Kinetostatic Modeling and Analysis of a New 3-DOF Parallel Manipulator

This paper proposes an innovative design for a parallel manipulator that can be applied to a machine tool. The proposed 3-SPS-1-S parallel manipulator has three pure rotation degrees of freedom, including three SPS Active Legs and one passive constraining leg. The passive leg is introduced into this new parallel manipulator in order to increase the stiffness of the system and eliminate any unexpected motion. In this paper, the geometric model of the manipulator is introduced, and then the inverse kinematics and velocity equations are developed. Afterwards, a new kinetostatic model of the mechanism is presented based on lumped flexibilities theory. Subsequently, the global stiffness,which considers the compliance of links and joints is formulated and the kinetostatic analysis is conducted using a program prepared in MATLAB, and examples are given.