摘要
在使用一发一收低频反射超声方法对大厚度介质进行测厚过程中,采集到的反射超声信号存在有效波和直达波混叠的现象,常规的一维超声信号处理方法难以对其进行有效处理。针对该类信号混叠问题,提出了基于线性Radon变换的自适应相减处理方法,从二维角度出发,根据在时空域中,直达干扰呈规律一致性,而有效底面回波呈推移差异性的特点,通过将信号阵列转换至线性Radon域的方法,对经过投影汇聚的信号数据进行自适应相减算法处理,实现对直达干扰波的有效压制及分离,从而提高低频超声回波数据的分辨率。通过仿真数据处理验证了该方法的有效性,相应厚度解算相对误差不超过0.7%。仿真和实验结果表明,提出的方法能够很好地解决大厚度介质测厚情境中混叠超声信号的分离问题。
In the process of thickness measurement of large-thickness media using one-shot low-frequency reflection ultrasound method,the collected reflection ultrasound signal has the phenomenon of effective wave and direct wave mixing,which is difficult to be processed effectively by conventional one-dimensional ultrasound signal processing methods.In order to solve this kind of signal mixed problem,an adaptive phase subtraction processing method based on linear Radon transform was proposed.From the two-dimensional perspective,according to the characteristics that direct interference shows regular consistency and effective underside echo shows shift difference in time domain,the signal array was converted to linear Radon domain.In order to improve the resolution of low-frequency ultrasonic echo data,adaptive phase subtraction algorithm was applied to the signal data after projection convergence to effectively suppress and separate the direct interference waves.Finally,the effectiveness of the method is verified by simulated data processing,and the relative error of the corresponding thickness solution does not exceed 0.7%.According to the simulation and practical application results,the proposed method can well solve the separation problem of this kind of mixed ultrasonic signals.
作者
聂彬
赵英亮
聂鹏飞
王黎明
NIE Bin;ZHAO Yingliang;NIE Pengfei;WANG Liming(Shanxi Key Laboratory of Signal Capturing and Processing,North University of China,Taiyuan 030051,China;School of Information and Communication Engineering,North University of China,Taiyuan 030051,China)
出处
《中北大学学报（自然科学版）》
CAS
2023年第3期299-304,324,共7页
Journal of North University of China(Natural Science Edition)
基金
山西省基础研究计划项目(20210302124545)
山西省高等学校科技创新项目(2020L0301)
国家自然基金青年基金资助项目(62203405)。
关键词
超声测厚
自适应相减
线性Radon变换
混叠信号分离
低频超声
大厚度介质
ultrasonic thickness measurement
adaptive subtraction
liner Radon transform
mixed signal separation
low-frequency ultrasound
thick medium
