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Active suspension in trains


Sources of funding

  • Banverket/Trafikverket


Photo: Bombardier Transportation
The Regina test train

In rail operation today, the general trend is aiming towards increased vehicle speeds. However, higher speeds usually generate increased forces and accelerations on the vehicle, which has a negative impact on ride comfort. This problem can be dealt with, for instance, by implementing active technology in the secondary suspension, resulting in maintained or even improved passenger comfort. It may also be a way to maintain good ride comfort when running on tracks of inferior quality. The project is part of the research and development programme Gröna Tåget.


The purpose of this research project is to develop a system of active secondary suspension – laterally and vertically – for the next generation of high-speed trains in Sweden. The system must enable maintained or even improved ride comfort, even when speed is increased from 200 to 250 km/h, and even when the track standard is the same.

Research Direction

Active suspension
Measurement result from a track section with small-radius curves

In the first phase of the project, focus is on active secondary suspension in the lateral direction. Dynamic vibration control is used to reduce lateral vibrations in the carbody, and hence improve ride comfort. Furthermore, lateral quasi-static control (Hold-Off Device) is applied in order to centre the carbody above the bogies in curves. The carbody centring enables a wider carbody profile and cross wind stability is improved. Also, higher speed in curves can be allowed, which reduces travel times.

After design studies with help of computer simulation, on-track tests have been performed with an active lateral secondary suspension concept implemented in a two-car Regina train. The evaluated measurement results are encouraging and the device has been implemented in long-term tests in service operation. A Regina train with active lateral secondary suspension has been operating since March 2009.

In the second phase of the project, focus is on improving ride comfort in the vertical direction by means of active secondary suspension. Ride comfort is improved by means of dynamic vertical control. Furthermore, vertical quasi-static control enables carbody tilting in curves. This means that higher speeds are possible without negatively affecting ride comfort.


  • Orvnäs A: On Active Secondary Suspension in Rail Vehicles to Improve Ride Comfort, Doctoral Thesis, Rail Vehicles, KTH, TRITA AVE 2011:79, ISBN 978-91-7501-155-4, Stockholm, Sweden, 2011.
  • Orvnäs A, Stichel S and Persson R: Aspects of using active vertical secondary suspension to improve ride comfort. Proceedings of the 22nd International Symposium on Dynamics of Vehicles on Roads and Tracks, IAVSD'11, Manchester, August 14-19, 2011.
  • Orvnäs A, Stichel S and Persson R: Active lateral secondary suspension with Hinf control to improve ride comfort: simulations on a full-scale model. Vehicle System Dynamics, Vol. 49, No. 9, pp. 1409-1422, 2011.
  • Orvnäs A, Stichel S and Persson R: Ride comfort improvements of a REGINA train with active lateral secondary suspension. Proc. of the 8th International Conference on Railway Bogies and Running Gears, BOGIE’10, Budapest, Hungary, September 13-16, 2010.
  • Orvnäs A: Methods for reducing vertical carbody vibrations of a rail vehicle – a literature survey. Publ. 1002, ISBN 978-91-7415-631-7, KTH Railway Group, Stockholm, Sweden, 2010. 
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  • Orvnäs A, Stichel S and Persson R: Development and test of active secondary suspension in a rail vehicle. Proc. of the 21st International Symposium on Dynamics of Vehicles on Roads and Tracks, IAVSD’09, Stockholm, Sweden, 17-21 August, 2009.
  • Orvnäs A, Stichel S and Persson R: Ride comfort improvements in a high-speed train with active lateral suspension. Proc. of the International Symposium on Speed-Up, Safety and Service Technology for Railway and Maglev Systems, STECH’09, Niigata, Japan, 16-19 June, 2009. Also in Journal of Mechanical Systems for Transportation and Logistics (JSME), Vol. 3, No. 1, pp. 206-215, 2010. 
  • Orvnäs A: Active lateral secondary suspension in a high-speed train to improve ride comfort. Licentiate Thesis, TRITA AVE 2009:22, ISBN 978-91-7415-300-2, KTH Rail Vehicles, 2009.
  • Orvnäs A: Active secondary suspension in trains – a literature survey of concepts and previous work. Publ 0803, ISBN 978-91-7415-144-2, KTH Railway Group, 2008. 
  • Orvnäs A, Stichel S and Persson R: On-track tests with active lateral secondary suspension: a measure to improve ride comfort. ZEVrail Glasers Annalen 132, No 11-12, pp. 469-477, 2008.