Prediction method for sending voltage response of deep sea spherical piezoelectric transducer

Abstract

The invention relates to a forecasting method for sending voltage response of a deep-sea spherical piezoelectric transducer, and the method comprises the steps: analyzing the piezoelectric characteristics, radiation characteristics and sound field characteristics of the deep-sea spherical piezoelectric transducer according to the working characteristics of the deep-sea spherical piezoelectric transducer, and building a sending voltage response equivalent model of the deep-sea spherical piezoelectric transducer; and obtaining the magnitude of each parameter in the sending voltage response equivalent model of the deep-sea spherical piezoelectric transducer by using the impedance or admittance characteristics of the equivalent analysis model, thereby realizing the forecasting of the sending voltage response of the deep-sea spherical piezoelectric transducer. According to the method, the transmission voltage response of the deep-sea spherical piezoelectric transducer can be forecasted on the basis of impedance characteristics under the condition that deep-sea measurement is not carried out.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of underwater acoustic measurement, and particularly relates to a method for predicting the sending voltage response of a deep-sea spherical piezoelectric transducer. BACKGROUND

[0002] With the continuous development of underwater acoustic technology, the deep-sea spherical piezoelectric transducer can generate a sound field meeting the requirements under water, and has important applications in the measurement of deep-sea underwater acoustic equipment. The sending voltage response is an important technical index of the deep-sea spherical piezoelectric transducer. In the measurement process, a special high hydrostatic pressure deep-sea environment simulation system needs to be equipped to construct the measurement sound field conditions, and the measurement cost is high, the measurement process is complex, the research difficulty is great, and the related research progress is relatively slow. At the same time, the deep-sea environment simulation system needs to consider the hydrostatic pressure and the sound field conditions. In order to be able to withstand higher hydrostatic pressure, the structure of the deep-sea environment model system usually needs to have high enough pressure-bearing capacity. At this time, the internal space of the deep-sea environment simulation system is very limited, and the effect of the sound absorption wedge under deep-sea conditions is poor, and the reflected wave from the boundary will have a certain influence on the measurement. Therefore, under the condition of high hydrostatic pressure, the sending response measurement of the deep-sea spherical piezoelectric transducer has the following problems: (1) The simulation of the deep-sea high hydrostatic pressure environment condition is complex, and the equipment investment cost is high. The main method of hydrophone calibration is to simulate the deep-sea high hydrostatic pressure environment in the laboratory, which has huge investment, complex measurement process and long test cycle. (2) The sound field conditions required for measurement are strict, and the measurement is easily affected by the reflected wave under the condition of high hydrostatic pressure environment, and the low-frequency measurement is difficult.

[0003] Therefore, there is an urgent need for a deep-sea spherical transducer sending voltage response prediction method to make up for the deficiency of the current deep-sea spherical piezoelectric transducer sending voltage response measurement capability. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a method for predicting the sending voltage response of a deep-sea spherical piezoelectric transducer, which can be based on the impedance characteristics and can realize the prediction of the sending voltage response of the deep-sea spherical piezoelectric transducer without deep-sea measurement.

[0005] The technical solution of the present application is to provide a method for predicting the sending voltage response of a deep-sea spherical piezoelectric transducer. According to the working characteristics of the deep-sea spherical piezoelectric transducer, the piezoelectric characteristics, the radiation characteristics and the sound field characteristics are analyzed, the equivalent model of the sending voltage response of the deep-sea spherical piezoelectric transducer is established, the impedance or admittance (the reciprocal of impedance) characteristics of the equivalent analysis model are used to obtain the values of the parameters in the equivalent model of the sending voltage response of the deep-sea spherical piezoelectric transducer, and the prediction of the sending voltage response of the deep-sea spherical piezoelectric transducer is realized, wherein,

[0006] The sending voltage response equivalent model of the deep-sea spherical piezoelectric transducer can be expressed in the form of an equivalent circuit, and the surface vibration velocity of the deep-sea spherical piezoelectric transducer is equivalently represented by the excitation voltage, the excitation current and the admittance through equivalent circuit transformation and electromechanical conversion.

[0007] The present application can predict the sending voltage response of the deep-sea spherical piezoelectric transducer without the need for a large pressure tank. Compared with the traditional deep-sea spherical piezoelectric transducer sending voltage response measurement method, the present application establishes a precise measurement model, proposes a new idea of predicting the sending voltage response by using the model, further simplifies the deep-sea measurement process, and improves the efficiency.

[0008] As preferred, the deep-sea spherical piezoelectric transducer is driven by a power amplifier, the excitation voltage signal is U(t), the excitation current is I(t), the excitation voltage signal and the excitation current signal are subjected to Fourier transform, and the transformed signals are U(f) and I(f) respectively, both of which are complex numbers, the admittance under the transmission excitation condition is obtained by using the frequency response of the excitation current and the excitation voltage, and is expressed as:

[0009]

[0010] In the formula, G(f) is the admittance complex frequency response, and f is the frequency.

[0011] As preferred, the admittance complex frequency response G(f) can be expressed as |G(f)|exp[jθ(f)], and θ is the frequency response of the phase difference between the excitation current signal and the excitation voltage signal,

[0012] As preferred, the nonlinear least square method is used to estimate each parameter in the equivalent circuit admittance complex frequency response |G(f)| and the phase difference frequency response θ(f) under different hydrostatic pressures.

[0013] As preferred, the obtained estimation results are used to calculate the surface vibration velocity frequency response v(ω) of the deep-sea spherical piezoelectric transducer under different hydrostatic pressures according to the deep-sea spherical piezoelectric transducer sending voltage response equivalent model, and can be expressed as:

[0014]

[0015] In the formula, C is the compliance coefficient, m is the equivalent mass, R is the vibration loss, M is the radiation resistance, R is the radiation resistance, m m r r is the conversion coefficient, ω is the angular frequency, and ω=2πf.

[0016] ​​​​As preferred, the sending voltage response S v (ω) is expressed as:

[0017]

[0018] In the formula, ρ is the density of water, c is the sound speed in water, k is the wave number, and a is the radius of the spherical transducer.

[0019] As preferred, the specific operation is as follows,

[0020] S1, obtaining the sending current signal and the sending voltage signal of the deep-sea spherical piezoelectric transducer by using the deep-sea spherical transducer impedance or admittance measurement system under high hydrostatic pressure, measuring the phase between the sending voltage and the sending current by using an oscilloscope, and calculating the amplitude frequency response and the phase frequency response of the admittance;

[0021] S2, taking the amplitude frequency response and the phase frequency response of the admittance as a target function, and estimating the parameters in the impedance amplitude and phase under different hydrostatic pressures by using a least square fitting method;

[0022] S3, according to the sending voltage response equivalent model of the deep-sea spherical piezoelectric transducer, bringing the parameters estimated in the step S2 into the formula (2) and the formula (3), and predicting the sending voltage response of the deep-sea spherical piezoelectric transducer;

[0023] The deep-sea spherical transducer impedance or admittance measurement system is composed of a signal source, a power amplifier, a current-voltage sampler, a digital oscilloscope, and a small pressure container, wherein the small pressure container is a non-acoustic pressure container, and the oscilloscope has frequency analysis and phase analysis functions;

[0024]

[0025] In the formula, v(ω) is the surface vibration velocity frequency response of the deep-sea spherical piezoelectric transducer under different hydrostatic pressure conditions, C m is the compliance coefficient, m is the equivalent mass, R m is the vibration loss, M r is the radiation reactance, R r is the radiation resistance, is the conversion coefficient, ω is the angular frequency, and ω=2πf.

[0026]

[0027] In the formula, S v (ω) is the sending voltage response, ρ is the density of water, c is the sound speed in water, k is the wave number, and a is the radius of the spherical transducer.

[0028] Compared with the prior art, the present application has the following advantages:

[0029] The transmitting characteristic of the deep-sea transducer can be analyzed by using the equivalent circuit, and the transmitting voltage response of the deep-sea spherical transducer can be predicted by using the equivalent model. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The equivalent model of the deep-sea spherical piezoelectric transducer.

[0031] Figure 2 The block diagram of the equivalent model parameter measurement system of the deep-sea spherical piezoelectric transducer. DETAILED DESCRIPTION

[0032] The application will be further described in the specific embodiments in combination with the drawings:

[0033] The application discloses a method for predicting the dynamic change of the transmitting voltage response of a deep-sea spherical piezoelectric transducer with hydrostatic pressure, which needs to establish an equivalent model of the transmitting voltage response of the deep-sea spherical piezoelectric transducer. Figure 1 As shown in the figure, V is the open circuit voltage, I is the output current, C0 is the static capacitance, is the conversion coefficient, C m is the compliance coefficient, m is the equivalent mass, R m is the vibration loss, Z r is the radiation impedance, R r is the radiation resistance, M r is the radiation resistance.

[0034] The measurement system for measuring the impedance of the deep-sea spherical transducer is composed of a signal source, a power amplifier, a current-voltage sampler, a digital oscilloscope and a small pressure container, wherein the small pressure container is a non-acoustic pressure container, which is usually above 100cm*50cm*50cm in size relative to a large pressure container, and the oscilloscope has frequency analysis and phase analysis functions, as shown in the figure. Figure 2

[0035] The specific operation steps are as follows:

[0036] (1) install the deep-sea spherical piezoelectric transducer to be measured in the small pressure container;

[0037] (2) apply a certain hydrostatic pressure in the pressure container and keep the pressure for a period of time;

[0038] ​(3) Signal source stimulates transducer through power amplifier, transducer generates sound wave in high hydrostatic pressure tank, voltage and current signals output by current voltage sampler are measured at different frequencies, and voltage U(t), current I(t) signals and phase difference theta at different frequencies are obtained by oscilloscope;

[0039] (4) m, R, C, Z and other parameter values in equivalent model of sending voltage response of deep-sea spherical piezoelectric transducer are calculated according to admittance frequency response curves under different hydrostatic pressure conditions by using nonlinear least square fitting algorithm. m m r

[0040] (5) parameters obtained in step (4) are brought into calculation formula, and surface vibration velocity frequency response v(omega) of deep-sea spherical piezoelectric transducer under different hydrostatic pressure conditions is calculated.

[0041]

[0042] Sending voltage response of deep-sea piezoelectric spherical transducer can be calculated by using obtained surface vibration velocity frequency response.

[0043]

[0044] In the formula, rho is the density of water, c is the sound speed in water, k is the wave number, and a is the radius of the spherical transducer.

[0045] Compared with the traditional deep-sea spherical piezoelectric transducer sending voltage response measurement method, the application establishes a precise measurement model, proposes a new idea of predicting sending voltage response by using the model, further simplifies the deep-sea measurement process, and can predict the sending voltage response of the piezoelectric transducer without the need of high static pressure acoustic measurement environment, thereby improving the efficiency. According to the working principle of the deep-sea spherical piezoelectric transducer, an equivalent model based on piezoelectric characteristics and radiation characteristics is established, nonlinear fitting technology is used to estimate each parameter in the deep-sea spherical piezoelectric transducer model, and the estimated parameters are used to predict the sending voltage response of the deep-sea spherical piezoelectric transducer under high hydrostatic pressure, thereby making up for the deficiency of current deep-sea underwater electroacoustic parameter measurement capability.

[0046] The above only describes the preferred embodiments of the application, but cannot be understood as limiting the claims. Any equivalent process transformation made by using the application description is included in the patent protection scope of the application.​​​

Claims

1. A method for predicting the voltage response of a deep-sea spherical piezoelectric transducer, characterized by: According to the working characteristics of the deep-sea spherical piezoelectric transducer, its piezoelectric characteristics, radiation characteristics and acoustic field characteristics are analyzed, and an equivalent model of the deep-sea spherical piezoelectric transducer sending voltage response is established. The impedance or admittance characteristics of the equivalent analysis model are used to obtain the values ​​of each parameter in the equivalent model of the deep-sea spherical piezoelectric transducer sending voltage response, and the prediction of the deep-sea spherical piezoelectric transducer sending voltage response is realized. The equivalent model of the voltage response of the deep-sea spherical piezoelectric transducer can be expressed in the form of an equivalent circuit. Through equivalent circuit transformation and electromechanical conversion, the surface vibration velocity of the deep-sea spherical piezoelectric transducer is equivalently expressed by excitation voltage, excitation current and admittance.

2. The method for predicting the voltage response of a deep-sea spherical piezoelectric transducer according to claim 1, characterized in that: A power amplifier is used to drive the deep-sea spherical piezoelectric transducer. The excitation voltage signal is U(t) and the excitation current is I(t). The excitation voltage signal and the excitation current signal are Fourier transformed. After the transformation, they are U(f) and I(f), respectively. Both are complex numbers. The admittance under the transmission excitation condition is obtained by using the frequency response of the excitation current and the excitation voltage, which is expressed as: Where G(f) is the complex frequency response of admittance and f is the frequency.

3. The method for predicting the voltage response of a deep-sea spherical piezoelectric transducer according to claim 2, characterized in that: The complex frequency response of admittance G(f) can be expressed as |G(f)|exp[jθ(f)], where θ is the frequency response of the phase difference between the excitation current signal and the excitation voltage signal.

4. The method for predicting the voltage response of a deep-sea spherical piezoelectric transducer according to claim 3, characterized in that: The parameters of the equivalent circuit admittance complex frequency response |G(f)| and phase difference frequency response θ(f) are estimated under different hydrostatic pressures using the nonlinear least squares method.

5. The method for predicting the voltage response of a deep-sea spherical piezoelectric transducer according to claim 4, characterized in that: Using the obtained estimation results, the surface vibration velocity frequency response v(ω) of the deep-sea spherical piezoelectric transducer under different hydrostatic pressure conditions is calculated according to the equivalent model of the voltage response of the deep-sea spherical piezoelectric transducer, which can be expressed as: Where C m is the compliance coefficient, m is the equivalent mass, R m is the vibration loss, M r R is the radiation resistance r is the radiation resistance, is the conversion coefficient, ω is the angular frequency, ω=2πf.

6. The method for predicting the voltage response of a deep-sea spherical piezoelectric transducer according to claim 5, characterized in that: The transmission voltage response S can be calculated by using the surface vibration frequency response of the deep-sea piezoelectric spherical transducer. v (ω), expressed as: Where ρ is the density of water, c is the speed of sound in water, k is the wave number, and a is the radius of the spherical transducer.

7. The method for predicting the voltage response of a deep-sea spherical piezoelectric transducer according to claim 1, characterized in that: The specific operations are as follows: S1. Under high hydrostatic pressure, using a deep-sea spherical transducer impedance or admittance measurement system, obtain the emission current signal and emission voltage signal of the deep-sea spherical piezoelectric transducer, use an oscilloscope to measure the phase between the emission voltage and the emission current, and calculate the amplitude frequency response and phase frequency response of the admittance; S2. Taking the amplitude frequency response and phase frequency response of admittance as the objective function, the least square fitting method is used to estimate the parameters of impedance amplitude and phase under different hydrostatic pressures; S3. According to the equivalent model of the voltage response of the deep-sea spherical piezoelectric transducer, the parameters estimated in step S2 are substituted into equations (2) and (3) to predict the voltage response of the deep-sea spherical piezoelectric transducer. The measurement system of the impedance or admittance of the deep-sea spherical transducer is composed of a signal source, a power amplifier, a current and voltage sampler, a digital oscilloscope, and a small pressure vessel. The small pressure vessel is a non-acoustic pressure vessel, and the oscilloscope has frequency analysis and phase analysis functions. Where v(ω) is the surface vibration frequency response of the deep-sea spherical piezoelectric transducer under different hydrostatic pressure conditions, C m is the compliance coefficient, m is the equivalent mass, R m is the vibration loss, M r R is the radiation resistance r is the radiation resistance, is the conversion coefficient, ω is the angular frequency, ω=2πf; Where S v (ω) is the transmitted voltage response, ρ is the density of water, c is the speed of sound in water, k is the wave number, and a is the radius of the spherical transducer.

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