JPS6053812A - Output-signal processing device of karman vortex sensor - Google Patents

Output-signal processing device of karman vortex sensor

Info

Publication number
JPS6053812A
JPS6053812A JP58160411A JP16041183A JPS6053812A JP S6053812 A JPS6053812 A JP S6053812A JP 58160411 A JP58160411 A JP 58160411A JP 16041183 A JP16041183 A JP 16041183A JP S6053812 A JPS6053812 A JP S6053812A
Authority
JP
Japan
Prior art keywords
flow rate
detecting
rectangular wave
wave signal
karman vortex
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.)
Pending
Application number
JP58160411A
Other languages
Japanese (ja)
Inventor
Masaki Mitsuyasu
正記 光安
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyota Motor Corp
Original Assignee
Toyota Motor Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Toyota Motor Corp filed Critical Toyota Motor Corp
Priority to JP58160411A priority Critical patent/JPS6053812A/en
Publication of JPS6053812A publication Critical patent/JPS6053812A/en
Pending legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01FMEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • G01F1/05Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects
    • G01F1/20Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow
    • G01F1/32Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by detection of dynamic effects of the flow using swirl flowmeters
    • G01F1/325Means for detecting quantities used as proxy variables for swirl
    • G01F1/3287Means for detecting quantities used as proxy variables for swirl circuits therefor

Landscapes

  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Physics & Mathematics (AREA)
  • Details Of Flowmeters (AREA)

Abstract

PURPOSE:To accelerate the updating of flow rate data and to enhance the detecting accuracy of the flow rate, by guiding the output signal of a Karman vortex sensor to a pair of period detecting means through a waveform shaping means, detecting the periods corresponding to the rise and fall of a rectangular signals, and computing the flow rate from the periods. CONSTITUTION:The output signal with frequency corresponding to the flow rate from a Karman vortex sensor 31 in a sine wave shape is converted into a rectangular signal by a waveform shaping circuit 32. The signal is supplied to a rise-up detecting circuit 33 and a fall-down detecting circuit 34. Their output signals are supplied to interruption inputs of a CPU35. Counters 37 and 38 count the periods corresponding to the rise up and fall down of the rectangular waves, respectively. The period signals are inputted to the CPU35, where the flow rate is computed. Therefore, the updating of the flow rate data is accelerated, and the detecting accuracy of the flow rate is enhanced.

Description

【発明の詳細な説明】 技術分野 本発明はたとえばエンジンの吸入空気量を測定するため
のエアフローメータとして用いられる力(1) ルマン渦センサの出力信号処理装置に関する。
DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an output signal processing device for a force (1) Le Mans vortex sensor used, for example, as an air flow meter for measuring the intake air amount of an engine.

従来技術 一般に、エンジンの吸入空気量を測定するためのエアフ
ローメータとしてはベーン式流量計が主流であったが、
最近、小型等の利点を有するカルマン渦センサが開発さ
れつつある。カルマン渦センサにおいては、たとえば、
特開昭58−80524号および特開昭58−8052
5号に示すように、流体が流れる管路内にカルマン渦発
生体を挿入し、そのカルマン渦発生体の両側面近傍に交
互に発生ずる圧力変動を1対の圧力伝達通路を介して管
路外の振動板に伝達し、この振動板の回転変位を光電的
に検出することにより流体の速度を検出している。この
場合、振動板の回転変位に応じた正弦波状の電気信号を
得、これを矩形波信号に変換させ、この矩形波信号の各
パルス周期を検出することによって流体の速度を得てい
る。従来、上述の矩形波信号の各パルス周期を検出する
場合、立上り周期もしくは立下り周期のいずれか一方の
みを検出していたために、特に周期の長い低流量測定領
域では(2) 流量データの更新が遅く、流量検出粘度が低いとい・う
問題点があった。
Conventional technology In general, vane flowmeters have been the mainstream airflow meters for measuring the amount of intake air in engines.
Recently, Karman vortex sensors have been developed which have advantages such as small size. In the Karman vortex sensor, for example,
JP-A-58-80524 and JP-A-58-8052
As shown in No. 5, a Karman vortex generator is inserted into a pipe through which fluid flows, and the pressure fluctuations generated alternately near both sides of the Karman vortex generator are transferred to the pipe via a pair of pressure transmission passages. The velocity of the fluid is detected by transmitting the signal to an external diaphragm and photoelectrically detecting the rotational displacement of this diaphragm. In this case, a sinusoidal electrical signal corresponding to the rotational displacement of the diaphragm is obtained, this is converted into a rectangular wave signal, and the velocity of the fluid is obtained by detecting each pulse period of this rectangular wave signal. Conventionally, when detecting each pulse period of the above-mentioned rectangular wave signal, only either the rising period or the falling period was detected, so especially in the low flow rate measurement area where the period is long, (2) Update of flow rate data The problem was that the flow rate was slow and the flow rate detection viscosity was low.

発明の目的 本発明の目的は、−上述の従来形の問題点に鑑の、パル
スの立1−り周期および立下り周期の両方を検出するご
とにより、周期が長い低流量測定領域でも流Vデータの
更新を早め、流量検出精度を高めるごとにある。
OBJECTS OF THE INVENTION An object of the present invention is to: - In view of the above-mentioned problems with the conventional method, it is possible to detect the flow rate V even in a low flow rate measurement region with a long period by detecting both the rising and falling periods of the pulse. Each time the data is updated faster and the accuracy of flow rate detection is improved.

発明の構成 −L述のl」的を達成するだめの本発明の構成は第1図
にポされる。第1図において、カルマン渦センリーし、
1流体の流量に応じた周波数の出力信号を発/I: L
、、波形整形手段番、1カルマン渦センザの出力信1J
を波形整形して矩形波信号を発生ずる。立上り検出り段
(31矩形波信%Jの)fにりを検出し、他方、1′L
l−′り検出手段IJ: X、lj形波信号の立下りを
検出する。
Structure of the Invention - The structure of the present invention to achieve the above objectives is shown in FIG. In Figure 1, the Karman vortex center,
1 Generates an output signal with a frequency according to the flow rate of fluid/I: L
,, Waveform shaping means number, 1 Karman vortex sensor output signal 1J
The waveform is shaped to generate a rectangular wave signal. The rising edge detection stage (of 31 rectangular wave signal %J) detects the rising edge, and on the other hand, the 1'L
l-' detection means IJ: Detects the falling edge of the X, lj wave signal.

また、第1の周期検出手段は矩形波信号の立−1りに応
じて矩形波信’1jO)−周期、つまり、立」二り周期
を検出し、他方、第2の周期検出手段は矩形波信号の立
下りに応U7て矩形波信号の一周期、つま(3) り立下り周期を検出する。そして、第1.第2の周期検
出手段によって検出された周期を用いて流量演算手段は
流体の流量を演算する。
Further, the first period detecting means detects the rectangular wave signal '1jO)- period, that is, the two rising periods, in response to the rising -1 of the rectangular wave signal, while the second period detecting means detects the rectangular In response to the falling edge of the wave signal, U7 detects one period of the rectangular wave signal, that is, the falling period (3). And the first. The flow rate calculation means calculates the flow rate of the fluid using the period detected by the second period detection means.

実施例 以下、第2図以降の図面を参照して本発明の詳細な説明
する。
EXAMPLES Hereinafter, the present invention will be described in detail with reference to FIG. 2 and subsequent drawings.

第2図(A)はカルマン渦センサの一例を示す断面図で
ある。第2図(A)において、管路1内の中央に渦発生
体2が設けられており、この渦発生体2には、一対の温
圧取入孔3と、この取入孔3の圧力変動を管路1外に伝
達する圧力伝達通路4とが設けられている。この結果、
圧力伝達通路4の圧力変動によって振動板5に回転モー
メントが生じる。
FIG. 2(A) is a sectional view showing an example of a Karman vortex sensor. In FIG. 2(A), a vortex generator 2 is provided at the center of the pipe 1, and this vortex generator 2 has a pair of temperature pressure intake holes 3 and a pressure A pressure transmission passage 4 for transmitting fluctuations to the outside of the pipe line 1 is provided. As a result,
A rotational moment is generated in the diaphragm 5 due to pressure fluctuations in the pressure transmission passage 4 .

なお、振動板5は、第2図(B)に示すように、一対の
スパンバンド6a 、 6bによってその重心を含む回
転軸上に支持され、さらに、スパンパンF’6a。
As shown in FIG. 2(B), the diaphragm 5 is supported on a rotation axis including its center of gravity by a pair of span bands 6a and 6b, and further includes a span band F'6a.

6bは枠部7に保持されている。従って、振動板5は外
部振動による枠部7の上下振動ではほとんど振動せず、
従って、カルマン渦による圧力伝達通(4) +I8 、I内の圧力変4!11のめに応じて回転振動
することになる。
6b is held by the frame portion 7. Therefore, the diaphragm 5 hardly vibrates due to the vertical vibration of the frame 7 caused by external vibration.
Therefore, the pressure transmission channel (4) +I8 by the Karman vortex rotates and oscillates in response to the pressure change 4!11 in I.

第2図(A>において、8は発光手段としての発光ダイ
オ−1゛、1)は受光手段としてのフォトダイオードで
ある。つまり、この場合、振動板5が光の反射板として
作用し、従って、カルマン渦圧によって振動板5が回転
振動すると、フォトダイオ−]−9の出力信号は渦周波
数fの正弦波状吉なる。本発明はフォトダイオード9の
正弦波状の出力信号の処理に関するものである。
In FIG. 2 (A>), 8 is a light emitting diode 1' as a light emitting means, and 1 is a photodiode as a light receiving means. That is, in this case, the diaphragm 5 acts as a light reflecting plate, and therefore, when the diaphragm 5 rotates and vibrates due to the Karman vortex pressure, the output signal of the photodiode 9 becomes a sine wave with a vortex frequency f. The present invention relates to processing of the sinusoidal output signal of the photodiode 9.

第3図ぼ本発明に係るカルマン渦センサの出力信号処理
装置の一実施例を示す回路図であって、たとえばマイク
l:1.’7ンピユータによって構成されζいるもので
ある。なお、第3図において、1点鎖線にて囲まれた部
分はマイクロコンピュータとして構成されるが、波形整
形回路32はカルマン渦センザ31内に設けてもよい。
FIG. 3 is a circuit diagram showing an embodiment of an output signal processing device for a Karman vortex sensor according to the present invention, for example, a microphone l:1. It is composed of 7 computers. In FIG. 3, the portion surrounded by the dashed line is configured as a microcomputer, but the waveform shaping circuit 32 may be provided within the Karman vortex sensor 31.

カルマン渦センリー31の正弦波状の出力信号は波形整
形回路32に供給され、ここで、正弦波状信号は矩形波
信νJに変換される。この矩形波信号(5) は立上り検出回路33および立下り検出回路34に供給
され、これら2つの回路33 、34の出力信号はCP
U 35の1つの割込み入力に供給される。この結果、
CPU 35は矩形波信号の立上りおよび立下りの両方
に応じて後述の第4図に示す割込みルーチンを実行する
。36は各種のクロック信号を発生するクロック発生回
路、37 、38は波形整形回路32の矩形波信号の一
周期を検出するためのカウンタである。たとえば、カウ
ンタ37は矩形波信号の立上り周期を検出するためのも
のであり、カウンタ38は矩形波信号の立下り周期を検
出するためのものである。39は入出力インターフェイ
ス40はプログラム、定数等を予め記憶するROM、4
1はデータを一時的に記憶するRAMである。
The sinusoidal output signal of the Karman vortex sensor 31 is supplied to a waveform shaping circuit 32, where the sinusoidal signal is converted into a rectangular wave signal νJ. This rectangular wave signal (5) is supplied to a rise detection circuit 33 and a fall detection circuit 34, and the output signals of these two circuits 33 and 34 are CP
Provided to one interrupt input of U35. As a result,
The CPU 35 executes an interrupt routine shown in FIG. 4, which will be described later, in response to both rising and falling edges of the rectangular wave signal. 36 is a clock generation circuit that generates various clock signals, and 37 and 38 are counters for detecting one cycle of the rectangular wave signal of the waveform shaping circuit 32. For example, the counter 37 is for detecting the rising cycle of the rectangular wave signal, and the counter 38 is for detecting the falling cycle of the rectangular wave signal. 39 is an input/output interface 40 is a ROM that stores programs, constants, etc. in advance;
1 is a RAM that temporarily stores data.

第4図は第3図の回路動作を説明するためのフローチャ
ートであって、吸入空気量演算ルーチンである。割込み
ステップ401は第5図(A)に示すような波形整形回
路32の矩形波信号の立上りによってスタートし、ステ
ップ402ではフラグFが“1″か否かを判別する。た
とえば、F=“1°゛(6) であればステップ403にてフラグFをクリアし、ステ
ップ404にてカウンタ37の値TOFXを取込み、次
の演算り・イクルのためにカウンタ37をリセットする
。この場合、カウンタ37の値TQFXは第5図(A)
に示す矩形波信号の周期T(IFXO、TQFX2 。
FIG. 4 is a flowchart for explaining the circuit operation of FIG. 3, and is an intake air amount calculation routine. The interrupt step 401 starts with the rise of the rectangular wave signal of the waveform shaping circuit 32 as shown in FIG. 5(A), and in step 402 it is determined whether the flag F is "1" or not. For example, if F = "1°" (6), the flag F is cleared in step 403, the value TOFX of the counter 37 is taken in in step 404, and the counter 37 is reset for the next calculation/cycle. In this case, the value TQFX of the counter 37 is as shown in FIG.
The period T (IFXO, TQFX2) of the rectangular wave signal shown in

・・・の1つに相当する。次に、ステップ407にて値
T叶にを用いて吸入空気1iQを Q←−に/TQFX ただし、Kは定数 によって演嘗し、ステップ408にてこのルーチンは終
γする。
Corresponds to one of... Next, in step 407, the value T is used to change the intake air 1iQ to Q←-/TQFX, where K is manipulated by a constant, and in step 408, this routine ends γ.

再び第4図のルーチンが実行されると、F=“0゛′で
あるのでステップ402からステップ403へのフロー
はステップ402からステップ405へのフローに切替
わる。ステップ405にてフラグFを立て、ステップ4
06にてカウンタ38の値TQFXを取込め、次の演算
サイクルのためにカウンタ38をリセットする。この場
合、カウンタ38の値T叶Xは第5図(A)に示す矩形
波信号の周期T叶×I 、T叶X3 、・・・の1つに
相当する。
When the routine of FIG. 4 is executed again, since F="0'', the flow from step 402 to step 403 is switched to the flow from step 402 to step 405. In step 405, flag F is set. , step 4
At 06, the value TQFX of the counter 38 is taken, and the counter 38 is reset for the next calculation cycle. In this case, the value T of the counter 38 corresponds to one of the periods T of the rectangular wave signal shown in FIG. 5(A), T of the rectangular wave signal shown in FIG.

(7) このようにして、ステップ404とステップ406とが
交互に実行されることになる。従って、計測された周期
は第5図(B)の実線のごとく変化し、周期検出精度が
高くなる。なお、第5図(B)の点線はたとえば立上り
周期を計測した従来形を示す。
(7) In this way, step 404 and step 406 are executed alternately. Therefore, the measured period changes as shown by the solid line in FIG. 5(B), and the period detection accuracy becomes high. Note that the dotted line in FIG. 5(B) shows, for example, a conventional type in which the rising cycle is measured.

発明の効果 以−ト説明したように本発明によれば、パルスの立上り
周期および立下り周期の両方を検出しているので、周期
が長い低流量測定領域でも流量検出精度を高めることが
でき、カルマン渦センサを内燃機関のエアフローメータ
として用いた場合には空燃比制御が改善され、アイドリ
ングの安定性等に役立つものである。
Effects of the Invention As explained above, according to the present invention, since both the rising and falling cycles of the pulse are detected, the flow rate detection accuracy can be improved even in the low flow rate measurement region where the cycle is long. When the Karman vortex sensor is used as an air flow meter for an internal combustion engine, air-fuel ratio control is improved, which is useful for idling stability and the like.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は本発明の構成を示すブロック図、第2図(A)
はカルマン渦センナの一例を示す断面図、第2図(B)
は第2図(A)の振動板5の平面図、第3図は本発明に
係るカルマン渦センサの出力信号処理装置の一実施例を
示す回路図、第4図は第(8) 3図の回路動作を説明するだめのフローチャート、第5
図(Δ) 、U3)は第4図のフローチャー1・の補足
説明を示すタイミング図である。 l:管路、2:渦発生体、3:渦圧取入孔、4:圧力伝
達油1−8.5:振動板、8:発光手段、9:受光手段
、31:カルマン渦センサ、32:波形整形回1714
゜ 特許出願人 ]・ヨタ自動車株式会社 特許出願代理人 弁理士 青 木 朗 弁理士西舘和之 弁理士 山 口 昭 之 弁理士西山雅也 (9) 63
Figure 1 is a block diagram showing the configuration of the present invention, Figure 2 (A)
is a cross-sectional view showing an example of a Karman vortex senna, Figure 2 (B)
is a plan view of the diaphragm 5 in FIG. 2(A), FIG. 3 is a circuit diagram showing an embodiment of the output signal processing device of the Karman vortex sensor according to the present invention, and FIG. 4 is a plan view of the diaphragm 5 in FIG. A flowchart explaining the circuit operation of
Figure (Δ), U3) is a timing diagram showing supplementary explanation of flowchart 1 in Figure 4. l: pipe line, 2: vortex generator, 3: vortex pressure intake hole, 4: pressure transmission oil 1-8.5: diaphragm, 8: light emitting means, 9: light receiving means, 31: Karman vortex sensor, 32 : Waveform shaping episode 1714
゜Patent applicant] Yota Jidosha Co., Ltd. Patent agent Akira Aoki Patent attorney Kazuyuki Nishidate Patent attorney Akira Yamaguchi Patent attorney Masaya Nishiyama (9) 63

Claims (1)

【特許請求の範囲】[Claims] 1、流体の流量に応じた周波数の出力信号を発生するカ
ルマン渦センサ、該カルマン渦センサの出力信号を波形
整形して矩形波信号を発生する波形整形手段、該矩形波
信号の立上りを検出する立上り検出手段、前記矩形波信
号の立下りを検出する立下り検出手段、前記矩形波信号
の立上りに応じて該矩形波信号の一周期を検出する第1
の周期検出手段、前記矩形波信号の立下りに応じて該矩
形波信号の一周期を検出する第2の周期検出手段、およ
び、該検出された周期を用いて前記流体の流量を演算す
る流量演算手段を具備するカルマン渦センサの出力信号
処理装置。
1. A Karman vortex sensor that generates an output signal with a frequency corresponding to the flow rate of fluid, a waveform shaping means that shapes the output signal of the Karman vortex sensor to generate a rectangular wave signal, and detects the rise of the rectangular wave signal. a rising edge detecting means, a falling detecting means for detecting a falling edge of the rectangular wave signal, a first detecting means for detecting one cycle of the rectangular wave signal in response to a rising edge of the rectangular wave signal;
period detection means, second period detection means for detecting one period of the rectangular wave signal according to the fall of the rectangular wave signal, and a flow rate for calculating the flow rate of the fluid using the detected period. An output signal processing device for a Karman vortex sensor, comprising calculation means.
JP58160411A 1983-09-02 1983-09-02 Output-signal processing device of karman vortex sensor Pending JPS6053812A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP58160411A JPS6053812A (en) 1983-09-02 1983-09-02 Output-signal processing device of karman vortex sensor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP58160411A JPS6053812A (en) 1983-09-02 1983-09-02 Output-signal processing device of karman vortex sensor

Publications (1)

Publication Number Publication Date
JPS6053812A true JPS6053812A (en) 1985-03-27

Family

ID=15714351

Family Applications (1)

Application Number Title Priority Date Filing Date
JP58160411A Pending JPS6053812A (en) 1983-09-02 1983-09-02 Output-signal processing device of karman vortex sensor

Country Status (1)

Country Link
JP (1) JPS6053812A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3623262A1 (en) * 1985-07-16 1987-01-29 Toyota Motor Co Ltd FLOW MEASURING SYSTEM WITH A KARMAN SWIRL FLOW METER

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS49114475A (en) * 1973-02-28 1974-10-31
JPS52146279A (en) * 1976-05-26 1977-12-05 Bosch Gmbh Robert Circuit for continuously measuring pulse repetition frequency

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS49114475A (en) * 1973-02-28 1974-10-31
JPS52146279A (en) * 1976-05-26 1977-12-05 Bosch Gmbh Robert Circuit for continuously measuring pulse repetition frequency

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3623262A1 (en) * 1985-07-16 1987-01-29 Toyota Motor Co Ltd FLOW MEASURING SYSTEM WITH A KARMAN SWIRL FLOW METER
US4819490A (en) * 1985-07-16 1989-04-11 Toyota Jidosha Kabushiki Kaisha Karman vortex sensor type flow rate measuring system

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