Abstract
The purpose of this study is to establish an evaluation method of ride comfort of high-speed passenger craft. For the conventional displacement-type ships, vertical acceleration was used to be analysed so as to estimate ride quality of vessels or the motion sickness incidence (MSI) which represents the percentage of a group who will vomit during the voyage. This is because the principal vertical motion of most ships is close to 0.2 Hz where motion sickness sensitivity is considered to be at a maximum. Various types of stabilizer have been designed to reduce the rolling motions of ships. However, it is pointed out that lateral acceleration cannot be negligible for evaluating ride comfort of especially high-speed catamaran. Effect of vertical motion might be rather small because oscillatory frequencies of vertical motion are somewhat higher. Sway motion of high-speed crafts therefore comes to be a research subject overseas too. The authors have conducted experiment on ride comfort of a high-speed craft. Ship motion and subjects' psychological and physiological responses were measured in a high-speed craft running across the Bay of Osaka. The present paper deals with analysis of ship motion and proposes an evaluation method introducing the concept of the “frequency weighting” defined in ISO 2631-1 (1997).
