Optimal ride height and pitch control for championship race cars

Abstract Car performance in championship auto racing is strongly influenced by aerodynamics, particularly ground effects aerodynamics. Vehicles employing this technology require careful control of ride height and unsprung mass pitch in order to be stable, perform properly and achieve maximum success on the racetrack. In the past, attempts for controlling these vehicle variables centred around employment of very stiff “suspension systems” so as to prevent aerodynamic load buildup, which occurs at high race velocities, from causing excessive suspension travel. Control of these variables, however, may require use of an active suspension system, coupled with a controller which can adjust the suspension system in such a way as to mask road surface disturbance and aerodynamic noise. In the present work, a controller is developed for such a vehicle/suspension combination using linear quadratic stochastic regulator theory. Vehicle road inputs are modelled as Gaussian white noise, and are nearly completely rejected by the controller. In addition, representative aerodynamic inputs are also well controlled so that vehicle outputs of unsprung mass pitch angle and centre of gravity height are held constant.