Patent ID: 6842683
Filing Date: 2005-01-11
Classification: B60T

Abstract:
1. The method of controlling traveling stability of a vehicle, method comprising: setting a driver's desired yaw rates on various road surface conditions using a steering wheel angle and a reference speed of the vehicle while turning; judging a road surface condition on which the vehicle is traveling, by comparing lateral acceleration of the vehicle, which is estimated using the reference vehicle speed and a preset yaw rate on a preset reference road surface condition, with actual lateral acceleration measured by a lateral acceleration sensor; determining one of the driver's desired yaw rates corresponding to the judged road surface condition as a reference yaw rate, and determining whether the vehicle is understeered or oversteered by comparing the determined reference yaw rate with an actual yaw rate measured by a yaw rate sensor; controlling braking force and driving force according to the determination result; wherein the reference vehicle speed is calculated to set the yaw rates, and if the vehicle is a four-wheel drive car, the reference vehicle speed is calculated using the following Equation by varying weighting factors according to reliability of a value detected by a vertical acceleration sensor and a wheel speed so as to calculate the reference vehicle speed in consideration of a perturbation factor due to an error of the vertical acceleration sensor and the gravity acceleration in traveling on a banked road: where Vref is a reference vehicle speed, α is a weighting factor of the vertical acceleration, a x0 is a perturbation factor of the vertical acceleration, a x is a vehicle's vertical acceleration value, Δt is an integration time, c 1 is a weighting factor of a previous reference vehicle speed, and V wheel is a wheel speed.