Lin Cikai, Liu Daipei, Eggler Daniel, Kessissoglou Nicole
School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, New South Wales, Australia.
J Acoust Soc Am. 2021 Mar;149(3):1803. doi: 10.1121/10.0003556.
Acoustic cloaking has received significant interest due to the appealing ability to render an object acoustically invisible. In a similar concept to acoustic cloaking, acoustic illusions provide the capability to misrepresent the acoustic field of an object. Combining acoustic cloaking and illusions with numerical discretization methods allow objects of greater complexity to be considered. This work presents active acoustic cloaking and illusions of three-dimensional rigid objects. The boundary element method is utilized to efficiently predict the exterior acoustic domain. A multi-input/multi-output control system comprising monopole control sources, error sensors, and a controller based on a feedforward linear-quadratic regulator algorithm is employed. Active acoustic cloaking of a simple object corresponding to a sphere is demonstrated for both non-decaying and decaying incident fields. For the same control configuration but minimizing a cost function based on different error signals, acoustic illusions are generated to mimic the presence of a sphere within a free field. Illusional fields are also generated for a cube and a bird to misrepresent their size or orientation.
由于具有使物体在声学上不可见的诱人能力，声学隐身技术引起了广泛关注。与声学隐身类似的概念中，声学错觉提供了歪曲物体声场的能力。将声学隐身和错觉与数值离散化方法相结合，可以考虑更复杂的物体。这项工作展示了三维刚性物体的有源声学隐身和错觉。利用边界元法有效地预测外部声学域。采用了一个多输入/多输出控制系统，该系统包括单极控制源、误差传感器和基于前馈线性二次调节器算法的控制器。针对非衰减和衰减入射场，都展示了对应于球体的简单物体的有源声学隐身。对于相同的控制配置，但基于不同的误差信号最小化成本函数，生成声学错觉以模拟自由场中球体的存在。还为立方体和鸟生成了错觉场，以歪曲它们的大小或方向。
