Hand-wheel steering signal estimation and diagnosis approaches for ground vehicles

This paper presents two methods for estimating the ground vehicle hand-wheel steering signals and for detecting the voltage-to-angle conversion and hand-wheel steering sensor faults. An enhanced input observer is used to estimate the actual hand-wheel steering angular signal and a sliding mode approach is utilized to improve the robustness of the method with respect to the parametric uncertainties associated with actual vehicle operations. The performance and effectiveness of the proposed hand-wheel steering angle estimator and diagnosis methods are shown by experimental results obtained on a ground vehicle equipped with a single incremental, low-cost, angular steering sensor.