论文部分内容阅读
为解决同一薄层界面处的各次反射回波在时域上不可分离导致无法测厚的问题,提出利用小波变换模极大值对橡胶薄层超声回波信号奇异点进行检测的方法.信号奇异点构成模极大值曲线,极大值曲线产生周期性,相邻的极大值曲线对应入射时基体/橡胶界面和反射时橡胶/基体界面回波信号的到达时间,其差值为超声波在橡胶薄层中传播时间的2倍,取其平均值,计算出橡胶薄层的厚度.仿真结果表明,该方法的相对误差均在10%以内.经实例验证该方法是可行的.
In order to solve the problem of unmeasurable thicknesses of various reflected echoes at the same interface in time domain, a method of detecting the singular points of the echosensitive ultrasonic echo signal using wavelet transform modulus maxima is proposed. Singular points form the model maximum curve, the maximum curve produces periodicity, and the adjacent maximum curve corresponds to the arrival time of the rubber / matrix interface echo signal at the time of the substrate / rubber interface and the reflection, the difference is the ultrasonic The propagation time of the rubber layer is twice as long as it takes the average value to calculate the thickness of the rubber layer.The simulation results show that the relative error of the method is less than 10%, and the method is validated by an example.