抄録
In the field of Electron Beam Lithography apparatus disliking leakage of magnetic flux and heating, it is intended that air actuators are used instead of electro-magnetic actuators. However, due to the pneumatic compressibility, the settling time becomes long. The more the positioning gain is set large, the more the positioning system becomes unstable. To overcome this unstable phenomenon, it is well-known that the closed loop is stabilized using the parallel feedforward compensator (PFC). In order to realize the higher speed positioning, in this paper, the pressure feedback is implemented in the closed loop in addition to the series compensator induced from the equivalent transformation of PFC. Moreover the first-order differential to manipulate the stiffness, the disturbance observer, and the second-order differential to manipulate the damping are added. Under this control scheme, the feedforward compensator functions effectively. Using a pneumatic experimental apparatus, remarkable positioning results can be shown.
