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As a significant active safety technology towards fully autonomous driving, driver-automation co-piloting provides a new thinking for enhancing vehicle active safety and relieving driver's workload. However, the preview pattern divergence between driver and steering assistance system (SAS) may give rise to serious steering conflicts, which reduces driver's faith in SAS, cause him/her to turn off it, and even result in fatal traffic accidents. Focusing on mimicking the driver's steering behaviour, this paper proposes a human-like steering assistance scheme by adaptively varying the preview time and assistance gain of the SAS controller. Driver's preview behaviour of the road curvature is numerically identified using simulator tests along a multi-curves road, based on which a nominal preview-scheduled driver model is established. Based on the nominal driver model, a co-piloting system featuring human-like preview behaviour and a time-varying assistance penalty is proposed to formulate the steering torque-overlay dynamics of both agents in path-tracking. Next, a linear parameter varying (LPV)/H∞ controller satisfying pole placement is integrated to ensure the robustness and stability within the entire parameter space. This enables the steering assistance scheme to have a scheduled preview pattern like a human driver. Results of driving simulator experiment indicate that the proposed steering assistance scheme is able to mitigate driver-SAS conflicts and improve driver's path-tracking performance. [ABSTRACT FROM AUTHOR]

It was reported that Steer-By-Wire (SBW) system, which eliminates driver interference, could introduce the active front steering control easier than that with a conventional steering system. But there have been few reports on studies about reactive torque control strategy for the steering wheel. This research on reactive torque control strategy was carried out in order to improve the driver usability and maneouvrability of SBW system. It was found that the relation between what drivers feel by reactive torque when turning the steering wheel and what they feel from vehicle behaviour could be improved by means of applying newly developed reactive torque that incorporates vehicle dynamics by means of applying newly developed reactive torque reactive that incorporates vehicle dynamics parameter. [ABSTRACT FROM AUTHOR]

Abstract: Steer-by-wire (SBW) systems, which have no mechanical linkage between the steering wheel and front wheels, are expected to improve vehicle safety through better steering capability. SBW system failures, however, can cause hazardous driving situations. This paper introduces fault-tolerant architecture based on diversified steering mechanisms consisting of SBW backed up with steering by braking and acceleration during SBW failures. These backup steering functions are chosen according to driver''s intention of deceleration and acceleration. A loss of SBW function during front-obstacle avoidance on a straight highway is investigated by driving simulator experiments. The results show that the driver can maneuver the vehicle by the steering wheel during the SBW failures. Both cost and volume increase by excessive redundancy within SBW is avoided by the diversified design, thus facilitating SBW application on new-generation vehicles. [Copyright &y& Elsevier]