Kinematic modeling of a 5-DOF parallel mechanism for semi-spherical workspace

This paper presents the architecture synthesis and the kinematic modeling of a new five-degree-of-freedom parallel manipulator. The proposed mechanism is a 3T2R device intended to position and orient a line in space. It has been originally designed for a medical application in which the aforementioned line corresponds to the axis of a surgical needle. The mechanism is characterized by an asymmetric arrangement of its legs and wider mobility ranges than usually obtained with a parallel structure. Its inverse and forward kinematic models are derived, together with the assembly modes complying with the practical limitations of the mechanism.