作者:刘忆森1, 周松斌1, 韩威2, 黄可嘉2, 李昌3, 刘伟鑫3
作者单位:1. 广东省自动化研究所, 广东 广州 510070;
2. 广东省现代控制技术重点实验室, 广东 广州 510070;
3. 广东省现代控制与光机电技术公共实验室, 广东 广州 510070
关键词:空气耦合超声;非接触检测;相关算法;软包装热封缺陷
摘要:
为实现软包装热封缺陷的在线无损检测,将空气耦合超声检测技术应用于软包装热封缺陷检测。采用中心频率为1 MHz、焦点直径约1 mm的点聚焦空气耦合超声探头,并分别采用包络积分算法和相关算法对带有0.5~1.5 mm泄漏通道型缺陷的热封封口进行面扫描成像。实验结果表明该方法可实现软包装热封泄漏缺陷的非接触成像。将带通滤波后的超声信号包络与标准信号包络相关性系数作为成像特征量,可有效消除空气耦合超声的透射能量波动噪声。相对于包络积分算法,相关算法可显著提升图像信噪比以及小尺寸缺陷检出能力。
Air-coupled ultrasonic testing of flexible package seal defect based on correlation imaging method
LIU Yisen1, ZHOU Songbin1, HAN Wei2, HUANG Kejia2, LI Chang3, LIU Weixin3
1. Guangdong Institute of Automation, Guangzhou 510070, China;
2. Guangdong Key Laboratory of Modern Control Technology, Guangzhou 510070, China;
3. Guangdong Public Laboratory of Modern Control and Manufacturing Technology, Guangzhou 510070, China
Abstract: In order to realize online nondestructive testing of flexible package seal defects, air-coupled ultrasonic testing was applied to detect seal defects of flexible package. A spot focused air-coupled ultrasonic probe whose center frequency is 1 MHz and focus diameter is about 1mm was applied and envelop integration method and correlation method were applied to scan defects of 0.5 mm to 1.5 mm leakage paths in sealing areas. Results show that this method can realize the non-contact imaging of seal leak defects of flexible package. Taking the ultrasonic signal envelope and standard signal envelope correlation coefficients after band-pass filtering as imaging characteristic quantity can effectively eliminate transmission energy fluctuating noise of the air-coupled ultrasound. Compared with the envelop integration method, the correlation method can significantly improve the signal-to-noise ratio of images and the small defects detection ability.
Keywords: air-coupled ultrasonic;non-contact detection;correlation method;seal defect of flexible package
2016, 42(12): 111-115,120 收稿日期: 2016-02-09;收到修改稿日期: 2016-03-15
基金项目: 广东省科技计划资助项目(2013B091100013,2013B010134008,2015A010103008)
作者简介: 刘忆森(1985-),女,江苏徐州市人,助理研究员,博士,主要从事传感技术与无损检测研究。
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