Active structural acoustic control of plates with different boundary conditions using a weighted sum of spatial gradients

The control metric used in active structural acoustic control (ASAC) is a very important factor, as it directly impacts the radiated sound power control results. Previous work has identified a control metric referred to as the weighted sum of spatial gradients (WSSG), which has demonstrated effectiveness in attenuating the radiated power from a plate. It has been found that the weights used by WSSG have a direct impact on the control performance. Hence further work that investigates the weights and the control performance is presented in this paper. Two new methods to obtain the weights are proposed - one for single frequency excitation and the other for broadband frequency excitation. One of these methods, referred to as the parameter-based weights method, can be determined using only the ratio of the flexural rigidity to the mass per unit area, and hence is easy to obtain. These methods are compared with the original method, which uses a set of averaged weights. Both numerical and experimental work has been performed for simply-supported, clamped and ribbed plates. The results indicate that using these new WSSG methods leads to better performance and has the potential for practical implementation.