Design strategy and algorithm for adaptive control of active sound absorption

For using method of active control to construct low frequency absorption surface, the two kinds of adaptive control strategies, i.e. minimum sound reflection power and minimum normal velocity in limited points of the elastic plate, were proposed. If the secondary source, number of monitoring sensors and their installed location were properly selected, the satisfactory absorption effect will be achieved by regarding the minimum normal velocity as control objective. The multi-channel filtering algorithm based on least mean square criterion was presented. The simulation result for control of the inclined incident sound has shown that the control method is feasible.