Chaotic oscillator detection system about weak signals in spot welding

Abstract

Spot welding is an efficient and shortcut processing method used in plate, and its quality detection is very important. However, there are many factors affecting the spot welding quality. Because of the low precision of traditional detection methods, spot welding has seldom been used in the aerospace industry which requires high welding quality. In this article, we give a new weak signal detection model based on chaotic oscillators. Using Melnikov methods and Lyapunov exponent, we can determine the critical values when the system enters in and out of chaos. Through lots of numerical simulations, it can be found that the lowest value of the weak sinusoidal signal the system can detect reach 10^-11, and its signal-to-noise ratio (SNR) is -126 dB. Compared with other detection methods, chaos oscillator detection system not only has a lower threshold value, but also is easy to implement in practice. This model thus has good application prospects.

Keywords

spot welding / chaotic oscillators / Duffing equation / signal-to-noise ratio (SNR)

References

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Acknowledgements

The authors wish to thank the financial support for this research from the National Natural Science Foundation of China (Grant No. 50575159), the Project of Chinese Ministry of Education (Grant No. 106049, 20060056058), the Natural Science Foundation of Tianjin (06YFJMJC03400), and the Natural High-Tech R&D 863 Program (2008AA04Z136).

RIGHTS & PERMISSIONS

2014 Higher Education Press and Springer-Verlag Berlin Heidelberg