| 摘要 |
PURPOSE:To eliminate any adverse effect due to something wrong with a yaw rate detecting means as well as to make sure of safety by prohibiting any control by a yaw rate when each steering angle variation in front wheels and a product of the yaw rate are all smaller than the specified value of less than zero, in a device which steers rear wheels on the basis of the yaw rate. CONSTITUTION:When a front-wheel steering angle being detected by a front- wheel steering angle sensor 35 is set to thetaF, a car speed being detected by a car speed sensor 31 to V, a yaw rate being detected by lateral G sensors 33, 34 to psi, and factors dependent upon a vehicle characteristic to KF and KR, respectively, each target steering angle TGthetaR of rear wheels is calculated on the basis of a numerical formula of TGthetaR=-KF.thetaF+KR.V.psi. Then, a servomotor 20 is controlled on the basis of this target steering angle TGthetaR, steering the rear wheels. In this case, when each steering angle variation of front wheels and a product of the yaw rate are smaller than the specified value of less than zero, it is so judged that there is something wrong with these lateral G sensors 33, 34, whereby any steering control over the rear wheels based on the yaw rate is prohibited afterward. |
