| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an electric power steering device highly accurately performing a power assist control constantly, in the electric power steering device, in which a rotary motion of a steering wheel is converted into a linear motion of a steering rack shaft and a tie rod connected thereto to steer a steering wheel. <P>SOLUTION: The rack axial force F acting on the steering rack shaft 16 is estimated by calculation, based on a physical amount indicating a traveling state of a vehicle. A crossing angle θ of the rack shaft 16 and the tie rod 17R, which is projected onto the inside of a vertical plane in an advance direction of a vehicle body, is acquired. Based on the crossing angle θ, the estimated rack axial force F is corrected. Therefore, overestimation of the rack axial force is prevented when the vehicle is tilted to a right or left side to generate a suspension stroke during traveling of the vehicle. <P>COPYRIGHT: (C)2013,JPO&INPIT |
