A family of 3-PRPaR spatial translational parallel robots

This paper focuses on a family of 3-PRPaR spatial translational parallel robots whose the moving platform is linked to the base by three PRPaR topological limbs, and the P joint fixed in the base acted as a actuated one in each limb. A systemic approach is employed to find all possible parallel robots of this family. Firstly, two types of the PRPaR limbs and their normal subgroups are defined base on the geometrical relationships between the passive R joints and actuated P joint on the limb. Then, the assembly condition of three limbs is given by means of the concept of conjugate subgroup. According to the assembly condition and the proposed method in the reference, all parallel robots of this family are finally found and are classified as six subsets by the type of layout of three actuated P joints on the fixed base. Discover the proposed parallel robots with three PRPaR limbs in other literatures are special cases of this family. The analysis method of in this paper is used for finding other family of parallel robot when other type of topological limb is considered.