Piezoelectric transducer multi-objective intelligent optimization design method

Abstract

The invention belongs to the technical field of ultrasonic transducers and artificial intelligence, and particularly discloses a piezoelectric transducer multi-target intelligent optimization design method which comprises the following steps: collecting performance data of a piezoelectric transducer, and performing data cleaning on the performance data; establishing a piezoelectric transducer model by using the processed data; and calculating the piezoelectric transducer model by using an NSGA-II multi-objective optimization algorithm to obtain optimal transducer design parameters, and completing the multi-objective intelligent optimization design of the piezoelectric transducer. According to the method, a more scientific and effective means is provided for design and optimization of the transducer by comprehensively applying a model establishment and multi-objective optimization method, and the problem that a large amount of time, manpower and resources need to be consumed by a manual experiment technology in the design of the piezoelectric transducer is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of ultrasonic transducers and artificial intelligence, and specifically relates to a multi-objective intelligent optimization design method for a piezoelectric transducer. Background Art

[0002] At present, in the research of ultrasonic sensors, the material settings of each component are mostly obtained through a large number of manual experiments and comparisons. However, manual evaluation of sensor materials may be affected by individual subjective opinions and the limitations of individual knowledge and experience. Different experts may have different views and preferences, resulting in inconsistent selection results and difficulty in discovering new materials or breakthrough performance. On the other hand, the selection of sensor materials usually requires a large number of experiments and tests, as well as repeated evaluations and adjustments. These processes require a lot of time, manpower and resources, especially when there are a large number of material candidates or the evaluation criteria are complex, the cost and time cost of manual optimization will be more significant. Summary of the invention

[0003] The purpose of the present invention is to solve the problem that manual experimental technology in the design of piezoelectric transducers requires a lot of time, manpower and resources, and proposes a multi-objective intelligent optimization design method for piezoelectric transducers.

[0004] The technical solution of the present invention is: a multi-objective intelligent optimization design method for a piezoelectric transducer, comprising the following steps:

[0005] S1. Collecting performance data of the piezoelectric transducer and performing data cleaning on the performance data;

[0006] S2. Establishing a piezoelectric transducer model using the processed data;

[0007] S3. Use the NSGA-Ⅱ multi-objective optimization algorithm to calculate the piezoelectric transducer model, obtain the optimal transducer design parameters, and complete the multi-objective intelligent optimization design of the piezoelectric transducer.

[0008] The beneficial effects of the present invention are:

[0009] In the present invention, an intelligent algorithm is introduced into the optimization design of a piezoelectric transducer, which can search for the optimal solution more quickly in the design space, thereby improving design efficiency and reducing experimental costs, and helping to promote technological innovation and development. By continuously exploring and optimizing the design space, new ideas and methods can then be introduced to promote the advancement of transducer technology and improve its performance and efficiency in various application fields.

[0010] Preferably, the performance data in step S1 includes voltage-displacement curve, frequency response curve, sound pressure level curve, electroacoustic conversion efficiency, characteristic parameters of piezoelectric materials, temperature characteristics, durability test data and environmental factors.

[0011] Preferably, the step S1 specifically includes the following sub-steps:

[0012] S11. Collect performance data of piezoelectric transducers using sensors and graphical programming tools;

[0013] S12. Based on a graphical programming tool, a relational database is constructed, and the performance data and material property data of the piezoelectric transducer collected by the sensor are stored in the relational database;

[0014] S13. Perform data cleaning on the performance data and material property data of the piezoelectric transducer in the relational database.

[0015] Preferably, the data cleaning in step S13 includes removing duplicate data, processing missing values, and verifying the integrity and consistency of the data.

[0016] Preferably, the objective function of the piezoelectric transducer model in step S2 is:

[0017] minF(x)={f1(x),f2(x),f3(x)}

[0018] Among them, min means minimization, F(x) represents the piezoelectric transducer model; f1(x) represents the maximization of the radiated sound source level; f2(x) represents the minimization of the input electric power; f3(x) represents the minimization of the mass, and we have:

[0019]

[0020] Where SL represents the radiation sound source level, |P represents the sound source intensity, lg represents the logarithmic function with base 10, and P in represents input power, Z represents impedance, V rms represents the driving voltage and m represents the mass.

[0021] Preferably, the constraints of the piezoelectric transducer model in step S2 include resonance frequency constraints, material parameter constraints, upper and lower limits of sound source level constraints, piezoelectric material thickness limit constraints, piezoelectric material minimum radial dimension constraints, depolarization field strength constraints and transducer working power capacity constraints;

[0022] The expression formula of the resonant frequency constraint is:

[0023]

[0024] Among them, f s represents the resonant frequency, f low Indicates the lower limit of operating frequency, f up Indicates the upper limit of the operating frequency, l crepresents the thickness of the piezoelectric material, represents the elastic modulus, σ E represents the Poisson's ratio of the piezoelectric material, and ρ represents the density of the piezoelectric material;

[0025] The material parameter constraint is expressed as:

[0026] mat=mat i ,i=1,2,...,q

[0027] Among them, mat represents the piezoelectric material property parameters, q represents the total number of piezoelectric material types, mat i represents the property parameters of the i-th piezoelectric material;

[0028] The expression formula of the upper and lower limit constraints of the sound source level is:

[0029]

[0030] in, Indicates the lower limit of the sound source level, SL fup Indicates the upper limit of the sound source level, SL1 indicates the lower limit of the sound source level, and SL2 indicates the upper limit of the sound source level;

[0031] The expression formula of the piezoelectric material thickness limit constraint is:

[0032] l c ≥L0

[0033] Wherein, L0 represents the thickness limit value;

[0034] The expression formula of the minimum radial dimension constraint of the piezoelectric material is:

[0035] r≥R0

[0036] Where r represents the minimum radial dimension of the piezoelectric material, and R0 represents the radius limit of the actual process;

[0037] The expression formula of the depolarization field strength constraint is:

[0038]

[0039] Among them, V rms represents the driving voltage, E0 represents the reference electric field;

[0040] The expression formula of the transducer working power capacity constraint is:

[0041]

[0042] Where P represents the radiated sound power, P Mrepresents the power fatigue limit, π represents the circumference, f0 represents the resonant frequency of the transducer, V represents the voltage across the piezoelectric material, T0 represents the tensile strength, S represents the area of ​​the transducer, Q M Expressing the mechanical quality factor, we have:

[0043] Q m =1 / 4π(C0+C1)R1Δf

[0044] Wherein, C0 represents the static capacitance of the piezoelectric material, C1 represents the dynamic capacitance of the piezoelectric material, R1 represents the equivalent resistance at resonance, and Δf represents the difference between the resonant frequency and the anti-resonant frequency.

[0045] Preferably, the hybrid decision vector of the piezoelectric transducer model in step S2 is:

[0046] x T ={mat T ,r,l c ,V rms ,f low ,f up} T

[0047] Among them, x T represents the transpose of the hybrid decision vector of the piezoelectric transducer model, r represents the minimum radial size of the piezoelectric material, l c Represents the single crystal thickness, V rms represents the driving voltage, f low Indicates the lower limit of operating frequency, f up Indicates the upper limit of the operating frequency, mat T The transpose of the piezoelectric material property parameter mat is:

[0048]

[0049] Among them, d 33 represents the piezoelectric constant, s represents the mechanical strain, ρ represents the density of the piezoelectric material, ε 33 represents the dielectric constant, σ E represents the Poisson's ratio of the piezoelectric material.

[0050] Preferably, the step S3 specifically comprises the following steps:

[0051] S31. Initialize the operating parameters of the NSGA-Ⅱ multi-objective optimization algorithm and randomly generate an initial population P of size N according to the objective function of the piezoelectric transducer model. k , the initial value of the population generation k is 0, and P k As the parent population, the initial population P k Design parameters for the transducer to be optimized;

[0052] S32. For the parent population P k The selection operation, simulated binary crossover operation and polynomial mutation operation are performed in sequence to obtain the offspring population D k ;

[0053] S33. According to the elite selection strategy and the constraints of the piezoelectric transducer model, from the parent population P k and D in the progeny population k Select elite individuals that meet the constraints, use the elite individuals as the parent population in the next generation genetic algorithm, and increase the generation number k of the population by 1, and execute step S34;

[0054] S34. Determine whether the number of evolution times has reached the maximum value. If not, return to step S32; if reached, end the operation and take the last generation of population as the optimal solution, that is, the optimal transducer design parameters, to complete the multi-objective intelligent optimization design of the piezoelectric transducer.

[0055] Preferably, the optimal solution in step S34 is expressed as:

[0056] PF*={F(x*)= { f1(x*),f2(x*),f3(x*) } x*∈P*}

[0057] Among them, PF* represents the optimal solution, F(x * ) represents the optimal solution of the piezoelectric transducer model, f1(x * ) represents the optimal solution for maximizing the radiation sound source level, f2(x * ) represents the optimal solution for minimizing the input power, f3(x * ) represents the optimal solution for minimizing mass, x * The optimal solution of the hybrid decision vector representing the piezoelectric transducer model, P * It represents the optimization solution space of the design parameter space, that is, the optimal set of transducer design parameters.

[0058] The beneficial effects of the above preferred solution are:

[0059] 1. In the above preferred solution, the performance data and material property data of the piezoelectric transducer are integrated into the same database, which can provide researchers with a more comprehensive data perspective, enable comprehensive analysis and visualization of the performance and material properties of the sensor on the same platform, identify potential optimization space and improvement direction, and help to subsequently optimize the transducer design and improve the performance, stability and reliability of the sensor.

[0060] 2. In the above preferred scheme, the multi-objective optimization algorithm can consider multiple performance indicators at the same time. In this way, the research can provide a more comprehensive and accurate performance evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 Shown is a flow chart of a multi-objective intelligent optimization design method for piezoelectric transducers.

[0062] Figure 2 Shown is the overall design diagram of the multi-channel dynamic signal acquisition system software provided in an embodiment of the present invention.

[0063] Figure 3 Shown is a schematic diagram of a geometric model of a piezoelectric transducer provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0064] Now, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood that the embodiments shown and described in the accompanying drawings are only exemplary and are intended to explain the principles and spirit of the present invention, rather than to limit the scope of the present invention.

[0065] Example:

[0066] like Figure 1 As shown, a multi-objective intelligent optimization design method for a piezoelectric transducer includes the following steps:

[0067] S1. Collecting performance data of the piezoelectric transducer and performing data cleaning on the performance data;

[0068] S2. Establishing a piezoelectric transducer model using the processed data;

[0069] S3. Use the NSGA-Ⅱ multi-objective optimization algorithm to calculate the piezoelectric transducer model, obtain the optimal transducer design parameters, and complete the multi-objective intelligent optimization design of the piezoelectric transducer.

[0070] In this embodiment, the performance data in step S1 include voltage-displacement curve, frequency response curve, sound pressure level curve, electroacoustic conversion efficiency, characteristic parameters of piezoelectric materials, temperature characteristics, durability test data and environmental factors. These data can come from laboratory tests, simulation calculations or previous research literature.

[0071] The voltage-displacement curve is the displacement or amplitude response of the transducer at different voltages; the frequency response curve is the response of the transducer at different frequencies; the sound pressure level curve is the sound pressure level generated by the transducer at different frequencies; the electroacoustic conversion efficiency is the comparison of input electrical energy and output acoustic energy; the characteristic parameters of the piezoelectric material include piezoelectric coefficient, dielectric constant and mechanical stiffness, etc.; the temperature characteristics are the performance changes of the transducer at different temperatures; the durability test data includes long-term continuous operation, cyclic load testing, etc., to evaluate the durability and stability of the transducer; the environmental factors are used to consider the performance of the transducer under different environmental conditions, such as humidity, pressure, dust, etc.

[0072] In this embodiment, step S1 specifically includes the following sub-steps:

[0073] S11. Collect performance data of piezoelectric transducers using sensors and graphical programming tools;

[0074] S12. Based on a graphical programming tool, a relational database is constructed, and the performance data and material property data of the piezoelectric transducer collected by the sensor are stored in the relational database;

[0075] S13. Perform data cleaning on the performance data and material property data of the piezoelectric transducer in the relational database.

[0076] In step S11, during data acquisition, the sensor is connected to the USB-6366 high-speed acquisition module, and the USB-6366 high-speed acquisition module is connected to the computer, LabVIEW is used for software development, and the channels of the USB-6366 high-speed acquisition module are configured in LabVIEW to simultaneously acquire signals such as voltage, current, impedance phase, amplitude, and vibration speed, and set parameters such as sampling rate and sampling accuracy. The USB-6366 module is accessed in LabVIEW through the DAQmx driver of NI, which specifically includes the following steps:

[0077] A1. Install the NI-DAQmx driver, which is the key to communicating with NI hardware devices;

[0078] A2. Create a new VI in LabVIEW. In the LabVIEW toolbar, click “Functions” > “Express” > “NI-DAQmx” to add the NI-DAQmx module. In this module, you can find the “DAQAssistant” to help configure the USB-6366 module.

[0079] A3. Select input channel - In the DAQ Assistant, select the input channel of the USB-6366 module. You can also select the correct input channel according to your actual needs, such as analog input channel or digital input channel.

[0080] A4. Set the sampling rate and sampling accuracy - In the DAQ Assistant, you can set parameters such as sampling rate and sampling accuracy. The sampling rate determines how many data points are collected per second, and the sampling accuracy determines the accuracy of each data point.

[0081] A5. After completing the configuration of channels and parameters, click the "Finish" button to generate the configuration code.

[0082] After the settings are completed, follow Figure 2 The overall design diagram of the piezoelectric ultrasonic transducer multi-channel dynamic signal acquisition system software is shown. The LabVIEW program is written using a loop structure or an event structure to continuously collect data.

[0083] In step S12, when storing data, the embodiment of the present invention uses the provided database connection tool in LabVIEW to store the data in a table in a relational database (such as MySQL, PostgreSQL, etc.). Material properties can be manually input into the table in the relational database, and then an associated SQL statement is established to associate the two tables, for example:

[0084] Table 1 Sensor data table name: sensor_data; columns: timestamp, voltage, current, impedance phase, amplitude, and vibration speed;

[0085] Table 2 Transducer material test table name: transducer_material_test; columns: timestamp, material name, piezoelectric coefficient, dielectric constant, and mechanical stiffness, etc.;

[0086] The timestamp is the key to the association between the two tables. By using a timestamp column in both tables, the two tables can be connected by the timestamp. Of course, if the data has other unique identifiers, such as the test name, these identifiers can also be used to establish the association. In this way, the sensor test data and the transducer material data can be used together in the query to conduct a more comprehensive analysis and understand the sensor performance and material characteristics.

[0087] In this embodiment, the data cleaning in step S13 includes removing duplicate data, processing missing values, and verifying the integrity and consistency of the data.

[0088] In this embodiment, the piezoelectric transducer model is as follows: Figure 3 As shown, according to the piezoelectric equation:

[0089]

[0090] Among them, T3 represents stress, E3 represents electric field, S3 represents strain, D3 represents electric displacement, and h 33 represents the piezoelectric stiffness coefficient, C3 D 3 represents the elastic coefficient (constant electric displacement), represents the dielectric constant (constant strain); Figure 3 Take a small section dz in the slice, the stresses at its two end faces are T3 and Where z represents the polarization direction of the piezoelectric transducer, dz represents the displacement in the z direction, and if its cross-sectional area is B, the resultant force of the small segment can be expressed as:

[0091]

[0092] The mass of a small segment can be expressed as ρ c ·(Bdz) means that according to Newton's second law, the equation is as follows:

[0093]

[0094] Among them, ρ c is the density of PMNT material, ζ is the displacement of the end surface of PMNT material, t represents time, and the result is simplified as follows:

[0095]

[0096] Substituting the basic expression of T3, we get:

[0097]

[0098] Because of the boundary condition D = 0, So there is Among them, the speed of sound in piezoelectric materials, that is, the speed of sound of the constant electric displacement longitudinal wave, is

[0099] The piezoelectric film performs simple harmonic motion when working, so it satisfies Where w represents the angular frequency, which affects the speed and periodicity of simple harmonic motion. k represents the wave number of the piezoelectric material, so:

[0100]

[0101] This equation has a general solution: ζ=asinkz+bcoskz, where sin represents the sine function, cos represents the cosine function, a and b are constants, and the displacement of the two ends ζ| z＝0 =ζ1,ζ| z＝lc =-ζ2 Substituting into the general solution, we get:

[0102]

[0103] Therefore b=ζ1,

[0104] It can be deduced that:

[0105]

[0106] Simplified:

[0107]

[0108] The stress distribution of piezoelectric materials is determined by the basic piezoelectric equation, and the stress is balanced with the external force, that is:

[0109]

[0110] Where F1 and F2 represent the total forces at both ends of the piezoelectric material, K represents the cross-sectional area, and l c express

[0111] The thickness of the piezoelectric material, so the expression of the external force at both ends is:

[0112]

[0113] According to the piezoelectric equation: We can get: The two ends of the piezoelectric material are electrodes, the charge Q on the electrodes is Q = D3K, and the voltage V at the two ends of the electrodes is:

[0114]

[0115] Since the state equation of the circuit is: It can also be expressed as Where I represents current and j represents imaginary unit. Substituting into the equation:

[0116]

[0117] Then we have:

[0118]

[0119] in, and represents the vibration velocity at both ends of the piezoelectric material, C0 represents the cut-off capacitance of the piezoelectric material, and n represents the electromechanical coupling coefficient of the piezoelectric material; substituting it into the external force expression at both ends, we can get:

[0120]

[0121] Among them, ρ represents the density of piezoelectric material, c represents the speed of sound in piezoelectric material, tan represents the tangent function, and k represents the wave number of piezoelectric material.

[0122] When the piezoelectric transducer vibrates radially, its piezoelectric material will contract and expand alternately, generating the radiation of sound waves. At the same time, this vibration will also cause the radiated sound field to exert a reaction force on the piezoelectric transducer. This reaction force can be understood as the pressure generated when the radiated sound waves propagate to the surrounding medium, and then act on the vibrating surface of the piezoelectric transducer. This reaction force will affect the vibration characteristics of the transducer and may affect the performance and efficiency of the transducer. Therefore, when designing and applying piezoelectric transducers, it is necessary to consider the impact of this reaction force on the transducer to optimize its performance.

[0123] The reaction force F of the radiated sound field s It is expressed as:

[0124]

[0125] Among them, Z m represents the radiation impedance of the transducer over the length l, ξ represents the displacement of the sound source, R s and X s The radiation resistance and radiation reactance over the length of the transducer l are:

[0126]

[0127] Among them, m s represents the radiation quality of the transducer length l, ρ m and V m are the density and speed of sound of the medium during propagation, π represents the circumference of a circle, r represents the effective radius of the transducer, and κ m represents the acoustic wave number of the medium, J0 and J1 represent the zero-order and first-order Bessel functions, N0(κ m r) and N1(κ m r) denotes the zero-order and first-order Newman functions, and ω denotes the angular frequency.

[0128] The sound power of the sound wave radiated by the transducer into the medium is affected by the radiation resistance R s The radiated sound power P is expressed as:

[0129]

[0130] In this embodiment, when the radiation sound source level increases, it means that the sound energy level radiated by the transducer into the medium also increases; under the same radiation sound source level, reducing the input electric power can improve the energy utilization efficiency of the transducer, reduce the ineffective power generated by the device, and thus improve the electroacoustic conversion efficiency; the reduced mass indicates that the transducer is more suitable for installation on the carrier and is more convenient to use, so the objective function of the piezoelectric transducer model in step S2 is:

[0131] minF(x)={f1(x),f2(x),f3(x)}

[0132] Among them, min means minimization, F(x) represents the piezoelectric transducer model; f1(x) represents the maximization of the radiated sound source level; f2(x) represents the minimization of the input electric power; f3(x) represents the minimization of the mass;

[0133] When dealing with problems with larger sound source levels, it is necessary to find its opposite in advance and convert it into a minimization problem. Therefore, the objective function expression for maximizing the sound source level is:

[0134] f1(x)=-SL=-(10lg(P)+170.8)

[0135] Where SL represents the radiation source level, |P represents the sound source intensity, lg represents the logarithmic function with base 10, and lg(P) is used to describe the radiation characteristics of the sound source, which involves factors such as the geometric shape, wave mode or radiation efficiency of the sound source;

[0136] The objective function expression for minimizing input electric power is:

[0137]

[0138] Among them, P in represents input power, Z represents impedance, V rms Indicates the driving voltage;

[0139] The objective function expression of minimum quality is:

[0140] f3(x)=m

[0141] Here, m represents the mass.

[0142] In this embodiment, the constraints of the piezoelectric transducer model in step S2 include resonance frequency constraints, material parameter constraints, upper and lower limits of sound source level constraints, piezoelectric material thickness limit constraints, piezoelectric material minimum radial dimension constraints, depolarization field strength constraints, and transducer working power capacity constraints;

[0143] The expression formula of the resonant frequency constraint is:

[0144]

[0145] Among them, f s represents the resonant frequency, f low Indicates the lower limit of operating frequency, f up Indicates the upper limit of the operating frequency, l c represents the thickness of the piezoelectric material, represents the elastic modulus, σ Erepresents the Poisson's ratio of the piezoelectric material, which affects the strain and stiffness of the material in different directions, especially in three-dimensional stress states. It is used to adjust the elastic properties of the material and modify the elastic modulus while considering the Poisson effect, so as to more accurately describe the dynamic behavior of the material when subjected to different types of loads (such as axial and lateral loads). ρ represents the density of the piezoelectric material.

[0146] The material parameter constraint is expressed as:

[0147] mat=mat i ,i=1,2,...,q

[0148] Among them, mat represents the piezoelectric material property parameters, which is a 5×1-dimensional column vector. d 33 represents the piezoelectric constant, s represents the mechanical strain, ρ represents the density of the piezoelectric material, ε 33 represents the dielectric constant, σ E represents the Poisson's ratio of the piezoelectric material, q represents the total number of piezoelectric material types, mat i represents the property parameters of the i-th piezoelectric material, mat i ∈A, A represents the piezoelectric material property matrix composed of q kinds of piezoelectric materials, A={mat1mat2…mat q};

[0149] The expression formula of the upper and lower limit constraints of the sound source level is:

[0150]

[0151] in, Indicates the lower limit of the sound source level, Indicates the upper limit of the sound source level, SL1 indicates the lower limit of the sound source level, and SL2 indicates the upper limit of the sound source level;

[0152] The expression formula of the piezoelectric material thickness limit constraint is:

[0153] l c ≥L0

[0154] Wherein, L0 represents the thickness limit value;

[0155] The expression formula of the minimum radial dimension constraint of the piezoelectric material is:

[0156] r≥R0

[0157] Where r represents the minimum radial dimension of the piezoelectric material, and R0 represents the radius limit of the actual process;

[0158] When the piezoelectric ceramic material is under the action of an electric field and its polarization direction is opposite to the direction of the electric field, the originally directional electric dipole moment gradually loses its order, resulting in a weakening of the polarization strength of the material. Therefore, the expression formula of the depolarization field strength constraint is:

[0159]

[0160] Among them, V rms represents the driving voltage, and E0 represents the reference electric field, which is used to compare the response of piezoelectric materials under different polarization states. In the absence of an external electric field, the reference electric field E0 is the initial electric field strength caused by spontaneous polarization or other factors inside the piezoelectric material;

[0161] The transducer will experience power fatigue when working under alternating stress, so the expression formula of the transducer working power capacity constraint is:

[0162]

[0163] Where P represents the radiated sound power, P M represents the power fatigue limit, π represents the circumference of a circle, f0 represents the resonant frequency of the transducer, which is the natural vibration frequency of the transducer under undamped conditions and is an important parameter affecting the performance of the transducer, V represents the voltage across the piezoelectric material, T0 represents the tensile strength, S represents the area of ​​the transducer, and Q M Expressing the mechanical quality factor, we have:

[0164] Q m =1 / 4π(C0+C1)R1Δf

[0165] Wherein, C0 represents the static capacitance of the piezoelectric material, C1 represents the dynamic capacitance of the piezoelectric material, R1 represents the equivalent resistance at resonance, and Δf represents the difference between the resonant frequency and the anti-resonant frequency.

[0166] In this embodiment, the hybrid decision vector of the piezoelectric transducer model in step S2 is:

[0167] x T ={mat T ,r,l c ,V rms ,f low ,f up} T

[0168] Among them, x T represents the transpose of the hybrid decision vector of the piezoelectric transducer model, r represents the minimum radial size of the piezoelectric material, l c Represents the single crystal thickness, V rms represents the driving voltage, f low Indicates the lower limit of operating frequency, fup Indicates the upper limit of the operating frequency, mat T The transpose of the piezoelectric material property parameter mat is:

[0169]

[0170] Among them, d 33 It represents the piezoelectric constant, which is the mechanical strain of the piezoelectric material in the same direction (along the z direction) when an electric field is applied (z represents the polarization direction of the piezoelectric transducer, i.e., along the z direction). The unit is (pC / N) or (m / V). The piezoelectric constant d 33 The larger the value, the stronger the piezoelectric effect of the material; s represents mechanical strain, which usually refers to the relative deformation of the material under the action of external force or electric field, and is used to describe the degree of deformation of the material when an electric field or mechanical force is applied; ρ represents the density of the piezoelectric material, and ε 33 It represents the dielectric constant, which indicates the capacitive properties of the material in the direction of the electric field when an electric field is applied. It describes the polarization ability of the material under the application of an electric field. The unit is (F / m). The dielectric constant ε 33 The larger the value, the stronger the polarization ability of the material under the action of the electric field. E represents the Poisson's ratio of the piezoelectric material.

[0171] In this embodiment, step S3 specifically includes the following steps:

[0172] S31. Initialize the operating parameters of the NSGA-Ⅱ multi-objective optimization algorithm and randomly generate an initial population P of size N according to the objective function of the piezoelectric transducer model. k , the initial value of the population generation k is 0, and P k As the parent population, the initial population P k Design parameters for the transducer to be optimized;

[0173] S32. For the parent population P k The selection operation, simulated binary crossover operation and polynomial mutation operation are performed in sequence to obtain the offspring population D k ;

[0174] S33. According to the elite selection strategy (non-dominated sorting and crowding distance sorting) and the constraints of the piezoelectric transducer model, from the parent population P k and D in the progeny population k Select elite individuals that meet the constraints, use the elite individuals as the parent population in the next generation genetic algorithm, and increase the generation number k of the population by 1, and execute step S34;

[0175] S34. Determine whether the number of evolution times has reached the maximum value. If not, return to step S32; if reached, end the operation and take the last generation of population as the optimal solution, that is, the optimal transducer design parameters, to complete the multi-objective intelligent optimization design of the piezoelectric transducer.

[0176] In this embodiment, the optimal solution in step S34 is expressed as:

[0177] PF*={F(x*)= { f1(x*),f2(x*),f3(x*) } x*∈P*}

[0178] Among them, PF* represents the optimal solution, F(x * ) represents the optimal solution of the piezoelectric transducer model, f1(x * ) represents the optimal solution for maximizing the radiation sound source level, f2(x * ) represents the optimal solution for minimizing the input power, f3(x * ) represents the optimal solution for minimizing mass, x * The optimal solution of the hybrid decision vector representing the piezoelectric transducer model, P * represents the optimal solution space of the design parameter space, that is, in multi-objective optimization, P * It refers to the optimal solution set that meets multiple design objectives and constraints, that is, the optimal set of transducer design parameters, involving considerations of performance, efficiency, cost, stability, etc.

[0179] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. A multi-objective intelligent optimization design method for a piezoelectric transducer, characterized in that: The method comprises the following steps: S1. Collecting performance data of the piezoelectric transducer and performing data cleaning on the performance data; S2. Establishing a piezoelectric transducer model using the processed data; S3. Use the NSGA-Ⅱ multi-objective optimization algorithm to calculate the piezoelectric transducer model, obtain the optimal transducer design parameters, and complete the multi-objective intelligent optimization design of the piezoelectric transducer.

2. The multi-objective intelligent optimization design method for piezoelectric transducer according to claim 1 is characterized in that: The performance data in step S1 include voltage-displacement curve, frequency response curve, sound pressure level curve, electroacoustic conversion efficiency, characteristic parameters of piezoelectric materials, temperature characteristics, durability test data and environmental factors.

3. The multi-objective intelligent optimization design method for piezoelectric transducer according to claim 1 is characterized in that: The step S1 specifically includes the following sub-steps: S11. Collect performance data of piezoelectric transducers using sensors and graphical programming tools; S12. Based on a graphical programming tool, a relational database is constructed, and the performance data and material property data of the piezoelectric transducer collected by the sensor are stored in the relational database; S13. Perform data cleaning on the performance data and material property data of the piezoelectric transducer in the relational database.

4. The multi-objective intelligent optimization design method for piezoelectric transducer according to claim 3 is characterized in that: The data cleaning in step S13 includes removing duplicate data, processing missing values, and verifying the integrity and consistency of the data.

5. The multi-objective intelligent optimization design method for piezoelectric transducer according to claim 1, characterized in that: The objective function of the piezoelectric transducer model in step S2 is: minF(x)={f1(x),f2(x),f3(x)} Among them, min means minimization, F(x) represents the piezoelectric transducer model; f1(x) represents the maximization of the radiated sound source level; f2(x) represents the minimization of the input electric power; f3(x) represents the minimization of the mass, and we have: Where SL represents the radiation sound source level, |P represents the sound source intensity, lg represents the logarithmic function with base 10, and P in represents input power, Z represents impedance, V rms represents the driving voltage and m represents the mass.

6. The multi-objective intelligent optimization design method for piezoelectric transducers according to claim 5, characterized in that: The constraints of the piezoelectric transducer model in step S2 include resonance frequency constraints, material parameter constraints, upper and lower limits of sound source level constraints, piezoelectric material thickness limit constraints, piezoelectric material minimum radial dimension constraints, depolarization field strength constraints, and transducer working power capacity constraints; The expression formula of the resonant frequency constraint is: Among them, f s represents the resonant frequency, f low Indicates the lower limit of operating frequency, f up Indicates the upper limit of the operating frequency, l c represents the thickness of the piezoelectric material, represents the elastic modulus, σ E represents the Poisson's ratio of the piezoelectric material, and ρ represents the density of the piezoelectric material; The material parameter constraint is expressed as follows: mat=mat i ,i=1,2,...,q Among them, mat represents the piezoelectric material property parameters, q represents the total number of piezoelectric material types, mat i represents the property parameters of the i-th piezoelectric material; The expression formula of the upper and lower limit constraints of the sound source level is: in, Indicates the lower limit of the sound source level, Indicates the upper limit of the sound source level, SL1 indicates the lower limit of the sound source level, and SL2 indicates the upper limit of the sound source level; The expression formula of the piezoelectric material thickness limit constraint is: l c ≥L0 Wherein, L0 represents the thickness limit value; The expression formula of the minimum radial dimension constraint of the piezoelectric material is: r≥R0 Where r represents the minimum radial dimension of the piezoelectric material, and R0 represents the radius limit of the actual process; The expression formula of the depolarization field strength constraint is: Among them, V rms represents the driving voltage, E0 represents the reference electric field; The expression formula of the transducer working power capacity constraint is: Where P represents the radiated sound power, P M represents the power fatigue limit, π represents the circumference, f0 represents the resonant frequency of the transducer, V represents the voltage across the piezoelectric material, T0 represents the tensile strength, S represents the area of ​​the transducer, Q M Expressing the mechanical quality factor, we have: Q m =1 / 4π(C0+C1)R1Δf Wherein, C0 represents the static capacitance of the piezoelectric material, C1 represents the dynamic capacitance of the piezoelectric material, R1 represents the equivalent resistance at resonance, and Δf represents the difference between the resonant frequency and the anti-resonant frequency.

7. The multi-objective intelligent optimization design method for piezoelectric transducers according to claim 6, characterized in that: The hybrid decision vector of the piezoelectric transducer model in step S2 is: x T ={mat T ,r,l c ,V rms ,f low ,f up } T Among them, x T represents the transpose of the hybrid decision vector of the piezoelectric transducer model, r represents the minimum radial size of the piezoelectric material, l c Represents the single crystal thickness, V rms represents the driving voltage, f low Indicates the lower limit of operating frequency, f up Indicates the upper limit of the operating frequency, mat T The transpose of the piezoelectric material property parameter mat is: Among them, d 33 represents the piezoelectric constant, s represents the mechanical strain, ρ represents the density of the piezoelectric material, ε 33 represents the dielectric constant, σ E represents the Poisson's ratio of the piezoelectric material.

8. The multi-objective intelligent optimization design method for piezoelectric transducer according to claim 7, characterized in that: The step S3 specifically comprises the following steps: S31. Initialize the operating parameters of the NSGA-Ⅱ multi-objective optimization algorithm and randomly generate an initial population P of size N according to the objective function of the piezoelectric transducer model. k , the initial value of the population generation k is 0, and P k As the parent population, the initial population P k Design parameters for the transducer to be optimized; S32. For the parent population P k The selection operation, simulated binary crossover operation and polynomial mutation operation are performed in sequence to obtain the offspring population D k ; S33. According to the elite selection strategy and the constraints of the piezoelectric transducer model, from the parent population P k and D in the progeny population k Select elite individuals that meet the constraints, use the elite individuals as the parent population in the next generation genetic algorithm, and increase the generation number k of the population by 1, and execute step S34; S34. Determine whether the number of evolution times has reached the maximum value. If not, return to step S32; if reached, end the operation and take the last generation of population as the optimal solution, that is, the optimal transducer design parameters, to complete the multi-objective intelligent optimization design of the piezoelectric transducer.

9. The multi-objective intelligent optimization design method for piezoelectric transducer according to claim 8, characterized in that: The optimal solution in step S34 is expressed as: PF*={F(x*)= { f1(x*),f2(x*),f3(x*) } x*∈P*} Among them, PF* represents the optimal solution, F(x * ) represents the optimal solution of the piezoelectric transducer model, f1(x * ) represents the optimal solution for maximizing the radiation sound source level, f2(x * ) represents the optimal solution for minimizing the input power, f3(x * ) represents the optimal solution for minimizing mass, x * The optimal solution of the hybrid decision vector representing the piezoelectric transducer model, P * It represents the optimization solution space of the design parameter space, that is, the optimal set of transducer design parameters.

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