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In this paper, the concept of the "robust arm configuration" is expanded by using a mode-shape compensator. This compensator improves the robustness of the arm configuration where the robustness is not high enough. The compensator consists of a constant gain matrix and acceleration of each joint. The structure is simple and easy to use. The design method for this mode-shaping matrix is presented, based on the previously proposed mode-shaping algorithm. Effect upon the manipulability is also examined. It suggests that inclining of the dynamic manipulability ellipsoid's principal axes by the compensator, resulting in changing the coupling rigid body dynamics, leads to the improvement of the robustness. The validity is confirmed by a numerical example and experiments. The experiments are performed with an experimental system consisting of a two-degree-of-freedom (DOF) planar manipulator and a 1-DOF flexible base. A high bandwidth positioning is realized with the obtained compensator.