基于自适应小波去噪法的精密超声波测距方法  

Precise ultrasonic ranging method based on self-adaptive wavelet de-noising

作　　者：诸葛晶昌[1] 吴军[2] 詹湘琳[1] 于之靖[1] 

机构地区：[1]中国民航大学电子信息与自动化学院,天津300300 [2]中国民航大学航空工程学院,天津300300

出　　处：《吉林大学学报（工学版）》2017年第4期1301-1307,共7页Journal of Jilin University:Engineering and Technology Edition

基　　金：国家自然科学基金项目(61405246;61102097);国家自然科学基金委员会与中国民用航空局联合项目(U1333105);中国民航大学科研启动基金项目(2010QD02S);中央高校基本科研业务费专项资金项目(3122014D023;2014QD11X)

摘　　要：超声脉冲飞行时间的精确提取决定了超声测距的精度,因此滤除接收信号中的噪声可有效提高其测距精度。针对传统的去噪方法无法随噪声的变化而自动调整去噪阀值和小波分层数的缺点,提出了一种自适应小波去噪法,通过实时提取接收信号中的噪声特征,自动选择最优的小波参数,有效地提高了接收信号信噪比,从而提高飞行时间提取精度。实验表明,在室内环境条件下测距误差小于0.28mm,可满足大部分工业制造领域的距离测量应用。The ranging accuracy of an ultrasonic ranging system depends on how to extract the time of flight of ultrasonic pulse exactly.Therefore,the de-noising method for ultrasonic receiving signals plays an important role in high precise ultrasonic ranging system.Traditional de-noising methods can not automatically adjust their de-noising threshold and wavelet layers due to the fixed model,which limits their use in different environment.In order to improve the efficiency of the de-noising method for ultrasonic receiving signals,a self-adaptive wavelet de-noising method is proposed.This method can automatically choose the optimal wavelet parameters through real-timely extracting the characteristics of the noise in received signals.Then,the time of flight measurement accuracy can significantly increased by improving the signal-to-noise ratio of the ultrasonic received signals.Verification experiments show that the measurement error is less than 0.28 mm in indoor environment,which meets most of distance measurement requirement for industrial manufacturing.

关 键 词：信息处理技术 超声波测距 自适应滤波 阈值调节 

分 类 号：TH915.05[机械工程]