Data age reduction
AssigneeZygo Corporation
InventorFrank C. Demarest
Life of this patent
Estimating the term…
Abstract
Disclosed are method and electronic components for: i) electronically extracting a sequence of values from a measurement signal corresponding to a position of a moving object, wherein the sequence of values indicates the position of the moving object at corresponding time increments; ii) electronically determining at least one of an estimate for a velocity of the moving object and an estimate for an acceleration of the moving the object based on a plurality of the values in the sequence of values; and iii) electronically correcting a value in the sequence of values to substantially reduce the effect of processing and signal delays based on one or both of the velocity and acceleration estimates.
Claims34
A method comprising:
- a. electronically extracting a sequence of values from a measurement signal corresponding to a position of a moving object, wherein the sequence of values indicates the position of the moving object at corresponding time increments;
- b. electronically determining at least one of an estimate for a velocity of the moving object and an estimate for an acceleration of the moving the object based on a plurality of the values in the sequence of values;
- and
- c. electronically correcting a subsequent value in the sequence of values based on one or both of the velocity and acceleration estimates,
- i. wherein the velocity estimate is electronically determined and used to correct the subsequent value in the sequence of values to correct for a position error caused by a data age delay,
- ii. wherein electronically extracting the sequence of values from the measurement signal comprises electronically extracting phase values from a frequency of interest in the measurement signal and unwrapping the phase values to produce the sequence of values corresponding to the position of the moving object, and
- iii. wherein the method further comprises repeating the electronic determining and the electronic correcting to provide a sequence of corrected values indicating the position of the moving object at corresponding time increments that is corrected for position errors caused by data age delay in the electronic extraction of the sequence of values and/or acceleration-dependent electronic filtering errors, and applying an action to the moving object based on the sequence of corrected values.
An apparatus comprising an electronic processing module implementing one or more processors and configured to:
- a. electronically extract a sequence of values from a measurement signal corresponding to a position of a moving object, wherein the sequence of values indicates the position of the moving object at corresponding time increments;
- b. electronically determine at least one of an estimate for a velocity of the moving object and an estimate for an acceleration of the moving the object based on a plurality of the values in the sequence of values;
- and
- c. electronically correct a subsequent value in the sequence of values based on one or both of the velocity and acceleration estimates,
- i. wherein the velocity estimate is electronically determined and used to correct the subsequent value in the sequence of values to correct for a position error caused by a data age delay,
- ii. wherein electronically extracting the sequence of values from the measurement signal comprises electronically extracting phase values from a frequency of interest in the measurement signal and unwrapping the phase values to produce the sequence of values corresponding to the position of the moving object,
- wherein the apparatus further comprises a source for directing an energy beam to a certain location of the object based on the sequence of corrected values provided by the electronic processing module, a movable stage to support the movable object, and a stage controller for moving the stage, and wherein the electronic processing module is coupled to stage controller.
Dependencies are inferred from the claim text.