Structural error correction method for SCARA robot

Abstract

An origin of a robot coordinate system is determined exactly as a center of a circular arc described by actuating a first axis only thereof and marking at least three points on a horizontally arranged sheet, at which an origin of an absolute coordinate system is set. In order to obtain the relationship between two coordinate system, making the both origin coincide with each other, then two y axis symmetrical points are measured to determine y axis. Then another two points are measured to obtain structural errors. Using structural errors, compensation of a numerical instructed point is carried out to make the robot position with high accuracy. Further, in order to remove backlash of the driving system, an intermediate point is set on a route toward a certain positioning point so that the driving system always rotates in one direction by some amount when moved to the final, aimed point.

Dependencies are inferred from the claim text.