A sensitivity based approach for racing cars design and set-up

The design and set-up process of a race car is a very complex procedure, its goal being the achievement of a vehicle with very high performances. Indeed, a huge number of factors have to be taken into account during the process. Many tools are however available for supporting the designer, ranging from CAD/CAE/CAM tools to complex KBD systems for the management of the entire decisional process. On the contrary, the task of checking the effects of set-up modifications with respect to performances is usually made, still nowadays, by road tests. Technicians and designers use their own experience and intuition to interpret tests results and to infer how to modify the car set-up to achieve the desired performances. This paper is aimed at proposing a design and set-up approach for racing cars based on the sensitivity analysis of a car model, performed while the vehicle is following a closed trajectory. Some manoeuvrability measures, such as the under-steer coefficient, have been taken as output variables of the considered system. To this purpose, a software tool has been developed allowing the monitoring of the variations of a chosen parameters set along the trajectory, on the basis of the sensitivity analysis. The proposed approach has been found effective in supporting the designer, providing information about how much car dynamic performances could be improved. Telemetry data have been used to verify results. The described approach could be effective applied also in the layout definition design phase.