基于声辐射模态有源控制的误差传感器设计方法

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

为了获取有源结构声学控制系统中的误差信息,提出一种基于声辐射模态的误差传感策略来测量振动结构前几阶声辐射模态伴随系数。在低频时,控制前几阶声辐射模态伴随系数可以有效控制总声功率。通过在振动平板上测量少数点的振动速度分布,求解声辐射模态展开构成的欠定方程组,得到前Ⅳ阶声辐射模态伴随系数近似值,以此近似值作为基于声辐射模态有源控制策略对应的误差传感器信号。以四边位移为零的振动板为例,对上述误差传感策略进行分析讨论。仿真和试验结果都表明误差传感策略是可行的,所获得的前N阶声辐射模态伴随系数具有较高的精度。

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.