JP2839934B2 - Inspection method for defects on the inner wall of the cylinder - Google Patents
Inspection method for defects on the inner wall of the cylinderInfo
- Publication number
- JP2839934B2 JP2839934B2 JP2143345A JP14334590A JP2839934B2 JP 2839934 B2 JP2839934 B2 JP 2839934B2 JP 2143345 A JP2143345 A JP 2143345A JP 14334590 A JP14334590 A JP 14334590A JP 2839934 B2 JP2839934 B2 JP 2839934B2
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- Prior art keywords
- image
- wall surface
- scope
- imaging camera
- inspection
- Prior art date
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- Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
- Closed-Circuit Television Systems (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、撮像機器と画像処理装置とを用いて、各
種ワークの円筒内壁面の欠陥を自動的に検査する検査方
法に関するものである。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection method for automatically inspecting a cylindrical inner wall surface of various works for defects using an imaging device and an image processing device.
シリンダブロックのボアの如き円筒内壁面の欠陥検査
は、作業者の目視による検査が一般に行われている。し
かし、目視による検査は熟練が必要で、判定も難しいた
め、機械による自動化が望まれていた。Inspection of defects on the inner wall surface of a cylinder such as a bore of a cylinder block is generally performed by visual inspection of an operator. However, since visual inspection requires skill and determination is difficult, automation by a machine has been desired.
上記検査を自動化する手段としては、ワークの円筒内
壁面を撮像機器にて撮像し、これより得られた画像を画
像処理して検査する手段がある。As means for automating the above-mentioned inspection, there is a means for taking an image of the inner wall surface of a cylinder of a work with an imaging device and performing image processing on an image obtained from the image to inspect the image.
これは、例えば第11図に示す様に、撮像カメラ(1)
の下面にスコープ(2)を取付け、スコープ(2)の下
方に平板ミラー(3)を45゜傾けて回転自在に設置した
撮像機器を昇降自在に設置し、撮像カメラ(1)から画
像信号を画像処理装置(4)へ出力するように構成され
ている。またスコープ(2)にはワーク(5)の円筒内
壁面(6)を照らす照射手段(図示せず)が付設されて
いる。This is, for example, as shown in FIG.
A scope (2) is attached to the lower surface of the camera, and a flat mirror (3) is tilted at an angle of 45.degree. Below the scope (2). It is configured to output to the image processing device (4). The scope (2) is provided with irradiation means (not shown) for illuminating the cylindrical inner wall surface (6) of the work (5).
この検査手段は、平板ミラー(3)及びスコープ
(2)をワーク(5)の円筒内壁面(6)内へ挿入し、
円筒内壁面(6)を照らす。すると円筒内壁面(6)の
一部の画像が平板ミラー(3)にて90゜方向に反射さ
れ、スコープ(2)を通して撮像カメラ(1)にて撮像
され、その画像信号が画像処理装置(4)へ出力され
る。そして画像処理装置(4)では入力された画像信号
を基に所定の画像処理を行い、欠陥の有無を判定する。This inspection means inserts a flat mirror (3) and a scope (2) into a cylindrical inner wall surface (6) of a work (5),
Illuminate the inner wall of the cylinder (6). Then, an image of a part of the inner wall surface (6) of the cylinder is reflected in the 90 ° direction by the flat mirror (3), captured by the imaging camera (1) through the scope (2), and its image signal is processed by the image processing device ( Output to 4). Then, the image processing device (4) performs predetermined image processing based on the input image signal, and determines the presence or absence of a defect.
上記作業は、撮像機器を上下方向に移動させ、かつ平
板ミラー(3)を回転させて、円筒内壁面(6)の全面
について行う。The above operation is performed on the entire surface of the cylindrical inner wall surface (6) by moving the imaging device in the vertical direction and rotating the flat mirror (3).
上記手段であれば、撮像カメラ(1)全体に円筒内壁
面(6)が撮像されているときは、入力画像における検
査領域が一定であるので、検査が容易である。According to the above means, when the cylindrical inner wall surface (6) is imaged over the entire imaging camera (1), the inspection area in the input image is constant, so that the inspection is easy.
しかし、円筒内壁面(6)の上下端近傍では、円筒内
壁面以外の背景部分も同時に撮像カメラ(1)に撮像さ
れ、その入力画像(7)は第12図に示す様に背景部分
(8)が暗くなる。そのため、正確な判定をするために
背景部分(8)を除くように検査領域を設定せねばなら
ない。この場合、平板ミラー(3)の回転位置によって
第13図に示す様に背景部分(7)の配置が刻々と変わっ
てしまう。そのため、各入力画像毎に検査領域を設定せ
ねばならず、検査に多くの時間がかかってしまう。However, near the upper and lower ends of the cylindrical inner wall surface (6), a background portion other than the cylindrical inner wall surface is also imaged by the imaging camera (1) at the same time, and the input image (7) is input to the background portion (8) as shown in FIG. ) Becomes darker. Therefore, in order to make an accurate determination, the inspection area must be set so as to remove the background portion (8). In this case, the arrangement of the background portion (7) changes every moment as shown in FIG. 13 depending on the rotational position of the flat mirror (3). Therefore, an inspection area must be set for each input image, and the inspection takes a lot of time.
上記問題点を解決するためには、撮像カメラ(1)を
平板ミラー(3)と一緒に回転させればよい。しかし、
撮像カメラ(1)を回転させるためには、断線等の問題
を処理せねばならない。In order to solve the above problem, the imaging camera (1) may be rotated together with the flat mirror (3). But,
In order to rotate the imaging camera (1), problems such as disconnection must be dealt with.
また、断線を生じないようにしたものとして、例えば
特開平1−97809号公報にて開示されたものがある。し
かし、回転部の構造が複雑であり、円筒内壁面(6)を
全周検査するには上記と同様に時間がかかる。Further, as a device for preventing disconnection, there is, for example, a device disclosed in JP-A-1-97809. However, the structure of the rotating part is complicated, and it takes time to inspect the inner wall surface (6) of the cylinder all around as described above.
この発明は、撮像カメラや平板ミラー等を回転させる
ことなく円筒内壁面を検査できるようにした検査方法を
提供しようとするものである。An object of the present invention is to provide an inspection method capable of inspecting an inner wall surface of a cylinder without rotating an imaging camera, a flat mirror, and the like.
この発明における検査方法は昇降可能に支持した撮像
カメラと、前記撮像カメラの下方に垂設した小径の探査
用スコープと、前記スコープの下方に同芯状に設置した
円錐形状のコーンミラーと、前記撮像カメラにて撮像さ
れた画像を画像処理する画像処理装置とを備え、前記ス
コープの下方及びコーンミラーを円筒内壁面内にその中
心軸に沿って挿入して円筒内壁面の周面を撮像し、前記
画像処理装置において、前記撮像カメラからの入力画像
に対して水平方向及び垂直方向のヒストグラムをとって
その画像中心を求め、この中心を基準としてドーナツ状
に検査領域を設定し、かつ、前記画像中心を中心とする
等幅同芯リング状の複数の判定領域を設定し、各判定領
域毎に画像円周方向の収縮歪に対応させて欠陥面積の判
定基準値を設定し、前記検査領域から微分処理及び2値
化処理で得られた欠陥面積値と前記判定基準値とを比較
演算し、前記判定基準値よりも大きな欠陥面積値がある
か否かによって欠陥の有無を判定するようにしたもので
ある。The inspection method according to the present invention includes an imaging camera supported so as to be able to move up and down, a small-diameter exploration scope vertically provided below the imaging camera, a conical cone mirror installed concentrically below the scope, An image processing device that performs image processing on an image captured by an imaging camera, and inserts a cone mirror below the scope and inside the cylindrical inner wall surface along the central axis to image the peripheral surface of the cylindrical inner wall surface. In the image processing apparatus, horizontal and vertical histograms are obtained for an input image from the imaging camera to determine the center of the image, and an inspection area is set in a donut shape based on the center, and A plurality of equal-width concentric ring-shaped determination areas centered on the image center are set, and a determination reference value of the defect area is set for each determination area in correspondence with the shrinkage strain in the image circumferential direction, A defect area value obtained by differentiating and binarizing processing from the inspection area is compared with the determination reference value, and the presence or absence of a defect is determined based on whether there is a defect area value larger than the determination reference value. It is something to do.
上記検査方法では、スコープやコーンミラーを回転さ
せることなく、円筒内壁面の周面を一定高さ毎に撮像し
て欠陥検査でき、作業時間を短縮できる。また円筒内壁
面の上下端において撮像カメラからの入力画像内に円筒
内壁面以外の背景部分が入っていても、該背景部分を検
査領域から除外でき、円筒内壁面の上下端も正確に欠陥
の有無を判定できる。According to the above inspection method, the peripheral surface of the inner wall surface of the cylinder can be imaged at regular intervals without rotating the scope or the cone mirror, and the defect can be inspected, so that the operation time can be reduced. Also, even if a background portion other than the cylindrical inner wall surface is included in the input image from the imaging camera at the upper and lower ends of the cylindrical inner wall surface, the background portion can be excluded from the inspection area, and the upper and lower ends of the cylindrical inner wall surface can be accurately detected as defects. Presence or absence can be determined.
以下、この発明の実施例を第1図乃至第10図を参照し
て説明する。An embodiment of the present invention will be described below with reference to FIGS. 1 to 10.
円筒内壁面(16)を撮像し、検査する検査装置は、撮
像カメラ(10)の下部に垂設したスコープ(11)と、ス
コープ(11)の下方に同芯上に配置した円錐形のコーン
ミラー(12)と、スコープ(11)を通して円筒内壁面
(16)を照らす照明装置(13)と、撮像カメラ(10)に
て撮像された画像を画像処理して欠陥の有無を判定する
画像処理装置(14)と、画像を写し出すモニターテレビ
(15)とから成っている。The inspection device that images and inspects the inner wall surface of the cylinder (16) consists of a scope (11) vertically suspended below the imaging camera (10) and a conical cone placed concentrically below the scope (11). A mirror (12), an illuminating device (13) for illuminating the inner wall surface (16) of the cylinder through a scope (11), and image processing for determining the presence or absence of a defect by performing image processing on an image captured by an imaging camera (10). It consists of a device (14) and a monitor television (15) for displaying images.
上記スコープ(11)は検査対象となる円筒内壁面(1
6)より小径でかつ深い長さのものが使用され、内部に
はレンズ(17)を取付けてある。またコーンミラー(1
2)も円筒内壁面(16)より小径のものが使用され、ス
コープ(11)の下方に同芯上に配置され、透明なガラス
筒(18)にて支持される。The scope (11) is the inner wall of the cylinder (1
6) A smaller diameter and deeper one is used, with a lens (17) mounted inside. Also a cone mirror (1
2) also has a smaller diameter than the cylindrical inner wall surface (16), is arranged concentrically below the scope (11), and is supported by a transparent glass tube (18).
照明装置(13)は別設した光源(19)の光を光ファイ
バ(20)にてスコープ(11)の先端まで導き、スコープ
(11)の先端から円筒内壁面(16)を照らす。The illuminating device (13) guides the light of the separately provided light source (19) to the tip of the scope (11) via the optical fiber (20), and illuminates the cylindrical inner wall surface (16) from the tip of the scope (11).
上記検査装置は、撮像カメラ(10)を昇降可能に支持
し、検査時前記コーンミラー(12)及びスコープ(11)
を円筒内壁面(16)の中心軸に沿って移動させ、かつコ
ーンミラー(12)の反射面(12a)が円筒内壁面(16)
の上下端縁と夫々交差する範囲で撮像カメラ(10)を昇
降させる。The inspection device supports the imaging camera (10) so as to be able to move up and down, and at the time of inspection, the cone mirror (12) and the scope (11)
Is moved along the center axis of the cylindrical inner wall surface (16), and the reflecting surface (12a) of the cone mirror (12) is moved to the cylindrical inner wall surface (16).
The imaging camera (10) is moved up and down in a range that intersects the upper and lower edges, respectively.
画像処理装置(14)は撮像カメラ(10)から送られて
くる入力画像に対して後述の如き画像処理を行って欠陥
の有無を判定する。The image processing device (14) performs image processing as described below on the input image sent from the imaging camera (10) to determine the presence or absence of a defect.
即ち、コーンミラー(12)にて反射され、スコープ
(11)を通して撮像カメラ(10)にて撮像された円筒内
壁面(16)は第2図に示す示す様に円形状の画像とな
り、中心部に近づく程周方向が縮小されている。従って
円筒内壁面(16)に円形の欠陥があれば中心部に向かっ
て長くなった楕円の画像となり、正方形の欠陥であれ
ば、中心部側が狭い扇形の画像となる。尚、実際の検査
時は、スコープ(11)とコーンミラー(12)との配置関
係から有効な視野幅から入る像はドーナツ状となって
り、このドーナツ状の画像(21)は他よりも明るく写し
出される。また欠陥は黒く写し出される。That is, the cylindrical inner wall surface (16) reflected by the cone mirror (12) and imaged by the imaging camera (10) through the scope (11) becomes a circular image as shown in FIG. , The circumferential direction is reduced. Therefore, if there is a circular defect on the inner wall surface (16) of the cylinder, the image becomes an elliptical image elongated toward the center, and if it is a square defect, the image becomes a fan-shaped image with a narrower central portion. At the time of the actual inspection, the image entering from the effective visual field width has a donut shape due to the positional relationship between the scope (11) and the cone mirror (12), and the donut-shaped image (21) is more than the others. It is projected brightly. In addition, the defect is displayed in black.
そして、画像処理装置(14)に撮像カメラ(10)から
上記画像が入力されると、その入力画像のデータをフレ
ームメモリに入力し、そのデータに基づいて以後の処理
を行う。先ず第3図に示す様に入力画像に対して垂直射
影ヒストグラム(22)と水平射影ヒストグラム(23)を
とり、垂直射影ヒストグラム(22)において、両端の座
標(X1)(X2)からその中心 を求め、同時に水平射影ヒストグラム(23)において、
両端の座標(Y1)(Y2)からその中心 を求め、画像中心 を算出する。この後第4図に示す様に画像中心 を通る線上での濃度断面図を描き、これによりドーナツ
状の画像(21)の内側の座標(X3)(X4)を求める。そ
して第5図に示す様に、今までに得られた画像中心 と座標(X1)(X2)(X3)(X4)から、画像中心 に対し座標(X1)(X2)(X3)(X4)を通るドーナツ状
の検査領域(24)を設定する。検査領域(24)が設定さ
れると、該検査領域(24)を一定の幅(l)でリング状
に細分化し、第6図に示す様な複数の判定領域(L1)〜
(Ln)を設定する。この判定領域(L1)〜(Ln)の幅
(l)は不良と判定すべき欠陥径の直径と同じ長さに設
定する。例えば最小の欠陥の直径が0.5mmであれば、幅
(l)も0.5mmに設定する。設定後、検査領域(24)内
の入力画像に対して縦横方向の微分を行い、さらに2値
化処理を行う。2値化後判定領域(L1)〜(Ln)内での
欠陥の面積値(S1)〜(Sn)は各判定領域(L1)〜(L
n)内での暗い画素数をカウントすることにより求め
る。一方隣合う2つの判定領域(L1とL2)、(L2と
L3)、(L3とL4)…(Ln-1とLn)内における基準判定値
(y1)(y2)…(ym)(m=n-1)を設定しておく。こ
の基準判定値(y1)(y2)…(ym)は夫々所定の判定
領域内において不良と判定すべき最小の欠陥径内の画素
数の割合であり、2値化された画像に対する回帰直線を
基に算出する。そして第7図に示す様に前記欠陥の面積
値(S1)〜(Sn)と基準判定値(y1)〜(ym)とを基
に(S1+S2)と(y1)、(S2+S3)と(y2)、(S3+
S4)と(y3)、…(Sn-1+Sm)と(ym)との比較演算
を行い、基準判定値(y1)〜(ym)より大きい面積値
が1つでもあると製品を不良とする。When the image is input from the imaging camera (10) to the image processing device (14), the data of the input image is input to the frame memory, and the subsequent processing is performed based on the data. First, as shown in FIG. 3, a vertical projection histogram (22) and a horizontal projection histogram (23) are taken for an input image, and the coordinates (X 1 ) and (X 2 ) at both ends are obtained from the vertical projection histogram (22). center And at the same time, in the horizontal projection histogram (23),
From the coordinates (Y 1 ) (Y 2 ) of both ends to its center Find the image center Is calculated. Thereafter, as shown in FIG. A concentration cross-sectional view is drawn on a line passing through to obtain coordinates (X 3 ) and (X 4 ) inside the donut-shaped image (21). Then, as shown in FIG. 5, the center of the image obtained so far From the coordinates (X 1 ) (X 2 ) (X 3 ) (X 4 ), the image center To set the coordinates (X 1) (X 2) (X 3) donut-shaped inspection area through the (X 4) (24). When the inspection region (24) is set, and divided into ring the examination region (24) at a constant width (l), Figure 6 to show such a plurality of determination areas (L 1) ~
(Ln). The width (l) of each of the determination areas (L 1 ) to (Ln) is set to the same length as the diameter of the defect to be determined to be defective. For example, if the minimum defect diameter is 0.5 mm, the width (l) is also set to 0.5 mm. After the setting, the input image in the inspection area (24) is differentiated in the vertical and horizontal directions, and further subjected to a binarization process. The area values (S 1 ) to (Sn) of the defects in the binarized judgment regions (L 1 ) to (Ln) are the respective judgment regions (L 1 ) to (L
It is obtained by counting the number of dark pixels in n). On the other hand, two adjacent determination areas (L 1 and L 2 ), (L 2 and
L 3), setting the (L 3 and L 4) ... (Ln -1 and Ln) a reference judgment value within (y 1) (y 2) ... (ym) (m = n -1). The reference determination values (y 1 ) (y 2 )... (Ym) are the ratios of the number of pixels within the minimum defect diameter to be determined to be defective within a predetermined determination area, and are used for regression of the binarized image. Calculate based on the straight line. Then, as shown in FIG. 7, based on the area values (S 1 ) to (Sn) of the defect and the reference judgment values (y 1 ) to (ym), (S 1 + S 2 ), (y 1 ), (y 1 ) S 2 + S 3 ), (y 2 ), (S 3 +
S 4) and (y 3), ... (Sn perform -1 + Sm) and the comparison operation between (ym), the reference judgment value (y 1) ~ (ym) the larger area value is even one product To be defective.
上記画像処理装置(14)の画像処理は第9図に示すよ
うなフローチャートで示される。The image processing of the image processing device (14) is shown by a flowchart as shown in FIG.
上記検査装置はスコープ(11)及びコーンミラー(1
2)を円筒内壁面(16)に挿入して検査する際、撮像カ
メラ(10)を下方か上方へ若しくは上方から下方へ順次
移動させ、第8図に示す様に撮像領域が一部オーバーラ
ップするように撮像する。The above inspection equipment consists of a scope (11) and a cone mirror (1
When inserting 2) into the cylindrical inner wall surface (16) for inspection, the imaging camera (10) is sequentially moved downward, upward or downward from above, and the imaging areas partially overlap as shown in FIG. The image is taken as follows.
このオーバーラップ幅(h)は不良となる欠陥径に合
わせておく。The overlap width (h) is set in accordance with the diameter of the defective defect.
上記の如き構成を有する検査装置は、検査時、スコー
プ(11)及びコーンミラー(12)を検査を行う円筒内壁
面(6)内に挿入し、その中心軸に沿って移動させ、所
定距離毎に光源(19)を発光させて光ファイバ(20)を
介して円筒内壁面(16)を照らし、円筒内壁面(16)の
一定の領域をコーンミラー(12)にて反射させ、スコー
プ(11)を通して撮像カメラ(10)に撮像させる。そし
て撮像した入力画像を画像処理装置(14)へ送り、上記
した画像処理を行って欠陥の有無を検査を行い、不良の
欠陥が1つでも発見されると、不良品とする。In the inspection apparatus having the above-described configuration, at the time of inspection, the scope (11) and the cone mirror (12) are inserted into the cylindrical inner wall surface (6) to be inspected, moved along the central axis thereof, and each predetermined distance. A light source (19) emits light to illuminate the inner wall surface (16) of the cylinder via an optical fiber (20), and a certain area of the inner wall surface (16) is reflected by a cone mirror (12) to form a scope (11). ) Through the imaging camera (10). The captured input image is sent to the image processing device (14), and the above-described image processing is performed to check for the presence or absence of a defect. If at least one defective defect is found, it is determined to be defective.
尚、上記検査装置をシリンダブロック(25)のボア
(26)内面の検査に用いる場合は、第9図に示す様に、
撮像カメラ(10)及びスコープ(11)、コーンミラー
(12)、光源(19)、光ファイバ(20)等をシリンダブ
ロック(25)のボア数と同じ数量を用意し、全ボア(2
6)内面を同時に検査するようにすればよい。またタク
トタイムが長い場合にはその時間に合わせて、1ボアず
つ若しくは2ボアずつ順番に検査するようにしてもよ
い。When the above inspection device is used to inspect the inner surface of the bore (26) of the cylinder block (25), as shown in FIG.
Prepare the same number of imaging cameras (10) and scopes (11), cone mirrors (12), light sources (19), optical fibers (20), etc. as the number of bores in the cylinder block (25).
6) The inner surface should be inspected at the same time. If the tact time is long, the inspection may be performed one by one or two at a time in accordance with the time.
この発明によれば、撮像カメラを回転させることなく
上下動させるだけで、円筒内壁面の輪切りにされた周面
全周を順番に撮像して、該円筒内壁面内の欠陥を自動的
に検査でき、しかも撮像カメラからの入力画像に対して
常に検査領域を設定するので、円筒内壁面の上下端付近
のように入力画像に円筒内壁面以外の背景部分が入って
いても、該背景部分を検査領域から除外でき、正確な欠
陥検査を行える。According to the present invention, by simply moving the imaging camera up and down without rotating it, the entire circumference of the inner surface of the cylindrical inner wall is sequentially imaged, and defects in the inner wall surface of the cylinder are automatically inspected. In addition, since the inspection area is always set for the input image from the imaging camera, even if the input image includes a background portion other than the cylindrical inner wall surface, such as near the upper and lower ends of the cylindrical inner wall surface, the background portion is not changed. It can be excluded from the inspection area and can perform accurate defect inspection.
従って、この検査方法をエンジンのシリンダブロック
やその他の部品の形成された円筒内壁面の欠陥検査に適
用すれば、該検査を自動化でき、作業者の負担を軽減す
ることができると共に正確な検査を行え、信頼性が大幅
に向上する。Therefore, if this inspection method is applied to a defect inspection of the cylinder inner wall surface on which the cylinder block and other parts of the engine are formed, the inspection can be automated, the burden on the operator can be reduced, and an accurate inspection can be performed. And reliability is greatly improved.
第1図は本発明方法に用いる検査装置の構成を示す正面
図、第2図はコーンミラーによる反射像の特性を示す原
理図、第3図乃至第7図は画像処理を示す原理図、第8
図は撮像領域を示す一部破断斜視図、第9図は画像処理
のフローチャート、第10図は他の検査装置を示す斜視
図、第11図は従来の検査装置の正面図、第12図及び第13
図は問題点を示す原理図である。 (10)……撮像カメラ、(11)……スコープ、 (12)……コーンミラー、(14)……画像処理装置。FIG. 1 is a front view showing a configuration of an inspection apparatus used in the method of the present invention, FIG. 2 is a principle view showing characteristics of a reflected image by a cone mirror, FIGS. 3 to 7 are principle views showing image processing, FIG. 8
FIG. 9 is a partially broken perspective view showing an imaging region, FIG. 9 is a flowchart of image processing, FIG. 10 is a perspective view showing another inspection apparatus, FIG. 11 is a front view of a conventional inspection apparatus, FIG. Thirteenth
The figure is a principle diagram showing a problem. (10) an imaging camera, (11) a scope, (12) a cone mirror, (14) an image processing device.
フロントページの続き (58)調査した分野(Int.Cl.6,DB名) G01N 21/84 - 21/90Continuation of front page (58) Field surveyed (Int.Cl. 6 , DB name) G01N 21/84-21/90
Claims (1)
像カメラの下方に垂設した小径の探査用スコープと、前
記スコープの下方に同芯状に設置した円錐形状のコーン
ミラーと、前記撮像カメラにて撮像された画像を画像処
理する画像処理装置とを備え、前記スコープの下方及び
コーンミラーを円筒内壁面内にその中心軸に沿って挿入
して円筒内壁面の周面を撮像し、前記画像処理装置にお
いて、前記撮像カメラからの入力画像に対して水平方向
及び垂直方向のヒストグラムをとってその画像中心を求
め、この中心を基準としてドーナツ状に検査領域を設定
し、かつ、前記画像中心を中心とする等幅同芯リング状
の複数の判定領域を設定し、各判定領域毎に画像円周方
向の収縮歪に対応させて欠陥面積の判定基準値を設定
し、前記検査領域から微分処理及び2値化処理で得られ
た欠陥面積値と前記判定基準値とを比較演算し、前記判
定基準値よりも大きな欠陥面積値があるか否かによって
欠陥の有無を判定するようにしたことを特徴とする円筒
内壁面の欠陥の検査方法。1. An imaging camera supported so as to be able to move up and down, a small-diameter exploration scope vertically suspended below the imaging camera, a conical cone mirror installed concentrically below the scope, and the imaging An image processing device that performs image processing of an image captured by a camera, and the lower part of the scope and a cone mirror are inserted along the central axis into the cylindrical inner wall surface to image the peripheral surface of the cylindrical inner wall surface, In the image processing apparatus, a horizontal and vertical histograms are obtained for an input image from the imaging camera to determine the center of the image, and a donut-shaped inspection area is set based on the center, and the image is obtained. A plurality of equal-width concentric ring-shaped judgment areas centered on the center are set, and a judgment reference value of a defect area is set for each judgment area in correspondence with the shrinkage strain in the image circumferential direction. The defect area value obtained by the differentiation process and the binarization process is compared with the determination reference value, and the presence or absence of a defect is determined based on whether or not there is a defect area value larger than the determination reference value. A method for inspecting defects on the inner wall surface of a cylinder, characterized in that:
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2143345A JP2839934B2 (en) | 1990-05-31 | 1990-05-31 | Inspection method for defects on the inner wall of the cylinder |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2143345A JP2839934B2 (en) | 1990-05-31 | 1990-05-31 | Inspection method for defects on the inner wall of the cylinder |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH0436644A JPH0436644A (en) | 1992-02-06 |
JP2839934B2 true JP2839934B2 (en) | 1998-12-24 |
Family
ID=15336630
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2143345A Expired - Fee Related JP2839934B2 (en) | 1990-05-31 | 1990-05-31 | Inspection method for defects on the inner wall of the cylinder |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP2839934B2 (en) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5973734A (en) | 1997-07-09 | 1999-10-26 | Flashpoint Technology, Inc. | Method and apparatus for correcting aspect ratio in a camera graphical user interface |
US6317141B1 (en) | 1998-12-31 | 2001-11-13 | Flashpoint Technology, Inc. | Method and apparatus for editing heterogeneous media objects in a digital imaging device |
JP2002208738A (en) * | 2001-01-11 | 2002-07-26 | Nec Machinery Corp | Illuminator and apparatus for inspecting tubular work using the same |
JP4979271B2 (en) | 2006-05-29 | 2012-07-18 | オリンパス株式会社 | ENDOSCOPE SYSTEM AND ENDOSCOPE OPERATING METHOD |
US9224145B1 (en) | 2006-08-30 | 2015-12-29 | Qurio Holdings, Inc. | Venue based digital rights using capture device with digital watermarking capability |
SK500082010A3 (en) * | 2010-03-17 | 2011-10-04 | Datalan, A.S. | Method of control passable channel product, especially an aqueous core of the cylinder head and a device for implementing this method |
JP6294763B2 (en) * | 2014-05-26 | 2018-03-14 | 日本電産トーソク株式会社 | Inner surface inspection device |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH065616Y2 (en) * | 1986-05-28 | 1994-02-09 | 三菱原子燃料株式会社 | Pipe inner surface inspection device |
JPS6348444A (en) * | 1986-08-19 | 1988-03-01 | Narumi China Corp | Method and device for automatic inspection of surface of glass substrate |
JP2503408Y2 (en) * | 1986-10-31 | 1996-07-03 | 株式会社レアックス | Hole wall fixed orientation omnidirectional photographing device |
JPS6415641A (en) * | 1987-07-09 | 1989-01-19 | Petroleum Energy Center Found | Apparatus for inspecting inside of tube |
-
1990
- 1990-05-31 JP JP2143345A patent/JP2839934B2/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
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JPH0436644A (en) | 1992-02-06 |
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