路面冲击输入下车内噪声主动控制

Active Control of Road Noise in Vehicles Running on Impulsive Road

针对基于LMS算法道路噪声主动控制在面对冲击性噪声时性能骤降的问题,建立了基于滤波-x最小平均绝对偏差(FxLMAD)算法的道路噪声主动控制系统,以控制路面冲击输入下的车内噪声。首先对路面冲击输入下车内噪声特性进行了分析,发现其噪声是非高斯的,且更符合α稳定分布。接着对基于FxLMAD算法的噪声主动控制进行仿真,结果表明该算法在达到良好降噪效果的前提下还拥有结构简单、计算量小的优点。最后,搭建了车内噪声主动控制系统并在某燃油车上完成了冲击路面的实车道路试验。结果显示,基于FxLMAD算法的车内道路噪声主动控制系统在50~500 Hz范围内的总声压级降噪量可达约2 dB(A),明显优于普通的LMS算法。

Aiming at the problem of performance drop of road noise active control based on LMS algorithm when facing impulsive noise, a road noise active control system based on filter-x least mean absolute deviation(FxLMAD) algorithm is built to control impulsive road noise inside a vehicle. Firstly, the characteristics of in-vehicle noise under the impulsive road condition are analyzed, discovering that the noise is non-Gaussian and more consistent with α stable distribution. Then, a simulation is conducted on noise active control system based on FxLMAD algorithm with a result indicating that the algorithm is simple in structure and requires less calculation efforts, while achieving good noise reduction effects. Finally, an active control system for in-vehicle noise is built and a real fuel vehicle road test is completed on impulsive road. The results show that with the active control system for in-vehicle road noise based on FxLMAD algorithm, the total sound pressure level in the range of 50~500 Hz reduces by about 2dB(A), apparently superior than that with the ordinary LMS algorithm.