%0 Thesis
%9 Doctoral
%A Sengupta, Monish
%B Civil, Environmental & Geomatic Engineering
%D 2024
%E Heydecker, Benjamin
%F discovery:10197711
%I UCL (University College London)
%K Railway, sensor fusion, ERTMS, CBTC, Kalman filter
%P 312
%T Location and speed estimation for telematic signalling in  railways
%U https://discovery.ucl.ac.uk/id/eprint/10197711/
%X This study considers the relationship between railway capacity and signalling  systems. To increase railway capacity, signalling has been increased from two  to four aspects, which can accommodate a maximum of 35 trains per hour.  Although aspect signalling relies on fixed block control, the introduction of  a moving block signalling system could achieve a capacity of 44 trains per  hour. Achieving this would involve the introduction of telematic signalling  systems (ERTMS and CBTC), which depend on the continuous and accurate  measurement of the train location and speed. The current stopping accuracy  required for a train is ± 1m on Britain’s mainline railway and ± 0.5m for London  Underground. This is attributed mostly to the sensor fusion framework  that is currently in place to obtain accurate train location and speed. In this  thesis, a framework is developed based on the Kalman filter. This research  shows that a linear Kalman filter fusing data from railway sensors such as  Doppler radar, tachometers and wayside balise can provide good estimates of  train location and speed. However, an unscented Kalman filter is capable of  achieving more than four times better accuracy. The performance of these  filters is investigated in the presence of wheel slip and slide, and instances of  missing balise, leading to reduced capacity. In order to counter this, two adaptive  sensor fusion frameworks are developed based on Magill’s filter bank and  innovation tracking. Both are applied to linear and unscented Kalman filters  which shows improved state estimation and stopping accuracy, hence capacity.  Analysis shows that balise placement on the approach to the stopping point is  important. Numerical results show that interception of a single balise reduces  the location error well within the required range. Therefore, a maximum of  two balises will serve the purpose with one as a backup.
%Z Copyright © The Author 2024. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/).  Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms.  Access may initially be restricted at the author’s request.