Development of a Vector Geometrical Model for PKM Identification

Abstract

Geometric accuracy of parallel kinematic machine tool is an issue that limits their use in challenging context such as the aeronautic. One way to improve their accuracy consists at improving their geometrical identification process. For this purpose, a new geometric modeling method on the vectorial modeling of joint invariants is proposed in this article. This method introduces only independent geometric parameters and guarantees the robustness of the identification process. The studied machine-tool structure is modeled with links connected by joints. The geometrical end-effector pose is defined relying on geometrical defects and joint degrees of freedom. This new methodology is applied to an Exechon-like parallel kinematic machine tool, the Tripteor X7.