Vehicle mathematical model reduction considering the brake system dynamics

The present work shows a complete model for longitudinal movement of an automobile, starting with the reference coordinate systems; an inertial system, a system considering the vehicle as a rigid body and different coordinate systems for considering the center of mass of the tire and the contact element. Then the dynamics for subsystems involved in the braking process are described. The interest of the model is around the maximum value of the contact force, which physically means that the wheel is closed to a block situation. After this we obtained the characteristic values for every subsystem, and the model is evaluated for a metropolitan transport bus, Finally, considering the constant time for changes on the angular velocity as characteristic time we apply the fractional analysis to obtain a reduced order model of a vehicle, for the simulation the parameters of a bus were considered and the result the dynamics with enough accuracy for the conditions considered.