| 摘要 |
PURPOSE:To improve driving stability at the time of hauling a trailer in the captioned method in which rear-wheel steering angle is proportionally controlled to a front-wheel steering angle according to a rear-wheel steering coefficient by carrying out rear-wheel steering angle control according to a rear-wheel steering coefficient which is obtained according to a defined formula at the time of hauling a trailer. CONSTITUTION:In a four-wheel steering mechanism, steering angle sensors 4, 13 for detecting the steering angles deltaf, deltar of front wheels 3 and rear wheels 12 respectively, a vehicle speed sensor 5 for detecting a vehicle speed V, and a trailer traction sensor 7 are provided and their output signals are inputted into a control unit 6. The rear-wheel steering angle deltar is obtained a formula, deltar=Kdeltaf (K=rear wheel steering coefficient) to feedback control a rear-wheel steering actuator 8. In this case, at the time of hauling a trailed, a trailer- hauling-time steering coefficient kt is obtained from a formula, kt =1-{(1+ AtV<2>)/(1+AV<2>)}.(1-k) where, A, At=a stability factor at the hauling time and no-hauling time of a trailer, and rear-wheel steering angle control is performed according to this steering coefficient kt. |
