Error sensing strategy for active acoustic structure based on distributed displacement sensors

Active acoustic structure proposed in recent years has been viewed as an encouraging approach to actively control sound radiation from vibrating structures. In this study, the nearfield error sensing approach, which is one of the key problems encountered in the implementation of such a structure, is investigated theoretically. The basic idea involves a limited number of PVDF film pairs be boned to the surface of the primary panel and secondary panels for measuring the total the radiated sound power. In this paper, first, a theoretical model associated with the active acoustic structure is established. Second, the formulae for the shape coefficient of the PVDF pairs are derived based on the acoustic radiation modes and a PVDF sensing model. Finally, a number of computer simulations are performed and the shape of the PVDF pairs and corresponding reduction in the radiated sound power are achieved. The results demonstrate the feasibility of the proposed nearfield error sensing strategy.