Rotational axes and inverse kinematics analysis of a novel 5-DOF hybrid manipulator

This paper presents a novel five-degree-of-freedom (DOF) hybrid serial-parallel manipulator (HSPM). The parallel part of this HSPM is 2UPU/SP parallel mechanism (PM), and this PM has two rotational DOF and one translational DOF (2R1T). To better understand the structure, the principle of constructing the HSPM is introduced. As this parallel part belongs to an overconstrainted 2R1T PM, the constraint force/torque generated to the moving platform are analyzed. Incidentally, the rotational axes of the PM is obtained, which is helpful to well know its motion properties. Then inverse position of the HSPM is deduced. And to make it more geometric visualization, the reachable workspace of the PM is given. At last, numerical simulation involving five axis linkage processing is done, and the results show the correct of theoretical model. This research will lay good theoretical foundations for application of this novel manipulator.