FPGA implementation of time-frequency analysis algorithms for laser welding monitoring

The on-line monitoring and detection of defects in laser welding is a basic manufacturing requirement in several applicative contexts, as vehicle assembly in automotive production. This work presents the FPGA implementation of time-frequency analysis algorithms as an effective solution compared with pure software implementation based on different modern processors. In particular the proposed FPGA based approach not only satisfies the processing constraints of the considered application, but still offers a high degree of flexibility and modularity.

[1]  L. Cohen,et al.  Time-frequency distributions-a review , 1989, Proc. IEEE.

[2]  V. Piuri,et al.  Composite techniques for quality analysis in automotive laser welding , 2003, The 3rd International Workshop on Scientific Use of Submarine Cables and Related Technologies, 2003..

[3]  E. Wigner.  On the quantum correction for thermodynamic equilibrium , 1932 .

[4]  Yong Wang,et al.  Sensing and control system of process quality in CO2 laser deep-penetration welding , 1998, Other Conferences.

[5]  Dennis Gabor,et al.  Theory of communication , 1946 .

[6]  D. Farson,et al.  Relationship of optical and acoustic emissions to laser weld penetration , 1998 .

[7]  Patrizia Sforza,et al.  On-line optical monitoring system for arc welding , 2002 .

[8]  Hongping Gu,et al.  Resonant acoustic emission during laser welding of metals , 1996 .

[9]  Yong Yan,et al.  Automated Inspection of Micro Laser Spot Weld Quality Using Optical Sensing and Neural Network Techniques , 2006, 2006 IEEE Instrumentation and Measurement Technology Conference Proceedings.

[10]  Ingrid Daubechies,et al.  Ten Lectures on Wavelets , 1992 .

[11]  Helmut Huegel,et al.  Laser beam welding: recent developments on process conduction and quality assurance , 1999, Other Conferences.

[12]  Yimin Zhang,et al.  Blind Separation of Nonstationary Sources Based on Spatial Time-Frequency Distributions , 2006, EURASIP J. Adv. Signal Process..

[13]  J.B. Allen,et al.  A unified approach to short-time Fourier analysis and synthesis , 1977, Proceedings of the IEEE.

[14]  W M. Steen,et al.  Monitoring Of Laser Material Processes , 1986, Other Conferences.

[15]  F. Hlawatsch,et al.  Linear and quadratic time-frequency signal representations , 1992, IEEE Signal Processing Magazine.

[16]  J. Tukey,et al.  An algorithm for the machine calculation of complex Fourier series , 1965 .

[17]  Ho-Young Jung,et al.  On the Efficient Speech Feature Extraction Based on Independent Component Analysis , 2002, Neural Processing Letters.

[18]  Young Whan Park,et al.  Real time estimation of CO2 laser weld quality for automotive industry , 2002 .

[19]  Lin Li,et al.  A Comparative Study of Ultrasound Emission Characteristics in Laser Processing , 2002 .

[20]  Sehun Rhee,et al.  Estimation of weld bead size in CO2 laser welding by using multiple regression and neural network , 1999 .

[21]  Dave F. Farson,et al.  Generation of optical and acoustic emissions in laser weld plumes , 1999 .

[22]  T. Claasen,et al.  THE WIGNER DISTRIBUTION - A TOOL FOR TIME-FREQUENCY SIGNAL ANALYSIS , 1980 .