基于分散式控制的双层加筋有源隔声结构研究

Active double-panel sound insulation structure has superior sound insulation performance in the low frequency range. Hence, it is widely applied as an effective low frequency control method in the acoustic design stage of the cabin structure of the aircraft, ship and ground vehicles. Now most of the research works existed in literatures is paying attentions only on the fundamental theoretical research of the simplified model, and the deeply theoretical investigations which takes into account the realizability of each part of the control system is rarely carried out. Hence, it offers limited guidance for the practical application of this technic. In order to filling this gap, this project provides a novel active sound insulation structure which uses the decentralized velocity feedback controllers to actively control sound transmission of the rib stiffened double-panel structure. Taking the coupling effects of the rib into account, the control system can be optimally designed as the active sound insulation performance is directly chosen as the cost function. The optimal control system not only has good control performance but also be more prone to practical application due to its simplified and compact structure. Therefore, it has better engineering implementation value. The proposed system is investigated in detail from the three following aspects, i.e., the establishment of the theoretical model and the optimization of the system, the analysis of physical mechanisms of active control, and the design of the stability criteria of the decentralized system. Some theoretical innovations are expected to be obtained in these aspects, and then a relatively complete theoretical guidance can be obtained for the design of active rib stiffened double-panel structure using decentralized velocity feedback controllers, which can theoretically guide the engineering implementation of this technic.

双层有源隔声结构具有优越的低频隔声性能，因而在飞机、船舶及地面交通工具的舱壁结构声学设计中受到广泛关注。现有研究大多仅针对简单模型并就其基本理论问题展开探讨，而对于将系统各部分的可实现性考虑在内的深化理论研究还较少，其理论成果对该技术工程应用的指导性并不强。项目提出一种基于分散式控制的双层加筋有源隔声结构，以有源隔声性能为目标并结合筋条的耦合作用对分散式系统进行优化配置，设计的新型结构性能良好且简洁紧凑实用性强，因而更具工程实现价值。项目从加筋有源隔声结构的建模及分散式系统的优化配置、有源隔声的物理机理分析及系统的稳定性准则设计三方面展开研究，重点在这些关键问题上获得理论突破，并形成较完整的基于分散式控制的双层加筋有源隔声结构的设计指导依据，为该技术的工程应用奠定理论基础。

双层有源隔声结构具有优越的低频隔声性能，因而在飞机、船舶及地面交通工具的舱壁结构声学设计中受到广泛关注。现有研究大多仅针对简单模型并就其基本理论问题展开探讨，而对于将系统各部分的可实现性考虑在内的深化理论研究还较少，其理论成果对该技术工程应用的指导性并不强。项目提出一种基于分散式控制的双层加筋有源隔声结构，以有源隔声性能为目标并结合筋条的耦合作用对分散式系统进行优化配置，设计的新型结构性能良好且简洁紧凑实用性强，因而更具工程实现价值。项目从加筋有源隔声结构的建模及分散式系统的优化配置、有源隔声的物理机理分析及系统的稳定性准则设计三方面展开研究，重点在这些关键问题上获得了理论突破。由于筋条的耦合作用，加筋板的模态为一组基板模态的叠加，且该组基板模态之间有能量的相互传递。分散式系统中分散单元应沿筋条方向布局，通过抑制筋条的振动来抑制基板模态之间的能量传递，从而抑制加筋板模态的振动，可达到用最少的分散单元数获得最大的有源隔声性能的目的；同时采用空间梯度加权和法构建误差传感策略，实现了用很少量误差传感器在任意位置布局下就能获得高效的传感性能的目的。由于横纵筋条的共耦合作用，构成辐射加筋板模态的基板模态组包含了基板所有的模态类型，该组内各基板模态之间均有能量的相互传递，空腔声场的调控对抑制辐射加筋板的振动起到关键重要作用，因此，有源隔声的主要机制突出体现在空腔声模态的抑制与重构现象并存，导致辐射加筋板振动的抑制。加筋提高了基板的共振频率，从而增大了加筋板第一阶共振频率与惯性激励固有频率之差，拓宽了采用惯性激励时分散式系统稳定的反馈增益阈值范围，同时增加惯性激励的阻尼来减弱惯性激励在固有频率处的共振幅度，也可拓宽稳定的反馈增益阈值范围。上述理论突破，形成了较完整的设计指导依据，为该技术的工程应用奠定了基础。