To evaluate the handling behaviour of the vehicle in the normal-driving and limit manoeuvres, under a variety of road conditions (dry, wet, μ-split, etc.), a dynamic model that can be effectively integrated with chassis control systems' algorithms like anti-skid devices, vehicle dynamic control, active suspensions, servo-assisted steering and braking, would be very useful.
A modular, flexible, 15 degrees of freedom (DOF) model of the vehicle dynamics, implemented in Simulink, is presented here. It can be used “stand-alone” for vehicle handling performance prediction; integrated with control system algorithms, for their synthesis and offline pre-calibration; in “Hardware-in-the-loop” configurations, for testing control and diagnosis algorithms functionality.
The model uses the Pacejka Magic Formulae for tyre modelisation and a Lagrangian approach for chassis, corners and powertrain dynamics. Suspensions' kinematics and compliance effects are reproduced through a functional approach, so that either experimental data can be imported directly from a full-vehicle test bench, or look-up tables can be derived from suspension requirements.
The model has been used for simulating several “open-loop” handling manoeuvres, including roll-over tests, with wind and road gradient influences. A good correlation with experimental data has been observed.