Lateral dynamics simulation of a three-wheeled tilting vehicle

A novel tilting three-wheeled vehicle was developed at the University of Bath as part of a project funded by the European Union. The space and weight savings provided by this type of vehicle could be a solution to the pollution and congestion problems seen in urban environments. The direct tilt control method originally implemented on the prototype was shown to perform well in the steady state, but rapid transients were shown to lead potentially to rollover instability. To investigate this phenomenon and to design an improved controller, a multi-body model was combined with a lateral dynamics single-track model to predict both the steady-state behaviour and the transient behaviour. With this model, it was possible to obtain an accurate representation of the kinematic and dynamic roll motions of the vehicle and the resultant weight transfer across the rear axle, together with the lateral dynamics of the vehicle. The simple lateral dynamics model provided an easily understood physical representation of the system which can often be hidden in a complex multi-body model. This paper presents the development of the model and its validation against data from static and dynamic tests.