Kinematics Analysis And Real Time Simulation Platform Research Of 3-SPR+4R Upper Limb Exoskeleton Hybrid Mechanism

Exoskeleton robot is a wearable robot,which is with the functions of operational assistance,body support,security protection,auxiliary operation.It can be used to enhance astronaut operation ability in space,which has a broad application prospects in the field of aerospace.At present,the relevant research mainly focuses on the less freedom of wheelchair-style rehabilitation skeletal robots,which are not meet the needs of astronauts.Therefore,a kind of upper limb exoskeleton hybrid mechanism for the specific wearing demand of astronaut space operation is designed,and the kinematics analysis of the hybrid mechanism,the co-simulation of trajectory planning and the real-time simulation platform of kinematic control model are studied.In this paper,combining the upper limb movement freedom with astronauts work requirements,a 3-SPR + 4R six degree of freedom(DOF)upper limb exoskeleton hybrid mechanism is designed and the main parameters of the mechanism are determined.The 3-SPR+R mechanism was adopted to achieve three DOF,which are adduction/outreach,flexion/extension of shoulder joint and the medial rotation/lateral rotation of the upper arm.The 3R mechanism was adopted to achieve the other three DOF,which are flexion/extension of the elbow,medial rotation/lateral rotation of forearm and flexion/ extension of wrist.The two parts are connected by a slip ring mechanism to realize the wearing.The kinematics analysis of the hybrid mechanism is carried out by the equivalent mechanism method and the partial solution method,and the advantages and disadvantages of the two methods are analyzed.Based on the kinematic characteristics of the 3-SPR parallel mechanism,the hybrid mechanism is equivalent to the series mechanism,the D-H coordinate system of the equivalent mechanism is established,and the variables are gradually separated to complete the forward and inverse solution.Based on the inverse kinematic solution of the parallel mechanism,the kinematic analysis of the four joints series part is solved by the partial solution method,and the kinematics analysis of the hybrid mechanism is completed.Then,the theoretical analysis are verified by ADAMS and numerical examples.The classification of trajectory planning method and common interpolation methods are analyzed,and the trajectory planning in joint space is carried out by the fifth order polynomial interpolation.The parametric simulation model of upper limb exoskeleton hybrid mechanism is established by ADAMS.The joint space trajectory planning control model of forward and inverse kinematic analysis is established by Simulink.Simulink is used as the control platform to carry out for co-simulation,and the motion control simulation of the upper limb exoskeleton is realized.Based on the advantages of simulation platform,a scalable simulation platform for upper limb exoskeleton hybrid mechanism is developed by using real-time software and hardware of NI.An interactive control interface is developed in LabVIEW,which can achieve the real-time control function of upper limb exoskeleton.And the foundation is laid for physical control of the upper limb exoskeleton.