摘要：In order to satisfy the requirements of large workspace and high dexterity for processing equipment of oversized cylindrical boxes′spherical crown surfaces in the aerospace industry,a novel serial-parallel hybrid processing robot mechanism is *** degrees of freedom of the 5PUS-(2UR)PU parallel mechanism are obtained by using the screw *** inverse kinematics of the hybrid mechanism are analyzed and the velocity Jacobian matrix is ***,the constraints of the main factors influencing workspace of the mechanism are given,and the position and posture workspace are ***,the dexterity and stiffness performance of the mechanism is analyzed based on the Jacobian *** virtual prototype is established,and the theoretical calculation and simulation analysis of the hybrid mechanism with arc curve as the processing trajectory are carried out by using Matlab and Adams *** research results show that the mechanism can satisfy the requirements of large workspace and high dexterity of oversized cylindrical boxes′spherical crown surface processing,and has feasibility and practical application value.

摘要：This study aims to introduce a novel hybrid design with a combination of two more common mechanisms for improving the capacity of systems in absorbing the kinetic energy of moving vehicles or devices. This new model consists of two individual mechanisms, i.e., expansion of a circular tube accompanied by crushing of an inner tube, which dissipate the energy through friction, plastic deformations and failures of inner tube. This study comprises 24 case studies surveyed under two different design controls, constant mass and constant volume, for comparing purposes. Finite element simulations are utilized so as to investigate models’ deformations and to extract some crashworthiness parameters in aid of representing the efficiency of the mechanism as well as conducting a parametric study between three different profiles of inner tube. This study shows that models with inner circular and hexagonal tube profile absorb higher amount of energy due to experiencing three different modes of energy dissipation systems, including folding, shear and ductile damages.