Loading patent…
AssigneeNikon Corporation
InventorsPai-Hsueh Yang, Michael B. Binnard, Scott Coakley
Estimating the term…
An exemplary stage assembly has movable stage mass and counter-mass. A stage motor is coupled to the stage mass and counter-mass such that stage-mass motion imparted by the stage motor causes a reactive motion of the counter-mass counter to the motion of the stage mass. At least one trim-motor is coupled to the counter-mass. A control system commands the trim-motor to regulate movement of the counter-mass in reaction to stage-mass motion. A PI feedback controller receives the following-error of the counter-mass and generates corresponding center-of-gravity (CG) force commands and trim-motor force commands to the trim-motor(s) to produce corrective counter-mass motion. A trim-motor force limiter receives trim-motor force commands and produces corresponding limited trim-motor force commands that are fed back as actual CG force commands to the feedback controller to modify integral terms of the feedback controller according to the limited trim-motor force commands.
A stage assembly, comprising:
In a stage assembly including a movable stage mass, a counter-mass movable in reaction to motion of the stage mass, and at least one counter-mass trim-motor, a method for controlling motion of the at least one counter-mass trim-motor, the method comprising:
In a precision system including a stage having a movable stage mass coupled to a counter-mass such that movement of the stage mass causes reactive motion of the counter-mass relative to the stage mass in a direction opposite to a direction of movement of the stage mass, a method for controlling the direction of motion of the counter-mass, comprising:
Dependencies are inferred from the claim text.