A Vision-Based Technique for Lay Length Measurement of Metallic Wire Ropes

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The lay length of metallic wire ropes is an important dimensional quantity whose analysis is useful to highlight rope deformations due to distributed damages. This paper describes a measurement system that is based on a video camera and on an offline processing algorithm. The camera acquires an image sequence of the running rope; then, an image processing algorithm extracts the rope contour and measures both the distance among rope strands and the whole distance covered by the rope during the test. A mathematical model of the rope contour has been developed and employed to test the proposed algorithm with simulated data. Field tests have been carried out with the proposed system on a working aerial cableway using a general-purpose camera. </para>