基于Lyapunov指数刻画短路过渡GMAW的稳定性

基于不同焊接速度下短路过渡熔化极二氧化碳气体保护电弧焊的焊接电流时间序列,利用Takens相空间重构技术和Lyapunov指数的Wolf算法,分析评估了焊接系统的最大Lyapunov指数。结果表明,当焊接过程的稳定程度较高时,最大Lyapunov指数较小;而当系统处于不稳定状态、状态变动迅速时,最大Lyapunov指数相应较大;因此最大Lyapunov指数和焊接过程稳定性成负相关关系,可以将其作为刻画短路过渡熔化极二氧化碳气体保护电弧焊稳定性的一种新的量化指标。

Stability of CO2 GMAW with short-circuit transfer based on Lyapunov exponent

Based on the experimental time series of welding current produced by carbon dioxide gas metal arc welding (CO2 GMAW) with short-circuit transfer under different welding speeds, the largest Lyapunov exponents of the welding system are numerically evaluated using Takens' phase space reconstruction technique and the Wolf's algorithm for Lyapunov exponent. The results show that the largest Lyapunov exponent reaches small values when the welding processes approach high steady states. While the system is at the unsteady mode and experiences rapid variation, the largest Lyapunov exponent attains large values. So the largest Lyapunov exponent is negatively correlated with the welding process stability and can be taken as a novel indicator to quantify the process stability of CO2 GMAW with short-circuit transfer.