JP2000121402A - Ultrasonic flow velocity meter - Google Patents
Ultrasonic flow velocity meterInfo
- Publication number
- JP2000121402A JP2000121402A JP10289094A JP28909498A JP2000121402A JP 2000121402 A JP2000121402 A JP 2000121402A JP 10289094 A JP10289094 A JP 10289094A JP 28909498 A JP28909498 A JP 28909498A JP 2000121402 A JP2000121402 A JP 2000121402A
- Authority
- JP
- Japan
- Prior art keywords
- ultrasonic
- circuit
- driving
- detection circuit
- output
- 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.)
- Granted
Links
Landscapes
- Measuring Volume Flow (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、気体や液体の超音
波流速計に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas or liquid ultrasonic velocity meter.
【０００２】[0002]
【従来の技術】従来の超音波流速計は、図８に示すよう
なものが一般的であった。この装置は流体の流れる測定
経路１に設置した超音波センサ２と、超音波センサ２を
駆動する駆動回路３と、駆動回路３にスタート信号を出
力する制御部４と、超音波の伝播時間を測定するタイマ
５と、タイマ５から測定データを受け取る演算部６と、
超音波センサ２から送信した超音波を受ける超音波セン
サ７と、超音波センサ７の出力を利得制御回路８の出力
に応じた増幅率で増幅する可変利得アンプ９と、可変利
得アンプ９の出力と基準電圧とを比較し大小関係が反転
したときにタイマ５を停止させるタイミング検知回路１
０と、可変利得アンプ９の出力レベルを検知し利得制御
回路８に出力するレベル検知回路１１とを有していた。2. Description of the Related Art Conventional ultrasonic velocimeters are generally as shown in FIG. The apparatus includes an ultrasonic sensor 2 installed on a measurement path 1 through which a fluid flows, a driving circuit 3 for driving the ultrasonic sensor 2, a control unit 4 for outputting a start signal to the driving circuit 3, and A timer 5 for measuring, an arithmetic unit 6 for receiving measurement data from the timer 5,
An ultrasonic sensor 7 for receiving the ultrasonic wave transmitted from the ultrasonic sensor 2, a variable gain amplifier 9 for amplifying the output of the ultrasonic sensor 7 with an amplification factor according to the output of the gain control circuit 8, and an output of the variable gain amplifier 9 Detection circuit 1 for comparing timer and reference voltage and stopping timer 5 when the magnitude relationship is reversed
0, and a level detection circuit 11 for detecting the output level of the variable gain amplifier 9 and outputting it to the gain control circuit 8.
【０００３】そして、上記超音波流速計は、制御部４か
らスタート信号を受けた駆動回路３が超音波センサ２を
一定時間パルス駆動を行うと同時にタイマ５は制御部４
からの信号によってに時間計測始める。パルス駆動され
た超音波センサ２からは超音波が送信される。超音波セ
ンサ２から送信した超音波は被測定流体中を伝搬し超音
波センサ６で受信される。超音波センサ７の受信出力
は、可変利得アンプ９において制御部４が設定した増幅
率によって増幅される。そして可変利得アンプ９の出力
を受けたタイミング検知回路１０で超音波の受信を判定
しタイマ５を停止させる。そして制御部４ではタイマ５
から得た時間情報ｔから（式１）によって流速を求め
る。[0003] In the above ultrasonic current meter, the driving circuit 3 which receives a start signal from the control unit 4 drives the ultrasonic sensor 2 in a pulsed manner for a predetermined time, and at the same time, the timer 5 controls the control unit 4.
Start time measurement by the signal from. Ultrasonic waves are transmitted from the pulse-driven ultrasonic sensor 2. The ultrasonic wave transmitted from the ultrasonic sensor 2 propagates in the fluid to be measured and is received by the ultrasonic sensor 6. The reception output of the ultrasonic sensor 7 is amplified by the variable gain amplifier 9 according to the amplification factor set by the control unit 4. Then, the timing detection circuit 10 receiving the output of the variable gain amplifier 9 determines the reception of the ultrasonic wave and stops the timer 5. Then, the control unit 4 controls the timer 5
Is obtained from the time information t obtained from (Equation 1).
【０００４】（タイマ５から得た測定時間をｔ、超音波
センサ間の流れ方向の有効距離をＬ、音速をｃ、被測定
流体の流速をｖとする。） ｖ＝（Ｌ／ｔ）−ｃ ・・・（式１） タイミング検知回路１０はコンパレータによって基準電
圧と受信信号を比較するようになっていた。(The measurement time obtained from the timer 5 is t, the effective distance in the flow direction between the ultrasonic sensors is L, the sound velocity is c, and the flow velocity of the fluid to be measured is v.) V = (L / t) − c (Equation 1) The timing detection circuit 10 is configured to compare the reference voltage and the received signal by the comparator.
【０００５】受信信号は、緩やかに立ち上がる波形とな
っており、超音波センサの温度特性や、流速によって受
信信号のレベルは変化する。その前記基準電圧と受信信
号のレベルが適正でないとタイミング検知回路１０の動
作は安定せず測定精度が悪くなる。そこで、可変利得ア
ンプ９の出力を受けているレベル検知回路１１は入力信
号のピークレベルを監視しており、ピーク値が小さいあ
るいは大きい場合に利得制御部８へ出力を行う。利得制
御部８は可変利得アンプ９の増幅率をレベル検知回路１
１からの信号に対応し可変利得アンプ９の出力がほぼ一
定となるように設定する。そして次の受信信号は可変利
得アンプ９で目標の信号レベルへと増幅され、タイミン
グ検知回路１０に与えられる。このようにタイミング検
知回路１０へ与える信号のピークをほぼ一定とすること
によって、受信時間の判定を行うタイミングを安定化し
ていた。[0005] The reception signal has a waveform that rises gently, and the level of the reception signal changes depending on the temperature characteristics and the flow velocity of the ultrasonic sensor. If the reference voltage and the level of the received signal are not appropriate, the operation of the timing detection circuit 10 will not be stable and the measurement accuracy will be poor. Therefore, the level detection circuit 11 receiving the output of the variable gain amplifier 9 monitors the peak level of the input signal, and outputs to the gain control unit 8 when the peak value is small or large. The gain control unit 8 determines the gain of the variable gain amplifier 9 with the level detection circuit 1.
The output of the variable gain amplifier 9 is set so as to be substantially constant in accordance with the signal from No. 1. Then, the next received signal is amplified to a target signal level by the variable gain amplifier 9 and supplied to the timing detection circuit 10. By making the peak of the signal applied to the timing detection circuit 10 substantially constant in this way, the timing for determining the reception time has been stabilized.
【０００６】また、他の測定方法としてタイミング検知
回路１０の判定結果をタイマ５ではなく、遅延回路で一
定時間遅延させた後に駆動回路３に返し、再度送信を行
う場合もあった。このような繰り返し動作を決められた
回数行い時間を測定し、その測定時間を元に（式２）の
計算によって流速を求める方法もあった。As another measurement method, the result of the judgment by the timing detection circuit 10 may be returned to the drive circuit 3 after being delayed by a predetermined time by the delay circuit instead of the timer 5, and then transmitted again. There is also a method in which the repetition operation is performed a predetermined number of times and the time is measured, and based on the measured time, the flow velocity is obtained by calculation of (Equation 2).
【０００７】（遅延回路の遅延時間をＴｄ、繰り返しの
回数をｎ、測定時間をｔｓ、超音波センサ間の流れ方向
の有効距離をＬ、音速をｃ、被測定流体の流速をｖとす
る。） ｖ＝Ｌ／（ｔｓ／ｎ−Ｔｄ）−ｃ ・・・（式２） この方法によれば（式１）の方法に比べ精度よく測定す
ることができる。(The delay time of the delay circuit is Td, the number of repetitions is n, the measurement time is ts, the effective distance in the flow direction between the ultrasonic sensors is L, the sound velocity is c, and the flow velocity of the fluid to be measured is v. ) V = L / (ts / n-Td) -c (Equation 2) According to this method, measurement can be performed with higher accuracy than the method of (Equation 1).
【０００８】また、超音波センサ２と超音波センサ７と
を切り替え、被測定流体の上流から下流と下流から上流
へのそれぞれの伝搬時間を測定し、（式３）より速度ｖ
を求める方法もある。（上流から下流への測定時間時間
をｔ１、下流から上流への測定時間時間をｔ２とする） ｖ＝Ｌ／２（（１／ｔ１）−（１／ｔ２））・・・（式３） この方法によれば音速の変化の影響を受けずに流度を測
定することが出来るので、流速・流量・距離などの測定
に広く利用されている。Further, the ultrasonic sensor 2 and the ultrasonic sensor 7 are switched to measure the respective propagation times of the fluid to be measured from upstream to downstream and from downstream to upstream.
There is also a way to ask. (Measurement time from upstream to downstream is t1, and measurement time from downstream to upstream is t2) v = L / 2 ((1 / t1)-(1 / t2)) (Equation 3) According to this method, the flow rate can be measured without being affected by a change in the speed of sound, so that the method is widely used for measuring flow velocity, flow rate, distance, and the like.
【０００９】[0009]
【発明が解決しようとする課題】しかしながら従来の超
音波流速計では、波形や振幅が変化した場合、タイミン
グ検知しているタイミングがずれるため正確な流量計測
を行うことができず、波形や受信信号の振幅、さらには
タイミング検知回路の信号入力部のオフセットなどの影
響を受けない高精度流速計を実現するという課題があっ
た。However, in the conventional ultrasonic current meter, when the waveform or the amplitude changes, the timing for detecting the timing is shifted, so that accurate flow rate measurement cannot be performed. There is a problem of realizing a high-precision current meter which is not affected by the amplitude of the signal and the offset of the signal input section of the timing detection circuit.
【００１０】また測定流速が早くなると超音波の伝播経
路に渦などの乱れが発生し、受信信号が短い時間で大き
く変動するようになる。その結果可変利得アンプの増幅
率を適正な増幅率に設定できず常に変動するようにな
る。このため大流量での正確な測定が困難であり、早い
流速を精度よく測定するという課題があった。[0010] When the measurement flow velocity increases, turbulence such as eddies occurs in the propagation path of the ultrasonic wave, and the received signal fluctuates greatly in a short time. As a result, the amplification factor of the variable gain amplifier cannot be set to an appropriate amplification factor, and always varies. For this reason, accurate measurement at a large flow rate is difficult, and there is a problem of measuring a fast flow rate with high accuracy.
【００１１】また、遅延回路の遅延時間の精度は測定精
度にそのまま影響を与えるので、高精度の遅延時間をも
つ遅延回路の実現が課題であった。Further, since the accuracy of the delay time of the delay circuit directly affects the measurement accuracy, there has been a problem in realizing a delay circuit having a highly accurate delay time.
【００１２】[0012]
【課題を解決するための手段】本発明は上記課題を解決
するために、駆動回路へ駆動開始位相を１８０°変化さ
せる位相制御信号とを出力する制御部と、他方の前記超
音波センサの受信信号を前記位相制御信号に応じた変化
方向でかつ所定の電位のとき受信タイミングを決定する
タイミング検知回路と、異なる駆動開始位相で測定した
複数の前記タイマの値から前記一対の超音波センサ間の
流速を演算によってもとめる演算部とを備え、位相制御
信号がＬＯのときは、駆動回路が一方の超音波センサを
駆動開始位相０°で駆動しタイミング検知回路はt超音
波受信信号の位相が０°の時の立ち上がりでタイミング
検知する。次に位相制御信号がＨＩのときに前記駆動回
路が前記一方の超音波センサを駆動開始位相を１８０°
で駆動し、受信タイミング検知回路は超音波受信信号の
位相が１８０°の時の立ち下がりでタイミングを検知す
る。In order to solve the above-mentioned problems, the present invention provides a control unit for outputting a phase control signal for changing a driving start phase by 180 ° to a driving circuit, and a receiving unit for receiving the other ultrasonic sensor. A timing detection circuit that determines a reception timing when the signal is in a change direction according to the phase control signal and at a predetermined potential, and between the pair of ultrasonic sensors from a plurality of timer values measured at different drive start phases. When the phase control signal is LO, the drive circuit drives one of the ultrasonic sensors at a drive start phase of 0 °, and the timing detection circuit determines that the phase of the t ultrasonic reception signal is 0. The timing is detected at the rising edge of °. Next, when the phase control signal is HI, the drive circuit drives the one ultrasonic sensor to a drive start phase of 180 °.
, And the reception timing detection circuit detects the timing at the falling edge when the phase of the ultrasonic reception signal is 180 °.
【００１３】２つの受信タイミングの中心は、受信波形
振幅の真の中心（位相０°か１８０°）となるので、振
幅や波形が変化しても変わらない。そこで本装置では位
相制御信号を変え偶数回の測定をし、その測定結果を平
均化することによって、振幅や波形の変化に影響されな
い正確な流速を求めることができる。Since the center of the two reception timings is the true center of the amplitude of the received waveform (phase 0 ° or 180 °), it does not change even if the amplitude or waveform changes. Therefore, the present apparatus changes the phase control signal, performs an even number of measurements, and averages the measurement results to obtain an accurate flow rate that is not affected by changes in amplitude or waveform.
【００１４】[0014]
【発明の実施の形態】本発明の請求項１に係る超音波流
速計は被測定流体中に配置され超音波を送受信する一対
の超音波センサと、一方の前記超音波センサを駆動する
駆動回路と、前記駆動回路を動作させるトリガ信号と前
記駆動回路へ駆動開始位相を１８０°変化させる位相制
御信号とを出力する制御部と、他方の前記超音波センサ
の受信信号を前記位相制御信号に応じた変化方向でかつ
所定の電位のとき受信タイミングを決定するタイミング
検知回路と、少なくとも前記駆動回路による前記超音波
センサの駆動から前記タイミング検知回路が受信タイミ
ングを決定するまでの超音波の伝搬時間を測定するタイ
マと、異なる駆動開始位相で測定した複数の前記タイマ
の値から前記一対の超音波センサ間の流速を演算によっ
てもとめる演算部とを有するものである。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An ultrasonic anemometer according to a first aspect of the present invention includes a pair of ultrasonic sensors arranged in a fluid to be measured for transmitting and receiving ultrasonic waves, and a drive circuit for driving one of the ultrasonic sensors. A control unit that outputs a trigger signal for operating the drive circuit and a phase control signal that changes the drive start phase to the drive circuit by 180 °; and a reception signal of the other ultrasonic sensor according to the phase control signal. The timing detection circuit that determines the reception timing when the change direction is at a predetermined potential, and at least the propagation time of the ultrasonic wave from when the drive circuit drives the ultrasonic sensor to when the timing detection circuit determines the reception timing. A timer for measuring, and a calculation unit for calculating a flow velocity between the pair of ultrasonic sensors from values of the plurality of timers measured at different drive start phases by calculation And it has a.
【００１５】そして制御部は駆動回路へ位相制御信号と
トリガ信号を出力する。トリガ信号をうけた駆動回路は
位相制御信号に応じた駆動開始位相で一方の超音波セン
サを駆動し超音波を送信する。この超音波を他方の超音
波センサで受信し、タイミング検知回路に受信信号を出
力する。タイミング検知回路では位相制御信号に応じた
受信信号の変化で受信検知を行う。トリガ信号の発生と
同時に時間計測を開始したタイマは受信検知と同時に停
止し、超音波の伝播時間を計測する。前記タイマの時間
から前記演算部は（式１）より流速を求める。The control unit outputs a phase control signal and a trigger signal to the drive circuit. The drive circuit receiving the trigger signal drives one of the ultrasonic sensors at a drive start phase according to the phase control signal and transmits an ultrasonic wave. This ultrasonic wave is received by the other ultrasonic sensor, and a reception signal is output to the timing detection circuit. The timing detection circuit detects the reception based on a change in the reception signal according to the phase control signal. The timer which starts time measurement at the same time as the generation of the trigger signal stops at the same time as the reception detection, and measures the propagation time of the ultrasonic wave. From the time of the timer, the calculation unit obtains the flow velocity from (Equation 1).
【００１６】たとえば位相制御信号がＬＯのとき、駆動
回路が一方の超音波センサを駆動開始位相０°で駆動開
始しタイミング検知回路は超音波受信信号の位相が０°
の時の立ち上がりでタイミング検知する。次に位相制御
信号がＨＩのときに前記駆動回路が前記一方の超音波セ
ンサを駆動開始位相を１８０°で駆動開始し、受信タイ
ミング検知回路は超音波受信信号の位相が０°の時の立
ち下がりでタイミングを検知する。For example, when the phase control signal is LO, the drive circuit starts driving one of the ultrasonic sensors at a drive start phase of 0 °, and the timing detection circuit determines that the phase of the ultrasonic reception signal is 0 °.
The timing is detected at the rising edge of. Next, when the phase control signal is HI, the drive circuit starts driving the one ultrasonic sensor at a drive start phase of 180 °, and the reception timing detection circuit starts the operation when the phase of the ultrasonic reception signal is 0 °. The timing is detected by falling.
【００１７】図２に示すように２つの受信タイミングの
中心は、受信波形振幅の真の中心（位相０°か１８０
°）となるので、振幅や波形が変化しても変わらない。
そこで本装置では位相制御信号を変え２回の測定をし、
その測定結果を平均することによって、振幅や波形の変
化に影響されない正確な受信タイミングの検知をおこな
い、正確に測定する事ができる。As shown in FIG. 2, the center of the two reception timings is the true center of the reception waveform amplitude (phase 0 ° or 180 °).
°), so it does not change even if the amplitude or waveform changes.
Therefore, this device changes the phase control signal and performs two measurements.
By averaging the measurement results, it is possible to detect an accurate reception timing that is not affected by changes in amplitude or waveform, and to perform accurate measurement.
【００１８】本発明の請求項２に係る超音波流速計は被
測定流体中に配置され超音波を送受信する一対の超音波
センサと、一方の前記超音波センサを駆動する駆動回路
と、前記駆動回路を動作させるトリガ信号を出力する制
御部と、他方の前記超音波センサの受信信号を前記位相
制御信号に応じた変化方向でかつ所定の電位のとき受信
タイミングを決定するタイミング検知回路と、前記タイ
ミング検知回路の出力を前記駆動回路のトリガ信号とし
て前記駆動回路へ出力しかつその回数を計測し所定の回
数で動作を停止する繰り返し回路と、前記駆動回路へ駆
動開始位相を180°変化させる位相制御信号を前記繰り
返し回路の計測する繰り返し回数に応じて変え出力する
位相制御回路と、少なくとも前記駆動回路による前記超
音波センサの駆動から前記繰り返し回路の動作停止まで
の超音波の伝搬時間を測定するタイマと、前記タイマの
値から前記一対の超音波センサ間の流速を演算によって
もとめる演算部とを有するものである。According to a second aspect of the present invention, there is provided an ultrasonic current meter arranged in a fluid to be measured for transmitting and receiving ultrasonic waves, a driving circuit for driving one of the ultrasonic sensors, and the driving circuit. A control unit that outputs a trigger signal for operating a circuit, a timing detection circuit that determines a reception timing when a reception signal of the other ultrasonic sensor is in a change direction according to the phase control signal and at a predetermined potential, A repetition circuit that outputs an output of a timing detection circuit to the drive circuit as a trigger signal of the drive circuit and measures the number of times, and stops operation at a predetermined number of times; and a phase that changes the drive start phase to the drive circuit by 180 °. A phase control circuit that changes and outputs a control signal according to the number of repetitions measured by the repetition circuit, and whether the ultrasonic sensor is driven by at least the drive circuit Wherein a timer for measuring the ultrasonic wave propagation time until the operation stop of the repeating circuit, and has a the finding from the value of the timer by computing the flow rate between the pair of ultrasonic sensors calculation unit.
【００１９】そして、前記タイミング検知回路の出力を
前記駆動回路に出力し再度前記超音波センサを駆動する
ことにより、超音波の伝搬を前記繰り返し回路にあらか
じめ設定した回数行い、その合計の時間を前記タイマで
測定する構成となっている。この複数回超音波を伝播さ
せる中で、前記繰り返し回路がその繰り返し回数に応じ
て位相制御信号を前記駆動回路と前記タイミング検知回
路へ出力する。前記駆動回路は位相制御信号によって駆
動位相を変更し送信し、タイミング検知回路も位相制御
信号に対応した受信タイミングを検知する。このため２
回の測定を行ない演算によって平均化する必要がなく、
正確な流速を求めることができる。Then, by outputting the output of the timing detection circuit to the drive circuit and driving the ultrasonic sensor again, ultrasonic waves are propagated in the repetition circuit a preset number of times, and the total time is calculated by the total time. It is configured to measure with a timer. During the propagation of the ultrasonic wave a plurality of times, the repetition circuit outputs a phase control signal to the drive circuit and the timing detection circuit according to the number of repetitions. The drive circuit changes the drive phase according to the phase control signal and transmits the same, and the timing detection circuit detects the reception timing corresponding to the phase control signal. Therefore 2
There is no need to perform measurements and average by calculation,
An accurate flow rate can be determined.
【００２０】本発明の請求項３に係る超音波流速計は被
測定流体中に配置され超音波を送受信する一対の超音波
センサと、一方の超音波センサを駆動する駆動回路と、
他方の超音波センサで受信した受信信号を設定された増
幅率で増幅する可変利得アンプと、前記可変利得アンプ
の出力から受信タイミングを判定するタイミング検知回
路と、前記可変利得アンプの出力に対応した信号を出力
するレベル検知回路と、前記レベル検知回路の出力を受
け前記可変利得アンプの出力をほぼ一定に制御する利得
制御部と、超音波の伝播時間を測定するタイマと、前記
タイマから得たデータをもとに流速を演算によって求め
る演算部とを備え、前記演算部によって求めた流速が所
定の流速以上になったときに、前記利得制御回路が前記
可変利得アンプの増幅率を所定の増幅率に固定する。An ultrasonic current meter according to a third aspect of the present invention includes a pair of ultrasonic sensors arranged in a fluid to be measured for transmitting and receiving ultrasonic waves, a driving circuit for driving one ultrasonic sensor,
A variable gain amplifier that amplifies a reception signal received by the other ultrasonic sensor at a set amplification factor, a timing detection circuit that determines reception timing from an output of the variable gain amplifier, and an output of the variable gain amplifier. A level detection circuit that outputs a signal, a gain control unit that receives the output of the level detection circuit and controls the output of the variable gain amplifier to be substantially constant, a timer that measures the propagation time of the ultrasonic wave, and a timer that is obtained from the timer. An arithmetic unit for calculating the flow rate based on the data, wherein when the flow rate obtained by the arithmetic unit is equal to or higher than a predetermined flow rate, the gain control circuit increases the amplification factor of the variable gain amplifier by a predetermined amount. Fix to the rate.
【００２１】そして、流速が早くなると前記可変利得ア
ンプの増幅率を所定の増幅率に固定するので、流れの変
化による乱れや渦によって、増幅率が変化することがな
く安定した測定を行うことができる。このため、流速計
測を安定して精度良く行うことができる。When the flow velocity increases, the gain of the variable gain amplifier is fixed at a predetermined gain. Therefore, stable measurement can be performed without changing the gain due to disturbance or eddy due to a change in flow. it can. For this reason, the flow velocity measurement can be performed stably and accurately.
【００２２】本発明の請求項４に係る超音波流速計は被
測定流体中に配置され超音波を送受信する一対の超音波
センサと、一方の超音波センサを駆動する駆動回路と、
他方の超音波センサで受信した受信信号を設定された増
幅率で増幅する可変利得アンプと、前記可変利得アンプ
の出力から受信タイミングを判定するタイミング検知回
路と、超音波の伝播時間を測定するタイマと、前記タイ
マから得たデータをもとに流速を演算によって求める演
算部とを有するものである。An ultrasonic current meter according to a fourth aspect of the present invention includes a pair of ultrasonic sensors arranged in a fluid to be measured for transmitting and receiving ultrasonic waves, a driving circuit for driving one ultrasonic sensor,
A variable gain amplifier that amplifies a reception signal received by the other ultrasonic sensor at a set amplification factor, a timing detection circuit that determines reception timing from an output of the variable gain amplifier, and a timer that measures the propagation time of the ultrasonic wave And a calculation unit for calculating the flow velocity based on the data obtained from the timer.
【００２３】そして、前記利得制御部が前記演算部で求
めた流速に応じて前記可変利得回路の増幅率を制御する
ので、早い流速で生じる渦などによる受信信号の低下
や、超音波の干渉によって起こる受信信号の変動を確実
に補正し正確な流速測定を行うことができる。The gain control section controls the gain of the variable gain circuit in accordance with the flow velocity obtained by the operation section. Variations in the received signal that occur can be reliably corrected, and accurate flow velocity measurement can be performed.
【００２４】本発明の請求項５に係る超音波流速計は被
測定流体中に配置され超音波を送受信する一対の超音波
センサと、一方の超音波センサを駆動する駆動回路と、
他方の超音波センサで受信した受信信号を設定された増
幅率で増幅する可変利得アンプと、前記可変利得アンプ
の出力から受信タイミングを判定するタイミング検知回
路と、超音波の伝播時間を測定するタイマと、前記タイ
マから得たデータをもとに流速を演算によって求める演
算部と、前記可変利得アンプの出力に対応した信号を出
力するレベル検知回路と、前記レベル検知回路の出力を
受け前記可変利得アンプの出力をほぼ一定に制御する利
得制御部とを有するものである。According to a fifth aspect of the present invention, there is provided an ultrasonic current meter arranged in a fluid to be measured, for transmitting and receiving ultrasonic waves, a driving circuit for driving one ultrasonic sensor,
A variable gain amplifier that amplifies a reception signal received by the other ultrasonic sensor at a set amplification factor, a timing detection circuit that determines reception timing from an output of the variable gain amplifier, and a timer that measures the propagation time of the ultrasonic wave An arithmetic unit for calculating a flow velocity based on data obtained from the timer, a level detection circuit that outputs a signal corresponding to the output of the variable gain amplifier, and the variable gain receiving the output of the level detection circuit. And a gain control unit for controlling the output of the amplifier to be substantially constant.
【００２５】そして前記レベル検知回路の出力変動が所
定の値以上になったときに、前記利得制御部が前記演算
部によって求めた流速に応じて前記可変利得回路の増幅
率を制御するので、流速の変動によって発生する渦や、
大流量で生じる渦などによる受信信号の低下や、超音波
の干渉によって起こる受信信号の変動を確実に補正し正
確な流速測定を行うことができる。When the output fluctuation of the level detection circuit becomes equal to or more than a predetermined value, the gain control section controls the gain of the variable gain circuit in accordance with the flow rate obtained by the arithmetic section. Vortices generated by fluctuations in
It is possible to accurately correct a decrease in the received signal due to a vortex or the like generated at a large flow rate, and a fluctuation in the received signal caused by interference of ultrasonic waves, and perform accurate flow velocity measurement.
【００２６】本発明の請求項６に係る超音波流速計は前
記利得制御部が前記レベル検知回路出力の最大値と最小
値より平均値を求め増幅率を制御するので、流速が早い
場合に伝播経路に発生する渦などによって受信信号が安
定しないときでも、適正な受信感度に前記可変利得アン
プの増幅率を設定するので、流速が早い場合でも安定し
た測定を精度良く測定できる。In the ultrasonic anemometer according to a sixth aspect of the present invention, since the gain control unit obtains an average value from the maximum value and the minimum value of the output of the level detection circuit and controls the amplification factor, it propagates when the flow velocity is high. Even when the received signal is not stable due to a vortex or the like generated in the path, since the gain of the variable gain amplifier is set to an appropriate reception sensitivity, stable measurement can be accurately performed even when the flow velocity is high.
【００２７】本発明の請求項７に係る超音波流速計は
被測定流体中に配置され超音波を送受信する一対の超音
波センサと、一方の前記超音波センサを駆動する駆動回
路と、前記駆動回路を動作させるトリガ信号を出力する
制御部と、他方の前記超音波センサ出力を受け受信タイ
ミングを決定するタイミング検知回路と、前記タイミン
グ検知回路の出力を所定の遅延時間遅れて前記駆動回路
のトリガ信号として出力する遅延回路と、超音波の送受
信そして遅延回路で遅延時間の後に再度超音波の送受信
を繰り返すという動作回数を計測し所定の回数で動作を
停止する繰り返し回路と、少なくとも前記駆動回路によ
る前記超音波センサの駆動から前記繰り返し回路の動作
停止までの超音波の伝搬時間を測定するタイマと、前記
タイマの値から前記一対の超音波センサ間の流速を演算
によってもとめる演算部とを有するものである。An ultrasonic current meter according to claim 7 of the present invention is
A pair of ultrasonic sensors arranged in the fluid under measurement for transmitting and receiving ultrasonic waves, a driving circuit for driving one of the ultrasonic sensors, a control unit for outputting a trigger signal for operating the driving circuit, and the other of the other A timing detection circuit that receives an ultrasonic sensor output and determines a reception timing; a delay circuit that outputs the output of the timing detection circuit as a trigger signal of the drive circuit with a predetermined delay time delay; A repetition circuit for measuring the number of operations of repeating transmission and reception of ultrasonic waves again after the delay time and stopping the operation at a predetermined number of times, A timer for measuring the propagation time of the sound wave, and a flow velocity between the pair of ultrasonic sensors is calculated from a value of the timer. Those having a calculation unit.
【００２８】そして前記遅延回路を測定の直前に所定時
間動作させ、前記遅延回路の動作初期の不安定な動作を
事前に行い、計測時の動作を安定にすることができるの
で、安定した時間測定ができ、正確な流速測定を行うこ
とができる。The delay circuit is operated for a predetermined time immediately before the measurement, and the unstable operation at the initial stage of the operation of the delay circuit is performed in advance, and the operation at the time of measurement can be stabilized. And accurate flow velocity measurement can be performed.
【００２９】[0029]
【実施例】以下、本発明の実施例について図面を用いて
説明する。Embodiments of the present invention will be described below with reference to the drawings.
【００３０】（実施例１）図１は本発明の実施例１の超
音波流速計のブロック図である。また図２は受信信号の
受信タイミングをあらわす図である。(Embodiment 1) FIG. 1 is a block diagram of an ultrasonic velocimeter according to Embodiment 1 of the present invention. FIG. 2 is a diagram showing the reception timing of the reception signal.
【００３１】図１において、本発明の超音波流速計は流
路１と、被測定流体中に配置され超音波を送受信する一
対の超音波センサ１２、１３と、超音波センサ２を駆動
する駆動回路１４と、駆動回路１４を動作させるトリガ
信号と駆動回路１４の駆動開始位相を１８０°変化させ
る位相制御信号とを出力する制御部１５と、他方の超音
波センサである超音波センサ１３の受信信号を前記位相
制御信号に応じ立ち上がりあるいは立ち下がりでなおか
つ所定の電位のとき受信タイミングを決定するタイミン
グ検知回路１６と、少なくとも駆動回路１４による超音
波センサ１２の駆動からタイミング検知回路１６が受信
タイミングを決定するまでの超音波の伝搬時間を測定す
るタイマ１７と、異なる駆動開始位相で測定した複数の
タイマ１７の値から超音波センサ間の流速を演算によっ
てもとめる演算部１８とを有するものである。Referring to FIG. 1, the ultrasonic anemometer of the present invention comprises a flow path 1, a pair of ultrasonic sensors 12 and 13 arranged in a fluid to be measured and transmitting and receiving ultrasonic waves, and a drive for driving the ultrasonic sensors 2. A circuit 14, a control unit 15 for outputting a trigger signal for operating the drive circuit 14 and a phase control signal for changing the drive start phase of the drive circuit 14 by 180 °, and reception of the ultrasonic sensor 13 as the other ultrasonic sensor The timing detection circuit 16 determines the reception timing when the signal rises or falls according to the phase control signal and has a predetermined potential, and the timing detection circuit 16 determines the reception timing from at least the driving of the ultrasonic sensor 12 by the drive circuit 14. The timer 17 measures the propagation time of the ultrasonic wave until it is determined, and the values of the timers 17 measured at different driving start phases are different. Those having a computing unit 18 obtains by calculating the flow rate between the ultrasonic sensor.
【００３２】そして制御部１５は駆動回路１４へ位相制
御信号とトリガ信号を出力する。トリガ信号をうけた駆
動回路１４は位相制御信号に応じた駆動開始位相で超音
波センサ１２を駆動し超音波を送信する。この超音波を
超音波センサ１３で受信し、タイミング検知回路１６に
受信信号を出力する。タイミング検知回路１６では位相
制御信号に応じ立ち上がりあるいは立ち下がりで受信検
知を行う。トリガ信号の発生と同時に時間計測を開始し
たタイマ１７は受信検知と同時に停止し、超音波の伝播
時間を計測する。タイマ１７の時間から演算部１８は
（式１）より流速を求める。The control unit 15 outputs a phase control signal and a trigger signal to the drive circuit 14. The drive circuit 14 having received the trigger signal drives the ultrasonic sensor 12 at a drive start phase according to the phase control signal and transmits an ultrasonic wave. The ultrasonic wave is received by the ultrasonic sensor 13 and a reception signal is output to the timing detection circuit 16. The timing detection circuit 16 detects reception at the rise or fall according to the phase control signal. The timer 17 which starts time measurement at the same time as the generation of the trigger signal stops at the same time as the reception detection, and measures the propagation time of the ultrasonic wave. Based on the time of the timer 17, the calculation unit 18 obtains the flow velocity from (Equation 1).
【００３３】たとえば位相制御信号がＬＯのとき、駆動
回路１４が超音波センサ１２を駆動開始位相０°で駆動
開始しタイミング検知回路１６は超音波受信信号の位相
が０°の時の立ち上がりでタイミング検知する。次に位
相制御信号がＨＩのときに前記駆動回路１４が超音波セ
ンサ１２を駆動開始位相を１８０°で駆動開始し、受信
タイミング検知回路１６は超音波受信信号の位相が０°
の時の立ち下がりでタイミングを検知する。For example, when the phase control signal is LO, the driving circuit 14 starts driving the ultrasonic sensor 12 at a driving start phase of 0 °, and the timing detecting circuit 16 sets the timing at the rising edge when the phase of the ultrasonic receiving signal is 0 °. Detect. Next, when the phase control signal is HI, the drive circuit 14 starts driving the ultrasonic sensor 12 at a drive start phase of 180 °, and the reception timing detection circuit 16 determines that the phase of the ultrasonic reception signal is 0 °.
The timing is detected at the falling edge of the time.
【００３４】図２に示すように２つの受信タイミングの
中心は、受信波形振幅の真の中心（位相０°か１８０
°）となるので、振幅や波形が変化しても変わらない。
そこで本装置では位相制御信号を変え２回の測定をし、
その測定結果を平均することによって、振幅や波形の変
化あるいはタイミング検知回路のもつオフセットに影響
されない正確な受信タイミングの検知をおこない、正確
な測定を行う事ができる。As shown in FIG. 2, the center of the two reception timings is the true center of the reception waveform amplitude (phase 0 ° or 180 °).
°), so it does not change even if the amplitude or waveform changes.
Therefore, this device changes the phase control signal and performs two measurements.
By averaging the measurement results, it is possible to detect an accurate reception timing which is not affected by a change in amplitude or waveform or an offset of a timing detection circuit, and to perform an accurate measurement.
【００３５】（実施例２）図３は本発明の実施例２の超
音波流速計のブロック図である。(Embodiment 2) FIG. 3 is a block diagram of an ultrasonic current meter according to Embodiment 2 of the present invention.
【００３６】図３において、本発明の超音波流速計流路
１と、被測定流体中に配置され超音波を送受信する超音
波センサ１２、１３と、超音波センサ１２を駆動する駆
動回路１４と、駆動回路１４を動作させるトリガ信号を
出力する制御部１５と、超音波センサ１３の受信信号を
前記位相制御信号に応じた変化方向でかつ所定の電位の
とき受信タイミングを決定するタイミング検知回路１６
と、タイミング検知回路１６の出力を駆動回路１４のト
リガ信号として駆動回路１４へ出力しかつその回数を計
測し所定の回数で動作を停止する繰り返し回路１９と、
駆動回路１４へ駆動開始位相を180°変化させる位相制
御信号を前記繰り返し回路１９の計測する繰り返し回数
に応じて変え出力する位相制御回路２０と、少なくとも
駆動回路１４による超音波センサの駆動から前記繰り返
し回路の動作停止までの超音波の伝搬時間を測定するタ
イマ１７と、前記タイマ１７の値から超音波センサ間の
流速を演算によってもとめる演算部１８とを有するもの
である。In FIG. 3, the ultrasonic flowmeter channel 1 of the present invention, ultrasonic sensors 12 and 13 arranged in the fluid to be measured for transmitting and receiving ultrasonic waves, and a driving circuit 14 for driving the ultrasonic sensor 12 are shown. A control unit 15 for outputting a trigger signal for operating the drive circuit 14, and a timing detection circuit 16 for determining the reception timing when the reception signal of the ultrasonic sensor 13 is in a change direction according to the phase control signal and at a predetermined potential.
A repetition circuit 19 that outputs the output of the timing detection circuit 16 to the drive circuit 14 as a trigger signal of the drive circuit 14, measures the number of times, and stops the operation at a predetermined number of times;
A phase control circuit 20 for changing and outputting a phase control signal for changing the driving start phase to the drive circuit 180 by 180 ° according to the number of repetitions measured by the repetition circuit 19; It has a timer 17 for measuring the propagation time of the ultrasonic wave until the operation of the circuit is stopped, and a calculation unit 18 for calculating the flow velocity between the ultrasonic sensors from the value of the timer 17 by calculation.
【００３７】そして、タイミング検知回路１６の出力を
駆動回路１４に出力し再度前記超音波センサ１２を駆動
することにより、超音波の伝搬を前記繰り返し回路１９
にあらかじめ設定した回数行い、その合計の時間をタイ
マ１７で測定する構成となっている。この複数回超音波
を伝播させる中で、位相制御回路２０が繰り返し回数に
応じて位相制御信号を駆動回路１４とタイミング検知回
路１６へ出力する。駆動回路１４は位相制御信号によっ
て駆動位相を変更し送信し、タイミング検知回路１６も
位相制御信号に対応した受信タイミングを検知する。こ
のため２回の測定を行ない演算によって平均化する必要
がなく、正確な流速を求めることができる。、 （実施例３）図４は本発明の実施例３の超音波流速計の
ブロック図である。Then, the output of the timing detection circuit 16 is output to the drive circuit 14 and the ultrasonic sensor 12 is driven again, so that the propagation of ultrasonic waves is repeated in the repetition circuit 19.
And the timer 17 measures the total time. During the propagation of the ultrasonic wave a plurality of times, the phase control circuit 20 outputs a phase control signal to the drive circuit 14 and the timing detection circuit 16 according to the number of repetitions. The drive circuit 14 changes the drive phase according to the phase control signal and transmits the same, and the timing detection circuit 16 also detects the reception timing corresponding to the phase control signal. For this reason, it is not necessary to perform two measurements and to average them by calculation, and it is possible to obtain an accurate flow velocity. (Embodiment 3) FIG. 4 is a block diagram of an ultrasonic current meter according to Embodiment 3 of the present invention.
【００３８】図４において、本発明の超音波流速計は流
路１と、被測定流体中に配置され超音波を送受信するの
超音波センサ１２、１３と、超音波センサ１２を駆動す
る駆動回路１４と、超音波センサ１３で受信した受信信
号を設定された増幅率で増幅する可変利得アンプ２１
と、可変利得アンプ２１の出力から受信タイミングを判
定するタイミング検知回路１６と、可変利得アンプ２１
の出力に対応した信号を出力するレベル検知回路２２
と、レベル検知回路２２の出力を受け可変利得アンプ２
１の出力をほぼ一定に制御する利得制御回路２３と、超
音波の伝播時間を測定するタイマ１７と、タイマ１７か
ら得たデータをもとに流速を演算によって求める演算部
１８とを備え、演算部１８によって求めた流速が所定の
流速以上になったときに、利得制御回路２３が可変利得
アンプ２１の増幅率を所定の増幅率に固定する。Referring to FIG. 4, the ultrasonic anemometer of the present invention comprises a flow path 1, ultrasonic sensors 12 and 13 arranged in a fluid to be measured for transmitting and receiving ultrasonic waves, and a drive circuit for driving the ultrasonic sensor 12. 14 and a variable gain amplifier 21 for amplifying a reception signal received by the ultrasonic sensor 13 at a set amplification factor
A timing detection circuit 16 for determining a reception timing from an output of the variable gain amplifier 21;
Level detection circuit 22 that outputs a signal corresponding to the output of
And the variable gain amplifier 2 receiving the output of the level detection circuit 22
1 is provided with a gain control circuit 23 for controlling the output of the control signal 1 substantially constant, a timer 17 for measuring the propagation time of the ultrasonic wave, and a calculation unit 18 for calculating the flow velocity based on the data obtained from the timer 17. When the flow rate obtained by the section 18 is equal to or higher than the predetermined flow rate, the gain control circuit 23 fixes the gain of the variable gain amplifier 21 to the predetermined gain.
【００３９】そして、流速が早くなると可変利得アンプ
２１の増幅率を所定の増幅率に固定するので、流れの変
化による乱れや渦による受信信号のふらつきによって増
幅率が変化することがなく安定した測定を行うことがで
きる。このため、早い流速の計測を安定して精度良く行
うことができる。When the flow velocity increases, the gain of the variable gain amplifier 21 is fixed to a predetermined gain, so that the gain is not changed by disturbance due to a change in the flow or fluctuation of the received signal due to eddy and stable measurement. It can be performed. For this reason, measurement of a fast flow velocity can be performed stably and accurately.
【００４０】（実施例４）図５は本発明の実施例４の超
音波流速計のブロック図である。(Embodiment 4) FIG. 5 is a block diagram of an ultrasonic velocimeter according to Embodiment 4 of the present invention.
【００４１】図５において、本発明の超音波流速計は流
路１と、被測定流体中に配置されたの超音波センサ１
２、１３と、超音波センサ１２を駆動する駆動回路１４
と、超音波センサ１３で受信した受信信号を設定された
増幅率で増幅する可変利得アンプ２１と、可変利得アン
プ２１の出力から受信タイミングを判定するタイミング
検知回路１６と、超音波の伝播時間を測定するタイマ１
７と、タイマから得たデータをもとに流速を演算によっ
て求める演算部１８と、可変利得アンプ２１の出力に対
応した信号を出力するレベル検知回路２２と、レベル検
知回路２２の出力を受け可変利得アンプ２１の出力をほ
ぼ一定に制御する利得制御回路２３とを有するものであ
る。Referring to FIG. 5, an ultrasonic current meter according to the present invention includes a flow path 1 and an ultrasonic sensor 1 disposed in a fluid to be measured.
2, 13 and a drive circuit 14 for driving the ultrasonic sensor 12
A variable gain amplifier 21 that amplifies a reception signal received by the ultrasonic sensor 13 at a set amplification factor; a timing detection circuit 16 that determines reception timing from an output of the variable gain amplifier 21; Timer 1 to measure
7, a calculation unit 18 for calculating the flow velocity based on the data obtained from the timer, a level detection circuit 22 for outputting a signal corresponding to the output of the variable gain amplifier 21, and an output from the level detection circuit 22 And a gain control circuit 23 for controlling the output of the gain amplifier 21 to be substantially constant.
【００４２】そして利得制御回路２３が前記演算部で求
めた流速に応じて可変利得回路２１の増幅率を制御する
ので、早い流速で生じる渦などによる受信信号の低下
や、超音波の干渉によって起こる受信信号の変動を確実
に補正し正確な流速測定を行うことができる。Since the gain control circuit 23 controls the amplification factor of the variable gain circuit 21 in accordance with the flow velocity obtained by the operation unit, the reception signal decreases due to a vortex or the like generated at a high flow velocity or the ultrasonic wave interferes. Fluctuations in the received signal can be reliably corrected and accurate flow velocity measurement can be performed.
【００４３】（実施例５）図６は本発明の実施例５の超
音波流速計のブロック図である。(Embodiment 5) FIG. 6 is a block diagram of an ultrasonic velocimeter according to Embodiment 5 of the present invention.
【００４４】図６において、本発明の超音波流速計は流
路１と、被測定流体中に配置され超音波を送受信する超
音波センサ１２、１３と、超音波センサ１２を駆動する
駆動回路１４と、超音波センサ１３で受信した受信信号
を設定された増幅率で増幅する可変利得アンプ２１と、
可変利得アンプ２１の出力から受信タイミングを判定す
るタイミング検知回路１６と、超音波の伝播時間を測定
するタイマ１７と、タイマ１７から得たデータをもとに
流速を演算によって求める演算部１８と、可変利得アン
プ２１の出力に対応した信号を出力するレベル検知回路
２２と、レベル検知回路２２の出力を受け可変利得アン
プ２１の出力をほぼ一定に制御する利得制御回路２３と
を有するものである。Referring to FIG. 6, the ultrasonic anemometer according to the present invention comprises a flow path 1, ultrasonic sensors 12 and 13 arranged in a fluid to be measured for transmitting and receiving ultrasonic waves, and a drive circuit 14 for driving the ultrasonic sensors 12. A variable gain amplifier 21 that amplifies a reception signal received by the ultrasonic sensor 13 at a set amplification factor;
A timing detection circuit 16 for determining a reception timing from the output of the variable gain amplifier 21, a timer 17 for measuring the propagation time of the ultrasonic wave, and a calculation unit 18 for calculating a flow velocity based on data obtained from the timer 17, It has a level detection circuit 22 that outputs a signal corresponding to the output of the variable gain amplifier 21, and a gain control circuit 23 that receives the output of the level detection circuit 22 and controls the output of the variable gain amplifier 21 to be substantially constant.
【００４５】そしてレベル検知回路２２の出力変動が所
定の値以上になったときに、利得制御回路２３が演算部
１８によって求めた流速に応じて可変利得アンプ２１の
増幅率を制御するので、流速の変動によって発生する渦
や、大流量で生じる渦などによる受信信号の低下や、超
音波の干渉によって起こる受信信号の変動を確実に補正
し正確な流速測定を行うことができる。When the output fluctuation of the level detection circuit 22 exceeds a predetermined value, the gain control circuit 23 controls the amplification factor of the variable gain amplifier 21 in accordance with the flow velocity obtained by the arithmetic unit 18. The vortex generated due to the fluctuation of the flow rate, the reduction in the received signal due to the vortex generated at a large flow rate, and the fluctuation of the received signal caused by the interference of the ultrasonic wave can be reliably corrected and the flow velocity can be accurately measured.
【００４６】また、利得制御回路が前記レベル検知回路
出力の最大値と最小値から平均値を求め増幅率を制御す
るので、流速が早い場合に伝播経路に発生する渦などに
よって受信信号が安定しないときでも、適正な受信感度
に前記可変利得アンプの増幅率を設定するので、流速が
早い場合でも安定した測定を精度良く測定できる。Further, since the gain control circuit calculates the average value from the maximum value and the minimum value of the output of the level detection circuit and controls the amplification factor, the received signal is not stabilized due to a vortex generated in the propagation path when the flow velocity is high. Even in such a case, since the gain of the variable gain amplifier is set to an appropriate reception sensitivity, stable measurement can be accurately performed even when the flow velocity is high.
【００４７】（実施例６）図７は本発明の実施例６の超
音波流速計のブロック図である。(Embodiment 6) FIG. 7 is a block diagram of an ultrasonic velocimeter according to Embodiment 6 of the present invention.
【００４８】図７において、本発明の超音波流速計は流
路１と、被測定流体中に配置され超音波を送受信する超
音波センサ１２、１３と、前記超音波センサ１２を駆動
する駆動回路１４と、駆動回路１４を動作させるトリガ
信号を出力する制御部１５と、超音波センサ１３の受信
信号を受け受信タイミングを決定するタイミング検知回
路１６と、タイミング検知回路１６の出力を所定の遅延
時間遅れて駆動回路１４のトリガ信号として出力する遅
延回路２４と、超音波の送受信そして遅延回路２４で遅
延時間の後に再度超音波の送受信を繰り返すという動作
回数を計測し所定の回数で動作を停止する繰り返し回路
１９と、少なくとも駆動回路１４による超音波センサ１
２の駆動開始から前記繰り返し回路１９の動作停止まで
の超音波の伝搬時間を測定するタイマ１７と、前記タイ
マ１７の値から前記一対の超音波センサ間の流速を演算
によってもとめる演算部１８とを有するものである。In FIG. 7, the ultrasonic anemometer according to the present invention comprises a flow path 1, ultrasonic sensors 12 and 13 arranged in a fluid to be measured for transmitting and receiving ultrasonic waves, and a drive circuit for driving the ultrasonic sensors 12. 14, a control unit 15 for outputting a trigger signal for operating the drive circuit 14, a timing detection circuit 16 for receiving a reception signal of the ultrasonic sensor 13, and determining a reception timing, and an output of the timing detection circuit 16 for a predetermined delay time. A delay circuit 24 that outputs a trigger signal of the drive circuit 14 with a delay, transmission / reception of ultrasonic waves, and the delay circuit 24 count the number of operations of repeating transmission / reception of ultrasonic waves after a delay time, and stop operation at a predetermined number of times. Ultrasonic sensor 1 by repetition circuit 19 and at least drive circuit 14
A timer 17 for measuring the propagation time of the ultrasonic wave from the start of driving of the second to the stop of the operation of the iterative circuit 19, and a calculation unit 18 for calculating the flow velocity between the pair of ultrasonic sensors from the value of the timer 17 by calculation. Have
【００４９】そして遅延回路２４を測定の直前に所定時
間動作させ、遅延回路２４の動作初期の不安定な動作を
事前に行い、計測時の動作を安定にすることができるの
で、安定した時間測定ができ、正確な流速測定を行うこ
とができる。Then, the delay circuit 24 is operated for a predetermined time immediately before the measurement, and the unstable operation at the initial stage of the operation of the delay circuit 24 is performed in advance, and the operation at the time of measurement can be stabilized. And accurate flow velocity measurement can be performed.
【００５０】[0050]
【発明の効果】以上の説明から明らかのように本発明の
請求項１に係る超音波流速計は測定誤差が真値に対して
正と負に発生し、その測定結果を平均することによって
誤差をキャンセルし真値を求めているので、振幅や波形
の変化に影響されない正確な受信タイミングの検知を行
い、正確な測定を行うことができる。As is apparent from the above description, in the ultrasonic anemometer according to the first aspect of the present invention, a measurement error occurs positively and negatively with respect to a true value, and the error is obtained by averaging the measurement results. Is canceled and the true value is obtained, accurate detection of the reception timing not affected by changes in the amplitude or waveform can be performed, and accurate measurement can be performed.
【００５１】また、請求項２に係る超音波流速計は繰り
返し回路がその繰り返し回数に応じて位相制御信号を前
記駆動回路と前記タイミング検知回路へ出力し、駆動回
路は位相制御信号によって駆動位相を変更し送信し、タ
イミング検知回路も位相制御信号に対応した受信タイミ
ングを検知するので２回の測定を行ない演算によって平
均化する必要がなく、正確な流速を求めることができる
という効果がある。According to a second aspect of the present invention, in the ultrasonic flowmeter, the repetition circuit outputs a phase control signal to the drive circuit and the timing detection circuit according to the number of repetitions, and the drive circuit changes the drive phase by the phase control signal. Since the timing is changed and transmitted, and the timing detection circuit also detects the reception timing corresponding to the phase control signal, there is no need to perform two measurements and average the values by calculation, and there is an effect that an accurate flow velocity can be obtained.
【００５２】また、請求項４に係る超音波流速計は利得
制御部が演算部で求めた流速に応じて前記可変利得回路
の増幅率を制御するので、早い流速で生じる渦などによ
る受信信号の低下や、超音波の干渉によって起こる受信
信号の変動を確実に補正し正確な流速測定を行うことが
できるという効果がある。Further, in the ultrasonic flowmeter according to the fourth aspect, the gain control section controls the amplification factor of the variable gain circuit in accordance with the flow rate obtained by the operation section, so that the reception signal due to a vortex generated at a high flow rate can be obtained. There is an effect that the fluctuation of the received signal caused by the decrease or the interference of the ultrasonic wave can be surely corrected, and the accurate flow velocity measurement can be performed.
【００５３】また、請求項５に係る超音波流速計はレベ
ル検知回路の出力変動が所定の値以上になったときに、
演算部によって求めた流速に応じて前記可変利得回路の
増幅率を制御するので、流速の変動によって発生する渦
や、大流量で生じる渦などによる受信信号の低下や、超
音波の干渉によって起こる受信信号の変動を確実に補正
し正確な流速測定を行うことができるという効果があ
る。The ultrasonic anemometer according to the fifth aspect is configured such that when the output fluctuation of the level detection circuit exceeds a predetermined value,
Since the amplification factor of the variable gain circuit is controlled in accordance with the flow velocity obtained by the arithmetic unit, the reception signal decreases due to a vortex generated due to a fluctuation in the flow velocity, a vortex generated at a large flow rate, or a reception generated due to ultrasonic interference. There is an effect that the fluctuation of the signal can be surely corrected and the flow velocity can be accurately measured.
【００５４】また、請求項６に係る超音波流速計は利得
制御部が前記レベル検知回路出力の最大値と最小値より
平均値を求め増幅率を制御するので、流速が早い場合に
伝播経路に発生する渦などによって受信信号が安定しな
いときでも、適正な受信感度に前記可変利得アンプの増
幅率を設定するので、流速が早い場合でも安定した測定
を精度良く測定できるという効果がある。Further, in the ultrasonic anemometer according to the sixth aspect, the gain control section obtains an average value from the maximum value and the minimum value of the level detection circuit output and controls the amplification factor. Even when the received signal is not stable due to the generated vortex or the like, the gain of the variable gain amplifier is set to an appropriate reception sensitivity, so that there is an effect that stable measurement can be accurately performed even when the flow velocity is high.
【００５５】また、請求項７に係る超音波流速計は遅延
回路を測定の直前に所定時間動作させ、前記遅延回路の
動作初期の不安定な動作を事前に行い、計測時の動作を
安定にすることができるので、安定した時間測定がで
き、正確な流速測定を行うことができるという効果があ
る。Further, the ultrasonic anemometer according to claim 7 operates the delay circuit for a predetermined time immediately before the measurement, performs an unstable operation in the early stage of the operation of the delay circuit in advance, and stably operates the delay circuit. Therefore, there is an effect that stable time measurement can be performed and accurate flow velocity measurement can be performed.
【図１】本発明の実施例１における超音波流速計の全体
のブロック図FIG. 1 is an overall block diagram of an ultrasonic anemometer according to a first embodiment of the present invention.
【図２】同流速計における受信信号の受信タイミングを
あらわす図FIG. 2 is a diagram showing a reception timing of a reception signal in the current meter.
【図３】本発明の実施例２における超音波流速計の全体
のブロック図FIG. 3 is an overall block diagram of an ultrasonic anemometer according to a second embodiment of the present invention.
【図４】本発明の実施例３における超音波流速計の全体
のブロック図FIG. 4 is an overall block diagram of an ultrasonic current meter according to a third embodiment of the present invention.
【図５】本発明の実施例４における超音波流速計の全体
のブロック図FIG. 5 is an overall block diagram of an ultrasonic anemometer according to a fourth embodiment of the present invention.
【図６】本発明の実施例５における超音波流速計の全体
のブロック図FIG. 6 is an overall block diagram of an ultrasonic anemometer according to a fifth embodiment of the present invention.
【図７】本発明の実施例６における超音波流速計の全体
のブロック図FIG. 7 is an overall block diagram of an ultrasonic anemometer according to a sixth embodiment of the present invention.
【図８】従来の超音波流速計の全体のブロック図FIG. 8 is an overall block diagram of a conventional ultrasonic current meter.
１２ 超音波センサ １３ 超音波センサ １４ 駆動回路 １５ 制御部 １６ タイミング検知回路 １７ タイマ １８ 演算部 １９ 繰り返し回路 ２０ 位相制御回路 ２１ 可変利得アンプ ２２ レベル検知回路 ２３ 利得制御回路 ２４ 遅延回路 REFERENCE SIGNS LIST 12 ultrasonic sensor 13 ultrasonic sensor 14 drive circuit 15 control unit 16 timing detection circuit 17 timer 18 operation unit 19 repetition circuit 20 phase control circuit 21 variable gain amplifier 22 level detection circuit 23 gain control circuit 24 delay circuit
───────────────────────────────────────────────────── フロントページの続き (72)発明者 足立 明久 大阪府門真市大字門真1006番地 松下電器 産業株式会社内 Ｆターム(参考） 2F035 DA22 DA24 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Akihisa Adachi 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F-term (reference) 2F035 DA22 DA24
Claims (7)
る一対の超音波センサと、一方の前記超音波センサを駆
動する駆動回路と、前記駆動回路を動作させるトリガ信
号と前記駆動回路へ駆動開始位相を１８０°変化させる
位相制御信号とを出力する制御部と、他方の前記超音波
センサの受信信号を前記位相制御信号に応じた変化方向
でかつ所定の電位のとき受信タイミングを決定するタイ
ミング検知回路と、少なくとも前記駆動回路による前記
超音波センサの駆動から前記タイミング検知回路が受信
タイミングを決定するまでの超音波の伝搬時間を測定す
るタイマと、異なる駆動開始位相で測定した複数の前記
タイマの値から前記一対の超音波センサ間の流速を演算
によってもとめる演算部とを備えた超音波流速計。1. A pair of ultrasonic sensors arranged in a fluid to be measured for transmitting and receiving ultrasonic waves, a driving circuit for driving one of the ultrasonic sensors, a trigger signal for operating the driving circuit, and a signal to the driving circuit. A control unit for outputting a phase control signal for changing the driving start phase by 180 °, and determining a reception timing when the reception signal of the other ultrasonic sensor is in a change direction corresponding to the phase control signal and at a predetermined potential. A timing detection circuit, at least a timer that measures the propagation time of the ultrasonic wave from the driving of the ultrasonic sensor by the drive circuit until the timing detection circuit determines the reception timing, and a plurality of the measurement at different drive start phases. An ultrasonic current meter comprising: an arithmetic unit for calculating the flow velocity between the pair of ultrasonic sensors based on a timer value.
る一対の超音波センサと、一方の前記超音波センサを駆
動する駆動回路と、前記駆動回路を動作させるトリガ信
号を出力する制御部と、他方の前記超音波センサの受信
信号を前記位相制御信号に応じた変化方向でかつ所定の
電位のとき受信タイミングを決定するタイミング検知回
路と、前記タイミング検知回路の出力を前記駆動回路の
トリガ信号として前記駆動回路へ出力しかつその回数を
計測し所定の回数で動作を停止する繰り返し回路と、前
記駆動回路へ駆動開始位相を１８０°変化させる位相制
御信号を前記繰り返し回路の計測する繰り返し回数に応
じて変え出力する位相制御回路と、少なくとも前記駆動
回路による前記超音波センサの駆動から前記繰り返し回
路の動作停止までの超音波の伝搬時間を測定するタイマ
と、前記タイマの値から前記一対の超音波センサ間の流
速を演算によってもとめる演算部とを備えた超音波流速
計。2. A pair of ultrasonic sensors arranged in a fluid to be measured for transmitting and receiving ultrasonic waves, a driving circuit for driving one of the ultrasonic sensors, and a control unit for outputting a trigger signal for operating the driving circuit. A timing detection circuit that determines a reception timing when a reception signal of the other ultrasonic sensor is in a change direction according to the phase control signal and has a predetermined potential, and an output of the timing detection circuit is a trigger of the drive circuit. A repetition circuit that outputs a signal to the drive circuit and measures the number of times, and stops the operation at a predetermined number of times; A phase control circuit that changes and outputs according to the above, from at least the driving of the ultrasonic sensor by the drive circuit to the stop of the operation of the repetition circuit A timer for measuring the propagation time of the ultrasonic wave, an ultrasonic flow rate meter and an arithmetic unit which obtains by calculating the flow rate between the pair of ultrasonic sensors from the value of the timer.
る一対の超音波センサと、一方の超音波センサを駆動す
る駆動回路と、他方の超音波センサで受信した受信信号
を設定された増幅率で増幅する可変利得アンプと、前記
可変利得アンプの出力から受信タイミングを判定するタ
イミング検知回路と、前記可変利得アンプの出力に対応
した信号を出力するレベル検知回路と、前記レベル検知
回路の出力を受け前記可変利得アンプの出力をほぼ一定
に制御する利得制御部と、超音波の伝播時間を測定する
タイマと、前記タイマから得たデータをもとに流速を演
算によって求める演算部とを備え、前記演算部によって
求めた流速が所定の流速以上になったときに、前記利得
制御部が前記可変利得アンプの増幅率を所定の増幅率に
固定する超音波流速計。3. A pair of ultrasonic sensors arranged in a fluid to be measured and transmitting and receiving ultrasonic waves, a driving circuit for driving one ultrasonic sensor, and a reception signal received by the other ultrasonic sensor are set. A variable gain amplifier that amplifies at an amplification factor, a timing detection circuit that determines reception timing from an output of the variable gain amplifier, a level detection circuit that outputs a signal corresponding to the output of the variable gain amplifier, and a level detection circuit. A gain control unit that receives the output and controls the output of the variable gain amplifier to be substantially constant, a timer that measures the propagation time of the ultrasonic wave, and a calculation unit that calculates the flow velocity based on the data obtained from the timer. The gain control unit fixes the gain of the variable gain amplifier to a predetermined gain when the flow rate obtained by the arithmetic unit is equal to or higher than a predetermined flow rate. Total.
る一対の超音波センサと、一方の超音波センサを駆動す
る駆動回路と、他方の超音波センサで受信した受信信号
を設定された増幅率で増幅する可変利得アンプと、前記
可変利得アンプの出力から受信タイミングを判定するタ
イミング検知回路と、超音波の伝播時間を測定するタイ
マと、前記タイマから得たデータをもとに流速を演算に
よって求める演算部と、前記演算部によって求めた流速
に応じて前記可変利得回路の増幅率を制御する利得制御
部とを備えた超音波流速計。4. A pair of ultrasonic sensors arranged in a fluid to be measured for transmitting and receiving ultrasonic waves, a driving circuit for driving one ultrasonic sensor, and a reception signal received by the other ultrasonic sensor are set. A variable gain amplifier that amplifies at an amplification factor, a timing detection circuit that determines reception timing from the output of the variable gain amplifier, a timer that measures the propagation time of ultrasonic waves, and a flow rate based on data obtained from the timer. An ultrasonic flowmeter comprising: a calculation unit obtained by calculation; and a gain control unit that controls an amplification factor of the variable gain circuit according to the flow speed obtained by the calculation unit.
る一対の超音波センサと、一方の超音波センサを駆動す
る駆動回路と、他方の超音波センサで受信した受信信号
を設定された増幅率で増幅する可変利得アンプと、前記
可変利得アンプの出力から受信タイミングを判定するタ
イミング検知回路と、超音波の伝播時間を測定するタイ
マと、前記タイマから得たデータをもとに流速を演算に
よって求める演算部と、前記可変利得アンプの出力に対
応した信号を出力するレベル検知回路と、前記レベル検
知回路の出力を受け前記可変利得アンプの出力をほぼ一
定に制御する利得制御部とを備え、前記レベル検知回路
の出力変動が所定の値以上になったときに、前記利得制
御部が前記演算部によって求めた流速に応じて前記可変
利得回路の増幅率を制御する超音波流速計。5. A pair of ultrasonic sensors arranged in a fluid to be measured for transmitting and receiving ultrasonic waves, a driving circuit for driving one ultrasonic sensor, and a reception signal received by the other ultrasonic sensor are set. A variable gain amplifier that amplifies at an amplification factor, a timing detection circuit that determines reception timing from the output of the variable gain amplifier, a timer that measures the propagation time of ultrasonic waves, and a flow rate based on data obtained from the timer. An operation unit obtained by an operation, a level detection circuit that outputs a signal corresponding to the output of the variable gain amplifier, and a gain control unit that receives the output of the level detection circuit and controls the output of the variable gain amplifier to be substantially constant. And when the output fluctuation of the level detection circuit becomes equal to or more than a predetermined value, the gain control unit controls the amplification factor of the variable gain circuit according to the flow rate obtained by the calculation unit. Ultrasonic flow rate meter for controlling.
と最小値より平均値を求め増幅率を制御する請求項５記
載の超音波流量計。6. The ultrasonic flowmeter according to claim 5, wherein the gain control section calculates an average value from the maximum value and the minimum value of the level detection circuit output and controls the amplification factor.
る一対の超音波センサと、一方の前記超音波センサを駆
動する駆動回路と、前記駆動回路を動作させるトリガ信
号を出力する制御部と、他方の前記超音波センサ出力を
受け受信タイミングを決定するタイミング検知回路と、
前記タイミング検知回路の出力を所定の遅延時間遅れて
前記駆動回路のトリガ信号として出力する遅延回路と、
超音波の送受信そして遅延回路で遅延時間の後に再度超
音波の送受信を繰り返すという動作回数を計測し所定の
回数で動作を停止する繰り返し回路と、少なくとも前記
駆動回路による前記超音波センサの駆動から前記繰り返
し回路の動作停止までの超音波の伝搬時間を測定するタ
イマと、前記タイマの値から前記一対の超音波センサ間
の流速を演算によってもとめる演算部とを備え、前記遅
延回路を測定の直前に所定時間動作させる超音波流速
計。7. A pair of ultrasonic sensors arranged in a fluid to be measured for transmitting and receiving ultrasonic waves, a driving circuit for driving one of the ultrasonic sensors, and a control unit for outputting a trigger signal for operating the driving circuit. A timing detection circuit that receives the output of the other ultrasonic sensor and determines a reception timing;
A delay circuit that outputs the output of the timing detection circuit as a trigger signal of the drive circuit with a predetermined delay time delay,
A repetition circuit for measuring the number of operations of repeating transmission and reception of ultrasonic waves after a delay time in the transmission and reception of ultrasonic waves and the delay circuit and stopping the operation at a predetermined number of times, and at least from the driving of the ultrasonic sensor by the driving circuit, A timer for measuring the propagation time of the ultrasonic wave until the operation of the repetitive circuit is stopped, and a calculating unit for calculating the flow velocity between the pair of ultrasonic sensors from the value of the timer by calculation, and the delay circuit immediately before the measurement. An ultrasonic current meter operated for a predetermined time.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28909498A JP4140095B2 (en) | 1998-10-12 | 1998-10-12 | Ultrasonic current meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28909498A JP4140095B2 (en) | 1998-10-12 | 1998-10-12 | Ultrasonic current meter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000121402A true JP2000121402A (en) | 2000-04-28 |
| JP4140095B2 JP4140095B2 (en) | 2008-08-27 |
Family
ID=17738734
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28909498A Expired - Fee Related JP4140095B2 (en) | 1998-10-12 | 1998-10-12 | Ultrasonic current meter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4140095B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002365111A (en) * | 2001-06-11 | 2002-12-18 | Aichi Tokei Denki Co Ltd | Ultrasonic flowmeter |
-
1998
- 1998-10-12 JP JP28909498A patent/JP4140095B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002365111A (en) * | 2001-06-11 | 2002-12-18 | Aichi Tokei Denki Co Ltd | Ultrasonic flowmeter |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4140095B2 (en) | 2008-08-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6915704B2 (en) | Ultrasonic flowmeter including stable flow rate calculation means based on instantaneous flow rate | |
| EP2515089B1 (en) | Flow rate measuring device | |
| JP3624642B2 (en) | Fluid measuring device | |
| WO2014006881A1 (en) | Flow quantity measuring apparatus | |
| EP3438621B1 (en) | Flow rate measurement device and method using the device | |
| JP3427762B2 (en) | Ultrasonic flow meter | |
| JP4140095B2 (en) | Ultrasonic current meter | |
| JP3624743B2 (en) | Ultrasonic flow meter | |
| JP2000329597A5 (en) | ||
| JP5135806B2 (en) | Fluid flow measuring device | |
| JP5135807B2 (en) | Fluid flow measuring device | |
| JP4236479B2 (en) | Ultrasonic transceiver | |
| CN109708729B (en) | Automatic gain adjustment method for metering signal of ultrasonic meter and ultrasonic gas meter | |
| JP3335600B2 (en) | Coriolis mass flowmeter | |
| JP3622613B2 (en) | Ultrasonic flow meter | |
| JP2004069525A (en) | Flow rate measuring apparatus | |
| JPH0117090B2 (en) | ||
| WO2019049658A1 (en) | Flow rate measuring device | |
| JP2001183195A5 (en) | ||
| JPS6050287B2 (en) | Ultrasonic measuring device | |
| JPH02280010A (en) | Vortex flowmeter | |
| JPH09196729A (en) | Correlative flowmeter and vortex flowmeter | |
| JP2000146647A (en) | Ultrasonic flowmeter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20050926 |
|
| RD01 | Notification of change of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7421 Effective date: 20051013 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20080228 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20080304 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20080422 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20080520 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20080602 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110620 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110620 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120620 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130620 Year of fee payment: 5 |
|
| LAPS | Cancellation because of no payment of annual fees |