VTI rapport 614A www.vti.se/publications Published 2008 Motion sickness in tilting trains Description and analysis of the present knowledge Literature study Rickard Persson Publisher: Publication: VTI rapport 614A Published: Project code: Dnr: 2008 40594 2004/0461-26 SE-581 95 Linköping Sweden Project: Tilting trains Author: Sponsor: Rickard Persson Swedish Rail Administration (Banverket) and Swedish Governmental Agency for Innovation Systems (Vinnova) Title: Motion sickness in tilting trains. Description and analysis of the present knowledge. A literature study Abstract (background, aim, method, result) max 200 words: Carbody tilting is today a mature and inexpensive technology allowing higher speeds in curves and thus reduced travel time. The technology is accepted by most train operators, but motion sickness is an issue still holding back the full potential of tilting trains. Evidence of motion sickness has been reported in air, in space, at sea, on cars, on trains, at fairground rides etc. There are more reports of motion sickness in tilting trains than in non-tilted trains, and the share of passengers getting motion sick is also higher in tilting trains. Motion sickness resulting from provocative experiments in laboratories is one very important key in finding the cause of motion sickness as provocative motions can be isolated in laboratories but not in real environments. Laboratory tests have proven that translations in all directions can cause motion sickness. Rotations seam to have less correlation with motion sickness than translations. However, all the laboratory tests causing motion sickness have been performed at amplitudes higher than amplitudes measured in tilting trains. Combinations of motions, in particular translations combined with rotations, may be the cause of motion sickness in tilting trains as combinations of motions are recognized as effective in creating motion sickness. The report has two main parts. The first part, chapters 2 and 3, covers the knowledge found in the literature and the experiences from tests performed in laboratories. Also reported and discussed are the issues where motion sickness has been found to appear, the character of the motions involved, different hypotheses for the causation of motion sickness as well as its time dependence. The second part, chapters 4 and 5, reports on specific motion quantities for tilting trains and their relations to motions known to cause motion sickness in laboratories. This part ends up with conclusions based on the literature and the analyses made. Keywords: Train, tilting trains, motion sickness, habituation, motion quantities ISSN: Language: No. of pages: 0347-6030 English 55 + 1 Appendix Utgivare: Publikation: VTI rapport 614A Utgivningsår: Projektnummer: Dnr: 2008 40594 2004/0461-26 581 95 Linköping Projektnamn: Korglutning Författare: Uppdragsgivare: Rickard Persson Banverket (Gröna Tåget) och Vinnova Titel: Åksjuka i korglutade tåg – beskrivning och analys av dagsläget Referat (bakgrund, syfte, metod, resultat) max 200 ord: Tåg med förmågan att luta korgarna inåt i kurvor är en prisvärd teknologi som möjliggör högre hastig- heter i kurvorna och därmed också kortare restider. Teknologin är accepterad av de flesta tågopera- törerna, men åksjuka begränsar idag utnyttjande av de korglutande tågens fulla potential. Förekomst av åksjuka har rapporterats i luften, i rymden, i bilar, i tåg, i nöjesparker etc. Det finns fler rapporter om åksjuka på korglutade tåg än på icke korglutade tåg och andelen åksjuka är också högre på korglutade tåg. Åksjuka som resultat av provocerande laboratorieexperiment är en mycket viktig nyckel till att finna orsaken till åksjuka eftersom provocerande rörelser kan renodlas i laboratorierna men inte i verkligheten. Laboratorieprov har visat att translationer i alla riktningar kan orsaka åksjuka. Rotation förefaller ha mindre koppling till åksjuka än translationer. Men, laboratorieprov som lett till åksjuka har alla utförts i högre amplituder än de som uppmätts på korglutade tåg. Kombinationer av rörelser, speciellt translationer kombinerat med rotationer, kan vara orsaken till åksjuka på korglutade tåg då kombinationer av rörelser är erkänt effektiva på att framkalla åksjuka. Rapporten har två huvuddelar. I den första, kapitlen 2 och 3, beskrivs kunskapsläget som det beskrivs i litteraturen samt erfarenheterna från laboratorieprov. Andra aspekter som rapporteras och diskuteras är var åksjuka uppträder, karaktären hos inblandade rörelser, olika hypoteser för uppkomsten av åksjuka samt dess tidsberoende. Den andra delen, kapitlen 4 och 5, beskriver och diskuterar storleksordningen hos rörelser som före- kommer på korglutade tåg i relation till rörelser som visat sig orsaka åksjuka i laboratoriemiljö. Denna del avslutas med slutsatser baserade på litteraturgenomgången och genomförda analyser. Nyckelord: Tåg, korglutning, åksjuka, tillvänjning, rörelsemängd ISSN: Språk: Antal sidor: 0347-6030 Engelska 55 + 1 bilaga Preface This study has been carried out at the Swedish National Road and Transport Research Institute (VTI), Linköping, in cooperation with the Royal Institute of Technology (KTH), Division of Rail Vehicles in Stockholm. This study is part of the research project “Gröna Tåget” (the Green Train). The financial support from Vinnova and the Swedish National Rail Administration, Banverket, is acknowledged. This report covers motion sickness with particular focus on tilting trains. Linköping March 2008 Rickard Persson VTI rapport 614A Cover: photos.com Quality review External peer review was performed by Joakim Dahlman and Torbjörn Ledin, Linköping University. Rickard Persson has made alterations to the final manuscript of the report. The research director of the project manager Lena Nilsson examined and approved the report for publication on March 17, 2008. Kvalitetsgranskning Extern peer review har genomförts av Joakim Dahlman och Torbjörn Ledin, Linköpings universitet. Rickard Persson har genomfört justeringar av slutligt rapportmanus. Projektledarens närmaste chef Lena Nilsson har därefter granskat och godkänt publikationen för publicering 2008-03-17. VTI rapport 614A Table of contents Terminology and definitions................................................................................ 5 Local reference system ...................................................................................... 5 Symbols and abbreviations ................................................................................ 6 Summary……..................................................................................................... 7 Sammanfattning ................................................................................................. 9 1 Introduction............................................................................................ 11 1.1 Background to the present study ........................................................... 11 1.2 Objective and approach of the present study......................................... 12 2 Evidence of motion sickness.................................................................. 13 2.1 Signs and symptoms ............................................................................. 13 2.2 Motion sickness questionnaires ............................................................. 14 2.3 Motion sickness reports ......................................................................... 16 2.4 Motion sickness in laboratories.............................................................. 25 2.5 Summary ............................................................................................... 33 3 Hypothesis of motion sickness............................................................... 35 3.1 Human receptors ................................................................................... 35 3.2 The conflict theory ................................................................................. 35 3.3 Competing theories................................................................................ 37 3.4 Time dependence of motion sickness.................................................... 37 4 Motions in trains..................................................................................... 42 4.1 Nominal motion quantities...................................................................... 42 4.2 Measured motion quantities................................................................... 43 4.3 Motion quantities – experienced motion sickness.................................. 46 5 Discussion and conclusion..................................................................... 48 5.1 Discussion ............................................................................................. 48 5.2 Conclusion ............................................................................................. 48 5.3 Suggestions for further research............................................................ 49 References……................................................................................................ 50 Appendix A FACT Motion sickness questionnaire VTI rapport 614A VTI rapport 614A Terminology and definitions Term Definition Horizontal Direction in plane to earth horizon Motion sickness Sickness caused by motion Nausea Sensation of unease and discomfort in the stomach Oculomotor Nerve in the mid brain connected to eye control muscles Otoliths Vestibular organs sensitive to linear acceleration Proprioceptive Information of the body posture from sensors