A Simple Approach for Online Yaw Rate Response Adjustment in Steer-by-Wire Vehicles

To facilitate easier adjustment of yaw rate response characteristics and enhance yaw stability of steer-by-wire vehicles, an active front steering (AFS) control module consists of feedforward and feedback control module is proposed. By identifying the vehicle’s yaw rate response as the transfer function form deduced from two degree of freedom vehicle model, it becomes possible to design an appropriate feedforward controller to adjust the yaw rate response characteristic. Two parameters of designed feedforward controller can directly change the rise time and overshoot of yaw rate response, supporting online yaw rate response adjustment. Additionally, a proportional-integral controller is employed as feedback controller to improve the vehicle yaw stability. To ensure the safety of online parameters calibration, a limitation module is implemented. Simulation experiments and actual vehicle tests are conducted. The tests results validate the effectiveness of proposed AFS module.