Increasing noise transmission loss across an aluminum panel using PZT actuators

The presence of noise and vibration in structures often adversely impacts the performance of such systems. Different methodologies have been developed by researchers for vibration and noise control. The feedback techniques that have been developed for active noise control in structures have the requirement of modal parameters of the structure. In this research, loop shaping technique has been implemented along with a PZT (Lead Zirconium Titanate) actuator for active control of noise across an aluminum panel. This technique combines the advantages associated with the loop shaping technique and PZT actuators. While the loop shaping technique eliminates the requirement of modal parameters for controller design, the PZT actuators have the advantages of being cheap and compact. Non-parametric system identification was conducted and the controller was designed in the frequency domain using the sensitivity charts. The test facility consists of a panel that is coupled to an enclosure containing a noise source. The noise used for exciting the panel is broadband in nature. Experiments were conducted in an anechoic chamber to eliminate the effects of echoes and external disturbances. Experimental results proved the capability of PZT actuators along with the loop shaping technique in increasing the noise transmission loss across an aluminum panel corresponding to the modal frequencies for broadband excitations of the panel.