Adaptive minimization of radiated sound power from lightweight structures with anti-noise

自适应最小化具有抗噪声功能的轻质结构的辐射声功率

• 批准号: 374502762
• 负责人: Professor Dr.-Ing. Delf Sachau
• 金额: --
• 依托单位: Professur für Mechatronik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/374502762?language=en
• 关键词: Adaptive; minimization; radiated; sound; power

One well-known application of anti-noise is the noise cancellation in an active headset. Here, sound immission (noise acting at the users ear) is reduced by anti-noise. In noise emission (thus noise emitting from a source) passive sound insulation such as insulation mats are used mostly. Weight and installation space limit the application at frequencies below 300 Hz. This gap can be closed by active noise treatments. The planned research project concerns with this task.Reduction of the radiation of structure-borne sound is both applied in free sound fields (e.g. noise radiated by electrical transformers) as well as in indoor space (e.g. noise within an aircraft cabin). Here, an adaptive control system generates actuation signals for anti-noise loudspeakers to minimize the sound pressure at microphones. Due to the spatial dependence of the sound field, a global noise reduction is possible only by the use of many microphones.The global noise reduction with a local arrangement of electromechanical and -acoustic transducers has long been discussed in the literature. Solutions for global active noise control (ANC) require the observability of global acoustic quantities such as the total potential sound energy in a weakly damped volume or the total radiated sound power into the free sound field. The feasibility of a local ANC system with unknown radiation impedance of the vibrating structure, while simultaneously controlling the total radiated sound power, has been poorly studied up to now.This approach offers the possibility of significantly reducing the quantity as well as the effort for position optimization of transducers in an ANC system. Preparatory work of the apprentices working group proves that adaptive minimization of total sound power is possible.This leads to the aim of the research project, that is the adaptive minimization of the total radiated sound power of a periodically-actuated plate structure in the frequency range between 80 Hz and 300 Hz with locally arranged loudspeakers and sensorsAnalytical and numerical methods as well as experimental investigations on a plate structure are the consequent step to the own preliminary work and already gained knowledge from the literature. The planned investigations form the basis for this research project and for the extension of the principle to a real lightweight structure. Thus fundamental experience about global noise reduction of sound emitting structures by a non-contact with electro acoustic actuators will be generated and prepared for applicability.

抗噪声的一个众所周知的应用是有源耳机中的噪声消除。在这里，通过抗噪声来减少声音输入（作用在用户耳朵处的噪声）。在噪声发射（因此从源发射的噪声）中，主要使用被动隔音，例如隔音垫。重量和安装空间限制了频率低于300 Hz的应用。这种差距可以通过主动噪声处理来弥补。计划中的研究项目涉及这一任务。减少结构声辐射既适用于自由声场（例如变压器辐射的噪声），也适用于室内空间（例如飞机机舱内的噪声）。这里，自适应控制系统生成用于抗噪声扬声器的致动信号，以最小化麦克风处的声压。由于声场的空间依赖性，只有使用多个麦克风才有可能实现全局降噪。在文献中，长期以来一直在讨论机电和声学换能器的局部布置的全局降噪。全局有源噪声控制（ANC）的解决方案需要全局声学量的可观测性，例如弱阻尼体积中的总潜在声能或进入自由声场的总辐射声功率。在结构辐射阻抗未知的情况下，采用局部ANC系统同时控制总辐射声功率的可行性研究较少，这种方法可以大大减少ANC系统中换能器的数量和位置优化的工作量。学徒工作组的准备工作证明，总声功率的自适应最小化是可能的。这导致了研究项目的目标，也就是周期性地使总辐射声功率自适应最小化，在80 Hz和300 Hz频率范围内，局部布置扬声器和传感器的驱动板结构的分析和数值方法以及板的实验研究结构是自己的初步工作的后续步骤，已经从文献中获得了知识。计划中的调查形成了本研究项目的基础，并将该原理扩展到真实的轻质结构。因此，通过与电声致动器的非接触，将产生关于声发射结构的全局降噪的基本经验，并为适用性做好准备。