| 摘要 |
PURPOSE:To prevent the feeling of physical disorder from being generated in steering by operating at all times during travel at the time of contact that is due to reverse phase steering, being prevented, by finding a target rear wheel steering angle on the basis of a specific expression, in the rear wheel steering method of a front and rear wheel steering vehicle in which an actual rear wheel steering angle is controlled so as to be converged to the target rear wheel steering angle. CONSTITUTION:In the rear wheel steering method of a front and rear wheel steering vehicle, a controller 30 receives output signals from various sensors such as a front wheel steering angle sensor 31 to detect the steering angle of a steering shaft 12; vehicle wheel speed sensors 32; and a rear wheel steering angle sensor 33 to detect the steering angles of rear wheels RL, RR, and an actual rear wheel steering angle is controlled so as to be converged to a target rear wheel steering angle deltar obtained according to the detection values of a vehicle speed and the steering angles of front wheels FL, FR, and the target rear wheel steering angle deltar is sought on the basis of an expression I. In the expression I, deltaf denotes a front wheel steering angle; K denotes the steering angle ratio of front and rear wheels responding to a vehicle speed; (x) denotes a travel distance; Lr denotes a distance equivalent to one from a rear axle to the rear end of a vehicle; and (tau) denotes a time constant of a primary delay. |
