Abstract: The finite element theory is employed to investigate the theory and method for dynamics modeling of planar parallel manipulators with flexible links. The elastic displacements of the sub-chains and the relation between elastic displacements are analyzed. The kinematic constrain conditions and dynamic constrain conditions of the flexible parallel manipulators are proposed. Considering the effects of distributed mass, lumped mass, shearing deformation, bending deformation, tensile de-formation and lateral displacements, the kineto-elastodyna- mics theory and Lagrange formulation are employed to derive the dynamic equations of planar flexible parallel manipulators. The elastic vibration characteristics of the flexible planar par-allel manipulator are well illustrated through the numerical simulation of a planar 3-RRR parallel manipulator. The flexi-bility of links is demonstrated to have significant impact on position error and orientation error of the moving platform.

Key words: Dynamics, Flexibility, Model, Parallel manipulator