激光焊接典型熔透状态信号特征分析及其识别

应用自行研制的多通道信号传感系统,实时采集可听声、蓝紫光以及红外辐射等三路信号.设计了楔形板焊接和阶梯板焊接两组试验,并采用RMS平滑、STFT分析和特征频段信号提取等手段分析信号.结果表明,可听声和蓝紫光信号RMS值和2 000～3 500 Hz频段信号幅值,在过熔透时极低,在完全熔透时很高,在未熔透时介于两者之间,三种熔透状态分界线明显,不稳定熔透时,三路信号波动较大,信号值比完全熔透时略低.可最终实现四种熔透状态的识别.

Characteristic signal analysis and its identification of typical weld penetration status in laser welding

A self-made real-time monitoring system with multiple sensors was applied to acquire audible sound,ultravilot and infrared emission signals in laser welding process.Wedge plates and stepped plates were designed for experiments;RMS,STFT and characteristic frequency-band analysis were used to process signals.It had been found that: the RMS value and the intensity of characteristic frequency band of both audible sound and ultravilot emission are extremely low in the case of excessive penetration;they are much higher when full penetration occurs;for partial penetration,they are distinguishably between the former two statuses.Unstable penetration is noted for its surging signals which are lower than those of full penetration status.Consequently,four distinct penetration statues can be classified obviously.