1,721,154 research outputs found
Metodo e dispositivo per la determinazione dell’angolo di rollio di un veicolo
No full textLa presente invenzione riguarda un metodo ed un dispositivo per la determinazione dell’angolo di rollio in un motociclo o di altro veicolo sprovvisto di sistema per il controllo attivo del rollio ed atto ad inclinarsi lateralmente rispetto al piano stradale quando percorre un tratto di strada in curva
A motorcycle tire model for dynamic simulations: Theoretical and experimental aspects
No full textThis paper describes a model for motorcycle tires based on a physical interpretation of experimental data. In this model the real shape of the tire carcass is accurately described and its deformability is taken into account. The actual position of the contact point, that is, the center of the contact patch, is calculated. The concept of instantaneous slip is defined by calculating the longitudinal slip and sideslip angles using the velocity of the actual contact point, which moves with respect to the rim. Tire forces and torques are applied on the actual contact point and calculated according to Pacejka's magic formula. The coupling of sliding properties with elastic ones and the use of the instantaneous slip concept make it possible to properly describe both steady state and transient behavior using the same relations, thus avoiding the use of any auxiliary equations
Gyroscopic stabilisers for powered two-wheeled vehicles
No full textThis paper illustrates the potential of a gyroscopic stabiliser for the stabilisation of single-track vehicles, at low and high speed as well as during braking. Alternative systems are considered, including single and twin counter-rotating gyroscopes, spinning and precessing with respect to different axes, either freely (passive stabilisers) or in a controlled way (active stabilisers). A suitable mathematical model has been developed and stability has been investigated both by eigenvalue calculation and time domain simulations. It has been found that the most effective configuration is one where the gyroscope(s) spin with respect to an axis parallel to the wheels' spin axis and swing with respect to the vehicle yaw axis. Passive systems may effectively stabilise both weave and wobble at medium and high speed, but cannot stabilise the vehicle at low and zero speed. On the contrary, actively controlled gyroscopes are capable of stabilising the vehicle in its whole range of operating speed, as well as during braking. The alteration of the original vehicle handling characteristics is negligible when active counter-rotating gyroscopes are used, and still acceptable if a single gyroscope is adopted instead
A combined model of tire and road surface for the dynamic analysis of motorcycles handling
No full text
A Motorcycle Multi-body Model for Real Time Simulation Based on the Natural Coordinates Approach
No full textThis paper presents an eleven degrees of freedom, non-linear, multi-body dynamics model of a motorcycle. Front and rear chassis, steering system, suspensions and tires are the main features of the model. An original tire model was developed, which takes into account the geometric shape of tires and the elastic deformation of tire carcasses. This model also describes the dynamic behavior of tires in a way similar to relaxation models. Equations of motion stem from the natural coordinates approach. First, each rigid body is described with a set of fully cartesian coordinates. Then, links between the bodies are obtained by means of algebraic equations. This makes it possible to obtain simple equations of motion, even though the coordinates are redundant. The model was implemented in a Fortran code, named FastBike. In order to test the code, both simulated and real slalom and lane change maneuvers were carried out. A very good agreement between the numerical simulations and experimental test was found. The comparison of FastBike's performance with those of some commercial software shows that first is much faster than others. In particular, real time simulations can be carried out using FastBike and it can be employed on a motorcycle simulator
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