| In human daily life,walking with load is a very common activity.How to develop an exoskeleton device that can effectively assist the body’s load-carrying movement and enhance the body’s ability of load-carrying with scientific methods,not only has important academic value,but also has important practical value.Among the several exoskeleton devices currently available in the world,active exoskeleton cannot fully match the humanmachine movement due to the difficulty in accurately analyzing the movement intention of the human body;passive exoskeleton is mostly used to assist the body’s own movement and cannot transfer the load of the heavy backpack to the ground.In this thesis,by analyzing the motion law of the lower limbs during the human walking process,and based on a new type variable stiffness joint with adaptive variable stiffness characteristic which can be induced by impact.we proposed a design method of passive load-carrying lower limb exoskeleton and a variable stiffness joint embedding mechanism that can be passively induced by human motion.And on this basis,we developed an exoskeleton device which can effectively assist the body’s load-carrying movement.The research results of this thesis have achieved innovative results in the field of load-carrying lower limb exoskeleton,providing a new idea for the design of load-carrying exoskeleton.The main research contents of this article are:(1)Research of the gait law of human lower limbs walking: Starting with the walking process of human,we analyzed the kinematic laws of gait,joint motion angle and other dynamic laws of the human body during walking,as well as the dynamic laws of ground reaction force and lower limb stiffness.On this basis,we also analyzed the influence of walking with load on the law of human lower limb movement,which laid the foundation for the design of the load-carrying lower limb exoskeleton.(2)Embedding mechanism of variable stiffness joints and construction of exoskeleton principle model: Based on a variable stiffness joint with variable stiffness characteristics designed by a smart material,combined with the research and summary of the analysis of the movement of the human body’s lower limbs,we proposed the embedding mechanism of the variable stiffness joints that can be passively triggered by human movement.and finally completed the analysis of the design principle of the passive load-carrying lower limb exoskeleton and construction of principle model.Then,we used the simulation software ADAMS to establish the model of load-carrying exoskeleton and the human body and perform walking simulation.Simulation verifies the validity of the design principle of the load-carrying exoskeleton.(3)Development of lower limb exoskeleton device: Based on the analysis of the hip and knee joint movement in walking and the variable stiffness characteristics of variable stiffness joints,we proposed the layout of the variable stiffness joints at the hip and knee joints,and a clutch was designed as a purely mechanical control mechanism which can convert the reciprocating swing of the knee joint into one-way linear motion.Finally,comprehensive design requirements such as exoskeleton working principle,human wearing comfort,and lightweight exoskeleton structure were considered,we designed the passive weight-bearing lower extremity exoskeleton device.(4)Wearing experiment and auxiliary effect verification of exoskeleton device: Based on the lower limb exoskeleton device,we used equipment such as motion analysis system,plantar pressure measurement system,and EMG signal measurement system to build an experimental platform,and a scientific experimental paradigm was designed in consideration of factors such as human-computer interaction and subject differences.Then we carry out the experiment,by measuring and analyzing the human joint motion angle and plantar reaction force and EMG signal to comprehensively evaluate the auxiliary effect of the lower extremity exoskeleton device. |
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