声学测温在混响和高噪声条件下的时延估计研究

Study on Time Delay Estimation in Acoustic Pyrometry Under Reverberation and High Noise Environments

针对电站锅炉冷态时的混响问题和热态时的高噪声问题,进行了时间延迟估计的仿真研究,并在实验室环境下分别模拟混响和高噪声工况,对声波飞渡时间的测量进行了实验研究.结果表明:对于混响环境,通过巴特沃斯滤波器对信号进行先期滤波处理,再利用基于PHAT互相关加权算法的时间延迟估计,可以有效去除混响影响;对于高噪声环境,基于巴特沃斯滤波和ML加权函数的互相关算法可以较好地消除炉膛背景噪声的影响.

To solve the problems of reverberation and high background noise respectively occurring in cold and hot surroundings of power plant boilers,both numerical simulation and experimental study were carried out on measurement of the acoustic transmitting time under corresponding conditions.Results show that under reverberation environments,the reverberation impact can be eliminated by pre-filtering relevant signals with Butterworth filter and by performing time delay estimation based on PHAT weighted crosscorrelation algorithm;whereas under high noise environments,the noise impact can be alleviated by crosscorrelation algorithm based on Butterworth filter and ML weighting function.