On the Traction Control of Single-Track Vehicles in Different Trim Conditions

This paper investigates the effects of a traction control system on the motorcycle's dynamics when both straight line or cornering conditions are considered. A nonlinear sliding mode controller has been chosen. When the rear wheel traction is lost after a rapid acceleration, the controller reduces the power supplied by the engine allowing the rear wheel to regain grip and stability. This situation has been simulated with the motorcycle running in vertical position and in leaning condition. The latter allows to investigate the behaviour of the traction control when the motorcycle's dynamic is more affected by the roll angle. The results show that the controller is able in both the cases to reduce the longitudinal slip of the rear wheel. Moreover, in leaning situation, the controller acting indirectly on the lateral dynamic reduces the oversteer, a phenomenon that can lead to the lowside fall. The simulations have been carried out by means of the motorcycle analytical model proposed by the authors in prior works. This mathematical platform is able to examine with sufficient detail the behavior of a two-wheeled vehicle in the most significant situations.