CN116067461A - Ultrasonic transducer detection method based on TDC chip - Google Patents

Abstract

The invention relates to the technical field of ultrasonic transducer detection methods, in particular to an ultrasonic transducer detection method based on a TDC chip. The technical scheme of the invention is as follows: the TDC chip is respectively connected with the transducer to be tested and the standard transducer in a communication way to form a loop; initializing a head wave threshold of the TDC chip; the TDC chip sends an excitation signal to a transducer to be tested or a standard transducer; the TDC chip receives echo signals returned by the standard transducer or the transducer to be tested; calculating the amplitude A of a sine wave with the first amplitude exceeding a first wave threshold value in echo signals received by the TDC chip; increasing the head wave threshold of the TDC chip until the TDC chip overtime; and for the amplitudes with the same or similar values in the calculated amplitudes, only one of the amplitudes is reserved, and the number of the rest amplitudes is recorded so as to reflect the starting rate of the transducer to be measured. The detection mode uses fewer tools, the detection process is simpler, the detection cost is lower, and the detection efficiency is higher.

Description

Ultrasonic transducer detection method based on TDC chip

Technical Field

The invention relates to a detection method of an ultrasonic transducer, in particular to a detection method of an ultrasonic transducer based on a TDC chip.

Background

In the ultrasonic water meter industry, the transducer is a ring playing a decisive role, is the basis of ultrasonic measurement and determines the accuracy of measurement.

At present, the detection of an ultrasonic transducer mainly depends on the detection of a transducer manufacturer before the product leaves the factory. Thus, the quality of the ultrasonic water meter product depends largely on the detection of the transducer by the transducer manufacturer, and for the ultrasonic water meter manufacturer, the quality of the product cannot be completely controlled by the ultrasonic water meter manufacturer. However, if the ultrasonic water meter manufacturer detects the transducer, the cost of the detection is high, a plurality of tools such as a corresponding oscilloscope, a spectrometer and a universal meter are needed, the time cost is high, the labor and time cost is high, the detection is not suitable for the ultrasonic water meter enterprise to fully detect the transducer, and the operation of the upstream industry is easy to repeat. Thus, there is a need in the industry for a low cost transducer detection method.

Disclosure of Invention

The invention aims to solve the problems and provide an ultrasonic transducer detection method based on a TDC chip.

In order to achieve the above purpose, the present invention is realized by the following technical scheme:

an ultrasonic transducer detection method based on a TDC chip comprises the following steps:

s100, connecting the TDC chip with a transducer to be tested and a standard transducer in a communication way to form a loop;

s102, initializing a head wave threshold of a TDC chip;

s104, the TDC chip sends an excitation signal to the transducer to be tested or the standard transducer;

s106, the TDC chip receives echo signals returned by the standard transducer or the transducer to be tested;

s108, calculating the amplitude A of a sine wave with the first amplitude exceeding a head wave threshold value in the echo signals received by the TDC chip by using the following formula;

wherein A is amplitude, wave_set is a first wave threshold, wwave_set is a pulse width corresponding to the first wave threshold, and W0 is a standard half-wave pulse width of an echo signal received by the TDC chip;

s110, increasing the head wave threshold of the TDC chip, and executing the step S104 until the TDC chip is overtime;

and S112, for the amplitudes with the same or similar values in the calculated amplitudes, only one of the amplitudes is reserved, and the number of the rest amplitudes is recorded so as to reflect the vibration starting rate of the transducer to be tested.

Preferably, the method further comprises:

s114, recording the arrival time of each sine wave in echo signals received by the TDC chip, calculating the time difference of arrival time of two adjacent sine waves from the sine wave with the first amplitude exceeding the threshold value of the first wave, and judging that the working frequency of the transducer to be tested meets the standard if the values of the time differences are equal.

Preferably, the method further comprises:

s116, taking the amplitude with the largest value in the rest amplitude values in the step S112 as the largest amplitude value of the oscillation of the transducer to be tested.

Preferably, in the step S110, the increase amount of the threshold value of the head wave is 1-5mv.

The invention has the beneficial effects that:

1. according to the invention, the amplitude A of the sine wave with the first amplitude exceeding the threshold value of the first wave in the echo signal received by the TDC chip is calculated by utilizing the trigonometric function principle, and a plurality of different amplitudes A can be obtained by continuously changing the threshold value of the first wave of the TDC chip until the TDC chip overtime is generated, only one of the amplitudes with the same or similar values in the calculated amplitudes is reserved, the number of the remaining amplitudes is recorded, the number of the remaining amplitudes can reflect the oscillation starting rate of the transducer to be measured, and the amplitude with the largest value in the remaining amplitudes is the maximum amplitude of the transducer to be measured. Compared with the prior art, the detection method has the advantages of fewer tools, simpler detection process, lower detection cost and higher detection efficiency.

2. The scheme has stronger pertinence, is suitable for ultrasonic water meter manufacturers adopting the TDC chip, is very in line with the metering waveform principle of the TDC chip, can display the amplitude of the waveform through an upper computer, and has the important parameters such as the number of the amplitude (the same or similar amplitude in the obtained amplitude and only one amplitude reserved) in the overtime process of the TDC chip, the time difference of arrival time of two adjacent sine waves and the like, thereby helping to analyze the data artificially.

Drawings

Fig. 1 is a schematic diagram of a TDC chip and its peripheral circuit.

FIG. 2 is a flow chart of the detection method of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the following description will be made in detail with reference to the technical solutions in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by a person skilled in the art without any inventive effort, are intended to be within the scope of the present invention, based on the embodiments of the present invention.

The method mainly utilizes the principle of trigonometric function, restores sine wave through the formula of Asin (x), and uses the TDC chip to set the head wave threshold value (wave_set) of the TDC chip to restore the peak of the sine wave where the head wave threshold value is located: assuming that the threshold of the head wave of the TDC chip is 10mv, the half-wavelength ratio obtained is 0.4 (that is, the ratio of the pulse width corresponding to the current threshold of the head wave to the standard half-wave pulse width is 0.4), and then the method is carried out by the formula

And calculating an x value to obtain the position of the head wave threshold of the TDC chip at the current wave, and calculating the amplitude A to be 12mv through a formula Asin (54 °) =10mv.

By using this principle, a plurality of a values can be obtained by continuously changing the head wave threshold of the TDC chip, and the transducer oscillation must reach the peak of an amplitude value under the condition that the number of excitations of the TDC chip (square waves sent by the TDC chip) is sufficient according to the characteristics of the transducer. It will be appreciated that when the transducer (now the receiving transducer) receives a first wave, it produces an oscillation of X intensity, and when the second wave is received, the oscillation of the first wave has not yet ended, and the first wave and the second wave can be superimposed, i.e. of 2X intensity, because of the phase coincidence, but the maximum intensity at which the transducer can oscillate in total is only Y, i.e. nX > Y (n being the nth wave received by the transducer), the transducer can only exhibit Y oscillations. Therefore, the last amplitude value must be Y, and when the head wave threshold value of the TDC chip is greater than the Y value, the amplitude value of the signal cannot be read, so that the condition that the TDC chip is overtime is generated.

As shown in fig. 2, the method for detecting an ultrasonic transducer based on a TDC chip according to the present embodiment includes:

s100, connecting the TDC chip with a transducer to be tested and a standard transducer in a communication way to form a loop; specifically, in this example, the TDC chip uses an ultrasonic flow measurement chip with the model MS1030, and connects the pin UP in fig. 1 with the signal line (usually the red line) of the standard transducer, and the pin AGND with the ground line (usually the white line) of the standard transducer; pin DOWN in fig. 1 is connected to a signal line (typically a red line) of the transducer under test, and pin AGND is connected to a ground line (typically a white line) of the transducer under test;

s102, initializing a head wave threshold of a TDC chip;

s104, the TDC chip sends an excitation signal to the standard transducer; the standard transducer is used as a transmitting transducer, generates vibration after receiving an excitation signal, and radiates sound waves into a medium; the transducer to be measured is used as a receiving transducer, and sound waves in a medium act on the transducer to be measured, so that a mechanical vibration system of the transducer to be measured vibrates, an electric field or a magnetic field in an energy storage element of the transducer to be measured is caused to correspondingly change, and an electric output end of the transducer to be measured generates an echo signal corresponding to an acoustic signal;

s106, the TDC chip receives an echo signal returned by the transducer to be tested;

s108, calculating the amplitude A of a sine wave with the first amplitude exceeding a head wave threshold value in the echo signals received by the TDC chip by using the following formula;

wherein A is amplitude; wave_set is the first wave threshold; wwave_set is the pulse width corresponding to the initial wave threshold value, and can be directly read from a register of the TDC chip (the TDC chip records the time of the rising edge and the time of the falling edge when the echo signal/sine wave corresponds to the initial wave threshold value, and the difference between the two times is stored in the register and used as the pulse width corresponding to the initial wave threshold value); w0 is a standard half-wave pulse width of an echo signal received by the TDC chip, the standard half-wave pulse width is related to the oscillation frequency of a standard transducer or a transducer to be tested, and if the oscillation frequency of the standard transducer or the transducer to be tested is 1 MHz, the standard half-wave pulse width is 0.5 microsecond;

s110, increasing the head wave threshold of the TDC chip, and executing the step S104 until the TDC chip is overtime; the increase of the head wave threshold value is 1-5mv;

s112, for the amplitudes with the same or similar values in the calculated amplitudes, only one of the amplitudes is reserved, the number of the rest amplitudes is recorded, the number of the rest amplitudes can reflect the starting rate of the transducer to be measured (the more the number of the rest amplitudes is, the slower the starting rate is, otherwise, the faster the starting rate is represented), and the amplitude with the largest value in the rest amplitudes is the maximum amplitude of the transducer to be measured capable of oscillating. Compared with the prior art, the detection method has the advantages of fewer tools, simpler detection process, lower detection cost and higher detection efficiency. Normally, if the number of the remaining amplitude values is less than or equal to 3, judging that the starting rate of the transducer to be tested meets the requirement; and if the amplitude with the largest value in the rest amplitudes is in the range of 130-250mv, judging that the maximum amplitude of the transducer to be tested, which can oscillate, meets the requirement.

For the same or similar magnitudes as the values described above, the difference is typically no more than 5mv, as exemplified: assuming that the calculated magnitudes are 10mv, 12mv, 20mv, 22mv, 21mv, 30mv, 31mv, respectively, the values of one of 10mv, 12mv, 22mv, 21mv, one of 30mv, 31mv, and 31mv are deleted, and only three values of 10mv, 20mv, and 30mv remain.

Of course, the following steps may be used instead of the steps S104, S106 within the scope of the person skilled in the art:

s104, the TDC chip sends an excitation signal to the transducer to be tested; the transducer to be measured is used as a transmitting transducer, generates vibration after receiving an excitation signal, and radiates sound waves into a medium; the standard transducer is used as a receiving transducer, sound waves in a medium act on the standard transducer, so that a mechanical vibration system of the standard transducer vibrates to cause corresponding changes of an electric field or a magnetic field in an energy storage element of the standard transducer, and an electric output end of the standard transducer generates an echo signal corresponding to the sound signal;

s106, the TDC chip receives echo signals returned by the standard transducer.

As a preferred implementation of this example, the method further comprises:

s114, recording the arrival time of each sine wave in echo signals received by the TDC chip, calculating the time difference of arrival time of two adjacent sine waves from the sine wave with the first amplitude exceeding the threshold value of the first wave, and judging that the working frequency of the transducer to be tested meets the standard if the values of the time differences are equal. The stability of the transducer is guaranteed, and for an ultrasonic water meter manufacturer, the detection efficiency of the transducer can be greatly improved.

In addition, by adopting the detection method of the embodiment, the pairing work of the transducers can be also performed: for the maximum amplitude of oscillation of the transducer to be tested, the transducers with the same or near maximum amplitude (generally referring to two transducers with amplitude differences of 0-5 mv) are paired.

The preferred embodiments of this invention have been described so far that various changes or modifications may be made by one of ordinary skill in the art without departing from the scope of this invention.

Claims (4)

1. The ultrasonic transducer detection method based on the TDC chip is characterized by comprising the following steps of:

s100, connecting the TDC chip with a transducer to be tested and a standard transducer in a communication way to form a loop;

s102, initializing a head wave threshold of a TDC chip;

s104, the TDC chip sends an excitation signal to the transducer to be tested or the standard transducer;

s106, the TDC chip receives echo signals returned by the standard transducer or the transducer to be tested;

s108, calculating the amplitude A of a sine wave with the first amplitude exceeding a head wave threshold value in the echo signals received by the TDC chip by using the following formula;

wherein A is amplitude, wave_set is a first wave threshold, wwave_set is a pulse width corresponding to the first wave threshold, and W0 is a standard half-wave pulse width of an echo signal received by the TDC chip;

s110, increasing the head wave threshold of the TDC chip, and executing the step S104 until the TDC chip is overtime;

and S112, for the amplitudes with the same or similar values in the calculated amplitudes, only one of the amplitudes is reserved, and the number of the rest amplitudes is recorded so as to reflect the vibration starting rate of the transducer to be tested.

2. The TDC chip-based ultrasonic transducer detection method according to claim 1, characterized in that the method further comprises:

s114, recording the arrival time of each sine wave in echo signals received by the TDC chip, calculating the time difference of arrival time of two adjacent sine waves from the sine wave with the first amplitude exceeding the threshold value of the first wave, and judging that the working frequency of the transducer to be tested meets the standard if the values of the time differences are equal.

3. The TDC chip-based ultrasonic transducer detection method according to claim 1, characterized in that the method further comprises:

s116, taking the amplitude with the largest value in the rest amplitude values in the step S112 as the largest amplitude value of the oscillation of the transducer to be tested.

4. The TDC chip-based ultrasonic transducer detection method according to claim 1, characterized in that: in the step S110, the increase amount of the threshold value of the head wave is 1-5mv.

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