Modelling, system identification, and control of acoustic-structure dynamics in 3-D enclosures

This paper addresses modelling, system identification, and control of acoustic-structure interaction dynamics for 3-D enclosures. The specific configuration of interest is the one in which an acoustic disturbance is created by one of the vibrating boundaries of the enclosure such as in the case of aircraft cabin noise. The modelling techniques developed in this paper can be used to obtain finite-dimensional approximate models (time-domain as well as frequency-domain) suitable for control design. The mathematical modelling approach presented in this paper can be extended to model a broad class of acoustic-structure systems. The modelling methodology is demonstrated on a 3-D acoustic enclosure built in laboratory for experimental verification. The analytical model is compared with the experimental data. The transfer function and state-space models are also obtained from experimental data using system identification techniques. Differences in analytical and experimentally identified models are discussed and control design strategies along with experimental results are presented for broadband reduction of noise.