Kinetostatics Modeling and Analysis of a Spherical Parallel Continuum Manipulator

Abstract

In this paper, a spherical parallel continuum manipulator (SPCM) which is the flexible version of the 3-RRR“Agile Eye” mechanism is proposed and analyzed. The SPCM consists of three parallel flexible limbs, each limb is formed by compliant truncated cone elements, and the moving platform connects each limb with a passive revolute joint. Three servo motors are used to control the manipulator actively, and the spherical motion is realized by the coupled large deflections of the flexible links. An equivalent compliance analysis method of the element is developed based on finite element analysis and principal axis decomposition. By combining all three limbs, the kinetostatics model of the whole manipulator is derived, and a gradient iteration algorithm is developed to solve the forward and inverse kinetostatics. Finally, a prototype of the manipulator is constructed using 3D-printing technology, and the accuracy for element equivalence and end-effector characteristics is validated by experiments. The results show that the derived kinetostatics model can accurately describe the force–deflection behavior of the SPCM.