Sound shielding by a piezoelectric membrane and a negative capacitor with feedback control
Sound shielding by a piezoelectric membrane and a negative capacitor with feedback control
复制标题
DOI：
10.1109/tuffc.2008.869
复制
发表时间：
2008-08
期刊：
影响因子：
--
通讯作者：
T. Sluka;H. Kodama;E. Fukada;P. Mokry
中科院分区：
文献类型：
--
作者：
T. Sluka;H. Kodama;E. Fukada;P. Mokry
提出了一种基于压电材料有效弹性刚度控制的自适应声屏蔽系统的设计与实现方法。在该系统中，声屏蔽效果是通过从固定在刚性框架中的压电弯曲膜的声音反射来实现的，该压电弯曲膜连接到一个有源模拟电路，该有源模拟电路表现为负电容器。对于频率为1.6kHz且声压级为80dB的入射声，测量通过弯曲膜的声传输损耗。当系统中的负电容器被适当地调整时，通过负电容器的作用，传输的声音的声压级从初始的60 dB降低到15 dB。然后将系统暴露于自然变化的操作条件，并研究它们对隔音效率的影响。结果表明，在负电容调整后的30 min内，系统的透声损失下降了35 dB。因此，通过在负电容上附加数字控制电路，实现了系统的自调节。结果表明，通过控制电路的调节作用，上述劣化效应已被消除。自适应声屏蔽系统的声传输损失达到了60 dB的长期可持续值。
The design and realization of an adaptive sound-shielding system based on a method to control the effective elastic stiffness of piezoelectric materials are presented in this paper. In this system, the sound-shielding effect is achieved by a sound reflection from the piezoelectric curved membrane fixed in rigid frame and connected to an active analog circuit that behaves as a negative capacitor. The acoustic transmission loss through the curved membrane was measured for the incident sound of frequency 1.6 kHz and of acoustic pressure level 80 dB. When the negative capacitor in the system was properly adjusted, the acoustic pressure level of the transmitted sound was reduced from the initial 60 dB to 15 dB by the action of the negative capacitor. Then the system was exposed to naturally changing operational conditions, and their effect on sound-shielding efficiency was studied. It is shown that the acoustic transmission loss of the system dropped by 35 dB within 30 min from the moment of negative capacitor adjustment. Therefore, a self-adjustment of the system has been implemented by appending an additional digital control circuit to the negative capacitor. It is shown that the aforementioned deteriorating effect has been eliminated by the adjusting action of the control circuit. The long-time sustainable value of 60 dB in the acoustic transmission loss of the adaptive sound shielding system has been achieved.