短路过渡电弧的Lyapunov指数分析

为了更好地理解短路过渡气体保护电弧焊的不稳定性,尝试用混沌理论研究这一现象.介绍了A.Wolf理论和相空间重构理论,论述了用于选择重构参数的改进虚假邻近点法和重构信号强度法.利用这些相关的混沌理论及算法,对较稳定和不稳定的两组电流波形数据的最大Lyapunov指数(LE)进行了计算与分析.结果表明:短路过渡电弧是一个复杂的混沌过程,且随着电弧的不稳定性增加,该过程的混沌性增加;最大LE可用于表征短路过渡电弧的稳定性.

Lyapunov exponent analysis of short circuit arc in GMAW

In order to understand the instability of Short circuit Gas Metal Arc Welding(GMAW-S) better,investigation on the stability based on chaos theory is suggested.The A.Wolf theory and state space reconstruction theory are introduced.The methods of revised false nearest neighbors(RFNN) and reconstruction signal strength(RSS) used to select reconstruction parameters are described.By this theories and methods about chaos,the largest Lyapunov Exponent(LE) of two series of practical arc current data with better stability and instability are calculated and analyzed.The results show that the GMAW-S is a complex chaos process,and the chaos increases evidently with the process stability going worse,and the largest LE can be a criterion of the stability of the short circuit arc.