Adaptive feedback controller with open-loop transfer function reference suited for applications such as active noise control

An adaptive feedback controller comprising:

• a feedback control loop comprising an adaptive filter, said feedback control loop generating a filtered error signal;
• a residual loop identifier coupled to said feedback control loop to receive therefrom said filtered error signal, said residual loop identifier configured to generate a parameter of an estimated residual loop transfer function in response to said filtered error signal;
• and
• an open loop adaptor coupled to said residual loop identifier and to said adaptive filter, said open loop adaptor configured to receive from said residual loop identifier said parameter of said estimated residual loop transfer function and to form a new adaptive filter coefficient, said open loop adaptor configured to copy said new adaptive filter coefficient to said adaptive filter, so as to adjust a behavior of said feedback control loop.