Carbody tilt without motion sickness

Researchers

Sources of funding

Banverket/Trafikverket, Bombardier Transportation, SL AB, Tågoperatörerna, Interfleet Technology, Vinnova, VTI.

Background

Carbody tilting

Carbody tilting is today a mature and inexpensive technology that allows higher speeds on curves, thus shortening travel time. The technology has been accepted by many train operators, but some issues are still holding back the full potential of tilting trains. Motion sickness is one of these issues, as tilting trains generally cause more motion sickness than non-tilting ones. The difference as regards risk of motion sickness between non-tilting and tilting rolling stock has even been subject of an EU-funded research project named Fast and Comfortable Trains.

Objective

The purpose of this research project is to seek the source to the risk of motion sickness experienced on tilting trains and to suggest measures to reduce the risk. The task is taken in a technical point of view, aiming at solutions possible to introduce in the next generation of tilting trains.

Research Direction

Finding and describing the motion difference between tilting and non-tilting trains was the first step in the project. Evaluation of earlier on-track tests with subjects was made to correlate motions to experienced motion sickness.

The second step was to find solutions that could influence the motion with relation to motion sickness. Actions like better control of the carbody motion, local speed restrictions and less tilting were suggested and studied. A new tilt algorithm was developed to meet the counteracting requirement of good ride comfort and low risk for motion sickness. The idea was to calculate the best possible tilt angle for each curve before entering the curve and use this information to control the tilt. This is made possible by storing track geometry data onboard the train and use a positioning system to pick the appropriate data at the right time. Two other advantages with the use of stored track geometry rather than measure quantities while running as base for the tilt control are the absence of influence from track irregularities and the correct timing; see figure.

The third step was to prove the effectiveness on the algorithm at on-track tests with subjects. The on-track tests became a technical success; closer evaluation will show what influence the algorithms had on motions and motion sickness.

Measured and track data based tilt reference
Measured and track data based tilt reference

Publications

  • Persson R: Tilting trains – Enhanced benefits and strategies for less motion sickness. Doctoral Thesis, Report TRITA AVE
    2011:26, KTH Rail Vehicles, 2011. ISBN 978-91-7415-948-6.
  • Persson R, Kufver B: Strategies for less motion sickness on tilting trains, Proceedings of Comprail 2010, pp 581-591. WIT Press, Southampton 2010.
  • Persson R: Tilting trains - benefits and motion sickness, Proc. IMechE Journal of Rail and Rapid Transit, Vol 224, pp 513-522, November 2010.
  • Persson R: Weighting curves to motion sickness, Proc of the 44th UK Conference on Human Response to Vibration, Loughborough 2009.
  • Persson R, Goodall R M and Sasaki K: Carbody tilting - Technologies and benefits. State-of-the-Art Paper of the 21st
    IAVSD Symposium, Vehicle System Dynamics, Vol 47, No 8, pp. 949-981, August 2009.
  • Persson R: Motion sickness on-track test evaluation, Proc of the 43rd UK Conference on Human Response to Vibration, Leicester 2008.
  • Persson R: Motion sickness in tilting trains, Proc of the 43rd UK Conference on Human Response to Vibration, Leicester 2008.
  • Persson R: Tilting trains – Technology, benefits and motion sickness. Licentiate Thesis, Report TRITA AVE 2008:27, KTH
    Rail Vehicles, 2008. ISBN 978-91-7178-972-3.
  • Persson R: Motion sickness in tilting trains – Description and analysis of the present knowledge. Publ 0801, KTH Railway
    Group, 2008. ISBN 978-91-7178-680-3.
  • Persson R: Åksjuka i korglutande tåg. Transportforum, Linköping 2008.
  • Persson R: Korglutning - behövs det? Nordic Rail, Jönköping, October 2007.
  • Persson R: Research on the competitiveness of tilting trains, Proc of Railway Engineering 2007, Engineering Technical Press, Edinburgh 2007.
  • Persson R: Identification of areas where the competitiveness of tilting trains can be further improved, Proc of Railway
    Engineering 2007, Engineering Technical Press, Edinburgh 2007.
  • Persson R: Tilting Trains – A description and analysis of the present situation. Publ 0702, KTH Railway Group, 2007. ISBN
    978-91-7178-608-1.
  • Persson R: Spårvänliga boggier och korglutning, Transportforum 2007.
  • Kufver B and Persson R: On enhanced tilt strategies for tilting trains, Proceedings of Comprail 2006, pp 839-848. WIT Press, Southampton 2006.