A Multi-Sensor Feedback Control Framework for Active-Passive Sound Absorption

키워드

확장요약문

Passive sound absorbers have been widely used for acoustic treatment, but their performance deteriorates at low frequencies where achieving effective absorption requires a sufficiently large absorber thickness. In contrast, active control is particularly effective at low frequencies, where the acoustic field is more amenable to control due to the relatively long acoustic wavelengths. These complementary characteristics make hybrid active-passive absorbers an attractive solution for broadband sound absorption. And, in this study, a multi-sensor feedback control framework is proposed to incorporate acoustic pressure and particle velocity measured at different locations within the absorber. As illustrated in Fig. 1, seven sensing signals are integrated through a sensing matrix and used as inputs to a PID feedback controller.

The proposed framework was evaluated using the finite element model by comparing the passive system alone with active-passive single-, pair-, and all seven- sensor configurations. As shown in Fig. 2, the mean absorption coefficient increased as additional sensors were incorporated. While the passive system yielded a mean absorption coefficient of 0.83, the single- and pair-sensor configurations achieved 0.91 and 0.97, respectively. The all sensor configuration achieved 1.00, indicating near-perfect absorption over the target frequency range of 100 – 2000 Hz. These results demonstrate the potential of multi-sensor feedback control to enhance broadband absorption in active-passive systems.