Statics and stiffness model of n( 3-RPS) serial-parallel manipulators

A statics and stiffness model of the n( 3-RPS) serial-parallel manipulator is established. First,the transfer relation of velocity for the n( 3-RPS) serial-parallel manipulator is analyzed based on the kinematics property. Second,the statics of n( 3-RPS)serial-parallel manipulator is solved based on the principle of virtual work. Third,the stiffness model of the n( 3-RPS) serial-parallel manipulator is established,and the deformation of this serial-parallel manipulator is solved. The finite element( FE) models of 2( 3-RPS) and 3( 3-RPS) serial-parallel manipulators are established,and the validity of the analytic model is verified by the simulation results. The methodology for establishing stiffness model of n( 3-RPS) serial-parallel manipulator is also suitable for other serial-parallel manipulators.