JPH09243480A - Apparatus for estimating excitation force - Google Patents
Apparatus for estimating excitation forceInfo
- Publication number
- JPH09243480A JPH09243480A JP5188396A JP5188396A JPH09243480A JP H09243480 A JPH09243480 A JP H09243480A JP 5188396 A JP5188396 A JP 5188396A JP 5188396 A JP5188396 A JP 5188396A JP H09243480 A JPH09243480 A JP H09243480A
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- Prior art keywords
- response
- excitation force
- acceleration
- response function
- function
- Prior art date
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- Force Measurement Appropriate To Specific Purposes (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、例えばエンジン
等、稼働時に衝撃的励振力が作用する機器における励振
力を推定する励振力推定装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exciting force estimating apparatus for estimating an exciting force in a device, such as an engine, to which an exciting exciting force acts during operation.
【０００２】[0002]
【従来の技術】従来、例えばエンジン等、稼働時に衝撃
的励振力が作用する機器における励振力を推定する励振
力推定装置は、図１１に示すように構成されている。図
１１において、ａはインパルス応答関数計測部、ｂは機
器稼働時の振動応答計測部、ｃは励振力推定演算部で、
インパルス応答関数計測部ａで求めたインパルス応答関
数及び機器稼働時の振動応答計測部ｂで計測した機器稼
働時の振動応答を用いて、励振力推定演算部ｃで励振力
推定値を計算する。2. Description of the Related Art Conventionally, an exciting force estimating apparatus for estimating an exciting force in a device such as an engine to which an impulsive exciting force is applied during operation is constructed as shown in FIG. In FIG. 11, a is an impulse response function measurement unit, b is a vibration response measurement unit when the device is in operation, and c is an excitation force estimation calculation unit.
Using the impulse response function obtained by the impulse response function measuring unit a and the vibration response during operation of the device measured by the vibration response measuring unit b during operation of the device, an excitation force estimation calculation unit c calculates an excitation force estimation value.
【０００３】上記インパルス応答関数計測部ａにおい
て、１は構造系、つまり、被計測機器で、加振試験を行
なう際、励振力着力点Ａにインパルスハンマ２により既
知の荷重（インパルス）が加えられる。また、被測定機
器１には、振動応答測定点Ｂに加速度検出器３を設け、
上記インパルスハンマ２により荷重が加えられた際の加
速度応答（加速度信号）を検出している。上記インパル
スハンマ２の励振力及び加速度検出器３により検出した
加速度応答は、第１のメモリ装置４に記憶され、第１の
演算装置５に送られる。この第１の演算装置５は、上記
入力信号に基づいてインパルス応答関数計算を行ない、
この計算によって得られたインパルス応答関数を振動応
答計測部ｂの第２のメモリ装置６に出力する。In the impulse response function measuring section a, reference numeral 1 denotes a structural system, that is, a device to be measured, when a vibration test is performed, a known load (impulse) is applied to an excitation force application point A by an impulse hammer 2. . In addition, the device under test 1 is provided with an acceleration detector 3 at the vibration response measurement point B,
The acceleration response (acceleration signal) when a load is applied by the impulse hammer 2 is detected. The excitation force of the impulse hammer 2 and the acceleration response detected by the acceleration detector 3 are stored in the first memory device 4 and sent to the first arithmetic device 5. The first arithmetic unit 5 performs an impulse response function calculation based on the input signal,
The impulse response function obtained by this calculation is output to the second memory device 6 of the vibration response measuring section b.
【０００４】また、この第２のメモリ装置６には、被測
定機器１の稼働時における加速度応答が加速度検出器３
により検出されて記憶される。そして、第２のメモリ装
置６に記憶された機器稼働時の加速度応答及びインパル
ス応答関数は、励振力推定演算部ｃの第２の演算装置７
に入力される。The second memory device 6 stores an acceleration response during operation of the device under test 1 in the acceleration detector 3.
Is detected and stored. Then, the acceleration response and the impulse response function at the time of device operation stored in the second memory device 6 are calculated by the second calculation device 7 of the excitation force estimation calculation unit c.
Is input to
【０００５】上記の構成において、励振力推定値は次の
ようにして求められる。 （１）まず、インパルスハンマ２により被計測機器１の
励振力着力点Ａを叩き、インパルスハンマ２の励振力と
加速度検出器３により検出した加速度応答とを第１のメ
モリ装置４に一時保存し、これを第１の演算装置５にて
インパルス応答関数を計算する。[0005] In the above configuration, the excitation force estimated value is obtained as follows. (1) First, the impulse hammer 2 strikes the excitation force applied point A of the device 1 to be measured, and the excitation force of the impulse hammer 2 and the acceleration response detected by the acceleration detector 3 are temporarily stored in the first memory device 4. Then, the first arithmetic unit 5 calculates an impulse response function.
【０００６】（２）次に機器稼働時の振動応答計測部ｂ
は、被計測機器１の稼働時の加速度応答を加速度検出器
３で検出し、その計測データを第２のメモリ装置６に保
存する。(2) Next, a vibration response measuring unit b during operation of the device
Detects the acceleration response of the device under measurement 1 during operation by the acceleration detector 3 and stores the measurement data in the second memory device 6.
【０００７】（３）励振力推定演算部ｃは、第１の演算
装置５にて計算されたインパルス応答関数と振動応答計
測部ｂで計測した加速度応答の計測データとを第２の演
算装置７に入力し、周波数領域においての励振力推定計
算を行なう。(3) The excitation force estimation calculation unit c uses the impulse response function calculated by the first calculation unit 5 and the acceleration response measurement data measured by the vibration response measurement unit b as the second calculation unit 7. To calculate the excitation force estimation in the frequency domain.
【０００８】構造系の振動応答は、周波数領域では、励
振力と系の周波数応答関数の積で表されるため、機器稼
働時の振動応答スペクトルＸ（ω）（振動応答の周波数
領域における表現）を周波数応答関数Ｈ（ω）で除する
ことにより、構造系に負荷された励振力のスペクトルＦ
（ω）を求める。周波数領域で求められた励振力Ｆ
（ω）を時間領域に変換することにより、励振力の時系
列波形ｆ（ｔ）を得る。In the frequency domain, the vibration response of the structural system is represented by the product of the excitation force and the frequency response function of the system. Therefore, the vibration response spectrum X (ω) during the operation of the equipment (representation of the vibration response in the frequency domain) Is divided by the frequency response function H (ω) to obtain a spectrum F of the excitation force applied to the structural system.
Find (ω). Excitation force F obtained in frequency domain
By converting (ω) into the time domain, a time-series waveform f (t) of the excitation force is obtained.
【０００９】上記励振力推定演算部ｃは、図１２に示す
ように離散フーリエ変換器７ａ及び離散フーリエ逆変換
器７ｂにより構成されている。上記離散フーリエ変換器
７ａは、時系列データを周波数領域のデータに変換する
演算器であり、機器稼働時の振動応答及び予めインパル
ス応答関数計測部ａにて計測した振動応答測定点Ｂと励
振力着力点の間のインパルス応答関数を周波数領域のデ
ータに変換する。As shown in FIG. 12, the exciting force estimating / calculating section c is composed of a discrete Fourier transformer 7a and a discrete Fourier inverse transformer 7b. The discrete Fourier transformer 7a is an arithmetic unit that converts time-series data into frequency-domain data. The discrete Fourier transformer 7a includes a vibration response when the device is in operation, a vibration response measurement point B measured in advance by the impulse response function measurement unit a, and an excitation force. The impulse response function between the application points is converted into frequency domain data.
【００１０】また、離散フーリエ逆変換器７ｂは、周波
数領域の時系列データに変換する機能を有するものであ
る。振動応答スペクトルを周波数応答関数で除すること
により、励振力推定値スペクトルが得られるが、この励
振力推定値スペクトルに離散フーリエ逆変換器７ｂによ
る演算を施すことにより、励振力推定値を時系列として
求める。The inverse discrete Fourier transformer 7b has a function of converting the data into time-series data in the frequency domain. By dividing the vibration response spectrum by the frequency response function, an excitation force estimated value spectrum is obtained. By performing an operation by the discrete Fourier inverse transformer 7b on the excitation force estimated value spectrum, the excitation force estimated value is time-series. Asking.
【００１１】[0011]
【発明が解決しようとする課題】上記従来装置で計測し
たデータの解析例を図１３及び図１４に示す。図１３及
び図１４はハンマリング時の機器１の周波数応答関数の
例で、図１３は振幅（加速度／力）を示し、図１４は位
相（ｒａｄ）を示しているが、機器の周波数応答関数は
多数の共振点（図１３で振幅がピークを与える部分）及
び***振点（図１３では振幅が落ち込む部分）を有して
いる。従来技術を用いて周波数領域で励振力を正確に求
めるためには、これらの値を正確に計測する必要があ
る。特に***振点では、振幅値がノイズレベルまで低下
する、あるいは計測機器のダイナミックレンジの制限を
受けるなどの理由で、正確な測定が困難であることが多
い。すなわち、***振点においては、振幅がノイズある
いは計測器のダイナミックレンジの制限の影響で正しく
評価できない場合、その区間の位相値は不定となり、周
波数応答関数評価の上で大きな誤差要因となる。この誤
差を含んだ周波数応答関数を用いて励振力推定値を計算
すると、図１５に示すように推定波形にはこの評価誤差
に起因する誤差が生ずる。13 and 14 show an example of analysis of data measured by the above conventional apparatus. 13 and 14 show examples of the frequency response function of the device 1 during hammering. FIG. 13 shows the amplitude (acceleration / force) and FIG. 14 shows the phase (rad). Has a large number of resonance points (the portion where the amplitude peaks in FIG. 13) and anti-resonance points (the portion where the amplitude drops in FIG. 13). In order to accurately determine the excitation force in the frequency domain using the conventional technology, it is necessary to accurately measure these values. Particularly at the anti-resonance point, accurate measurement is often difficult because the amplitude value decreases to the noise level or the dynamic range of the measuring device is limited. That is, at the anti-resonance point, if the amplitude cannot be correctly evaluated due to the influence of noise or the limitation of the dynamic range of the measuring instrument, the phase value in that section becomes indefinite, which causes a large error in the evaluation of the frequency response function. When the excitation force estimated value is calculated using the frequency response function including this error, an error due to this evaluation error occurs in the estimated waveform as shown in FIG.
【００１２】本発明は上記の課題を解決するためになさ
れたもので、ノイズに対する安定性が強く、振幅、加振
力持続時間とも良好な推定結果が得られる励振力推定装
置を提供することを目的とする。The present invention has been made to solve the above problems, and it is an object of the present invention to provide an excitation force estimation device which has a strong stability against noise and which can obtain good estimation results in both amplitude and excitation force duration. To aim.
【００１３】[0013]
【課題を解決するための手段】本発明は、構造系の振動
応答測定点と励振力着力点との間のインパルス応答関数
を用いて構造系に負荷される励振力を推定する励振力推
定装置において、上記構造系の振動応答測定点の振動加
速度を検出する加速度検出器と、この加速度検出器によ
り検出された加速度応答及び加振試験時に上記構造系に
加えられる励振力信号を記憶する第１の記憶手段と、こ
の第１の記憶手段に記憶された加振試験時の励振力及び
加速度応答に基づいて上記構造系の振動応答測定点と励
振力着力点との間のインパルス応答関数を算出する第１
の演算手段と、この第１の演算手段により計算されたイ
ンパルス応答関数と上記加速度検出器により検出される
機器稼働時の加速度応答を記憶する第２の記憶手段と、
この第２の記憶手段に記憶されたインパルス応答関数及
び機器稼働時の加速度応答に基づいて構造系に負荷され
る励振力推定値を計算する第２の演算手段とを具備し、
上記第２の演算手段は、第２の記憶手段に記憶されたイ
ンパルス応答関数及び機器稼働時の加速度応答を周波数
領域のデータに変換する離散フーリエ変換器及び周波数
応答関数の振幅値に逆ヒルベルト変換を施して最小位相
条件を満す位相値を計算する離散ヒルベルト逆変換器か
らなる演算器と、上記周波数応答関数と応答スペクトル
との複素対数をとる複素対数変換器と、応答の対数スペ
クトルと対数周波数応答関数に離散フーリエ逆変換を施
し、複素ケプストラムに変換する離散フーリエ逆変換器
と、上記複素ケプストラムに窓関数処理を施して短いケ
フレンシのデータだけを抽出する短ケフレンシ域抽出器
と、上記窓関数処理を施した応答とインパルス応答関数
それぞれの複素ケプストラムの演算により、励振力推定
値の複素ケプストラムを求めた後、フーリエ変換により
周波数領域に変換する離散フーリエ変換器と、励振力ス
ペクトルの複素対数を真数に変換する複素指数変換器
と、上記真数に変換した励振力推定値スペクトルに離散
フーリエ逆変換を施して励振力推定値を時系列として求
める離散フーリエ逆変換器とからなることを特徴とす
る。SUMMARY OF THE INVENTION The present invention is an excitation force estimation apparatus for estimating an excitation force applied to a structural system by using an impulse response function between a vibration response measurement point of the structural system and an excitation force applying point. In an acceleration detector for detecting a vibration acceleration at a vibration response measurement point of the structural system, and an acceleration force signal detected by the acceleration detector and an exciting force signal applied to the structural system during a vibration test. And the impulse response function between the vibration response measurement point of the structural system and the excitation force applying point based on the excitation force and the acceleration response during the vibration test stored in the first storage means. First to do
And a second storage means for storing the impulse response function calculated by the first calculation means and the acceleration response during device operation detected by the acceleration detector.
A second calculation means for calculating an estimated value of the excitation force applied to the structural system based on the impulse response function stored in the second storage means and the acceleration response when the equipment is operating,
The second computing means is a discrete Fourier transformer for converting the impulse response function and the acceleration response during device operation stored in the second storage means into frequency domain data, and an inverse Hilbert transform to the amplitude value of the frequency response function. And a complex logarithmic converter that takes the complex logarithm of the frequency response function and the response spectrum, and a logarithmic spectrum and logarithm of the response. The discrete Fourier inverse transform is applied to the frequency response function, and the discrete Fourier inverse transformer that transforms it into a complex cepstrum, the short kefrenshi region extractor that applies only window data to the complex cepstrum to extract only short kefrenshi data, and the window The complex cepstrum of the excitation force estimated value is calculated by calculating the complex cepstrum of each of the response processed by the function processing and the impulse response function. After calculating the system, a discrete Fourier transformer that transforms into the frequency domain by Fourier transform, a complex exponential converter that transforms the complex logarithm of the excitation force spectrum into an antilogarithm, and an excitation force estimation value spectrum converted into the above-mentioned antilogarithm And a discrete Fourier inverse transformer that performs an inverse discrete Fourier transform to obtain an excitation force estimation value as a time series.
【００１４】（作用）加振試験時にインパルスハンマ等
を用いて構造系の励振力着力点に既知の荷重を加え、振
動応答測定点における加速度応答を加速度検出器により
検出して、加振試験における励振力及び加速度応答をメ
モリ装置に記憶する。第１の演算手段は、上記メモリ装
置に記憶した加振試験時の励振力及び加速度応答に基づ
いて構造系の振動応答測定点と励振力着力点との間のイ
ンパルス応答関数を計算する。第２の演算手段は、第１
の演算手段で計算したインパルス応答関数と上記加速度
検出器により検出される機器稼働時の加速度応答をケフ
レンシ領域のデータ（複素ケプストラム）に変換して構
造系に負荷される励振力を推定する。構造系の共振／反
共振の影響は、複素ケプストラムの長ケフレンシ領域に
現れるので、ショートパスケフレンシウィンドウ処理を
施してこれらの影響を除去する。(Operation) At the time of the vibration test, a known load is applied to the excitation force applying point of the structural system by using an impulse hammer or the like, and the acceleration response at the vibration response measurement point is detected by the acceleration detector to make the vibration test. The excitation force and acceleration response are stored in a memory device. The first calculation means calculates an impulse response function between the vibration response measurement point of the structural system and the excitation force applied point based on the excitation force and the acceleration response during the excitation test stored in the memory device. The second calculating means includes a first calculating means.
The impulse response function calculated by the calculation means and the acceleration response at the time of device operation detected by the acceleration detector are converted into data (complex cepstrum) in the quefrency region to estimate the excitation force applied to the structural system. Since the effects of the resonance / anti-resonance of the structural system appear in the long quefrency region of the complex cepstrum, short-path quefrency window processing is performed to remove these effects.
【００１５】[0015]
【発明の実施の形態】以下、図面を参照して本発明の一
実施形態を説明する。図１は、本発明の一実施形態に係
る励振力推定装置の構成を示すブロック図である。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an excitation force estimation device according to one embodiment of the present invention.
【００１６】図１において、ａはインパルス応答関数計
測部、ｂは機器稼働時の振動応答計測部、ｃは励振力推
定演算部で、インパルス応答関数計測部ａで求めたイン
パルス応答関数及び機器稼働時の振動応答計測部ｂで計
測した機器稼働時の振動応答を用いて、励振力推定演算
部ｃで励振力推定値を計算する。In FIG. 1, a is an impulse response function measuring unit, b is a vibration response measuring unit when the device is in operation, c is an exciting force estimation calculating unit, and the impulse response function and the device operation are obtained by the impulse response function measuring unit a. The excitation force estimation calculation unit c calculates an excitation force estimation value using the vibration response during device operation measured by the vibration response measurement unit b during operation.
【００１７】上記インパルス応答関数計測部ａにおい
て、１１は構造系、つまり、被計測機器で、加振試験を
行なう際、励振力着力点Ａにインパルスハンマ１２によ
り既知の荷重（インパルス）が加えられる。また、被測
定機器１１には、振動応答測定点Ｂに加速度検出器１３
を設け、上記インパルスハンマ１２により荷重が加えら
れた際の加速度応答（加速度信号）を検出している。上
記インパルスハンマ１２の励振力及び加速度検出器１３
により検出した加速度応答は、第１のメモリ装置１４に
記憶され、第１の演算装置１５に送られる。この第１の
演算装置１５は、上記入力信号に基づいてインパルス応
答関数計算を行ない、この計算によって得られたインパ
ルス応答関数を第２のメモリ装置１６に出力する。In the impulse response function measuring section a, 11 is a structural system, that is, a device to be measured, and a known load (impulse) is applied by the impulse hammer 12 to the excitation force applying force point A when performing a vibration test. . The device under test 11 has an acceleration detector 13 at the vibration response measurement point B.
And an acceleration response (acceleration signal) when a load is applied by the impulse hammer 12 is detected. Exciting force and acceleration detector 13 of the impulse hammer 12
Is stored in the first memory device 14 and sent to the first arithmetic device 15. The first arithmetic unit 15 performs impulse response function calculation based on the input signal, and outputs the impulse response function obtained by this calculation to the second memory unit 16.
【００１８】また、この第２のメモリ装置１６には、被
測定機器１１の稼働時における加速度応答が加速度検出
器１３により検出されて記憶される。そして、第２のメ
モリ装置１６に記憶された機器稼働時の加速度応答及び
インパルス応答関数は、第２の演算装置１７に入力され
る。この第２の演算装置１７は、従来の第２の演算装置
７に複素ケプストラム演算並びにショートパスケフレン
シウィンドウ処理を施す演算機能を付加したものであ
る。The acceleration response of the device under test 11 during operation is detected by the acceleration detector 13 and stored in the second memory device 16. Then, the acceleration response and the impulse response function at the time of operating the device, which are stored in the second memory device 16, are input to the second arithmetic device 17. The second arithmetic device 17 is obtained by adding a complex cepstrum arithmetic operation and an arithmetic function for performing a short path Kefrency window process to the conventional second arithmetic device 7.
【００１９】第２の演算装置１７は、図２に示すように
演算器２１、複素対数変換器２２、離散フーリエ逆変換
器２３、短ケフレンシ域抽出器２４、離散フーリエ変換
器２５、複素指数変換器２６、離散フーリエ逆変換器２
７からなっている。As shown in FIG. 2, the second arithmetic unit 17 includes an arithmetic unit 21, a complex logarithmic converter 22, a discrete Fourier inverse transformer 23, a short Kefrenshi area extractor 24, a discrete Fourier transformer 25, and a complex exponential transform. 26, discrete Fourier inverse transformer 2
It consists of seven.
【００２０】更に、上記演算器２１は、図３に示すよう
に離散フーリエ変換器２１ａ及び離散ヒルベルト逆変換
器２１ｂからなっている。次に上記実施形態の動作を説
明する。Further, the arithmetic unit 21 comprises a discrete Fourier transformer 21a and a discrete Hilbert inverse transformer 21b as shown in FIG. Next, the operation of the above embodiment will be described.
【００２１】まず、インパルスハンマ１２により被計測
機器１１の励振力着力点Ａを叩き、インパルスハンマ１
２の励振力と加速度検出器３により検出した加速度応答
とを第１のメモリ装置１４に一時保存し、これを第１の
演算装置１５にてインパルス応答関数を計算する。First, the impulse hammer 12 strikes the excitation force force applying point A of the device under test 11 and the impulse hammer 1
The excitation force 2 and the acceleration response detected by the acceleration detector 3 are temporarily stored in the first memory device 14, and the first arithmetic unit 15 calculates the impulse response function.
【００２２】次に機器稼働時の振動応答計測部ｂは、被
計測機器１１の稼働時の加速度応答を加速度検出器１３
で検出し、その計測データを第２のメモリ装置１６に保
存する。Next, the vibration response measuring section b when the equipment is in operation determines the acceleration response when the equipment under measurement 11 is in operation by the acceleration detector 13.
And the measurement data is stored in the second memory device 16.
【００２３】そして、励振力推定演算部ｃは、第１の演
算装置１５にて計算されたインパルス応答関数と振動応
答計測部ｂで計測した加速度応答の計測データとを第２
の演算装置１７に入力し、周波数領域においての励振力
推定計算を行なう。Then, the excitation force estimation calculation unit c outputs the impulse response function calculated by the first calculation device 15 and the measurement data of the acceleration response measured by the vibration response measurement unit b to the second calculation unit.
To the arithmetic unit 17 to perform excitation force estimation calculation in the frequency domain.
【００２４】上記第２の演算装置１７の演算動作は、次
のようにして行なわれる。第１の演算装置１５にて計算
されたインパルス応答関数と振動応答計測部ｂで計測し
た加速度応答の計測データは、第２の演算装置１７の演
算器２１に入力されて処理され、続いて、複素対数変換
器２２、離散フーリエ逆変換器２３、短ケフレンシ域抽
出器２４、離散フーリエ変換器２５、複素指数変換器２
６、離散フーリエ逆変換器２７で順次処理され、この離
散フーリエ逆変換器２７から励振力推定値が出力され
る。この場合、振動応答及びインパルス応答関数を複素
ケプストラム＾ｘ（τ）に変換して励振力の推定を行な
うが、以下にその詳細について説明する。上記複素ケプ
ストラム＾ｘ（τ）は、時系列ｘ（ｔ）のフーリエ変換
の複素対数の逆フーリエ変換で与えられる。定義式は、
次に示すようにThe arithmetic operation of the second arithmetic unit 17 is performed as follows. The impulse response function calculated by the first arithmetic unit 15 and the measurement data of the acceleration response measured by the vibration response measuring unit b are input to the arithmetic unit 21 of the second arithmetic unit 17 and processed, and subsequently, Complex logarithmic transformer 22, discrete Fourier inverse transformer 23, short kefrenshi region extractor 24, discrete Fourier transformer 25, complex exponential transformer 2
6. The discrete Fourier inverse transformer 27 sequentially processes, and the discrete Fourier inverse transformer 27 outputs the excitation force estimation value. In this case, the excitation force is estimated by converting the vibration response and the impulse response function into a complex cepstrum ＾ x (τ), which will be described in detail below. The complex cepstrum ＾ x (τ) is given by the inverse Fourier transform of the complex logarithm of the Fourier transform of the time series x (t). The definition formula is
As shown below
【００２５】[0025]
【数１】 Ｆ［…］：［…］のフーリエ変換で示される。[Equation 1] F [...]: Indicated by Fourier transform of [...].
【００２６】複素ケプストラム（cepstrum）の名称は、
スペクトラム（spectrum）に逆変換を施したと言う観点
から付けられたものである。また、複素ケプストラム
は、時間と同じ次元の領域の関数であるが、特に周波数
（frequency ）領域の関数に逆フーリエ変換を施したも
のという観点から、ケフレンシ（quefrency ）領域の関
数として定義される。ケフレンシが“０”に近い領域は
時間と対応付けて短ケフレンシ領域、その逆の領域は長
ケフレンシ領域と称する。The name of complex cepstrum is
It was given from the viewpoint that the spectrum was inversely transformed. The complex cepstrum is a function in a domain having the same dimension as time, but is defined as a function in a quefrency domain from the viewpoint of performing an inverse Fourier transform on a function in a frequency domain. An area where the quefrency is close to “0” is called a short quefrency area in association with time, and an area opposite thereto is called a long quefrency area.
【００２７】そして、振動応答及びインパルス応答関数
の複素ケプストラム＾ｘ（τ）を計算し、短ケフレンシ
領域の成分だけを抽出する窓関数処理を施す。周波数ス
ペクトルの共振／***振の影響は長ケフレンシ領域に現
れるため、この窓関数処理（ケフレンシ領域における窓
関数をケフレンシウィンドウ、短ケフレンシ領域の成分
だけを抽出するケフレンシウィンドウをショートパスケ
フレンシウィンドウと称する）により、振動応答／イン
パルス応答関数双方のスペクトルへの共振／***振の影
響を低減することができる。Then, the complex cepstrum ^ x (τ) of the vibration response and the impulse response function is calculated, and the window function process for extracting only the component of the short kefrenshi region is performed. Since the effect of the resonance / anti-resonance of the frequency spectrum appears in the long quefrency region, this window function processing (the window function in the quefrency region is a quefrency window, and the quefrency window for extracting only the components in the short quefrency region is a short path quefrency window) ) Can reduce the effect of resonance / anti-resonance on the spectrum of both the vibration response / impulse response function.
【００２８】構造系の共振／***振は、構造中を伝搬す
る振動の反射に起因するものであるから、この影響を低
減させることは励振力に対する直接応答のみを検出する
ことを意味し、従って、衝撃的励振力の推定に対して
は、精度の向上が期待できる。Resonance / anti-resonance of the structural system is due to the reflection of vibrations propagating in the structure, so reducing this effect means detecting only the direct response to the excitation force, and thus For the estimation of the impulsive excitation force, improvement in accuracy can be expected.
【００２９】インパルス応答関数の複素ケプストラムを
計算する際、周波数応答関数の***振点近傍ではノイズ
の影響が大きく位相値が不定となるため、複素ケプスト
ラム計算値にこれに起因する誤差が含まれる恐れがあ
る。この現象を回避するためインパルス応答関数は、最
小位相条件を満足すると仮定し、周波数応答関数の位相
は振幅値から定める。When the complex cepstrum of the impulse response function is calculated, noise is large in the vicinity of the anti-resonance point of the frequency response function and the phase value becomes indefinite, so the complex cepstrum calculation value may include an error due to this. There is. In order to avoid this phenomenon, it is assumed that the impulse response function satisfies the minimum phase condition, and the phase of the frequency response function is determined from the amplitude value.
【００３０】また、最小位相条件を満たす周波数応答関
数の位相値は、逆ヒルベルト変換で与えられるため、ヒ
ルベルト変換器を用いて最小位相複素ケプストラムを計
算する。Since the phase value of the frequency response function satisfying the minimum phase condition is given by the inverse Hilbert transform, the minimum phase complex cepstrum is calculated using the Hilbert transformer.
【００３１】上記振動応答の複素ケプストラムは、入力
の複素ケプストラムとインパルス応答関数の複素ケプス
トラムとの和で与えられるので、ケフレンシウィンドウ
処理を施した振動応答の複素ケプストラムとの差を取る
ことにより、励振力波形推定値の複素ケプストラムを得
ることができる。そして、これを時系列に変換して励振
力波形推定値を得る。Since the complex cepstrum of the vibration response is given by the sum of the complex cepstrum of the input and the complex cepstrum of the impulse response function, by taking the difference from the complex cepstrum of the vibration response subjected to the Kerenshi window, A complex cepstrum of the excitation force waveform estimation value can be obtained. Then, this is converted into a time series to obtain an excitation force waveform estimated value.
【００３２】次に上記の演算を行なう各演算器の処理機
能について説明する。演算器２１は、離散フーリエ変換
器２１ａ及び離散ヒルベルト逆変換器２１ｂからなり、
まず、離散フーリエ変換器２１ａにより機器稼働時の振
動応答及び予めインパルス応答関数計測部ａにて計測し
た振動応答測定点Ｂと励振力着力点Ａとの間のインパル
ス応答関数ｈ′（ｔ）に離散フーリエ変換を施して周波
数領域のデータに変換する。応答は、時間領域では励振
力と系のインパルス応答の畳み込みで与えられるが（i.
e. ｘ（ｔ）＝ｆ（ｔ）＊ｈ（ｔ））、周波数領域に変
換することにより、励振力スペクトルと周波数応答関数
の積で与えられるようになる（i.e. Ｘ（ω）＝Ｆ
（ω）×Ｈ（ω））。その後、離散ヒルベルト逆変換器
２１ｂで周波数応答関数の振幅値に逆ヒルベルト変換を
施して最小位相条件を満す位相値を計算する。これによ
り位相が不定になる周波数領域が存在することに起因す
る誤差の影響を低減する。図４及び図５は、前記図１３
及び図１４に示す構造系の従来の周波数応答関数に最小
位相条件を投入して計算した周波数応答関数の例であ
り、図４は振幅（加速度／力）を、図５は位相（ｒａ
ｄ）を表している。Next, the processing function of each arithmetic unit for performing the above-mentioned arithmetic will be described. The calculator 21 includes a discrete Fourier transformer 21a and a discrete Hilbert inverse transformer 21b,
First, the discrete Fourier transformer 21a determines the vibration response during device operation and the impulse response function h ′ (t) between the vibration response measurement point B and the excitation force applying point A measured in advance by the impulse response function measuring unit a. Discrete Fourier transform is applied to transform into frequency domain data. The response is given by the convolution of the excitation force and the impulse response of the system in the time domain (i.
e. x (t) = f (t) * h (t)), by transforming into the frequency domain, it can be given by the product of the excitation force spectrum and the frequency response function (ie X (ω) = F
(Ω) × H (ω)). Then, the discrete Hilbert inverse converter 21b performs an inverse Hilbert transform on the amplitude value of the frequency response function to calculate a phase value satisfying the minimum phase condition. This reduces the influence of an error caused by the existence of a frequency region where the phase is indefinite. 4 and 5 are similar to FIG.
FIG. 4 is an example of a frequency response function calculated by applying the minimum phase condition to the conventional frequency response function of the structural system shown in FIG. 14, FIG. 4 shows amplitude (acceleration / force), and FIG.
d) is shown.
【００３３】複素対数変換器２２は、応答スペクトルＸ
（ω）と、周波数応答関数スペクトルＨ′（ω）の複素
対数をとる。応答スペクトルの複素対数「＾Ｘ（ω）＝
logＸ（ω）＝log ｜Ｘ（ω）｜＋ｊφ」は、励振力ス
ペクトルの複素対数と周波数応答関数の複素対数の和と
なる（i.e. ＾Ｘ（ω）＝＾Ｆ（ω）×＾Ｈ（ω））。The complex logarithmic converter 22 has a response spectrum X.
(Ω) and the complex logarithm of the frequency response function spectrum H ′ (ω). The complex logarithm of the response spectrum "＾ X (ω) =
log X (ω) = log | X (ω) | + jφ ”is the sum of the complex logarithm of the excitation force spectrum and the complex logarithm of the frequency response function (ie ^ X (ω) = ^ F (ω) × ^ H ( ω)).
【００３４】離散フーリエ逆変換器２３は、応答の対数
スペクトル＾Ｘ（ω）と、対数周波数応答関数＾Ｈ′
（ω）に離散フーリエ逆変換を施し、ケフレンシ領域の
データ（複素ケプストラム）に変換する。図６は、この
構造系のインパルス応答関数の複素ケプストラムの例を
示したものである。構造系の共振の影響は、長ケフレン
シ領域に現れる。The inverse discrete Fourier transformer 23 has a logarithmic spectrum ^ X (ω) of the response and a logarithmic frequency response function ^ H '.
An inverse discrete Fourier transform is applied to (ω) to convert it into data (complex cepstrum) in the kefrenc region. FIG. 6 shows an example of the complex cepstrum of the impulse response function of this structural system. The effect of the resonance of the structural system appears in the long-frequency region.
【００３５】短ケフレンシ域抽出器２４は、複素ケプス
トラムに短いケフレンシのデータだけ抽出する窓関数処
理を施す。窓関数の幅は、対象とする機器により変化さ
せる必要があるため、外部から入力可能とする。図７
は、この窓関数処理、つまり、ケフレンシウィンドウ処
理を施した複素ケプストラムの例を示したもので、図６
の短ケフレンシ領域のデータのみを抽出したものであ
る。The short kefrenshi area extractor 24 performs a window function process for extracting only the short kefrenshi data on the complex cepstrum. Since the width of the window function needs to be changed depending on the target device, it can be input from the outside. Figure 7
6 shows an example of the complex cepstrum that has been subjected to this window function processing, that is, the keflencity window processing.
Only the data of the short quefrency area is extracted.
【００３６】離散フーリエ変換器２５は、窓関数処理を
施した応答とインパルス応答関数それぞれの複素ケプス
トラムの演算により、励振力推定値の複素ケプストラム
を求めた後、これにフーリエ変換を施し、周波数領域に
変換する。図８及び図９は、ケフレンシウィンドウ処理
を施した周波数応答関数の例、すなわち、図７の複素ケ
プストラムを周波数領域に変換したものであり、図８は
振幅、図９は位相を表している。The discrete Fourier transformer 25 obtains the complex cepstrum of the excitation force estimation value by calculating the complex cepstrum of the response subjected to the window function processing and the impulse response function, and then performs the Fourier transform on the complex cepstrum, thereby performing the Fourier transform on the frequency domain. Convert to. 8 and 9 show an example of a frequency response function that has been subjected to the kefrenshi window process, that is, the complex cepstrum of FIG. 7 is transformed into the frequency domain, and FIG. 8 shows the amplitude and FIG. 9 shows the phase. .
【００３７】複素指数変換器２６は、励振力推定値スペ
クトルの複素対数を真数に変換する。離散フーリエ逆変
換器２７は、励振力推定値スペクトルに離散フーリエ逆
変を施すことにより、励振力推定値を時系列として求め
る。The complex exponential converter 26 converts the complex logarithm of the excitation force estimation value spectrum into an antilogarithm. The discrete Fourier inverse transformer 27 obtains the excitation force estimated value as a time series by applying the discrete Fourier inverse transformation to the excitation force estimated value spectrum.
【００３８】上記のように第２の演算装置１７では、振
動応答及びインパルス応答関数を複素ケプストラムに変
換し、ケフレンシ領域で励振力の推定を行なう。図１０
は、破線で示す実際の励振力波形と図８、図９に示した
周波数応答関数をもって推定した実線で示す励振力波形
とを比較した図である。この図から明らかなように、本
発明によれば残留振動波形のない良好な推定結果を得る
ことができる。As described above, in the second arithmetic unit 17, the vibration response and the impulse response function are converted into the complex cepstrum, and the excitation force is estimated in the kefrenc region. FIG.
FIG. 10 is a diagram comparing an actual excitation force waveform shown by a broken line and an excitation force waveform shown by a solid line estimated by the frequency response function shown in FIGS. 8 and 9. As is clear from this figure, according to the present invention, it is possible to obtain a good estimation result without a residual vibration waveform.
【００３９】[0039]
【発明の効果】以上詳記したように本発明によれば、ノ
イズレベルあるいは計測機器のダイナミックレンジの制
限により正確に測定できない場合においても、共振／反
共振の影響をショートパスケフレンシウィンドウ処理に
より除去することにより、ノイズに対する安定性が強
く、振幅、加振力持続時間ともに妥当な推定結果を得る
ことができる。従って、本発明による励振力推定装置
は、従来装置に比較して優れた機能を有し、特に衝撃的
加振力波形の同定に有効である。As described above in detail, according to the present invention, even if the noise level or the dynamic range of the measuring instrument cannot be accurately measured, the influence of resonance / anti-resonance can be reduced by the short path Kefrency window processing. By removing it, the stability against noise is strong, and it is possible to obtain reasonable estimation results for both amplitude and excitation force duration. Therefore, the excitation force estimating device according to the present invention has excellent functions as compared with the conventional device, and is particularly effective for identifying a shocking excitation force waveform.
【図１】本発明の一実施形態に係る励振力推定装置の構
成を示すブロック図。FIG. 1 is a block diagram showing a configuration of an excitation force estimation device according to an embodiment of the present invention.
【図２】同実施形態における第２の演算装置の詳細を示
す構成図。FIG. 2 is a configuration diagram showing details of a second arithmetic unit in the embodiment.
【図３】同実施形態における第２の演算装置内の演算器
２１の詳細な構成を示すブロック図。FIG. 3 is a block diagram showing a detailed configuration of a computing unit 21 in the second computing device according to the same embodiment.
【図４】最小位相条件を導入した構造系の周波数応答関
数の振幅を示す図。FIG. 4 is a diagram showing the amplitude of a frequency response function of a structural system in which the minimum phase condition is introduced.
【図５】最小位相条件を導入した構造系の周波数応答関
数の位相を示す図。FIG. 5 is a diagram showing a phase of a frequency response function of a structural system in which a minimum phase condition is introduced.
【図６】構造系のインパルス応答関数の複素ケプストラ
ムの例を示す図。FIG. 6 is a diagram showing an example of a complex cepstrum of an impulse response function of a structural system.
【図７】ケフレンシウィンドウ処理を施した複素ケプス
トラムの例を示す図。FIG. 7 is a diagram showing an example of a complex cepstrum that has been subjected to Kefrency window processing.
【図８】ケフレンシウィンドウ処理を施した周波数応答
関数の振幅を示す図。FIG. 8 is a diagram showing the amplitude of a frequency response function that has been subjected to a Kefrency window process.
【図９】ケフレンシウィンドウ処理を施した周波数応答
関数の位相を示す図。FIG. 9 is a diagram showing a phase of a frequency response function that has been subjected to a Kefrency window process.
【図１０】本発明の手法によって求めた励振力波形の例
（ピストンスラップ力）を示す図。FIG. 10 is a diagram showing an example of an excitation force waveform (piston slap force) obtained by the method of the present invention.
【図１１】従来の励振力推定装置の構成を示すブロック
図。FIG. 11 is a block diagram showing a configuration of a conventional excitation force estimation device.
【図１２】従来の励振力推定装置の第２の演算装置の構
成を示すブロック図。FIG. 12 is a block diagram showing the configuration of a second arithmetic unit of a conventional excitation force estimation apparatus.
【図１３】最小位相条件を導入した構造系の周波数応答
関数の振幅を示す図。FIG. 13 is a diagram showing the amplitude of the frequency response function of the structural system in which the minimum phase condition is introduced.
【図１４】最小位相条件を導入した構造系の周波数応答
関数の位相を示す図。FIG. 14 is a diagram showing a phase of a frequency response function of a structural system in which a minimum phase condition is introduced.
【図１５】従来の手法によって求めた励振力波形の例
（ピストンスラップ力）を示す図。FIG. 15 is a diagram showing an example of an excitation force waveform (piston slap force) obtained by a conventional method.
１１ 被測定機器 １２ インパルスハンマ １３ 加速度検出器 １４ 第１のメモリ装置 １５ 第１の演算装置 １６ 第２のメモリ装置 １７ 第２の演算装置 ２１ 演算器 ２１ａ 離散フーリエ変換器 ２１ｂ 離散ヒルベルト逆変換器 ２２ 複素対数変換器 ２３ 離散フーリエ逆変換器 ２４ 短ケフレンシ域抽出器 ２５ 離散フーリエ変換器 ２６ 複素指数変換器 ２７ 離散フーリエ逆変換器 11 device under test 12 impulse hammer 13 acceleration detector 14 first memory device 15 first arithmetic device 16 second memory device 17 second arithmetic device 21 arithmetic device 21a discrete Fourier transformer 21b discrete Hilbert inverse transformer 22 Complex logarithmic converter 23 Discrete Fourier inverse transformer 24 Short Kefrenshi region extractor 25 Discrete Fourier transformer 26 Complex exponential transformer 27 Discrete Fourier inverse transformer
Claims (1)
との間のインパルス応答関数を用いて構造系に負荷され
る励振力を推定する励振力推定装置において、 上記構造系の振動応答測定点の振動加速度を検出する加
速度検出器と、 この加速度検出器により検出された加速度応答及び加振
試験時に上記構造系に加えられる励振力信号を記憶する
第１の記憶手段と、 この第１の記憶手段に記憶された加振試験時の励振力及
び加速度応答に基づいて上記構造系の振動応答測定点と
励振力着力点との間のインパルス応答関数を算出する第
１の演算手段と、 この第１の演算手段により計算されたインパルス応答関
数と上記加速度検出器により検出される機器稼働時の加
速度応答を記憶する第２の記憶手段と、 この第２の記憶手段に記憶されたインパルス応答関数及
び機器稼働時の加速度応答に基づいて構造系に負荷され
る励振力推定値を計算する第２の演算手段とを具備し、 上記第２の演算手段は、第２の記憶手段に記憶されたイ
ンパルス応答関数及び機器稼働時の加速度応答を周波数
領域のデータに変換する離散フーリエ変換器及び周波数
応答関数の振幅値に逆ヒルベルト変換を施して最小位相
条件を満す位相値を計算する離散ヒルベルト逆変換器か
らなる演算器と、上記周波数応答関数と応答スペクトル
との複素対数をとる複素対数変換器と、応答の対数スペ
クトルと対数周波数応答関数に離散フーリエ逆変換を施
し、複素ケプストラムに変換する離散フーリエ逆変換器
と、上記複素ケプストラムに窓関数処理を施して短いケ
フレンシのデータだけを抽出する短ケフレンシ域抽出器
と、上記窓関数処理を施した応答とインパルス応答関数
それぞれの複素ケプストラムの演算により、励振力推定
値の複素ケプストラムを求めた後、フーリエ変換により
周波数領域に変換する離散フーリエ変換器と、励振力ス
ペクトルの複素対数を真数に変換する複素指数変換器
と、上記真数に変換した励振力推定値スペクトルに離散
フーリエ逆変換を施して励振力推定値を時系列として求
める離散フーリエ逆変換器とからなることを特徴とする
励振力推定装置。1. An excitation force estimation device for estimating an excitation force applied to a structural system using an impulse response function between a vibration response measurement point of the structural system and an excitation force applying point, wherein the vibration response of the structural system is An acceleration detector for detecting the vibration acceleration of the measurement point; a first storage means for storing the acceleration response detected by the acceleration detector and the exciting force signal applied to the structural system during the vibration test; First calculating means for calculating an impulse response function between the vibration response measurement point of the structural system and the excitation force applying point based on the excitation force and the acceleration response during the vibration test stored in the storage means of Second storage means for storing the impulse response function calculated by the first calculation means and the acceleration response during device operation detected by the acceleration detector, and the impulse storage function stored in the second storage means. A second calculation means for calculating an estimated value of the excitation force applied to the structural system based on the response function and the acceleration response during operation of the device, wherein the second calculation means is stored in the second storage means. Discrete Fourier transformer that transforms the impulse response function and acceleration response during equipment operation into data in the frequency domain and the discrete Fourier transformer that calculates the phase value that satisfies the minimum phase condition by applying the inverse Hilbert transform to the amplitude value of the frequency response function An operation unit consisting of a Hilbert inverse transformer, a complex logarithmic transformer that takes the complex logarithm of the frequency response function and the response spectrum, and a discrete Fourier inverse transform on the logarithmic spectrum of the response and the logarithmic frequency response function, and then converted to a complex cepstrum. A discrete Fourier inverse transformer, and a short kefrenshi region extractor for subjecting the complex cepstrum to window function processing to extract only short kefrenshi data, After calculating the complex cepstrum of the excitation force estimation value by calculating the complex cepstrum of the response and impulse response function for which the window function processing has been performed, the discrete Fourier transformer that transforms into the frequency domain by Fourier transform, and the excitation force spectrum It consists of a complex exponential converter that converts the complex logarithm to an antilogarithm, and a discrete Fourier inverse transformer that calculates the excitation force estimate as a time series by applying the inverse discrete Fourier transform to the excitation force estimate spectrum converted to the above-mentioned antilogarithm. An excitation force estimation device characterized by the above.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5188396A JPH09243480A (en) | 1996-03-08 | 1996-03-08 | Apparatus for estimating excitation force |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5188396A JPH09243480A (en) | 1996-03-08 | 1996-03-08 | Apparatus for estimating excitation force |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09243480A true JPH09243480A (en) | 1997-09-19 |
Family
ID=12899289
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5188396A Withdrawn JPH09243480A (en) | 1996-03-08 | 1996-03-08 | Apparatus for estimating excitation force |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH09243480A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113033894A (en) * | 2021-03-24 | 2021-06-25 | 南方电网数字电网研究院有限公司 | Daily electricity consumption prediction method and device, computer equipment and storage medium |
-
1996
- 1996-03-08 JP JP5188396A patent/JPH09243480A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113033894A (en) * | 2021-03-24 | 2021-06-25 | 南方电网数字电网研究院有限公司 | Daily electricity consumption prediction method and device, computer equipment and storage medium |
| CN113033894B (en) * | 2021-03-24 | 2023-05-02 | 南方电网数字电网研究院有限公司 | Daily electricity quantity prediction method, device, computer equipment and storage medium |
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