JP5287628B2 - Fluid flow measuring device - Google Patents

Description

本発明は、物理信号として特に超音波などを利用して気体や液体の流量などを計測するようにした流体の流れ計測装置に関する。   The present invention relates to a fluid flow measuring apparatus that measures the flow rate of gas or liquid using, for example, ultrasonic waves as physical signals.

物理信号として超音波を用いた従来の流体の流れ計測装置を図８を参照して説明すると、流体が流れる流路１０１の上流側と下流側とに一対の超音波振動子１０２，１０３が配置されており、超音波が流体を斜めに横切るようにしてある。   A conventional fluid flow measuring device using ultrasonic waves as physical signals will be described with reference to FIG. 8. A pair of ultrasonic transducers 102 and 103 are arranged on the upstream side and the downstream side of the flow path 101 through which the fluid flows. The ultrasonic waves cross the fluid diagonally.

そして、前記一対の超音波振動子１０２，１０３間を伝搬する超音波の伝搬時間から流体の流速を計測し、これにもとづき流量を演算していた。   Then, the flow velocity of the fluid is measured from the propagation time of the ultrasonic wave propagating between the pair of ultrasonic transducers 102 and 103, and the flow rate is calculated based on this.

例えば、超音波振動子１０２、１０３間で交互に超音波を送受信させて流体の流れに対して順方向と逆方向の超音波の伝搬時間の差を一定間隔を置いて計り、伝搬時間差信号として出力する働きを持つ。この伝搬時間差信号を受けて演算手段（図示せず）により被計測流体の流速及び流量を算出するものである。   For example, ultrasonic waves are alternately transmitted and received between the ultrasonic transducers 102 and 103, and the difference between the propagation times of the ultrasonic waves in the forward direction and the reverse direction with respect to the flow of the fluid is measured at regular intervals, and the propagation time difference signal is obtained. Has a function to output. In response to this propagation time difference signal, the calculation means (not shown) calculates the flow velocity and flow rate of the fluid to be measured.

なお、図中の実線矢印１０４は流体の流れる方向を示し、破線矢印１０５は超音波の伝搬する方向を示している。流体の流れる方向と、超音波の伝搬する方向とは角θで交叉している（例えば、特許文献１参照）。   In addition, the solid line arrow 104 in a figure shows the direction through which a fluid flows, and the broken line arrow 105 has shown the direction through which an ultrasonic wave propagates. The direction in which the fluid flows and the direction in which the ultrasonic waves propagate intersect at an angle θ (for example, see Patent Document 1).

流速の求め方を説明する。図９において、被測定流体の流れる流路１０６と、前記流路１０６に配置された超音波を送受信する第１の振動子１０７、第２の振動子１０８を設置し、前記第１の振動子１０７と前記第２の振動子１０８を駆動する送信手段１０９と、前記第１の振動子１０７と前記第２の振動子１０８の受信信号を受け、信号を増幅する受信手段１１０と、受信手段１１０の信号が予め定めた範囲になると信号を出す受信点検知手段１１１と、前記受信点検知手段１１１の出力を記憶する２つの受信点記憶手段１１２と、前記受信点記憶手段１１２の信号を用いて振動子間を伝搬した超音波信号の伝搬時間を計時する計時手段１１３と、前記計時手段１１３の計時差に基づいて流量を算出する流量演算手段１１４とを有するものである。   Explain how to find the flow velocity. In FIG. 9, a flow path 106 through which a fluid to be measured flows, a first vibrator 107 and a second vibrator 108 that transmit and receive ultrasonic waves arranged in the flow path 106 are installed, and the first vibrator 107, a transmission means 109 for driving the second vibrator 108, a reception means 110 for receiving the signals received by the first vibrator 107 and the second vibrator 108 and amplifying the signals, and a reception means 110 Using the signal of the reception point storage means 112, the reception point storage means 112 for storing the output of the reception point detection means 111, and the reception point storage means 112 for storing the output of the reception point detection means 111 It has time measuring means 113 for measuring the propagation time of the ultrasonic signal propagated between the transducers, and a flow rate calculating means 114 for calculating the flow rate based on the time difference of the time measuring means 113.

さらに、送信手段１０９と第１の振動子１０７、および第２の振動子１０８と受信手段１１０の間に切換手段１１５を設け、第１の振動子１０７と第２の振動子１０８が超音波の送受信を切換えて動作するようにしている。１１６は受信波判定手段、１１７は制御手段である。   Further, a switching means 115 is provided between the transmission means 109 and the first vibrator 107, and between the second vibrator 108 and the reception means 110, and the first vibrator 107 and the second vibrator 108 are ultrasonic waves. It operates by switching between transmission and reception. Reference numeral 116 denotes a received wave determination means, and 117 denotes a control means.

特開２００６−２００８０２号公報JP 2006-200802 A

しかしながら、前記従来の計測装置では、超音波に限らず物理信号を用いて伝搬時間から流量を求めることは可能であるが、器具判別を行う等の特別な動作を必要とする場合は上記のように０．１秒程度の時間分解能を求められている。   However, in the conventional measuring apparatus, it is possible to obtain the flow rate from the propagation time using a physical signal as well as the ultrasonic wave. However, when a special operation such as instrument discrimination is required, as described above. Therefore, a time resolution of about 0.1 second is required.

このような高頻度で計測を行うシステムを構築する場合、計測回数が膨大になるため消
費電力の増大になってしまう。通常数秒に一回の程度の計測に比べて数十倍の計測回数になるからである。 When constructing such a system that performs measurement with high frequency, the number of measurements becomes enormous, resulting in an increase in power consumption. This is because the number of times of measurement is several tens of times that of a measurement that is usually once every few seconds.

また、計時手段で求めた伝搬時間を流量演算手段に通信するのに要する時間も多くなり、通常流量演算手段として用いられているマイクロコンピュータ等はこの通信時間の増大によりその他の処理が規定時間内に終了することが難しくなってくる。   In addition, the time required to communicate the propagation time obtained by the time measuring means to the flow rate calculating means also increases, and the microcomputers or the like normally used as the flow rate calculating means have other processing within the specified time due to this increase in communication time. It will be difficult to finish.

しかしながら、例えば家庭用のガスメータのような場合はガスを利用している時間が一日のうちわずかであり、それ以外の時間は流量がゼロであることを計測していることになる。   However, in the case of a gas meter for home use, for example, the time during which the gas is used is small during the day, and the flow rate is measured at other times.

本発明は、前記従来の課題を解決するもので、高頻度で計測を繰り返す場合でも伝搬時間の情報伝達にかかる処理時間を短くし、高精度な計測を実現しつつ、省電力動作を実現することを目的としている。   The present invention solves the above-described conventional problem, and realizes power saving operation while shortening the processing time required for information transmission of propagation time even when repeating measurement frequently and realizing highly accurate measurement. The purpose is that.

前記従来の課題を解決するために、本発明の流体の流れ計測装置は、被測定流体の流れる流路内に物理信号を出力し、前記流路内を伝播した物理信号を入力する一対の物理信号入出力手段と、前記一方の物理信号入出力手段を駆動する送信手段と、前記他方の物理信号入出力手段で検知した信号を電気信号に変換する受信手段と、前記物理信号入出力手段の送受信の切換手段と、前記受信手段の信号を用いて物理信号出力手段から物理信号入力手段までの物理信号の伝播時間を計時する計時手段と、前記計時手段の値を記憶する記憶手段と、前記記憶手段の値の差が一定値以上かを判断するカウント差検出手段と、前記計時手段の計時差に基づいて流量を算出する流量演算手段と、前記物理信号入出力手段、送信手段、受信手段、切換手段、計時手段、記憶手段、カウント差検出手段、および流量演算手段の少なくとも１つを制御する制御手段とを備え、前記制御手段は前記カウント差検出手段の値に応じて前記記憶手段の値を前記流量演算手段に通信する通信制御手段を有するものである。   In order to solve the above-described conventional problems, a fluid flow measurement device according to the present invention outputs a physical signal into a flow path through which a fluid to be measured flows and inputs a physical signal that has propagated through the flow path. A signal input / output means, a transmission means for driving the one physical signal input / output means, a reception means for converting a signal detected by the other physical signal input / output means into an electrical signal, and a physical signal input / output means Transmission / reception switching means, timing means for measuring the propagation time of the physical signal from the physical signal output means to the physical signal input means using the signal of the receiving means, storage means for storing the value of the timing means, Count difference detection means for determining whether the difference in the values of the storage means is greater than a certain value, flow rate calculation means for calculating a flow rate based on the time difference of the time measurement means, the physical signal input / output means, transmission means, reception means , Switching means, Control means for controlling at least one of a time means, a storage means, a count difference detection means, and a flow rate calculation means, wherein the control means sets the value of the storage means in accordance with the value of the count difference detection means. Communication control means for communicating with the calculation means is provided.

この構成により、高頻度で計測を繰り返す場合でも伝搬時間差が予め定めた時間以上発生した時にだけ伝搬時間情報を流量演算手段に伝送するようにして伝搬時間の情報伝達にかかる処理時間を短くし、高精度な計測を実現しつつ、省電力動作を実現できる。   With this configuration, even when the measurement is repeated frequently, the propagation time information is transmitted to the flow rate calculation means only when the propagation time difference occurs for a predetermined time or more, thereby shortening the processing time required for the propagation time information transmission, Power-saving operation can be achieved while realizing highly accurate measurement.

本発明の流体の流れ計測装置は、伝搬時間差を確認することにより上流側から下流側への超音波の伝搬時間と下流側から上流側への超音波の伝搬時間の差がわかるため、伝搬時間差が予め定めた時間以上発生する場合、特に流れの変化があった時に伝搬時間情報を流量演算手段に伝送するようにして伝搬時間の情報伝達にかかる処理時間を短くすることができる。またそれ以外の条件では伝搬時間を伝送することを控えるため伝送時間の短縮や流量演算の簡素が可能になり、高精度な計測を実現しつつ、省電力動作を実現できる。   In the fluid flow measuring device of the present invention, since the difference in propagation time between the ultrasonic waves from the upstream side to the downstream side and the propagation time of the ultrasonic waves from the downstream side to the upstream side are known by checking the propagation time difference, Occurs for a predetermined time or more, particularly when there is a flow change, the propagation time information can be transmitted to the flow rate calculation means, thereby shortening the processing time required for transmitting the propagation time information. In addition, since transmission time is not transmitted under other conditions, transmission time can be shortened and flow rate calculation can be simplified, and power saving operation can be realized while realizing high-precision measurement.

本発明の実施の形態１を示す流体の流れ計測装置の全体ブロック図FIG. 1 is an overall block diagram of a fluid flow measuring apparatus showing Embodiment 1 of the present invention. 同計測装置の動作を示すタイミング図Timing chart showing the operation of the measurement device 同計測装置における受信波を示すタイミング図Timing chart showing received waves in the same measuring device 同計測装置の流速または流量計測装置他の動作を示す記憶手段周辺のブロック図Block diagram around the storage means showing the flow rate or flow rate measurement device and other operations of the measurement device 同計測装置の他の動作を示す記憶手段周辺のブロック図Block diagram around the storage means showing other operations of the measuring device 同計測装置の動作を示す記憶手段周辺のブロック図Block diagram around the storage means showing the operation of the measurement device 同計測装置の他の例を示す記憶手段周辺のブロック図Block diagram around storage means showing another example of the same measuring apparatus 従来の流量計測装置の断面図Sectional view of a conventional flow measurement device 従来の流量計測装置のブロック図Block diagram of a conventional flow measurement device

第１の発明は、被測定流体の流れる流路内に物理信号を出力し、前記流路内を伝播した物理信号を入力する一対の物理信号入出力手段と、前記一方の物理信号入出力手段を駆動する送信手段と、前記他方の物理信号入出力手段で検知した信号を電気信号に変換する受信手段と、前記物理信号入出力手段の送受信の切換手段と、前記受信手段の信号を用いて物理信号出力手段から物理信号入力手段までの物理信号の伝播時間を計時する計時手段と、前記計時手段の値を記憶する記憶手段と、前記記憶手段の値の差が一定値以上かを判断するカウント差検出手段と、前記計時手段の計時差に基づいて流量を算出する流量演算手段と、前記物理信号入出力手段、送信手段、受信手段、切換手段、計時手段、記憶手段、カウント差検出手段、および流量演算手段の少なくとも１つを制御する制御手段とを備え、前記制御手段は前記カウント差検出手段の値に応じて前記記憶手段の値を前記流量演算手段に通信する通信制御手段を有するものである。   According to a first aspect of the present invention, there is provided a pair of physical signal input / output means for outputting a physical signal into a flow path through which a fluid to be measured flows, and inputting the physical signal propagated through the flow path, and the one physical signal input / output means. A transmission means for driving the signal, a reception means for converting a signal detected by the other physical signal input / output means into an electrical signal, a transmission / reception switching means for the physical signal input / output means, and a signal from the reception means. It is determined whether a timing means for measuring the propagation time of the physical signal from the physical signal output means to the physical signal input means, a storage means for storing the value of the time measuring means, and whether the difference between the values of the storage means is a certain value or more. Count difference detection means, flow rate calculation means for calculating a flow rate based on the time difference of the time measurement means, physical signal input / output means, transmission means, reception means, switching means, time measurement means, storage means, count difference detection means , And flow Control means for controlling at least one of the calculation means, and the control means has communication control means for communicating the value of the storage means to the flow rate calculation means according to the value of the count difference detection means. .

この構成により、高頻度で計測を繰り返す場合でも伝搬時間差が予め定めた時間以上発生した時にだけ伝搬時間情報を流量演算手段に伝送するようにして伝搬時間の情報伝達にかかる処理時間を短くし、高精度な計測を実現しつつ、省電力動作を実現できる。   With this configuration, even when the measurement is repeated frequently, the propagation time information is transmitted to the flow rate calculation means only when the propagation time difference occurs for a predetermined time or more, thereby shortening the processing time required for the propagation time information transmission, Power-saving operation can be achieved while realizing highly accurate measurement.

第２の発明は、特に第１の発明において、計時手段は基準時間を計測する第１のカウンタ、詳細時間を計測する第２のカウンタを有し、記憶手段は前記前記第１のカウンタと前記第２のカウンタの出力を個々に記憶し、カウント差検出手段は前記記憶手段に個々に記憶した前記第１のカウンタと前記第２のカウンタの出力別に設けることにより、伝搬時間の差の発生している箇所をできるだけ小さい範囲で確実に捕らえることを可能にする。   According to a second aspect of the invention, particularly in the first aspect of the invention, the time measuring means includes a first counter for measuring a reference time and a second counter for measuring a detailed time, and the storage means includes the first counter and the first counter. The outputs of the second counter are individually stored, and the count difference detecting means is provided separately for the outputs of the first counter and the second counter individually stored in the storage means, thereby generating a difference in propagation time. This makes it possible to reliably capture the area that is in the smallest possible range.

第３の発明は、特に、第１、または２の発明で、制御手段は、第１のカウンタと第２のカウンタの出力に対して個々に設けたカウント差検出手段の出力により差が発生している信号を記憶手段から流量演算手段に通信する通信制御手段の通信選択手段を設けることにより伝搬時間の差の発生している箇所をできるだけ小さい範囲で確実に捕らえると共に、より短時間で通信することが可能になる。   The third aspect of the invention is particularly the first or second aspect of the invention, wherein the control means generates a difference by the output of the count difference detecting means provided individually with respect to the outputs of the first counter and the second counter. By providing the communication selection means of the communication control means for communicating the received signal from the storage means to the flow rate calculation means, the location where the difference in propagation time is generated can be reliably captured in the smallest possible range and communicated in a shorter time It becomes possible.

第４の発明は、特に、第１の発明で制御手段は、記憶手段の値を流量演算手段に通信する際に２回目以降は最初の記憶手段の値との差分のみを通信する差分通信手段を設けることにより流量演算手段への通信量を減らすことにより、より短時間で通信することが可能になる。   In the fourth invention, in particular, in the first invention, the control means communicates only the difference from the value of the first storage means after the second time when the value of the storage means is communicated to the flow rate calculation means. By reducing the amount of communication to the flow rate calculation means, it becomes possible to communicate in a shorter time.

第５の発明は、特に、第１の発明で制御手段は、記憶手段の値を流量演算手段に通信する際に用いる差分通信手段は正の差分となるように記憶手段の通信する順序を入れ替えることが可能な構成とすることにより伝搬時間情報を受け取った流量演算手段の演算が減算処理を無くすことができより短時間での処理が可能になる。   In the fifth invention, in particular, in the first invention, the control means changes the order of communication of the storage means so that the difference communication means used when communicating the value of the storage means to the flow rate calculation means becomes a positive difference. By adopting such a configuration, the calculation of the flow rate calculation means that has received the propagation time information can eliminate the subtraction process, and the process can be performed in a shorter time.

第６の発明は、特に、第１の発明でカウント差検出手段は閾値設定手段を有し、前記閾値設定手段の値は変更可能とすることにより伝搬時間の差として発生する時間を調節することが可能になり、より高精度の時間計測やより省電力の処理に対応する閾値を容易に設定することが可能になる。   In a sixth aspect of the present invention, in particular, in the first aspect, the count difference detecting means has a threshold setting means, and the value of the threshold setting means can be changed to adjust the time generated as the difference in propagation time. Therefore, it is possible to easily set a threshold value corresponding to more accurate time measurement and more power saving processing.

第７の発明は、特に、第１の発明で制御手段はカウント差検出手段の値が一定回数以上変化しない場合は計時手段の値を確認する異常確認手段を有する構成とすることにより伝搬時間差が長時間発生しない場合は計時手段の値に異常が発生していないかを確認するこ
とができ、早期に異常を検知することが可能になる。 In the seventh invention, in particular, in the first invention, the control means has an abnormality confirmation means for confirming the value of the time measuring means when the value of the count difference detecting means does not change more than a certain number of times, so that the propagation time difference is reduced. When it does not occur for a long time, it can be confirmed whether or not an abnormality has occurred in the value of the time measuring means, and it becomes possible to detect the abnormality early.

以下本発明の実施の形態を図面を参照しつつ説明する。なお、実施の形態が本発明を限定するものではない。   Embodiments of the present invention will be described below with reference to the drawings. The embodiments do not limit the present invention.

（実施の形態１）
図１おいて、流体の流れる流路１と、前記流路１に配置された超音波を送受信する第１の振動子２、第２の振動子３と、前記第１の振動子２と前記第２の振動子３を駆動する送信手段４と、前記第１の振動子２と前記第２の振動子３の受信信号を受け信号を増幅する受信手段５と、この受信手段５で受信した受信波を判定する受信波判定手段６と、受信手段５の信号が予め定めた範囲になると信号を出す受信点検知手段７と、前記受信点検知手段７の信号を用いて振動子間を伝搬した超音波信号の伝搬時間を計時する計時手段８と、前記計時手段８の値を記憶する記憶手段９と、前記記憶手段９の値の差が一定値以上かを判断するカウント差検出手段１０と、前記計時手段８の計時差に基づいて流量を算出する流量演算手段１１とを有し、制御手段１２は切替手段１３を介して送受信の方向を変え、伝搬時間の差を測定するものである。 (Embodiment 1)
In FIG. 1, a flow path 1 through which a fluid flows, a first vibrator 2, a second vibrator 3 that transmits and receives an ultrasonic wave disposed in the flow path 1, the first vibrator 2, and the Transmitting means 4 for driving the second vibrator 3, receiving means 5 for receiving signals received by the first vibrator 2 and the second vibrator 3 and amplifying the signals, and receiving means 5 for receiving the signals The received wave determining means 6 for determining the received wave, the receiving point detecting means 7 for outputting a signal when the signal of the receiving means 5 falls within a predetermined range, and the signal of the receiving point detecting means 7 are used to propagate between the transducers. The time measuring means 8 for measuring the propagation time of the ultrasonic signal, the storage means 9 for storing the value of the time measuring means 8, and the count difference detecting means 10 for determining whether the difference between the values of the storage means 9 is equal to or greater than a certain value. And a flow rate calculation means 11 for calculating a flow rate based on the time difference of the time measuring means 8, It means 12 are those change direction of the transmitted and received via the switching means 13, to measure the difference in propagation time.

また、制御手段１２は、前記第１の振動子２、第２の振動子３、切換手段１３、計時手段８、記憶手段１４、カウント差検出手段１０、流量演算手段１１の少なくとも１つを制御するとともに、前記カウント差検出手段１０の値に応じて前記記憶手段１４の値を前記流量演算手段１１に通信する通信制御手段１５を有するものである。   The control means 12 controls at least one of the first vibrator 2, the second vibrator 3, the switching means 13, the timing means 8, the storage means 14, the count difference detection means 10, and the flow rate calculation means 11. In addition, communication control means 15 is provided for communicating the value of the storage means 14 to the flow rate calculation means 11 in accordance with the value of the count difference detection means 10.

図２は送信から受信までのタイミングを、図３は受信波形を拡大したタイミングを示すものである。   FIG. 2 shows the timing from transmission to reception, and FIG. 3 shows the timing when the reception waveform is enlarged.

動作を説明する。制御手段４２による時刻ｔ０における開始信号から計測を開始するとともに送信手段４を介して第１の超音波振動子２を駆動する。そこで発生した超音波信号は流路内を伝搬し時刻ｔ１で第１の超音波振動子２から出た超音波は第２の超音波振動子３に到達する。   The operation will be described. Measurement is started from a start signal at time t 0 by the control means 42 and the first ultrasonic transducer 2 is driven via the transmission means 4. The ultrasonic signal generated there propagates through the flow path, and the ultrasonic wave emitted from the first ultrasonic transducer 2 reaches the second ultrasonic transducer 3 at time t1.

その受信信号は受信手段５で増幅されその信号レベルが予め定めた値（Ｖｒｅｆ）になると受信波判定手段６が受信波が到達したことを判定して信号を出す。この信号を基に受信点検知手段７が動作を開始し、Ｖｒｅｆ後の最初の零クロス点を受信点として信号を出し、この点までの時間を計時手段８で求める。   The received signal is amplified by the receiving means 5 and when the signal level reaches a predetermined value (Vref), the received wave determining means 6 determines that the received wave has arrived and outputs a signal. Based on this signal, the reception point detection means 7 starts to operate, outputs a signal with the first zero cross point after Vref as the reception point, and the time means 8 obtains the time to this point.

ここで第１の超音波振動子２から第２の超音波振動子３までの伝搬時間を記憶手段９−１に記憶し、切換手段１３で送受信を切換えて第２の超音波振動子３から第１の超音波振動子２までの伝搬時間を同様の動作で計時手段８で求め、記憶手段９−２に記憶する。   Here, the propagation time from the first ultrasonic transducer 2 to the second ultrasonic transducer 3 is stored in the storage unit 9-1, and transmission / reception is switched by the switching unit 13, and the second ultrasonic transducer 3 is switched. The propagation time to the first ultrasonic transducer 2 is obtained by the time measuring means 8 by the same operation and stored in the storage means 9-2.

通常の流速または流量計測の動作を説明する。制御手段１２からスタート信号を受けた送信手段４が第１の振動子２を一定時間パルス駆動行うと同時に計時手段８は時間計測始める。   A normal flow rate or flow rate measurement operation will be described. Upon receipt of the start signal from the control means 12, the transmission means 4 performs pulse driving of the first vibrator 2 for a certain time, and at the same time, the time measuring means 8 starts measuring time.

パルス駆動された第１の振動子２からは超音波が送信される。第１の振動子２から送信した超音波は被測定流体中を伝搬し、第２の振動子３で受信される。   Ultrasound is transmitted from the pulse-driven first vibrator 2. The ultrasonic wave transmitted from the first vibrator 2 propagates through the fluid to be measured and is received by the second vibrator 3.

第２の振動子３の受信出力は、受信手段５で信号を増幅された後、予め定められている受信タイミングの信号レベルで超音波の受信を決定する。   The reception output of the second vibrator 3 amplifies the signal by the receiving means 5 and then determines the reception of the ultrasonic wave at the signal level at a predetermined reception timing.

ここで、計時手段８から得た測定時間をｔ、超音波振動子間の流れ方向の有効距離をＬ
、確度をφ、音速をｃ、被測定流体の流速をｖとすると
ｖ＝（１／ｃｏｓφ）＊（Ｌ／ｔ）−ｃ （式１）
となり、受信手段５は通常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ることが多い。 Here, the measurement time obtained from the time measuring means 8 is t, and the effective distance in the flow direction between the ultrasonic transducers is L.
Where accuracy is φ, sound velocity is c, and flow velocity of the fluid to be measured is v, v = (1 / cos φ) * (L / t) −c (Equation 1)
Therefore, the receiving means 5 is usually configured to compare the reference voltage and the received signal by a comparator.

また、第１の超音波振動子２と第２の超音波振動子３との送信、受信方向を切り替え、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２、３，４）より速度ｖを求めることができる。   Further, the transmission and reception directions of the first ultrasonic transducer 2 and the second ultrasonic transducer 3 are switched, and the respective propagation times of the measured fluid from upstream to downstream and from downstream to upstream are measured ( The speed v can be obtained from Equations 2, 3, and 4).

なお、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。   Note that the measurement time from upstream to downstream is t1, and the measurement time from downstream to upstream is t2.

ｔ１＝Ｌ／（ｃ＋ｖ＊ｃｏｓφ） （式２）
ｔ２＝Ｌ／（ｃ−ｖ＊ｃｏｓφ） （式３）
ｖ＝（Ｌ／２＊ｃｏｓφ）＊［（１／ｔ１）−（１／ｔ２）］ （式４）
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。流速ｖが求まると、それに流路３１の断面積を乗ずることにより流量を導くことができる。 t1 = L / (c + v * cosφ) (Formula 2)
t2 = L / (c−v * cos φ) (Formula 3)
v = (L / 2 * cos φ) * [(1 / t1) − (1 / t2)] (Formula 4)
According to this method, the flow rate can be measured without being affected by the change in the sound speed, and thus it is widely used for measuring the flow velocity, flow rate, distance, and the like. When the flow velocity v is obtained, the flow rate can be derived by multiplying it by the cross-sectional area of the flow path 31.

このような方法で求めた流量により流路の下流側にある器具を判別するためには流量変化量を時系列で把握しておく必要がある。そのために計測の時間間隔は超音波の送受信が可能な範囲で設定できるが、器具判別を行うためには０．１秒の分解能があれば充分である。   In order to discriminate an appliance on the downstream side of the flow path based on the flow rate obtained by such a method, it is necessary to grasp the flow rate change amount in time series. Therefore, the measurement time interval can be set within a range in which ultrasonic waves can be transmitted and received, but a resolution of 0.1 seconds is sufficient for instrument discrimination.

しかし、通常の構成において送信手段４から記憶手段９までは計測誤差を少なくするために１つの回路、具体的には一つの半導体チップ内に収め、演算は別のチップであるマイクロコンピュータなどで行うことが多い。   However, in a normal configuration, the transmission means 4 to the storage means 9 are housed in one circuit, specifically in one semiconductor chip, in order to reduce measurement errors, and the calculation is performed by a microcomputer as another chip. There are many cases.

このため、記憶手段９から流量演算手段１１まではある一定の通信規則に沿ってデータをやり取りする。   For this reason, data is exchanged from the storage means 9 to the flow rate calculation means 11 according to a certain communication rule.

背景技術で示述べたように流量を求めるだけで無く、器具判別を行う等の特別な動作を必要とする場合は０．１秒程度の時間分解能を求められている。このような高頻度で計測を行うシステムを構築する場合、計測回数が膨大になるため消費電力の増大になってしまう。   As shown in the background art, not only the flow rate is obtained, but also a time resolution of about 0.1 seconds is required when a special operation such as device discrimination is required. When constructing such a system that performs measurement with high frequency, the number of measurements becomes enormous, resulting in an increase in power consumption.

通常数秒に一回の程度の計測に比べて数十倍の計測回数になるからである。そして通常流量演算手段として用いられているマイクロコンピュータ等はこの通信時間の増大によりその他の処理が規定時間内に終了することが難しくなってくる。   This is because the number of times of measurement is several tens of times that of a measurement that is usually once every few seconds. In addition, it becomes difficult for a microcomputer or the like normally used as a flow rate calculation means to finish other processing within a specified time due to the increase in communication time.

このような状態でも計測が継続できるようにする方法を説明する。例えば０．１秒単位などの高速でサンプリングする場合、計時手段８の出力から記憶手段９に送られた伝搬時間の情報はよほど大きな流量変化が無い場合、差が見られることは無い。   A method for allowing measurement to continue even in such a state will be described. For example, when sampling is performed at a high speed such as 0.1 second unit, there is no difference when the propagation time information sent from the output of the time measuring means 8 to the storage means 9 has no very large flow rate change.

給湯器などの大量にガスを消費する機器が運転している場合でも１時間あたり数千リットル程度であるから１秒に換算すると１リットル程度、０．１秒ではその十分の一程度の流量変化である。   Even when a device that consumes a large amount of gas, such as a water heater, is operating, it is about several thousand liters per hour. It is.

このため、閾値設定手段１６で設定されたカウント差検出手段１０の閾値として伝搬時間の差を一時間あたりに換算して１リットル程度、時間差として流路断面積にも影響する
が０．０１マイクロ秒として説明する。 For this reason, the difference in propagation time is converted to about 1 liter per hour as the threshold value of the count difference detecting means 10 set by the threshold setting means 16, and the flow area is affected by the time difference of 0.01 micron. It will be described as seconds.

第１の超音波振動子２から第２の超音波振動子３までの伝搬時間を記憶手段９−１に記憶し、切換手段１３で送受信を切換えて第２の超音波振動子３から第１の超音波振動子２までの伝搬時間を同様の動作で計時手段８で求め、記憶手段９−２に記憶する。カウント差検出手段１０にて記憶手段９−１と９−２の差を調べ、時間差が閾値である０．０１マイクロ秒より大きい場合は流量変化があったとして信号を制御手段４２に送出する。   The propagation time from the first ultrasonic transducer 2 to the second ultrasonic transducer 3 is stored in the storage unit 9-1, and transmission / reception is switched by the switching unit 13 to switch the first ultrasonic transducer 3 to the first ultrasonic transducer 3. The propagation time to the ultrasonic transducer 2 is obtained by the time measuring means 8 by the same operation and stored in the storage means 9-2. The count difference detection means 10 checks the difference between the storage means 9-1 and 9-2, and if the time difference is larger than the threshold value of 0.01 microseconds, it sends a signal to the control means 42 that the flow rate has changed.

制御手段１２はカウント差検出手段１０からの信号を受けると通信制御手段１５から指示を出し、記憶手段９−１、９−２の値を流量演算手段４０に送信するように通信制御を行う。   When the control means 12 receives the signal from the count difference detection means 10, it issues an instruction from the communication control means 15, and performs communication control so that the values of the storage means 9-1 and 9-2 are transmitted to the flow rate calculation means 40.

また、伝搬時間差が閾値である０．０１マイクロ秒より小さい場合は流量変化が無かったとして信号を制御手段１２に送出する。制御手段１２はカウント差検出手段１０からの信号を受けると通信制御手段１５から通信制御を行わず、記憶手段９−１、９−２の値を流量演算手段１１には送信しない。   When the propagation time difference is smaller than the threshold value of 0.01 microseconds, a signal is sent to the control means 12 because there is no change in the flow rate. When the control unit 12 receives a signal from the count difference detection unit 10, the control unit 12 does not perform communication control from the communication control unit 15 and does not transmit the values of the storage units 9-1 and 9-2 to the flow rate calculation unit 11.

このように高頻度で計測を繰り返す場合でも伝搬時間差が予め定めた時間以上発生した時にだけ伝搬時間情報を流量演算手段に伝送するようにして伝搬時間の情報伝達にかかる処理時間を短くし、高精度な計測を実現しつつ、省電力動作を実現できる。   Even when the measurement is repeated at a high frequency in this way, the processing time required for transmitting the propagation time information is shortened by transmitting the propagation time information to the flow rate calculation means only when the propagation time difference occurs for a predetermined time or more. Power saving operation can be realized while realizing accurate measurement.

また、計時手段８は基準時間を計測する第１のカウンタ、詳細時間を計測する第２のカウンタを有し、記憶手段は前記前記第１のカウンタと前記第２のカウンタの出力を個々に記憶し、カウント差検出手段１０は前記記憶手段に個々に記憶した前記第１のカウンタと前記第２のカウンタの出力別に設けることにより、流量変化を捉えることがさらに容易になる。   The time measuring means 8 has a first counter for measuring a reference time and a second counter for measuring a detailed time, and the storage means individually stores the outputs of the first counter and the second counter. In addition, by providing the count difference detecting means 10 for each output of the first counter and the second counter individually stored in the storage means, it becomes easier to capture the flow rate change.

例えば、図４に示すように、計時手段８は基準時間を計測する第１のカウンタ１７、詳細時間を計測する第２のカウンタ１８を有する。   For example, as shown in FIG. 4, the time measuring means 8 includes a first counter 17 that measures a reference time and a second counter 18 that measures a detailed time.

第１のカウンタ１７は図２，図３に示すように伝搬時間の大きな時間間隔のカウントを行う。   As shown in FIGS. 2 and 3, the first counter 17 counts time intervals having a long propagation time.

第２のカウンタ１８は図３に示すように受信波がゼロ点を通過した点から次の第１のカウンタ１７の計数するクロックの立ち上がりまでの時間を高速クロックでカウントする。例えば第１のカウンタに用いるクロックが１０ＭＨｚ（時間分解能０・１マイクロ秒）に対してその百倍以上、例えば１ＧＨｚ（時間分解能１ナノ秒）を用いるとする。   As shown in FIG. 3, the second counter 18 counts the time from the point when the received wave passes through the zero point to the rising edge of the clock counted by the first counter 17 with the high-speed clock. For example, it is assumed that the clock used for the first counter is 100 times or more, for example, 1 GHz (time resolution 1 nanosecond) with respect to 10 MHz (time resolution 0.1 microsecond).

そして、第１の超音波振動子２から第２の超音波振動子３までの伝搬時間を第１のカウンタで測定した値を記憶手段９−１Ａに記憶し、第２のカウンタで測定した値を記憶手段９−１Ｂに記憶する。   Then, a value obtained by measuring the propagation time from the first ultrasonic transducer 2 to the second ultrasonic transducer 3 by the first counter is stored in the storage unit 9-1A, and a value measured by the second counter. Is stored in the storage means 9-1B.

切換手段１３で送受信を切換えて第２の超音波振動子３から第１の超音波振動子２までの伝搬時間を同様の動作で計時手段８で求め、第１のカウンタで測定した値を記憶手段９−２Ａに記憶し、第２のカウンタで測定した値を記憶手段９−２Ｂに記憶する。   The transmission / reception is switched by the switching means 13, the propagation time from the second ultrasonic transducer 3 to the first ultrasonic transducer 2 is obtained by the time measuring means 8 by the same operation, and the value measured by the first counter is stored. The value stored in the means 9-2A and measured by the second counter is stored in the storage means 9-2B.

カウント差検出手段１９も第１のカウンタの差を調べるカウント差検出部１９−Ａと、第２のカウンタの差を調べるカウント差検出部１９−Ｂを設けておく。   The count difference detecting means 19 is also provided with a count difference detecting unit 19-A for checking the difference of the first counter and a count difference detecting unit 19-B for checking the difference of the second counter.

そして、カウント差検出手段はカウント差検出部９−Ａで記憶手段９−１Ａと９−２Ａ
の差を調べると共に、カウント差検出部１９−Ｂで記憶手段９−１Ｂと９−２Ｂの差を調べる。 The count difference detecting means is a count difference detecting section 9-A, and storage means 9-1A and 9-2A.
And the difference between the storage means 9-1B and 9-2B is examined by the count difference detector 19-B.

通常はカウント差検出部１９−Ａで大まかな時間差があれば通信制御手段１５から指示を出し、記憶手段９−１，９−２の値を流量演算手段４０に送信するように通信制御を行うが、より詳細に流量変化を調べたいような場合はカウント差検出部１９−Ｂの時間差が予め定めた時間差より大きいと同様に記憶手段９の値を流量演算手段１１に送信するように通信制御を行う。   Usually, if there is a rough time difference in the count difference detection unit 19-A, an instruction is issued from the communication control means 15, and communication control is performed so that the values of the storage means 9-1 and 9-2 are transmitted to the flow rate calculation means 40. However, when it is desired to examine the flow rate change in more detail, the communication control is performed so that the value of the storage unit 9 is transmitted to the flow rate calculation unit 11 in the same manner as when the time difference of the count difference detection unit 19-B is larger than the predetermined time difference. Do.

このように、第２のカウンタ１８を用いることにより伝搬時間の差の発生している箇所をできるだけ小さい範囲で確実に捕らえることが可能になる。   As described above, by using the second counter 18, it is possible to reliably capture a portion where a difference in propagation time is generated in the smallest possible range.

また、図５のように、制御手段１２は、第１のカウンタと第２のカウンタの出力に対して個々に設けたカウント差検出手段１０の出力により差が発生している信号を記憶手段５０から流量演算手段１１に通信する通信制御手段１５の通信選択手段２０を設けることにより通信量を削減することが可能になる。   Further, as shown in FIG. 5, the control unit 12 stores a signal in which a difference is generated by the output of the count difference detection unit 10 provided for each of the outputs of the first counter and the second counter. By providing the communication selection means 20 of the communication control means 15 that communicates with the flow rate calculation means 11, it is possible to reduce the amount of communication.

例えば、伝搬時間を第１のカウンタと第２のカウンタで測定した場合、受信点がカウンタのカウントアップする近傍で無い限り、よほど大流量が流れている場合以外は第１のカウンタで測定した値は切換手段１３の動作前後で変化は無い。そして第２のカウンタで測定した値のみが時間差となっていることが多い。   For example, when the propagation time is measured by the first counter and the second counter, the value measured by the first counter except when the flow rate is very high unless the reception point is in the vicinity of the counter counting up. There is no change before and after the operation of the switching means 13. In many cases, only the value measured by the second counter is a time difference.

このため、カウント差検出手段１０に設けているカウント差検出部１０−Ａとカウント差検出部１０−Ｂのそれぞれの閾値より大きいかを制御手段１２に送出する。   For this reason, whether the count difference detection unit 10-A and the count difference detection unit 10-B provided in the count difference detection unit 10 are larger than the respective thresholds is sent to the control unit 12.

そして、制御手段１２では通信選択手段２０により送られてきた信号により例えば第１のカウンタの差が無い場合でかつ第２のカウンタの差が一定値以上あるような場合は第２のカウンタ値のみを記憶手段９−１Ｂ，９−２Ｂから流量演算手段１１に通信し、第１のカウンタ値は記憶手段９−１Ａのみを通信するように通信するデータを選択する。   Then, in the control means 12, for example, when there is no difference in the first counter due to the signal sent from the communication selection means 20 and the difference in the second counter is more than a certain value, only the second counter value is obtained. Is transmitted from the storage means 9-1B and 9-2B to the flow rate calculation means 11, and the first counter value selects data to be communicated so that only the storage means 9-1A is communicated.

このように、通信選択手段を用いることにより伝搬時間の差の発生している箇所をできるだけ小さい範囲で確実に捕らえると共に、差が発生している情報のみを詳しく通信し、差が無い情報は片側のみを通信するなどしてより短時間で通信することが可能になる。   In this way, by using the communication selection means, the part where the difference in propagation time is generated can be reliably captured in the smallest possible range, and only the information where the difference is generated is communicated in detail. It becomes possible to communicate in a shorter time by communicating only.

また、制御手段１２は、図６のように、記憶手段９の値を流量演算手段１１に通信する際に２回目以降は最初の記憶手段９の値との差分のみを通信する差分通信手段２１を設けることにより流量演算手段への通信量を減らすことにより、より短時間で通信することが可能になる。   Further, as shown in FIG. 6, the control unit 12 communicates only the difference from the value of the first storage unit 9 after the second time when communicating the value of the storage unit 9 to the flow rate calculation unit 11. By reducing the amount of communication to the flow rate calculation means, it becomes possible to communicate in a shorter time.

図６を用いて説明する。今までの説明と同様に伝搬時間を計時手段で求め、記憶手段９に記憶している。カウント差検出手段１１で差があるとの信号を制御手段１２に送った場合、制御手段は最初の伝搬時間情報である記憶手段９−１Ａ，９−１Ｂの値と切換手段１３を動作して伝搬時間を測定した値の記憶手段９−２Ａ，９−２Ｂの値において９−１Ａ、９−１Ｂの値はそのまま送信する。   This will be described with reference to FIG. Similarly to the description so far, the propagation time is obtained by the time measuring means and stored in the storage means 9. When the count difference detection means 11 sends a signal indicating that there is a difference to the control means 12, the control means operates the values of the storage means 9-1A and 9-1B as the first propagation time information and the switching means 13. The values of 9-1A and 9-1B are transmitted as they are in the values of the storage means 9-2A and 9-2B for the values obtained by measuring the propagation time.

しかし、９−２Ａと９−２Ｂの値は最初の９−１Ａおよび９−１Ｂとさほど変わらないため、全部のデータを通信すると動作時間が長くなり消費電力はマイクロコンピュータの負荷が多くなる。   However, since the values of 9-2A and 9-2B are not so different from those of the first 9-1A and 9-1B, if all the data are communicated, the operation time becomes longer and the power consumption increases the load on the microcomputer.

そのため、制御手段１２は差分通信手段１５を用い、記憶手段９−２Ａと９−１Ａの差
、および記憶手段９−２Ｂと９−１Ｂの差を求め通信制御手段１５を用いて流量演算手段１１にその差分情報を送る。 Therefore, the control means 12 uses the difference communication means 15 to obtain the difference between the storage means 9-2A and 9-1A and the difference between the storage means 9-2B and 9-1B, and uses the communication control means 15 to calculate the flow rate calculation means 11. The difference information is sent to.

流量演算手段１１は予め差分が送られてくることがわかっている場合に内部で差分を付加することで正しい伝搬時間情報を組み立てることが可能である。   The flow rate calculation means 11 can assemble correct propagation time information by adding the difference internally when it is known that the difference is sent in advance.

通常制御手段５２は送信手段４からカウント差検出手段１９までと同じ回路内部に作られていることが多いため差分通信手段２１で演算が可能になる。   Since the normal control means 52 is often made in the same circuit as the transmission means 4 to the count difference detection means 19, the differential communication means 21 can perform the calculation.

このように、差分通信手段２１を用い、最初の記憶手段の値との差分のみを通信することにより流量演算手段４０への通信量を減らすことにより、より短時間で通信することが可能になる。   In this way, by using the difference communication means 21 and communicating only the difference from the value of the first storage means, it is possible to communicate in a shorter time by reducing the amount of communication to the flow rate calculation means 40. .

また、伝搬時間の差分を流量演算手段１１に送信する際に、制御手段１２の差分通信手段２１は差分を正となるような演算をする。   Further, when transmitting the difference in propagation time to the flow rate calculation means 11, the difference communication means 21 of the control means 12 performs a calculation so that the difference becomes positive.

例えば、流量が発生している場合は伝搬時間として下流側から上流に向けての方が流れに逆らっているため時間がかかる。   For example, when a flow rate is generated, the propagation time from the downstream side to the upstream side takes time because it is against the flow.

図１の流れの方向より第２の振動子３が下流側になるため、第１の振動子２から送信した場合の伝搬時間情報である記憶手段９−１より第２の振動子３から送信した伝搬時間情報である記憶手段９−２の値の方が通常大きい。   Since the second vibrator 3 is located downstream from the flow direction in FIG. 1, the second vibrator 3 is transmitted from the storage means 9-1 which is propagation time information when transmitted from the first vibrator 2. The value of the storage means 9-2 that is the propagation time information is usually larger.

このため、差分通信手段２１は通常９−２から９−１の差分を求め、流量演算手段１１にその情報を送る。流量演算手段１１ではこの差分と記憶手段９−１からの情報により記憶手段９−２に相当する値を加算により求めることができる。   For this reason, the difference communication means 21 normally obtains a difference from 9-2 to 9-1 and sends the information to the flow rate calculation means 11. The flow rate calculation means 11 can obtain a value corresponding to the storage means 9-2 by adding the difference and the information from the storage means 9-1.

通常演算としては減算より加算の方がアルゴリズムが簡単なため演算処理を短くすることができる。   As a normal calculation, an addition is simpler than an addition, and the calculation process can be shortened.

この説明は流れは常に一定方向を想定しているが、逆流のような場合は伝搬時間の大小は逆転する。そのような場合は差分通信手段２１はフラグなどを用いて差分方向が反対であることを流量演算手段１１に伝えることも可能である。   In this explanation, the flow always assumes a constant direction, but in the case of a reverse flow, the magnitude of the propagation time is reversed. In such a case, the difference communication means 21 can inform the flow rate calculation means 11 that the difference direction is opposite using a flag or the like.

また、カウント差検出手段１０は閾値設定手段１６を有し、前記閾値設定手段１６の値は変更可能とする。   Further, the count difference detecting means 10 has a threshold setting means 16, and the value of the threshold setting means 16 can be changed.

例えば、器具を判別するために高速繰返し計測を行う場合に器具として大型のものしか設置されていないような時は、閾値設定手段１６を介してカウント差検出手段１０のカウント差としての閾値を大きくしておくことが可能である。   For example, when only a large instrument is installed when performing high-speed repeated measurement to discriminate the instrument, the threshold as the count difference of the count difference detection means 10 is increased via the threshold setting means 16. It is possible to keep it.

また、ノイズの多いような環境ではカウント差の閾値を小さくしておくとノイズの影響で本来通信しなくてもよいような計測情報を頻繁に流量演算手段１１に送り、無駄が発生することもある。この場合も閾値を大きくしてノイズ成分による誤判定を少なくすることが可能である。   Also, in a noisy environment, if the count difference threshold is made small, measurement information that does not need to be communicated due to the noise is frequently sent to the flow rate calculation means 11 and waste occurs. is there. In this case as well, the threshold value can be increased to reduce erroneous determination due to noise components.

また、反対に小型器具を使用している環境では、第２のカウンタで測定する値の微小時間差を閾値として設定してよりきめ細かに流量情報を集め、器具の判定を可能にすることも可能になる。
このように、流量演算の目的や器具の種類により伝搬時間の差として発生する時間を調節
することが可能になり、より高精度の時間計測やより省電力の処理に対応する閾値を容易に設定することが可能になる。 On the other hand, in an environment where a small instrument is used, it is also possible to set the minute time difference between the values measured by the second counter as a threshold value and collect the flow rate information more finely, thereby enabling the judgment of the instrument. Become.
In this way, it is possible to adjust the time that occurs as a difference in propagation time depending on the purpose of flow rate calculation and the type of equipment, and it is easy to set a threshold value corresponding to more accurate time measurement and more power-saving processing It becomes possible to do.

また、制御手段１２はカウント差検出手段１９の値が一定回数以上変化しない場合は計時手段８の値を確認する異常確認手段５８を有する構成とする。   Further, the control means 12 has an abnormality confirmation means 58 for confirming the value of the time measuring means 8 when the value of the count difference detection means 19 does not change more than a certain number of times.

図７を用いて説明する。   This will be described with reference to FIG.

今までの説明でカウント差検出手段１０の信号により伝搬時間に予め定めた値以上の時間差が発生した場合は流量変化があるとして伝搬時間情報を記憶手段９から流量演算手段１１に通信するようになっている。   In the description so far, when a time difference greater than a predetermined value is generated in the propagation time by the signal of the count difference detecting means 10, the propagation time information is communicated from the storage means 9 to the flow rate calculating means 11 assuming that there is a flow rate change. It has become.

ここで、ノイズなどの影響で記憶手段９の内容が正しく書き込まれていなかったり、またカウント差演算手段１０の演算処理が正常動作を行っていないようなことも長い動作環境では考えられる。   Here, it is conceivable that the contents of the storage means 9 are not correctly written due to the influence of noise or the like, or that the arithmetic processing of the count difference calculating means 10 is not performing a normal operation in a long operating environment.

このような異常状態を回避する方法として、制御手段１２にはカウント差検出手段１０からの情報が伝えられるが、例えば一定回数（一定時間）以上カウント差が無いというような場合は本当に流量が発生していないのであれば問題ないが、異常状態である可能性も考えられる。   As a method for avoiding such an abnormal state, information from the count difference detection means 10 is transmitted to the control means 12, but for example, when there is no count difference for a certain number of times (a certain time), a flow rate is really generated. If it is not, there is no problem, but there is a possibility of an abnormal state.

このため、予め定めた回数以上カウント差が発生しない状態が続くと制御手段１２内部に設けた異常確認手段が計時手段の値を直接確認し、記憶手段９と比較したり、カウント差検出手段１０の値と比較して正しく動作しているかを確認する。   For this reason, when a state in which the count difference does not occur for a predetermined number of times or more continues, the abnormality confirmation unit provided in the control unit 12 directly confirms the value of the timing unit and compares it with the storage unit 9 or the count difference detection unit 10. Compare with the value of to check if it is working properly.

もし、記憶手段９の値と一致しないような場合は一旦回路をリセットするとか、記憶手段の使用するエリアを変更するなどの処置を行う。   If the value does not match the value stored in the storage means 9, the circuit is reset once or the area used by the storage means is changed.

このように、異常確認手段２２を用いることにより伝搬時間差が長時間発生しない場合は計時手段８の値に異常が発生していないかを確認することができ、早期に異常を検知することが可能になる。   As described above, when the propagation time difference does not occur for a long time by using the abnormality confirmation unit 22, it is possible to confirm whether or not an abnormality has occurred in the value of the timing unit 8, and it is possible to detect the abnormality early. become.

（実施の形態２）
実施の形態１と異なるところは、前記第１の振動子２と前記第２の振動子３と前記切換手段１３と前記計時手段８と前記記憶手段９と前記カウント差検出手段１０と前記流量演算手段１１との少なくとも１つを制御するとともに、前記カウント差検出手段１０の値に応じて前記記憶手段９の値を前記流量演算手段１１に通信する通信制御手段１５を有する制御手段１２の動作を確実にするためのコンピュータを機能させるためのプログラムを有する記憶媒体１４を用いていることである。 (Embodiment 2)
The difference from the first embodiment is that the first vibrator 2, the second vibrator 3, the switching means 13, the time measuring means 8, the storage means 9, the count difference detecting means 10, and the flow rate calculation. The operation of the control means 12 having the communication control means 15 for controlling at least one of the means 11 and communicating the value of the storage means 9 to the flow rate calculation means 11 in accordance with the value of the count difference detection means 10. That is, the storage medium 14 having a program for causing the computer to function reliably is used.

実施の形態１で示した制御手段１２の動作を行うには、予め実験等によりｔｘを求めるための受信点記憶手段の動作、通電方法を求めておいたり、経年変化、温度変化、システムの安定度に関して動作タイミングなどの相関を求め、ソフトをプログラムとして記憶媒体５９に格納しておく。   In order to perform the operation of the control means 12 shown in the first embodiment, the operation of the receiving point storage means for obtaining tx and the energization method are obtained in advance by experiments or the like, the secular change, the temperature change, the stability of the system Correlation such as operation timing with respect to the degree is obtained, and software is stored in the storage medium 59 as a program.

カウント差検出手段１０の閾値なども同様に格納しておく。通常マイクロコンピュータのメモリやフラッシュメモリ等電気的に書き込み可能なものにしておくと利用が便利である。切換手段４１の動作により送受信の方向が変化するため条件設定などの個数が増加してくるがこれをコンピュータによる動作で調整すると容易に実現可能である。   The threshold value of the count difference detecting means 10 is stored in the same manner. Usually, it is convenient to use an electrically writable memory such as a microcomputer memory or a flash memory. Since the direction of transmission / reception changes due to the operation of the switching means 41, the number of condition settings and the like increases.

このように、制御手段１２の動作をプログラムで行うことができるようになると流量演算の補正係数の条件設定、変更や計測間隔の調整などが容易にでき、また経年変化などにも柔軟に対応できるためよりフレキシブルに流速または流量計測の精度向上を行うことができる。   As described above, when the operation of the control means 12 can be performed by a program, it is possible to easily set, change, and adjust the measurement interval of the correction coefficient for the flow rate calculation, and to flexibly cope with aging. Therefore, the accuracy of flow velocity or flow rate measurement can be improved more flexibly.

なお、本実施の形態において、制御手段１２以外の動作もマイコン等によりプログラムで行ってもよい。   In the present embodiment, operations other than the control means 12 may be performed by a program using a microcomputer or the like.

これにより、制御手段としてコンピュータを機能させるためのプログラムを有する構成としたもので、測定方法の動作設定、変更が容易にでき、また、経年変化などにも柔軟に対応できるためよりフレキシブルに計測の精度向上を行うことができる。   As a result, it has a configuration that has a program for causing the computer to function as a control means, and can easily set and change the operation of the measurement method, and can flexibly cope with secular changes, etc. Accuracy can be improved.

本発明の、流速または流量計測装置は、流路内部を伝搬する物理信号の伝搬時間差が予め定めた時間以上発生する場合、特に流れの変化があった時に伝搬時間情報を流量演算手段に伝送する。   The flow velocity or flow rate measuring device of the present invention transmits propagation time information to the flow rate calculation means, particularly when there is a change in flow, when the propagation time difference of the physical signal propagating through the flow path occurs for a predetermined time or more. .

これにより、流れの変化があった時に伝搬時間情報を流量演算手段に伝送するようにして伝搬時間の情報伝達にかかる処理時間を短くすることができる。またそれ以外の条件では伝搬時間を伝送することを控えるため伝送時間の短縮や流量演算の簡素が可能になり、高精度な計測を実現しつつ、省電力動作を実現できる。   Thereby, the propagation time information is transmitted to the flow rate calculation means when there is a change in the flow, and the processing time required for the propagation time information transmission can be shortened. In addition, since transmission time is not transmitted under other conditions, transmission time can be shortened and flow rate calculation can be simplified, and power saving operation can be realized while realizing high-precision measurement.

１ 流路
２ 第１の振動子
３ 第２の振動子
４ 送信手段
５ 受信手段
７ 受信点検知手段
８ 計時手段
９ 記憶手段
１０ カウント差検出手段
１１ 流量演算手段
１２ 制御手段
１４ 記憶媒体
１５ 通信制御手段
１６ 閾値設定手段
１７ 第１のカウンタ
１８ 第２のカウンタ
２０ 通信選択手段
２１ 差分通信手段
２２ 異常確認手段
DESCRIPTION OF SYMBOLS 1 Flow path 2 1st vibrator | oscillator 3 2nd vibrator | oscillator 4 Transmission means 5 Reception means 7 Reception point detection means 8 Timekeeping means 9 Storage means 10 Count difference detection means 11 Flow rate calculation means 12 Control means 14 Storage medium 15 Communication control Means 16 Threshold setting means 17 First counter 18 Second counter 20 Communication selection means 21 Differential communication means 22 Abnormality confirmation means

Claims (7)

被測定流体の流れる流路内に物理信号を出力し、前記流路内を伝播した物理信号を入力する一対の物理信号入出力手段と、前記一方の物理信号入出力手段を駆動する送信手段と、前記他方の物理信号入出力手段で検知した信号を電気信号に変換する受信手段と、前記物理信号入出力手段の送受信の切換手段と、前記受信手段の信号を用いて物理信号出力手段から物理信号入力手段までの物理信号の伝播時間を計時する計時手段と、前記計時手段の値を記憶する記憶手段と、前記記憶手段の値の差が一定値以上かを判断するカウント差検出手段と、前記計時手段の計時差に基づいて流量を算出する流量演算手段と、前記物理信号入出力手段、送信手段、受信手段、切換手段、計時手段、記憶手段、カウント差検出手段、および流量演算手段の少なくとも１つを制御する制御手段とを備え、前記制御手段は前記カウント差検出手段の値に応じて前記記憶手段の値を前記流量演算手段に通信する通信制御手段を有する流体の流れ計測装置。 A pair of physical signal input / output means for outputting a physical signal into the flow path of the fluid to be measured and inputting the physical signal propagated in the flow path; and a transmission means for driving the one physical signal input / output means; A receiving means for converting the signal detected by the other physical signal input / output means into an electrical signal, a transmission / reception switching means for the physical signal input / output means, and a physical signal output means using the signal of the receiving means Timing means for timing the propagation time of the physical signal to the signal input means, storage means for storing the value of the timing means, count difference detection means for determining whether the difference between the values of the storage means is equal to or greater than a certain value, A flow rate calculating means for calculating a flow rate based on a time difference of the time measuring means, a physical signal input / output means, a transmitting means, a receiving means, a switching means, a time measuring means, a storage means, a count difference detecting means, and a flow rate calculating means. Small Control means for controlling at least one, and the control means has communication control means for communicating the value of the storage means to the flow rate calculation means in accordance with the value of the count difference detection means. . 計時手段は、基準時間を計測する第１のカウンタ、および詳細時間を計測する第２のカウンタを有し、記憶手段は前記前記第１のカウンタと前記第２のカウンタの出力を個々に記憶し、カウント差検出手段は前記記憶手段に個々に記憶した前記第１のカウンタと前記第２のカウンタの出力別に設けた請求項１記載の流体の流れ計測装置。 The time measuring means includes a first counter for measuring a reference time and a second counter for measuring a detailed time, and the storage means individually stores outputs of the first counter and the second counter. 2. The fluid flow measuring device according to claim 1, wherein the count difference detecting means is provided for each output of the first counter and the second counter individually stored in the storage means. 制御手段は、第１のカウンタと第２のカウンタの出力に対して個々に設けたカウント差検出手段の出力により差が発生している信号を記憶手段から流量演算手段に通信する通信制御手段の通信選択手段を設けた請求項１または２記載の流体の流れ計測装置。 The control means is a communication control means for communicating a signal in which a difference is generated by the output of the count difference detection means provided individually with respect to the outputs of the first counter and the second counter from the storage means to the flow rate calculation means. The fluid flow measuring device according to claim 1 or 2, further comprising a communication selection unit. 制御手段は、記憶手段の値を流量演算手段に通信する際に２回目以降は最初の記憶手段の値との差分のみを通信する差分通信手段を設けた請求項１記載の流体の流れ計測装置。 2. The fluid flow measuring device according to claim 1, wherein the control means is provided with a differential communication means for communicating only the difference from the value of the first storage means after the second time when communicating the value of the storage means to the flow rate calculation means. . 制御手段は、記憶手段の値を流量演算手段に通信する際に用いる差分通信手段は正の差分となるように記憶手段の通信する順序を入れ替えることが可能な構成とした請求項１記載の流体の流れ計測装置。 2. The fluid according to claim 1, wherein the control means is configured such that the order of communication of the storage means can be changed so that the difference communication means used when communicating the value of the storage means to the flow rate calculation means becomes a positive difference. Flow measuring device. カウント差検出手段は閾値設定手段を有し、前記閾値設定手段の値は変更可能とした請求項１記載の流体の流れ計測装置。 The fluid flow measuring device according to claim 1, wherein the count difference detecting unit includes a threshold setting unit, and the value of the threshold setting unit is changeable. 制御手段はカウント差検出手段の値が一定回数以上変化しない場合は計時手段の値を確認する異常確認手段を有する構成とした請求項１記載の流体の流れ計測装置。 2. The fluid flow measuring device according to claim 1, wherein the control means includes an abnormality confirmation means for confirming the value of the time measuring means when the value of the count difference detection means does not change more than a predetermined number of times.

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