Accuracy and repeatability analysis of industrial robot under loaded conditions and various distances

Abstract

The increasing usage of industrial robots in manufacturing operations is due to its flexibility and its ability to be reprogrammed easily when the old task changes. Robotics is a branch of modern technology which synergizes knowledge in engineering fields namely mechanical, electrical, electronics and control. The main obstacle in robotics applications is to minimize the positional errors when it is under real working conditions. Robots have to perform accurately under loaded conditions at any locations within the working envelope. The aim of this research is to evaluate the performance of an industrial robot under payloads and locations within its working envelope. Relationship between the location and payload versus accuracy and repeatability are to be obtained using laser interferometry. Experimental work and statistical analysis were carried out to achieve the desired objective of the project. The study of linear performance had shown that the six-axis COMAU robot under study has a linear accuracy of 0.783 mm. The recorded repeatability of 0.003 mm is better than the specified value of ±0.05 mm given by the manufacturer. Statistical analysis shows that the load factor has a significant effect on the repeatability of the robot.