阅读说明：本技术 一种压电声学超材料的主动调控方法 (Active regulation and control method for piezoelectric acoustic metamaterial ) 是由 唐炜 陈振伟 兰嘉琪 于 2021-08-20 设计创作，主要内容包括：本发明公开了一种压电声学超材料的主动调控方法,具体为：针对有限长度和有限数量局域谐振单元的一维压电声学超材料,首先建立机电耦合模型,之后在压电声学超材料产生负动态刚度的前提下,计算压电声学超材料的带隙范围和形成条件,然后推导出传递函数并进行频率补偿,最后将传递函数数字化,实现了数字可编程压电声学超材料；本发明所提出的主动调控方法可以实时地、方便地根据目标频率进行参数配置,在低频范围内实现了明显的带隙和超过40dB的超强振动衰减；并且,压电声学超材料是一个多输入多输出(MIMO)系统,本发明提出的主动调控方法极大降低了MIMO系统的设计复杂度,为主动控制算法在压电声学超材料中的大规模应用搭建了桥梁。(The invention discloses an active regulation and control method of a piezoelectric acoustic metamaterial, which comprises the following steps: aiming at the one-dimensional piezoelectric acoustic metamaterial with limited length and limited number of local resonance units, firstly establishing an electromechanical coupling model, then calculating the band gap range and forming conditions of the piezoelectric acoustic metamaterial on the premise that the piezoelectric acoustic metamaterial generates negative dynamic stiffness, then deducing a transfer function and carrying out frequency compensation, and finally digitizing the transfer function to realize the digital programmable piezoelectric acoustic metamaterial; the active regulation and control method provided by the invention can be used for conveniently configuring parameters according to target frequency in real time, and realizing obvious band gap and super-strong vibration attenuation exceeding 40dB in a low-frequency range; in addition, the piezoelectric acoustic metamaterial is a multiple-input multiple-output (MIMO) system, the active regulation and control method provided by the invention greatly reduces the design complexity of the MIMO system, and a bridge is built for the large-scale application of an active control algorithm in the piezoelectric acoustic metamaterial.)

1. An active regulation and control method of a piezoelectric acoustic metamaterial is characterized by comprising the following steps:

s1, establishing an electromechanical coupling model of the piezoelectric acoustic metamaterial;

s2, calculating the band gap range and the forming condition of the piezoelectric acoustic metamaterial on the premise that the piezoelectric acoustic metamaterial generates negative dynamic stiffness according to the electromechanical coupling model of S1;

s3, according to the electromechanical coupling model of S1, a transfer function is deduced, the resonant frequency is compensated, and a band gap with adjustable range and depth can be formed on the premise of meeting the band gap forming condition of S2;

and S4, digitizing the transfer function of S3, and realizing the active regulation and control of the piezoelectric acoustic metamaterial.

2. The active regulating method of a piezoelectric acoustic metamaterial according to claim 1, wherein an electromechanical coupling model of the piezoelectric acoustic metamaterial is established in S1, specifically:

according to the control unit, an electromechanical coupling model of the piezoelectric acoustic metamaterial is established by utilizing a dynamic equation of the composite beam structure, wherein the electromechanical coupling equation of the metamaterial structure is subjected to decoupling processing, and the order r modal response can be expressed as:

in the formula, H_r(s) is Laplace transform of the modal coordinates corresponding to the r-th order mode, Q_r(s) is the Laplace transform of the modal excitation force of the composite beam structure, s is the Laplace operator, ζ_rIs the mechanical damping ratio, omega, corresponding to the r-th order mode of the composite beam structure_rIs the r-th order natural frequency of the composite beam structure, alpha is a dimensionless parameter related to electromechanical coupling, C_pIs the internal equivalent capacitance of the piezoelectric sheet, beta is the voltage amplification factor of the voltage amplification circuit;

Z₀(s) ═ 1/(Cs), z(s) ═ Ls + R, where C is the feedback capacitance of the charge amplifier, and L, R are the inductance and resistance, respectively, in series with the piezoelectric patches in the enhanced shunting circuit.

3. The active regulation and control method of a piezoelectric acoustic metamaterial according to claim 2, wherein in S2, based on the electromechanical coupling model, on the premise that the piezoelectric acoustic metamaterial generates negative dynamic stiffness, the band gap range and the formation condition of the piezoelectric acoustic metamaterial are calculated, specifically:

the band gap ranges are:

band gap formation conditions:

in the above formula, ω_tThe resonant frequency of the inductor-resistor series shunt circuit is satisfied_t ²＝1/(LC_p)。

4. The active control method of a piezoelectric acoustic metamaterial according to claim 3, wherein in S3, a transfer function is derived according to an electromechanical coupling model, specifically:

s31, obtaining a general form of the transfer function according to the control unit as:

in the above equation, γ is an additional gain of the control output.

S32, according to band gap range and forming condition, for resonance frequency omega in S31_tAnd (3) carrying out frequency compensation:

ω_t＝ω_c+Δω_c

in the above formula,. DELTA.omega_cIs compensating for the frequency, ω_cIs the center frequency of the band gap.

5. The active regulation and control method of a piezoelectric acoustic metamaterial according to claim 4, wherein in the step S4, the transfer function is digitized to realize active regulation and control of the piezoelectric acoustic metamaterial, and specifically, the method comprises the following steps:

firstly, a transfer function is discretized by using a zero-order retainer according to sampling time, then the discretized second-order transfer function is converted into a form of a difference equation and is input into a digital controller, and active regulation and control of the piezoelectric acoustic metamaterial are achieved.

6. The active regulation method of a piezoelectric acoustic metamaterial according to any one of claims 2 to 5, wherein the control unit includes a pair of piezoelectric elements and an enhanced shunt circuit, and the pair of piezoelectric elements and the enhanced shunt circuit are connected.

7. The active regulation and control method of a piezoelectric acoustic metamaterial according to claim 6, wherein the enhanced shunt circuit comprises a charge amplification circuit, a voltage amplification circuit, a resistor and an inductor which are arranged in series, one of the pair of piezoelectric elements is connected with the charge amplification circuit, and the other piezoelectric element forms a piezoelectric actuator by utilizing an inverse piezoelectric effect.

Technical Field

The invention belongs to the technical field of vibration control, and particularly relates to an active regulation and control method of a piezoelectric acoustic metamaterial.

Background

The piezoelectric acoustic metamaterial is formed by attaching a piezoelectric material in a controlled structure in an embedding or sticking mode and the like, connecting the piezoelectric material with a shunt circuit to form a local resonance unit, and forming a periodic structure by the local resonance unit; the piezoelectric acoustic metamaterial has wide application prospect in the field of vibration and noise reduction due to the advantages of light weight, flexibility, high design freedom degree and the like.

The local resonance unit of the periodic structure has elastic wave band gap characteristics, and under the action of the band gap, the propagation of elastic waves in the structure is hindered; the traditional shunt circuit is realized based on analog electronic devices, for example, a piezoelectric plate is connected with an LR shunt circuit to generate local resonance, so that a tunable vibration absorber is realized; in order to enhance the local resonant band gap caused by the passive resonant shunt circuit, an enhanced shunt circuit (a-R circuit) is proposed, but the piezoelectric acoustic metamaterial formed by the analog shunt circuit is difficult to tune in real time, and the control effect at a low frequency is poor.

In order to solve the limitation of an analog shunt circuit, a digital impedance technology is provided, a microcontroller is used for realizing a synthesized impedance circuit, the required impedance can be established between the voltage on a piezoelectric element and the current flowing out, the existing digital controller realized based on an AR circuit adopts a zero-pole method to adjust the pole and the zero in a Young modulus transfer function, the negative dynamic stiffness is not directly considered, the parameter configuration is not accurate, the formation of the piezoelectric acoustic metamaterial band gap depends on whether the negative dynamic stiffness can be generated, the dynamic stiffness of a system can be influenced by changing the parameters of the shunt circuit, and the flexible adjustment of the local resonance band gap is realized.

Disclosure of Invention

According to the active regulation and control method for the piezoelectric acoustic metamaterial, provided by the invention, the negative dynamic stiffness is taken as an important parameter to realize final regulation and control, so that the regulation of the local resonance band gap is more flexible and accurate.

The technical scheme adopted by the invention is as follows:

an active regulation and control method of a piezoelectric acoustic metamaterial is implemented according to the following steps:

s1, establishing an electromechanical coupling model of the piezoelectric acoustic metamaterial;

s2, calculating the band gap range and the forming condition of the piezoelectric acoustic metamaterial on the premise that the piezoelectric acoustic metamaterial generates negative dynamic stiffness according to the electromechanical coupling model of S1;

s3, deriving a transfer function of a control unit according to the electromechanical coupling model of S1, compensating the resonant frequency, and forming a band gap with adjustable range and depth on the premise of meeting the band gap forming condition of S2;

and S4, digitizing the transfer function of S3, and realizing the active regulation and control of the piezoelectric acoustic metamaterial.

Preferably, the establishing an electromechanical coupling model of the piezoelectric acoustic metamaterial in S1 specifically includes:

according to the control unit, an electromechanical coupling model of the piezoelectric acoustic metamaterial is established by utilizing a dynamic equation of the composite beam structure, wherein the electromechanical coupling equation of the metamaterial structure is subjected to decoupling processing, and the order r modal response can be expressed as:

in the formula, H_r(s) is Laplace transform of the modal coordinates corresponding to the r-th order mode, Q_r(s) is the Laplace transform of the modal excitation force of the composite beam structure, s is the Laplace operator, ζ_rIs the mechanical damping ratio, omega, corresponding to the r-th order mode of the composite beam structure_rIs the r-th order natural frequency of the composite beam structure, alpha is a dimensionless parameter related to electromechanical coupling, C_pIs the internal equivalent capacitance of the piezoelectric sheet, beta is the voltage amplification factor of the voltage amplification circuit;

Z₀(s) ═ 1/(Cs), z(s) ═ Ls + R, where C is the feedback capacitance of the charge amplifier, and L, R are the inductance and resistance, respectively, in series with the piezoelectric patches in the enhanced shunting circuit.

Preferably, in S2, the band gap range and the forming condition of the piezoelectric acoustic metamaterial are calculated according to the condition that the electromechanical coupling model generates negative dynamic stiffness in the piezoelectric acoustic metamaterial, specifically:

the band gap ranges are:

band gap formation conditions:

in the above formula, ω_tThe resonant frequency of the inductor-resistor series shunt circuit is satisfied_t ²＝1/(LC_p)。

Preferably, in S3, the transfer function is derived and the resonant frequency is compensated according to the electromechanical coupling model, specifically:

s31, obtaining a general form of the transfer function according to the control unit as:

in the above equation, γ is an additional gain of the control output.

S32, according to band gap range and forming condition, for resonance frequency omega in S31_tAnd (3) carrying out frequency compensation:

ω_t＝ω_c+Δω_c

in the above formula,. DELTA.omega_cIs compensating for the frequency, ω_cIs the center frequency of the band gap.

Preferably, in S4, the transfer function is digitized to realize active control of the piezoelectric acoustic metamaterial, specifically:

firstly, a transfer function is discretized by using a zero-order retainer according to sampling time, then the discretized second-order transfer function is converted into a form of a difference equation and is input into a digital controller, and active regulation and control of the piezoelectric acoustic metamaterial are achieved.

Preferably, the control unit includes a pair of piezoelectric elements and an enhanced shunt circuit, and the pair of piezoelectric elements and the enhanced shunt circuit are connected.

Preferably, the enhancement type shunt circuit includes a charge amplifying circuit, a voltage amplifying circuit, a resistor, and an inductor, which are arranged in series, one of the pair of piezoelectric elements is connected to the charge amplifying circuit, and the other piezoelectric element forms a piezoelectric actuator by using an inverse piezoelectric effect.

Compared with the prior art, the active regulation and control method of the piezoelectric acoustic metamaterial provided by the invention is used for the one-dimensional piezoelectric acoustic metamaterial with limited length and limited number of local resonance units, firstly, an electromechanical coupling model is established, then, on the premise that the piezoelectric acoustic metamaterial generates negative dynamic stiffness, the band gap range and the forming condition of the piezoelectric acoustic metamaterial are calculated, then, a transfer function is deduced and frequency compensation is carried out, and finally, the transfer function is digitized, so that the digital programmable piezoelectric acoustic metamaterial is realized.

The active regulation and control method provided by the invention can be used for conveniently configuring parameters according to target frequency in real time, and realizing obvious band gap and super-strong vibration attenuation exceeding 40dB in a low-frequency range; in addition, the piezoelectric acoustic metamaterial is a multiple-input multiple-output (MIMO) system, and the design complexity of the MIMO system is greatly reduced by the active regulation and control method provided by the invention.

Drawings

FIG. 1 is a flowchart of an active control method for a piezoelectric acoustic metamaterial according to an embodiment of the present invention;

fig. 2 is a schematic diagram of an enhanced shunt circuit local resonance unit circuit in an active regulation method for a piezoelectric acoustic metamaterial according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a control unit of an active regulation and control method for a piezoelectric acoustic metamaterial according to an embodiment of the present invention;

fig. 4 is a frequency response characteristic diagram of an active regulation method for a piezoelectric acoustic metamaterial according to an embodiment of the present invention.

Reference is made to the accompanying drawings in which: the circuit comprises a 1-enhanced shunt circuit, a 2-charge amplification circuit and a 3-voltage amplification circuit.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the description of the present invention, it is to be understood that the terms "vertical", "lateral", "longitudinal", "front", "rear", "left", "right", "upper", "lower", "horizontal", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description of the present invention, and do not mean that the device or member to which the present invention is directed must have a specific orientation or position, and thus, cannot be construed as limiting the present invention.

The following description provides embodiments of the invention, which may be combined with or substituted for various embodiments, and the invention is thus to be construed as embracing all possible combinations of the same and/or different embodiments described. Thus, if one embodiment includes feature A, B, C and another embodiment includes feature B, D, then this application should also be considered to include an embodiment of A, B, C, D in all other possible combinations, although this embodiment may not be explicitly recited in the following text.

The embodiment of the invention provides an active regulation and control method of a piezoelectric acoustic metamaterial, which is implemented according to the following steps as shown in figure 1:

s1, establishing an electromechanical coupling model of the piezoelectric acoustic metamaterial;

s2, calculating the band gap range and the forming condition of the piezoelectric acoustic metamaterial on the premise that the piezoelectric acoustic metamaterial generates negative dynamic stiffness according to the electromechanical coupling model of S1;

s3, according to the electromechanical coupling model of S1, a transfer function is deduced, the resonant frequency is compensated, and a band gap with adjustable range and depth can be formed on the premise of meeting the band gap forming condition of S2;

and S4, digitizing the transfer function of S3, and realizing the active regulation and control of the piezoelectric acoustic metamaterial.

Thus, by adopting the method, the embodiment firstly establishes an electromechanical coupling model for the one-dimensional piezoelectric acoustic metamaterial with limited length and limited number of local resonance units, then calculates the band gap range and formation conditions of the piezoelectric acoustic metamaterial on the premise that the piezoelectric acoustic metamaterial generates negative dynamic stiffness, then deduces a transfer function and compensates the resonant frequency, and finally digitizes the transfer function, thereby realizing the digital programmable piezoelectric acoustic metamaterial.

The active regulation and control method provided by the invention can be used for conveniently configuring parameters in real time according to the target frequency, and realizing obvious band gap and non-traditional super-strong vibration attenuation exceeding 40dB in a low-frequency range; in addition, the piezoelectric acoustic metamaterial is a multiple-input multiple-output (MIMO) system, the active regulation and control method provided by the embodiment greatly reduces the design complexity of the MIMO system, and a bridge is built for the large-scale application of an active control algorithm in the piezoelectric acoustic metamaterial.

In a specific embodiment:

establishing an electromechanical coupling model of the piezoelectric acoustic metamaterial in the step S1, specifically:

according to the control unit, obtaining a kinetic equation of the composite beam structure under the action of external input voltage:

wherein EI is flexural rigidity of the composite beam structure under the condition of short circuit of the piezoelectric element, w (x, t) is transverse deflection of the beam at the position x and the time t, m is mass of the composite beam structure in unit length, theta is electromechanical coupling term under physical coordinates, and v is_j(t) is the potential difference between the electrodes of the jth pair of piezoelectric elements, numbered j 1,2_j ^LStart, to x_j ^REnd, total length Δ x_j＝x_j ^R-x_j ^LH(s) is the Heaviside function and f (x, t) is the transverse force per unit length distributed over the composite beam.

The transverse deflection of the composite beam structure is expanded in a modal space, and the front N-order vibration mode is intercepted, so that the method comprises the following steps:

wherein the number of the mode is r ═ 1,2_r(t) is a modal coordinate expression corresponding to the nth order mode, phi_r(x) Is the quality normalization eigenfunction of the mode shape corresponding to the r-th order mode.

The unit length transverse force f (x, t) distributed on the composite beam is equivalently replaced by concentrated force, so that the vibration problem is simplified, and the composite beam structure is obtained when x is x_fModal excitation force q of_r(t)：

Establishing an electromechanical coupling model of the piezoelectric acoustic metamaterial, wherein an electromechanical coupling equation of a metamaterial structure is subjected to decoupling processing, and the order r modal response can be expressed as:

in the formula, H_r(s) is Laplace transform of the modal coordinates corresponding to the r-th order mode, Q_r(s) is the Laplace transform of the modal excitation force of the composite beam structure, s is the Laplace operator, ζ_rIs the mechanical damping ratio, omega, corresponding to the r-th order mode of the composite beam structure_rIs the r-th order natural frequency of the composite beam structure, alpha is a dimensionless parameter related to electromechanical coupling, C_pIs the internal equivalent capacitance of the piezoelectric sheet, beta is the voltage amplification factor of the voltage amplification circuit;

Z₀(s)＝1/(Cs)，Z(s)＝Ls + R, where C is the feedback capacitance of the charge amplifier, and L, R is the inductance and resistance, respectively, in the enhanced shunting circuit in series with the piezoelectric patch.

More specifically:

the control unit comprises a pair of piezoelectric elements and an enhanced shunt circuit, and the pair of piezoelectric elements is connected with the enhanced shunt circuit.

The enhanced shunt circuit 1 comprises a charge amplifying circuit 2, a voltage amplifying circuit 3, a resistor and an inductor which are arranged in series, wherein one piezoelectric element in a pair of piezoelectric elements is connected with the charge amplifying circuit, and the other piezoelectric element forms a piezoelectric actuator by utilizing the inverse piezoelectric effect.

A pair of piezoelectric elements and an enhanced shunt circuit jointly form a local resonance unit, as shown in fig. 2, the local resonance unit is an enhanced shunt circuit local resonance unit circuit schematic diagram, the local resonance unit includes a pair of piezoelectric elements and an enhanced shunt circuit, one of the pair of piezoelectric elements is connected with a charge amplification circuit and acts as a piezoelectric sensor, the other piezoelectric element forms a piezoelectric actuator by utilizing inverse piezoelectric effect, and each piezoelectric element can be represented as a current source connected in parallel with an internal capacitor thereof.

The enhanced shunt circuit 1 is composed of a charge amplifying circuit 2, a voltage amplifying circuit 3 and an inductive resistor series circuit, the whole framework composed of the enhanced shunt circuit and a piezoelectric element can be regarded as a typical active control system, and the resonance principle is a main control strategy.

In a specific embodiment:

the piezoelectric elements were selected according to the parameters of table 1 below:

TABLE 1

In a specific embodiment:

the composite beam structure base material selects stainless steel, eight pairs of piezoelectric patches are closely attached to the upper surface and the lower surface of the base beam, the distances between the piezoelectric patches are the same, and the piezoelectric patches are symmetrically distributed on the symmetrical axis in the length direction of the composite beam structure. PZT-5H is selected as the piezoelectric patch, the polarization directions of the piezoelectric elements attached in pairs are opposite, and the size and the structural parameters of the matrix beam are shown in table 2:

TABLE 2

In the step S2, calculating a band gap range and a forming condition of the piezoelectric acoustic metamaterial according to the negative dynamic stiffness generated by the electromechanical coupling model and the piezoelectric acoustic metamaterial, specifically:

the band gap ranges are:

band gap formation conditions:

in the above formula, ω_tThe resonant frequency of the inductor-resistor series shunt circuit is satisfied_t ²＝1/(LC_p)。

According to the band gap range, the forming conditions and the parameter comparison experiment, the larger the values of alpha and beta are, the larger the width and the depth of the band gap formed by the piezoelectric acoustic metamaterial are increased; the larger the R is, the width and the depth of the band gap are gradually reduced, and when the R value is too large, the band gap does not exist in the piezoelectric metamaterial.

Specifically, let

Substituting s-j omega into the above formula, in the frequency domain range

ω′_r ²＝a_r(ω)+b_r(ω)j

Wherein

If a is_r(ω)<0, then ω'_r ²The real part of the piezoelectric acoustic metamaterial is smaller than zero, which can be regarded as that the piezoelectric acoustic metamaterial realizes equivalent negative dynamic stiffness under the r-th mode, and the frequency range where omega is located is the band gap range. At the same time b_rAnd the (omega) is always larger than zero, and the action of the (omega) can be understood as that the piezoelectric acoustic metamaterial increases equivalent damping. Therefore, the enhanced shunt circuit achieves vibration suppression through the combined action of equivalent negative dynamic stiffness and equivalent damping.

In one embodiment:

in S3, a transfer function is derived and the resonant frequency is compensated according to the band gap range and the forming condition, specifically:

s31, obtaining a general form of the transfer function according to the control unit as:

in the above equation, γ is an additional gain of the control output.

Fig. 3 is a schematic diagram of a digital programmable piezoelectric acoustic metamaterial control unit, where the digital programmable piezoelectric acoustic metamaterial is composed of a plurality of piezoelectric metamaterial control units distributed periodically, and each control unit is the same. The digital programmable piezoelectric acoustic metamaterial is obtained by carrying out digital equivalence on the circuit principle of the enhanced shunt circuit, wherein the general form of the transfer function of the control unit is as shown above;

s32, according to band gap range and forming condition, for resonance frequency omega in S31_tAnd (3) carrying out frequency compensation:

ω_t＝ω_c+Δω_c

in the above formula,. DELTA.omega_cIs compensating for the frequency, ω_cIs the center frequency of the band gap.

In active regulation with a transfer function, given a target frequency, the center frequency of the desired bandgap coincides with the target frequency, but the center frequency of the local resonant bandgap formed by the digital circuit is lower than the target frequency, so the resonant frequency ω in the transfer function must be adjusted_tCompensation is performed. According to a transfer function, C_pAnd C, the additional gain gamma of the regulation control output is substantially equivalent to the electromechanical coupling strength alpha, and the gamma, the beta and the R are regulated, so that the regulation on the width and the depth of the band gap is realized. It should be noted that after the control system reaches dynamic equilibrium, the control output voltage of the digital controller cannot be increased again by increasing γ and β, which has no effect on performance enhancement and can lead to system divergence.

In one embodiment:

in the step S4, the transfer function is digitized to realize active control of the piezoelectric acoustic metamaterial, specifically:

firstly, a transfer function is discretized by using a zero-order retainer according to sampling time, then the discretized second-order transfer function is converted into a form of a difference equation and is input into a digital controller, and active regulation and control of the piezoelectric acoustic metamaterial are achieved.

Specifically, the method comprises the following steps:

the charge signal can be converted into a voltage signal suitable for the ADC acquisition range through a proper charge amplifying circuit, and the logic of the controller is completely realized by utilizing an embedded program. The program logic calculation process is completed in real time inside the microcontroller. The transfer function is digitized through a microcontroller, firstly, a continuous time transfer function is discretized by using a zero-order retainer according to sampling time, then, the discretized second-order transfer function is converted into a form of a difference equation, and finally, digitization is realized through a corresponding filter structure:

y(k)＝a₀x(k)+a₁x(k-1)+a₂x(k-2)-b₁y(k-1)-b₂y(k-2)

wherein x (k) is an input signal at time k, y (k) is an output signal at time k, a₀，a₁，a₂Is the feedforward filter coefficient, b₁，b₂Are the feedback filter coefficients.

In the present embodiment, the sampling frequency is 10 kHz.

Under the condition that all piezoelectric elements are grounded to realize short circuit, a frequency sweep experiment is carried out on the piezoelectric acoustic metamaterial, a frequency sweep signal is provided by a signal generator, the frequency is linearly changed from 5Hz to 200Hz, a data acquisition device acquires the excitation voltage output by the signal generator as system input, acquires the voltage signal output by an accelerometer as system output, and the amplitude-frequency characteristic of the system can be obtained by utilizing a signal processing method according to the input and output data as shown in FIG. 4. The natural frequency 105.6Hz is selected as the target frequency of the digital programmable piezoelectric acoustic metamaterial, and a vibration control experiment is carried out nearby the natural frequency, so that the metamaterial can generate an obvious band gap, and the remarkable vibration attenuation exceeding 40dB is achieved.

The digital controller can adjust the parameters wirelessly and in real time, thereby easily controlling the frequency, width and depth of the band gap. The active regulation and control method provided by the invention greatly reduces the design complexity of the MIMO system and builds a bridge for the large-scale application of the active control algorithm in the piezoelectric acoustic metamaterial.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.