Patent ID: 7295908

Claim:
A vehicle steering apparatus of a steer-by-wire system provided with a steering handle operated by a driver for steering a vehicle, a turning actuator for turning steered wheels and a turning control device that drive-controls the turning actuator according to the operation on the steering handle for turning the steered wheels, wherein the turning control device comprises: operation input value detecting means that detects an operation input value by a driver to the steering handle; motion state quantity calculating means that calculates an anticipated motion state quantity of the vehicle by using the detected operation input value, wherein the anticipated motion state quantity of the vehicle represents the vehicle motion state, that relates to a turn of the vehicle and can be sensed by a driver, and is in the predetermined relation of exponential function or in the predetermined relation of exponentiation function with the operation input value to the steering handle; turning angle calculating means that calculates a turning angle of the steered wheels necessary for the vehicle to turn with the anticipated motion state quantity calculated by the motion state quantity calculating means by using the calculated motion state quantity; motion state quantity detecting means that detects an actual motion state quantity representing an actual motion state of the vehicle; steering characteristic quantity calculating means that calculates a steering characteristic quantity relating to the vehicle actual turning state based upon the detected actual motion state quantity; turning angle correcting means that corrects the calculated turning angle by using the calculated steering characteristic quantity in order to generate the calculated anticipated motion state quantity; and turning control means that controls the turning actuator according to the corrected turning angle for turning the steered wheels into the corrected turning angle.