Patent ID: 11858147
Assignee: KAWASAKI JUKOGYO KABUSHIKI KAISHA
Field: Handling (Mechanical engineering)
Classification: CPC B  H  G | IPC B  H

Claim 9:
10. A substrate transfer robot, comprising:
a robot body comprising:
a hand configured to hold a substrate;
a robotic arm configured to displace the hand; and
a photoelectric sensor at a tip-end part of the hand;

a substrate placing part at a substrate placement position; and
a controller comprising a processor programmed to:
define an ideal optical axis in the hand;
define a position in the hand vertically overlapping with a center of the substrate held by the hand, as a hand center;
operate the robot body so that the hand is advanced to the substrate placement position in a horizontal second direction perpendicular to a horizontal first direction in a posture in which the ideal optical axis extends in the first direction, the substrate being transferred from the hand to the substrate placing part at the substrate placement position;
operate the robot body so that the hand is moved from the substrate placement position to a position retreated in the second direction by a distance obtained by adding (i) a radius of the substrate to (ii) a distance between the hand center and the ideal optical axis;
operate the robot body so that the photoelectric sensor performs a first search for an edge of the substrate while advancing and retreating the hand in the second direction;
obtain a position of the hand in the second direction when the hand is at the retreated position, as a reference position;
obtain a position of the hand in the second direction when the edge of the substrate is detected by the first search, as a first detected position; and
detect a positional deviation of the optical axis from the ideal optical axis based on a difference between the reference position and the first detected position.