OPTIMAL CONTROL STRATEGIES FOR RACE CARS SUBJECTED TO DISCRETE TRACK IRREGULARITIES.
Modern race cars making use of aerodynamic effects to achieve better surface traction have typically been plagued by the problem of ride height instability caused primarily by road surface disturbances and the aerodynamic 'negative spring' phenomenon. In this paper a three-dimensional vehicle suspension model is formulated accounting for pitch, roll, and heave. An optimal controller is designed to minimize a standard quadratic performance functional with a target control time. The quadratic performance index in use is of the type integral **T//O (y prime Qy plus u prime Ru)dt, where y(t) and u(t) represent the system output and system control vector respectively; T is the target control time; and Q and R are positive semidefinite and positive definite matrices, respectively. The cause of perturbation is assumed to be a sudden irregularity in an otherwise smooth race track.