分散多通道有源噪声控制系统的稳定性和结构研究

The global low frequency noise attenuation for large volume noise sources is usually achieved by centralized multi-channel active noise control system. Potential disadvantages of centralized control design are that the control algorithm requires considerable processing power, the electrical connection between error sensors, the secondary sources and the controller requires a large amount of wiring and the convergence speed decreases as the number of channels increases. One way to minimize these problems is to use decentralized control to partition the system into a number of independent controllers, but acoustic coupling between individual control loops may affect the system stability. For decentralized multi-channel active noise control system, previous work studied the stability and performance of error sensors for single frequency or narrowband noise reduction in the free space and little studies were taken on the physical system optimization for global sound attenuation, which cannot meet its applications for broadband noise reduction and global sound attenuation in various sound fields. Therefore, the objectives of this project are to study the stability, robustness and system configuration of decentralized multi-channel active noise control system for broadband noise reduction in the free space, the free space with reflect surfaces and the practical sound field similar to workshop, respectively. The outcome of this project is to develop models to estimate the system stability and global attenuation performance for various sound fields and control methods. The significance of this project can be addressed in providing a simple and effective solution to reduce low frequency noise radiated from large volume noise sources.

大型复杂声源的低频降噪可采用全耦合集中控制有源噪声控制系统，此时遇到的主要困难是随着通道数增多，自适应算法运算量增大，收敛性能下降，且通道间接线繁杂，不利于控制实施。为解决这个问题，本申请提出采用分散多通道有源噪声控制技术，即将集中控制系统分为多个独立的控制系统，每个独立控制系统独立设计，但运行时通道间耦合会影响该系统性能。对该类系统，目前国内外相关研究仅限于自由场下单频或窄带降噪的稳定性分析，没有关于系统结构配置对全局降噪性能影响的研究，远不能满足实际应用中各种声环境下的降噪需求。为此，本申请拟在自由场，存在反射面的自由场和车间类似实际声场这三种声学环境中对这类系统宽带降噪的稳定性和系统空间结构进行系统研究。研究将建立多种声场中不同控制机制的宽带降噪稳定性和全局降噪性能预测模型，分析系统的稳定性和鲁棒性，优化系统空间结构，为大型复杂声源的低频降噪提供一种简单有效的解决方法。

本项目针对大型复杂设备的有源降噪困难，复杂度高，不利于实施等不足，提出采用分散多通道有源噪声控制系统实现大型复杂声源的有源噪声控制。项目从实际应用问题出发，研究了不同声场环境下的各种降噪方法的降噪性能，并给出了优化设计方法；探讨了几种有源实施方式的全局稳定性和降噪性能，提出了大型复杂声源有源实施的性能预测模型和简化方案，取得了预期研究成果，具有较大的科学意义和较好的应用前景。