Contribution to the design optimization of redundant parallel robots

Abstract

This study investigates the design Enhancement of parallel kinematic manipulators (PKMs) with spherical linkages. The main goal is to enhance the robot's structural platform and to minimize joints deflection by utilizing kinematic redundancy. Firstly, a novel mathematical approach is proposed for modeling the desired SPM. This approach is based on Gosselin theory using the implementation of Euler's angles (orientation angles), which allows for modeling any type of Spherical Parallel Manipulator (SPM) by simply varying the desired robot's geometric parameters. The Advantage of this approach is to model any specific SPM platform by simply parameterizing the geometric parameters of the desired platform to the standard form model. Furthermore, a comprehensive stiffness analysis using Matrix Structural Analysis (MSA) validated through comparison with Virtual Joint Method (VJM) implemented in Matlab software. The study demonstrates and highlights the significant impact of redundancy on the kinematic and structural behavior of parallel structures. By leveraging kinematic redundancy (adding extra kinematic chains), leading to reduced robot joint deflection and enhanced stiffness. The incorporation additional kinematic chains, thus the manipulator manipulability and precision are improved, contributing to its overall performance. The findings underscore the significance of structural optimization and kinematic redundancy in advancing parallel manipulator design, with implications for a wide range of applications requiring precise and robust robotic manipulation