激光焊接过程多传感器在线检测系统的设计

为了提高激光焊接质量实时检测的可靠性,采用虚拟仪器平台LabVIEW搭建了多通道信号采集和分析系统,同时检测激光焊接过程中与焊接质量密切相关的可听声(20Hz~20kHz)、等离子体蓝紫光(400nm~500nm)、红外辐射(1200nm~1600nm)等3路信号。采用数字信号处理手段分析了3路检测信号的相关性,发现两路光信号变化完全同步,而声信号在时间上滞后于两路光信号,滞后时间等于声音传播所需要的时间,验证了所采集3路信号的有效性;并通过实例证明了采用多传感器检测在可靠性方面的优势。实验结果表明,采用多传感器检测与进一步的信息融合是实现激光焊接过程实时监测的发展方向。

Design of multi-sensor on-line monitoring system for laser welding

To improve the reliability of the real-time monitoring for laser welding,a multi-sensor signal sampling and processing system was built based on LabVIEW,a virtual instrument development tool.Three signals of audible sound(20Hz~20kHz),plasma optical emission(400nm~500nm),and infrared emission(1200nm~1600nm) during the laser welding process,were picked up and analyzed.Correlation analysis of the three signals shows that the two optic signals are synchronous and the audible sound signal is hysteresis to the optic signal.The hysteresis time is just equal to the sound transferring from welding point to senor,which proved the validity of the three detecting signals.Two examples show that the reliability of multi-sensor monitoring is higher than single sensor monitoring.So,the multi-sensor detecting and signal fusion is the developing direction for the laser welding monitoring in the future.