Modeling and Control of a Motorbike

Abstract

The work developed in this thesis explains the construction of both kinematic and dynamic models for a motorcycle, and the design of a control strategy that can command the bike autonomously, under normal driving conditions. All results have been tested in several diverse conditions through a Matlab implementation, in order to validate the model and to obtain information about the motorcycle behavior. The kinematic model builds upon existing models, which do not include some of the aspects contained in this work yet. For instance, the features incorporated in the model are the front fork inclination, the movement of suspensions along with the damping system, the consequences of the pneumatic shapes when the motorbike leans, and the analysis of the kinematics of the double swingarm vehicles. A dynamics model was built through the Lagrangian method. Firstly, the motorcycle has been analyzed with the help of the free Lagrangian equations and secondly all external forces have been added. The results obtained suggest that the model is indeed valid. The control system considered is a simple PID. This choice is motivated by the fact that the structure and parameters of a PID can be easily identified with the actions used by a typical human rider. The comparison between the simulated results with those from a real motorbike in a racetrack validates the choice of this simple control strategy in this particular application.