Design And Research Of 2-dof Transfer Assistive Device And Its Human-Computer Interaction

The development of my country’s population aging trend and the increase of disabled groups have become increasingly serious social problems.The elderly generally suffers from decreased physical function and inconvenience in daily activities.For the elderly with insufficient lower extremity muscle strength and the disabled with lower extremity movement disorders,sit-to-stand conversion is a challenging exercise in daily life,and Long-term wheelchair or bedridden life accelerates muscle decline.Regular sit-to-stand conversion training and standing activities can delay the decline of physical function to a certain extent,and can also enhance the patient’s self-confidence.Therefore,this thesis studied the design of transfer assistive device,aiming to help the target population complete the sit-to-stand conversion exercise and the later walking rehabilitation training,thereby reducing the work pressure of nursing staff.In this thesis,30 healthy adult subjects were randomly recruited to investigate the effect of the anterior-posterior position of the armrests and feet on the kinematics and dynamics of sit-to-stand transitions under the knee support,and the relationship between motion posture and stability.In order to make the movement of the transfer assistive device conform to the natural motion law of the human body,a two-degree-of-freedom motion mechanism was proposed.Through the forward and inverse kinematics analysis of the mechanism,the size parameters and motion posture of the mechanism were obtained,and the trajectory planning of the end effector of the mechanism was carried out.On the basis of the mechanism design,ergonomic analysis was carried out,and ergonomic transfer assistive device were designed.The dynamic analysis of the transfer assistive device was carried out,the mechanism of human-machine coupling motion was studied,and the law of man-machine coupling motion was obtained.The linear drive thrust was calculated,and the type and thrust of the linear drive were selected.On the basis of the structural design,the appearance design of the transfer assistive device was carried out.The appropriate material was selected for the transfer assistive device,the overall shape was carried out,and three color schemes were proposed.Finally,for users with different physical conditions and different needs,the rehabilitation guidance functional modules of unconstrained training,constrained training and full-course auxiliary training were designed,the IDEF0 model of the rehabilitation training guidance system was established,and the user interface of the rehabilitation training guidance system was designed.The experimental results showed that the closer the feet were to the seat,the smaller the peak moment of the hip joint,and the greater the peak moment of the ankle and knee joints.When the armrest was far away,the trunk anteversion angle was larger,and the total moment impulse of the lower limb joints was smaller.Based on the experimental results of sit-to-stand conversion,a transfer aid was designed,and the motion mechanism of the transfer assistive device could make the end effector walk out of the sit-to-stand trajectory that conforms to the law of human motion.The linear drive selected according to the law of human-machine coupling motion could meet the motion requirements of sit-to-stand.The designed rehabilitation training guidance system could carry out sit-to-stand rehabilitation training guidance for users with different physical conditions,so that the user’s posture and actions during the sit-to-stand process conform to the sit-to-stand motion law of the human body.