Abstract:

Chaotic theory and phase reconstruction were used to analyse signal time series of current during spot welding, and some indexes such as optimal delay time τ, correlation dimension D, embedding dimension m, and Lyapunov exponent were obtained, and chaotic properties were verified in this series sometimes. And the number of influencing factor was discussed. At last, the largest forecasting scale on the signal series time of spot welding current was estimated. And it gives a reference to the research of quality detection and controlling system.

Key words: spot welding, chaotic time series, correlation dimension, the largest Lyapunov exponent

摘要：

以混沌理论和相空间重构理论为基础对点焊焊接过程中电流信号的时间序列进行了特征分析，分别对电流信号时间序列的最佳时间延迟τ、关联维数D、嵌入维数m及最能体现混沌特征的Lyapunov指数进行了定量化的计算，发现点焊焊接过程中电流信号在某些情况下具有混沌特征。分析了影响电流信号的因素个数，给出了混沌意义上的最大电流信号时序的预测尺度。研究结果为进一步结合统计理论改进点焊质量检测和控制系统提供了参考。

关键词: 点焊, 混沌时间序列, 关联维数, 最大Lyapunov指数