关键词: 并联构型装备, 静刚度

Abstract: By taking the 3-DOF parallel mechanism within the Tricept robot as an example, an analytical approach is presented, which enables the stiffness of the PKM having a properly constrained passive limb to be quickly estimated within the entire workspace. This approach can be implemented by three steps: ① Decomposition of the end-effector’s deformations into the tensile/compression deformation of the unconstrained active UPS limbs, and the torsional and bending deformations of the properly constrained UP limb. ② Formulation of the stiffness model of each subsystem by means of virtual work principle and structure matrix method. ③ Generation of the compliance model of the entire system by linear superposition. The static stiffness distributions of the 3-DOF parallel mechanism of the Tricept are depicted in a spherical coordinate system, and the contributions of the component compliances to the system compliance is evaluated by using global performance indices.

Key words: Parallel kinematic machine, Static stiffness