Patent ID: 8010254

Claim:
A vehicle steering controller for a vehicle including a steering wheel to be manipulated by a driver and a turning mechanism mechanically separated from the steering wheel and including a rack shaft responsive to rotation of a pinion coupled to a pinion shaft, the turning mechanism operable to perform steering driving of at least one steered wheel corresponding to a steering angle of the steering wheel, the controller comprising: a tire lateral force detecting part configured to detect a tire lateral force acting on the at least one steered wheel and to output a tire lateral force value corresponding thereto; a friction-estimating part configured to estimate a steering system friction value, the steering system friction value including a resistance force of at least the rack shaft and the pinion; and a steering reactive force generating part configured to generate a steering reactive force for application to the steering wheel, the steering reactive force generating part including a first force generating part configured to generate a first steering reactive force component based on the tire lateral force value, a second force generating part configured to generate a second steering reactive force component based on the steering system friction value and a gain computing part configured to compute a gain value for each of the first steering reactive force component and the second steering reactive force component; and wherein the magnitude of the steering reactive force is a sum of the first steering reactive force component and the second steering reactive force component as adjusted by respective gain values.