| 摘要 |
PURPOSE:To enable rear wheel control operation corresponding to the travel state so as to improve travelling safety by steering rear wheels onto the opposite phase side in a case of the lateral force of front wheels being larger than that of the rear wheels and onto the same phase side in a case of the lateral force of the rear wheels being larger than that of the front wheels. CONSTITUTION:A front wheel steering angle thetaf is read from a steering angle sensor 43, and each wheel lateral force information YFR, YFL, YRR, YRL is read from a lateral force detecting device 50. The lateral forces acting upon left and right wheels are then compared wheel by wheel, and in case the difference in even one of them is over the specified value, the lateral force acting upon each wheel is combined to obtain integrated lateral force Y. According to this, a steering ratio (k) is determined from a steering ratio characteristic to compute a rear wheel steering angle theta for rear wheel steering control. The steering ratio characteristic to the lateral force functions in such a way as to steer the rear wheels in the opposite phase at the time of easy turning with low lateral force so as to improve turning-round performance and to steer the rear wheel in the same phase in the case of lateral force being large so as to improve turning safety. |
