WO2017181939A1

WO2017181939A1 - Method of calibrating ultrasound transmission time for ultrasound flowmeter, system, and flowmeter

Info

Publication number: WO2017181939A1
Application number: PCT/CN2017/080919
Authority: WO
Inventors: 刘勋
Original assignee: 成都千嘉科技有限公司
Priority date: 2016-04-20
Filing date: 2017-04-18
Publication date: 2017-10-26
Also published as: CN105716674A; CN105716674B; AU2017254028B2; AU2017254028A1

Abstract

A method of calibrating ultrasound transmission time for an ultrasound flowmeter, a system, and a flowmeter. The method comprises: determining, by gradually increasing or decreasing a number of ultrasonic pulses in each transmission, that which of the ultrasonic pulses in each transmission is the first ultrasonic pulse received in an actual measurement, thereby determining an actual transmission time of a valid ultrasonic pulse, preventing a measurement error as a result of taking a transmission time of the first ultrasonic pulse transmitted by an ultrasonic transducer as a start time of a measurement as disclosed in the prior art.

Description

Ultrasonic flowmeter ultrasonic transmission time correction method, system and flowmeter

Technical field

The invention relates to the field of gas metering, in particular to a method, a system and a flow meter for correcting ultrasonic transmission time of an ultrasonic flowmeter.

Background technique

The basic working principle of the existing ultrasonic flowmeter is to set two ultrasonic transducers, and determine the flow rate of the gas by measuring the propagation time of the ultrasonic waves in the flowing gas, and then calculate the flow rate of the gas; but in practical applications, As shown in Fig. 5, the amplitude of the ultrasonic pulse emitted by the ultrasonic transducer at the initial stage after each start is gradually changed from small to large until stable; in the ultrasonic flowmeter, the initial amplitude of the ultrasonic wave is smaller. Since the energy is small, it cannot be smoothly propagated to another ultrasonic transducer and cannot be recorded, which results in the system not being able to record the initial time of the transducer transmitting the ultrasonic wave, but due to the initial transmission of several small energies The ultrasonic wave is not received, and the system cannot judge that the first valid ultrasonic wave received is the first pulse sent by the transducer (different gas components, different working environments will cause the first one to be received. The pulse is different), which causes the system to be unable to determine the transmission time of the first valid ultrasonic wave received, and thus Entire measurement errors.

Summary of the invention

The object of the present invention is to overcome the problem that the small ultrasonic wave transmitted in the initial stage of the ultrasonic transducer can not be received in the ultrasonic flowmeter, and the system cannot judge that the first ultrasonic wave received is the transducer transmission. The first few waves result in the inability to determine the transmission time of the first effective ultrasonic wave, providing a means for determining that the first effective ultrasonic wave received is the first wave transmitted by the transducer, thereby determining the actual effective ultrasonic wave The ultrasonic transmission start time correction method of the initial transmission time, in order to achieve the above object of the invention, the present invention provides the following technical solutions:

An ultrasonic transmission time correction method for an ultrasonic flowmeter, which sets a value of a transmission pulse N, and an initial value of N is a natural number below 4, and the correction includes the following steps:

(1-1) the ultrasonic transducer transmits N ultrasonic pulses; determines whether ultrasonic waves are received; if no ultrasonic waves are received, proceeds to step (1-2);

(1-2) N value plus one, send N ultrasonic pulses according to the corrected N value; determine whether there is ultrasonic wave received, if not, repeat this step until ultrasonic waves are received, at this time, the current value of N The first ultrasonic pulse that can be received, that is, the Nth ultrasonic pulse is the first ultrasonic pulse that can be received; then in the normal ultrasonic gas measurement, we know that in one measurement process , the Nth (the N is the result value obtained by the method), the transmission time of the ultrasonic pulse is the real measurement start time, and the first N-1 ultrasonic waves are actually due to the energy Too small is not received.

The invention also provides another ultrasonic transmission time correction method for the ultrasonic flowmeter, which sets a transmission pulse value N, and the initial value of N is 6 or more natural numbers, and the correction includes the following steps:

(2-1) the ultrasonic transducer transmits N ultrasonic pulses; determines whether ultrasonic waves are received; if any ultrasonic waves are received, proceeds to step (2-2);

(2-2) The value of N is decremented by one, and N ultrasonic pulses are transmitted according to the corrected value of N; it is judged whether or not ultrasonic waves are received, and if so, this step is repeated until no ultrasonic waves are received; The current value plus one) ultrasonic pulse is the first ultrasonic pulse that can be received.

The invention also provides another ultrasonic transmission time correction method for the ultrasonic flowmeter, which sets an initial value of a transmission pulse value N, N to an arbitrary natural number, and the correction comprises the following steps:

(3-1) the ultrasonic transducer transmits N ultrasonic pulses; determines whether ultrasonic waves are received; if no ultrasonic waves are received, the process proceeds to step (3-2), and if received, proceeds to step (3-3);

(3-2) The N value is incremented by one, and N ultrasonic pulses are transmitted according to the corrected N value; it is judged whether or not the ultrasonic wave is received, and if not, the step is repeated until the ultrasonic wave is received, and the Nth ultrasonic pulse is received. Is the first ultrasonic pulse that can be received;

(3-3) The value of N is decremented by one, and N ultrasonic pulses are transmitted according to the corrected value of N; it is judged whether or not ultrasonic waves are received, and if so, this step is repeated until no ultrasonic waves are received; One ultrasonic pulse is the first ultrasonic pulse that can be received.

Further, an ultrasonic amplitude threshold M is set, and only the amplitude of the received ultrasonic wave exceeds the ultrasonic amplitude threshold M to be recognized as receiving the ultrasonic wave (which may also be referred to as an effective ultrasonic wave).

The invention also provides an ultrasonic flowmeter ultrasonic transmission time correction system, which comprises a pulse pulse value setting module, a transmission control module and a receiving judgment module;

The sending pulse value setting module is configured with a sending pulse value N, and the initial value of N is a natural number;

The sending control module is connected to the first ultrasonic transducer, and is configured to control the first ultrasonic transducer to send N ultrasonic pulses according to an N value;

The receiving judging module is connected to the second ultrasonic transducer, and configured to determine whether the second ultrasonic transducer receives the ultrasonic wave, and according to the determination result, the sending period setting module increases the value of the sending pulse by one or minus one. .

For example, after the first ultrasonic transducer transmits the ultrasonic pulse, for example, the second ultrasonic transducer does not receive the ultrasonic wave, the transmitting pulse value setting module increases the value of N by one, and the transmitting control module controls the first An ultrasonic transducer transmits N ultrasonic pulses according to the corrected N value; if the second ultrasonic transducer still does not receive the super Acoustic wave, the transmission cycle setting module increases the value of N again, and so on, until the second ultrasonic transducer can receive the ultrasonic wave, then the current value of N is the first ultrasonic pulse that can be received. That is, the Nth ultrasonic pulse is the first ultrasonic pulse that can be received.

For example, after the first ultrasonic transducer transmits the ultrasonic wave, the second ultrasonic transducer can receive the ultrasonic wave, the sending cycle setting module decrements the value of N by one, and the transmitting control module controls the first ultrasonic transducer. Sending N ultrasonic pulses according to the corrected N value; if the second ultrasonic transducer is still capable of receiving ultrasonic waves, the transmission cycle setting module reduces the N value by one again, and so on, until the second ultrasonic transducer is switched The ultrasonic wave cannot be received, and the current value of N is added to the first received ultrasonic period.

Further, the method further includes an amplitude threshold setting module, wherein the amplitude threshold setting module is configured with an ultrasonic amplitude threshold M, and only when the ultrasonic amplitude received by the second ultrasonic transducer exceeds the threshold M It was determined that the ultrasonic wave was received (or that an effective ultrasonic wave was received).

The invention also provides an ultrasonic flowmeter comprising an ultrasonic flowmeter ultrasonic transmission time correction system as described above.

Compared with the prior art, the beneficial effects of the present invention: the ultrasonic transmission time correction method of the ultrasonic flowmeter provided by the present invention determines the first one in the actual measurement by sequentially increasing or decreasing the number of ultrasonic pulses per shot. The received ultrasonic pulse is the first ultrasonic pulse transmitted by the ultrasonic transducer, thereby determining the actual transmission time of the effective ultrasonic pulse, thereby avoiding the prior art, because the ultrasonic transducer transmits the first ultrasonic pulse. The transmission time is the measurement error caused by the start time of the measurement.

BRIEF DESCRIPTION OF THE DRAWINGS:

FIG. 1 is a flowchart of a transmission time correction method provided by the present invention.

2 is a flow chart of another embodiment of a transmission time correction method provided by the present invention.

FIG. 3 is a flowchart of still another embodiment of a transmission time correction method provided by the present invention.

4 is a schematic block diagram of a transmission time correction system provided by the present invention.

Figure 5 is a schematic diagram of the ultrasonic transducer transmitting ultrasonic pulse amplitude from start to steady.

Figure 6 is a typical pulse change trend diagram sent or received when the ultrasonic transducer is normally measured.

detailed description

The present invention will be further described in detail below with reference to the drawings and specific embodiments. However, the scope of the above-mentioned subject matter of the present invention should not be construed as being limited to the following embodiments, and the technology implemented based on the present invention is within the scope of the present invention.

Embodiment 1: As shown in FIG. 1 , this embodiment provides an ultrasonic transmission time correction method for an ultrasonic flowmeter. The method sets a value of a transmission pulse N, and the initial value of N is a natural number of 4 or less. In this embodiment, the initial value of the N is set to 1 (since usually the first pulse is not received, therefore The initial value can also be directly set to 2, 3, 4 or even 5 smaller natural numbers); the correction includes the following steps:

S101: the ultrasonic transducer transmits one ultrasonic pulse; determines whether the ultrasonic wave is received; if not received, proceeds to step S102;

S102: adding N values (ie, N=N+1), sending N ultrasonic pulses according to the corrected N value; determining whether ultrasonic waves are received, if not, repeating this step until ultrasonic waves are received, The current value of N is the first ultrasonic pulse that can be received, that is, the Nth ultrasonic pulse is the first ultrasonic pulse that can be received; then, in the normal ultrasonic gas measurement, we know that In the course of one measurement, the Nth (the N is the result value obtained by the method), the transmission time of the ultrasonic pulse is the real measurement start time, and the first N-1 ultrasonic waves are not received because the energy is too small. To.

When the ultrasonic gas flowmeter is applied by the method provided in this embodiment, after the flowmeter is installed and the gas is normally flowed, the ultrasonic transducer is first controlled to send one pulse of ultrasonic waves. Generally, the ultrasonic transducer is sent at the initial state. The ultrasonic pulse amplitude is small, and the gas pulse is not blocked by another ultrasonic transducer; at this time, the ultrasonic transducer transmits two pulses of ultrasonic waves, and the detection can be received. And so on, until another ultrasonic transducer can receive the pulse, assuming that when the ultrasonic transducer transmits only one pulse, it cannot be received, and similarly, only two pulses can not be received. It is also assumed that when the ultrasonic transducer transmits three pulses at a time, the other ultrasonic transducer receives the pulse signal smoothly, then we can determine that each ultrasonic transducer is sent in the current gas composition and the current working environment. The first two pulses cannot be received, so in the subsequent measurement process, as shown in Figure 5, we think Start time of ultrasonic measurement times is not an ultrasonic transducer transmits ultrasonic waves start time T0, but the third ultrasonic transducer transmits ultrasonic pulse time T1.

Further, an ultrasonic amplitude threshold M is set, and only the amplitude of the received ultrasonic wave exceeds the ultrasonic amplitude threshold M to be recognized as receiving the ultrasonic wave (which may also be referred to as an effective ultrasonic wave). This is because, in some cases, the amplitude of the first received ultrasonic pulse is still small (eg, pulse 3 in Figure 5), that is, although it can be received, due to its small energy, It may be more susceptible to noise interference, which may cause errors in measurement calculations. Therefore, we usually set an ultrasonic amplitude threshold M. Only when the amplitude of the received ultrasonic pulse exceeds M, we identify it as an effective ultrasonic wave. As shown in Fig. 5, although it is possible that the pulse 3 can be received, since its amplitude is smaller than the threshold M, we throw it away, but think that it is a valid pulse from the pulse 4 whose amplitude exceeds the threshold M, that is, We believe that the time T2 at which the ultrasonic transducer transmits the fourth ultrasonic pulse is the start time of the measurement.

In fact, in the normal measurement, the ultrasonic transducer does not transmit a long and infinite number of pulse waves without limitation, but transmits a pulse wave of a specified number (such as 11 pulse waves in FIG. 6) as shown in FIG. At the receiving end, only a part of it may be received (for example, only pulse 3 to pulse 9 in Fig. 6 can be received), and in order to remove the interference, after setting the threshold M, we only select the amplitude above the threshold. The pulse of M is used (pulse 4 to pulse 9 in Fig. 6) to ensure the accuracy of the measurement to the utmost.

Embodiment 2: As shown in FIG. 2, this embodiment provides another ultrasonic transmission time correction method for an ultrasonic flowmeter, and sets an initial value of a transmission pulse N, N to a natural number of 6 or more, if the value can be set The larger natural numbers are 6, 9, 12 or even 15; the correction consists of the following steps:

S201: the ultrasonic transducer transmits N ultrasonic pulses; determines whether the ultrasonic wave is received; if the ultrasonic wave is received, proceeds to step S202;

S202: The N value is decreased by one, and N ultrasonic pulses are sent according to the corrected N value; determining whether there is ultrasonic wave received, if any, repeating this step until no ultrasonic wave is received; then (N current value of N Add one) ultrasonic pulse to the first ultrasonic pulse that can be received.

Embodiment 3: As shown in FIG. 3, in this embodiment, we arbitrarily set a value N of a transmission pulse, and the correction includes the following steps:

S301: the ultrasonic transducer sends N ultrasonic pulses; determine whether there is no ultrasonic wave received; if no ultrasonic wave is received, then proceeds to step S302, if received, proceeds to step S303;

S302: The N value is increased by one, and the N ultrasonic pulses are sent according to the corrected N value; determining whether the ultrasonic wave is received, if not, repeating the step until the ultrasonic wave is received, the Nth ultrasonic pulse is the first An ultrasonic pulse that can be received;

S303: The N value is decreased by one, and N ultrasonic pulses are transmitted according to the corrected N value; determining whether there is ultrasonic wave received, if any, repeating this step until no ultrasonic wave is received; then the N+1th ultrasonic wave The pulse is the first ultrasonic pulse that can be received.

Embodiments: 4: As shown in FIG. 4, this embodiment provides an ultrasonic flowmeter ultrasonic transmission time correction system, including a transmission pulse value setting module 100, a transmission control module 200, and a reception determination module 300;

The sending pulse value setting module 100 is configured with a sending pulse value N, and the initial value of N is a natural number;

The sending control module 200 is connected to the first ultrasonic transducer, and is configured to control the first ultrasonic transducer to send N ultrasonic pulses according to an N value;

The receiving judging module 300 is connected to the second ultrasonic transducer, and is configured to determine whether the second ultrasonic transducer receives the ultrasonic wave, and control the sending period setting module to increase or decrease the sending pulse value according to the determination result. One.

For example, after the first ultrasonic transducer transmits the ultrasonic pulse, for example, the second ultrasonic transducer does not receive the ultrasonic wave, the transmitting pulse value setting module 100 increases the value of N by one, and the transmitting control module 200 Controlling the first ultrasonic transducer to transmit N ultrasonic pulses according to the corrected N value; if the second ultrasonic transducer still does not receive the ultrasonic wave, the transmission cycle setting module increases the N value by one again, and thus cycles. Until the second ultrasonic transducer can receive the ultrasonic wave, then the current value of N is the first ultrasonic pulse that can be received, that is, the Nth ultrasonic pulse is the first ultrasonic pulse that can be received. .

For example, after the first ultrasonic transducer transmits the ultrasonic wave, the second ultrasonic transducer can receive the ultrasonic wave, the transmission cycle setting module decrements the value of N by one, and the transmission control module 200 controls the first ultrasonic transducer. Transmitting N ultrasonic pulses according to the corrected N value; if the second ultrasonic transducer is still capable of receiving ultrasonic waves, the transmission cycle setting module reduces the N value by one again, and so on, until the second ultrasonic wave is switched The energy sensor cannot receive the ultrasonic wave, and the current value of N is added to the first received ultrasonic wave period.

Further, the method further includes an amplitude threshold setting module, wherein the amplitude threshold setting module is configured with an ultrasonic amplitude threshold M, and only when the ultrasonic amplitude received by the second ultrasonic transducer exceeds the threshold M It is determined that the ultrasonic wave is received (or an effective ultrasonic wave is received), and the threshold value M can generally be set such that the amplitude of the ultrasonic pulse transmitted by the ultrasonic transducer is stable (such as pulse 5 to pulse 10 in FIG. 5). 70%-90%.

Embodiment 5: This embodiment provides an ultrasonic flowmeter comprising an ultrasonic flowmeter ultrasonic transmission time correction system as provided in Embodiment 4.

Claims

An ultrasonic transmission time correction method for an ultrasonic flowmeter, characterized in that a value of a transmission pulse is set, and an initial value of N is a natural number below 4, and the correction includes the following steps:

(1-1) the ultrasonic transducer transmits N ultrasonic pulses; determines whether ultrasonic waves are received; if no ultrasonic waves are received, proceeds to step (1-2);

(1-2) N value plus one, send N ultrasonic pulses according to the corrected N value; determine whether there is ultrasonic wave received, if not, repeat this step until ultrasonic waves are received, then the Nth ultrasonic pulse It is the first ultrasonic pulse that can be received.
An ultrasonic transmission time correction method for an ultrasonic flowmeter, characterized in that a value of a transmission pulse is set N, and an initial value of N is a natural number of 6 or more, and the correction includes the following steps:

(2-1) the ultrasonic transducer transmits N ultrasonic pulses; determines whether ultrasonic waves are received; if any ultrasonic waves are received, proceeds to step (2-2);

(2-2) The N value is decremented by one, and N ultrasonic pulses are transmitted according to the corrected N value; it is judged whether or not the ultrasonic wave is received, and if so, the step is repeated until no ultrasonic wave is received; One ultrasonic pulse is the first ultrasonic pulse that can be received.
An ultrasonic transmission time correction method for an ultrasonic flowmeter, characterized in that an initial value of a transmission pulse value N, N is set to an arbitrary natural number, and the correction comprises the following steps:

(3-1) the ultrasonic transducer transmits N ultrasonic pulses; determines whether ultrasonic waves are received; if no ultrasonic waves are received, the process proceeds to step (3-2), and if received, proceeds to step (3-3);

(3-2) The N value is incremented by one, and N ultrasonic pulses are transmitted according to the corrected N value; it is judged whether or not the ultrasonic wave is received, and if not, the step is repeated until the ultrasonic wave is received, and the Nth ultrasonic pulse is received. Is the first ultrasonic pulse that can be received;

(3-3) The value of N is decremented by one, and N ultrasonic pulses are transmitted according to the corrected value of N; it is judged whether or not ultrasonic waves are received, and if so, this step is repeated until no ultrasonic waves are received; One ultrasonic pulse is the first ultrasonic pulse that can be received.
The ultrasonic transmission time correction method according to any one of claims 1 to 3, characterized in that an ultrasonic amplitude threshold M is further set, and only the amplitude of the received ultrasonic pulse exceeds the ultrasonic amplitude threshold M is recognized. In order to receive the ultrasound.
An ultrasonic flowmeter ultrasonic transmission time correction system, comprising: a transmission pulse value setting module, a transmission control module, and a receiving judgment module;

The sending pulse value setting module is configured with a sending pulse value N, and the initial value of N is a natural number;

The sending control module is connected to the first ultrasonic transducer, and is configured to control the first ultrasonic transducer to send N ultrasonic pulses according to an N value;

The receiving judging module is connected to the second ultrasonic transducer, and configured to determine whether the second ultrasonic transducer receives the ultrasonic wave, and according to the determination result, the sending period setting module increases the value of the sending pulse by one or minus one. .
The ultrasonic transmission time correction system according to claim 5, further comprising an amplitude threshold setting module, wherein the amplitude threshold setting module is configured with an ultrasonic amplitude threshold M, when the second ultrasonic transducer When the received ultrasonic wave amplitude exceeds the threshold value M, it is determined that the ultrasonic wave has been received.
An ultrasonic flowmeter characterized by comprising an ultrasonic flowmeter ultrasonic transmission time correction system according to claim 5 or 6.