| 摘要 |
<p>PURPOSE:To make the return of a handle constant irrespective of the change of the motor characteristics by not feeding the current to an electric motor in a braking region where the handle is returned in the direction opposite to the rotating direction of the electric motor. CONSTITUTION:A torque detector 10 detecting the steering torque, a vehicle speed detector 11 detecting the vehicle speed, and a motor rotation detector 12 detecting the rotating direction of an electric motor (m) are connected to a motor control unit D. The electric motor (m) engaged with a rack 4 via a reduction gear 9 is controlled in response to the output signal of the motor control unit D. Whether a handle 1 has been returned or not is judged based on the rotation signal from the motor rotation detector 12 and the output torque signal from the torque detector 10. If the handle 1 has been returned, no current is fed to the electric motor (m). Accordingly, the drive force of the electric motor (m) does not become the resistance against the rotation of the handle 1, and furthermore, this is true even if the motor characteristics are changed due to heat or the like.</p> |
