Adaptive Resonant Mode Active Noise Control

摘要: Low frequency sound waves propagating in a duct is ideally suited for active noise control(ANC) applications. Unlike passive treatments, ANC utilizes an acoustic actuator (loudspeaker)to cancel unwanted fields. There are two main control topologies whenconsidering the suppression of sound, feedforward and feedback. The former requiresthat disturbance be known before signal generated, ideal periodicor random signals. Feedback arrangements, on other hand, modify dynamics anenclosured field to augment damping, requires no priori knowledge disturbance.A modified version feedback that used structures called positive positionfeedback (PPF), can applied systems. In previous study, tuned resonantfilter modelled after Helmholtz resonator was PPF configuration suppress noiselevels by Bisnette Vipperman (2004). However, presence speaker necessitatesfurther phase compensation, which accomplished with all-pass filter. workpresented here further develops this method using higher-order compensator. Inthis band-pass filters improve multi-modal limiting phaseinteraction adjacent modes. Further refinements made realizing systemelectronically, gives ability adapt controller parameters. Here, algorithmis presented adapts resonant gain. Experimental results show moderatereductions energy spill-over next uncontrolled mode.