Optimal placement of actuators for active structural acoustic control of a light-weight device casing

The idea of active casing is an approach to reduce device and machinery noise by controlling vibration of casing walls. However, for a successful active control, it is essential to mount actuators at appropriate locations on the vibrating structure. A method for determining the optimal placement of actuators for a single plate was presented by the authors in previous publications. In this paper the aim is to further develop the method and employ it for the device casing, where multiple walls of the structure are controlled. In the research a cuboid light-weight casing is used. An important complication with respect to the previous research of the authors is that the walls of the casing are connected directly, without a rigid frame, what significantly augments vibration coupling between the walls. Optimization criterion is based on maximization of a controllability measure of the system. A memetic algorithm is employed to find the optimal solution. Obtained results are validated experimentally.