Design And Experimental Study Of A Crab-like Exoskeleton Hand Function Assist And Rehabilitation Robot

With the aging of the population,the incidence of stroke in middle-aged and older people is increasing,which is one of the leading causes of disability in China.Stroke often causes hand motor dysfunction and seriously affects the daily life of patients,which is of great significance to the recovery of hand function in patients with stroke hemiplegia.The existing hand rehabilitation robots with rigid mechanisms have developed relatively maturely,but there are defects of large volume mass and low flexibility.The human-computer interaction safety of flexible hand rehabilitation robots is high,but there are defects of complex driving methods and low control accuracy.Therefore,this paper proposes a design method for a crab-like hand function assist and rehabilitation robot and conducts prototype development and experimental research.The specific research contents are as follows:(1)Rigid-flexible coupling mechanism design: inspired by the combination characteristics of rigid exoskeleton protection function and flexible muscle drive function in crab foot,this paper proposed a design method of a bionic rigid-flexible coupling exoskeleton mechanism.The finger driving mechanism is designed which realizes the rotation driving of the three finger joints by a single linear actuator through the coupling movement of a flexible thin-walled steel sheet and rigid parts.It has the advantages of compact structure and lightweight.At the same time,the external rigid parts protect the internal flexible steel sheet.Based on the design of the finger drive mechanism,we model and analyze the large deformation bending and rigid-flexible contact of thin-walled steel sheets in the rigid-flexible coupling mechanism.The rigid-flexible coupling multi-body dynamics simulation and structural parameter optimization are carried out to make the parameters of the rigid-flexible coupling mechanism meet the design requirements of the robot.(2)Multimodal perception and motion control: different sensors are used to collect data of forearm surface electromyogram(EMG),finger bending angle,and actuator working current during rehabilitation training to realize motion monitoring of patients during rehabilitation.Based on the hierarchical investigation of the stroke rehabilitation stage,the passive and active training methods in exercise rehabilitation training were studied.The active and passive rehabilitation training modes of the rehabilitation robot were designed based on the sensor data.At the same time,the immersion and participation of the patients in the rehabilitation training were improved by providing visual feedback on the hand movement data in the training process.(3)Prototype and experiment: The prototype system of the hand function-assisted rehabilitation robot is designed and implemented.The test of the finger space motion range,the compliance test of the rigid-flexible coupling mechanism,and the test of active and passive rehabilitation training modes are carried out.The results show that the motion range of the rigidflexible coupling mechanism can meet the daily activities of human hands,has good passive compliance,and has high safety in the process of the robot wearing and assisting human hands.In the passive rehabilitation training mode test,the rehabilitation robot can drive the subjects’ hands well to carry out passive bending training.At the same time,in the active rehabilitation training mode,the grasping process of the rehabilitation training can be controlled according to the patients’ autonomous grasping motion intention.