Directional stability is an important parameter in high speed as well as in low speed maneuvering. A three - wheeled vehicle has a tendency to pull one side resulting in poor directional stability. This pulling requires continuous steering correction for improving directional stability. Driver needs to apply more force on handle bar to stabilize the vehicle. This causes the driver to experience shoulder pain and inferior maneuverability. A vehicle one side pull problem is directly related to safety and comfort. Also, during riding external disturbances from road generate lateral forces in tyre leading to sudden path deviation of vehicle. This path deviation deteriorates handling and it becomes difficult for the rider to control it to its original position. The aim of this work is to understand the influence of various parameters on three wheeled vehicle directional stability.
Different parameters such as front steering CG offset, uneven mass distribution, wheel camber, caster angle, trail, road camber, air drag and tyre conicity etc., contribute to one side pulling of the vehicle. The focus of the present work is on studying parameters like, caster angle, trail, and camber and their effects on directional stability of three - wheeled vehicle. A validated three wheeled vehicle multi body model in ADAMS is used for simulation to evaluate the degree of effects on the directional stability of three wheeled vehicle. The findings from this study have improved the understanding of the effect of caster angle, trail, and camber on directional stability during hands free steering condition. The design parameters are determined based on simulation for better directional stability. Simulation output is validated experimentally by free control test. The feasible solution for better directional stability among caster, trail and camber is arrived.