Development of a Continuous Verticalpulling Automatic Doffing Robot for the Ring Spinning Doffing robot is an important part of the spinning process in the textile production. This paper analyzes the doffing process of spinning machines and points out the requirements of the structure and functions of the doffer. The locking twofinger gripper, the threedimensional circulating operation mechanism, the collaborating locating mechanism with the toothed disc and the preloosening mechanism by rotating spindles are designed. On this basis the continuous verticalpulling automatic doffing robot, named CVP doffing robot, for the ring spinning is developed. The kinematics and dynamics analysis of the CVP doffing robot are carried out. The structural parameters of the CVP doffing robot are optimized by establishing kinematics and dynamics models. The forces of pulling out cops before and after the preloosing operation are tested. On this basis, the strength of the key components is designed and checked. Finally, the performance of the CVP doffing robot is verified by the doffing experiment.

Modeling and Force Control of Robotic Polishing System for the Wheel Hubs Polishing is a key step in the manufacturing of wheel hubs since it will affect the appearance and performance of the wheel hubs. In this paper, a robotic polishing system is designed for the wheel hubs. To facilitate variable selection and controller design, the polishing process is firstly modeled. A roughness model considering the classic Preston material removal model is proposed. The roughness model aims at controlling the surface roughness rather than the material removal of the workpiece, which is more suitable for the robotic polishing for the wheel hubs. Then, a positionforce hybrid control framework is proposed for the robotic polishing system. To improve the performance of the force control, a threelevel rulebased adjusting method is designed and robot motion trajectory is planned based on the resolution surface of the wheel hubs. Finally, polishing experiments on the wheel hubs are fully conducted to demonstrate the effectiveness of the proposed modeling and control method of this paper.