| 摘要 |
PURPOSE:To make highly accurate four-wheel steerage controllable, by altering a steering ratio characteristic on the basis of time mean value of the absolute value of a handwheel steering angle, while setting each desired steering ratio of both front and rear wheels on the basis of this steering ratio characteristic, and controlling a rear-wheel steering gear in accordance with the desired steering ratio. CONSTITUTION:In this steering gear, there is provided with a steering ratio setting means 104 which has the preset plural steering ration characteristics, and sets each desired steering ratio of both front and rear wheels on the basis of one of these steering ratio characteristics, and an actuator 51 is driven on the basis of the output, whereby each steering ratio of these front and rear wheels is controlled so as to become the desired steering ratio. And, in this case, a handwheel steering angle of a vehicle is detected by a steering angle detecting means 103, and time mean value of the absolute value of the detected handwheel steering angle is operated by an operational means 105. And, an output signal of this operational means 105 is inputted into a steering ratio characteristic altering means 106, and the steering ratio characteristic for setting the desired steering ratio is altered according to the time mean value of the absolute value of the handwheel steering angle at the steering ratio setting means 104. |
