Driver-automation shared steering control for highly automated vehicles

A model predictive control (MPC)-based shared steering framework for intelligent vehicles is proposed in this paper. The road boundary and vehicle stability boundary are regarded as the safe envelope, and the tradeoff between the freedom of driver operation and safety assurance of intelligent vehicles is made within this safe envelope. Under this cooperative steering framework, the reliability of drivers is analyzed in dangerous situations and in the predictive time domain, and two improved schemes are proposed. Under the two improved schemes, the weight of the control objective can be adaptively changed according to the results of the threat assessment and predetermined strategy. At the same time, an evaluation index named control intervention rate and risk rate is proposed to evaluate the designed human-vehicle cooperation scheme. The simulation results show that the performance of the two improved schemes in ensuring the safety of intelligent vehicles has been improved.