Ultrasonic Transducer Detection Method Based on TDC Chip

Abstract

The present invention relates to the technical field of ultrasonic transducer detection methods, and in particular to an ultrasonic transducer detection method based on a TDC chip. Technical solution of the present invention: The TDC chip is respectively communicatively connected to the transducer under test and the standard transducer to form a loop; the first-wave threshold of the TDC chip is initialized; the TDC chip sends an excitation signal to the transducer under test or the standard transducer; the TDC chip receives the echo signal returned by the standard transducer or the transducer under test; calculate the amplitude A of the first sine wave whose amplitude exceeds the first-wave threshold in the echo signal received by the TDC chip; increase the first-wave threshold of the TDC chip until a timeout of the TDC chip occurs; for the amplitudes with the same or similar numerical values among the calculated amplitudes, only one amplitude is retained, and the number of the remaining amplitudes is recorded to reflect the startup rate of the transducer under test. This detection method uses fewer tools, has a simpler detection process, lower detection costs, and higher detection efficiency.

Description

Technical Field

[0001] The present invention relates to a detection method for an ultrasonic transducer, specifically a detection method for an ultrasonic transducer based on a TDC chip. Background Art

[0002] In the ultrasonic water meter industry, the transducer is a crucial part that plays a decisive role. It is the basis of ultrasonic measurement and determines the accuracy of measurement.

[0003] Currently, the detection of ultrasonic transducers mainly relies on the detection by the transducer manufacturer before the product leaves the factory. Thus, the product quality of ultrasonic water meters largely depends on the detection of transducers by the transducer manufacturer. For ultrasonic water meter manufacturers, such a situation makes it impossible to fully control the product quality. However, if ultrasonic water meter manufacturers detect the transducers, the cost is relatively high. It requires a number of tools such as corresponding oscilloscopes, spectrum analyzers, and multimeters, and the time cost is also high. The labor and time costs are large. It is not suitable for ultrasonic water meter enterprises to conduct full inspections on transducers, and it is easy to repeat the work of the upstream industry. Therefore, the industry urgently needs a transducer detection method with low cost. Summary of the Invention

[0004] The purpose of the present invention is to provide a detection method for an ultrasonic transducer based on a TDC chip in view of the above problems.

[0005] To achieve the above purpose, the present invention is realized through the following technical solutions:

[0006] A detection method for an ultrasonic transducer based on a TDC chip, comprising:

[0007] S100. Communicatively connect the TDC chip with the transducer to be measured and the standard transducer respectively to form a loop;

[0008] S102. Initialize the first-wave threshold of the TDC chip;

[0009] S104. The TDC chip sends an excitation signal to the transducer to be measured or the standard transducer;

[0010] S106. The TDC chip receives the echo signal returned by the standard transducer or the transducer to be measured;

[0011] S108. Use the following formula to calculate the amplitude A of the sine wave whose first amplitude exceeds the first-wave threshold in the echo signal received by the TDC chip;

[0012]

[0013]

[0014] Wherein, A is the amplitude, wave_set is the first-wave threshold, Wwave_set is the pulse width corresponding to the first-wave threshold, and W0 is the standard half-wave pulse width of the echo signal received by the TDC chip;

[0015] S110. Increase the first-wave threshold of the TDC chip, and execute step S104 until the TDC chip times out;

[0016] S112. For the amplitudes with the same or similar numerical values among the calculated amplitudes, only retain one of them, and record the number of the remaining amplitudes to reflect the starting oscillation rate of the transducer under test.

[0017] Preferably, the method further includes:

[0018] S114. Record the arrival time of each sine wave in the echo signal received by the TDC chip. Starting from the sine wave whose first amplitude exceeds the first-wave threshold, calculate the time difference between the arrival times of two adjacent sine waves. If the values of the time differences are all equal, it is determined that the operating frequency of the transducer under test meets the standard.

[0019] Preferably, the method further includes:

[0020] S116. Use the amplitude with the largest numerical value among the remaining amplitudes in step S112 as the maximum amplitude that the transducer under test can oscillate.

[0021] Preferably, in step S110, the increase amount of the first-wave threshold is 1 - 5 mv.

[0022] The beneficial effects of the present invention are as follows:

[0023] 1. The present invention uses the trigonometric function principle to calculate the amplitude A of the sine wave whose first amplitude exceeds the first-wave threshold in the echo signal received by the TDC chip. By continuously changing the first-wave threshold of the TDC chip, multiple different amplitudes A can be obtained until the TDC chip times out. For the amplitudes with the same or similar numerical values among the calculated amplitudes, only retain one of them, and record the number of the remaining amplitudes. The number of these remaining amplitudes can reflect the starting oscillation rate of the transducer under test, and the amplitude with the largest numerical value among the remaining amplitudes is the maximum amplitude that the transducer under test can oscillate. Compared with the prior art, this detection method uses fewer tools, has a simpler detection process, lower detection costs, and higher detection efficiency.

[0024] 2. This solution is highly targeted and suitable for ultrasonic water meter manufacturers using TDC chips. It also perfectly conforms to the metering waveform principle of TDC chips. Meanwhile, important parameters such as the amplitude of the waveform, the number of amplitudes during the process from the waveform start to the TDC chip timeout (for amplitudes with the same or similar values, only one amplitude is retained), and the time difference between the arrival times of two adjacent sine waves can be displayed on the host computer to assist in manual data analysis. Brief Description of the Drawings

[0025] Figure 1 It is the TDC chip of the present invention and its peripheral circuit diagram.

[0026] Figure 2 It is the schematic diagram of the detection method process of the present invention. Detailed Embodiment

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] The example of the present invention mainly uses the principle of trigonometric functions to restore the sine wave through the formula Asin(x), and sets the first wave threshold (wave_set) of the TDC chip using the TDC chip to restore the peak of the sine wave where the first wave threshold is located: Assume the first wave threshold of the TDC chip is 10mv, and the obtained half-wavelength ratio is 0.4 (that is, the ratio of the pulse width corresponding to the current first wave threshold to the standard half-wave pulse width is 0.4). Then, through the formula Calculate the x value to obtain the position of the first wave threshold of the TDC chip in the current wave, and then calculate the amplitude A as 12mv through the formula Asin(54°) = 10mv.

[0029] Using this principle, by continuously changing the first-wave threshold of the TDC chip, multiple A values can be obtained. According to the characteristics of the transducer, when the number of excitations of the TDC chip (the square wave sent by the TDC chip) is sufficient, the oscillation of the transducer will definitely reach the peak of an amplitude value. It can be understood in this way that when the transducer (the transducer at this time is the receiving transducer) receives the first wave, it generates an oscillation with an intensity of X. When it receives the second wave, the oscillation of the first wave has not ended yet. Since the first wave and the second wave have the same phase, they can be superimposed, that is, an intensity of 2X. However, the maximum intensity that the transducer can oscillate in total is only Y. That is, when nX > Y (n is the nth wave received by the transducer), the transducer can only exhibit an oscillation of Y. Therefore, the value of the last amplitude must be Y. When the first-wave threshold of the TDC chip is greater than the Y value, the amplitude of the signal cannot be read out, resulting in the situation of TDC chip timeout.

[0030] As Figure 2 shown, a method for detecting an ultrasonic transducer based on a TDC chip in this embodiment includes:

[0031] S100. Communicatively connect the TDC chip to the transducer under test and the standard transducer respectively to form a loop; specifically, in this example, the TDC chip uses an ultrasonic flow measurement chip with the model number MS1030. Connect Figure 1 the pin UP in it to the signal line (usually red) of the standard transducer, and connect the pin AGND to the ground wire (usually white) of the standard transducer; connect Figure 1 the pin DOWN in it to the signal line (usually red) of the transducer under test, and connect the pin AGND to the ground wire (usually white) of the transducer under test;

[0032] S102. Initialize the first-wave threshold of the TDC chip;

[0033] S104. The TDC chip sends an excitation signal to the standard transducer; the standard transducer acts as a transmitting transducer. After receiving the excitation signal, it generates vibrations and radiates sound waves into the medium; the transducer under test acts as a receiving transducer. The sound waves in the medium act on the transducer under test, thereby causing the mechanical vibration system of the transducer under test to vibrate, causing corresponding changes in the electric field or magnetic field in the energy storage element of the transducer under test, and making the electrical output terminal of the transducer under test generate an echo signal corresponding to the sound signal;

[0034] S106. The TDC chip receives the echo signal returned by the transducer under test;

[0035] S108. Use the following formula to calculate the amplitude A of the sine wave whose first amplitude in the echo signal received by the TDC chip exceeds the first-wave threshold;

[0036]

[0037]

[0038] Wherein, A is the amplitude; wave_set is the first wave threshold; Wwave_set is the pulse width corresponding to the first wave threshold, which can be directly read from the register of the TDC chip (the TDC chip will record the rising edge time and falling edge time of the echo signal / sine wave corresponding to the first wave threshold, and store the difference between the two times in the register as the pulse width corresponding to the first wave threshold); W0 is the standard half-wave pulse width of the echo signal received by the TDC chip, and this standard half-wave pulse width is related to the oscillation frequency of the standard transducer or the transducer to be measured. Assuming the oscillation frequency of the standard transducer or the transducer to be measured is 1 megahertz, then the standard half-wave pulse width is 0.5 microseconds;

[0039] S110. Increase the first wave threshold of the TDC chip, and execute step S104 until the TDC chip times out; the increase amount of the first wave threshold is 1 - 5 mv;

[0040] S112. For the amplitudes with the same or similar values among the calculated amplitudes, only retain one of the amplitudes, record the number of the remaining amplitudes, and the number of these remaining amplitudes can reflect the starting oscillation rate of the transducer to be measured (the more the number of the remaining amplitudes, the slower the starting oscillation rate; on the contrary, it indicates that the starting oscillation rate is faster). The largest amplitude value among the remaining amplitudes is the maximum amplitude that the transducer to be measured can oscillate. Compared with the prior art, this detection method uses fewer tools, has a simpler detection process, lower detection cost, and higher detection efficiency. Usually, if the number of these remaining amplitudes is less than or equal to 3, it is determined that the starting oscillation rate of the transducer to be measured meets the requirements; if the largest amplitude value among the remaining amplitudes is within the range of 130 - 250 mv, it is determined that the maximum amplitude that the transducer to be measured can oscillate meets the requirements.

[0041] For the amplitudes with the same or similar values mentioned above, generally, the standard is that the difference does not exceed 5 mv. For example: Suppose the calculated amplitudes are 10 mv, 10 mv, 12 mv, 20 mv, 22 mv, 21 mv, 30 mv, 30 mv, 31 mv, 31 mv respectively, then delete the values of one of the 10 mv, 12 mv, 22 mv, 21 mv, one of the 30 mv, 31 mv, 31 mv, and only retain the three values of 10 mv, 20 mv, and 30 mv.

[0042] Of course, within the optional range of those skilled in the art, the aforementioned steps S104 and S106 can also be replaced by the following steps:

[0043] S104. The TDC chip sends an excitation signal to the transducer under test. The transducer under test acts as a transmitting transducer. After receiving the excitation signal, it generates vibrations and radiates sound waves into the medium. The standard transducer acts as a receiving transducer. The sound waves in the medium act on the standard transducer, causing the mechanical vibration system of the standard transducer to vibrate, which in turn causes a corresponding change in the electric or magnetic field in the energy storage element of the standard transducer, resulting in an echo signal corresponding to the acoustic signal being generated at the electrical output terminal of the standard transducer.

[0044] S106. The TDC chip receives the echo signal returned by the standard transducer.

[0045] As a preferred implementation of this embodiment, the method further includes:

[0046] S114. Record the arrival time of each sine wave in the echo signal received by the TDC chip. Starting from the sine wave whose first amplitude exceeds the first wave threshold, calculate the time difference between the arrival times of two adjacent sine waves. If the values of all the time differences are equal, it is determined that the operating frequency of the transducer under test meets the standard. This ensures the stability of the transducer. For ultrasonic water meter manufacturers, such a tooling can greatly improve the detection efficiency of the transducer.

[0047] In addition, by using the detection method of this embodiment, it is also possible to perform the pairing operation of the transducers: for the maximum amplitude that the transducer under test can oscillate, pair the transducers with the same or close maximum amplitudes (generally referring to two transducers with an amplitude difference of 0 - 5 mV).

[0048] The best embodiments of the present invention have been illustrated, and various changes or modifications made by those of ordinary skill in the art will not depart from the scope of the present invention.

Claims

1. An ultrasonic transducer detection method based on a TDC chip, characterized in that Including: S100. Communicate and connect the TDC chip with the transducer under test and the standard transducer respectively to form a loop; S102. Initialize the first-wave threshold of the TDC chip; S104. The TDC chip sends an excitation signal to the transducer under test or the standard transducer; S106. The TDC chip receives the echo signal returned by the standard transducer or the transducer under test; S108. Calculate the amplitude A of the sine wave whose first amplitude exceeds the first-wave threshold in the echo signal received by the TDC chip using the following formula; In the formula, A is the amplitude, wave_set is the first-wave threshold, Wwave_set is the pulse width corresponding to the first-wave threshold, and W0 is the standard half-wave pulse width of the echo signal received by the TDC chip; S110. Increase the first-wave threshold of the TDC chip and execute step S104 until the TDC chip times out; S112. For the amplitudes with the same or similar values among the calculated amplitudes, only retain one of them, and record the number of the remaining amplitudes to reflect the starting oscillation rate of the transducer under test.

2. The ultrasonic transducer detection method based on the TDC chip according to claim 1, wherein The method further includes: S114. Record the arrival time of each sine wave in the echo signal received by the TDC chip. Starting from the sine wave whose first amplitude exceeds the first-wave threshold, calculate the time difference between the arrival times of two adjacent sine waves. If the values of each time difference are equal, it is determined that the operating frequency of the transducer under test meets the standard.

3. The ultrasonic transducer detection method based on a TDC chip according to claim 1, characterized in that, The method further includes: S116. Use the largest amplitude value among the remaining amplitudes in step S112 as the maximum amplitude that the transducer under test can oscillate.

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

Images