Contact force signal analysis of current collecting with bispectrum and wavelet

Contact force between pantograph and contact wire always changes due to the vibration of train and pantograph by corrugated wear and height change of contact wire. This paper presents contact force signal analysis by bispectrum and continuous wavelet transform. Bispectral estimates of contact force signal show that a few harmonic signals exist. Those are thought changes in contact force generated by height change and vibration of contact wire among support points, droppers and hangers. The continuous wavelet transform (CWT) with mother wavelet based on harmonic signal in contact force signal is performed, thus the possibility of fault detection of the wire by CWT is shown.