| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress deterioration of steering property when an upper limit value exists in a drive voltage of a motor in an electric power steering device. <P>SOLUTION: In a vehicle 10 provided with an EPS 200, an ECU 100 executes steering control. In the steering control, when a motor rotation speed ω, i.e., a rotation speed of an assist motor 206 is larger than an upper limit rotation speed ω1 determined according to a motor instruction voltage Vq, i.e., a drive voltage of the assist motor 206, the effect that the assist motor 206 is in the power generation state is determined. When the assist motor 206 is in the power generation state, the ECU 100 controls a relay part of a drive device 208 for driving the assist motor 206 into the release state to shut off energization to the assist motor 206 and makes an amount of power generation to zero. In resetting to the assistable state, the assist torque Tm is gradually varied from zero as an initial value so as to prevent rapid variation of assist torque Tm. <P>COPYRIGHT: (C)2010,JPO&INPIT |
