The geometrical analysis of the robotic mechanisms means the formulation of the position equation of the mechanism in terms of dependent and independent coordinates. This function should describe the position of its links and the end effecter (or moving platform center) in terms of dependent and independent coordinates.In this paper will be derived a mathematical model, that is, a model in terms of
dependent and independent generalized coordinates, for the position accuracy of the end effecter (platform) of the closed kinematics robotic mechanisms. In these types of mechanisms it is necessary to solve the inverse problem of the geometrical analysis. The
solving of the inverse problem in the robotic systems means the definition of independent coordinates on preset values and evaluation of the dependent coordinates with several degrees of mobility.
The aim of this paper is to obtain a new mathematical formulation for evaluation of the deviation of the end effecter position due to the deviation of the independent coordinates. It will be evaluated only the deformations of the arms caused by the weights and the forces.