| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric power steering device capable of enhancing steering feeling without providing a torque sensor in order to determine a target assistant force by determining the target assistance force based on a steering angle changing accompanied by the operation of a steering wheel. SOLUTION: In the electric power steering device, the target assistance force is determined based on the operation of the steering wheel 30 of the vehicle, a motor 5 for steering assistance is driven according to the determined target assistance force to assist the steering. A steering angle changing accompanied by the operation of the steering wheel 30 and steering angular velocity and steering angular acceleration calculated from the steering angle are applied to an equation of motion to calculate required torque, and the target steering torque is calculated from the calculated required torque. Therefore, it is not required that the torque sensor is provided in order to determine the target assistance torque, and the steering feeling can be enhanced by constituting a steering shaft 3 by a hollow material or a solid material with high rigidity. COPYRIGHT: (C)2008,JPO&INPIT |
