JP2004325229A - Method for inspecting abnormal sound - Google Patents

Method for inspecting abnormal sound Download PDF

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Publication number
JP2004325229A
JP2004325229A JP2003119904A JP2003119904A JP2004325229A JP 2004325229 A JP2004325229 A JP 2004325229A JP 2003119904 A JP2003119904 A JP 2003119904A JP 2003119904 A JP2003119904 A JP 2003119904A JP 2004325229 A JP2004325229 A JP 2004325229A
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Japan
Prior art keywords
abnormal
abnormal sound
sound
abnormal noise
pressure data
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JP2003119904A
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JP3861849B2 (en
Inventor
Takashi Anmen
隆史 安面
Takashi Murozaki
隆 室崎
Koji Yamaguchi
浩二 山口
Sadaki Kondo
禎樹 近藤
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Denso Corp
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Denso Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To provide an method for inspecting abnormal sounds capable of analyzing whether abnormal sound generated from an object to be inspected at reciprocating movements is abnormal sound due to flaws, adhering matter, etc. <P>SOLUTION: In the abnormal sound inspection method, the object to be inspected (1) is reciprocated, and operating sound from the object to be inspected is measured to acquire time-series sound pressure data (300). Abnormal sound regions (S<SB>1</SB>-S<SB>3</SB>) at which abnormal sound has occurred is detected on the basis of the time-series sound pressure data. It is determined whether the abnormal sound regions have occurred symmetrically to a return point as a center or not. Through the use of sound pressure data on the abnormal sound regions which have occurred symmetrically to the return point of reciprocating movements as a center, frequency analysis is performed. Since abnormal sound due to noise which occurs in random order is excluded, and frequency analysis is performed only on data on abnormal sound clearly due to flaws, adhering matter, etc. by using the principle that abnormal sound due to flaws, adhering matter, etc. occur symmetrically to the return point of reciprocating movements as a center, it is possible to highly accurately detect the abnormal sound. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【0001】
【発明の属する技術分野】
本発明は異音検査方法に関し、特に往復動作時に検査対象物から発生する異音が、傷又は付着物等による異音であるか否かを判定することが可能な異音検査方法に関する。
【0002】
【従来の技術】
フィルムシャッタのように、往復動作を行い、傷又は付着物によって動作時に異音が出現する製品の検査では、異音の出現するタイミングが検出できないため、異音による不良品検査を自動化することが困難であった。そこで、検査担当者がヘッドフォン等を用いて検査対象物の動作音を聞いて、人間の耳によって傷又は付着物による異音か否かを判断せざるを得なかった。
【0003】
また、周波数毎のパワースペクトルを用いて異音の検査を行う方法も提案されている。
【0004】
【発明が解決しようとする課題】
しかしながら、検査対象物は多品種少量生産のものが多く、品種ごとの異音に対応する周波数毎のパワースペクトルを特定することも容易ではなかった。さらに、検査対象物から検出した全ての異音について、詳細な検査を行うことは、演算処理による負担が大きく実用的ではなかった。
【0005】
そこで、本発明は、往復動作時に検査対象物から発生する異音が、傷又は付着物等による異音であるか否かを判定することが可能な異音検査方法を提供することを目的とする。
【0006】
また、本発明は、傷又は付着物等による異音である判然性が高いデータについてのみ周波数解析を行うことが可能な異音検査方法を提供することを目的とする。
【0007】
さらに、本発明は、往復動作時に検査対象物から発生する異音によって、検査対象物が良品か不良品かを判断することが可能な異音検査方法を提供することを目的とする。
【0008】
【課題を解決するための手段】
上記の目的を達成するために、本発明に係る異音検出方法では、検査対象物を往復動作させ、検査対象物からの動作音を測定して時系列音圧データを求め、時系列音圧データから異音の発生している異音領域を検出し、異音領域が往復動作の折り返し点を中心にして対称に出現しているか否かを判定して、往復動作の折り返し点を中心にして対称に出現している異音領域における音圧データを用いて周波数解析を行うことを特徴とする。傷又は付着物等による異音は、往復動作の折り返し点を中心に対称に出現するという原理を用いて、ランダムに発生するノイズによる異音を排除し、傷又は付着物等による異音である判然性が高いデータについてのみ周波数解析を行うので、高精度な異音検出を行うことが可能となった。
【0009】
また、本発明に係る異音検出方法では、異音領域が往復動作の折り返し点を中心にして対称に出現しているか否かの判定は、検査対象物の往路動作中でのみ行うことが好ましい。検査対象物の往復動作開始から折り返し点までについて判定すれば十分であるので、処理データ量及び検査時間を短縮することが可能となる。
【0010】
さらに、本発明に係る異音検出方法では、出現した異音領域の個数を計数し、出現した異音領域の個数が2より少ない場合は、異音なしと判定することが好ましい。異音領域が1又は0の場合には、異音領域が往復動作の折り返し点を中心にして対称に出現していることは無いので、処理データ量及び検査時間を短縮することが可能となる。
【0011】
【発明の実施の形態】
以下、本発明に係る異音検出方法を添付図面を用いて詳述する。
【0012】
最初に、異音検査方法の原理について説明する。往復動作を行う検査対象物に傷又は付着物による異音が出現する場合、傷又は付着物の位置は変化しないため、往復動作の折り返し点を中心にして対称に異音が出現することとなる。したがって、折り返し点を中心に対称に出現している異音のみを傷又は付着物等による異音と判定することができる。逆に、折り返し点を中心に対称に出現していない異音は、ランダムに発生するノイズ等によるものと判断することができる。
【0013】
しかしながら、たまたま、折り返し点を中心に対称にノイズによる異音が発生する場合もあるので、折り返し点を中心に対称に発生した異音の周波数解析を行って、傷又は付着物等による異音かノイズによる異音かをさらに判定する。なお、周波数解析を測定した全ての音圧データについて行うこともできるが、演算処理による負担が大きくなるので、折り返し点を中心に対称に出現している異音領域のみについて周波数解析を行うことが実用的である。
【0014】
そこで、本発明に係る異音検査方法では、最初に、異音と考えることができる音圧レベルを閾値と定め、検査対象物を往復動作させて時系列的に音圧レベルを測定し、その閾値を超える異音が出現している異音領域を検出する。次に、異音領域が検査対象物の往復動作における折り返し点を中心にして対称に出現しているかどうかを判定する。次に、折り返し点を中心に対称に出現している異音領域についてのみ周波数解析を行い、周波数解析の結果を利用して、傷又は付着物等による異音か否かの判定をさらに行う。
【0015】
図1は、異音検査方法を実施するためのシステムの概要を示す図である。検査対象物であるフィルムシャッタ1の近傍に音圧検出用のマイク10が配置され、マイク10からの音圧信号は、アンプ20、所定のアナログフィルタ30を経てA/D変換回路40でサンプリングされて音圧レベルを示すデジタル信号である音圧データとしてパーソナルコンピュータ(PC)50に入力される。
【0016】
PC50は、CPU等から構成される制御部51、I/O52、音圧データ等を記憶するためのメモリ53、表示部54及びキーボード及びマウス等の操作部55等から構成される。ここで、音圧レベルを示すデジタル信号としてPC50に入力された音圧データは、所定のメモリ53に記憶され、後述する異音検査方法に従って、解析される。
【0017】
フィルムシャッタ1は、サーボモータ(図示せず)によって往復動作可能に取り付けられており、PC50からのスタート信号(時刻T)によってサーボモータが動作して、フィルムシャッタ1は往路動作(速度V)を開始し、PC50からの所定の反転信号(時刻T)で復路動作(速度V)に移行して、所定時間経過後にフィルムシャッタ1の移動が停止される(時刻T)。
【0018】
図2に、異音検査方法の手順を示す。図2に示す手順は、PC50の制御部51又はメモリ53に記憶された所定のプログラムにしたがって、PC50の制御部51等によって実行される。
【0019】
最初に、PC50のメモリ53に記憶されている音圧データから、予め定められた閾値Sを用いて異音領域を検出して、PC50のメモリ53に記憶する(ステップ201)。図3(a)にPC50に記憶されている音声データ300と、閾値S301の例を示す。図3(a)の縦軸Sは音圧レベル(電圧)、横軸Tはスタート時(T)からのサーボモータの動作時間を示している。異音領域は、閾値Sを越える連続した時間領域を言う。
【0020】
次に、検出された各異音領域の動作時間を検出して、PC50のメモリ53に記憶する(ステップ202)。図3(a)の場合における、検出された異音領域S〜S及びそれぞれの動作時間T〜Tを図3(b)に示す。動作時間T〜Tは、各異音領域S〜Sの中心値とする。動作時間T〜Tは、サーボモータのスタート時間(T)を基準にして求められる。したがって、Tは、T1aとT1bとの中心値、Tは、T2aとT2bとの中心値、及びTはT3aとT3bとの中心値となる。
【0021】
次に、異音領域の個数(n)が計数される(ステップ203)。図3の場合、n=3となる。
【0022】
次に、異音領域の個数(n)が2以上か否かが判断され(ステップ204)、2以上の場合には、X=1とされる(ステップ205)。nが1又は0の場合は、ステップ211へ進み、検査対象物は良品であると判断されて、検査を終了する。n=0の時は、異音領域が出現していないということであるから、検査対象物は良品であると判断できる。また、n=1の時は、少なくとも折り返し点を中心にして対称に出現している異音領域は無いので、検査対象物は良品であると判断できる。
【0023】
次に、異音領域の1つ(S)が折り返し点を中心にして対称に出現しているか否かを判断する(ステップ206)。折り返し点を中心にして対称に出現している場合には、ステップ207へ進み、周波数解析を行う。また、異音領域(S)が、折り返し点を中心にして対称に出現していない場合には、ステップ209に進んでX=X+1とされる。
【0024】
ステップ207の周波数解析の結果、異音領域の周波数が所定範囲内か否かの判定がなされ(ステップ208)、所定範囲内であると判定されると、該等する異音領域は傷又は付着物による異音であると判定され、ステップ212へ進んで、検査対象物は不良品であると判断されて一連の検査を終了する。また、所定の範囲内ではないと判定されると、該等する異音領域は傷又は付着物による異音でないと判定されて、ステップ209へ進む。
【0025】
次に、次の異音領域の動作時間(T)が折り返し点の時刻Tより大きいか否かが判断される(ステップ210)。異音領域が折り返し点を中心に対称に出現しているか否かは、T〜Tの動作時間内で判断すれば十分であるので、T>Tと判断された場合には、検査手順を終了するようにしたものである。したがって、T>Tの場合には、ステップ211へ進み、検査対象物は良品であると判断されて検査を終了する。そうでない場合には、再度ステップ206〜210を繰り返す。
【0026】
ここで、ステップ206における異音領域が折り返し点を中心に対称に出現しているか否かの判定方法の一例について説明する。T〜T間(往路動作)における検査対象物の速度をV、T〜T間(復路動作)における検査対象物の速度をVとする。T〜T間の異音領域Sの動作時間をTとして、折り返し点時刻Tを中心にして対称に異音領域Sが出現しているとするとその動作時間Tは、以下の式で表される。
【0027】
=−V/V・T+(V+V)/V・T
したがって、Tを計算で求め、Tに相当する動作時間を有する異音領域SがT〜T間(復路動作)に存在するか否かを、メモリ53に記憶されているT〜T間の異音領域の動作時間とTとを比較することにより判定すればよい。
【0028】
次に、ステップ207及び208における周波数解析法の一例について説明する。PC50のメモリ53に記憶された音圧データの内、ステップ206で折り返し点Tを中心に対象に出現している異音領域内の音声データのみに関してパワースペクトルを求め、最大パワースペクトルを有する周波数を、その周波数とする。求められた周波数が所定の範囲(例えば、300Hz〜1KHz)に存在する場合には、傷又は付着物による異音と判定し、所定の範囲以外の周波数である場合には、ノイズによる異音であると判定する。
【0029】
図2に示す手順を用いて検査した場合、図3(a)に示す音圧データ300の場合、異音領域Sは折り返し点時刻Tを中心にして対称の位置Sに異音領域が無いと判定され、周波数解析は行われない。しかし、異音領域Sは折り返し点時刻Tを中心にして対称の位置に異音領域Sがあるので、次の周波数解析のステップへ進む。周波数解析の結果図3(c)のように、異音領域S及びS間の音圧データが有する周波数は、いずれも所定範囲(H〜H)内にあるので、異音領域S及びSは、傷又は付着物による異音であると判定され、音圧データ300が測定された検査対象物は不良品と判断される。
【0030】
また、図4に別の音圧データ400の例を示す。図4(a)に示すように、最初に閾値Sを用いて、異音領域S〜S及びそれぞれの動作時間T〜Tが検出される(図4(b)参照)。しかしながら、異音領域Sは、折り返し点Tを中心にして対称に出現していないので、異音領域Sについて周波数解析は行われない。しかしながら、異音領域SとSは、折り返し点Tを中心にして対称に出現しているので、異音領域SとSの音圧データについて周波数解析が行われる。周波数解析の結果、異音領域SとS間の音圧データが有する周波数は、いずれも所定範囲(H〜H)内には無いので(図4(c)参照)、異音領域S及びSは、傷又は付着物による異音ではないと判定され、音圧データ400が測定された検査対象物は良品と判断される。
【0031】
なお、T、V及びVの値は、検査対象物を往復動作させるサーボモータの駆動信号等から得ることができる。また、記憶されている各異音領域の動作時間とTを比較する場合には、多少の余裕度(例えば、±0.1s等)を持たせることが好ましい。
【0032】
また、図2の検査手順では、異音領域について順次判定を行い、最初に折り返し点時刻Tを中心にして対称の異音領域が出現していると判定されると、それ以降の異音領域に関する判定がなされずに、その時点で不良品と判断されてしまうが、T〜T間に存在する全ての異音領域について折り返し点時刻Tを中心にして対称の異音領域が出現しているか否かを判定するようにしても良い。
【0033】
さらに、図2の検査手順では、T〜T間のみに存在する異音領域について折り返し点時刻Tを中心にして対称の異音領域があるか否かを判定しているが、全ての動作時間(T〜T間)に存在する全ての異音領域について同様の判定を行うようにしても良い。
【0034】
さらに、図2の検査手順では、折り返し点時刻Tを中心にして対称に出現している異音領域の両方について周波数解析を行っているが、一方のみについて周波数解析を行うようにしても良い。
【図面の簡単な説明】
【図1】本発明に係わる異音検査方法を実施するためのシステムの概要を示す図である。
【図2】本発明に係わる異音検査方法の手順を示す図である。
【図3】(a)は測定データの一例を示し、(b)は(a)の場合の異音領域の例を示し、(c)は(b)に示す異音領域の周波数解析結果を示す図である。
【図4】(a)は測定データの他の例を示し、(b)は(a)の場合の異音領域の例を示し、(c)は(b)に示す異音領域の周波数解析結果を示す図である。
【符号の説明】
1…検査対象物
20…アンプ
30…フィルタ
40…A/D変換器
50…PC
〜S…異音領域
〜T…異音領域の動作時間
[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an abnormal noise inspection method, and more particularly to an abnormal noise inspection method capable of determining whether an abnormal noise generated from an inspection object during a reciprocating operation is an abnormal noise due to a scratch, an attached matter, or the like.
[0002]
[Prior art]
In the inspection of products that perform reciprocating motion, such as a film shutter, and generate abnormal noise during operation due to scratches or deposits, it is not possible to detect the timing of the occurrence of abnormal noise, so it is possible to automate defective product inspection due to abnormal noise. It was difficult. Therefore, the person in charge of the inspection must listen to the operation sound of the inspection object using headphones or the like and judge whether or not the sound is abnormal due to a scratch or an attached matter with the human ear.
[0003]
Further, a method of performing an abnormal sound inspection using a power spectrum for each frequency has also been proposed.
[0004]
[Problems to be solved by the invention]
However, many test objects are produced in small lots of various types, and it is not easy to specify a power spectrum for each frequency corresponding to abnormal noise for each type. Further, it is not practical to perform a detailed inspection on all abnormal sounds detected from the inspection object because of a heavy burden of arithmetic processing.
[0005]
Therefore, an object of the present invention is to provide an abnormal noise inspection method capable of determining whether or not an abnormal noise generated from an inspection object during a reciprocating operation is an abnormal noise due to a scratch, a deposit, or the like. I do.
[0006]
It is another object of the present invention to provide an abnormal noise inspection method capable of performing frequency analysis only on data having high obviousness, which is an abnormal noise due to a scratch, a deposit, or the like.
[0007]
Still another object of the present invention is to provide an abnormal noise inspection method capable of determining whether a test object is a non-defective product or a defective product based on abnormal noise generated from the test object during a reciprocating operation.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, in the abnormal sound detection method according to the present invention, the test object is reciprocated, the operation sound from the test object is measured to obtain time-series sound pressure data, and the time-series sound pressure Detect the abnormal sound area where abnormal noise is generated from the data, judge whether the abnormal sound area appears symmetrically around the turning point of the reciprocating operation, and determine the abnormal sound area around the turning point of the reciprocating operation. Frequency analysis is performed using sound pressure data in an abnormal sound region appearing symmetrically. Abnormal noise due to scratches or extraneous matter is an abnormal noise due to scratches or extraneous matter, etc., using the principle that it appears symmetrically around the turning point of reciprocation, eliminating noise due to randomly generated noise. Since frequency analysis is performed only on data having high obviousness, it has become possible to detect abnormal noise with high accuracy.
[0009]
In the abnormal sound detection method according to the present invention, it is preferable that the determination as to whether or not the abnormal sound region appears symmetrically around the turning point of the reciprocating operation is performed only during the outward movement of the inspection object. . Since it is sufficient to make a determination from the start of the reciprocating operation of the inspection object to the turning point, it is possible to reduce the processing data amount and the inspection time.
[0010]
Further, in the abnormal sound detection method according to the present invention, it is preferable to count the number of abnormal noise regions that appear, and determine that there is no abnormal noise when the number of abnormal noise regions that appear is less than two. When the abnormal sound area is 1 or 0, since the abnormal sound area does not appear symmetrically around the turning point of the reciprocating operation, the processing data amount and the inspection time can be reduced. .
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the abnormal sound detection method according to the present invention will be described in detail with reference to the accompanying drawings.
[0012]
First, the principle of the abnormal noise inspection method will be described. When an abnormal sound due to a flaw or an adhering substance appears on the inspection object performing the reciprocating operation, the position of the flaw or the adhering substance does not change, so that an abnormal noise appears around the turning point of the reciprocating operation. . Therefore, it is possible to determine only an abnormal noise that appears symmetrically around the turning point as an abnormal noise due to a scratch, a deposit, or the like. Conversely, abnormal noise that does not appear symmetrically around the turning point can be determined to be due to randomly generated noise or the like.
[0013]
However, there is a case where abnormal noise due to noise occurs symmetrically around the turning point.Therefore, the frequency analysis of the abnormal noise generated symmetrically around the turning point is performed, It is further determined whether the noise is abnormal. It should be noted that the frequency analysis can be performed on all measured sound pressure data.However, since the burden of the arithmetic processing becomes large, it is possible to perform the frequency analysis only on the abnormal sound region that appears symmetrically around the turning point. It is practical.
[0014]
Therefore, in the abnormal sound inspection method according to the present invention, first, a sound pressure level that can be considered as an abnormal sound is set as a threshold, and the sound pressure level is measured in time series by reciprocating the inspection object. An abnormal sound area where an abnormal sound exceeding a threshold appears is detected. Next, it is determined whether or not the abnormal sound area appears symmetrically around the turning point in the reciprocating operation of the inspection object. Next, the frequency analysis is performed only on the abnormal sound region that appears symmetrically around the turning point, and the result of the frequency analysis is further used to determine whether or not the abnormal sound is caused by a flaw, a deposit, or the like.
[0015]
FIG. 1 is a diagram showing an outline of a system for implementing the abnormal noise inspection method. A microphone 10 for detecting sound pressure is arranged near the film shutter 1 to be inspected, and a sound pressure signal from the microphone 10 is sampled by an A / D conversion circuit 40 through an amplifier 20 and a predetermined analog filter 30. Input to a personal computer (PC) 50 as sound pressure data which is a digital signal indicating the sound pressure level.
[0016]
The PC 50 includes a control unit 51 including a CPU, an I / O 52, a memory 53 for storing sound pressure data and the like, a display unit 54, and an operation unit 55 such as a keyboard and a mouse. Here, the sound pressure data input to the PC 50 as a digital signal indicating the sound pressure level is stored in a predetermined memory 53 and analyzed according to the abnormal sound inspection method described later.
[0017]
The film shutter 1 is mounted so as to be capable of reciprocating operation by a servo motor (not shown). The servo motor operates according to a start signal (time T S ) from the PC 50, and the film shutter 1 performs an outward movement (speed V 1). ) Is started, and a transition is made to a return path operation (speed V 2 ) by a predetermined inversion signal (time T C ) from the PC 50, and the movement of the film shutter 1 is stopped after a predetermined time has elapsed (time T F ).
[0018]
FIG. 2 shows the procedure of the abnormal noise inspection method. The procedure shown in FIG. 2 is executed by the control unit 51 of the PC 50 or the like according to a predetermined program stored in the control unit 51 of the PC 50 or the memory 53.
[0019]
First, from the sound pressure data stored in the memory 53 of the PC 50, to detect the abnormal sound area using a threshold S R which is determined in advance, and stored in the memory 53 of the PC 50 (step 201). Audio data 300 stored in PC50 in FIG. 3 (a), showing an example of a threshold value S R 301. Figure 3 the vertical axis S is sound pressure level (a) (voltage), horizontal axis T indicates the operation time of the servo motor from the start (T S). Abnormal noise region refers to continuous time domain exceeding the threshold value S R.
[0020]
Next, the operation time of each detected abnormal sound area is detected and stored in the memory 53 of the PC 50 (Step 202). FIG. 3B shows the detected abnormal sound regions S 1 to S 3 and the respective operation times T 1 to T 3 in the case of FIG. The operation times T 1 to T 3 are the center values of the abnormal sound areas S 1 to S 3 . Operation time T 1 through T 3 is determined based on the start time of the servo motor (T S). Therefore, T 1 is the center value between T 1a and T 1b , T 2 is the center value between T 2a and T 2b , and T 3 is the center value between T 3a and T 3b .
[0021]
Next, the number (n) of the abnormal sound areas is counted (step 203). In the case of FIG. 3, n = 3.
[0022]
Next, it is determined whether or not the number (n) of the abnormal sound areas is 2 or more (step 204). If it is 2 or more, X = 1 is set (step 205). If n is 1 or 0, the process proceeds to step 211, where the inspection object is determined to be non-defective, and the inspection ends. When n = 0, it means that the abnormal sound area has not appeared, so that it can be determined that the inspection object is a good product. When n = 1, there is no abnormal sound area symmetrically appearing at least around the turning point, so that the inspection object can be determined to be good.
[0023]
Next, it is determined whether or not one of the abnormal sound areas (S X ) appears symmetrically around the turning point (step 206). If it appears symmetrically around the turning point, the process proceeds to step 207 to perform frequency analysis. If the abnormal sound area (S X ) does not appear symmetrically around the turning point, the process proceeds to step 209, where X = X + 1.
[0024]
As a result of the frequency analysis in step 207, it is determined whether or not the frequency of the abnormal sound area is within a predetermined range (step 208). It is determined that the noise is caused by the kimono, and the process proceeds to step 212, where the inspection object is determined to be defective, and a series of inspections is completed. If it is determined that the noise is not within the predetermined range, it is determined that the equal noise area is not an abnormal noise due to a scratch or an attached matter, and the process proceeds to step 209.
[0025]
Next, the operation time of the next abnormal noise region (T X) whether greater than the time T C of the turning point is determined (step 210). It is sufficient to judge whether or not the abnormal sound area appears symmetrically around the turning point within the operation time from T S to T C. Therefore, when it is determined that T X > T C , This is to terminate the inspection procedure. Therefore, in the case of T X> T C, the process proceeds to step 211, the inspection object to end the inspection is determined as non-defective. Otherwise, steps 206 to 210 are repeated again.
[0026]
Here, an example of a method of determining whether or not the abnormal sound area appears symmetrically around the turning point in step 206 will be described. The speed of the inspection object between T S and T C (forward operation) is V 1 , and the speed of the inspection object between T C and TF (return operation) is V 2 . The T S through T operation time of noise area S X between C as T X, when the symmetrically around a turning point time T C is abnormal sound area S Y have appeared the operation time T Y is It is represented by the following equation.
[0027]
T Y = −V 1 / V 2 · T X + (V 1 + V 2 ) / V 2 · T C
Therefore, T Y is obtained by calculation, and whether or not an abnormal sound area S Y having an operation time corresponding to T Y exists between T C and TF (return operation) is stored in T 53 stored in the memory 53. it may be determined by comparing the operating time of noise region between C through T F and T Y.
[0028]
Next, an example of the frequency analysis method in steps 207 and 208 will be described. Among the sound pressure data stored in the memory 53 of the PC 50, seek a power spectrum with respect to only the audio data of noise in the area that appears in the subject around the turning point T C in step 206, a frequency having a maximum power spectrum Is the frequency. If the obtained frequency is within a predetermined range (for example, 300 Hz to 1 KHz), it is determined that the noise is due to a scratch or an adhering substance. It is determined that there is.
[0029]
When examined using the procedure shown in FIG. 2, abnormal noise region in Figure 3 when the sound pressure data 300 (a), the abnormal noise region S 1 is located S 4 symmetrically about the turning point time T C Is determined to be absent, and no frequency analysis is performed. However, abnormal noise region S 2 is so positioned symmetrically about the turning point time T C is abnormal sound area S 3, the process proceeds to the next step of the frequency analysis. As a result Figure 3 of a frequency analysis (c), the frequency having the sound pressure data between abnormal noise region S 2 and S 3 since they are in a predetermined range (H 1 ~H 2) within, abnormal noise region S 2 and S 3 is determined to be abnormal sound due to a scratch or deposits the inspection object sound pressure data 300 is measured is determined to be defective.
[0030]
FIG. 4 shows another example of the sound pressure data 400. As shown in FIG. 4 (a), first using the threshold S R, abnormal noise region S 5 to S 7 and each operation time T 5 through T 7 is detected (see Figure 4 (b)). However, abnormal noise region S 5, since not appear symmetrically around a turning point T C, frequency analysis for abnormal noise region S 5 is not performed. However, abnormal sound region S 6 and S 7, since around the turn point T C have appeared symmetrical, frequency analysis is performed for the sound pressure data of the abnormal sound area S 6 and S 7. Result of the frequency analysis, the frequency that has the sound pressure data between abnormal sound region S 6 and S 7, since both not in a predetermined range (H 1 to H 2) (refer FIG. 4 (c)), abnormal noise area S 6 and S 7 are determined not to be abnormal noise due to a scratch or deposits the inspection object sound pressure data 400 is measured is determined to be nondefective.
[0031]
The values of T C , V 1, and V 2 can be obtained from a drive signal of a servomotor that reciprocates the inspection object. Furthermore, when comparing the operation time and T Y of respective abnormal noise region stored is some margin (e.g., ± 0.1s, etc.) is preferably formed to have a.
[0032]
Further, the testing procedure of FIG. 2 performs a sequential determination for abnormal noise region, the first time around the turn point time T C symmetry of noise region is determined to have emerged, subsequent allophone without a determination is made regarding areas, but would be determined at that time to be defective, all the abnormal noise region symmetry of noise regions around the turning point time T C for the existing between T S through T C is It may be determined whether or not it has appeared.
[0033]
Furthermore, in the inspection procedure of FIG. 2, but around the turn point time T C is determined whether there is abnormal noise region symmetrical about the abnormal noise region present only between T S through T C, all it may perform similar determination for all the abnormal noise region existing operating time (between T S ~T F).
[0034]
Furthermore, in the inspection procedure of FIG. 2, is performed frequency analysis for both the abnormal noise regions around the turning point time T C have appeared symmetrical, it may be performed frequency analysis on only one .
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of a system for implementing an abnormal noise inspection method according to the present invention.
FIG. 2 is a diagram showing a procedure of an abnormal noise inspection method according to the present invention.
3A shows an example of measured data, FIG. 3B shows an example of an abnormal sound area in the case of FIG. 3A, and FIG. 3C shows a frequency analysis result of the abnormal sound area shown in FIG. FIG.
4A shows another example of the measurement data, FIG. 4B shows an example of an abnormal sound area in the case of FIG. 4A, and FIG. 4C shows a frequency analysis of the abnormal sound area shown in FIG. It is a figure showing a result.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Test object 20 ... Amplifier 30 ... Filter 40 ... A / D converter 50 ... PC
S 1 ~S 3 ... noise area T 1 ~T 3 ... the operating time of the noise area

Claims (6)

検査対象物を往復動作させ、前記検査対象物からの動作音を測定して時系列音圧データを求める工程と、
前記時系列音圧データから異音の発生している異音領域を検出する工程と、
前記異音領域が往復動作の折り返し点を中心にして対称に出現しているか否かを判定する工程と、
往復動作の折り返し点を中心にして対称に出現している異音領域における音圧データを用いて周波数解析を行う工程とを有することを特徴とする異音検査方法。
Reciprocating the inspection object, measuring the operation sound from the inspection object to obtain time-series sound pressure data,
A step of detecting an abnormal sound area where abnormal sound has occurred from the time-series sound pressure data;
A step of determining whether or not the abnormal sound area appears symmetrically around the turning point of the reciprocating operation;
Performing a frequency analysis using sound pressure data in an abnormal sound region appearing symmetrically around a turning point of the reciprocating operation.
前記周波数解析工程は、往復動作の折り返し点を中心にして対称に出現している異音領域における音圧データの周波数を求め、求められた周波数が所定の周波数範囲に入るか否かを判断する請求項1に記載の異音検査方法。In the frequency analysis step, the frequency of the sound pressure data in the abnormal sound region appearing symmetrically around the turning point of the reciprocating operation is determined, and it is determined whether the determined frequency falls within a predetermined frequency range. The abnormal noise inspection method according to claim 1. さらに、前記周波数解析工程の結果に応じて、前記検査対象物が不良品であるか否かを判断する請求項1又は2に記載の異音検査方法。The abnormal noise inspection method according to claim 1, further comprising determining whether or not the inspection object is defective based on a result of the frequency analysis step. 前記異音領域が往復動作の折り返し点を中心にして対称に出現しているか否かの判定工程は、前記検査対象物の往路動作中で検出された異音領域のみについて行われる請求項1〜3の何れか一項に記載の異音判定方法。The step of determining whether or not the abnormal sound area appears symmetrically around the turning point of the reciprocating operation is performed only for the abnormal sound area detected during the outward movement of the inspection object. 3. The method for determining abnormal noise according to any one of 3. さらに、出現した異音領域の個数を計数する工程を有する請求項1〜4の何れか一項に記載の異音判定方法。The abnormal noise determination method according to any one of claims 1 to 4, further comprising a step of counting the number of appearing abnormal noise regions. さらに、前記出現した異音領域の個数が2より少ない場合、前記検査対象物は良品であると判断する工程とを有する請求項1〜5の何れか一項に記載の異音判定方法。The method according to any one of claims 1 to 5, further comprising the step of: determining that the inspection object is a non-defective product when the number of the appearing abnormal sound areas is smaller than two.
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6456574B1 (en) * 2018-04-04 2019-01-23 三菱電機株式会社 Diagnostic device, sensor data collecting device, diagnostic method, diagnostic program, and diagnostic system
CN114999537A (en) * 2022-06-22 2022-09-02 歌尔科技有限公司 Abnormal sound signal detection method, device and equipment and readable storage medium
JPWO2022219711A1 (en) * 2021-04-13 2022-10-20

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6456574B1 (en) * 2018-04-04 2019-01-23 三菱電機株式会社 Diagnostic device, sensor data collecting device, diagnostic method, diagnostic program, and diagnostic system
WO2019193682A1 (en) * 2018-04-04 2019-10-10 三菱電機株式会社 Diagnostic device, sensor data collection apparatus, diagnostic method, diagnostic program, and diagnostic system
JPWO2022219711A1 (en) * 2021-04-13 2022-10-20
JP7322975B2 (en) 2021-04-13 2023-08-08 日本精工株式会社 Condition monitoring device and condition monitoring method for linear guide
CN114999537A (en) * 2022-06-22 2022-09-02 歌尔科技有限公司 Abnormal sound signal detection method, device and equipment and readable storage medium

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