Research On Design And Experiment Of Powered Backpack For Reducing Human Metabolic Cost During Load-carrying Walking

Load carriage is a very important daily activity in human life.It is especially common among students,travelers and soldiers.Carrying a heavy load will cause a sharp increase in metabolic consumption and increase the risk of human musculoskeletal damage.How to eliminate and mitigate these negative effects and improve the quality of life is a research hotspots at present.Based on the analysis of the carrying load phenomenon in nature,the idea of regulating the vertical movement of load to reduce the metabolic energy consumption of load carriage is put forward in this paper.By using engineering technology and combining with human kinesiology,a design method of powered backpack to reduce the metabolic energy consumption of walking with heavy load was put forward and verified by experiments.The research results of this paper provide an innovative solution for reducing the metabolic energy consumption of carrying load.The main research work of this paper includes:(1)On the basis of the biomechanical analysis of the carrying load phenomena in nature,the idea of actively regulating load movement to reduce the metabolic energy consumption is proposed.Specifically,two auxiliary strategies are proposed,namely eliminating the inertia force of the load by controlling the acceleration of the load in the vertical direction and regulating the anti-phase motion between the load and the human trunk in the vertical direction.The design method of the powered backback combining active system(motor,lead screw)and passive system(elastic rope)is put forward.The design scheme of mechanical system and control system of powered backpack is established,and the experimental scheme of using unilateral powered backpack and bilateral powered backpacks to verify two auxiliary strategies is determined.(2)Through the kinematics and dynamics analysis of the powered backback,the model of the powered backback is established,and the parameters of the model are obtained through the systematic identification by the experimental method.To solve the disturbance problem in acceleration control,a disturbance observer(DOB)based control method and an iterative learning control method are introduced.(3)Developed unilateral powered backpack and bilateral powered backpacks,completed the circuit design and integration of the control system.The hardware design of the control system is completed to make the system autonomous,and the design of the embedded software and the PC software of the control system is completed.(4)Experimental verification of the powered backpacks was carried out.The unilateral powered backpack and the bilateral powered backpacks were used to verify two kinds of auxiliary strategies,eliminating inertial force and anti-phase motion.The experimental results show that it can effectively reduce the metabolic consumption of human load carriage during walking.