| 摘要 |
<p>PURPOSE:To eliminate heavy movement of a steering wheel when it starts to turn at low speed by taking a factor of vehicle speed not only into assist current but also into differential compensation current and decreasing the differential compensation current smaller as the speed rises. CONSTITUTION:In a controller 30 for controlling power supply to an electric motor 7 for rotating a pinion engaged with a rack of a steering mechanism, an assist current determination circuit 31 and a differential compensation circuit 32 which receive output signals of a vehicle speed sensor 14 and a torque sensor 15 respectively are provided. According to an assist signal SA for obtaining assist current which increases with an increase in a steering torque and decreases with an increase in vehicle speed and a differential coefficient which is set so that it gradually decreases as the vehicle speed increases, the steering torque and a differential compensation signal so for obtaining differential compensation current according to the vehicle speed are output. After both signals SA,SD are summed 34, they are input to a motor driving circuit 33 to be applied to a motor 7 as driving current.</p> |
