sensors Article Identification and Localization of Track Circuit False Occupancy Failures Based on Frequency Domain Reflectometry Tiago A. Alvarenga 1 , Augusto S. Cerqueira 1 , Luciano M. A. Filho 1 , Rafael A. Nobrega 1 , Leonardo M. Honorio 1,* and Henrique Veloso 2 1 Electrical Engineering Department, Federal University of Juiz de Fora, Juiz de Fora 36036-900, MG, Brazil;
[email protected] (T.A.A.);
[email protected] (A.S.C.); luciano.ma.fi
[email protected] (L.M.A.F.);
[email protected] (R.A.N.) 2 MRS Logística, Juiz de Fora 36060-010, MG, Brazil;
[email protected] * Correspondence:
[email protected] Received: 15 October 2020; Accepted: 9 December 2020; Published: 18 December 2020 Abstract: Railway track circuit failures can cause significant train delays and economic losses. A crucial point of the railway operation system is the corrective maintenance process. During this operation, the railway lines have the circulation of trains interrupted in the respective sector, where traffic restoration occurs only after completing the maintenance process. Depending on the cause and length of the track circuit, identifying and solving the problem may take a long time. A tool that assists in track circuit fault detection during an inspection adds agility and efficiency in its restoration and cost reduction. This paper presents a new method, based on frequency domain reflectometry, to diagnose and locate false occupancy failures of track circuits. Initially, simulations are performed considering simplified track circuit approximations to demonstrate the operation of the proposed method, where the fault position is estimated by identifying the null points and through non-linear regression on signal amplitude response.