The Two-Mode Control for Steer-by-Wire System

Steer-by- Wire(SBW) system becomes a research focus for the improvement of vehicle performance by eliminating the mechanical linkage between steering wheel and steer-actuating mechanism. When SBW system is in power-off condition, the steer-actuating mechanism keeps a certain angle and remains immobilized while the steering wheel can still rotate because of the absence of the mechanical linkage. The steering wheel can rotate to a certain angle and will be locked by the steering column lock. This paper deals with the problem of asynchronization between steering wheel and steer-actuating mechanism at the start of system power-on condition by proposing the Two-Mode Control strategy for SBW system, which divides the control strategy into angle-synchronization mode control and steering mode control. The system enters the angle-synchronization mode at the start of power-on and then switches to the steering mode to execute the steering function. To verify the control strategy, a Simulink&CarSim co-simulation is carried out and the result of the Two-Mode Control shows that the asynchronization problem can be solved by the control strategy.