Design And Study Of Spherical Exoskeleton Robot For Human Shoulder Rehabilitation

With the arrival of the aging society and the improvement of people's living standards,robots will have significant application prospect in the field of medical rehabilitation and assisting the elderly and the disabled.The medical engineering cross research with substantial medical scientific research will be one of the important research directions of medical rehabilitation robots.Wearable exoskeleton robot,based on bionic principle and combined with ergonomics,can be worn on affected limbs.The shoulder joint is the main motion joint of the upper limb of the human body.The hemiplegic patients or shoulder injuries will directly affect people's daily life and work.Therefore,the rehabilitation treatment of stroke hemiplegia or injured shoulder joint is particularly important.This paper presents a spherical telescopic exoskeleton rehabilitation robot for shoulder rehabilitation training based on the physiological structure and movement mechanism of shoulder joint.This paper firstly analyzes the essence of mechanical rehabilitation training for hemiplegic limbs.Based on the physiological structure and movement mechanism of shoulder joint,the design and performance requirements of shoulder rehabilitation robot are put forward.Aiming at the design requirements and existing problems,the paper presents a spherical telescopic exoskeleton shoulder rehabilitation robot.The kinematics model of the spherical telescopic mechanism is established using coordinate transformation method.The forward kinematics and inverse kinematics are solved.The singularity is analyzed.Then the kinematics is simulated in combination with the motion mechanism of human shoulder joint.The displacement,velocity and acceleration curves are obtained.It is verified that the motion form of the mechanism can meet the requirements of shoulder motion.Then the Lagrange equation method is used to establish the system dynamics model of the shoulder rehabilitation mechanism.The dynamics simulation is carried out using ADAMS,which provides a theoretical basis for the trajectory tracking control analysis of the shoulder rehabilitation robot.Finally,considering that the movement precision of the rehabilitation mechanism will directly affect the effect of shoulder rehabilitation training,and even cause secondary injuries,in order to ensure the better stability and position control precision in the training process of the shoulder rehabilitation mechanism,the trajectory tracking control of the shoulder rehabilitation mechanism is studied.The independent PD control,the PD control with gravity compensation and the algorithm of calculating torque control evolved from PD control are analyzed.Considering that there are many uncertainties affecting the rehabilitation effect in the rehabilitation training process,the PD feedback control based on variable structure compensation and the PD feedback robust adaptive control algorithm are presented.The joint simulation platform of ADAMS and MATLAB is established.The above control algorithm is simulated jointly.The results show that the precision of PD feedback robust adaptive control algorithm can meet the requirements of shoulder rehabilitation training.