Static analysis and design of a 3-DOF spherical parallel manipulator

Static analysis plays an important role on the design and applications of manipulators. In this paper, the torque balance equations of a 3-DOF spherical parallel manipulator are derived. Then the torque transmission capacity evaluation index and the global index are defined and discussed in detail on the base of the torque balance equations. At last, the geometrical parameters of the spherical parallel manipulator are optimized based upon the global index, other performance capacity evaluation indices and technics. The research results of this paper provide the theoretical base for the design and applications of the 3-DOF spherical parallel manipulator and the prototype of a mechanical shoulder based upon the 3-DOF spherical parallel manipulator has been developed in our Lab.