Abstract: Based on the merits of pure serial manipulators, such as large working space and simple kinematic forward solution, also the characteristics of pure parallel manipulators, which include high rigidity and better carrying capacity and simple kinematic inverse solution, as well as the fruits about serial-parallel hybrid manipulators overseas and inland, still practical requriements in manufacutring process involved, a new type of universal Cartesian serial-parallel manipulator is presented. 6-DOF(degree of freedom) output shaft between upperlayer and underlayer platform is obtained by linear actuation. Workspace in shape of four-prism or three-prism is established by analytic geometry method, singular structure of mechanism and the shape of singular workspace presented. Litmits of swinging angle of output shaft at given configuration in 3D space are acquired by analytic method. Several groups of inverse solution of position with universal meaning are obtained. Further analyses indicate that there are three groups of solution satisfing the requirements when the output shaft is parallel to the vertical guideway, five groups of solution exist if the output shaft is not parallel to the vertical guideway.

Key words: Analytic method, Degree of freedom, Inverse solution, Serial-parallel manipulator, Workspace