Lightweight Multi-DOF Manipulator With Wire-Driven Gravity Compensation Mechanism

Energy consumption is a problem for robotic manipulators, which are popular in manufacturing, assembly, and process handling. Some of the most significant energy consumption comes from the weight of the large moving mass of the manipulator. This paper proposes a new multi-degree-of-freedom (DOF) manipulator with a wire-driven gravity compensation mechanism. The most significant problem of a wire system is the durability of the wire, which is improved in this study by using a multiwinding mechanism. The tension of the wire is reduced in proportion to the number of windings. Timing belts are used to design a multi-DOF manipulator and the lightweight gravity compensation mechanism reduces inertia forces during operation. Static analysis and design issues are presented. A robotic prototype is assembled and the torque-reduction performance is verified experimentally. The proposed mechanism can be applied to industrial manipulators for efficient robotic operation.