Bustos Caballero, AlejandroRubio Alonso, HiginioCastejón Sisamón, CristinaGarcía Prada, Juan Carlos2021-11-302021-11-302021-12Bustos, A., Rubio, H., Castejon, C. & Garcia‐Prada, J. C. (2021). Enhancement of chromatographic spectral technique applied to a high‐speed train. Structural Control and Health Monitoring, 28(12), e2842.1545-2263https://hdl.handle.net/10016/33715High-speed rail is a key player in people's mobility thanks to its speed and high safety standards. These high safety standards are supported by extensive maintenance (of both rolling stock and track) that applies the latest nondestructive and monitoring techniques. In that context, this work presents the enhanced graphical representation of state configurations (EGRSC) and enhanced chromogram of bands of frequency (ECBF) methods, which are the evolution of the graphical representation of State configurations and chromogram of bands of frequency techniques. A clearer nomenclature is defined for the configuration states of the EGRSC. The ECBF introduces a new variable threshold that allows discarding frequency regions with small power variations and a new color palette. These methods are used in the vibratory study of an in-service high-speed train to identify the operating condition of the train. To conduct that task, a set of accelerometers is installed on the axle box of a trailer axle of the train. Accelerometers are oriented into the three space directions: longitudinal, lateral, and vertical. Vibration signals are taken during the normal operation of the train and transmitted to and stored on a remote database. Vibration measures are collected before and after a major maintenance operation. The application of EGRSC and ECBF allows collecting information from thousands of vibration signals and to display that information intuitively and understandably. The analysis of EGRSC and ECBF results allows identifying several frequency regions with significant spectral power variations that are common to the three vibration directions studied. These patterns should be taken as a reference for future maintenance actions. Any unexpected behavior of these frequency regions would indicate the presence of a fault.20eng© 2021 The Authors. Structural Control and Health Monitoring published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.Atribución-NoComercial-SinDerivadas 3.0 EspañaECBFEGRSCHigh-speed railMaintenanceresearch articleIngeniería Mecánicahttps://doi.org/10.1002/stc.2842open accesse284212Structural Control & Health Monitoring28AR/0000028438