| 摘要 |
<P>PROBLEM TO BE SOLVED: To execute the original point positioning of a stepping motor with excellent accuracy even if a bounce-back phenomenon occurs. <P>SOLUTION: The stepping motor is driven from the state of the full opening of a valve. The first time butting is executed at the time shown by an arrow A. Then, the stepping motor steps out. A movable body bounces back by the distance of an arrow Y. Continuously, a motor control unit calculates the distance of the arrow Y. It obtains a number of driving command pulses required for the second time butting. It drives the stepping motor. The second time butting is executed in a time shown by an arrow A' in the stepping motor. Also in this case, the stepping motor steps out. The movable body bounces back by the distance of an arrow Y'. The same operation as the second time is repeated even after the third time. The butting operation is finished when a bounce-back amount shown by the arrows Y, Y' and Y'' becomes below a prescribed threshold. Thus, the original point positioning is completed. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
