Patent ID: 7526372

Claim:
A steer-by wire control system comprising: a steering portion that is operated by a driver; steered wheels that are mechanically disconnected from the steering portion; a steered portion actuator to operate the steered wheels; a steering reaction force actuator to apply a steering reaction force to the steering portion; a backup apparatus that can connect mechanically the steering portion and the steered wheels; a power voltage supplier to supply electrical power to the steered portion actuator; and a controller that is applied to control the steered portion actuator, the steering reaction force actuator, and the backup apparatus; wherein the controller is configured to control the steered portion actuator to set a steered angle corresponding to a steering condition of the steering portion, the controller is configured to control the steering reaction force actuator to add a steering reaction force corresponding to a steered condition, the controller is configured to connect mechanically the steering portion and the steered wheels by the backup apparatus to perform steering assistance control when a power supply capacity of the power voltage supplier is reduced by a first threshold value or greater during steer-by wire control, the steer-by-wire control occurring when the steered wheels are mechanically disconnected from the steering portion, and the controller is further configured to set a second threshold value for disconnecting the backup apparatus to mechanically separate the steering portion and the steered wheels, wherein the first threshold value is equal to the second threshold value or is greater than the second threshold value.