Diagnostic process of the pantograph current-collector through an acoustic method

In a railway system, trains get electricity through a structure mainly composed by contact wires and pantographs. The electricity runs through contact wire, a fixed wire suspended above railway tracks. Trains make contact with the wire and get the electricity that runs along the contact wire by means of a pantograph. In a railway system, a pantograph is a device fixed on the top of a train that reaches upwards towards the contact wire suspended above the train and creates the necessary contact between train and wire carrying electricity. The end part of the pantograph that touches the contact wire is known as contact strip line. But if the surface of a contact strip line is not smooth, contact between pantograph and suspended contact wire you get vibrations, generally a frequency of thousands of Hz with constant time damping of few hundred seconds. These vibrations give rise to acoustic signals that can be picked up by microphones mounted along the track. The acoustic signal is filtered to a range of thousands of hertz using a specific data signal process. At this point a special device is used to analyse the signal and determine the roughness of the contact strip line that caused the vibrations. Different experiments have been carried out to understand the specific parameters of the acoustic signal, the results tell us how rough a contact strip line actually is. The application of this method, to detect any defects in the pantograph, like undesired contact strip line roughness, is original.