• A unified fault-tolerant control framework for vehicles was presented, utilizing rear-wheel steering (RWS), torque vectoring (TV), and their combination to address two types of complete Steer-by-Wire (SbW) failures. • Standard steering scenarios were applied in both simulations and real-vehicle experiments to quantitatively compare and evaluate the fault-tolerant control performance for each failure type and control strategy. • Based on the evaluation results, the maximum cornering performance and lateral dynamic characteristics for each failure type and control strategy were examined, and the findings were presented. This paper quantitatively compares and evaluates fault-tolerant control strategies to ensure vehicle-level safety under complete steer-by-wire (SbW) fault conditions. Previous studies were often limited to specific failure types or lacked systematic strategy comparisons, making it difficult to clearly identify their applicability and limitations. In this study, a unified fault-tolerant control framework addressing two types of complete SbW failures-fixed steering angle (FSA) and loss of steering torque (LST)–was developed. Within this framework, various strategies including rear-wheel steering (RWS), torque vectoring (TV), and their combinations were implemented, and performance was analyzed using standard evaluation scenarios: slow-ramp, sine-sweep, step, and 1-period sine steer. Simulation results indicate that under FSA failure, RWS-based strategies are relatively effective, with all strategies achieving near-nominal vehicle performance at high speeds. In contrast, LST failure leads to significant performance degradation due to unintended front-wheel steering, making nominal-level cornering unattainable. RWS-only control exhibits severe limitations, while partial compensation is achieved when combined with TV, demonstrating the benefit of multi-actuator coordination under fault conditions. These findings were further validated through real-vehicle tests, confirming the practical applicability of the proposed SbW fault-tolerant controller. By systematically comparing multiple strategies across both FSA and LST failure types under complete SbW conditions, the study provides fundamental insights for designing fault-tolerant controllers that account for failure-specific characteristics, establishing a foundation for future real-vehicle implementation and application research.
Ha et al. (Sat,) studied this question.