基于小波变换的虚拟式声级计的设计及实现

摘要

Traditional sound level meters are deficient in measurement accuracy and parameter adjustment. In this paper,a wavelet transform based on the method for sound level measurement has been proposed. Instead of traditional FFT,wavelet transform is applied to analyze the frequency components of noise sound,so that the measurement result can be achieved with summation of the components multiplied by the ISO proposed weights. This algorithm is implemented on LabVIEW platform which brings about easy implementation and friendly interface between the measurement system and the user. Moreover,by programming with DataSocket,multiple measurement spots can be connected,so that the data from multiple spots can be integrated for further analysts and utilization. Verification has been done and it shows the system is able to make accurate measurement of the noise sound level.%为了克服传统声级计测量精度不高、电路参数调整困难的缺陷,使用小波变换代替传统的FFT对非平稳的噪声信号进行时频分析以获得更准确的噪声各频率成分的幅值,从而在对频率成分进行加权后获得更为准确的声级测量值.利用虚拟仪器技术,在LabVIEW开发环境中采用G语言对算法做了软件实现,它结合PC强大的软硬件资源实现了整个测量系统.为有效实现对多点测量数据的分析和利用,应用LabVIEW的DataSockct编程接口实现了测量数据的网络传输.经测试,该虚拟式声级计达到了较高的测量精度并且具有功能丰富、使用方便的优点.