Bai Mingsian R, Chen Hung-Yu, Yang Lihao, Huang Shin-Cheng
Department of Power Mechanical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan.
J Acoust Soc Am. 2019 Aug;146(2):1371. doi: 10.1121/1.5123465.
A time-domain underdetermined multichannel inverse filtering (TUMIF) technique is proposed for active feedforward control of noise in ducts. Traditionally, feedforward active control is formulated as an overdetermined inverse filtering problem which generally leads to non-zero residual noise. In this work, a multichannel control approach is presented from the perspectives of vector subspaces and model-matching framework. By introducing multiple secondary sources, the problem can be reformulated into an underdetermined system, which admits infinite number of exact solutions with zero residual noise. However, the finite impulse response filter obtained using the least-square method tends to be prohibitively long for real-time implementation. To tackle this problem, two sparse coding techniques, the least absolute shrinkage and selection operator algorithm and the orthogonal matching pursuit algorithm, are exploited to reduce the controller orders. Simulation and experiment results obtained using a digital signal processor demonstrated that a two-channel reduced-order TUMIF controller has achieved significantly higher noise reduction than the filtered-x least-mean-squares algorithm.
提出了一种用于管道噪声有源前馈控制的时域欠定多通道逆滤波（TUMIF）技术。传统上，前馈有源控制被表述为一个超定逆滤波问题，这通常会导致非零的残余噪声。在这项工作中，从向量子空间和模型匹配框架的角度提出了一种多通道控制方法。通过引入多个次级声源，该问题可以重新表述为一个欠定系统，该系统允许存在无限多个具有零残余噪声的精确解。然而，使用最小二乘法获得的有限脉冲响应滤波器对于实时实现来说往往长得令人望而却步。为了解决这个问题，利用两种稀疏编码技术，即最小绝对收缩和选择算子算法以及正交匹配追踪算法来降低控制器阶数。使用数字信号处理器获得的仿真和实验结果表明，两通道降阶TUMIF控制器实现的降噪效果明显高于滤波x最小均方算法。
