Kinematic optimization for isotropic stiffness of redundantly actuated parallel manipulators

A kinematic optimization procedure for redundantly actuated parallel manipulator is developed to ensure the isotropic antagonistic stiffness in a workspace. The kinematic parameters of the mechanism are optimized to maximize and equal out antagonistic stiffness of the redundantly actuated manipulator when size and shape of the usable workspace are given but position in the entire workspace is not. The proposed procedure is verified with a 2-DOF planar manipulator by experiments. The experimental results show that the proposed procedure is useful for designing the redundantly actuated parallel manipulator with isotropic antagonistic stiffness in a predefined usable workspace as a design constraint.