Design Of Flexible Lower Limb Exoskeleton Based On Pneumatic Muscle

Aging of the population is an important feature of modern society.With the aging of population,decline in human functions brings many problems such as action inconvenience.As a kind of electromechanical-hydraulic integrated equipment,lower limb exoskeleton has attracted much attention since last century.The application of exoskeleton is not only conducive to solving the problem of action inconvenience for the aging population,but for healthy people,exoskeleton can also reduce labor consumption and burden on laborers relying on boosting effects.With the advancement of technology,the development of exoskeleton has undergone a change in driving power from hydraulic to motor driving.The application of electronic technology has also increased the automation of the exoskeleton’s power-assisted behavior,and power-assisted efficiency has also been greatly improved.However,the common defect of hydraulic drive and motor drive is that the overall quality of the exoskeleton system is heavy,and the application of various rigid rods is not conducive to the improvement of wearing comfort.Therefore,this paper designs a flexible lower limb exoskeleton driven by pneumatic artificial muscles.The overall weight of the exoskeleton is light and wearable comfort is greatly improved.This thesis studies the kinematics characteristics of the joints of the lower limbs,and obtains necessary data for driving the joints by analyzing the driving force and driving torque of the joints of the lower limbs.In order for the exoskeleton to better fit the human body’s own motion rules,this paper collects the joint angle change data and plantar pressure data of the lower limbs of human body by using inertial sensing units and membrane pressure sensors,and analyze the details of the walking cycle.Aiming at the problem of diversification of human motion patterns,this paper also proposes an improved KNN-based data classification algorithm to analyze and recognize human motion patterns through the collected joint angle data and plantar pressure data.The overall recognition rate is relatively high.Since the response of pneumatic artificial muscles is non-linear,this paper summarizes existing research and proposes an improved model of pneumatic artificial muscles.On the basis of making the pneumatic artificial muscle and measuring its mechanical properties,the fuzzy PID control algorithm is used to control the power assist behavior of the pneumatic artificial muscle.In this paper,a small electric control box is also built.The overall weight of the driving part and the electric control box is light,and the driving part and the electric control box are detachable,and the exoskeleton is highly wearable.Through the actual walking experiment,the flexible exoskeleton in this paper has a boosting effect,and compared with the motor drive,hydraulic drive,etc.,the wearing comfort is greatly improved.