Road Feel Modeling and Return Control Strategy for Steer-by-Wire Systems 2024-01-2316

The steer-by-wire (SBW) system, an integral component of the drive-by-wire chassis responsible for controlling the lateral motion of a vehicle, plays a pivotal role in enhancing vehicle safety. However, it poses a unique challenge concerning steering wheel return control, primarily due to its fundamental characteristic of severing the mechanical connection between the steering wheel and the turning wheel. This disconnect results in the inability to directly transmit the self-aligning torque to the steering wheel, giving rise to complications in ensuring a seamless return process. In order to realize precise control of steering wheel return, solving the problem of insufficient low-speed return and high-speed return overshoot of the steering wheel of the SBW system, this paper proposes a steering wheel active return control strategy for SBW system based on the backstepping control method. First, the dynamics model of the SBW system is established, thereby laying the foundation for further analysis. Next, an active return judgment logic based on steering wheel angle, driver torque and the change rate of driver torque to make informed decisions regarding return control is proposed. Then, the active return control algorithm based on the backstepping control method is designed and the stability analysis of this algorithm is provided to ensure its reliability in practice. At last, the effectiveness of the steering wheel active return control strategy is evaluated by simulations and hardware-in-the-loop test. The results show that the return control strategy can accurately judge the return time and have a relatively good return effect with the low-speed return deficiency and high-speed return overshoot of steering wheel be alleviated.