Position Control And Simulation Of Lower Limb Exoskeleton Robot

The lower extremity exoskeleton robot is a human-machine collaboration assisting device that combines human body bionic technology and robotics technology.It combines human environmental perception and motion decision-making capabilities with the mechanical performance of the robot,enabling humans not only to give full play to their subjective initiative but also to have the power and durability of the machine at the same time,improving the wearers' physical function,and is widely used in military,medical,industrial production,and assisting mobility.The humanmachine coupling is the key to the full use of exoskeleton robot functions.This requires the exoskeleton to accurately determine the wearer's movement intention in real time,and quickly and accurately drive the joints to complete the following movement.This paper formulates control strategies and designs feasible motion control algorithms for the lower extremity assisted exoskeleton model of the research group.The main research contents include:By analyzing the feasibility of the exoskeleton control method,position control is adopted as the control strategy of the exoskeleton robot.Based on human anatomy,the movement mechanism of the lower limbs of the human body is analyzed,the type,number and layout of the sensors are determined,and the gait data acquisition system of the lower limbs is designed to collect the joint angle data of the lower limbs under the normal state of human walking as the expected angle of exoskeleton position control.To improve the poor adaptability of PID control algorithm in position control and unsatisfactory accuracy of exoskeleton motion control,the combination of PID and fuzzy theory and variable universe is adopted to design a variable universe fuzzy PID control with good adaptability and accuracy Algorithm,and Matlab/Simulink is used to complete the design of the exoskeleton robot variable universe fuzzy PID controller.Through using Adams software to create an exoskeleton man-machine collaborative simulation environment,combined with Simulink to complete the exoskeleton mechanical model collaborative simulation,the feasibility of the designed variable universe fuzzy PID controlleris verified.The simulation results show that the exoskeleton joint response speed is fast,the overshoot is small,and the adaptability is strong when the variable universe fuzzy PID control is adopted,which improves the position control accuracy of the lower limb assisted exoskeleton robot and the dynamic response performance of the system.The feasibility of the designed variable universe fuzzy PID control algorithm is verified.