Design and Development of a Single-Motor, Two-DOF, Safe Manipulator

This paper presents the design and development of a novel two degrees-of-freedom safe robot manipulator. Magnetorheological clutches are incorporated in the design to enable antagonistic actuation at the joints. A single unidirectional motor supports bidirectional actuation of all joints. Unlike most current safe robots, high-quality actuation is preserved, while the manipulator weight and effective inertia are reduced. This is achieved by relocating the driving motor to the base of the robot. Moreover, magnetorheological clutches have been shown to pose superior torque to mass, and torque to inertia characteristics over conventional servo motors, further contributing to the reduction of manipulator mass and inertia. The manipulator exhibits both high performance and intrinsic safety as a result of mechanically passive dynamics. A set of experiments is performed to validate the manipulator performance.