| 摘要 |
<p>PURPOSE:To attain highly precise and high speed positioning by using an air static pressure screw for transmission and inserting a filter into a control loop. CONSTITUTION:A motor 1 is directly connected to a screw shaft 2, a nut 3 where static pressure air is floated moves with the rotation of the screw shaft 2, and a stage 5 held by an air floating slider 4 translation-moves. A position detector 6 detects the position X0 of the stage 5 and it is returned to a position control part 7 as a feedback quantity. The control part 7 calculates a position deviation between a target position Xi which a target position generation part Cg generates and the feedback quantity X0 and calculates a PID output obtained by adding a proportional quantity, an integral quantity and a differential quantity as against the position deviation to quantities obtained by multiplying them by respective coefficients Kp, Ki and Kd. The calculated value is caused to pass through the filter F1 in which the gain is suppressed around a specified frequency, and is outputted as the driving voltage of the motor 1.</p> |
