| 摘要 |
PURPOSE:To prevent a rear wheel steering angle from being abruptly changed accompanied with a change in car speed by deciding a rear wheel steering angle ratio to a front wheel steering angle based on a car speed substituted by a limit speed within a preset range when a change in car speed is out of the preset range. CONSTITUTION:A front wheel 1 is steered by a handle 2 by way of a front power steering device 3, furthermore, a rear wheel 4 is steered by a servo motor 5 by way of a rear power steering device 6, moreover, the servo motor 5 is controlled simultaneously by a motor drive device 7. And a control unit 11 computes a rear wheel steering angle ratio to a front wheel steering angle corresponding to vehicle speed based on signals form various sensors 12 and 13 for inputting a signal to the motor drive device 7. In this case, if a change in a vehicle speed is out of a preset range, the rear wheel steering angle ratio to the front wheel steering angle is decided based on a vehicle speed substituted by a limit vehicle speed within a preset range. Owing to this constitution, an abrupt change in a rear wheel steering angle accompanied with an abrupt change in vehicle speed is prevented. |
