During the last 10 years, tilt technology has progressed from unproven technology to a commercial success. However, not all the technical challenges have yet been solved and a numer of the potential benefits of tilting trains remain to be exploited. This presentation is aimed at providing an update on recent Swedish research. The research has been conducted with full-scale train tests and tests with a vehicle simulator capable of generating different combinations of lateral and roll motions. These experiments with students as test subjects were focused on ride comfort and motion sickness as functions of the motion environment. The tests were also aimed at finding a better tilt control strategy for a tilting train. Other experiments were conducted through computer simulations of vehicle reactions. Tilting and non-tilting trains were simulated on different track geometries, in order to define the best alignment and cant with respect to passenger comfort and wheel/rail forces. The results from the test subjects show that provocation of motion sickness is highly dependent on the net motion dose of roll motions (time integrated roll acceleration with leakage). On the track side, results show that the amount of cant that minimises discomfort is dependent not only on vehicle speed and curve radius, but also on vehicle characteristics (such as tilt compensation ratio) and the lengths of the transition curves. The transition lengths that minimise discomfort are dependent on the variables mentioned above and on the angle between the connecting straight lines (when boundaries in available terrain corridors are taken into account). If cant is not optimised for the tilting trains, an alternative solution is to use a variable tilt compensation ratio (which may be individual for each curve). In order to enable the train to predeict optimal tilt on the next curve, track geometry data should be stored in onboard computers. Future research will be focused on these aspects. (A)
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