Development of a pseudo-uniform structural quantity for use in active structural acoustic control of simply supported...

Active structural acoustic control has been an area of research and development for over two decades with an interest in searching for an "optimal" error quantity. Current error quantities typically require the use of either a large number of transducers distributed across the entire structure, or a distributed shaped sensor, such as polyvinylidene difluoride. The purpose of this paper is to investigate a control objective function for flat, simply-supported plates that is based on transverse and angular velocity components combined into a single composite structural velocity quantity, termed V(comp). Although multiple transducers are used, they are concentrated at a single location to eliminate the need for transducers spanning most or all of the structure. When used as the objective function in an active control situation, squared V(comp) attenuates the acoustic radiation over a large range of frequencies. The control of squared V(comp) is compared to other objective functions including squared velocity, volume velocity, and acoustic energy density. The analysis presented indicates that benefits of this objective function include control of radiation from numerous structural modes, control largely independent of sensor location, and need to measure V(comp) at a single location and not distributed measurements across the entire structure.