摘要
脉冲涡流检测中缺陷信号会受到提离效应的严重干扰。采用带控制量的自回归(ARX)模型的系统辨识方法分析提离效应。首先,利用传感器处于空气中测得的信号作为输入信号,分别以不同提离高度测得的信号作为输出信号,然后利用最小二乘法对模型的参数估计后得到不同参数的ARX模型。结果表明,系统模型的高频特性可在检测时用来指示试件内部较深缺陷的不同提离高度。
Defect signal in pulsed eddy current testing（PEC）will be severely disturbed by lift-off effect.This paper adopts system identification method of ARX model to analyze lift-off effect.By using the signal tested by sensors in the air as input signal and the signal tested at different lift-off heights as output signal,the least-square method was used to estimate the parameter of the model in order to obtain ARX model with different parameters.The result of the model shows the frequency characteristics of systematic models can be used to indicate different lift-off height of defects in deeper position inside the specimens during the test.
出处
《无损检测》
2015年第12期20-23,27,共5页
Nondestructive Testing
基金
国家自然科学基金资助项目(51067007
51267016)
关键词
脉冲涡流检测
ARX模型
最小二乘法
提离效应
Pulsed Eddy Current testing
ARX model
The least-squares method
Lift-off effect
