JPS63238540A - Steel plate flaw detection system using plural wavelengths - Google Patents
Steel plate flaw detection system using plural wavelengthsInfo
- Publication number
- JPS63238540A JPS63238540A JP7506487A JP7506487A JPS63238540A JP S63238540 A JPS63238540 A JP S63238540A JP 7506487 A JP7506487 A JP 7506487A JP 7506487 A JP7506487 A JP 7506487A JP S63238540 A JPS63238540 A JP S63238540A
- Authority
- JP
- Japan
- Prior art keywords
- steel plate
- flaw
- size
- electromagnetic waves
- wavelength
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 67
- 239000010959 steel Substances 0.000 title claims abstract description 67
- 238000001514 detection method Methods 0.000 title claims description 6
- 230000005540 biological transmission Effects 0.000 abstract description 4
- 239000002131 composite material Substances 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 9
- 238000007796 conventional method Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 239000002253 acid Substances 0.000 description 2
- 239000000428 dust Substances 0.000 description 2
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 1
- 238000012567 pattern recognition method Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/89—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles
- G01N21/8901—Optical details; Scanning details
Abstract
Description
【発明の詳細な説明】
〔概要〕
鋼板を長尺方向に移動させ、鋼板の表面上に鋼板の表面
上の幅方向の傷の大きさと同程度の波長を持つ電磁波を
複数種類投射しながら鋼板の幅方向に走査し、得られた
反射信号を受信・解析することにより鋼板表面上に在る
傷を検出する。[Detailed Description of the Invention] [Summary] A steel plate is moved in the longitudinal direction, and a plurality of types of electromagnetic waves having wavelengths comparable to the size of scratches in the width direction on the surface of the steel plate are projected onto the surface of the steel plate. The flaws on the steel plate surface are detected by scanning in the width direction of the steel plate and receiving and analyzing the resulting reflected signals.
本発明は鋼板の表面上に出来た傷を検出する方式に関す
るものである。The present invention relates to a method for detecting flaws formed on the surface of a steel plate.
鉄鋼会社の薄板工場等に於いては、鋼板等の長尺板状物
体の面上に在る傷を連続して而も高速度で検出すること
が必要である。In the thin plate factories of steel companies, it is necessary to detect flaws on the surface of long plate-shaped objects such as steel plates continuously and at high speed.
第４図は従来の鋼板の表面上の傷の検出方式の一例を示
す図である。FIG. 4 is a diagram showing an example of a conventional method for detecting flaws on the surface of a steel plate.
図中、■は鋼板、２はレーザ光源、３は回転ミラー、４
は受光器、５はＡ−Ｄ変換器、６はデータ処理装置であ
る。尚以下全図を通じ同一記号は同一対象物を表す。In the figure, ■ is a steel plate, 2 is a laser light source, 3 is a rotating mirror, and 4
5 is a photodetector, 5 is an A-D converter, and 6 is a data processing device. The same symbols represent the same objects throughout all the figures below.
鋼板１ （一般的には長尺板状物体）の表面上には傷が
在り、此の鋼板１は矢印の方向（Ｘ方向）に高速度で移
動している。There are scratches on the surface of the steel plate 1 (generally a long plate-shaped object), and this steel plate 1 is moving at high speed in the direction of the arrow (X direction).
一方レーザ光源２ （白色光源２が使用されることもあ
る）から出た光は回転ミラー３に投射され、反射されて
鋼板１の表面上の投射される。此の場合、鋼板１の表面
上に投射されるレーザ光のスポットは成る大きさを持っ
ている。On the other hand, light emitted from a laser light source 2 (a white light source 2 may be used) is projected onto a rotating mirror 3, reflected, and projected onto the surface of the steel plate 1. In this case, the spot of the laser beam projected onto the surface of the steel plate 1 has a size of .
回転ミラー３が回転するため、レーザ光のスポットは鋼
板１の幅方向（Ｙ方向）に成る速度で移動（走査）する
。Since the rotating mirror 3 rotates, the spot of the laser beam moves (scans) at a speed in the width direction (Y direction) of the steel plate 1.
此の様に成る大きさを持つレーザ光のスポットが鋼板１
の表面上をＹ方向に走査し、得られる反射光を受光器４
で受光して電気信号に変換した後、Ａ−Ｄ変換器５によ
りディジタル化されてデータ処理装置６に入力されて解
析される。A spot of laser light with a size like this is on steel plate 1.
is scanned in the Y direction on the surface of the
After receiving the light and converting it into an electrical signal, it is digitized by an A-D converter 5 and input to a data processing device 6 for analysis.
此れはレーザ光が鋼板１の表面上に在る傷に投射した時
と、傷のない表面に投射した時とでは反射光の大きさに
変化があるのを利用して傷の検出を行う方式である。This detects flaws by utilizing the difference in the size of the reflected light when the laser beam is projected onto a flaw on the surface of the steel plate 1 and when it is projected onto a surface without flaws. It is a method.
然しなから鋼板１が移動する速度は例えば１８０ｍ／分
で大変速く、而もレーザスポットの大きさは数ｍｍ平方
であるので、すり傷、小さい傷等の場合には検出が難し
いと云う問題点があった。However, the speed at which the steel plate 1 moves is very fast, for example 180 m/min, and the size of the laser spot is several mm square, so there is a problem that it is difficult to detect scratches, small scratches, etc. was there.
又同じ反射光量の傷であっても、成るものは重大な傷で
あり、又成るものは無視しても良い傷であることがあり
、傷の種類も又重要であるので、データ処理装置６によ
りパターン認識の手法を採用して対応しているが、正確
に判別出来ないと云う問題点があった。In addition, even if the amount of reflected light is the same, some scratches may be serious and others may be ignored, and the type of scratch is also important, so the data processing device 6 Although a pattern recognition method has been adopted to deal with this problem, there is a problem in that accurate discrimination cannot be performed.
上記問題点は第１図の原理図に示す様に、鋼板工を長尺
方向に移動させる手段５０．鋼板１０表面上に鋼板１の
幅方向の傷の大きさと同程度の波長を持つ電磁波を複数
種類投射する手段６０、鋼板１０表面上に投射した前記
複数種類の電磁波を鋼板１の幅方向に走査する手段７０
、及び投射手段６０と走査手段７０により得られた反射
信号を受信する手段８０を設けることにより解決される
。The above problem is solved by the means 50 for moving the steel plate work in the longitudinal direction, as shown in the principle diagram of FIG. means 60 for projecting a plurality of types of electromagnetic waves having wavelengths comparable to the size of scratches in the width direction of the steel plate 1 onto the surface of the steel plate 10; scanning the plurality of types of electromagnetic waves projected onto the surface of the steel plate 10 in the width direction of the steel plate 1; means 70
, and means 80 for receiving the reflected signals obtained by the projection means 60 and the scanning means 70.
本発明に依ると、移動手段５０により鋼板１を長尺方向
に移動させ、投射手段６０により鋼板１の幅方向の傷の
大きさと同程度の波長を持つ複数種類の電磁波を鋼板１
の表面上に投射し、走査手段７０により鋼板１の表面上
に投射されている複数種類の電磁波を鋼板１の幅方向に
走査し、受信手段８０により鋼板１からの反射信号を受
信し、受信した反射信号に基づき鋼板１の表面上に在る
傷の程度、種別を検出することが可能となる。According to the present invention, the moving means 50 moves the steel plate 1 in the longitudinal direction, and the projecting means 60 applies a plurality of types of electromagnetic waves having wavelengths comparable to the size of the flaw in the width direction of the steel plate 1 to the steel plate 1.
The scanning means 70 scans the multiple types of electromagnetic waves projected onto the surface of the steel plate 1 in the width direction of the steel plate 1, and the receiving means 80 receives the reflected signal from the steel plate 1. It becomes possible to detect the degree and type of flaws present on the surface of the steel plate 1 based on the reflected signals.
第２図は本発明に依る複数波長による鋼板傷検出方式の
一実施例を示す図である。FIG. 2 is a diagram showing an embodiment of a steel plate flaw detection method using multiple wavelengths according to the present invention.
第３図は本発明の説明図である。FIG. 3 is an explanatory diagram of the present invention.
図中、１０は発信源、２０ａ、２０ｂ、及び２０ｃは夫
々分波器、３０ａ、３０ｂ、及び３０ｃは夫々受信器、
４０はＡ−Ｄ変換器である。In the figure, 10 is a source, 20a, 20b, and 20c are demultiplexers, and 30a, 30b, and 30c are receivers, respectively.
40 is an AD converter.
従来鋼板１上に生ずる傷で検出の対象となるものは鋼板
１の幅方向の大きさが通常０．１ｍｍ以上のものである
。Conventionally, flaws that occur on the steel plate 1 and are subject to detection are those whose size in the width direction of the steel plate 1 is usually 0.1 mm or more.
然しなから従来方式では上記傷の大きさより海かに短い
波長を有する白色光又はレーザ光を鋼板１上に投射して
其の反射光を受光していた。However, in the conventional method, white light or laser light having a wavelength much shorter than the size of the scratch is projected onto the steel plate 1, and the reflected light is received.
本発明では波長が鋼板１上に生ずる傷の大きさく鋼板ｌ
の幅方向の大きさ）と略同等の波長を持つ電磁波を使用
する。In the present invention, the wavelength varies depending on the size of the scratches on the steel plate 1.
An electromagnetic wave with a wavelength approximately equal to the width direction of the
例えば、第３図（ａｌは鋼板１のすり傷Ａの幅の大きさ
より長い波長へを持つ電磁波が鋼板１の表面上に投射さ
れた場合を示す。此の場合にはすり傷Ａ、すり傷Ａより
少し大きい傷Ｂでは乱反射はなく、乱反射が行われるの
は鋼板１の表面上に大きな傷Ｃがあった場合である。尚
図中の正、乱は夫々正反射、乱反射を示す。For example, Fig. 3 (al) shows the case where electromagnetic waves having a wavelength longer than the width of the scratch A on the steel plate 1 are projected onto the surface of the steel plate 1. There is no diffuse reflection in a flaw B that is slightly larger than A, and diffuse reflection occurs when there is a large flaw C on the surface of the steel plate 1. Note that normal and diffuse in the figure indicate regular reflection and diffuse reflection, respectively.
第３図（ｂｌは鋼板１のすり傷の幅の大きさより長いが
、其の他の太い傷の幅より短い波長λ、を持つ電磁波が
鋼板１の表面上に投射された場合を示す。此の場合には
すり傷へでは乱反射はなく、乱反射が行われるのは鋼板
ｌの表面上に大きな傷Ｃ１及びすり傷へより少し大きい
傷Ｂがあった場合である。Figure 3 (bl shows the case where an electromagnetic wave having a wavelength λ longer than the width of a scratch on the steel plate 1 but shorter than the width of other thick scratches is projected onto the surface of the steel plate 1. In the case of , there is no diffused reflection from the scratches, and diffused reflection occurs when there is a large scratch C1 on the surface of the steel plate 1 and a slightly larger scratch B than the scratch.
第３図（Ｃ）は鋼板１のすり傷の幅Ａの大きさより短い
波長λ。を持つ電磁波が細板１の表面上に投射された場
合を示す。此の場合にはすり傷Ａ、すり傷Ａより大きい
傷Ｂ、更に大きな傷Ｃでも乱反射が起こる。FIG. 3(C) shows a wavelength λ shorter than the width A of the scratch on the steel plate 1. The case is shown in which an electromagnetic wave with . In this case, the scratch A, the scratch B larger than the scratch A, and the even larger scratch C cause diffused reflection.
尚第３図（ｄ）は鋼板１の表面上の傷を示す図である。Incidentally, FIG. 3(d) is a diagram showing flaws on the surface of the steel plate 1.
此の様に投射する電磁波の波長と、傷の大きさにより、
正反射したり、乱反射したりする。更に正反射、又は乱
反射の程度が変化する。Depending on the wavelength of the electromagnetic waves projected like this and the size of the scratch,
Reflects specularly or diffusely. Furthermore, the degree of specular reflection or diffused reflection changes.
従って本発明に於いては従来の白色光又はレーザ光の光
源２の代わりに発信源１０を使用する。Therefore, in the present invention, a source 10 is used in place of the conventional white light or laser light source 2.
本発明の発信源１０は例えば、■鋼板１上に生ずる傷の
大きさく鋼板１の幅方向）と略同等の波長λ５を持つ電
磁波、■波長λ５より短い波長λ３を持つ電磁波、及び
■波長λ５より長い波長λ。The transmitting source 10 of the present invention can emit, for example, (1) an electromagnetic wave having a wavelength λ5 that is approximately equal to the size of a flaw occurring on the steel plate 1 (in the width direction of the steel plate 1), (2) an electromagnetic wave having a wavelength λ3 shorter than the wavelength λ5, and (2) an electromagnetic wave having a wavelength λ5. longer wavelength λ.
を持つ電磁波を、夫々発信する発信源の複合発信源であ
る。It is a composite source of sources that each emit electromagnetic waves with a certain characteristic.
本発明の発信源１０から複数個の波長（此の場合には、
λ３、λ１、及びλＣ）の電磁波が鋼板１の表面上に投
射されると、波長により夫々正反射、乱反射の状態が異
なる。A plurality of wavelengths (in this case,
When electromagnetic waves of wavelengths λ3, λ1, and λC are projected onto the surface of the steel plate 1, the states of regular reflection and diffuse reflection differ depending on the wavelength.
第２図に示す様に得られる反射電磁波の中から分波ｔｇ
２０ａにより波長λ、酸成分分離して受信器３０ａによ
り受信し、分波器２０ｂにより波長λ、酸成分分離して
受信器３０ｂにより受信し、分波器２０Ｃにより波長λ
。成分を分離して受信器３０ｃにより受信する。As shown in Figure 2, the resulting reflected electromagnetic waves are divided into tg
20a separates the wavelength λ and the acid component and receives it at the receiver 30a, the demultiplexer 20b separates the wavelength λ and the acid component and receives it at the receiver 30b, and the demultiplexer 20C separates the wavelength λ.
. The components are separated and received by receiver 30c.
此れ等各受信器３０ａ、３０ｂ、及び３０ｃの出力をＡ
＝Ｄ変換器４０によりディジタル化し、データ処理装置
６で解析することにより、傷の程度、種類を識別出来る
。The outputs of these receivers 30a, 30b, and 30c are A
By digitizing the data using the =D converter 40 and analyzing it using the data processing device 6, the degree and type of damage can be identified.
向上記説明に於いては３種類の波長の電磁波を使用した
が、必ずしも此の必要はなく、例えば２種類の電磁波を
使用して識別を行うことも可能である。Although electromagnetic waves of three types of wavelengths are used in the above description, this is not necessarily necessary, and it is also possible to perform identification using, for example, two types of electromagnetic waves.
又受信した電磁波を分波器により分離したが、必ずしも
此の必要はなく正反射用の受信器、乱反射用の受信器を
配置する方法も考えられる。Furthermore, although the received electromagnetic waves are separated by a splitter, this is not necessarily necessary, and a method of arranging a receiver for specular reflection and a receiver for diffuse reflection may also be considered.
更に発信源１０から同時に複数種類の電磁波を発信した
が、発信場所を変えて同時に複数種類の電磁波を発信す
ることも可能であり、又時分割的に発信することも可能
である。Furthermore, although a plurality of types of electromagnetic waves are simultaneously transmitted from the transmission source 10, it is also possible to transmit a plurality of types of electromagnetic waves at the same time by changing the transmission location, or it is also possible to transmit them in a time-sharing manner.
複数種類の電磁波を混合して投射しても、時分割的に投
射しても同様な効果が得られる。The same effect can be obtained even if multiple types of electromagnetic waves are mixed and projected or time-divisionally projected.
尚従来の白色光又はレーザ光では光源２の表面上に付着
した埃に弱かったが、普通埃の大きさはすり傷より小さ
いので影響を受けることはない。It should be noted that conventional white light or laser light is sensitive to dust attached to the surface of the light source 2, but since the size of dust is usually smaller than a scratch, it is not affected.
以上詳細に説明した様に本発明によれば、各種波長の電
磁波を投射することにより傷の程度、種類を識別出来る
と云う大きい効果がある。As described above in detail, the present invention has the great effect of being able to identify the extent and type of scratches by projecting electromagnetic waves of various wavelengths.
第１図は本発明の原理図である。
第２図は本発明に依る複数波長による鋼板傷検出方式の
一実施例を示す図である。
第３図は本発明の説明図である。
第４図は従来の鋼板の表面上の傷の検出方式の一例を示
す図である。
図中、■は鋼板、２はレーザ光源、３は回転ミラー、４
は受光器、５はＡ−Ｄ変換器、６はデータ処理装置、１
０は発信源、２０ａ、２０ｂ、及び２０ｃは夫々分波器
、３０ａ、３０ｂ、及び３０Ｃは夫々受信器、４０はＡ
−Ｄ変換器、５０は移動手段、６０は投射手段、７０は
走査手段、８０は受信手段である。
第２ ｍ
本手ら日月のも地日月図
′広 ネ Ｍ
７鉋粟の槍印版の友面上のＸ鵬の検出方式の−・イク・
］乞示す図洸４目FIG. 1 is a diagram showing the principle of the present invention. FIG. 2 is a diagram showing an embodiment of a steel plate flaw detection method using multiple wavelengths according to the present invention. FIG. 3 is an explanatory diagram of the present invention. FIG. 4 is a diagram showing an example of a conventional method for detecting flaws on the surface of a steel plate. In the figure, ■ is a steel plate, 2 is a laser light source, 3 is a rotating mirror, and 4
is a photoreceiver, 5 is an A-D converter, 6 is a data processing device, 1
0 is a source, 20a, 20b, and 20c are demultiplexers, 30a, 30b, and 30C are receivers, and 40 is an A
-D converter, 50 is a moving means, 60 is a projection means, 70 is a scanning means, and 80 is a receiving means. 2nd M Main hand Sun and Moon map 'Hiro Ne M 7 The detection method of
] Begging illustration 4th item
Claims (1)
板（１）の表面上に該鋼板（１）の幅方向の傷の大きさ
と同程度の波長を持つ電磁波を複数種類投射する手段（
６０）、 該鋼板（１）の表面上に投射した該複数種類の該電磁波
を該鋼板（１）の幅方向に走査する手段（７０）、及び
該投射手段（６０）と該走査手段（７０）により得られ
た反射信号を受信する手段（８０）を設け、該受信手段
（８０）により得られた該反射信号に基づき、該鋼板（
１）の表面上に在る傷を検出することを特徴とする複数
波長による鋼板傷検出方式。[Claims] A means (50) for moving the steel plate (1) in the longitudinal direction, a means (50) having a wavelength on the surface of the steel plate (1) comparable in size to the size of the flaw in the width direction of the steel plate (1). A means of projecting multiple types of electromagnetic waves (
60), means (70) for scanning the plurality of types of electromagnetic waves projected onto the surface of the steel plate (1) in the width direction of the steel plate (1), and the projection means (60) and the scanning means (70); ) is provided, and based on the reflected signal obtained by the receiving means (80), the steel plate (
1) A steel plate flaw detection method using multiple wavelengths, which is characterized by detecting flaws on the surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7506487A JPS63238540A (en) | 1987-03-27 | 1987-03-27 | Steel plate flaw detection system using plural wavelengths |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7506487A JPS63238540A (en) | 1987-03-27 | 1987-03-27 | Steel plate flaw detection system using plural wavelengths |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63238540A true JPS63238540A (en) | 1988-10-04 |
Family
ID=13565400
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7506487A Pending JPS63238540A (en) | 1987-03-27 | 1987-03-27 | Steel plate flaw detection system using plural wavelengths |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63238540A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04128637A (en) * | 1990-09-19 | 1992-04-30 | Kawasaki Steel Corp | Inspecting method for surface defect |
| JPH04128636A (en) * | 1990-09-19 | 1992-04-30 | Kawasaki Steel Corp | Inspecting method for surface defect |
-
1987
- 1987-03-27 JP JP7506487A patent/JPS63238540A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04128637A (en) * | 1990-09-19 | 1992-04-30 | Kawasaki Steel Corp | Inspecting method for surface defect |
| JPH04128636A (en) * | 1990-09-19 | 1992-04-30 | Kawasaki Steel Corp | Inspecting method for surface defect |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1049925B1 (en) | Optical inspection method and apparatus | |
| EP2237136A1 (en) | Optical detection apparatus and method | |
| CN102778460A (en) | Method for detecting internal flaw of substrate | |
| CA2198283A1 (en) | Three dimensional color imaging | |
| JPS6089735A (en) | Detector for defect of flat article | |
| EP0903559A3 (en) | Information recording apparatus using an interference device for position detection and positioning | |
| US5061063A (en) | Methods and apparatus for optical product inspection | |
| JPS63238540A (en) | Steel plate flaw detection system using plural wavelengths | |
| EP0119355B1 (en) | Position detecting apparatus | |
| JPS6234097B2 (en) | ||
| EP0244092B1 (en) | Optical apparatus and method for examining an object | |
| GB2117897A (en) | Detecting surface defects | |
| US3958128A (en) | System for determining a transversal position of any defect in a traveling sheet material | |
| US4622502A (en) | Position detecting apparatus | |
| EP0528915B1 (en) | Method and apparatus for determining the image clarity of a surface | |
| US6934029B1 (en) | Dual laser web defect scanner | |
| Young | Use of linescan cameras and a DSP processing system for high-speed wood inspection | |
| JPH01113639A (en) | Visual inspection apparatus | |
| JPH0228815B2 (en) | ||
| JPH05149809A (en) | Optical type tactile sensor | |
| JPH04215045A (en) | Laser inspecting device | |
| JPH039205A (en) | Position sensitive photodetector | |
| JPS592488Y2 (en) | Shape determination device | |
| JPH0814547B2 (en) | Surface inspection device | |
| JPH0786477B2 (en) | Surface inspection device |