Abstract
Keywords - race car, dynamic, vehicle model, tire loads, tire angles.
Abstract - In this work a software tool, developed under Matlab/Simulink® environment with the aim of analysing the dynamical behaviour of a race car is presented. The work, developed in cooperation with Draco Junior racing team, was focused on the cars taking part in the Euro 3000 championship.
Limits imposed by the race regulations on the number and type of signals that can be acquired during a lap, leave unknown many dynamic quantities, which, on the contrary, could be very useful for optimal vehicle set-up. For the same reason, vehicle set up is in part remitted to the engineers and drivers experience. The on board data acquisition system, which is identical for all the teams, provides longitudinal and lateral acceleration, with respect to a non inertial reference system fixed on the vehicle, steering wheel angle, suspension deflections, vertical tire loads, angular velocity of the wheel rims, engine rpm, inserted gear and butterfly valve position.
The developed tool includes a track reconstruction procedure, based on three different recorded signals, which was optimised against experimental errors propagation. In addition, the tool is based on a accurately developed mathematical model, containing a precise description of the vehicle main subsystems, such as suspensions, steering, differential, aerodynamic appendixes and braking systems. Starting from recorded data, by solving a set of equations, which depend on vehicle motion conditions (i.e. traction or breaking manoeuvres), the tool is capable of giving all the loads components (i.e. vertical, lateral and longitudinal) at ground, the suspended mass roll angle and the cornering and camber angles of all the tires.
Finally, the developed software was endowed with a user friendly graphical interface, for both setting up vehicle parameters and performing data analysis and storage. The model and some results are presented and discussed with reference to three different Italian circuits, i.e. Monza, Misano Adriatico and Vallelunga.