A rotary parallel manipulator: modeling and workspace analysis

In this paper, a class of parallel manipulators known as Rotary Positioners (RP) will be analyzed. A Rotary Positioner is actuated by six circular motors on the circular base and does not involve any prismatic joint. Therefore, it has constant length limbs. A model of an RP is presented. The constraints related to passive joints and links interference are formulated and the workspace of a normalized RP is computed accordingly. The optimal combination of the main parameters for maximizing the workspace volume of the RP is also given.