A Stability and Tansparency Analysis of Steer-by-Wire System Based on the Bilateral Control and Dual-Port Network Theory

Compared with mechanical steering system, hydraulic steering system and electric power assisted system, Steer By Wire (SBW) system has the advantage of variable steering ratio, easy assembling and enhancement of active safety, etc.. Due to only electric link but no mechanical link between steering wheel and front wheel, the force between front wheel and steering wheel, which is of great importance to the assurance of road feel, cannot transfer to the driver. Combination with bilateral control theory of master-slave robot and dual-port network theory, a model of SBW system was established, considered the transfer delay of network. And the stability condition and transparency of SBW system also was given. Then, under the condition of stability, a control method to improve its transparency was put forward. Finally, based on the simulation results of front wheel's angle tracking and steering wheel's force feed back, the effects of several parameters, including transfer time, on the performance of system tracking, stability and transparency have been investigated.