An adaptive controller for the active absorption of sound
An adaptive controller for the active absorption of sound
复制标题
主动吸声的自适应控制器
DOI：
10.1121/1.403779
复制
发表时间：
1992
影响因子：
2.4
通讯作者：
P. Nelson
中科院分区：
文献类型：
--
作者：
F. Orduña;P. Nelson
提出了一种自适应系统，其允许次级声源在封闭管道的端部处成为声音的主动吸收器。该系统也可以推广，以实现其他终端阻抗。该系统由一个扬声器、两个麦克风和包括数字信号微处理器的信号处理硬件组成。来自麦克风的信号被处理以获得表示终端的实际声阻抗和期望声阻抗之间的差的误差信号。例如，吸收终端要求麦克风对充当单向探头，仅拾取从有源终端反射的声音。该信号被用作数字控制器需要最小化的误差信号。一个简单的分析表明，这可以通过使用“filtered-X”LMS算法自适应地完成。一个简单的实验装置是用来获得一个吸收终端，这是工作与周期性的，随机的，和瞬态…
An adaptive system is presented that allows a secondary acoustic source to become an active absorber of sound at the end of a closed duct. The system can also be generalized in order to achieve other termination impedances. The system consists of a loudspeaker, two microphones, and signal processing hardware including a digital signal microprocessor. The signals from the microphones are processed to obtain an error signal that represents the difference between the actual and the desired acoustic impedance of the termination. An absorbing termination requires, for example, that the microphone pair acts as a unidirectional probe picking up the sound reflected from the active termination only. This signal is used as the error signal that the digital controller is required to minimize. A simple analysis shows that this can be done adaptively using the ‘‘filtered‐X’’ LMS algorithm. A simple experimental setup is used to obtain an absorbing termination which is shown to work with periodic, random, and transient...