JP2004333428A - Fluid flow measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To heighten voltage stability by operating a boosting means after elapse of a fixed time after makeup of a power supply, because there is a possibility of generating malfunction of another circuit operation when a voltage is not yet stabilized in the initial stage of system operation in operation of the boosting means. <P>SOLUTION: A power supply control means 44 transmits a signal to the boosting means 43 to adjust the voltage after elapse of the fixed time after makeup of the power supply, to thereby perform power supply to an oscillator with a stabilized voltage, and the operation of the boosting means not exerting an influence such as a noise on the system can be realized by operating the boosting means 22 during a period when the load operation is not influenced. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fluid flow measuring device that uses a boosting means for supplying power having a voltage higher than a power supply voltage to a load and measures the flow velocity and / or flow rate of gas or liquid using ultrasonic waves.
[0002]
[Prior art]
As a conventional boosting means, there is one using a DCDC converter, and a flow rate measuring device using this is an electrical measurement method using ultrasonic waves (see, for example, Patent Document 1).
[0003]
FIG. 11 shows a configuration of a general booster circuit, where 1 is a power source, 2 is a DCDC converter, 3 is an inductance L, 4 is a diode D, 5 is a capacitor C, and 6 is a load.
[0004]
In the DC-DC converter 2, the back electromotive force generated in the inductance is rectified through the diode 4 when the inductance 3 is switched from on to off by switching the inductance 3, and a stable high voltage in which the ripple is reduced by the capacitor 5 is applied to the load 6. To supply.
[0005]
FIG. 12 shows a conventional ultrasonic flowmeter, in which a first ultrasonic transducer 12 for transmitting ultrasonic waves and a second ultrasonic transducer 13 for receiving are arranged in the flow direction in the middle of the fluid flow path 11.
[0006]
Reference numeral 14 denotes a transmission circuit to the first ultrasonic transducer 12, and reference numeral 15 denotes a reception circuit that performs signal processing on the ultrasonic waves received by the second ultrasonic transducer 13. Reference numeral 16 denotes a repeating unit that repeats transmission from the first ultrasonic transducer 12 and reception by the second ultrasonic transducer 13 a plurality of times after the reception circuit 15 detects the ultrasonic waves.
[0007]
Reference numeral 17 denotes delay time generating means for generating a delay time until ultrasonic waves are transmitted again from the first ultrasonic transducer 12 after detecting the ultrasonic wave by the receiving circuit, and 18 is generated by the delay time generating means 17. A delay time measuring means for measuring the delay time, 19 is a delay time control means for controlling the delay time based on the measured value of the delay time generating means 17, and 20 is a requirement for a plurality of times of ultrasonic transmission performed by the repetition means. An accumulated time measuring means 21 for measuring time is a flow rate calculating means 21 for obtaining a flow rate from the measured values of the delay time measuring means 18 and the accumulated time measuring means 20.
[0008]
The ultrasonic signal transmitted from the first ultrasonic transducer 12 by the burst signal transmitted from the transmission circuit 14 propagates in the flow, is received by the second ultrasonic transducer 13, and is detected by the reception circuit 15. After the delay time generated by the delay time generating means 17 is set, the burst signal is transmitted again from the transmission circuit 14.
[0009]
The burst signal from the transmission circuit 14 is repeated a predetermined number of times, and the time required for this repetition is measured by the accumulated time measuring means 20 and the delay time is measured by the delay time measuring means 10.
[0010]
Further, the flow rate calculating means 21 obtains the required time T for only transmitting ultrasonic waves by subtracting the delay time obtained by the delay time measuring means 19 from the value obtained by the accumulated time measuring means 20.
[0011]
Normally, when driving a vibrator from this transmission circuit, a high voltage is supplied in consideration of the signal attenuation due to the propagation distance. As the circuit, the booster circuit described above is often used.
[0012]
[Patent Document 1]
JP 2000-292232 A (2nd page, FIG. 1)
[0013]
[Problems to be solved by the invention]
However, in the conventional high voltage supply circuit in the booster circuit, the operation timing of the DCDC converter considering the operation of the load and the stability of the entire circuit is not unified, and operates individually.
[0014]
For example, if the operation of the DCDC converter is started before the supply voltage to the transmission / reception circuit is stabilized, there is a possibility that waste will occur in the time after the charging until the load operates. Further, if the booster circuit operates during the initial setting operation of the circuit, the system voltage may fluctuate, or the measurement accuracy may be degraded due to the generation of noise.
[0015]
The present invention solves the above-mentioned problem. By controlling the boosting means frequently, power is supplied to the load with a stable voltage, and the operation of the boosting means does not affect the system such as noise. The purpose is to realize.
[0016]
An object of the present invention is to realize accurate flow velocity and / or flow rate measurement that realizes stable operation of the measurement system by using such a stable boost control means.
[0017]
[Means for Solving the Problems]
In order to solve the above-described conventional problems, a fluid flow measurement device according to the present invention includes a pair of ultrasonic transducers that are arranged in a flow path of a fluid to be measured and that transmits and receives ultrasonic waves, and drives these ultrasonic transducers. Transmitting means, receiving means for converting the output signal of the receiving ultrasonic transducer into an electrical signal, transmission / reception switching means for the ultrasonic transducer, and ultrasonic propagation between the ultrasonic transducers a plurality of times. Repetitive means for performing, a delay means for delaying a transmission signal from the ultrasonic transducer during the repetition, a time measuring means for measuring a propagation time of each of a plurality of repetitions, and a time difference between the time measured values by the time measuring means Calculation means for calculating the flow velocity and / or flow rate, a power supply, a boosting means for generating a higher voltage than the power supply, and a power supply control means for controlling the power supply and the boosting means, for the operation of the entire circuit and the operation of the load. According It is obtained so as to control the increase in operation voltage by diligently boosting means.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention includes a pair of ultrasonic transducers that are arranged in a flow path through which a fluid to be measured flows and that transmits and receives ultrasonic waves, a transmission unit that drives these ultrasonic transducers, and a reception-side ultrasonic transducer. A receiving means for converting an output signal into an electric signal; a transmission / reception switching means for the ultrasonic vibrator; a repeating means for performing ultrasonic propagation between the ultrasonic vibrators a plurality of times; and A delay means for delaying the transmission signal, a time measuring means for measuring the propagation time of each of the plurality of repetitions, a calculating means for calculating a flow velocity and / or a flow rate based on a difference between the respective time measured values by the time measuring means, and a power source And a boosting means for generating a higher voltage than the power supply, and a power supply control means for controlling the power supply and the boosting means.
[0019]
By ensuring the power supply voltage that stabilizes the circuit operation and controlling the voltage according to the operation of the load, power is supplied to the load at a stable voltage, and noise and other effects are given to the system. Thus, it is possible to realize the operation of the boosting means, to realize a stable operation of the measurement system, and to realize accurate flow velocity and / or flow rate measurement.
[0020]
The boosting means is operated after the power supply control means stabilizes the power supply output, so that the output voltage of the power supply is stabilized, the circuit voltage of each part is determined, and the boosting means can be operated after the steady operation is performed. It is possible to improve the stability of both the operation and the peripheral circuit.
[0021]
Also, by operating the booster after the power supply control unit has passed the power supply output for a certain time, the booster can operate after the initial operation is completed after the output voltage of the power supply is stabilized and the circuit voltage of each part has been determined. And the stability of both peripheral circuits can be improved.
[0022]
In addition, the power supply control means stops the operation of the boosting means when the output voltage of the boosting means reaches a predetermined value, thereby shortening the operation time of the boosting means and cutting down unnecessary power and shortening the noise generation time and saving power. Operation becomes possible.
[0023]
In addition, the power supply control means stops the operation of the boosting means before the operation of the transmission means is started, and the operation of the boosting means is terminated before the operation of the load, so that the high voltage is always applied when the load is operated. It is possible to perform power saving operation while keeping the supply state possible and shortening the operation time of the boosting means.
[0024]
Further, the power supply control means stops the operation of the boosting means after a certain time has elapsed after the operation of the transmission means is completed, so that the transmission operation can be performed at a stable voltage, and then the operation is stopped after a sufficient boosting operation is performed. This makes it possible to prepare for the next operation.
[0025]
Furthermore, it is configured to have a program for causing the computer to function to ensure the operation of the power supply control means, thereby making it possible to easily set and change the operation of the boosting means, and to flexibly with aging etc. Since it can respond, the accuracy of the boosted output voltage can be improved more flexibly.
[0026]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0027]
Example 1
In FIG. 1, a first ultrasonic transducer 32 and a second ultrasonic transducer 33 that transmit and receive ultrasonic waves are installed in a flow path 31 through which a fluid to be measured flows.
[0028]
In addition, a transmission unit 34 for driving the first ultrasonic transducer 32 and a reception unit 35 for receiving a reception signal of the second ultrasonic transducer 33 and determining a reception timing are provided, and the transmission unit 34 and the first ultrasonic transducer 32, and between the second ultrasonic transducer 33 and the receiving unit 35, a switching unit 36 is provided to transmit and receive ultrasonic waves to and from the first ultrasonic transducer 32 and the first ultrasonic transducer 32. The two ultrasonic transducers 33 are alternately arranged.
[0029]
Receiving the output of the receiving means 35, measuring the number of operations of repeating the transmission / reception of the ultrasonic wave again via the transmitting means 34, and the repeating means 37 for stopping the operation at a predetermined number of times, and receiving the signal of the repeating means 37 A delay means 38 that outputs a trigger signal of the transmission means 34 with a delay of the delay time, and at least the propagation time of the ultrasonic wave from the start of driving of the first vibrator 32 by the transmission means 34 to the stop of the operation of the repeat means 37. It has a time measuring means 39 for measuring, and a calculating means 40 for calculating the flow velocity from the value of the time measuring means 39 and obtaining the flow rate therefrom.
[0030]
Further, a measurement control unit 41 is provided, and a measurement start signal for operating the transmission unit 34 is output.
[0031]
Furthermore, a power source 42 for supplying power, a booster unit 43 for driving a load having a higher voltage than the power source, and a power source controller 44 for controlling the power source and the booster unit are provided.
[0032]
Normal operation will be described. Upon receipt of the start signal from the measurement control means 41, the transmission means 34 drives the first ultrasonic transducer 32 with a pulse for a certain period of time, and at the same time, the time measurement means 39 starts measuring time in accordance with the signal from the measurement control means 41.
[0033]
Ultrasound is transmitted from the pulse-driven first ultrasonic transducer 32. The ultrasonic wave transmitted from the first ultrasonic transducer 32 propagates through the fluid to be measured and is received by the second ultrasonic transducer 33.
[0034]
The reception output of the second ultrasonic transducer 33 amplifies the signal by the receiving means 35 and then determines the reception of the ultrasonic wave at the signal level at a predetermined reception timing. When the repeated operation is not performed, the operation of the time measuring means 39 is stopped when the reception of the ultrasonic wave is determined, and the flow velocity is obtained from the time information t by (Equation 1).
[0035]
(The measurement time obtained from the time measuring means 39 is t, the effective distance in the flow direction between the ultrasonic transducers is L, the sound velocity is c, and the flow velocity of the fluid to be measured is v).
[0036]
v = (L / t) -c (Formula 1)
The receiving means 35 is usually configured to compare the reference voltage and the received signal by a comparator.
[0037]
In the current operation using the repeating unit 37, the determination result of the receiving unit 35 is delayed by a delay unit 38 for a certain period of time, then returned to the transmitting unit 34 and transmitted again. The repetitive operation is performed a predetermined number of times, the time is measured by the time measuring means 39, and the flow velocity is obtained by the calculation of (Equation 2) based on the measurement time of the time measuring means 39.
[0038]
The delay time of the delay means is Td, the number of repetitions is n, the measurement time is ts, the effective distance in the flow direction between the ultrasonic transducers is L, the sound velocity is c, and the flow velocity of the fluid to be measured is v.
[0039]
v = L / (ts / n−Td) −c (Expression 2)
According to this method, it is possible to measure with higher accuracy than the method of (Equation 1).
[0040]
Further, the first ultrasonic transducer 32 and the second ultrasonic transducer 33 are switched, and the respective propagation times of the fluid under measurement from upstream to downstream and from downstream to upstream are measured. Find v.
[0041]
Note that the measurement time from upstream to downstream is t1, and the measurement time from downstream to upstream is t2.
[0042]
v = L / 2 ((1 / t1)-(1 / t2)) (Formula 3)
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, the flow rate, the 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 1.
[0043]
Normal operation is as shown in the timing diagram of FIG. That is, measurement is started from the start signal at time t0 by the measurement control means 41, and the first ultrasonic transducer 32 is driven via the transmission means 34 at t1.
[0044]
The ultrasonic signal generated there propagates in the flow path, reaches the second ultrasonic transducer 33 at time t2, and when the receiving means 35 detects the reception point, the repeating means 37 has not reached the set number of times. A signal is sent to the delay means 38.
[0045]
Then, the delay means 38 starts operating from time t3, operates for a predetermined time, and then sends a signal to the transmitting means 34 at time t4 to drive the first ultrasonic transducer 32 again. This is repeated below.
[0046]
When the number of times determined by the repeat means 37 is operated, the transmission / reception operation is stopped at time t5, and the time is T. Thereafter, the switching means 36 switches between transmission and reception. That is, the first ultrasonic transducer 32 is on the receiving side, and the second ultrasonic transducer 33 is on the transmitting side. Then, the same repeated operation is performed.
[0047]
Next, the vicinity of the power source that supplies power to the measurement control means 41 and the like will be described with reference to FIG.
[0048]
42 is a power supply, 43 is a boosting means, 44 is a power supply control means, and 45 is a load. As an example of the boosting means 43, it can be constituted by an inductance 43a, an opening / closing means 43b, a diode 43c, and an opening / closing control means 43d.
[0049]
When the control means 44 detects the operation of the load 45, it sends a signal to the opening / closing control means 43d, and the opening / closing control means 43d turns on / off the opening / closing means 43b.
[0050]
As a result, the current flowing from the power source 42 via the inductance 43a becomes intermittent, so that the counter electromotive force of the inductance 43a is supplied to the load 45 through the diode 43c.
[0051]
As a configuration showing another operation by the power supply control unit 44, the operation of the load 45 may be detected by the power supply control unit 44.
[0052]
If the terminal voltage of the load 45 is converted into a voltage signal by resistance division or the like and the signal enters the open / close control means 43d inside the boost means 43, the open / close means can be operated based on the voltage information to control the boost voltage.
[0053]
Further, the output voltage is measured by the power supply control means 44, and the power supply control means 44 sends a signal for adjusting the opening / closing means 43b so as to make the output voltage of the boosting means 43 constant, for example, by obtaining a voltage signal by an AD converter or the like. To do.
[0054]
In this way, the power supply control unit 44 detects the operation of the load 45, sends a signal to the boosting unit 43 according to the operation and adjusts the voltage, thereby supplying power to the load 45 with a stable voltage. By operating the boosting means 43 at a time when it does not affect the operation of the load, it is possible to realize the operation of the boosting means so as not to affect the system due to noise or the like.
[0055]
Further, step-down means 43e for stepping down the power supply voltage and a power supply path directly connected to the power supply voltage may be added.
[0056]
A difference from the conventional example will be described with reference to the timing of FIG. FIG. 4A shows the operation timing of the load in the DCDC converter 2 which is a conventional booster circuit. When the load operates, the output voltage of the booster 2 decreases as shown in (b). Then, it is detected that the voltage has dropped at t1, and the DCDC converter operates. The timing of t1 is determined only by the voltage and does not consider the operation of the load.
[0057]
Therefore, as shown in FIG. 4, even when the voltage drops while the load 6 is operating, the DCDC converter immediately starts the boosting operation. This indicates that the terminal voltage of the load fluctuates during operation.
[0058]
If it is used in a measuring device, the operating voltage fluctuates and the stability becomes worse. Similarly, FIG. 4C shows the operation timing of the load when the power supply control means 44 of the present invention is used.
[0059]
(D) shows the operation timing of the power supply control means 44. Since the power supply control means 44 detects the operation of the load 6, when the load operation ends, a signal is sent to the boosting means 43 at times t3 and t4 to adjust the opening / closing means to perform the boosting operation.
[0060]
Accordingly, the output voltage of the boosting means 43 is as shown in FIG. 2E, and the voltage can be changed by removing the operation timing of the load.
[0061]
The case where the power supply control means 44 is incorporated in the flow rate measuring device as shown in FIG. 5 will be described.
[0062]
In order to drive the first ultrasonic transducer 32, it is necessary to drive the flow path 31 at a certain high voltage in order to transmit the inside of the flow path 31 at a sufficient ultrasonic signal level. Therefore, the output of the booster 43 is connected to the first vibrator 32 via the transmitter 34.
[0063]
Since the switching means 36 on the way only switches between transmission and reception, a detailed description here is omitted.
[0064]
As an example of the inside of the transmission means 34, a bridge configuration using transmission opening / closing means 34a to 34d is used to operate the ultrasonic transducer. First, the transmission opening / closing means 34a and 34d are energized, and on the contrary, 34b and 34c are opened.
[0065]
Next, the transmission opening / closing means 34a and 34d are opened, and 34b and 34c are energized. With this operation, the ultrasonic transducer starts to operate. A high voltage from the booster 43 is supplied to the power source for the ultrasonic transducer.
[0066]
As shown in FIG. 4B, when this high voltage is supplied, regardless of the operating state of the load (in this case, the ultrasonic transducer), if the boosting operation is performed only by the DCDC converter, The supply voltage changes during operation, and the received signal is not constant. This is not preferable because it greatly affects the measurement accuracy of the flow rate.
[0067]
As shown in FIGS. 4D and 4E, the power supply control unit 44 detects the operation of the boosting unit 43 and the operation of the ultrasonic transducer 32, and at a time when the operation of the ultrasonic transducer 32 is not affected. By supplying a control signal so as to operate, power is supplied to the ultrasonic transducer with a stable voltage, and the operation of the boosting means 43 is realized so as not to affect the entire flow measurement system by the influence of noise or the like. It becomes possible.
[0068]
Since the power supply control unit 44 can receive a measurement operation signal from the measurement control unit 41 as a signal, the booster unit 43 can be controlled more reliably without affecting the operation of the vibrator. It becomes like this.
[0069]
In FIG. 5, the power supply control means 44 and the measurement control means 41 are provided separately, but one logic means, for example, a microcomputer may be used as the same control means.
[0070]
Further, even if the power supply control means 44 instructs the boosting means 43 to open and close the inductance, the power supply control means 44 may not operate if the output voltage has not decreased so much.
[0071]
For example, when a DCDC converter is used as the booster 43, the output voltage may be monitored by the element itself.
[0072]
In such a case, it is possible to take a method of reliably operating the boosting operation after temporarily reducing the voltage by connecting an element that promotes power consumption such as a resistor to the output. Further, the output voltage of the boosting means 43 can be finely adjusted by shortening the operation time of the opening / closing means.
[0073]
The timing around the power supply at the start of operation will be described. Many control means use a method in which the power supply is frequently turned on when operating with power saving, the power supply is supplied to each unit only when the operation is really necessary, and the rest is performed otherwise. In a device that operates periodically, such as a flow rate measuring device, it is useful to shut off the power supply when not operating.
[0074]
For this reason, the operation of turning on the power frequently occurs, but various settings need to be made each time. If the operation of the boosting unit 43 is started before the supply voltage to the transmission unit 34 and the reception unit 35 is stabilized, there is a possibility that waste will occur in the time until the vibrator as a load operates after charging.
[0075]
Furthermore, if the voltage boosting unit 43 operates during the initial setting operation of the measurement control unit 41 or the like, there is a possibility that the system voltage fluctuates or that the measurement accuracy is degraded due to the generation of noise.
[0076]
For example, there is a case where a plurality of integrated circuits exist in the measurement control means 41 and initial data is exchanged and analog units are adjusted.
[0077]
In such a case, as shown in FIG. 6, the voltage of the input part of the power supply control means rises as shown in (a), and when the voltage exceeds the specified voltage, the digital device starts its operation as shown in (b). At time t1, the measurement control means 41 starts its operation and starts performing initial setting.
[0078]
Then, after the setting of each part is completed in the time up to t2, the power supply control means 44 sends a signal to operate the boosting means 43 after (c). The output of the booster 43 satisfies a predetermined voltage at the rising edge t3 as shown in (d).
[0079]
Thereafter, the measurement control unit 41 operates the transmission unit 34. By using such a stable boost control means, it is possible to realize accurate flow velocity and / or flow rate measurement that realizes stable operation of the measurement system.
[0080]
Furthermore, by operating the boosting unit 43 after setting the analog circuit or the like, it is possible to realize the operation of the boosting unit so that the influence of noise or the like is not given to the system.
[0081]
Further, another operation will be described with reference to FIG. When the power supply is frequently started up, if the voltage boosting unit 43 operates while the voltage rise from the power supply 42 is not stable, it may adversely affect peripheral operations or generate a wasteful operation waiting time. Therefore, as shown in FIG. 7A, when the voltage of the input unit of the power supply control unit rises and exceeds the specified voltage at t0, the digital device starts operation as shown in (b).
[0082]
Then, as shown in (c1), the power supply control means 44 sends a signal to operate the boosting means 43 at t1. Since the power supply output is almost stable between time t0 and t1, the operation of each part is settled.
[0083]
As described above, the power supply control means 44 operates the boosting means 43 after the power supply output is stabilized, so that the boosting means 43 can be operated after the output voltage of the power supply is stabilized and the circuit voltage of each part is determined and becomes a steady operation. It is possible to improve the stability of both the operation of the ultrasonic transducer as a load and the peripheral circuit.
[0084]
Further, another operation will be described with reference to FIG. Even if the power supply rises stably, the operation of other peripheral parts may not be stable yet. Therefore, similarly to the above operation, when the voltage of the input part of the power supply control unit rises as shown in FIG. 7A and exceeds the specified voltage at t0, the digital device starts operation as shown in FIG.
[0085]
Then, after a predetermined time T has elapsed from t0, the power supply control means 44 sends a signal to operate the boosting means 43 at t2 as shown in (c2). Since the operation and initial setting of the peripheral circuits are almost stable between the times t0 and t2, the operation of each part is also normal.
[0086]
Thus, instead of starting the operation immediately after the output voltage of the power supply is stabilized, it waits for a certain period of time, and after the circuit voltage of each part is determined and the initial operation is completed, the boosting unit is operated so that both the load operation and the peripheral circuit are operated. Stability can be improved.
[0087]
Further, another operation will be described with reference to FIG. After the start-up of the power supply is completed, when the booster 43 is operated by the power supply controller 44, the output of the booster 43 becomes higher than the voltage of the power supply 42.
[0088]
Then, when the voltage rises to a certain voltage, the device simply waits while consuming circuit current. When a power saving operation is performed, such an operation that requires a standby current must be avoided.
[0089]
Therefore, when the voltage of the input part of the power supply control means rises as shown in FIG. 8A and exceeds the specified voltage at t0, the digital device starts operation as shown in FIG. 8B. Thereafter, as shown in (c), the power supply control means 44 sends a signal to operate the boosting means 43 at t1.
[0090]
The output of the booster 43 rises as shown in (d), and after reaching a constant voltage at t2, the voltage is maintained. The power supply control means 44 issues a signal for stopping the operation of the boosting means 43 at t3 when a time longer than the time T1 from t1 to t2 has elapsed.
[0091]
As a result, the circuit current consumed in the booster 43 can be eliminated as much as possible. In this way, the power supply control means stops the operation of the boosting means when the output voltage of the boosting means reaches a predetermined value, thereby shortening the operation time of the boosting means, cutting wasteful power and shortening the noise generation time. Power saving operation becomes possible.
[0092]
(Example 2)
A second embodiment will be described with reference to FIGS. 9 and 10 as well. The difference from the first embodiment is that the operation of the boosting means is performed in the vicinity of the operation of the vibrator.
[0093]
First, as shown in the first embodiment, a load such as an ultrasonic transducer used in the flow rate measuring device operates to consume electric power, so that the output voltage of the boosting unit decreases.
[0094]
For example, when the first ultrasonic transducer 32 of FIG. 1 operates, the output voltage of the boosting unit 43 in FIG. 5 decreases. Therefore, the boosting unit 43 must operate to compensate for this.
[0095]
Therefore, the operation of the ultrasonic vibrator is stabilized by adjusting the timing at which the booster 43 is operated.
[0096]
When the first ultrasonic transducer 32 operates as shown in (a) at times t31, t33, t35, and t37 in FIG. 9, the power is consumed, and the output voltage of the booster 43 decreases.
[0097]
In order to prevent this, the power control means 44 operates the boosting means 43 to adjust the voltage at times t30, t32, t34, and t36 as shown in FIG.
[0098]
Although not shown before time t30, the output voltage of the booster 43 is lowered because the vibrator is operating, but the description is omitted because of the repeated operation. Since the operation of the vibrator serving as a load can be detected by the power control means 44 via the measurement control means 41, it is possible to adjust the voltage by sending a signal to the boosting means 43 before the vibrator operates. As a result, the output of the booster 43 shows a stable voltage state as shown in FIG.
[0099]
This is because the operation of the boosting means 43 is completed before the ultrasonic transducer operates, so that the voltage becomes an optimum value, and the high voltage can be supplied when the ultrasonic transducer as a load operates. It is possible to leave.
[0100]
Furthermore, since noise generation due to inductance operation or the like for the entire system is eliminated, stable measurement operation can be performed even when applied to flow measurement.
[0101]
In FIG. 9B, the operation of the boosting means 43 is stopped immediately before the ultrasonic transducer is operated. However, as shown in (b2), the operation is performed at a certain time ΔT2 before the ultrasonic transducer is operated. The power control means 44 may adjust so as to end the process.
[0102]
This may be the case where a weak voltage change (noise) occurs in the entire system due to a change in the stop signal from the power control means 44.
[0103]
If a signal is sent out before a certain time before the ultrasonic transducer operates so that the voltage change does not affect other means, for example, after the reflection or damping signal by the signal converges, Can be stably performed. Further, power saving can be realized by frequently turning on and off the boosting means.
[0104]
In this way, the power supply control means stops the operation of the boosting means before the operation of the transmission means is started, so that the operation of the boosting means can be terminated before the load operates, and when the load always operates, While maintaining the voltage supply state, the stability of the system is improved, and the operation time of the boosting means is shortened to enable the power saving operation.
[0105]
In FIG. 9, the boosting means always operates immediately before the vibrator operates. However, before the vibrator operates every fixed number of times or every number corresponding to the common divisor of the number of operations, the boosting means 43 is turned on. It may be configured to operate.
[0106]
Another operation will be described with reference to FIG. The operation of the ultrasonic transducer is stabilized by adjusting the timing at which the booster 43 is operated.
[0107]
When the first ultrasonic transducer 32 operates as shown in (a) at time t40, t42, t44, and t46 in FIG. Then, the power supply control means 44 operates the boosting means 43 to adjust the voltage.
[0108]
Since the operation of the ultrasonic vibrator as a load can be detected by the power control means 44 via the measurement control means 41, it is possible to adjust the voltage by sending a signal to the boosting means 43 after the operation of the ultrasonic vibrator. become.
[0109]
As a result, the output of the boosting means 43 shows a stable voltage state as shown in (c). This is to accurately grasp the voltage drop after the operation of the ultrasonic vibrator, replenish it with the boosting means 43, and perform the operation of the ultrasonic vibrator as a load next time after the boosted voltage is stabilized. Therefore, stable system operation can be performed when applied to flow velocity and / or flow rate measurement.
[0110]
For example, when a large capacitive load is connected to the booster 43, the voltage rise also changes with a large time constant, but when the voltage is adjusted after the operation of the ultrasonic transducer is completed, The voltage can be adjusted to a stable voltage with a margin long before the next ultrasonic transducer operates.
[0111]
In FIG. 10B, the operation of the boosting means 43 is stopped immediately after the operation of the ultrasonic transducer. However, as shown in FIG. 10B, the operation is performed at ΔT3 after a certain time after the operation of the ultrasonic transducer. The power control means 44 may adjust so as to start the operation.
[0112]
This is because a high voltage signal changes immediately after the ultrasonic transducer is operated, so that a voltage change including the ground may occur in the entire system.
[0113]
When the voltage change affects other means, for example, the power supply control means 44 may not be able to detect the accurate output voltage of the boosting means 43.
[0114]
Therefore, after the ultrasonic transducer is operated, after the electrical signal of the entire system is stabilized, the accurate voltage of the boosting means is grasped and then the boosting operation is performed, thereby enabling stable power management. Further, power saving can be realized by frequently turning on and off the boosting means.
[0115]
In this way, the power supply control means starts the operation of the boosting means after the operation of the transmission means is completed and prepares for the next operation of the ultrasonic vibrator, so that there is sufficient time before the operation of the ultrasonic vibrator. It is possible to supply a stable high voltage, improve the stability of the system, shorten the operation time of the boosting means, and enable a power saving operation.
[0116]
In this way, the power supply control means stops the operation of the boosting means after a lapse of a certain time after the operation of the transmission means, so that the transmission operation can be performed at a stable voltage, and then the operation is stopped after sufficient boosting operation is performed. By doing so, it becomes possible to prepare for the next operation.
[0117]
In FIG. 10, the boosting unit always operates after the ultrasonic transducer is operated. However, the boosting unit is operated after the ultrasonic transducer is operated every certain number of times or every number corresponding to the common divisor of the number of operations. It is also possible to take a configuration that operates.
[0118]
(Example 3)
A flow rate measuring apparatus according to the third embodiment will be described.
[0119]
The difference from the first embodiment is that a storage medium 46 having a program for causing a computer to function to ensure the operation of the power supply control means 44 for adjusting the operation of the boosting means 43 is used.
[0120]
1 and 5, in order to perform the operation of the power supply control means 44 shown in the first to second embodiments, the output change, secular change, temperature change, Correlation such as the operation timing of the boosting means is obtained with respect to the stability of the system, and determination software for determining the degree of fitness such as a membership function of fuzzy control, for example, is stored in the storage medium 46 as a program.
[0121]
Usually, it is convenient to use an electrically writable memory such as a microcomputer memory or a flash memory.
[0122]
As described above, when the operation of the power supply control unit 44 can be performed by a program, the operation of the boosting unit 43 that follows the change in the driving voltage of the ultrasonic transducer is performed by software. As a result, it is possible to easily set and change the conditions for the number of transmissions, set and change the voltage adjustment conditions before and after the operation of the switching means 36, and flexibly cope with aging, etc., so that the accuracy of the measurement time can be improved more flexibly. .
[0123]
In the present embodiment, operations other than the power control means 44 may be performed by a program using a microcomputer or the like.
[0124]
【The invention's effect】
As is apparent from the above description, according to the measuring apparatus of the present invention, the power supply control means frequently controls the voltage raising operation by the boosting means according to the operation of the entire circuit and the operation of the load. The power supply is supplied to the load with a stable voltage by ensuring the stable power supply voltage and controlling the voltage according to the operation of the load. Operation can be realized. By using such a stable boosting means, it is possible to realize a highly accurate flow velocity and / or flow rate measurement that realizes a stable operation of the measurement system.
[Brief description of the drawings]
FIG. 1 is an overall block diagram of a flow measuring apparatus according to the present invention.
FIG. 2A is a timing chart showing the operation of measurement control means in the measurement apparatus.
(B) Timing chart showing operation of transmission wave in the measurement apparatus
(C) Timing chart showing operation of received wave in the measurement apparatus
(D) Timing chart showing operation of delay means in the measurement apparatus
FIG. 3 is a block diagram around a power source in the first embodiment of the present invention.
FIG. 4A is a timing chart showing the operation of a load in a conventional booster circuit.
(B) Timing chart showing output in conventional booster circuit
(C) Timing chart showing the operation of the boosting means in the measuring apparatus of the present invention.
(D) Timing chart showing the operation of the power supply control means
(E) Timing chart showing the operation of the boosting means
FIG. 5 is a block diagram showing connections around the transmission means of the flow measuring device
FIG. 6A is a timing chart showing the operation of a power supply in the measurement apparatus.
(B) Timing chart showing operation of measurement control means in the measurement apparatus
(C) Timing chart showing operation of power control means in the measurement apparatus
(D) Timing chart showing the operation of the boosting means in the measurement apparatus
FIG. 7A is a timing chart showing the operation of the power supply in the measurement apparatus.
(B) Timing chart showing operation of measurement control means in the measurement apparatus
(C1) Timing chart showing the operation of the power supply control means in the measurement apparatus
(C2) Timing chart showing the operation of the power supply control means in the measurement apparatus
FIG. 8A is a timing chart showing the operation of a power supply in the measurement apparatus.
(B) Timing chart showing operation of measurement control means in the same amount measuring apparatus
(C) Timing chart showing operation of power control means in the measurement apparatus
(D) Timing chart showing the operation of the boosting means in the measurement apparatus
FIG. 9A is a timing chart showing the operation of the ultrasonic transducer in the measuring apparatus according to the second embodiment of the present invention.
(B) Timing chart showing operation of power supply control means in the measurement apparatus
(B2) Timing chart showing the operation of the power supply control means in the measurement apparatus
(C) Timing chart showing the operation of the boosting means in the measuring device
FIG. 10A is a timing chart showing the operation of the vibrator in the measurement apparatus.
(B) Timing chart showing operation of power supply control means in the measurement apparatus
(B2) Timing chart showing the operation of the power supply control means in the measurement apparatus
(C) Timing chart showing the operation of the boosting means in the measuring device
FIG. 11 is an overall block diagram of a conventional booster circuit.
FIG. 12 is an overall block diagram of a conventional flow rate measuring device.
[Explanation of symbols]
31 channel
32 First ultrasonic transducer
33 Second ultrasonic transducer
34 Transmission means
35 Receiving means
36 switching means
37 Repeating means
38 Delay means
39 Timekeeping
40 Calculation means
42 Power supply
43 Boosting means
44 Power control means

Claims (7)

A pair of ultrasonic transducers that are arranged in the flow path of the fluid to be measured and transmit / receive ultrasonic waves, a transmission unit that drives these ultrasonic transducers, and an output signal of the reception-side ultrasonic transducer are converted into electrical signals A receiving unit, a switching unit for transmission / reception of the ultrasonic transducer, a repeating unit for performing ultrasonic propagation between the ultrasonic transducers a plurality of times, and a delay for delaying a transmission signal from the ultrasonic transducer during the repetition Means, time measuring means for measuring a plurality of times of propagation times, calculation means for calculating a flow velocity and / or a flow rate based on a difference between the time measured values by the time measuring means, a power source, and a higher voltage than the power source. A fluid flow measuring device, comprising: a pressure-increasing means for generating a power source; and a power source control means for controlling the power source and the pressure-increasing means. 2. The fluid flow measuring device according to claim 1, wherein the power control means operates the boosting means after the power output is stabilized. 2. The fluid flow measuring device according to claim 1, wherein the power supply control means operates the boosting means after a predetermined time elapses in the power supply output. 2. The fluid flow measuring device according to claim 1, wherein the power supply control means stops the operation of the boosting means when the output voltage of the boosting means reaches a predetermined value. 2. The fluid flow measuring device according to claim 1, wherein the power supply control means stops the operation of the boosting means before the operation of the transmission means is started. 2. The fluid flow measuring device according to claim 1, wherein the power supply control means stops the operation of the boosting means after a lapse of a certain time after the operation of the transmission means is completed. The program for functioning a computer as a power supply control means in any one of Claims 1-6.

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