| 摘要 |
<p>PURPOSE:To improve the returning characteristic of motor power steering device by adding a motor current command in returning direction to a motor current command in assisting direction upon reaching to specific steering angle. CONSTITUTION:When returning to straight advance travel after completion of steering, operating force of steering wheel is brought to zero thus to bring the torsional torque of steering shaft to zero. If the steering angle is larger than theta at this moment, the characteristic of the control circuit will be as shown by dot line. Consequently, left ward output as shown by itheta is produced and the motor will produce the output in returning direction of steering wheel. When the steering angle theta, the motor current command in returning direction will gradually approach to zero thus to move the characteristic of control circuit upward in parallel from the condition shown by dot line. Upon returning to the linear advance position, said characteristic will return to the condition shown by solid line.</p> |
