Dynamic Rail Inspection by Vision System

Abstract

Current in-field rail track ultrasonic inspection technologies, requiring contact between the probes and the rail surface, show limitations as defect detection is affected by rail surface condition, rail head geometry and defect geometry and orientation. Moreover, inspection speeds are moderate. To improve rail flaw detection, the partnership of the U-Rail project - within the sixth EU framework programme - proposes a new non-contact ultrasonic inspection system, consisting of a pulsed laser and air-coupled transducers. For a proper positioning, the inspection unit includes a laser optic triangulation unit and an automatic positioning system. The first determines the position of the rail, processes the data and drives the positioning system. The U-Rail system allows high speed inspection of the complete rail section. The paper describes the system and results of research activities of two U-Rail partners.