The Research Of The Structure And Control Methed Of Finger Rehabilitation Robot

The hand rehabilitation robot is an important part of medical robots,also is a powerful complement to the rehabilitation robot for the large joints of the upper limb,and the main role play by the hand rehabilitation is to assist the hand movements functional disorders to conduct the flexion/extension exercise rehabilitation training of their fingers,to help patients recover part of the hand movement function.Based on the rehabilitation theory research,we designed a SEA based hand rehabilitation in this paper,and concentrated on the kinematics analysis,parameter optimization of the series elastic actuator(SEA)as well as the force control method research,the impedance control method research and the research of the fuzzy control method which based on limb state evaluation.(1)Based on the analysis of the biological structure and kinematic characteristics of human's hand,by using the D-H method we established the kinematic model of four fingers of hand,expect the thumb for it is different from the others.And then we analyzed the trajectory of the human index finger's flexion / extension movement,by using the image processing technology,to lay the foundation for the structure design and control method research.(2)In terms of the rehabilitation robot mechanical structure design,mainly including two aspects: executive part design and drive part design.Execute part adopts the 3D printing method to the exoskeletons manufacturing,this greatly reduces the weight of the whole structure;and designed a series elastic actuator(SEA)as the driving part,to increase the flexibility of the system.And focused on the kinematics analysis and validation of exoskeleton,the experiments have been carried out to verify the feasibility of the model,finally.(3)On the basis of the model of the series elastic actuator(SEA)model,the analysis of the characteristics of output impedance and the force control performance analysis were carried out,and the analysis results show that the output impedance of the system is lower for the introduction of the elastic element,meanwhile provided evidence for the selection of parameters of the springs and the control parameters.At last,the simulation experiments also verified the adopted cascade force control method can meet the requirements.(4)Combined with the design of structure we put forward force based impedance control method,and established the Simulink simulation platform,and has carried on the low impedance and high impedance simulation experiments.Experimental results show that,by chosen the impedance parameters,the rehabilitation robot designed can realize both low impedance and high impedance two kinds of patterns,and show different compliances.(5)To overcome the disadvantages of the continuous passive motion(CMP),we put forward the fuzzy control method based on limb condition assessment,and the corresponding fuzzy controller was designed.Through the extraction of limb movement characteristic parameters and fuzzy inference and decision making,we can re-planning the speed for the rehabilitation training.The simulation results show that his control method can reduce the trajectory deviation and reduce the amplitude of the human-computer interaction force,at the same time,can increase the safety of the rehabilitation training and show more humanization.