| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an electric power steering device capable of stably controlling motor current all the time even if voltage applied to a motor for steering assist is increased or lowered. <P>SOLUTION: The electric power steering device is provided with the motor 18 for steering assist driven by a motor drive circuit 13 applied with voltage of an on-vehicle battery P, determines target motor current to be made flow in the motor 18 based on detected steering torque applied to a steering member and determines a motor current command value by feedback control (22) so as to make the determined target motor current flow in the motor 18. The electric power steering device drives and rotates the motor 18 by the motor drive circuit 13 based on the determined motor current command value, detects rotational frequency of the motor 18, and increases or lowers voltage of the on-vehicle battery P in accordance with the detected rotational frequency. The electric power steering device is further provided with a means (13) for detecting voltage applied to the motor drive circuit 13 and a change means (20) for changing a control gain of the feedback control (22) in accordance with the detected voltage. <P>COPYRIGHT: (C)2008,JPO&INPIT |
