Evaluation of chassis control method through optimisation-based controllability region computation

This paper proposes a new systematic evaluation approach for vehicle maneuverability based on controllability region computations. In this approach, the controllability region, defined as the set of vehicle initial states that can be transferred to a stable equilibrium point in the state space by using allowable controls, is calculated. The size of the controllability region for an open-loop system can serve as a measure of the intrinsic performance of the control method, because if the vehicle state is displaced outside of the controllability region, no controller will be able to maintain vehicle stability. The problem of determining the controllability region boundary is formulated as an optimisation problem such that the controls maximising the norm of the initial state can be determined. Thereby, the performances of four-wheel steering control and direct yaw moment control are evaluated and compared by the proposed procedure.