Design And Control Method Of Lower Limb Exoskeleton Rehabilitation Robot System

As China’s access to the 21st century,the trend of aging population intensifies.What is more,aging will lead to more brain neurological cerebrovascular diseases.As a result,limb motor dysfunction and other sequelae of the number of patients also increase year by year.The current effective treatment for such patients is a large and systematic rehabilitation exercise.Lower limb assisted exoskeleton robot technology is a new emerging technology in recent years.It can help patients with rehabilitation training.And it is a combination of robot technology and traditional rehabilitation medicine.For stroke caused by hemiplegia and other diseases,patients in the recovery process usually experience weakness,spasm,and recovery of three stages.Different strategies should be used in different stages for different people.In the early rehabilitation,patients with weak activity,rehabilitation training should be basically a passive traction.So the patient needs to be driven by the lower limb rehabilitation robot to carry out the passives rehabilitation training.However,in the later stage of rehabilitation,the patient has certain active motor ability.And with the assistance of the lower limb rehabilitation robot,the patient can carry out certain active rehabilitation training.Related studies have shown that when the patient in the active rehabilitation training,the patient’s related nerve damage can be better recovery.In this paper,the corresponding rehabilitation strategy is proposed for the different rehabilitation stages of patients with lower limb hemiplegia.In this paper,kinematics and dynamics models of lower limb rehabilitation robots are established by using D-H parameter method and Lagrangian equation method.The kinematics and dynamics models are validated by using Matlab simulation model.And the position of the ankle joint and the relationship between the angles of the joints are analyzed.Thus,it provides theoretical basis for motion control.Normal human gaits are collected by VICON optical motion capture system.After a series of treatment,and finally gait reference trajectories are got.On the basis of this,for the early rehabilitation,passive rehabilitation training is carried out by gait trajectory tracking.In the middle and late stages of rehabilitation.The active training mode of traditional lower limb rehabilitation robot is to add impedance control in control and adjust impedance parameters according to different stages of rehabilitation,which will increase the difficulty of operation.And it is not conducive to the promotion of limbs.Based the traditional fuzzy impedance control method,this paper proposes a new active assistant training method based on fuzzy adaptive impedance control.When the patient in the rehabilitation training,different stages of the feedback force is different.According to the feedback force information,the controller will adjust the impedance parameters online so that patients can better participate in training.Finally,an experimental platform for external skeletal rehabilitation robot for lower extremities was built.And a real.time system framework based on Matlab simulink real.time is constructed.Furthermore,the passive and active rehabilitation training experiments on the treadmill and the ground are carried out to verify the safety of the system.As well as the rationality of the control method meets the desired requirements.