Low speed lifting cable diagnosis using instantaneous angular speed

This paper describes an experimental study of lifting cable fault diagnostic based on instantaneous angular speed (IAS) technique. During the study load tests on a selection of damaged cables, it is shown that IAS increases significantly after the damage is inflicted. The relationship between IAS signal characteristics and strand defects is investigated and it is found that the most influent parameters over IAS are speed, load and defects size. The pattern of IAS signals during a detection fault test is studied and a suggestion is made for a filtering technique to improve the recognition of imminent failure. Finally, an evaluation of the common statistical indicators was implemented. The study gave satisfactory results and shown that IAS measurement is a promising tool for the health monitoring of low speed cables.