Performance Assessment of an Active Noise Reduction System

In the past decade the field of smart structures and intelligent material systems received a lot of scientific attention. Numerous publications deal with the modeling, design, optimization and performance evaluation of such systems, in which beams, plates or truss structures are often considered as test cases. In the application of this promising new technology to real systems, the designer is often confronted with problem specific issues, e.g. proper formulation of the desired output function, integration of the actuators, sensors made of multifunctional materials and the control scheme to the system model, etc. As an example, the performance assessment of an active fac¸ade system is presented in this paper. The fac¸ade system consists of distributed piezoelectric sensors and actuators bonded to the surface of the doubleglazed windows. An adaptive feedforward control scheme was implemented to reduce the noise transmission via the active fac¸ade. The performance of the active system with four sensor/actuator pairs was first demonstrated in a numerical simulation. A Digital Signal Processing System was used to validate the performance of the system with the help of a demonstrator fac¸ade, showing the reduction of the ambient noise experimentally for different types of harmonic and transient excitation.