B-spline approach for failure detection and diagnosis on railway point mechanisms case study

In railway transportation the safety and reliability in operations of railway point mechanism must be ensured in order to improve the quality of the service. This article presents a case study in a railway turnout (U.S.: switch). The case study reports how the effect of the operating force data sampled and monitored during the switching of a railway point mechanism can be converted into continuous polynomial B-spline functions. These functions are employed to define, and periodically to update, tolerance bands for the purpose of condition monitoring. Data from variously faulty mechanisms were converted similarly, and the profiles found to differ sufficiently not only to detect 100 percent of faults but, from the distinctive shapes of the profiles, to diagnose (i.e., distinguish correctly between) some 70-80 percent of them.