Error Compensation of a Large Scale LCD Glass Transfer Robot

Abstract

A new generation LCD (liquid crystal display) technology requires the bigger size of raw glass in order to supply the demand for a large size TV. Samsung Electronics Company has built the world first 7th generation LCD plant and also recently 8 th generation LCD plant. In order to handle bigger and heavier glass, a large scale LCD glass transfer robot is necessary. This robot requires precise path accuracy in order to improve stack efficiency of glass cassette which affects the productivity of LCD plant. But it is difficult to meet the requirement of accuracy because the deflection and deformation of structural components to bear the large dynamic loads deteriorate the accuracy of the robot. This paper presents a method of improving the vertical path accuracy by kinematic compensation for the deflection without any increase of structural stiffness. Firstly, the LCD transfer robot and its requirements are introduced. Next, flexible multi-body dynamic model to simulate the deflection and deformation under dynamic loads is established. Then the idea of improving the path accuracy is presented. Finally its optimization problem is solved using DOE (design of experiment) method.