ASAC系统中少测点条件下的近场声压误差传感策略

Near Field Pressure Error Sensing Strategy under Less Measurement Point Condition for ASAC Systems

根据有源控制策略设计简洁、有效的误差传感非常关键。针对基于声压声辐射模态的有源控制策略,具体设计与之对应的少测点条件下近场声压误差传感策略。首先,通过分析声压声辐射模态的空间滤波特性,证明基于声压声辐射模态的有源控制策略可行;然后,利用近场测量面上有限个测点的声压分布,通过求解模态展开所构成的欠定方程组的最小模最小二乘解,获取前K阶声压声辐射模态伴随系数的近似值,从而形成与基于声压声辐射模态的有源控制策略相对应的近场声压误差传感策略;最后,以置于无限大障板上的钢质简支薄板为例,进行数值仿真分析。结果表明设计的误差传感策略可行,所获得的前K阶声压声辐射模态伴随系数具有较高的精度。

It is very important to design a simple and effective error sensing system on the basis of active control strategy. In this paper, aiming at the active control strategy based on pressure acoustic radiation modes, an equivalent nearfield pressure error sensing strategy under less measurement point condition is designed in detail. First of all, by analyzing the spatial wave-filtering characteristics of the pressure acoustic radiation modes, the feasibility of the active control strategy based on the pressure acoustic radiation modes is proved. Then, by measuring the pressure distributions at a few measurement points in the near- field measurement surface and solving the underdetermined equations made of modal superposition, the approximate adjoint coefficients of the first K order radiation modes can be obtained. Thus, a near- field pressure error sensing method corresponding to the active control strategy based on the pressure acoustic radiation modes is developed. Finally, a simply supported steel plate in an infinitely large baffle is simulated as an example. The results show that the error sensing strategy proposed is feasible and the approximate adjoint coefficients of the first K order radiation modes are more precise.