3D machine vision system for inspection of contact strips in railway vehicle current collectors

Construction and technical condition of current collectors is crucial to reliability and safety of railway transportation. According to the Technical Specifications for Interoperability railway vehicles in the European Union should be equipped with carbon contact strips. Excessive wear or defects of contact strips degrade the capability of undisturbed power transmission, cause faster wear of contact wire, and can even result in catenary rupture. The technical condition of contact strips is assessed manually during periodical services performed by rolling stock operators. However, rail infrastructure companies are also interested in pantographs inspection of the vehicles running within their network. A novel inspection system for current collectors contact strips is presented. The system uses a specialized camera and a laser line generator to scan the contact strips surface. The scanning is performed on a railway line, when a vehicle passes the inspection point. A prototype of the system was tested in the target conditions and sample scanning results were recorded. Basic algorithms for automatic analysis of contact strips wear were introduced. Accuracy and repeatability of the measurement were assessed. The potential of commercial implementation of the system was confirmed.