Anti noise system and method, in particular for suppressing sound radiated from a structure, using a formulation of the most efficiently radiating vibration patterns of a vibrating body, the radiation modes, in the time domain. The radiation modes can be used to arrive at efficient weighting schemes for an array of sensors in order to reduce controller dimensionality. The particular radiation modes are determined on the basis of broadband signals. A method is given to obtain these modes from measurable signals on nearfield sensors and microphones in the farfield. The broadband radiation modes are used for the design of an actuator array in a feedback control system to reduce sound power radiated from an object. Three different methods for the design of the actuator are compared, taking into account the reduction of radiated sound power in the controlled frequency range, but also a possible increase of radiated sound power in an uncontrolled frequency range.
|Publication status||Submitted - 6 May 2002|