Stability-Enhanced Traction and Yaw Control using Electronic Limited Slip Differential

Typical traction control systems based on brake intervention have the disadvantage of dissipating an amount of energy roughly equal to that spent in biasing the high-friction wheel. Fully locked differentials achieve the best possible longitudinal traction but, in situations such as slippery or split-friction (split-μ) surfaces, the lateral dynamics of the vehicle can be degraded and deviate from the driver's intended direction. This paper presents an active stability control strategy using electronic limited slip differentials to enhance the vehicle lateral dynamics while preserving longitudinal motion. The proposed control system includes stability enhancement of the traction control and yaw stability control. The stability-enhanced traction control is evaluated under the condition of straight-line full-throttle launching on a split-μ ice/snow surface. The experimental data show a significant stability improvement in a traction mode. The test maneuvers for high-speed yaw stability control include a slalom maneuver and an open-loop sine-steer maneuver on a low-friction (packed-snow) surface. These maneuvers were performed to evaluate yaw-damping performance.