Patent ID: 7392878

Claim:
A vehicle steering control system comprising: a steering angle ratio varying mechanism configured and arranged to vary a steering angle ratio of a manually operated steering mechanism; a variable power assisted steering mechanism configured and arranged to output an auxiliary steering force to the manually operated steering mechanism that supplements a driver steering force for turning steerable road wheels; a steering angle detection device configured and arranged to detect a steering angle of the manually operated steering mechanism; and a steering angle ratio controller configured and arranged to control the steering angle ratio varying mechanism to increase the steering angle ratio in a center steering angle range in a vicinity of a center steering angle position, and to reduce the steering angle ratio in a steering angle range in a vicinity of a maximum steering limit position, regardless of a steering angular speed of the manually operated steering mechanism, the steering angle ratio controller being configured to set a target steering angle ratio and control the steering angle ratio varying mechanism to obtain the target steering angle ratio, and the steering angle ratio controller being further configured to set the target steering angle ratio to vary an additional turning angular speed, which is an additional amount of a turning angular speed produced by the steering angle ratio varying mechanism, such that the additional turning angular speed increases in the steering range in the vicinity of the center steering angle position, and decreases in the steering range in the vicinity of the maximum steering limit position.