Parallel Wire Mechanism for Gravity Compensation with Variable Elastic Force

In the development of the multi-DOF manipulator, we focused on the structure of passive exoskeletons, and proposed the new gravity compensation using parallel wire mechanism and springs. The novelty of the proposed gravity compensation is that the low-inertia mechanism with parallel wire can achieve the challenge of passive exoskeletons of the relation between the multi-DOF and the increase of the inertia. Also, in the proposed method, springs for gravity compensation are attached apart from the main body of manipulator, which can change the elastic force to compensate the weight of the manipulator in large range. We conducted the experiment with the manufactured manipulator with the proposed gravity compensation, and discussed the effectiveness of the proposed gravity compensation and the potential when assuming the exoskeleton application.