Design And Research Of Ankle Exoskeleton Based On Muscle Tendon Model And Energy Consumption Model

In recent years,the research and application of exoskeleton-powered robots have become more and more extensive and in-depth.In addition to the rehabilitation exoskeleton used in the medical field,more and more exoskeleton research teams are studying the exoskeleton of normal individuals to reduce the energy required by the user to complete an activity.This article takes the ankle exoskeleton as the research object,the main research includes the construction and application of the ankle joint biomechanical simulation framework,the energy consumption modeling of the ankle joint active exoskeleton and the design of the ankle joint exoskeleton.First,build an ankle joint ”exoskeleton-human body” biomechanical simulation framework based on the double-Hill muscle model.By simulating the morphology and energetics of the human ankle muscle and tendon,study how the exoskeleton reduces human metabolic energy.Simulate a passive linear exoskeleton to evaluate the biomechanics simulation framework,and compare the results with the simulation results of an ankle ”exoskeleton-human body” biomechanics simulation framework based on a single Hill muscle model.The simulation results have been improved to a certain extent.The deviation between the theoretical optimal stiffness of the passive linear exoskeleton and the experimental optimal stiffness is 3.3%,and the reduction rate of metabolic energy is the same as the experimental result.The reason for the improvement is that the double-Hill muscle model can better reflect the changes in muscle efficiency under assistive force conditions.Second,through the genetic algorithm and biomechanical simulation framework,explore the potential of the active exoskeleton in reducing the walking metabolic energy of the human body.The characteristic of ”less than proportional muscle torque when doing negative work”and ”post-peak torque phase”.This is because with the assistance of exoskeleton,the difficulty of muscle force generation and the required metabolic energy of muscle when the same muscle activation degree is completed have changed caused by muscle length and speed.Third,explore the influence of the elastic element and exoskeleton motor configuration position on the active exoskeleton energy consumption.Simulation found that the energy-saving principle of the exoskeleton and the energy-saving principle of the human muscle can be mutually confirmed.Whether the elastic element is used depends on the similarity of the exoskeleton torque and the displacement of the motor output.Through the simulation of the position of the exoskeleton motor,it is found that the exoskeleton with additional displacement is worse than the exoskeleton without additional displacement in terms of energy consumption and energy saving ratio.Finally,according to the simulation conclusions of the previous chapter,an ankle exoskeleton was built to study the potential of exoskeleton auxiliary torque with torque characteristics obtained by genetic algorithm in reducing metabolic energy.The constructed exoskeleton can avoid the interference of the exoskeleton assist force in gait recognition,and its assist force is better achieved.The total metabolic benefit measured by the cardiopulmonary function respirometer is 4.16 %,which initially proves that the auxiliary torque characteristics obtained by genetic algorithm have certain potential to reduce metabolic cost.