An Analysis-by-Synthesis Approach to Rope Condition Monitoring

A regular rope quality inspection is compulsory for wire ropes in security-relevant applications. Principal procedures of such quality checks are the visual inspection for surface defect detection, the magnetic inspection for a localization of broken wires and the measurement of the rope diameter. However, until today it is hardly possible for the human inspector to measure other important rope characteristics as the lay length of wires and strands over time. To close this gap, we present a model-based approach for rope parameter estimation. The usage of a theoretically correct and regular 3d rope, embedded in an analysis-by synthesis framework, allows a purely image-based monitoring of important rope parameters. Beyond that, also a quantification of the degree of abnormality becomes possible. Our evaluation on real-world and synthetic reference data demonstrates that the approach allows a measurement of the individual lay lengths of wires and strands up to an accuracy more precise than 1 mm.