J. Forstberg et al., INFLUENCE OF DIFFERENT CONDITIONS OF TILT COMPENSATION ON MOTION AND MOTION-RELATED DISCOMFORT IN HIGH-SPEED TRAINS, Vehicle System Dynamics, 29, 1998, pp. 729-734
Train speed may be increased by constructing new railways with improve
d curve geometry or by using tilting trains. The tilting system compen
sates the lateral acceleration felt by the passengers in curves by til
ting the car body, thus allowing trains to run 25-30 % faster on exist
ing curved tracks with maintained good ride comfort. Although motion s
ickness in tilting trains seems to be a small problem for most passeng
ers it can be a problem to those prone to nausea. To investigate the i
ncidence of motion related discomfort and how different tilt compensat
ion strategies influence the occurrence of such discomfort, a full-sca
le test ride was conducted on a curved track with a tilting train. Sev
enty healthy volunteers were employed, selected for high subjective se
nsitivity to nausea. Three conditions were tested using three differen
t cars under three days. The test ride lasted about 3 hours. Four time
s per test ride the subjects answered a questionnaire concerning veget
ative symptoms, fatigue, sleepiness and nausea. The test persons' over
all estimation of average ride comfort was good in all conditions, how
ever, some persons reported motion related discomfort due to motion si
ckness. A 55% degree of tilt compensation of the lateral acceleration
(in the track plane) instead of the normal 70%, reduced the number of
test persons reporting dizziness and nausea by about 30 - 50%. Discomf
ort correlates very poorly with a motion dose (time integrated) of ver
tical acceleration but instead correlates better with a motion dose of
roll angle acceleration.