Research on yaw rate feedback control strategy of four-wheel steer-by-wire system

To improve the defects of traditional Four-Wheel-Steering system yaw rate feedback control strategy of Four-Wheel-Steer-by-Wire system was researched. Yaw rate feedback to rear wheels reduces steady sideslip angle to a very small value and decouples motions of yaw and sideslip; yaw rate feedback to front wheels can prescribe time constant of yaw, increase steering gain and improve responses of yaw rate. Simulation results of step response and frequency response show that presented four-wheel yaw rate feedback control strategy improves under steer tendency of traditional Four-Wheel-Steering, shortens reaction time, enhances the ability of driver to control vehicle accurately and so enhances handling stability.