Research On Hybrid Vibro-Acoustic Active Control Method For Vehicle Interior Sound Quality

In order to reduce the low-frequency components of vehicle interior noise,active noise control(ANC)and active vibration control(AVC)methods have attracted much attention from researchers,but blindly reducing the noise cannot satisfy the subjective feelings of the passengers.Active sound quality control(ASQC)method provides a new idea for solving this problem.Vehicle interior noise is composed of air noise and radiated noise caused by structural vibration.However,the existing ANC and AVC methods only focus on noise or vibration control,and the impact of vibration control on noise control is rarely taken into account.Therefore,the ASQC method and the AVC method are combined to carry out an indepth study of the hybrid vibro-acoustic active control method for vehicle sound quality in this thesis.The main research contents include:(1)Based on the vibration-acoustic transfer function,a hybrid vibro-acoustic filter-u and filter-x least mean square(HVA-FUXLMS)algorithm for vehicle interior noise is proposed.This algorithm calculates the amount of radiation noise change caused by vibration control in real time.Then,the noise control is performed for the processed ear-side noise to achieve the purpose of taking both vibration and noise control into consideration.Taking noise and vibration at idle condition as an example,the vibration and noise are effectively controlled by the proposed HVA-FUXLMS algorithm.Compared with the filterx least mean square(FXLMS)algorithm,the mean absolute error of residual noise is reduced by 4%,and the convergence speed is improved by 0.104 seconds.(2)Considering the error in the calculation of radiated noise from the vibration-acoustic transfer function,a hybrid vibro-acoustic delay-time least mean square(HVA-De LMS)algorithm is proposed is proposed based on the delay time interval.Vibration and noise are controlled by the hierarchical strategy.First-level vibration control is implemented first,and the second-level noise control is performed after the vibration reaches a convergence state after a delay interval.Unlike the HVA-FUXLMS algorithm,the vibration has reached a convergent state and the radiated noise tends to stabilize while the secondary noise control of the HVA-De LMS algorithm starts,which can avoid the influence of the vibration control on the noise control.The vehicle interior noise and vibration at idle condition are used to simulated.The results show that the HVA-De LMS algorithm can realize the hierarchical control of noise and vibration,and have a good effect on the main frequency band of 0?200Hz of the noise.(3)To control the sound quality,a sound retention factor is introduced on the basis of the HVA-FUXLMS algorithm,a hybrid vibro-acoustic adaptive noise equalizer(HVA-ANE)algorithm is proposed based on the adaptive noise equalizer(ANE)algorithm.The empirical mode decomposition(EMD)method and the frequency-domain block method are introduced to further propose a hybrid vibro-acoustic empirical-mode-decomposition frequencydomain block adaptive noise equalizer(HVA-EBANE)algorithm.Based on the filter-error least mean square algorithm(FELMS)algorithm,a hybrid vibro-acoustic empirical-modedecomposition frequency-domain block filter-error least mean square(HVA-EBFELMS)algorithm is proposed.The simulation results of the three algorithms show that the HVAEBFELMS algorithm reduces the loudness of ear-side noise by more than 40% while taking into account noise and vibration control.The loudness control effect of HVA-EBFELMS algorithm is better than the HVA-ANE algorithm and the HVA-EBANE algorithm.Therefore,the HVA-EBFELMS algorithm has a good loudness improvement effect.(4)Taking high-speed working conditions as an example,a simulation of ASQC based on HVA-ANE and HVA-EBFELMS was performed for three psychoacoustic indicators of loudness,roughness,and sharpness.The results show that the HVA-EBFELMS algorithm reduces noise loudness by 34.93%,while the HVA-ANE algorithm reduces 31.78%.However,in the control of sharpness and roughness,the two algorithms are only effective in a few critical frequency bands,and the general effect is not ideal.The hybrid vibro-acoustic active sound quality control algorithm for vehicle interior noise studied in this thesis can effectively improve the vehicle interior sound quality.It provides good theoretical and application value for active control of vehicle interior noise and related engineering noise.