Graduate Research Papers


Open Access Graduate Research Paper


With the increasing application of robots to many fields in our life, the accuracy and the repeatability of robots become more and more important. Many applications require robots to have high repeatability and accuracy. There are many factors which can affect the repeatability and the accuracy of a robot.

This study was to examine how the two key factors of payload and speed affect repeatability. The experiment was conducted in the CAM Laboratory of the Industrial Technology Center, University of Northern Iowa, by using Microbot TeachMover. Six different payloads: 2gm, 20gm, 65gm, 130gm, 180gm and 250 gm, and three different speeds: speed(3), speed(5) and speed(?) were exerted under the control of the same program. The robot with certain payload and speed ran 30 cycles, and the spatial positions were measured by three dialindicators which represented three-dimensional coordinates (X,Y,Z). After the data were collected, the relative spatial position deviation was calculated. The first cycle point was used as the original position. The researcher used the mean of the spatial position deviation and the range of spatial position deviation to analyze the affect of payloads and speeds on repeatability. Also linear trend "b'' and the coefficient of correlation "r'' were used to identify repeatability change during the 30 cycles. Analyzing the collected data led to the conclusion that light payload and medium speed have better repeatability, and both higher speed (7) and lower speed (3) lead to lower repeatability.

Year of Submission


Degree Name

Master of Arts


Department of Industrial Technology

First Advisor

Douglas Pine


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Date Original


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