| Lower extremity load-carrying exoskeleton can match human body,expand lower limb motor ability,reduce load and torque of human.Because heavy,short using time and bad adaptability,the traditional exoskeletons cannot be used in the mountains,hills and other difficult terrain.This paper putting forward a kind of closed-chain lower extremity load-carrying exoskeleton with energy storage element.Besides,according to the energy storage strategy,energy storage element was added to improving human walking effect.Without external drive,exoskeleton can assist people catching heavy things and walking long distance.Firstly,according to the body fitness put forward three primary lower extremity exoskeleton models.Through the ADAMS simulation and the analysis of the models to determine the final design of lower extremity exoskeleton.The final design is composed of main frame and energy storage element,also design the structure of the exoskeleton movement scheme.Secondly,using closing-vector-circle method and MATLAB to analysis the statics of lower extremity exoskeleton and human body.Combining walk features and lower extremity exoskeleton analysis,this article design element energy storage as a variable stiffness spring with pre-tightening force.In a gait cycle,taking total effective minimum torque of human legs as the goal,and optimizing the spring stiffness by gradually search method.Finally,using ADAMS dynamics simulation to verify the correctness of mathematical model for extremity limb exoskeleton and manufacturing the first prototype machine according to the structure design.Under 20kg/(40kg)load,the exoskeleton can transfer 95% /(80%)of the load weight to the ground,reduce 13.4%/(11.9%)of the effective torque of human joints.Without drive,human experimental results are shown that the extremity limb exoskeleton can reduce human walking consume.Also,it improves the traditional exoskeleton problems of short using time,poor adaptability,small carrying capacity,poor dynamic performance,heavy and high energy consumption. |
