Analysis And Implementation Of The Hybrid Active Noise Control System

With the continuous advancement of industrial technology and the increasing demands of people for the quality of living environment,noise control has become more and more important.In recent years,Active Noise Control(ANC)technology has been continuously developed,and its application scenarios have been increasing,becoming the fastest growing direction of noise control.Among the various control structures of ANC,a hybrid control structure with excellent comprehensive performance is a very important part.The hybrid control structure combines the advantages of the feedforward control structure and the feedback control structure,and has the advantages including good noise reduction effect,fast convergence speed and wide application range.In this paper,the structure of the Hybrid Active Noise Control(HANC)system and the method of the secondary path modeling are studied,and the traditional Hybrid Active Noise Control(CHANC)system is improved.In the CHANC system structure,there is a coupling problem between the feedforward portion and the feedback portion,and the reference signal and the error signal do not completely match.The CHANC system is improved and optimized at the structural level,and both problems are solved.The improved system decouples the feedback and feedforward portions of the existing structure so that the feedback portion is no longer correlated with the reference signal of the feedforward portion.And in the improved system,an additional adaptive filter is used,which is used to process the error signal,so that the error signal of the feedforward part and the feedback part is matched with the reference signal.Thereby the improved system is more adaptable in the actual environment and achieves better noise reduction effect.In the practical application scenario of the ANC system,the secondary path is mostly time-varying.In this paper,the Online Secondary Path Modeling(OSPM)is used to extend the structure of the HANC system,so that it can cope with the changes of the secondary path.Thereby the system is more adaptable in the actual environment and achieves better noise reduction effect.This paper not only completed the theoretical analysis and simulation experiment of HANC system,but also built the actual experimental environment.Based on DSP chip,the HANC system was implemented and the contrast noise reduction experiment was completed.The experimental result,the improved system can achieve better noise reduction effect,is consistent with the theoretical analysis and simulation experiments.The experimental results show that the improvement of the CHANC system is effective,and it has certain theoretical significance and practical value for the research of HANC system.