System and method for on-the-fly eccentricity recognition
AssigneeBrooks Automation, Inc.
InventorMartin Hosek
Life of this patent
Estimating the term…
Abstract
A method of substrate eccentricity detection includes includes determining at least three positions on a perimeter of a first substrate, grouping the at least three perimeter positions to define one or more circles, estimating a location of a center of the first substrate as the location of a center of a predetermined circle approximated from the at least three perimeter positions, and determining an eccentricity vector as a difference between the estimated location and a reference position on a substrate transport mechanism on which the first substrate rests.
Claims39
A method of substrate eccentricity detection comprising:
- determining at least three positions on a perimeter of a first substrate as the first substrate is moving along a transfer path;
- estimating a location of a center of the first substrate as the location of a center of a predetermined circle approximated from the at least three perimeter positions;
- and
- determining an eccentricity vector as a difference between the estimated location and a reference position on a substrate transport mechanism on which the first substrate rests.
A method for determining the eccentricity of a first substrate comprising:
- capturing a position of a mechanism upon detection of each of at least three points on a perimeter of the first substrate while the mechanism is transporting and moving the first substrate;
- compensating the captured positions for detection delays;
- converting the transport mechanism positions to positions on the perimeter of the first substrate;
- estimating a location of a center of the substrate as the location of a center of a predetermined circle approximated from the perimeter positions;
- and
- determining an eccentricity vector as a difference between the estimated location and a reference position on the substrate transport mechanism.
A method for determining the eccentricity of a substrate comprising:
- moving the substrate through a field of view of one or more sensors to detect at least three points on a perimeter of the substrate;
- capturing a position of a mechanism upon detection of each of the at least three points while the mechanism is moving the first substrate;
- compensating the captured positions for detection delays;
- converting the transport mechanism positions to positions on the perimeter of the substrate;
- grouping the perimeter positions into trios, each trio defining a circle;
- estimating a location of a center of the substrate as the location of a center of a predetermined circle approximated from the perimeter positions;
- and
- determining an eccentricity vector as a difference between the estimated location and a reference position on the substrate transport mechanism.
A system for substrate eccentricity detection comprising:
- a substrate transport mechanism for transporting a first substrate along a path;
- at least one sensor for sensing points on a perimeter of the first substrate as the first substrate is moving along the path;
- and
- a controller connected to the substrate transport mechanism and to the at least one sensor, operable to:
- determine at least three positions on the perimeter of the first substrate determined when the at least one sensor detects a perimeter of the first substrate;
- estimate a location of a center of the first substrate as the location of a center of a theoretical circle which is approximated from a set of the at least three perimeter positions;
- and
- determine an eccentricity vector as a difference between the estimated location and a reference position on the substrate transport mechanism.
A system for substrate eccentricity detection comprising:
- a substrate transport mechanism for moving a substrate along a path;
- at least one sensor having, a centerline positioned eccentric to the path for sensing points on a perimeter of the substrate as the substrate is moving along the path;
- and
- a controller connected to the substrate transport mechanism and to the at least one sensor, operable to:
- determine at least three positions on a perimeter of the substrate when the at least one sensor detects the perimeter of the first substrate;
- estimate a location of a center of the substrate as the location of a center of a theoretical circle with a radius equal to a nominal radius which is approximated by a set of the at least three perimeter positions;
- and
- determine an eccentricity vector as a difference between the estimated location and a reference position on the substrate transport mechanism.
Dependencies are inferred from the claim text.