724 Noise reduction in a helmet by Active Noise Control

Abstract

W6 propose ANC ( ac もtve noise control )with IMC ( interna乳 model contro1 )in FB controL ． This IMC is known as a robust control design method especially fbr non − 1inear systems ． Noise is removed by activdy con もrolled secondary sound waves ． The perfbrmance ofFB − ANC can be predicted by investiga もillg もhe sensitivity fUnction． W ¢ examine realization of this control system by using simulation ． We can reduce the noise level remarkably over lower 貸 equency