Academy for Engineering & Technology, Fudan University, Shanghai 200433, China.
Academy for Engineering & Technology, Fudan University, Shanghai 200433, China; Center for Biomedical Engineering, School of Information Science and Technology, Fudan University, Shanghai 200438, China.
Ultrasonics. 2022 Sep;125:106802. doi: 10.1016/j.ultras.2022.106802. Epub 2022 Jul 8.
Measurement deviation of time of flight (ToF) is inevitable in nondestructive testing based on the sparse array and ultrasonic Lamb waves. It affects the influence zone of temporal-spatial mapping trajectories (TSMTs) of signal parameters in the imaging zone, and further limits the quantitative evaluation of defect localization. In the paper, the ellipse of uncertainty (EOU) of TSMTs was derived from multiple parameters, including the group velocity, ToFs and their measurement deviations, distances between actuators and receivers. Then, an EOU-based algorithm was developed for quantitative evaluation of defect localization. The defects were localized by searching the individual scatterers at the intersection of multiple TSMTs. Based on the eccentricity of the uncertainty ellipse, a fuzzy scaling factor was introduced. It was combined with a fuzzy control parameter to tune the influence zone of TSMTs. Based on the acoustic reciprocity theorem and the fuzzy control parameter, the ToFs of scattering waves were fused to establish the one-to-one relation between individual scatterers and inspection pairs. Experimental results showed that the EOU-based algorithm can reduce the interferences of EOU in the detection; and the quantitative evaluation of defect localization was realized by analyzing the distribution of individuals and their ToF difference to inspection pairs.
基于稀疏阵和超声波兰姆波的无损检测中，飞行时间（ToF）的测量偏差是不可避免的。它会影响信号参数的时-空域映射轨迹（TSMTs）在成像区域中的影响区域，从而限制了对缺陷定位的定量评估。本文从多个参数中推导出了 TSMTs 的不确定椭圆（EOU），这些参数包括群速度、ToF 及其测量偏差、换能器和接收器之间的距离。然后，开发了一种基于 EOU 的算法来对缺陷定位进行定量评估。通过在多个 TSMTs 的交点处搜索单个散射体来定位缺陷。基于不确定性椭圆的偏心率，引入了一个模糊比例因子。它与模糊控制参数相结合，调整了 TSMTs 的影响区域。基于声互易定理和模糊控制参数，融合散射波的 ToF 以建立单个散射体与检测对之间的一一对应关系。实验结果表明，基于 EOU 的算法可以减少检测中 EOU 的干扰；并通过分析个体的分布及其与检测对的 ToF 差异来实现缺陷定位的定量评估。
