| In 2017,the number of peasant workers in labor-intensive industries such as manufacturing and construction in China has reached 147.55 million.Although the degree of mechanical automation has gradually increased,and there are professional handling equipment for heavy and large objects,workers still need to engage in repetitive operation of10-20 Kg heavy objects for a long time.This long-term repetitive operation eventually leads to that lumbar disease becoming a major health problem for such workers.Therefore,the paper aims at the lumbar spine disease of labor workers,aiming at the protection of lumbar vertebrae,starting with the exoskeleton boost,taking the lumbar spine force as the research object,and inspired by the analysis of the biomechanical characteristics of human lumbar vertebrae movement,a passive energy storage exoskeleton mechanism is proposed to make full use of the gravitational potential energy of human trunk and improve the utilization rate of human energy.The main research work and innovations are as follows:(1)This topic firstly carried out research on the biomechanical properties of human lumbar vertebrae,taked the human body lifting heavy objects as the research action,and established a biomechanical model.Then the static and kinematic biomechanical analysis of human lumbar spine was carried out successively.The changes of pressure and moment of lumbar spine L5/S1 in the process of lifting heavy objects were obtained,which provided a comparison for the subsequent verification of the labor-saving effect of exoskeleton mechanism on lumbar spine.The data provide a theoretical basis for the research of exoskeleton mechanism assistant methods,and also provide a set of research methods and a certain research basis for other human biomechanics research;(2)According to the biomechanical revelation of human lumbar vertebrae,this paper proposes three different assisting methods based on spring energy storage components,and analyzes and compares them through dynamic simulation.Based on the final selection of assisting method,a passive energy storage exoskeleton mechanism is designed,and the kinematics model and mechanics model of human wearing exoskeleton are established,to provide a mathematical model basis for the stepwise search method to optimize the spring parameters of the energy storage component;(3)In order to improve the auxiliary protection effect of the exoskeleton mechanism on the lumbar vertebrae,two optimization methods based on static modeling and dynamic modeling were applied in this paper,respectively,to optimize the parameters of compression spring stiffness,supporting position at upper edge and tension spring stiffness and supporting position at upper edge of energy storage element.The correctness of static and dynamic modeling simulation were cross-validated,and the final optimization parameters of energy storage components were determined.Based on the final parameters,the optimization effect was verified by dynamics.The effective moment of L5/S1 of lumbar spine was reduced by57.3%,and the contractual force was reduced by 27.2%.The results showed that the optimization effect of parameters of spring energy storage components was obvious;(4)At the end of the project,the prototype of passive energy storage exoskeleton mechanism was fabricated.The simulation and experimental verification were carried out to evaluate the good auxiliary protection effect of the exoskeleton on the lumbar vertebrae.At the same time,a comprehensive evaluation method of human lumbar spine is established,which is applied in vitro measurement and in vivo measurement.The comprehensive evaluation method of human lumbar support effect is used to provide reference for the evaluation of human lumbar vertebrae and even other joints and muscles of the human body. |
PDF Full Text Request