| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric power steering device prevented in overheating of a steering assist motor and improved in steering feeling by accurately determining a steering angle end and accurately reducing the driving current for correction. SOLUTION: The electric power steering device determines a target assist force based on the steering torque applied to a vehicle steering member 30, and controls to increase/reduce the driving current of the steering assist motor 5 corresponding to the target assist force, and on the other hand, reduces the driving current for correction when the steering mechanism is positioned in a right and a left steering angle end positions. The electric power steering device determines existence of movement of a steering shaft on an output side thereof based on a change ratio of turning angle detected by a turning angle sensor 4b on an output side of the steering shaft, and reduces the driving current for correction in response to the determination. The steering angle end is accurately determined, and the driving current is accurately reduced for correction in the steering angle end to prevent overheating of the motor and waste of power. In the case except the steering angle end, good steering feeling can be maintained without reducing the driving current for correction. COPYRIGHT: (C)2008,JPO&INPIT |
