Optimization-based non-linear yaw moment control law for stabilizing vehicle lateral dynamics

For a direct yaw moment control (DYC) system, using an external yaw moment that is as low as possible for stabilizing the vehicle-handling dynamics in the non-linear regimes can be considered as an important advantage. In this paper, to achieve this aim, an optimization-based side-slip tracking law is developed for DYC by the response prediction of a continuous non-linear vehicle dynamics model. A new desired model for the vehicle side-slip angle based on the linear vehicle model and tyre-road conditions is presented to be tracked by the controller. Two versions of the proposed non-linear control law are considered here and the performances of the two versions are compared. The derived control law has an analytical closed form in which online numerical computations in optimization are not required. The effectiveness of the designed controller is investigated by simulations of various manoeuvres using a developed, non-linear, full-vehicle dynamic model. The simulation results indicate that a satisfactory handling performance through a reduced external yaw moment can be achieved when the proposed optimal controller is applied.