Investigations of temperature-induced errors in positioning of an industrial robot arm

Analysis of the influence of the temperature on the positioning accuracy of the robot arm is one of the key problems in robotic assembly operations. The results of the analysis of the industrial robot positioning error presented in the article show that in conditions of stable temperature, these errors are systematic. Research on the influence of ambient temperature on the accuracy of the robot positioning was carried out for selected points in the working space of the robot arm. The Lillefors distribution was used to determine the influence of temperature on the distribution of the random variable. The results obtained were subjected to statistical analysis using the Shapiro-Wilk test. It was shown that to calculate the value of total error, the three-sigma rule may be used, because the flat normal distribution is concentrated around its expected value. Knowledge of the structure of the total error of the robot makes it possible to determine the location where the process can be carried out in which the robot has the least sensitivity to temperature-induced errors.