The work of the European Committee for Standardization (CEN), Working Group CEN/TC256/WG7, concerns ride comfort for passengers. A European prestandard from 1999 for the measurement and evaluation of ride comfort for rail passengers has been revised by the working group. A draft standard prEN 12299 (Railway applications -Ride comfort for passengersMeasurement and evaluation) was sent for enquiry during 2006. From the CEN members, the national standardisation bodies of 28 countries, more than 300 technical and editorial comments were received. WG7 then produced a revised draft standard, which in 2009 was accepted as a European standard. The present conference paper discusses certain parts of EN 12299:2009, with a focus on data processing, the application of computer methods and interpretation of results.

Many railways have taken tilting trains into operation on lines with horizontal curves with small radii. Tilting trains have vehicle bodies that can roll inwards, thus reducing the lateral acceleration perceived by the passengers. Hence, tilting trains can run through curves at an enhanced speed. However, too much tilt can cause motion sickness among sensitive passengers. The tilt motions, generated by computer-controlled actuators should be optimised with care, taking the local track geometry and actual train speed into account. This paper presents tilt algorithms aimed at balancing conflicting objectives. Furthermore, the paper discusses the usefulness of route files (track geometry data) onboard the train and possible positioning systems.

Many railways have put tilting trains into operation on lines with horizontal curves with small radii. Tilting trains have vehicle bodies that can roll inwards, reducing the lateral acceleration perceived by the passengers. Tilting trains can therefore run through curves at higher speeds. However, excessive tilt motions can cause motion sickness in sensitive passengers. On the other hand, too little tilting will cause discomfort from high lateral acceleration and jerk.The present paper presents new tilt algorithms aimed at balancing the conflicting objectives of ride comfort and less motion sickness. An enhanced approach is taken, where the amount of tilt depends on the local track conditions and the train speed. The paper shows how selected tilt algorithms influence certain motion sickness related carbody motions.Speed profiles designed to avoid local peaks in the risk of motion sickness are another possibility. The speed profiles for both tilting and non-tilting trains are today set from safety and comfort perspectives only, thus minimizing the running time. The present paper shows how speed profiles could be used to balance the conflicting objectives of running time and less risk of motion sickness. The result is derived from simulations and put in relation to today's tilt algorithms and speed profiles on the Stockholm-Gothenburg main line in Sweden (457 km).

Carbody tilting is today a mature and inexpensive technology that permits higher train speeds in horizontal curves, thus shortening travel time. However, tilting trains run a greater risk of causing motion sickness than non-tilting ones. It is likely that the difference in motions between the two train types contributes to the observed difference in risk of motion sickness. Decreasing the risk of motion sickness has until now been equal to increasing the discomfort related to quasi-static lateral acceleration. But, there is a difference in time perception between discomfort caused by quasi-static quantities and motion sickness, which opens up for new solutions. One proposed strategy is to let the local track conditions influence the tilt and give each curve its own optimised tilt angle. This is made possible by new tilt algorithms, storing track data and using a positioning system to select the appropriate data. The present paper reports from on-track tests involving more than 100 test subjects onboard a tilting train. A technical approach is taken evaluating the effectiveness of the new tilt algorithms and the different requirements on quasi-static lateral acceleration and lateral jerk in relative terms. The evaluation verifies that the rms values important for motion sickness can be influenced without changing the requirements on quasi-static lateral acceleration and lateral jerk. The evaluation shows that reduced quantities of motions assumed to have a relation to motion sickness also lead to a reduction in experienced motion sickness. However, a limitation of applicability is found as the lowest risk of motion sickness was not recorded for the test case with motions closest to those of a non-tilting train. An optimal level of tilt, different from no tilt at all, is obtained. This non-linear relation has been observed by other researchers in laboratory tests.