{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T20:50:52Z","timestamp":1777927852569,"version":"3.51.4"},"reference-count":14,"publisher":"SAGE Publications","issue":"3","license":[{"start":{"date-parts":[[2013,11,19]],"date-time":"2013-11-19T00:00:00Z","timestamp":1384819200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit"],"published-print":{"date-parts":[[2015,3]]},"abstract":"<jats:p>With the increases in traffic, axle loads and travelling speed, the dynamic monitoring of railway tracks and structures is becoming more and more important to ensure a high level of safety and comfort. This situation is particularly critical at transition zones where rapid changes of track stiffness occur. This paper presents a contactless system to measure track displacements and its application in an embankment\/underpass transition zone, located on the Northern line of the Portuguese railway network where the Alfa Pendular tilting train travels at a maximum speed of 220\u2009km\/h. The system is based on a diode laser module and a position sensitive detector (PSD). The PSD receives the laser beam emission and the detection of the centre of gravity of the beam spotlight on the PSD area enables the calculation of the displacement. Before field application, static and dynamic laboratory validation tests were performed in order to evaluate the system performance for different laser to PSD distances, and an accuracy of 0.01\u2009mm was achieved using data acquisition rates of up to 15\u2009kHz. The optical measuring system proved to be an efficient and flexible way to measure absolute and relative rail displacements in the field, enabling the detection of track deformability differences along the transition zone, even for the passage of trains at high speed (220\u2009km\/h).<\/jats:p>","DOI":"10.1177\/0954409713509980","type":"journal-article","created":{"date-parts":[[2013,11,19]],"date-time":"2013-11-19T21:36:08Z","timestamp":1384896968000},"page":"280-290","update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":27,"title":["Dynamic monitoring of railway track displacement using an optical system"],"prefix":"10.1177","volume":"229","author":[{"given":"Nuno","family":"Pinto","sequence":"first","affiliation":[{"name":"FEUP \u2013 Faculty of Engineering, University of Porto, Portugal"},{"name":"CEC \u2013 Centro de Estudos da Constru\u00e7\u00e3o, FEUP, Porto, Portugal"}]},{"given":"Cristina Alves","family":"Ribeiro","sequence":"additional","affiliation":[{"name":"FEUP \u2013 Faculty of Engineering, University of Porto, Portugal"},{"name":"CEC \u2013 Centro de Estudos da Constru\u00e7\u00e3o, FEUP, Porto, Portugal"}]},{"given":"Joaquim","family":"Gabriel","sequence":"additional","affiliation":[{"name":"FEUP \u2013 Faculty of Engineering, University of Porto, Portugal"},{"name":"IDMEC \u2013 Polo FEUP, Porto, Portugal"}]},{"given":"Rui","family":"Cal\u00e7ada","sequence":"additional","affiliation":[{"name":"FEUP \u2013 Faculty of Engineering, University of Porto, Portugal"},{"name":"CEC \u2013 Centro de Estudos da Constru\u00e7\u00e3o, FEUP, Porto, Portugal"}]}],"member":"179","published-online":{"date-parts":[[2013,11,19]]},"reference":[{"key":"bibr1-0954409713509980","unstructured":"Berggren E.\n                      Railway track stiffness. Dynamic measurements and evaluation for efficient maintenance.\n                      PhD Thesis, Royal Institute of Technology, Sweden, 2009."},{"key":"bibr2-0954409713509980","unstructured":"Fr\u00f6hling RD.\n                      Deterioration of railway track due to dynamic vehicle loading and spatially varying track stiffness.\n                      PhD Thesis, University of Pretoria, South Africa, 1997."},{"key":"bibr3-0954409713509980","unstructured":"European Rail Research Institute.\n                      State of the art report\n                      ,\n                      bridge ends, embankment structure transition\n                      . Report D230.1\/RP3, 1999. Utrecht, Netherlands: European Rail Research Institute."},{"key":"bibr4-0954409713509980","unstructured":"L\u00f3pez-Pita A. Deterioration of track geometric quality on high speed lines: the experience of the Madrid - Seville line. In:\n                      The workshop on track for high-speed railways\n                      , (eds Am\u00e9rico Pires da Costa, Ant\u00f3nio Campos e Matos, Ant\u00f3nio Fidalgo do Couto, Cec\u00edlia Vale and Rui Cal\u00e7ada), FEUP, Porto, Portugal, 12\u201313 October 2006, pp.181\u2013195. Porto, Portugal: FEUP."},{"key":"bibr5-0954409713509980","doi-asserted-by":"publisher","DOI":"10.1016\/j.compstruc.2011.02.013"},{"key":"bibr6-0954409713509980","doi-asserted-by":"publisher","DOI":"10.2478\/v10174-010-0009-y"},{"key":"bibr7-0954409713509980","doi-asserted-by":"publisher","DOI":"10.1016\/S0022-460X(03)00725-9"},{"key":"bibr8-0954409713509980","doi-asserted-by":"publisher","DOI":"10.1243\/0954409JRRT51"},{"key":"bibr9-0954409713509980","unstructured":"Hendry M, Hughes D, Barbour L, et\u00a0al. Measuring and modelling the train induced dynamic response of a railway track and embankment constructed over a soft peat foundation. In:\n                      The sixth international conference on railway track foundations\n                      (eds GS Ghataora and MPN Burrow), Birmingham, UK, 11\u201313 September 2006, pp. 274\u2013282. Birmingham, UK: University of Birmingham Press."},{"key":"bibr10-0954409713509980","unstructured":"INNOTRACK.\n                      Methods of track stiffness measurements.\n                      Report D2.1.11, 2006."},{"key":"bibr11-0954409713509980","unstructured":"SUPERTRACK.\n                      Instrumentation, monitoring and physical modelling of high-speed line.\n                      Final report, 2005."},{"key":"bibr12-0954409713509980","first-page":"334","author":"Woschitz H","year":"2001","journal-title":"Entwicklung eines optischen messsystems f\u00fcr die bestimmung von hochfrequenten zweidimensionalen positions\u00e4nderungen. Allgemeine Vermessungs-Nachrichten"},{"key":"bibr13-0954409713509980","unstructured":"Kay SM. Modern spectral estimation, Englewood Cliffs, NJ: Prentice-Hall, 1988, pp. 453\u2013455."},{"key":"bibr14-0954409713509980","unstructured":"European Rail Research Institute.\n                      Railway bridges for speeds >200\u2009km\/h.\n                      Final report D214\/RP9, 1999. Utrecht, Netherlands: European Rail Research Institute."}],"container-title":["Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/0954409713509980","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/full-xml\/10.1177\/0954409713509980","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/0954409713509980","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T22:54:22Z","timestamp":1777676062000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1177\/0954409713509980"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2013,11,19]]},"references-count":14,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2015,3]]}},"alternative-id":["10.1177\/0954409713509980"],"URL":"https:\/\/doi.org\/10.1177\/0954409713509980","relation":{},"ISSN":["0954-4097","2041-3017"],"issn-type":[{"value":"0954-4097","type":"print"},{"value":"2041-3017","type":"electronic"}],"subject":[],"published":{"date-parts":[[2013,11,19]]}}}