Discrete-Valued Predictive Yaw Stability Control for Road Vehicles Using Differential Braking

Yaw stability control (YSC) using differential braking usually adopts a hierarchical control scheme by cascading yaw rate control, control allocation, and pressure control, leading to a complicated control structure and low dynamic performance. Regarding this issue, this article proposes a cascade-free discrete-valued predictive YSC (DV-P-YSC) scheme. Firstly, from a discrete ON/OFF perspective, the finite control combinations of the inlet and outlet valves for YSC are defined. Then, the control-oriented discrete-valued yaw rate model is presented. Secondly, the DV-P-YSC method is proposed. Neural network observers are constructed to compensate for the lumped disturbances. Then, the two-step-ahead yaw rate and one-step-ahead pressure predictions are performed by applying all candidate control combinations to the discrete-valued yaw rate model. A predefined cost function evaluates these yaw rate predictions and their pressure costs. The optimal prediction and corresponding control combination can be determined. In this way, the overall YSC is converted to an optimization problem with a discrete-valued decision variable. Then, the fuzzy decision-making strategy is introduced to avoid the empirical procedure of weighting factor tuning. Finally, a hardware-in-the-loop test bench is built to implement the proposed DV-P-YSC scheme. The experimental results validate the effectiveness of the proposed DV-P-YSC scheme.