Patent ID: 7630059

Claim:
A control system configured to control a position parameter of a stage in a lithographic apparatus, the control system comprising: a stage controller configured to control a position parameter of the stage in at least a first direction; a disturbance torque estimator configured to estimate a disturbance torque on the stage about an axis extending in a second direction, the second direction being substantially perpendicular to the first direction; and a correction signal calculator, the correction signal calculator adapted to receive the estimated disturbance torque and a signal representative of a position of the stage in a third direction, the third direction being substantially perpendicular to the first and second directions, the correction signal calculator configured to determine a feedforward correction signal to correct a position error of the stage in the first direction due to the disturbance torque using the estimated disturbance torque and the signal representative of the position of the stage in the third direction, the feedforward correction signal to be fed to the stage.