Patent ID: 6922621

Claim:
A steering control system for a vehicle including a steering wheel shaft transmitted with an operation angle of a steering wheel, a vehicle wheel steering shaft mechanically disconnected from the steering wheel shaft, and an actuator for rotating the vehicle wheel steering shaft at a vehicle wheel steering angle depending on the operation angle of the steering wheel and a vehicle driving condition, the steering control system comprising: a steering wheel shaft angle detecting means for detecting a steering wheel shaft angle position; a vehicle wheel steering shaft angle detecting means for detecting a vehicle wheel steering shaft angle position; a vehicle condition detecting means for detecting the vehicle driving condition; and a drive controlling means for determining a target angle position of the vehicle wheel steering shaft based upon the steering wheel shaft angle position and the vehicle driving condition and for controlling the operation of the actuator so as to approximate the vehicle wheel steering shaft angle position to the target angle position, the drive controlling means comprising: a final angle position memorizing means for memorizing a final angle position representing the vehicle wheel steering shaft angle position at a time of termination of the vehicle driving operation, the final angle position memorizing means capable of maintaining the memory content even when the vehicle is stationary; an input, complete data memorizing means capable of switching the memory content between a first memory condition and a second memory condition, the first memory condition indicating completeness of writing of the final angle position in the final angle position memorizing means, and the second memory condition indicating failure in writing the final angle position therein, the input complete data memorizing means capable of maintaining the memory content even when the vehicle is stationary; an input complete data memory controlling means for setting the memory content memorized in the input complete data memorizing means at the first memory condition in response to the completeness of writing of the final angle position in the final angle position memorizing means; and an initial angle position set controlling means for allowing to employ the final angle position memorized in the final angle position memorizing means as an initial angle position of the vehicle wheel steering shaft when the memory content in the input complete data memorizing means is at the first memory condition at a time of restart of the vehicle driving operation after temporal termination of the vehicle driving operation and for prohibiting to employ the final angle position as the initial angle position when the memory content in the input complete data memorizing means is at the second memory condition at the time of restart of the vehicle driving operation after the temporal termination of the vehicle driving operation.