Comparative study of the parametric and analytical model of the movement of PR-02 robot arm

The work presented in this paper concerns selected results obtained in the search for a parametric model of the movement of the end of PR-02 robot arm. The research performed involved a critical review of the literature on the subject, design and implementation of a parametric robot model, and carrying out simulations and a comparative study. First of all, it was necessary to obtain data for identification-based modeling, which result from the assumptions and experiments on the functioning of the analytical model of the movement of the end of PR-02 robot arm. Therefore, based on the functioning of the analytical model, a set of numerical data needed to identify the movement of the end of PR-02 robot arm was generated. Using the input and output data of the analytical model of the PR-02 robot arm end-motion system, additional data were generated from the environment of individual parameter values as input quantities and the coordinates of points on the motion trajectory as output quantities, within the limits of the permissible accuracy error of the individual data, in order to obtain sufficiently large amounts of data for the purposes of obtaining a parametric model of the system by identification. The obtained data were then used in identification using the ARX method to generate an identification-based model. In the preparatory research process for the research experiment, three sets of data were generated, differing in the length of the experiment duration, but always for 3 output quantities representing the coordinates of the position of the point on the trajectory of the end of the PR-02 robot arm. The data set, for which the most accurate ARX model was obtained, was adopted in the identification experiment, conducted on the simulation model in Simulink. Then, an appropriate model was built to perform the necessary simulations and comparative tests, meant to determine whether and to what extent the parametric model is sufficiently accurate. The comparative studies used absolute and relative errors between the analytical model and the parametric model. Moreover, the discrepancies between the trajectory plotted by the analytical model and the one plotted by the parametric model were examined, and the obtained results were discussed and conclusions and directions for further research were formulated.