Stability Control for Brake-by-Wire Vehicles Under Cornering Braking Based on Dynamic Load Distribution and Improved Sliding Mode Control

During cornering braking, longitudinal braking and lateral tire forces share the limited tire–road adhesion capacity and induce dynamic load transfer among the four wheels, thereby intensifying the coupling between braking performance and lateral stability. Improper braking-force distribution may consequently cause premature tire-force saturation, excessive yaw response, and vehicle sideslip. To address this problem, this study proposes a coordinated cornering-braking stability control strategy for brake-by-wire vehicles. The total braking force is first determined according to the desired deceleration and initially distributed among the four wheels based on their estimated dynamic vertical loads. An improved sliding mode controller with adaptive yaw–sideslip weighting then generates an additional yaw moment, while a sequential quadratic programming algorithm redistributes the wheel braking forces, subject to the total braking-force, additional yaw-moment, and tire-friction-circle constraints. The proposed strategy was evaluated using CarSim/Simulink co-simulations under eight operating conditions involving different initial speeds, braking demands, and road-adhesion levels. Compared with the proportional distribution strategy, the optimized strategy reduced the yaw rate root-mean-square error by 76.2–98.6%, the maximum sideslip angle tracking error by 8.1–97.4%, and the maximum magnitude of the actual sideslip angle by 20.9–98.6%. The improvements were particularly pronounced under high-speed and high-braking-demand conditions. Although the stability-priority allocation moderately extended the braking duration in some cases, it effectively suppressed excessive yaw and sideslip responses, demonstrating its simulation-level effectiveness in improving the cornering-braking stability of brake-by-wire vehicles.