Active regulation and control method of piezoelectric acoustic metamaterial

Abstract

The invention discloses an active regulation and control method for a piezoelectric acoustic metamaterial, and the method specifically comprises the steps: firstly building an electromechanical coupling model for a one-dimensional piezoelectric acoustic metamaterial with a limited length and a limited number of local resonance units, and then calculating the band gap range and formation conditions of the piezoelectric acoustic metamaterial on the premise that the piezoelectric acoustic metamaterial generates the negative dynamic stiffness, then deducing a transfer function, performing frequency compensation, and finally digitalizing the transfer function, so that the digital programmable piezoelectric acoustic metamaterial is realized. According to the active regulation and control method provided by the invention, parameter configuration can be conveniently carried out in real time according to the target frequency, and an obvious band gap and super-strong vibration attenuation exceeding 40dB are realized in a low-frequency range; moreover, the piezoelectric acoustic metamaterial is a multiple-input multiple-output (MIMO) system, the design complexity of the MIMO system is greatly reduced by the active regulation and control method provided by the invention, and a bridge is established for large-scale application of an active control algorithm in the piezoelectric acoustic metamaterial.

Description

technical field [0001] The invention belongs to the technical field of vibration control, and in particular relates to an active control method for piezoelectric acoustic metamaterials. Background technique [0002] Piezoacoustic metamaterials attach piezoelectric materials to the controlled structure by embedding or pasting, and connect the piezoelectric materials with shunt circuits to form a local resonant unit, which forms a periodic structure; Acoustic metamaterials have broad application prospects in the field of vibration and noise reduction due to their light weight, flexibility and high degree of design freedom. [0003] The local resonant unit of the periodic structure has elastic wave bandgap characteristics. Under the action of the bandgap, the propagation of elastic waves in the structure is hindered; the traditional shunt circuit is realized based on analog electronic devices, such as connecting the piezoelectric sheet to the LR shunt The circuit generates loc...

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Problems solved by technology

[0003] The local resonant unit of the periodic structure has elastic wave bandgap characteristics. Under the action of the bandgap, the propagation of elastic waves in the structure is hindered; the traditional shunt circuit is realized based on analog electronic devices, such as connecting the piezoelectric sheet to the LR shunt The circuit generates local resonance to realize a tunable vibration absorber; in order to enhance the local resonance band gap caused by the passive resonant shunt circuit, an enhanced shunt circuit (A-R circuit) was proposed, but the piezoelectric acoustic metamaterial formed by the analog shunt circuit is difficult Tune in real time, and have poor control at low frequencies

[0004] In order to solve the limitations of the analog shunt circuit, a digital impedance technology is proposed, which implements a synthetic impedance circuit by a microcontroller, which can establish the required impedance between the voltage on the piezoelectric element and the flowing current, while the existing The digital controller based on the AR circuit uses the zero-pole method to adjust the poles and zeros in the Young's modulus transfer function, which does not directly consider the negative dynamic stiffness, and the parameter configuration is inaccurate, and the formation of the piezoelectric acoustic metamaterial band gap depends on Whether negative dynamic stiffness can be generated, the dynamic stiffness of the system can be affected by changing the parameters of the shunt circuit, and the flexible adjustment of the local resonance bandgap can be realized

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