| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a motor control device which can increase the motor output, while suppressing motor current variation resulting from voltage variations due to dead time control. <P>SOLUTION: An electric motor 3, which imparts power for supporting the steering to a steering mechanism 2, is controlled by a motor control device 5. The motor control device 5 controls the electric motor 3 by controlling the d-axis current and the q-axis current on the dq coordinates. A dq-axis current command value computing section 26 sets a q-axis current command value i<SB>qa</SB><SP>*</SP>, based on the steering torque and the vehicle speed, compares it with the q-axis current upper-limit value and the q-axis current lower-limit value and then limits the q-axis current command value i<SB>qa</SB><SP>*</SP>, depending on the comparison results. Furthermore, the dq-axis current command value computing section 26 determines the d-axis current command value i<SB>da</SB><SP>*</SP>, based on the q-axis current command value i<SB>qa</SB><SP>*</SP>thus limited. The q-axis current upper-limit value and the q-axis current lower-limit value are determined, based on the voltage variations caused by dead time control. <P>COPYRIGHT: (C)2009,JPO&INPIT |
