Abstract
Monorail trains are widely used in cities and airports that have flat surface for relatively short distance transportation of limited number of passengers. In order to extend the use of monorail to hilly terrains up to 15 degree grade, a magnetic belt driving system that provides sufficient traction forces is proposed. The belt driving system where strong magnets are embedded inside each articulated element of the belt is used to supplement the main driving wheels with rubber tires when climbing up or down steep hill. To design the driving system, considerations are first given to determine stiffness of various suspension springs that dictate vertical, lateral, pitch and yaw motion frequencies of car body and bogie, which should be within some specific range between 1-2 Hz. To assess the hill climbing ability, stability on curving, and proper functioning of side and vertical constraint systems, a multibody model that takes into account of every component associated with suspensions and driving systems are set up. Through hill climbing simulation, maximum grade angle, requirements on the magnitude of magnetic forces, stopping distance, interaction between main rubber wheel driving system and magnetic belt driver when transiting form flat rail to inclined rail are investigated. Also by studying the curving behavior, maximum curving speed without rollover, functioning of lateral motion constraint system, geometry of guiding rails are studied. The validity of the multibody model for monorail design is demonstrated by 1/5 scale model which showed good correlations.
Keywords: monorail, magnetic belt, bogie, multibody model, curving stability