Research On The Design Of 3-DOF Sit-to-stand Assistive Device

With the aggravation of the aging phenomenon in China,the number of people with motor disorders caused by cerebrovascular diseases is increasing year by year.In daily life,they are often unable to complete the sit and stand conversion exercise independently,and usually need stand rehabilitation aids to help them to carry out sit and stand conversion.With the increasing demand for lower limb rehabilitation training equipment,more and more kinds of standing aids are used to assist standing.However,many standing AIDS only aim at completing the movement,and use a single movement track to assist sitting and standing conversion,which will lead to poor human-computer integration and cause secondary injury to the body of the disabled.Therefore,in order to improve the performance of the standing AIDS,this paper studies how to design the standing aids based on the rules of sitting and standing conversion movement of different percentile human body in normal state.In this paper,30 healthy subjects were selected as the research objects to analyze their sit and stand conversion exercise.The movement characteristics of different individuals in the transition period were compared.In order to reduce the probability of formation of solidified posture caused by poor human-computer integration,the way to design standing rehabilitation aids was explored.Referring to the experimental results,the scheme design,mechanism design and structure design of the stand rehabilitation auxiliary equipment were carried out.Finally,a three degree of freedom stand rehabilitation robot was designed,and the actual prototype processing and manufacturing,prototype test,finite element analysis,control system construction and structure optimization design were completed.In terms of the movement rules,this paper finds that some subjects have a transition period between the balance stage and the rising stage.According to the rules,it is suggested that the transition period should be considered when designing the standing rehabilitation aids,and the transition period should not be too long;when using the standing rehabilitation aids to complete the rehabilitation training,attention should be paid to the leg swing,release the leg freedom,and ensure that the standing track is more connected.The reference initial position and three hip joint reference trajectories selected according to the leg length were given.In the aspect of structure design,a three degree of freedom stand rehabilitation robot design scheme is proposed.The designed stand rehabilitation robot has the advantages of large range of motion,wide applicability,strong combination application and good human-computer integration.Adopting a more reasonable flexible support mode and the auxiliary standing strategy in line with the human motion law can better improve the rehabilitation effect.The above research provides a reference for the design of related standing rehabilitation aids.