| 摘要 |
<p>PURPOSE:To improve accuracy of detecting a middle point by detecting a steering mechanism for its steering position detecting the middle point of the steering mechanism when steering torque is smaller than a steering torque preset value, set in accordance with a car speed, further when an angular speed is smaller than an angular speed preset value. CONSTITUTION:Output signals of a torque sensor 6, speed detector 17 and a car speed detector 18 are input to a control part 7, when steering torque is placed in a dead band, a middle point arithmetic routine is executed. That is, whether or not the car speed is larger than a threshold value is decided and, when the car speed is larger than the threshold value, a torque preset value is determined in accordance with the car speed and compared with a torque detection value. When the torque detection value is smaller than the preset value, an angular speed preset value is determined in accordance with the car speed and compared with an angular speed detection value, and when a vehicle is in straight advancing with the angular speed detection value smaller than the preset value, the number of times with the corresponding comparing result is smaller, is counted. An addition value, obtained by adding a rotary position of a motor 8 in that time to a sum of the rotary position up to the preceding time, is divided by the number of counted times, obtaining a steering angle middle point.</p> |
