On the Kinematics and Dynamics of 3-DOF Parallel Robots with Triangle Platform

In the first part of the paper a structural study of two types of 3-DOF parallel mechanisms with triangle platform is reported. A comparison between their geometric models is performed. Kinematics and dynamics using Newton-Euler formalism for a concrete case of 3-RRS parallel structure used for orientation applications (TV satellite antenna or sun tracker) are presented. In order to get the drive torques, which are necessary to overcome the frictions from the joints, the principle of virtual power is applied. The algorithms and simulation results for the workspace and singularities generation are provided. Diagrams for the dynamics representation are computed by means of numerical and graphical simulations.