| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an electric power steering device for preventing the drop of a power voltage by reducing power consumption depending on a power voltage value. <P>SOLUTION: The vector control of a d-q axis is used for computing a current command value on the basis of at least steering torque T, and an electric motor 12 is controlled to be driven on the basis of the current command value. At this time, when a vehicle speed V reaches a predetermined vehicle speed V1 or lower, a d-axis current command value Idref in the vector control is computed to be smaller as a battery voltage Vbat is lower. Thereby, when the battery voltage Vbat is high, normal weak field control is executed to improve a steering feeling during abrupt steering, and when the battery voltage Bbat is low, weak field control is developed to be weaker than usual one to reduce power consumption and reduce the drop of the battery voltage. <P>COPYRIGHT: (C)2009,JPO&INPIT |
