Assembly conditions of parallel manipulators considering geometric errors, joint clearances, link flexibility and joint elasticity

This paper presents a methodology to analyze the assembly conditions of parallel manipulators and compute the maximum pose errors of their moving platform, while considering geometric errors, joint clearances, link flexibility and joint elasticity. First, the proposed methodology consists in determining the zone(s) of the manipulator workspace in which the manipulator can be assembled assuming that its links and joints are rigid, while taking into account geometric errors and joint clearances. Then, the minimum energy required to assemble the manipulator in the non-assembly zone(s) is computed, while considering link flexibility and joint elasticity. The maximum pose errors of the moving-platform are also computed throughout the manipulator workspace. Finally, a two-dof spatial parallel manipulator, named IRSbot-2, is used as an illustrative example.