Error Sensing Design Method for Active Structural Acoustic Control Based on Acoustic Radiation Modes

WU Jinwu^{1, 2}  JIANG Zhe¹

(1. Institute of Vibration and Noise, Jiangsu University, Zhenjiang 212013;
2. Aviation & Mechanical Engineering College, Nanchang Hangkong University, Nanchang 330063)

Abstract: In order to acquire error information in an active structural acoustic control system, a new sensing strategy based on acoustic radiation modes to measure the adjoint coefficients of the first few order acoustic radiation modes is proposed. Controlling the adjoint coefficients of the first few orders of acoustic radiation modes can reduce efficiently the total sound power at low frequency. By measuring the vibrating velocity distributions at a few points of vibrating plate surface and solving the underdetermined equations of the radiation mode expansion, the adjoint coefficients approximate values of the first N order radiation modes can be obtained. The approximate values are taken as the corresponding error sensor signals of the control strategy based on acoustic radiation modes. With an example of the pinned-pinned plate, the error sensing strategy is discussed. The analysis and comparison of the numerical and experimental data show that the error sensing strategy is feasible and the adjoint coefficients values of the first N order acoustic radiation modes are more precise.

Key words: Active control   Acoustic radiation mode   Error sensor

CLC No: TB535

国家自然科学基金(50475120)和航空科技创新基金(07A56001)资助项目. Received 20070331, received in revised form 20071009

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