基于m伪随机序列的车内空传噪声传递特性辨识

Identification method of vehicle interior airborne noise transfer behavior based on m pseudo-stochastic sequence

根据车内空气传播噪声的源-路径-接受者模型,提出了传递路径函数的m序列相关辨识方法。仿真结果表明:该方法具有很好的噪声抗干扰性能。采用复杂可编程逻辑器件CPLD为核心器件,连接外围电路,设计了移位时钟频率可调、长度可选的m序列发生器。利用m序列发生器进行实车对比实验,结果表明:m序列方法的测试误差比白噪声法小1/3,辨识精度高;测试环境的本底噪声能提高40dB(A),抗干扰性好。

According to the source-path-receiver model of vehicle interior airborne noise,the m pseudo-stochastic sequence correlative identification method of transfer function was proposed.Simulation results demonstrated that the method has excellent noise immunity performance.A m sequence generator with adjustable shift clock frequency and optional register series was designed by the complex programmable logic device CPLD as core and external circuit.The field tests indicated that compared with broadband white noise sweep method,the identification method based on m sequence technique has advantages in accuracy and noise suppression.The test error ratio was less than 1/3,and the background noise of test environment could increase by 40 dB（A）.