Yeon  Taek oh, 
    Influence of Geometric Error on Accuracy of Industrial Robot,
    Journal of Engineering and Applied Sciences,
    Volume 13,Issue 7,
    2018,
    Pages 1877-1887,
    ISSN 1816-949x,
    jeasci.2018.1877.1887,
    (https://makhillpublications.co/view-article.php?doi=jeasci.2018.1877.1887)
    Abstract: The study proposed a technique to analyse robot’s geometric error by using the data measured
during circle contouring movement of the industrial robot end effectors. Each joints of the industrial robot must
be set at a right angle to be able to move the robot’s end effectors to an intended position when an off line
program is used. However, the robot joints do not form a precise right angle, the end effectors occurs position
error when the robot is under operation. To analyze the angle error of the robot joints (i.e., datum location error),
the position measured during circular contouring of the end effectors is used. The shape of the measured circle
is also applied to analyze gear transmission error. The study carried out a simulation to find out that datum
location error and gear transmission error are the important error factors for accuracy of articulated robots.
    Keywords: robots;error characteristic;gear transmission error;datum location error;circular contouring;Geometric error