Control of an acoustic mode by a digitally created Nonlinear Electroacoustic Absorber at low excitation levels: Experimental results
Résumé
In this study, an acoustic mode of a tube is controlled by a digitally created Nonlinear Electroacoustic Absorber (NEA) at low excitation levels, where the nonlinearity cannot be normally activated in passive vibro-acoustical absorbers. A comparison is carried out between a linear Electroacoustic Absorber, similar to a Tuned Mass Damper (TMD) in mechanics, and a digital NEA. The innovative method for creating a NEA lies on Real Time Integration of the dynamics of the device. It permits to choose any behavior of the system by digitally programming the corresponding targeted dynamics. Here, a loudpspeaker Impedance Control law with a cubic stiffness is considered, as this system is well known in mechanics and provides nonlinear phenomena that are highlighted at low and moderate excitation levels in our study.