Patent ID: 8279401

Claim:
A position control system configured to control a position of a movable object, the system comprising: a position measurement system configured to measure a position of the movable object with a sensor and a sensor target, the sensor being arranged on the movable object and the sensor target being substantially stationary, or vice versa, the position measurement system configured to output a measured position signal representative of the measured position of the movable object; a comparator configured to provide an error signal; a controller configured to provide a control signal based on the error signal; a feed-forward device configured to provide a feed-forward signal based on a first signal related to a desired position; one or more actuators configured to act on the movable object based on the control signal and the feed-forward signal; a compliance compensator configured to provide a compliance compensation signal, and a module configured to receive the measured position signal and the compliance compensation signal and provide a feedback signal based on the measured position signal and the compliance compensation signal, the feedback signal to be received by the comparator, wherein the error signal is determined using a set-point position signal, the measured position signal, and the compliance compensation signal.