摘要 |
A stage system includes an object table constructed to hold an object, a short stroke actuator element constructed to displace the object table over a first range of movement, and a long stroke actuator element constructed to displace the short stroke actuator element over a second range of movement which is larger than the first range of movement. The stage system further includes a pneumatic compensation device including: a sensor arranged to measure a quantity representative of a pneumatic disturbance force on the short stroke actuator element, an actuator arranged to provide a compensating force to at least partly compensate the pneumatic disturbance, and a controller. The sensor is connected to a controller input of the controller, the actuator is connected to a controller output of the controller, the controller being arranged to drive the actuator in response to a signal received from the sensor. |