STTR Phase I: Modular Feedforward Adaptive Noise Control

该小型企业技术转让（STTR）第一阶段项目旨在展示多用途有源噪声控制模块的概念，该模块可广泛应用于各种需要声学噪声控制的环境和市场。 数字信号处理器（DSP）已经成熟到基于最小均方（LMS）滤波器的有源降噪（ANR）是可行的。 然而，传统的LMS滤波器不能有效地响应非平稳信号，因此在电话之外，采用自适应前馈控制的基于DSP的商用噪声控制产品是不可用的。 该项目旨在开发一个ANR模块，该模块基于获得专利的李雅普诺夫调谐方法实现创新的自适应滤波器。 与传统的前馈LMS滤波器或反馈ANR相比，该方法显著提高了低频噪声抑制性能，增强了LMS滤波器跟踪和有效消除非平稳噪声的能力。 本阶段I STTR旨在评估使用Lyapunov调谐滤波器的ANR通用DSP模块的概念，该滤波器可应用于各种开放空间或源噪声消除问题。 开放空间ANR提供指定体积内的噪声衰减，而源消除减少了重型或轻型机械产生的源噪声。 第一阶段的任务重点是评估即插即用模块的潜力，由于创新的LMS滤波器，可以适应各种噪声源特性和使用该模块的声学环境的动态范围。 该研究和最终产品满足了社会对噪声治理技术的重大需求，以防止噪声和振动，减少职业性听力损失，并提高人类在嘈杂环境中的效率。 这种通用ANR模块的应用范围从在飞机或工程车辆机舱内乘客头部周围的空间中提供安静区到对易受噪声和振动影响的敏感仪器的声学和振动保护。 该模块为噪声控制咨询行业提供了一种快速部署有效改造ANR解决方案的方法，用于降低高噪声机舱（飞机，车辆和建筑设备）中机械设备和管道的噪声，并在制造/工业环境，机场和办公楼中创造安静的空间。

This Small Business Technology Transfer (STTR) Phase I project seeks to demonstrate the concept of a multipurpose active noise control module with broad application to a variety of environments and markets requiring acoustic noise control. Digital Signal Processors (DSP) have matured to the point where active noise reduction (ANR) based on least mean square (LMS) filters is viable. However, traditional LMS filters do not respond effectively to non-stationary signals, thus outside of telephony, commercial DSP-based noise control products employing adaptive feedforward control are unavailable. This project seeks to develop an ANR module that implements an innovative adaptive filter based on a patented Lyapunov tuning method. This method improves low frequency noise reduction performance significantly over traditional feedforward LMS filters or feedback ANR, and it enhances the LMS filter.s ability to track and effectively cancel non-stationary noise. This Phase I STTR seeks to evaluate the concept of a general purpose DSP module for ANR using Lyapunov-tuned filters that can be applied to a variety of open space or source noise cancellation problems. Open space ANR provides noise attenuation within a specified volume, while source cancellation reduces source noise created by heavy or light machinery. Phase I tasks focus on evaluating the potential for a plug-and-play module that, due to innovative LMS filters, can accommodate a variety of noise source characteristics and a range of dynamics of the acoustic environment in which the module is used. The research and eventual product meets a significant societal need for noise abatement technology to protect against noise and vibration, reduce occupational hearing loss, and increase human effectiveness in noisy environments. The applications for this general-purpose ANR module range from providing a quiet zone in the space around a passenger's head in the cabin of an aircraft or construction vehicle to acoustic and vibration protection of sensitive instrumentation that is subject to noise and vibration. The module serves the noise control consulting industry by providing a means of rapid deployment of effective retrofit ANR solutions for reducing noise due to mechanical equipment and ducting, in high noise cabins (aircraft, vehicle, and construction equipment), and by creating quiet spaces in manufacturing/industrial settings, airports, and office buildings.