| 摘要 |
PURPOSE:To prevent a vehicle from colliding against a wall and prevent scooping from occurring at the time of rapid braking, by a method wherein a rear- wheel steering angle is set at a zero phase when a front-wheel steering angle is small, and is set to be in a reverse phase when the front-wheel steering angle is large. CONSTITUTION:Front wheels 1, 1 and rear wheels 2, 2 are mechanically separated from each other, an output 4a from a front-wheel steering angle sensor 4 detecting a steering angle thetaH of a steering wheel 3 is inputted into a controller 10 for a rear-wheel steering gear, and the rear wheels 2, 2 are steered by the input signal. The magnitude of the rear-wheel steering angle thetaR relative to the front-wheel steering angle thetaF is enlarged as the vehicle velocity is increased, thereby improving response of the rear wheels to steering of the front wheels, and a steering ratio is reduced as the vehicle velocity is reduced, thereby facilitating turning of direction. In an extremely low velocity range (c), when the front-wheel steering angle thetaF is larger than a predetermined value, it is recognized that the direction of the vehicle is required to be largely changed, and the rear wheels are steered into the reverse phase to facilitate turning of the direction. |
