminance at the P 3 position is l 3 , and the luminance at the P 4 position is l 4. P 3 is a position. Although it is understood that this order reflection position of the linear laser beam 4 in the vicinity of P 3 position, following accuracy is not obtained the size of one pixel.

そこでこの実施形態では、線状レーザ光４の反射位置を各画素について長手方向の複数画素の輝度分布を重心演算することによって求めた。まず輝度の閾値をｌｔｈ＝ｌｍａｘ×ｋｔｈの式により設定する。ここでｌｍａｘは輝度の最大値であり、ｋｔｈは定数である。図３では閾値ｌｔｈは輝度の最大値の約１/３に設定（ｋｔｈ＝１/３）されており、この閾値を超えた輝度の画素のみを演算の対象とする。ここでは被検査体１の長手方向に分布する４個の画素が演算対象となっている。 Therefore, in this embodiment, the reflection position of the linear laser beam 4 is obtained by calculating the center of gravity of the luminance distribution of a plurality of pixels in the longitudinal direction for each pixel. First, the threshold value of luminance is set by the formula l th = l max × k th . Here, l max is the maximum value of luminance, and k th is a constant. In FIG. 3, the threshold value l th is set to about 1/3 of the maximum luminance value (k th = 1/3), and only pixels having luminance exceeding this threshold value are subject to calculation. Here, four pixels distributed in the longitudinal direction of the inspection object 1 are to be calculated.

次に数１の式によって長手方向のレーザ照射位置（反射位置）Ｐｒｅを演算する。分子は長手方向の画素の位置Ｐｋにその画素の輝度ｌｋを掛けた値を１からｎまで積算したものであり、ここではｎ＝４である。分母は長手方向の画素の位置Ｐｋを１からｎまで積算した値であり、これによって長手方向の輝度分布の重心を演算することができる。演算結果は画素のサイズよりも小さいサブピクセルのレベルを示し、これによって画素のサイズ以下の精度で線状レーザ光４の反射位置を正確に求めることができる。具体的には、画素のサイズは例えば１．２ｍｍであるが、上記した重心演算を行うことにより０．４ｍｍの精度で反射位置の変動を求めることが可能となった。 Next, the laser irradiation position (reflection position) Pre in the longitudinal direction is calculated by the equation (1). The numerator is a value obtained by multiplying the pixel position P k in the longitudinal direction by the luminance l k of the pixel from 1 to n, where n = 4. The denominator is a value obtained by integrating the pixel positions P k in the longitudinal direction from 1 to n, whereby the center of gravity of the luminance distribution in the longitudinal direction can be calculated. The calculation result indicates the level of the sub-pixel smaller than the pixel size, whereby the reflection position of the linear laser beam 4 can be accurately obtained with an accuracy less than the pixel size. Specifically, the pixel size is, for example, 1.2 mm. However, by performing the above-described center-of-gravity calculation, it is possible to obtain the variation in the reflection position with an accuracy of 0.4 mm.

Figure 2010071722
Figure 2010071722

このように本発明では、エリアカメラ５の画像中に現れた線状レーザ光４の反射位置の変動に着目して被検査体１の表面の凹凸情報を取得するが、これとともに同一のエリアカメラ５の画像から輝度画像演算手段７によって表面輝度画像情報を取得し、これら双方の情報に基づいて被検査体表面の凹凸疵を検査する。具体的には、エリアカメラ５の画像は図３に示したように被検査体１の幅方向の直線であるが、各画素についてその輝度を被検査体１の長手方向に複数画素分ずつ順次平均して幅方向の輝度分布を求め、これを被検査体１の長手方向に繰り返すことによって平面状の被検査体１の表面輝度画像情報を得る。   As described above, in the present invention, the unevenness information on the surface of the inspected object 1 is acquired by paying attention to the change in the reflection position of the linear laser beam 4 appearing in the image of the area camera 5. Surface brightness image information is acquired from the image 5 by the brightness image calculation means 7 and the surface of the object to be inspected is inspected for unevenness on the basis of both pieces of information. Specifically, the image of the area camera 5 is a straight line in the width direction of the device under test 1 as shown in FIG. 3, but the luminance of each pixel is sequentially increased by a plurality of pixels in the longitudinal direction of the device under test 1. The luminance distribution in the width direction is obtained on average, and this is repeated in the longitudinal direction of the inspection object 1 to obtain surface luminance image information of the planar inspection object 1.

この平均輝度の演算は、数２の式によって行うことができる。分子は長手方向の画素の位置Ｐｋにその画素の輝度ｌｋを掛けた値を１からｎまで積算したものであり、これをｎで割ることによって平均輝度が求められる。ただしｎは必ずしも４に限定されるものではなく、線状レーザ光４の幅及びエリアカメラ５の分解能（画素のサイズ）によって適宜設定すべきである。 The calculation of the average luminance can be performed by the equation (2). The numerator is a value obtained by multiplying the pixel position P k in the longitudinal direction by the luminance l k of the pixel from 1 to n, and the average luminance is obtained by dividing this by n. However, n is not necessarily limited to 4, and should be appropriately set according to the width of the linear laser beam 4 and the resolution (pixel size) of the area camera 5.

Figure 2010071722
Figure 2010071722

このようにして得られた表面輝度画像情報は、従来の人の目による検査を行う場合と同様の画像であり、光切断法のみによっては検出しにくい表面欠陥を検出することができる。また表面輝度画像情報と光切断法による凹凸情報とを併用することによって、スラブ表面に模様やスケールが存在する場合にも、凹凸疵を正確に検出することができる。なお表面輝度画像情報から輝度が異常を示す位置及び大きさを特定できるので、全自動的に合否の判断を行わせることができるが、表面輝度画像情報はモニタに表示させ、熟練した検査員による確認を行わせることも可能である。   The surface luminance image information obtained in this way is an image similar to that in the case of conventional inspection by the human eye, and can detect surface defects that are difficult to detect only by the light cutting method. Further, by using the surface luminance image information and the unevenness information obtained by the light cutting method in combination, even when a pattern or scale exists on the surface of the slab, the uneven surface can be accurately detected. Since the position and size where the luminance is abnormal can be specified from the surface luminance image information, it is possible to make a pass / fail judgment fully automatically. However, the surface luminance image information is displayed on the monitor and can be obtained by a skilled inspector. It is also possible to make confirmation.

なお、被検査体１が赤色光を自発光する高温スラブである場合には、４の反射光が検出しにくくなるおそれがある。その場合には、波長が５３２ｎｍの緑色レーザ光を使用することにより、赤色光との識別が容易となる。さらにレーザ照射機３とエリアカメラ５とに熱線を反射するフィルタを取り付けるとともに、エリアカメラ５に帯域通過フィルター（バンドパスフィルター：BPF）を取付けて、光の波長に応じて光の検出情報を選択的に通過させたり遮断することができるようにしておけば、高温スラブからの赤色光を遮断できるのでより好ましい検出精度を得ることができる。   In addition, when the to-be-inspected object 1 is a high temperature slab which self-emits red light, there exists a possibility that the reflected light of 4 may become difficult to detect. In that case, the green laser light having a wavelength of 532 nm is used, so that it can be easily distinguished from the red light. Furthermore, a filter that reflects heat rays is attached to the laser irradiator 3 and the area camera 5, and a band pass filter (band pass filter: BPF) is attached to the area camera 5 to select light detection information according to the light wavelength. If it can be allowed to pass through or be blocked, red light from the high-temperature slab can be blocked, so that more preferable detection accuracy can be obtained.

以上に説明したように、本発明においては光切断法による凹凸疵の検査を行うためのレーザ照射機とエリアカメラとを用い、エリアカメラの画像を被検査体の長手方向に複数画素分ずつ順次平均して表面輝度画像情報を演算することにより表面輝度画像情報を取得し、これら双方の情報に基づいて被検査体表面の凹凸疵を検査する。このため、目視検査を行う場合と同様の表面輝度画像情報を凹凸情報と併用して凹凸疵の検査を行えるので、スラブ表面に模様やスケールがあっても精度のよい検査が可能となる。また光源とカメラはそれぞれ単一であるためにメンテナンスが容易となり、また従来のような複数光源の焦点合わせなどは不要となるうえ、線状レーザ光を用いるために被検査体の全幅にわたり均一精度での検査が可能となる。   As described above, in the present invention, a laser irradiator and an area camera for inspecting uneven ridges by a light cutting method are used, and an image of the area camera is sequentially provided for a plurality of pixels in the longitudinal direction of the object to be inspected. The surface luminance image information is obtained by calculating the surface luminance image information on the average, and the surface of the object to be inspected is inspected for unevenness on the basis of both pieces of information. For this reason, since the same surface luminance image information as in the case of visual inspection can be used in combination with the unevenness information, the uneven surface can be inspected, so that even if there is a pattern or scale on the slab surface, an accurate inspection can be performed. In addition, since the light source and the camera are each single, maintenance is easy, and focusing of multiple light sources as in the past is not required, and since linear laser light is used, uniform accuracy over the entire width of the object to be inspected Inspection at can be performed.

本発明の検査方法を説明する概念的な斜視図である。It is a notional perspective view explaining the inspection method of the present invention. 光切断法の説明図である。It is explanatory drawing of a light cutting method. カメラ画像とその輝度分布を示す説明図である。It is explanatory drawing which shows a camera image and its luminance distribution.

符号の説明Explanation of symbols

１ 被検査体
２ 搬送用ローラ
３ レーザ照射機
４ 線状レーザ光
５ エリアカメラ
６ 凹凸情報演算手段
７ 輝度画像演算手段 DESCRIPTION OF SYMBOLS 1 Inspection object 2 Roller for conveyance 3 Laser irradiation machine 4 Linear laser beam 5 Area camera 6 Concavity and convexity information calculation means 7 Luminance image calculation means

Claims (5)

長手方向に移動する被検査体の表面に幅方向の線状レーザ光を照射し、その照射位置を斜め上方から所定幅の線状視野を持つエリアカメラにより撮影し、撮影された線状レーザ光の反射位置の変動から被検査体の表面の凹凸情報を取得するとともに、そのエリアカメラの画像に対して長手方向の複数画素分の平均値を幅方向に順次算出して表面輝度画像情報を取得し、これら双方の情報に基づいて被検査体表面の凹凸疵を検査することを特徴とする凹凸疵検査方法。   The surface of the object to be inspected moving in the longitudinal direction is irradiated with a linear laser beam in the width direction, and the irradiation position is photographed with an area camera having a linear field of view of a predetermined width obliquely from above. Information on the surface of the object to be inspected from fluctuations in the reflection position of the object, and the surface luminance image information is obtained by sequentially calculating the average value of a plurality of pixels in the longitudinal direction in the width direction for the image of the area camera. And a method for inspecting an uneven surface on the surface of the object to be inspected based on both of the information. 被検査体が自発光する高温スラブであり、線状レーザ光が緑色レーザ光であることを特徴とする請求項１記載の凹凸疵検査方法。   2. The method for inspecting concavo-convex wrinkles according to claim 1, wherein the object to be inspected is a high-temperature slab that emits light by itself, and the linear laser beam is a green laser beam. 線状レーザ光の反射位置を、エリアカメラの画像中の各画素について長手方向の複数画素の輝度分布を重心演算することによって求め、エリアカメラの分解能を越える精度を得ることを特徴とする請求項１記載の凹凸疵検査方法。   The reflection position of the linear laser light is obtained by performing a centroid calculation on the luminance distribution of a plurality of pixels in the longitudinal direction for each pixel in the image of the area camera, and an accuracy exceeding the resolution of the area camera is obtained. 1. The method for inspecting uneven wrinkles according to 1. エリアカメラの画像に対して輝度の閾値を設定し、その閾値を超えた輝度の画素を演算の対象とすることを特徴とする請求項１記載の凹凸疵検査方法。   2. The method for inspecting an irregularity wrinkle according to claim 1, wherein a threshold value of luminance is set for an image of an area camera, and pixels having a luminance exceeding the threshold value are subjected to calculation. 長手方向に移動する被検査体の表面に幅方向の線状レーザ光を照射するレーザ照射機と、その照射位置を斜め上方から撮影する所定幅の線状視野を持つエリアカメラと、このエリアカメラにより撮影された線状レーザ光の反射位置の変動から被検査体の表面の凹凸情報を演算する凹凸情報演算手段と、このエリアカメラの画像に対して長手方向の複数画素分の平均値を幅方向に順次算出して表面輝度画像情報を演算する輝度画像演算手段とを備えたことを特徴とする凹凸疵検査装置。   A laser irradiator that irradiates the surface of the object to be inspected moving in the longitudinal direction with a linear laser beam in the width direction, an area camera having a linear field of view of a predetermined width for photographing the irradiation position obliquely from above, and the area camera The unevenness information calculating means for calculating the unevenness information on the surface of the object to be inspected from the fluctuation of the reflection position of the linear laser beam photographed by the above, and the width of the average value for a plurality of pixels in the longitudinal direction with respect to the image of this area camera An uneven wrinkle inspection apparatus comprising: luminance image calculation means for calculating surface luminance image information by sequentially calculating in a direction.
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Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102853786A (en) * 2012-08-31 2013-01-02 深圳先进技术研究院 Apparatus and method for detecting flatness
KR101518592B1 (en) 2013-10-15 2015-05-15 주식회사 포스코 Apparatus and method of correcting surface image of scrfed slab
WO2016171265A1 (en) * 2015-04-22 2016-10-27 新日鐵住金株式会社 Shape-measuring device and method for measuring shape
JP2018048979A (en) * 2016-09-23 2018-03-29 新日鐵住金株式会社 Surface property inspection apparatus, surface property insection method, and program
CN108818544A (en) * 2018-06-05 2018-11-16 科芃智能科技（苏州）有限公司 The strip surfacing machine people of view-based access control model guiding
KR102011790B1 (en) * 2018-05-16 2019-08-19 라온피플 주식회사 Method and appratus for inspecting product using laser
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US10274314B2 (en) 2015-05-13 2019-04-30 Nippon Steel & Sumitomo Metal Corporation Shape inspection method, shape inspection apparatus, and program
KR101945662B1 (en) 2016-06-27 2019-02-07 신닛테츠스미킨 카부시키카이샤 Shape measuring device and shape measuring method

Citations (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS618610A (en) * 1984-06-22 1986-01-16 Sumitomo Metal Ind Ltd Apparatus for inspecting steel sheet surface
JPS62220803A (en) * 1986-03-20 1987-09-29 Toyota Central Res & Dev Lab Inc Three-dimensional coordinate measuring instrument
JPS62289752A (en) * 1986-06-10 1987-12-16 Toshiba Corp Surface inspecting device
JPS63132107A (en) * 1986-11-25 1988-06-04 Hitachi Ltd Light cutting line extracting circuit
JPS63274806A (en) * 1987-05-01 1988-11-11 Nippon Steel Corp Detection of shape of slip in continuous annealing furnace
JPS6476167A (en) * 1987-09-17 1989-03-22 Agency Ind Science Techn Linear light extracting circuit
JPH02187609A (en) * 1988-11-28 1990-07-23 Allegheny Internatl Inc System for generating surface image of metal work, measurement of ruggedness of surface thereof and apparatus for generating surface image of continuously cast slab
JPH03205503A (en) * 1990-01-08 1991-09-09 Mitsubishi Heavy Ind Ltd Image position detecting method for sheet light
JPH0438407A (en) * 1990-06-01 1992-02-07 Kawasaki Steel Corp Method for positioning video camera
JPH05196461A (en) * 1992-01-23 1993-08-06 Sumitomo Metal Ind Ltd Method of measuring distance with laser
JPH06148098A (en) * 1992-09-18 1994-05-27 Kawasaki Steel Corp Surface defect inspection apparatus
JPH07239221A (en) * 1993-05-24 1995-09-12 Komatsu Ltd Bending angle detector and linear extracting device and device for setting bending angle detection position therefor
JPH0843045A (en) * 1994-07-26 1996-02-16 Tokai Rika Co Ltd Three dimensional measuring apparatus
JPH09152322A (en) * 1995-11-30 1997-06-10 Nippon Steel Corp Method and device for surface quality inspection
JPH11142122A (en) * 1997-09-04 1999-05-28 Matsushita Electric Ind Co Ltd Range finder
JP2000292123A (en) * 1999-04-05 2000-10-20 Toshiba Corp Shape measuring apparatus
JP2001012918A (en) * 1999-07-01 2001-01-19 Nkk Corp Coil position-detecting device
JP2001255275A (en) * 2000-03-13 2001-09-21 Kawasaki Steel Corp Surface defect inspection method and device
JP2001296252A (en) * 2000-04-11 2001-10-26 Matsushita Electric Works Ltd Defect detection method of object surface, and device thereof
JP2002148196A (en) * 2000-11-15 2002-05-22 Nippon Steel Corp Shading correcting method
JP2005030812A (en) * 2003-07-08 2005-02-03 Nippon Steel Corp Method for inspecting surface of steel panel, inspection system, image processor, and computer program
JP2005134362A (en) * 2003-05-07 2005-05-26 Nippon Steel Corp Inspection method and inspection device for surface irregularity
JP2005189113A (en) * 2003-12-25 2005-07-14 Jfe Steel Kk Surface inspecting device and surface inspection method
JP2006177852A (en) * 2004-12-24 2006-07-06 Toshiba Corp Surface inspection device and its method
JP2007101359A (en) * 2005-10-04 2007-04-19 Nippon Steel Corp Flaw detector and flaw detection method
JP2007132858A (en) * 2005-11-11 2007-05-31 Nippon Steel Corp Flaw detection method, device and computer program
JP2008134148A (en) * 2006-11-28 2008-06-12 Kobe Steel Ltd Sectional shape measuring method and sectional shape measuring device
JP2008175625A (en) * 2007-01-17 2008-07-31 Konica Minolta Sensing Inc Three-dimensional measurement apparatus and portable gauge
JP2008203198A (en) * 2007-02-22 2008-09-04 Nippon Steel Corp Surface flaw inspecting system and flaw method, and computer program

Patent Citations (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS618610A (en) * 1984-06-22 1986-01-16 Sumitomo Metal Ind Ltd Apparatus for inspecting steel sheet surface
JPS62220803A (en) * 1986-03-20 1987-09-29 Toyota Central Res & Dev Lab Inc Three-dimensional coordinate measuring instrument
JPS62289752A (en) * 1986-06-10 1987-12-16 Toshiba Corp Surface inspecting device
JPS63132107A (en) * 1986-11-25 1988-06-04 Hitachi Ltd Light cutting line extracting circuit
JPS63274806A (en) * 1987-05-01 1988-11-11 Nippon Steel Corp Detection of shape of slip in continuous annealing furnace
JPS6476167A (en) * 1987-09-17 1989-03-22 Agency Ind Science Techn Linear light extracting circuit
JPH02187609A (en) * 1988-11-28 1990-07-23 Allegheny Internatl Inc System for generating surface image of metal work, measurement of ruggedness of surface thereof and apparatus for generating surface image of continuously cast slab
JPH03205503A (en) * 1990-01-08 1991-09-09 Mitsubishi Heavy Ind Ltd Image position detecting method for sheet light
JPH0438407A (en) * 1990-06-01 1992-02-07 Kawasaki Steel Corp Method for positioning video camera
JPH05196461A (en) * 1992-01-23 1993-08-06 Sumitomo Metal Ind Ltd Method of measuring distance with laser
JPH06148098A (en) * 1992-09-18 1994-05-27 Kawasaki Steel Corp Surface defect inspection apparatus
JPH07239221A (en) * 1993-05-24 1995-09-12 Komatsu Ltd Bending angle detector and linear extracting device and device for setting bending angle detection position therefor
JPH0843045A (en) * 1994-07-26 1996-02-16 Tokai Rika Co Ltd Three dimensional measuring apparatus
JPH09152322A (en) * 1995-11-30 1997-06-10 Nippon Steel Corp Method and device for surface quality inspection
JPH11142122A (en) * 1997-09-04 1999-05-28 Matsushita Electric Ind Co Ltd Range finder
JP2000292123A (en) * 1999-04-05 2000-10-20 Toshiba Corp Shape measuring apparatus
JP2001012918A (en) * 1999-07-01 2001-01-19 Nkk Corp Coil position-detecting device
JP2001255275A (en) * 2000-03-13 2001-09-21 Kawasaki Steel Corp Surface defect inspection method and device
JP2001296252A (en) * 2000-04-11 2001-10-26 Matsushita Electric Works Ltd Defect detection method of object surface, and device thereof
JP2002148196A (en) * 2000-11-15 2002-05-22 Nippon Steel Corp Shading correcting method
JP2005134362A (en) * 2003-05-07 2005-05-26 Nippon Steel Corp Inspection method and inspection device for surface irregularity
JP2005030812A (en) * 2003-07-08 2005-02-03 Nippon Steel Corp Method for inspecting surface of steel panel, inspection system, image processor, and computer program
JP2005189113A (en) * 2003-12-25 2005-07-14 Jfe Steel Kk Surface inspecting device and surface inspection method
JP2006177852A (en) * 2004-12-24 2006-07-06 Toshiba Corp Surface inspection device and its method
JP2007101359A (en) * 2005-10-04 2007-04-19 Nippon Steel Corp Flaw detector and flaw detection method
JP2007132858A (en) * 2005-11-11 2007-05-31 Nippon Steel Corp Flaw detection method, device and computer program
JP2008134148A (en) * 2006-11-28 2008-06-12 Kobe Steel Ltd Sectional shape measuring method and sectional shape measuring device
JP2008175625A (en) * 2007-01-17 2008-07-31 Konica Minolta Sensing Inc Three-dimensional measurement apparatus and portable gauge
JP2008203198A (en) * 2007-02-22 2008-09-04 Nippon Steel Corp Surface flaw inspecting system and flaw method, and computer program

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102853786A (en) * 2012-08-31 2013-01-02 深圳先进技术研究院 Apparatus and method for detecting flatness
KR101518592B1 (en) 2013-10-15 2015-05-15 주식회사 포스코 Apparatus and method of correcting surface image of scrfed slab
KR101968439B1 (en) * 2015-04-22 2019-04-11 신닛테츠스미킨 카부시키카이샤 Shape measuring device and shape measuring method
US10295335B2 (en) 2015-04-22 2019-05-21 Nippon Steel & Sumitomo Metal Corporation Shape measurement apparatus and shape measurement method
JPWO2016171265A1 (en) * 2015-04-22 2017-12-28 新日鐵住金株式会社 Shape measuring apparatus and shape measuring method
KR20170136619A (en) * 2015-04-22 2017-12-11 신닛테츠스미킨 카부시키카이샤 Shape measuring device and shape measuring method
EP3270101A4 (en) * 2015-04-22 2018-08-29 Nippon Steel & Sumitomo Metal Corporation Shape-measuring device and method for measuring shape
WO2016171265A1 (en) * 2015-04-22 2016-10-27 新日鐵住金株式会社 Shape-measuring device and method for measuring shape
JP2018048979A (en) * 2016-09-23 2018-03-29 新日鐵住金株式会社 Surface property inspection apparatus, surface property insection method, and program
KR102011790B1 (en) * 2018-05-16 2019-08-19 라온피플 주식회사 Method and appratus for inspecting product using laser
CN108818544A (en) * 2018-06-05 2018-11-16 科芃智能科技（苏州）有限公司 The strip surfacing machine people of view-based access control model guiding
CN108818544B (en) * 2018-06-05 2019-10-25 科芃智能科技（苏州）有限公司 The strip surfacing machine people of view-based access control model guiding
JP2020016667A (en) * 2019-10-25 2020-01-30 東急建設株式会社 Inspection device for deformed part
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