Velocity-dependent robust control for improving vehicle lateral dynamics

In this paper, a yaw moment controller of which parameters are dependent on the vehicle forward velocity is designed for improving vehicle handling and stability. Robustness of the controller is enhanced with considering the parameter uncertainties arising from tyre cornering stiffness and the actuator saturation limitations resulting from some physical constraints and tyre–road conditions into the controller design process. The design of the controller is achieved by solving finite numbers of linear matrix inequalities (LMIs). Effectiveness of the designed controller is shown through numerical simulations performed on a nonlinear vehicle model. Improved performance on vehicle handling and stability can be observed from the sideslip angle and yaw rate responses under a J-turn manoeuvre with different vehicle forward velocities, road conditions, and actuator saturation limitations.