Stiffness Analysis of The 4-DOF Parallel Manipulator with Compound Spherical Joints

A novel 4-DOF parallel manipulator with compound spherical joints is introduced. Its characteristics are analyzed according to the structure of the mechanism. In order to measure the influence of constraint force on the stiffness of the parallel manipulator. The 4-DOF parallel manipulators with compound spherical joints is equivalent to 6-DOF parallel manipulators. The kinematic model of the equivalent PM is built by vector method. Then the Stiffness model of the 4-DOF parallel manipulators is constructed. A finite element model of this parallel manipulators is constructed and the simulation solutions are obtained. The correctness of the stiffness model is verified, which provide the theoretical and technical foundations for its application.