6-DOF Hybrid Cable-Driven Parallel Robot with an Articulated Manipulator

Realizing both dexterity in a large workspace and mechanically efficient architecture is a challenge for robotic manipulators. Conventional industrial robots, including serial and parallel robots, have suffered from the trade-off between the weight and the size of the workspace. On the other hand, cable-driven parallel robots (CDPRs) perform excellent lightness of the platform in a large workspace. However, its workspace is surrounded by a box, which leads to a large occupied space. This paper presents a hybrid cable-driven parallel robot with an articulated manipulator. The end effector is a platform whose orientation is directly controlled by four cables. The proposed architecture realizes 6-DOF motion by a light body. Since the tendons do not go through the intermediate joints of the articulated manipulator, the mechanical efficiency of the cables is improved compared to conventional tendon-driven robots. The forward kinematics is analyzed, and the numerical solution using the Newton-Raphson method is derived. The position control method, considering the statics of the platform, is explained. The experiments of position control confirm the performance of both translational and orientational motion.