Fault-Tolerant Architecture of Yaw Moment Management with Steer-by-Wire, Active Braking and Driving-Torque Distribution Integrated Control 2008-01-0110

A Steer-by-wire (SBW) system, which has no mechanical linkage, is expected to support the driver even in critical situations so as to improve collision safety and cockpit design flexibility. We have shown the effectiveness of driver assistance using an active steering control integrated with active braking control.[1] This is a case of normal driving without any vital component failures. The SBW system failure, however, can lead to an unsafe driving situation. A highly redundant design reduces the SBW failures but complicates its design and increases cost, volume and weight. This paper proposes a new fault-tolerant architecture to cope with the SBW failure. This is based on an integrated control by SBW, active braking, and driving torque distribution. A feasibility study is made using a driving simulator experiment during front obstacle avoidance under failed SBW. The proposed integrated control alleviates requirements for excessive redundancy of SBW components and thus facilitates wider use of SBW systems in a near future.