Construction of Interactive Kinematic Spatial Mechanism and Robot Models Through GeoGebra Software

This study presents procedures and guidelines for using the popular Dynamic Geometry Software (DGE) GeoGebra to create highly interactive simulations of mechanisms and robots towards educational and research purposes. The goal is to introduce and demonstrate the tool to develop self-explanatory constructions designed to present important topics, namely, the spatial posture, the graphical solution of the position analysis of mechanisms of serial and parallel manipulators, the Denavit-Hartenberg (DH) proximal convention, the homogeneous transformation matrices, and the hypothetical closure link method for serial manipulators. Seven constructions are illustrated: the interactive coordinate system construction, the 1-degree of freedom (DOF) position analysis of a spherical four-bar mechanism, the inverse analysis of a 4-DOF Schönflies parallel platform with three universal-prismatic-universal legs, and four constructions for the 6-DOF General Electric P60 (GE-P60) serial robot. The first of these four constructions deals with the direct position analysis via the graphical method. The second one offers a detailed explanation of the DH parameters. The third one uses the DH parameters to obtain the homogeneous transformation matrices for solving its direct position analysis. Finally, the fourth construction solves the hypothetical closure link and the inverse position analysis of the serial robot. The results are interactive computer simulations accessible via hyperlinks, encouraging users to explore the constructions, to use them as a cornerstone for their own constructions, and enhance the topics comprehension. The authors envision these simulations as an effective tool to communicate the knowledge about mechanisms and robots.