Patent ID: 7721841

Claim:
A vehicular steering control apparatus comprising: a steering transfer system that transfers rotation of a steering wheel to a steered wheel turning mechanism that turns a steered wheel; a universal joint provided in an intermediate portion of the steering transfer system; a steering transfer ratio variable device which is provided in the intermediate portion of the steering transfer system and which changes a steering transfer ratio from the steering wheel to the steered wheel by changing a relative rotation angle of a steered wheel turning mechanism-side steering shaft to a steering wheel-side steering shaft; a power steering device that generates a steering assist torque; and a control device which computes a steering torque fluctuation-reducing steering assist torque control amount that is used to reduce fluctuation in steering torque transferred to the steering wheel based on a rotation angle of the steering wheel and the relative rotation angle, and which controls the power steering device based on the steering torque fluctuation-reducing steering assist torque control amount, wherein the steered wheel turning mechanism includes a rack-and-pinion steering device having a pinion shaft that is coupled to the steered wheel turning mechanism-side steering shaft by the universal joint, and the control device computes a ratio of an angular speed of the pinion shaft to an angular speed of the steering wheel based on the rotation angle of the steering wheel and the relative rotation angle, detects a steering torque of the pinion shaft, and computes the steering torque fluctuation-reducing steering assist torque control amount based on the ratio of the angular speed and the steering torque of the pinion shaft.