JPH0236910B2 - - Google Patents
Info
- Publication number
- JPH0236910B2 JPH0236910B2 JP60192024A JP19202485A JPH0236910B2 JP H0236910 B2 JPH0236910 B2 JP H0236910B2 JP 60192024 A JP60192024 A JP 60192024A JP 19202485 A JP19202485 A JP 19202485A JP H0236910 B2 JPH0236910 B2 JP H0236910B2
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- waveform
- value
- vibration waveform
- input vibration
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 238000005070 sampling Methods 0.000 claims description 11
- 238000001514 detection method Methods 0.000 claims description 9
- 238000000034 method Methods 0.000 description 8
- 230000001133 acceleration Effects 0.000 description 6
- 238000004364 calculation method Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000009499 grossing Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 206010037844 rash Diseases 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000010183 spectrum analysis Methods 0.000 description 1
- 230000001131 transforming effect Effects 0.000 description 1
Landscapes
- Measuring Frequencies, Analyzing Spectra (AREA)
- Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
- Geophysics And Detection Of Objects (AREA)
Description
【発明の詳細な説明】
（産業上の利用分野）
この発明は振動波形の卓越周波数を連続的に算
出する装置に関する。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an apparatus for continuously calculating the dominant frequency of a vibration waveform.
（従来の技術）
文献名
溝上ほか、1980，1980年伊豆半島東方沖の群発
地震のリアルタイム検測、地震研究所イ報、
vol.55，pp949−1015
今井ほか、1979，1973年浅間火山噴火に伴う群
発地震について（第１報）スペクトル解析、地震
研究所イ報、vol.54，pp161−186
従来このような分野では振動がゼロ線と交差す
る時間間隔により推定するゼロクロス法、一定期
間内の波形データをフーリエ変換してスペクトル
を計算するFFT法などの方法で振動波形の周波
数を算出していた。(Prior art) Title of document: Mizokami et al., 1980, Real-time measurement of earthquake swarms off the eastern coast of the Izu Peninsula, Earthquake Research Institute Newsletter,
vol.55, pp949-1015 Imai et al., Spectral analysis of earthquake swarms associated with the 1979 and 1973 Asama eruptions (first report), Earthquake Research Institute newsletter, vol.54, pp161-186 Conventionally, in this field, vibration The frequency of vibration waveforms has been calculated using methods such as the zero-cross method, which estimates based on the time interval at which the waveform crosses the zero line, and the FFT method, which calculates the spectrum by Fourier transforming waveform data within a certain period of time.
（発明が解決しようとする問題点）
ゼロクロス法ではゼロクロスする間の平均的な
周波数しか算出できない。FFTでは計算時間が
かかり卓越周期をさらに別の方法で算出しなけれ
ばならないという欠点があり、連続的に振動波形
の周波数を得ることは困難であつた。(Problems to be Solved by the Invention) The zero-crossing method can only calculate the average frequency during zero-crossing. FFT has the disadvantage that calculation time is required and the dominant period must be calculated using another method, making it difficult to continuously obtain the frequency of the vibration waveform.
この発明は以上の欠点を解決するために漸化式
により短時間に連続的に卓越周波数を算出するこ
とを目的としている。 In order to solve the above-mentioned drawbacks, the present invention aims to calculate dominant frequencies continuously in a short period of time using a recurrence formula.
（問題点を解決するための手段）
この発明は、入力振動波形をサンプリングして
オフセツトレベルを除去した値と、前記オフセツ
トレベルを除去した値より入力振動波形の指数平
滑値とを得る第１の手段と、
前記オフセツトレベルを除去した値の微分又は
積分波形の指数平滑値を得る第２の手段と、
前記第１の手段からの入力振動波形の指数平滑
値と前記第２の手段からの微分又は積分波形の指
数平均値との比より入力振動波形の卓越周波数を
得る第３の手段と
を有することを特徴とした卓越周波数検出装置で
あり、さらには前記第３の手段からの周波数出力
を検知する第４の手段を有する。(Means for Solving the Problems) The present invention provides a method for obtaining an exponentially smoothed value of an input vibration waveform from a value obtained by sampling an input vibration waveform and removing an offset level, and a value obtained by removing the offset level. a second means for obtaining an exponentially smoothed value of the differential or integral waveform of the value from which the offset level has been removed; and an exponentially smoothed value of the input vibration waveform from the first means and the second means. A dominant frequency detection device characterized by having a third means for obtaining a dominant frequency of an input vibration waveform from a ratio with an exponential average value of a differential or integral waveform from the third means. It has fourth means for detecting the frequency output.
（作用及び実施例）
第１図はこの発明の実施例を示すブロツク図で
ある。第１図は地震波形の卓越周期検出について
例示する。１は地動（速度成分）を検出するセン
サで上下方向、東西方向、南北方向の３成分の地
動を検出する形式のものである。２はセンサ１よ
りの波形信号を増幅するアンプ、３はバツフアア
ンプ、４は３成分の地動を処理する制御処理装置
である。制御処理装置４は標本化部１１、加速度
変換部１２、周波数算出部１３、地震波検出部１
４より構成される。(Operation and Examples) FIG. 1 is a block diagram showing an example of the present invention. FIG. 1 illustrates the detection of a dominant period of an earthquake waveform. 1 is a sensor that detects ground motion (velocity component), and is of a type that detects three components of ground motion: vertical, east-west, and north-south directions. 2 is an amplifier that amplifies the waveform signal from the sensor 1, 3 is a buffer amplifier, and 4 is a control processing device that processes three components of ground motion. The control processing device 4 includes a sampling section 11, an acceleration conversion section 12, a frequency calculation section 13, and a seismic wave detection section 1.
Consists of 4.
以下第１図のブロツク図に示される実施例の動
作について、第２図のフローチヤートとともに説
明する。センサ１は常時設置されている地点の地
動（速度成分）を検出しこれを電気信号に変換し
て制御処理装置４に送出している。制御処理装置
４はセンサ１で検出されて絶えず送られてくる地
動の各成分の情報を入力する。標本化部１１は所
定の時間間隔（例えば1/50〜1/150秒）で取込み、
その過去何回分かのサンプリング情報の平均値よ
り入力データの直流分であるオフセツトレベルの
算出を行う。このオフセツトレベルは時々刻刻得
られるサンプリング情報によつて絶えず更新され
ている。ついでセンサ１よつて検出されて時々
刻々送られてくる上下方向・東西方向・南北方向
の３成分の地動情報のサンプリング値からオフセ
ツトレベルを除去した値x1（ｔ），x2（ｔ），x3（ｔ）
に基づいて指数平滑値ax1（ｔ），ax2（ｔ），ax3
（ｔ）を算出する。指数平滑値axi（ｔ）（ただしｉ
＝１，２，３）の計算手法の一例を次式に示す。 The operation of the embodiment shown in the block diagram of FIG. 1 will be described below with reference to the flowchart of FIG. 2. The sensor 1 detects ground motion (velocity component) at a point where it is constantly installed, converts it into an electrical signal, and sends it to the control processing device 4. The control processing device 4 inputs information on each component of ground motion detected by the sensor 1 and constantly sent. The sampling unit 11 captures images at predetermined time intervals (for example, 1/50 to 1/150 seconds),
The offset level, which is the direct current component of the input data, is calculated from the average value of the past sampling information. This offset level is constantly updated based on sampling information obtained from time to time. Next, the values x 1 (t), x 2 (t) are obtained by removing the offset level from the sampling values of the three-component ground motion information in the vertical direction, east-west direction, and north-south direction that is detected by sensor 1 and sent from time to time. ,x 3 (t)
Based on the exponential smoothing values ax 1 (t), ax 2 (t), ax 3
(t) is calculated. Exponentially smoothed value axi(t) (where i
=1, 2, 3) is shown in the following equation.
axi（ｔ）＝axi（ｔ−１）×ａ＋xi2（ｔ） (1)
または、
axi（ｔ）＝axi（ｔ−１）×ａ＋｜xi（ｔ）｜(2
)
ａは0.9程度の定数である。標本化部１１はxi
（ｔ）を加速度変換部１２に、axi（ｔ）を周波数
算出部１３に、さらにxi（ｔ），axi（ｔ）を地震波
検出部１４に送出する。周波数算出部１２ではxi
（ｔ）よりその微分波形信号ai（ｔ）と微分波形信
号の指数平滑値aai（ｔ）を算出し周波数算出部１
３に送出する。xi（ｔ）よりai（ｔ）を算出する方
法については特許番号第1224924号地震計システ
ム（特願昭54−122559，出願公告昭59−2357）に
明らかにされている。 axi(t)=axi(t-1)×a+xi 2 (t) (1) or axi(t)=axi(t-1)×a+|xi(t)|(2
) a is a constant of about 0.9. The sampling unit 11
(t) is sent to the acceleration converter 12, axi(t) is sent to the frequency calculator 13, and xi(t) and axi(t) are sent to the seismic wave detector 14. In the frequency calculation section 12, xi
(t), the differential waveform signal ai(t) and the exponential smoothing value aai(t) of the differential waveform signal are calculated, and the frequency calculation unit 1
Send to 3. The method of calculating ai(t) from xi(t) is disclosed in Patent No. 1224924 Seismograph System (Japanese Patent Application No. 122559/1982, Publication of Application 1982/2357).
速度の正弦波とその微分波形である加速度の間
には次の関係がある。ここで、速度Ｖ、加速度
Ａ、周波数Ｆである。一般にＶ＝bsinωtとする
と、Ａ＝bωcosωtである。Ｖの振幅はｂであり、
Ａの振幅はbωであるから、Ａの振幅をＶの振幅
で除すと、（Ａの振幅）／（Ｖの振幅）＝bω／ｂ
＝ω＝2πFとなり、振動数Ｆの2π倍が得られる。 The following relationship exists between the velocity sine wave and its differential waveform, acceleration. Here, they are velocity V, acceleration A, and frequency F. Generally, if V=bsinωt, then A=bωcosωt. The amplitude of V is b,
Since the amplitude of A is bω, dividing the amplitude of A by the amplitude of V gives (amplitude of A)/(amplitude of V) = bω/b
= ω = 2πF, and the frequency F times 2π is obtained.
2πF＝（Ａの振幅）／（Ｖの振幅） (3)
振動波形は正弦波ではないが、正弦波の集まり
であり、振動波形とその微分または積分波形の振
幅比からその振動の卓越周波数を推定できる。こ
こで取り扱う振幅値は瞬間瞬間の振幅ではなく、
振動波形の包絡線としての振幅値である。そこで
信号以外のノイズ（ばらつきや揺らぎ等）の影響
を除去する意味も含めて、それぞれの波形の包絡
線形状（いわゆる振動の変動）を連続的に把握す
るための指数平滑値を利用することとする。 2πF = (amplitude of A) / (amplitude of V) (3) The vibration waveform is not a sine wave, but is a collection of sine waves, and the dominant frequency of the vibration can be determined from the amplitude ratio of the vibration waveform and its differential or integral waveform. It can be estimated. The amplitude value handled here is not the instantaneous amplitude, but
This is the amplitude value as the envelope of the vibration waveform. Therefore, it is important to use exponential smoothing values to continuously understand the envelope shape of each waveform (so-called vibration fluctuation), including the purpose of removing the effects of noise other than signals (variations, fluctuations, etc.). do.
周波数検出部１３では標本化部１１より送られ
てきたaxi（ｔ）と加速度変換部１２より送られて
きたaai（ｔ）より次式で周波数ｆ（ｔ）を算出し
地震波検出部１４と制御処理装置４の外部に送出
する。 The frequency detection section 13 calculates the frequency f(t) using the following formula from the axi(t) sent from the sampling section 11 and the aai(t) sent from the acceleration conversion section 12, and controls the frequency f(t) with the seismic wave detection section 14. It is sent to the outside of the processing device 4.
ｆ（ｔ）＝aai（ｔ）／（2π・axi（ｔ）） (4)
第３図は周波数と振幅の異なる正弦波を実施例
に入力してその卓越周波数を計算させた例であ
る。振幅の大きさに惑わされずに正弦波の周波数
の変動とともに計算された卓越周波数も正しく変
化していることがわかる。第４図は実際の地震波
を処理した結果である。地震波の到来とともに周
波数が変動していることがわかる。このため、周
波数の変動を検出することにより地震波の到来を
検出できることがわかる。 f(t)=aai(t)/(2π·axi(t)) (4) FIG. 3 is an example in which sine waves with different frequencies and amplitudes are input to the embodiment and its dominant frequency is calculated. It can be seen that the calculated dominant frequency changes correctly as the frequency of the sine wave changes without being confused by the magnitude of the amplitude. Figure 4 shows the results of processing actual seismic waves. It can be seen that the frequency changes with the arrival of seismic waves. Therefore, it can be seen that the arrival of seismic waves can be detected by detecting frequency fluctuations.
周波数の変化より地震波の到来を検出するため
に、周波数の平均値｜ｆ（ｔ）｜とそのばらつき
（分散σf（ｔ））を計算する。周波数ｆ（ｔ）がトリ
ガレベルを連続してｎサンプル越えたならば地震
波の到来とみなす。ｎは３〜10程度の定数であ
る。トリガレベルは以下の式で算出する。 In order to detect the arrival of seismic waves from changes in frequency, the average value |f(t)| of the frequency and its dispersion (variance σf(t)) are calculated. If the frequency f(t) exceeds the trigger level for n samples consecutively, it is assumed that a seismic wave has arrived. n is a constant of about 3 to 10. The trigger level is calculated using the following formula.
トリガレベル＝｜ｆ（ｔ）｜±ａ×σf（ｔ） ここでａは２〜３程度の定数である。 Trigger level = |f(t)|±a×σf(t) Here, a is a constant of about 2 to 3.
到来した波形が人工ノイズか自然地震かどうか
の判断は、地震とみなしたときより例えば１秒間
の周波数の最低値が例えば５Hzより低い周波数か
どうかによつて行う。例えば、５Hzより低いとき
には自然地震とみなし、５Hzより高いときには人
工ノイズとみなす。 A determination as to whether the arriving waveform is artificial noise or a natural earthquake is made based on whether the lowest frequency per second is, for example, 5 Hz lower than when it is considered to be an earthquake. For example, if it is lower than 5Hz, it is considered a natural earthquake, and if it is higher than 5Hz, it is considered to be artificial noise.
（発明の効果）
従来、地震波の到来は地震波の振幅の増大での
み自動的に検出をおこなつていた。しかし、人間
は振幅の変化ざけでなく周波数の変化でも地震波
の到来を検出している。機械では、周波数の変化
を自動的に検出する簡略な方法がなかつたため周
波数の変化により地震波の到来を自動的に検出す
ることができなかつた。振幅の変化だけでなく周
波数の変化を同時に検出した地震波の到来を検出
する精度を向上することができる。(Effects of the Invention) Conventionally, the arrival of seismic waves has been automatically detected only when the amplitude of the seismic waves increases. However, humans detect the arrival of seismic waves not only by changes in amplitude but also by changes in frequency. Machines have not been able to automatically detect the arrival of seismic waves based on changes in frequency because there is no simple way to automatically detect changes in frequency. It is possible to improve the accuracy of detecting the arrival of seismic waves by simultaneously detecting not only changes in amplitude but also changes in frequency.
第１図は本発明の一実施例のブロツク図、第２
図は本発明を説明するフロー図、第３図、第４図
は本発明を適用した波形図である。
１……センサ、２……アンプ、３……バツフア
アンプ、４……制御処理装置、１１……標本化
器、１２……加速度変換部、１３……周波数算出
部、１４……地震波検出部。
FIG. 1 is a block diagram of one embodiment of the present invention, and FIG.
The figure is a flow diagram for explaining the present invention, and FIGS. 3 and 4 are waveform diagrams to which the present invention is applied. DESCRIPTION OF SYMBOLS 1... Sensor, 2... Amplifier, 3... Buffer amplifier, 4... Control processing device, 11... Sampling device, 12... Acceleration conversion section, 13... Frequency calculation section, 14... Seismic wave detection section.
Claims (1)
レベルを除去した値と、前記オフセツトレベルを
除去した値より入力振動波形の指数平滑値とを得
る第１の手段と、 前記オフセツトレベルを除去した値の微分又は
積分波形の指数平滑値を得る第２の手段と、 前記第１の手段からの入力振動波形の指数平滑
値と前記第２の手段からの微分又は積分波形の指
数平滑値との比より入力振動波形の卓越周波数を
得る第３の手段と を有することを特徴とした卓越周波数検出装置。 ２ 入力振動波形をサンプリングしてオフセツト
レベルを除去した値と、前記オフセツトレベルを
除去した値より入力振動波形の指数平均値とを得
る第１の手段と、 前記オフセツトレベルを除去した値の微分又は
積分波形の指数平滑値を得る第２の手段と、 前記第１の手段からの入力振動波形の指数平滑
値と前記第２の手段からの微分又は積分波形の指
数平滑値との比より入力振動波形の卓越周波数を
得る第３の手段と 前記第３の手段からの周波数出力を検知する第
４の手段 とを有することを特徴とした卓越周波数検出装
置。 ３ 第４の手段として周波数出力の変化を検知す
ることを特徴とする特許請求の範囲第２項記載の
卓越周波数検出装置。 ４ 第４の手段として周波数出力を所定の周波数
を基準としてその高低を検知することを特徴とし
た特許請求の範囲第２項記載の卓越周波数検出装
置。[Scope of Claims] 1. A first means for obtaining an exponentially smoothed value of the input vibration waveform from a value obtained by sampling the input vibration waveform and removing the offset level, and a value obtained by removing the offset level; a second means for obtaining an exponentially smoothed value of the differential or integral waveform of the value from which the set level has been removed; and an exponentially smoothed value of the input vibration waveform from the first means and the differential or integral waveform from the second means. and third means for obtaining the dominant frequency of the input vibration waveform from a ratio with an exponentially smoothed value. 2. A first means for obtaining a value obtained by sampling an input vibration waveform and removing an offset level, and an exponential average value of the input vibration waveform from the value obtained by removing the offset level, and a value obtained by removing the offset level. a second means for obtaining an exponentially smoothed value of the differential or integral waveform of the input vibration waveform; and a ratio of the exponentially smoothed value of the input vibration waveform from the first means to the exponentially smoothed value of the differential or integral waveform from the second means. A dominant frequency detection device comprising: a third means for obtaining a dominant frequency of an input vibration waveform; and a fourth means for detecting a frequency output from the third means. 3. The dominant frequency detection device according to claim 2, wherein the fourth means detects a change in frequency output. 4. The dominant frequency detection device according to claim 2, wherein the fourth means detects the height of the frequency output with reference to a predetermined frequency.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60192024A JPS6252484A (en) | 1985-09-02 | 1985-09-02 | Apparatus for calculating excellent frequency |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60192024A JPS6252484A (en) | 1985-09-02 | 1985-09-02 | Apparatus for calculating excellent frequency |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6252484A JPS6252484A (en) | 1987-03-07 |
| JPH0236910B2 true JPH0236910B2 (en) | 1990-08-21 |
Family
ID=16284327
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60192024A Granted JPS6252484A (en) | 1985-09-02 | 1985-09-02 | Apparatus for calculating excellent frequency |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6252484A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6902790B2 (en) * | 2018-03-15 | 2021-07-14 | 国立研究開発法人防災科学技術研究所 | Tsunami prediction system |
-
1985
- 1985-09-02 JP JP60192024A patent/JPS6252484A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6252484A (en) | 1987-03-07 |
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