Abstract: The active triple-panel sound insulation structure with planar secondary source can be easily implemented and has better low frequency sound insulation performance. Error sensing strategy is one of the key problems encountered in the implementation of such a system. The error sensing strategy is implemented by laying the distributed displacement sensor, i.e., tailored polyvinlidene fluoride (PVDF) which can sense structural radiation modes, on outer radiated panel. The theoretical model is established by using vibro-acoustic coupling approach. And the appropriate control strategy and objective function are chosen. The design formulation for the shape of PVDF used for sensing the radiation modes is also derived. Subsequently, based on the rule of sound energy transmission through triple-panel system, the appropriate objective function for the triple-panel system is chosen. And the shape of PVDF sensor is designed in different frequency range for different radiation modes. Results obtained demonstrate that, due to the special sound energy transmission rule in the triple-panel system, only using the first three order radiation modes of the radiated panel as control objective can achieve prefect noise reduction. The design of the PVDF sensors with special shape needs to be accomplished only in their respective dominant frequency bands for the first three order radiation modes. As well as improving sensing precision, this can simplify the shape of PVDF.

Key words: Active sound insulation structure, Error sensing strategy, Planar source, Polyvinlidene fluoride sensors