用Lyapunov指数研究点焊位移信号的混沌特性

基金项目: 国家自然科学基金资助项目(50575159);教育部博士点基金资助项目(20030056003);天津市应用基础研究计划项目(06YFJMJC03400)

Chaos characteristics of electrode displacement signals in spot welding process based on Lyapunov exponent

School of Material Science and Engineering, Tianjin University, Tianjin 300072, China

摘要: 文中以混沌理论为基础,阐述了Lyapunov指数作为点焊位移时间序列的混沌判断原理,并对电阻点焊位移信号中进行了分析与研究,计算了4种不同工作状态下点焊位移信号时间序列的Lyapunov指数,研究表明,点焊位移信号中的最大Lyapunov指数均大于0,根据混沌理论可以断定点焊位移信号中存在混沌现象,应该采用混沌的方法研究与分析点焊位移信号,该研究为点焊质量的判断和预测开辟了新的途径。
- 点焊 /
- 电极位移信号 /
- Lyapunov指数 /
- 混沌时间序列
Abstract: Based on chaos theory and the nonlinear dynamical systems, the electrode displacement signal was studied in the spot welding process.Four quality states of spot welding were studied and the largest Lyapunov exponents are calculated.These results show that the greatest Lyapunov exponents are positive number in the four different displacement signals. According to the theory of phase space reconstruction and Lyapunov exponent, there are some chaotic characteristics in the displacement signal of spot welding and relationships between spot welding quality and Lyapunov exponent.This research provides a new method to measure and forecasting the spot welding quality.
- spot welding /
- electrode displacement signals /
- Lyapunov exponent /
- chaos time series