Non-contact sensor for monitoring catenary-pantograph interaction

This paper presents a sensor system used to measure the height variations of the overhead contact wire feeding electric traction trains when a pantograph is passing. These measures are used to determine the occurrence of defects in the catenary-pantograph interaction. The non-contact sensor for monitoring catenary-pantograph interaction (NCCPI) system consists of a line-scan camera focused to an infrared screen, so that the contact wire is within the viewing plane of the line-scan. The screen is comprised of a light illuminated area and four black areas, which are used as a reference for determining the height of the wire. The measures are taken in differential form, diminishing the effect of vibrations and changes in lighting. The paper shows the mathematical model of the sensor system and the practical results obtained.