Kinematic Analysis of a New 3T1R Parallel Manipulator

Parallel manipulators are known to have higher structural rigidity and end-effector speed than serial manipulators. However, the size, payload, rigidity, and repeatability of parallel manipulators highly depend on the types of active and passive joints used. Compared with other joint types, revolute joints are structurally simpler and have an unlimited rotation range. They can be easily preloaded to increase the stiffness and eliminate clearance. Hence, revolute joints are preferable for parallel manipulators that need to have a smaller size, larger payload, and higher reparability. This paper presents a new parallel manipulator that uses only revolute joints as the active and passive joints. This parallel manipulator can generate three translational motions and one rotational motion. The kinematic analysis is provided to facilitate the design of the new parallel manipulator. We expect that the proposed parallel manipulator can provide an alternative for selecting parallel manipulators to meet different industrial applications.