Use of numerical optimization to determine the effect of the roll stiffness distribution on race car performance

Abstract

The use of active systems for controlling suspensions has been used before in Formula One and other open wheel racing series but at present this form of active control is not allowed by Formula One regulations. The roll stiffness distribution is a key element of suspension design and it has an influence on the dynamic weight transfer of the vehicle. In this paper, the roll stiffness distribution has been optimized during a calculation process to simulate and quantify the possible benefits of controlling the distribution of roll stiffness between the front and rear axles of an open wheel race car. The roll axis concept has been used to provide the roll component to the lateral load transfer evaluation. The benefits shown by the optimization of the roll stiffness distribution have created a mean handling performance improvement over the base vehicle of over 10 per cent, which on the lap of the Barcelona Grand Prix circuit yielded a lap time improvement of 2.71 s, using a quasi-steady-state calculation method. Additionally, it has been shown how this improvement has been realized in terms of the change in vehicle dynamics. This research also shows that circuit dependent analysis is possible to exploit the value of the static setting of the roll stiffness distribution. Further work and validation are required to explore this avenue of vehicle set-up optimization, but it does appear that the optimized calculation approach offers a way of helping to make an objective choice of a static roll stiffness distribution setting for particular circuits.