A feedback-feedforward steering controller designed for vehicle lane keeping in hard-braking manoeuvres on split-μ roads. Issue 5 (4th May 2022) - Yu, Liangyao
Abstract : Keeping a vehicle in its current lane without veering into adjacent lanes is important in hard-braking manoeuvres on split- μ roads. Whether the emergency braking is initiated by a human driver or by an AEBS, drivers have difficulty adjusting steering correctly to balance yaw moment generated by asymmetric tyre braking force. Some anti-lock braking systems reduce braking force to reduce the yaw moment, which will increase braking distance. To improve the stability in the abovementioned scenario, a feedback-feedforward steering controller is proposed in this paper. To describe the tyre force characteristics of combined slip and nonlinearity, a linear tyre model based on the total differential method is developed. The receding horizon linear quadratic regulator method is utilised to design the feedback steering input to drive state variables to zero in the finite domain. And fuzzy logic is developed to tune the weighting matrix. Furthermore, feedforward steering input is designed to suppress path tracking steady-state error. The performance of the proposed controller is illustrated by hard-braking manoeuvres experiments on normal split- μ and 'checkerboard' roads.