Topology design and performance optimization of six-limbs 5-DOF parallel machining robots

Abstract

The core components used in frontier fields typically have complex surface topography, difficult-to-remove workpiece materials, and extremely high machining quality and efficiency requirements. These characteristics pose major challenges to the performance of machining equipment. To address these issues, a class of six-limbs five degree of freedom (5-DOF) parallel machining robots with high stiffness and flexibility is designed. To cope with the coupling effect of multi-type parameters of robots on the optimal design, a comprehensive optimal design method combining mechanism theory and engineering experience is proposed. This method includes topology synthesis, layout evolution, performance design, and structure selection. Three performance indices, namely, stiffness, transmissibility, and mass, are considered. Two novel layouts and six novel prototypes have been optimized. Through the quantitative comparison and qualitative analysis of the above results, the influence of different layout and topology on the structure and performance of the robot is discussed, and several potential application scenarios are presented. The numerical simulation demonstrates that the designed six-limbed 5-DOF parallel robot exhibits satisfactory static behavior and flexibility, fulfilling the essential requirements for complex component machining.