SPATIAL CHARACTERISTICS OF ACOUSTIC BOUNDARY CONTROL FOR INTERIOR NOISE SUPPRESSION

摘要

Suppressing interior sound radiation in aircraft andautomobiles is a important problem. There are two mainstreammethods for this problem: active noise cancellation (ANC) andactive structural acoustic controls (ASAC). An ANC systemoften requires a high dimensionality to achieve the level ofglobal noise reduction in a three dimensional volume thatASAC systems with a relatively low dimensionality are capableof, while actuators for structural control systems are powerintensive. There are also concerns that structural controls maycause damages to the structure. This paper develops an acousticboundary actuation method that may retain the advantages ofboth methods. Steady-state optimal noise control in arectangular enclosure is studied by using the proposed method.Simulation results are presented to demonstrate the ability ofacoustic boundary controls to cancel noise fields due to varioussources. A study of the spatial characteristics of the acousticboundary control as a function of frequency and relative phase ofdisturbances is also presented. Numerical simulations uncoveran interesting phenomenon on the variation of the optimalcontrol vector which may have significant implications to theactuator grouping studies.