Active control method for vibration of piezoelectric structure for adaptive narrow-band filtering

Abstract

The invention relates to an active control method for vibration of a piezoelectric structure for adaptive narrow-band filtering. A swept-frequency signal of a narrow band is used as an identification signal; and compared with a conventional white noise signal, the swept-frequency signal has the advantages that the energy of the swept-frequency signal is more intensive, and a piezoelectric element can be effectively driven to realize full excitation of the structure and increase the signal-to-noise ratio of a response signal, to enhance the control effect of the whole control system. A main channel control algorithm adopts a step length change algorithm to update a step length factor, and a secondary channel also adopts a step length change updating algorithm during on-line identification. Compared with an adaptive fixed-step-length updating algorithm, the active control method has the advantages that the convergence speed of the algorithm is obviously improved, and a stabilization error value is further reduced. Due to the step length change algorithm, the speed and the precision of the on-line identification of the secondary channel are improved.

Description

technical field [0001] The invention belongs to the field of active vibration control (AVC), and relates to an active control method for piezoelectric structure vibration with narrow-band self-adaptive filtering. Background technique [0002] In recent years, the active control method based on piezoelectric structure vibration has made outstanding progress. This control method has good low-frequency vibration suppression effect, strong adaptability to the environment, and small additional mass. It is currently one of the most ideal vibration suppression methods. Currently, piezoelectric structures have been used to overcome vibration problems induced by harmonic disturbances. Among them, adaptive filter feedforward control technology has become the mainstream method for active control of piezoelectric structure vibration due to its advantages of less calculation and easy implementation. The core idea of ​​this type of method is to design such an adaptive filter, that is, th...

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Problems solved by technology

If the step size is too large, it is easy to cause the algorithm to be unstable

Although the existing patent "ZL201310108307.9" invented the variable step size LMS (minimum mean square error) adaptive controller update algorithm, but for the variable step size algorithm of the FxLMS controller in the case of narrowband interference, and the online identification of the secondary channel The variable step size algorithm does not mention

[0007] The existing problems in the existing technology are: (1) The existing online identification method uses white noise as the input signal for the online identification of the secondary channel, which cannot effectively drive the piezoelectric element to achieve sufficient excitation of the structure, which seriously affects the identification effect of the secondary channel

(2) Most of the traditional FxLMS algorithms use a fixed step size to update the weights, which cannot take into account the convergence speed and stability error of the algorithm

(3) As a feedforward control method, the adaptive filtering method generally needs to measure the reference signal first to design the controller, but in many engineering occasions it is impossible to directly obtain the reference signal representing the external disturbance

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