Steer-by-Wire as a Mechatronic Implementation

Steer by wire (SBW) systems in which the mechanical link between the steering wheel and road wheels of an automobile are replaced by a control system consisting of sensors, actuators and controllers seem to offer great advantages such as enhanced system performance, simplified construction, design flexibility etc. However, for implementation in road vehicles, safety considerations and fault tolerance become major issues and have to be taken into account. In the paper, a SBW control system configuration which takes the safety aspects into account is presented. The proposed system comprises a redundant force-feedback steering wheel actuator to provide road feedback to the driver and a redundant front wheel actuator. Salient results are given based on simulations of the system or measurements conducted on a test rig.