Force optimization of planar 2-DOF parallel manipulators with actuation redundancy considering deformation

Abstract

Internal force distribution is one of the most important issues for redundantly actuated parallel manipulators. This article presents a novel method for optimizing internal force to minimize the deformation of key components in a parallel manipulator. The dynamic model is first derived, and then an objective function is proposed by giving different weights on internal forces of different components based on its flexibility. The deformation of the component with big flexibility is minimized. A planar 2-DOF parallel manipulator with actuation redundancy is taken as an example to validate the force optimization method. The simulation results show that the deformation of the manipulator with the force optimization method proposed in this article is smaller than that with the traditional method to minimize the norm of driving forces. Thus, the manipulator precision can be improved.