有源头靠系统中次级声源和控制电路的参数优化研究

在有源头靠系统中,针对次级声源和控制电路两部分对模拟反馈有源控制系统(ANC)参数进行优化。为了达到更好的噪声抑制效果,次级声源的有效辐射频带应和待控制噪声的主要频谱相近,在使用电动扬声器作为次级声源时,其谐振频率应在要控制噪声频谱的下端。在优化控制电路参数时,根据经典控制理论提出合适的目标函数,通过差分演化算法进行优化。在有源头靠系统中,可通过适当调整两通道间距离,或将两通道间耦合纳入参数优化算法中,以保证系统稳定性和抑制"水床效应"的影响。模拟和实验表明两种方法各有利弊。在实际应用中需根据不同需要采用不同的优化方法。

Parameter optimization of secondary loudspeakers and compensators in active headrest

In application of active headrest,parameters of the secondary loudspeakers and compensators of analog feedback control systems should be chosen suitably.The effective radiation frequency of the secondary loudspeaker should be designed near the main frequency of the noise.If an electro-dynamic loudspeaker is used as the secondary loudspeaker,its resonant frequency should be designed near the lower end of the main frequency band of the noise.For the compensator optimization,the cost functions based on the classical control theory could be minimized by the differential evolution algorithm to obtain the best frequency response of the compensator.In the active headrest system,either tuning the distance between the two channels or counting the coupling affect into the cost functions should be performed to ensure the stability of the system and to restrict the waterbed effect.The results of simulation and experiment show that way to be chosen depends on the different situations of practical applications.