JP5306700B2 - Ultrasonic thickness measurement method - Google Patents
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Abstract
Description
本発明は、超音波を用いて対象物（例えば、配管又は板）の厚み測定を行う超音波による厚み測定方法に関する。 The present invention relates to an ultrasonic thickness measurement method for measuring the thickness of an object (for example, a pipe or a plate) using ultrasonic waves.
従来、配管（対象物）の厚み測定方法として、超音波を使用する方法がある。
この厚み測定は、配管に超音波探触子から超音波を発し、反射エコーを検出して行っているが、反射エコーには、配管の厚みによるものだけでなく、他の妨害エコー（例えば、塗装の剥離によるもの）も含まれている。
そこで、配管の厚みによる反射エコーのみを検出するため、例えば、特許文献１のように、反射エコーのレベルにしきい値（スレシュホールド）を設ける方法や、また、検出した反射エコーで最初に現れたピーク（ファーストピーク）を用いる方法が採用されている。
Conventionally, there is a method of using ultrasonic waves as a method for measuring the thickness of a pipe (object).
This thickness measurement is performed by emitting an ultrasonic wave from the ultrasonic probe to the pipe and detecting a reflected echo. The reflected echo is not only due to the thickness of the pipe, but also other interference echoes (for example, It is also included due to paint peeling.
Therefore, in order to detect only the reflected echo due to the thickness of the pipe, for example, as shown in Patent Document 1, a method of providing a threshold value (threshold) to the level of the reflected echo, or the detected reflected echo first appeared. A method using a peak (first peak) is employed.
しかしながら、前記従来の方法には、未だ解決すべき以下のような問題があった。
反射エコーのレベルにしきい値を設ける場合、例えば、配管の厚みによる反射エコーが減衰したとき、そのしきい値の設定レベルによっては、配管の厚みによる反射エコーと共に妨害エコーが検出される場合や、また双方のエコーが検出されない場合があり、配管の厚みの測定精度が低下する恐れがある。
更に、検出した反射エコーで最初に現れたピークを使用する場合は、そのピークが配管の厚みによるものでなく、妨害エコーによるものであれば、配管の厚みの測定精度が低下する問題がある。
However, the conventional method still has the following problems to be solved.
When a threshold value is provided for the level of the reflected echo, for example, when the reflected echo due to the thickness of the pipe is attenuated, depending on the setting level of the threshold, when the interference echo is detected together with the reflected echo due to the thickness of the pipe, Moreover, both echoes may not be detected, and the measurement accuracy of the pipe thickness may be reduced.
Further, when using the peak first appearing in the detected reflected echo, if the peak is not caused by the thickness of the pipe but is caused by the interference echo, there is a problem that the measurement accuracy of the thickness of the pipe is lowered.
本発明はかかる事情に鑑みてなされたもので、対象物の厚みによる反射エコーのみを自動的に抽出でき、対象物の厚み測定を精度よく実施できる超音波による厚み測定方法を提供することを目的とする。 The present invention has been made in view of such circumstances, and an object of the present invention is to provide an ultrasonic thickness measurement method that can automatically extract only a reflected echo due to the thickness of an object and can accurately measure the thickness of the object. And
前記目的に沿う本発明に係る超音波による厚み測定方法は、対象物の厚み測定範囲内の各測定位置で、超音波探触子から超音波を発して反射エコーの波形をそれぞれ検出する測定工程と、
前記対象物の厚み方向Ｚの検出範囲を設定し、前記測定工程で検出した前記各波形からピークをそれぞれ検出するピーク検出工程と、
前記測定工程と前記ピーク検出工程から得られた前記対象物の形状に対応した３次元の仮想空間を作成し、該仮想空間を、前記対象物の長さ方向Ｘ、幅方向Ｙ、及び厚み方向Ｚにそれぞれ区分して、多数の領域を形成し、前記ピーク検出工程で得られた複数の前記ピークの位置を、前記各領域にそれぞれ振り分け、該各領域ごとに前記ピークの数を積算するピーク振分け工程と、
前記ピークの数が積算された連続する前記領域を連結し、複数のグループを形成するグループ化工程と、
前記グループ化工程で形成され、前記対象物の長さ方向Ｘ、幅方向Ｙ、及び厚み方向Ｚに連続した前記グループを構成する領域から、不連続となる前記グループを構成する領域を分離して、前記対象物の厚みを求める厚み演算工程とを有し、
前記グループ化工程で形成される前記複数のグループのうち、該各グループを構成する前記領域の全ての前記ピークの数の合計値が大きいものから２つのグループを選択して、前記対象物の厚み方向Ｚの位置が小さい方をＢ１エコーのグループとし、大きい方をＢ２エコーのグループとして、該２つのグループを前記厚み演算工程の前記連続したグループとする。
The ultrasonic thickness measurement method according to the present invention that meets the above-described object is a measurement process in which an ultrasonic wave is emitted from an ultrasonic probe at each measurement position within a thickness measurement range of an object and a waveform of a reflected echo is detected. When,
A peak detection step of setting a detection range in the thickness direction Z of the object, and detecting a peak from each waveform detected in the measurement step;
A three-dimensional virtual space corresponding to the shape of the object obtained from the measurement step and the peak detection step is created, and the virtual space is divided into a length direction X, a width direction Y, and a thickness direction of the object. A peak that is divided into Z and forms a large number of regions, the positions of the plurality of peaks obtained in the peak detection step are respectively assigned to the regions, and the number of peaks is integrated for each region. A distribution process;
A grouping step of connecting the continuous regions in which the number of peaks is integrated to form a plurality of groups;
A region forming the discontinuous group is separated from a region forming the group formed in the grouping step and continuous in the length direction X, the width direction Y, and the thickness direction Z of the object. , possess a thickness calculating step of obtaining the thickness of the object,
Among the plurality of groups formed in the grouping step, select two groups having a large total value of the number of all the peaks in the region constituting each group, and the thickness of the object The smaller one in the direction Z is the B1 echo group, the larger one is the B2 echo group, and the two groups are the continuous groups in the thickness calculation step .
本発明に係る超音波による厚み測定方法において、前記グループ化工程で形成される前記複数のグループに、前記対象物の厚み方向Ｚの位置が前記Ｂ１エコーのグループより小さいグループＧがあり、前記Ｂ１エコーのグループで形成される前記対象物の長さ方向Ｘと幅方向ＹのＸＹ平面上で、前記グループＧを投影した位置に空白部分が存在するときは、前記対象物に孔食が発生していると判断し、前記グループＧを前記Ｂ１エコーのグループに併合することが好ましい。 In the ultrasonic thickness measurement method according to the present invention, the plurality of groups formed in the grouping step includes a group G in which the position of the object in the thickness direction Z is smaller than the B1 echo group, and the B1 When a blank portion exists at the position where the group G is projected on the XY plane in the length direction X and the width direction Y of the object formed by echo groups, pitting corrosion occurs on the object. Preferably, the group G is merged with the B1 echo group.
本発明に係る超音波による厚み測定方法において、前記グループ化工程で形成される前記複数のグループに、前記対象物の厚み方向Ｚの位置が前記Ｂ１エコーのグループより小さいグループＧがあり、前記Ｂ１エコーのグループ内に、該Ｂ１エコーのグループを構成する前記領域のピーク値よりも小さいピーク値の領域が存在するときは、前記対象物に孔食が発生していると判断し、前記グループＧを前記Ｂ１エコーのグループに併合することが好ましい。 In the ultrasonic thickness measurement method according to the present invention, the plurality of groups formed in the grouping step includes a group G in which the position of the object in the thickness direction Z is smaller than the B1 echo group, and the B1 When a region having a peak value smaller than the peak value of the region constituting the B1 echo group exists in the echo group, it is determined that pitting corrosion has occurred in the object, and the group G Are preferably merged into the B1 echo group.
請求項１〜３記載の超音波による厚み測定方法は、測定工程、ピーク検出工程、ピーク振分け工程、グループ化工程、及び厚み演算工程を有するので、従来のように、対象物の厚みによる反射エコーが顕著に現れるようなしきい値を設定する必要がなく、また検出した反射エコーで最初に現れたピークを使用する必要もなく、対象物の厚みによる反射エコーのみを自動的に抽出でき、対象物の厚み測定を精度よく実施できる。 Since the ultrasonic thickness measurement method according to claims 1 to 3 includes a measurement step, a peak detection step, a peak distribution step, a grouping step, and a thickness calculation step, the reflection echo due to the thickness of the object as in the prior art. It is not necessary to set a threshold value that makes the image appear prominent, and it is not necessary to use the peak that first appears in the detected reflected echo, and only the reflected echo due to the thickness of the object can be automatically extracted. Thickness measurement can be performed with high accuracy.
特に、各グループを構成する領域の全てのピークの数の合計値が大きいものから２つのグループを選択し、これを対象物の長さ方向Ｘ、幅方向Ｙ、及び厚み方向Ｚに連続したグループとするので、対象物の厚みによる反射エコーを容易に検出できる。これは、対象物の形状を現すグループのピークの合計値が、妨害エコーによる不連続となるグループのピークの合計値と比べて多いことによる。 In particular , two groups are selected from those having a large total value of the number of all peaks in the regions constituting each group , and these groups are consecutive in the length direction X, the width direction Y, and the thickness direction Z of the object. Therefore, the reflected echo due to the thickness of the object can be easily detected. This is because the total value of the peaks of the group representing the shape of the object is larger than the total value of the peaks of the group that becomes discontinuous due to the interference echo.
請求項２、３記載の超音波による厚み測定方法において、対象物に孔食が存在する場合、対象物の厚み方向Ｚの位置が急激に変化するため、本来併合されるグループとは異なる別のグループに併合されてしまう恐れがあるが、この問題がなくなる。 In the thickness measurement method using ultrasonic waves according to claims 2 and 3 , when pitting corrosion is present in the object, the position in the thickness direction Z of the object changes abruptly. There is a risk of merging into a group, but this problem disappears.
続いて、添付した図面を参照しつつ、本発明を具体化した実施の形態につき説明し、本発明の理解に供する。
ここで、図１は本発明の一実施の形態に係る超音波による厚み測定方法のグループ化工程の説明図、図２は同超音波による厚み測定方法の測定工程で得られた超音波の全波形の説明図、図３は同超音波による厚み測定方法のグループ化工程での孔食部分の併合を示す説明図である。
Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
Here, FIG. 1 is an explanatory diagram of a grouping process of the ultrasonic thickness measuring method according to one embodiment of the present invention, and FIG. 2 is a diagram illustrating all ultrasonic waves obtained in the measuring process of the ultrasonic thickness measuring method. FIG. 3 is an explanatory view showing the merging of pitting corrosion portions in the grouping step of the thickness measurement method using the same ultrasonic waves.
図１、図２に示すように、本発明の一実施の形態に係る超音波による厚み測定方法は、測定工程、ピーク検出工程、ピーク振分け工程、グループ化工程、及び厚み演算工程を有し、配管（対象物の一例）の厚み測定範囲内の各測定位置で、超音波探触子から超音波を発して、超音波の全波形（Ａスコープともいう）から配管の厚みによる反射エコー（底面エコーともいう）のみを自動的に抽出する方法である。以下、詳しく説明する。 As shown in FIGS. 1 and 2, the ultrasonic thickness measurement method according to an embodiment of the present invention includes a measurement process, a peak detection process, a peak distribution process, a grouping process, and a thickness calculation process. At each measurement position within the thickness measurement range of the pipe (an example of an object), an ultrasonic wave is emitted from the ultrasonic probe, and a reflected echo (bottom surface) is generated from the entire ultrasonic waveform (also referred to as an A scope). This is a method of automatically extracting only (also called echo). This will be described in detail below.
厚み測定は、配管に超音波探触子から超音波を発し、反射されるエコーの波形を検出して行っているが、得られた超音波の全波形から、配管の厚みによる反射エコーのみを自動的に抽出することは、その他の反射エコー（即ち、妨害エコー）が妨害して困難である。
そこで、全ての反射エコーを、３次元の仮想空間に格子状に設定した領域（以下、セル又は格子ともいう）に振り分け、隣接したセルをグループ化することにより、配管の厚みによる反射エコーのみを分離する。この計算手順を以下に示すが、この方法は、ピーク検出手段、ピーク振分け手段、グループ化手段、厚み演算手段、及び記憶手段を有する測定装置に適用され、各手段は、例えば、コンピュータに搭載されたプログラムによって構成されている。
Thickness measurement is performed by emitting an ultrasonic wave from the ultrasonic probe to the pipe and detecting the reflected echo waveform. From the entire waveform of the obtained ultrasonic wave, only the reflected echo due to the pipe thickness is obtained. It is difficult to extract automatically because other reflected echoes (ie, disturbing echoes) are disturbed.
Therefore, all the reflected echoes are distributed to a region (hereinafter also referred to as a cell or a lattice) set in a lattice shape in a three-dimensional virtual space, and adjacent cells are grouped, so that only the reflected echo due to the thickness of the pipe is obtained. To separate. This calculation procedure is shown below. This method is applied to a measuring apparatus having a peak detection means, a peak distribution means, a grouping means, a thickness calculation means, and a storage means, and each means is mounted on a computer, for example. It is configured by a program.
まず、測定工程を行う。
配管の厚み測定は、配管の表面に対して超音波探触子を所定ピッチ（例えば、１ｍｍ）で配管の軸方向（ＸＹ平面のＸ軸となる方向）に移動させ、この各位置において、超音波探触子を配管の周方向（ＸＹ平面のＹ軸となる方向）に、所定ピッチ（例えば、１ｍｍ）で走査させ、各位置で図２に示す超音波の全波形を収録する。なお、上記した所定ピッチは、Ｘ軸方向に、例えば０．５〜３ｍｍの範囲内、Ｙ軸方向に、例えば０．５〜３ｍｍの範囲内で、それぞれ調整できる。
この収録された超音波の全波形は、記憶手段に送信され保存される。
First, a measurement process is performed.
The thickness of the pipe is measured by moving the ultrasonic probe with respect to the pipe surface at a predetermined pitch (for example, 1 mm) in the axial direction of the pipe (in the direction of the X axis of the XY plane). The ultrasonic probe is scanned at a predetermined pitch (for example, 1 mm) in the circumferential direction of the pipe (in the direction of the Y axis on the XY plane), and the entire ultrasonic waveform shown in FIG. 2 is recorded at each position. The predetermined pitch can be adjusted in the X-axis direction, for example, within a range of 0.5 to 3 mm, and in the Y-axis direction, for example, within a range of 0.5 to 3 mm.
All the recorded ultrasonic waveforms are transmitted to and stored in the storage means.
そして、ピーク検出工程では、ピーク検出手段により、配管の厚み方向Ｚの検出範囲を設定し、記憶手段に保存された各々の波形からピーク（ここでは、配管の第１回底面エコー（Ｂ１エコー）、第２回底面エコー（Ｂ２エコー）、及び妨害エコーのピークを含む６個のピーク）を検出する（分解能は０．１ｍｍ以下）。なお、検出できるピークの数は、図２に示すように、スレシュホールド（図２中の点線）を設定し、検出レベルを規定することで調整できる（例えば、１０個以下、更には６個以下）。このピークは、検出レベルが大きいものから複数検出されるため、例えば、配管の厚みによる反射エコーと他の反射エコーの強度が同程度であっても、配管の厚みによる反射エコーを検出できる。
これにより、配管の厚み方向Ｚで検出された反射エコーの検出範囲が分かるので、これを記憶手段に保存する。
In the peak detection step, the detection range in the thickness direction Z of the pipe is set by the peak detection means, and the peak (here, the first bottom echo (B1 echo) of the pipe is determined from each waveform stored in the storage means. , 2nd bottom echo (B2 echo), and 6 peaks including peaks of disturbing echo) (resolution is 0.1 mm or less). As shown in FIG. 2, the number of peaks that can be detected can be adjusted by setting a threshold (dotted line in FIG. 2) and defining the detection level (for example, 10 or less, and further 6 or less). ). Since a plurality of peaks are detected from those having a large detection level, for example, even if the reflected echo due to the pipe thickness and the intensity of the other reflected echo are approximately the same, the reflected echo due to the pipe thickness can be detected.
Thereby, since the detection range of the reflected echo detected in the thickness direction Z of the pipe is known, this is stored in the storage means.
次に、ピーク振分け工程を行う。
ここでは、ピーク振分け手段により、測定工程とピーク検出工程から得られた配管の形状に対応した３次元の仮想空間（ＸＹＺ空間）を作成し、この仮想空間を、対象物の長さ方向Ｘ、幅方向Ｙ、及び厚み方向Ｚにそれぞれ区分して、多数のセルを形成し、これを記憶手段に保存する。このセルの大きさは、例えば、Ｘ軸方向：１ｍｍ、Ｙ軸方向：１ｍｍ、Ｚ軸方向：０．２ｍｍである。なお、セルのＸ軸方向及びＹ軸方向の大きさは、前記した超音波の全波形の収録位置に応じて調整でき、またセルのＺ軸方向の大きさは、配管の厚み測定精度に応じて、例えば、０．０５〜３ｍｍの範囲内で調整できる。
ここで、作成された全てのセルの属性値を「０」とし、これを記憶手段に保存する。
Next, a peak distribution step is performed.
Here, a three-dimensional virtual space (XYZ space) corresponding to the shape of the pipe obtained from the measurement step and the peak detection step is created by the peak distribution means, and this virtual space is defined as the length direction X, Dividing into the width direction Y and the thickness direction Z, a large number of cells are formed and stored in the storage means. The size of this cell is, for example, X-axis direction: 1 mm, Y-axis direction: 1 mm, and Z-axis direction: 0.2 mm. The size of the cell in the X-axis direction and the Y-axis direction can be adjusted according to the recording position of all the ultrasonic waveforms described above, and the size of the cell in the Z-axis direction depends on the pipe thickness measurement accuracy. For example, it can adjust within the range of 0.05-3 mm.
Here, the attribute values of all the created cells are set to “0” and stored in the storage means.
そして、前記したピーク検出工程で得られ記憶手段に保存された複数のピークを、超音波探触子の位置から得られるＸ軸方向及びＹ軸方向の位置座標と、全波形のピークの位置から得られる配管の厚み方向Ｚの位置座標から、その位置座標を含むセルにそれぞれ振り分け、各セルごとにピークの数を積算して、各セルの属性値をそれぞれ決定し、これを記憶手段に保存する。
具体的には、属性値が「０」のセルに１つのピークが振り分けられた場合、その属性値を「１」とし、ピークが振り分けられるごとに、その属性値をカウントアップする。一方、ピークが振り分けられなければ、セルの属性値は「０」のままである。
Then, the plurality of peaks obtained in the above-described peak detection step and stored in the storage means are obtained from the position coordinates in the X-axis direction and the Y-axis direction obtained from the position of the ultrasonic probe, and the peak positions of all waveforms. From the position coordinates in the thickness direction Z of the obtained pipe, it is assigned to each cell including the position coordinates, the number of peaks is accumulated for each cell, the attribute value of each cell is determined, and this is stored in the storage means To do.
Specifically, when one peak is assigned to a cell having an attribute value “0”, the attribute value is set to “1”, and the attribute value is counted up each time a peak is assigned. On the other hand, if the peak is not distributed, the attribute value of the cell remains “0”.
次に、グループ化工程を行う。
ここでは、グループ化手段により、ピークの数が積算されたセル、即ち属性値が「０」でないセルを中心に、上下左右斜めの全２６方向のいずれかに、属性値が「０」でないセルがある場合、これを連結して記憶手段に保存する。これにより、属性値が「０」でない複数のセルが連続するため、複数のグループが形成されることになる。
なお、セルを連結するに際しては、各セルに同一のグループ番号を付すが、この番号が付されたセルのピークにも、同一のグループ番号を付す。
Next, a grouping process is performed.
Here, a cell in which the attribute value is not “0” in any of all 26 directions, up, down, left and right diagonally, centering on a cell in which the number of peaks is integrated by the grouping means, ie, a cell whose attribute value is not “0”. If there are, they are concatenated and stored in the storage means. As a result, a plurality of cells whose attribute values are not “0” are continuous, so that a plurality of groups are formed.
When cells are connected, the same group number is assigned to each cell, and the same group number is also assigned to the peak of the cell to which this number is assigned.
この形成された複数のグループについて、各グループを構成する全セルの全てのピークの数を積算し、その合計値が大きいものから２つのグループを選択する。そして、配管の厚み方向Ｚの位置（以下、Ｚ軸方向の位置ともいう）が小さい方をＢ１エコーのグループとし、大きい方をＢ２エコーのグループとして、記憶手段に保存する。
これにより、図１に示すように、配管の長さ方向Ｘ、幅方向Ｙ、及び厚み方向Ｚに連続したグループ、即ちＢ１エコーのグループ及びＢ２エコーのグループと、不連続となる妨害エコーのグループが、それぞれ形成される。
For the plurality of formed groups, the numbers of all the peaks of all the cells constituting each group are integrated, and two groups are selected from those having a large total value. Then, the smaller one of the pipes in the thickness direction Z (hereinafter also referred to as the position in the Z-axis direction) is stored in the storage means as the B1 echo group and the larger one as the B2 echo group.
As a result, as shown in FIG. 1, a group that is continuous in the length direction X, the width direction Y, and the thickness direction Z of the pipe, that is, a group of B1 echoes and a group of B2 echoes, and a group of discontinuous interference echoes. Are formed respectively.
ここで、配管に面食がある場合、Ｚ軸方向（配管の厚み方向）の位置の値の変動は緩やかであるため、連続するセルはグループ化され易い。しかし、図３に示すように、配管に孔食が発生し、局部的な凹み部が存在している箇所では、Ｚ軸方向の位置が急変するため、凹み部により形成されるグループＧが、併合されるべき適正なグループに併合されず、異なる別のグループにグループ化されてしまう場合がある。
孔食が発生している箇所では、超音波が凹み部で反射されるので、凹み部が振動子の寸法より大きい場合は、本来Ｂ１エコーが現れる箇所にエコーが現れないため、Ｂ１エコーのグループに空白部分が生じる。
従って、配管の厚み方向Ｚの位置がＢ１エコーのグループより小さいグループＧがあり、Ｂ１エコーのグループで形成される配管の長さ方向Ｘと幅方向ＹのＸＹ平面上で、グループＧを投影した位置に空白部分（属性が０）が存在するときは、配管に孔食が発生していると判断し、グループＧをＢ１エコーのグループに併合して、記憶手段に保存する。
Here, when there is a surface corrosion in the pipe, the variation in the value of the position in the Z-axis direction (the thickness direction of the pipe) is gentle, so that continuous cells are easily grouped. However, as shown in FIG. 3, pitting corrosion occurs in the pipe, and the position in the Z-axis direction changes abruptly at the location where the local recess is present, so the group G formed by the recess is It may not be merged into the proper group to be merged and may be grouped into a different group.
Since the ultrasonic waves are reflected by the dents at the places where pitting corrosion has occurred, if the dents are larger than the size of the vibrator, no echoes will appear where B1 echoes originally appear. Produces a blank space.
Therefore, there is a group G in which the position in the thickness direction Z of the pipe is smaller than the B1 echo group, and the group G is projected on the XY plane in the length direction X and the width direction Y of the pipe formed by the B1 echo group. When a blank portion (attribute is 0) exists at the position, it is determined that pitting corrosion has occurred in the pipe, and the group G is merged with the B1 echo group and stored in the storage means.
一方、凹み部が振動子の寸法より小さいときは、凹み部からのエコーの後ろに、凹み部周辺から反射したＢ１エコーも同時に現れるため、Ｂ１グループ内に空白部分ができない場合がある。しかし、孔食がないときのＢ１エコーのエコー高さと比較すると、エコー高さが低いので、Ｂ１エコーのグループに、周囲よりもエコー高さが低い範囲、即ちグループＧが生じる。
従って、配管の厚み方向Ｚの位置がＢ１エコーのグループより小さいグループＧがあり、Ｂ１エコーのグループ内に、Ｂ１エコーのグループを構成する領域のピーク値よりも小さいピーク値の領域が存在するときは、配管に孔食が発生していると判断し、グループＧをＢ１エコーのグループに併合して、記憶手段に保存する。
On the other hand, when the dent is smaller than the size of the vibrator, the B1 echo reflected from the periphery of the dent also appears at the same time behind the echo from the dent, so that there may be no blank portion in the B1 group. However, since the echo height is low compared to the echo height of the B1 echo when there is no pitting corrosion, a range in which the echo height is lower than the surroundings, that is, the group G is generated in the B1 echo group.
Accordingly, when there is a group G in which the position in the thickness direction Z of the pipe is smaller than the B1 echo group, and there is a peak value area within the B1 echo group that is smaller than the peak value of the area constituting the B1 echo group. Determines that pitting corrosion has occurred in the pipe, merges the group G with the group of B1 echoes, and stores them in the storage means.
続いて、厚み演算工程を行う。
ここでは、厚み演算手段により、Ｂ１エコーのグループ番号をもつ全ての波形のピークの位置から、配管の厚みを計算することにより、その厚みを計算できる。
また、全ての波形において、Ｂ１エコーのグループ番号をもつピークの位置と、Ｂ２エコーのグループ番号をもつピークの位置の差により、配管の厚みを計算することもできる。この方法を用いることで、例えば、配管の表面に塗装があるような場合には、塗装を除いた厚みを計算できる。
Subsequently, a thickness calculation step is performed.
Here, the thickness can be calculated by calculating the thickness of the pipe from the positions of the peaks of all the waveforms having the group number of the B1 echo by the thickness calculating means.
In all the waveforms, the pipe thickness can be calculated from the difference between the peak position having the B1 echo group number and the peak position having the B2 echo group number. By using this method, for example, when there is a coating on the surface of the pipe, the thickness excluding the coating can be calculated.
以上の方法で、超音波探触子により測定された配管の厚みを、例えば、ロータリエンコーダ又はマイクロエンコーダで得られた測定位置と共に、コンピュータのディスプレイにより表示できる。なお、この出力に際しては、配管の全表面を展開状態で示し、しかも配管の厚みを色分け表示してよい。
これにより、配管の厚みによる反射エコーのみを自動的に抽出でき、配管の厚み測定を精度よく実施できる。
With the above method, the thickness of the pipe measured by the ultrasonic probe can be displayed on the computer display together with the measurement position obtained by the rotary encoder or the micro encoder, for example. In this output, the entire surface of the pipe may be shown in an unfolded state, and the pipe thickness may be displayed in different colors.
Thereby, only the reflection echo by the thickness of piping can be extracted automatically, and the thickness measurement of piping can be implemented accurately.
以上、本発明を、実施の形態を参照して説明してきたが、本発明は何ら上記した実施の形態に記載の構成に限定されるものではなく、特許請求の範囲に記載されている事項の範囲内で考えられるその他の実施の形態や変形例も含むものである。例えば、前記したそれぞれの実施の形態や変形例の一部又は全部を組合せて本発明の超音波による厚み測定方法を構成する場合も本発明の権利範囲に含まれる。
また、前記実施の形態においては、厚み測定を行う対象物として金属製の配管を使用した場合について説明したが、他の材質、例えば、磁性を有しない金属、セラミックス、プラスチック、又はゴムで構成された配管でもよく、またこれらの材質で構成される板でもよい。
As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the configuration described in the above embodiment, and the matters described in the scope of claims. Other embodiments and modifications conceivable within the scope are also included. For example, a case where the ultrasonic thickness measurement method of the present invention is configured by combining a part or all of the above-described embodiments and modifications is also included in the scope of the right of the present invention.
In the above embodiment, the case where a metal pipe is used as an object for measuring the thickness has been described. However, the pipe is made of another material, for example, a metal having no magnetism, ceramics, plastic, or rubber. Piping may be sufficient, and the board comprised with these materials may be sufficient.
Claims (3)
前記対象物の厚み方向Ｚの検出範囲を設定し、前記測定工程で検出した前記各波形からピークをそれぞれ検出するピーク検出工程と、
前記測定工程と前記ピーク検出工程から得られた前記対象物の形状に対応した３次元の仮想空間を作成し、該仮想空間を、前記対象物の長さ方向Ｘ、幅方向Ｙ、及び厚み方向Ｚにそれぞれ区分して、多数の領域を形成し、前記ピーク検出工程で得られた複数の前記ピークの位置を、前記各領域にそれぞれ振り分け、該各領域ごとに前記ピークの数を積算するピーク振分け工程と、
前記ピークの数が積算された連続する前記領域を連結し、複数のグループを形成するグループ化工程と、
前記グループ化工程で形成され、前記対象物の長さ方向Ｘ、幅方向Ｙ、及び厚み方向Ｚに連続した前記グループを構成する領域から、不連続となる前記グループを構成する領域を分離して、前記対象物の厚みを求める厚み演算工程とを有し、
前記グループ化工程で形成される前記複数のグループのうち、該各グループを構成する前記領域の全ての前記ピークの数の合計値が大きいものから２つのグループを選択して、前記対象物の厚み方向Ｚの位置が小さい方をＢ１エコーのグループとし、大きい方をＢ２エコーのグループとして、該２つのグループを前記厚み演算工程の前記連続したグループとすることを特徴とする超音波による厚み測定方法。 At each measurement position within the thickness measurement range of the object, a measurement process for detecting the waveform of the reflected echo by emitting an ultrasonic wave from the ultrasonic probe,
A peak detection step of setting a detection range in the thickness direction Z of the object, and detecting a peak from each waveform detected in the measurement step;
A three-dimensional virtual space corresponding to the shape of the object obtained from the measurement step and the peak detection step is created, and the virtual space is divided into a length direction X, a width direction Y, and a thickness direction of the object. A peak that is divided into Z and forms a large number of regions, the positions of the plurality of peaks obtained in the peak detection step are respectively assigned to the regions, and the number of peaks is integrated for each region. A distribution process;
A grouping step of connecting the continuous regions in which the number of peaks is integrated to form a plurality of groups;
A region forming the discontinuous group is separated from a region forming the group formed in the grouping step and continuous in the length direction X, the width direction Y, and the thickness direction Z of the object. , possess a thickness calculating step of obtaining the thickness of the object,
Among the plurality of groups formed in the grouping step, select two groups having a large total value of the number of all the peaks in the region constituting each group, and the thickness of the object A method for measuring thickness by ultrasonic waves, characterized in that a smaller position in the direction Z is a B1 echo group, a larger one is a B2 echo group, and the two groups are the continuous groups in the thickness calculation step. .
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