Design And Analysis Of An Adjustable Elliptical Trajectory Lower Limb Rehabilitation Robot

Due to the aging of the population,diseases,disasters and other reasons,there are more and more patients with motor dysfunction.Rehabilitation robots are one of the effective ways to treat such patients.Based on the study of the normal gait rule of the human body,this paper designed a lower limb rehabilitation robot with an elliptical training trajectory.The size and orientation of the robot training track can be adjusted to meet the rehabilitation needs of different patients or the same patient at different times.The main research contents of this paper are as follows:Firstly,according to the law of gait movement of lower limbs,the overall design scheme of rehabilitation robot was determined.On the basis of understanding the structural characteristics of the lower limbs of the human body,experiments were designed to explore the regularity of the normal gait movement of the human body.The test results show that the gait trajectories of the human body walking upright and sitting and squatting are all elliptical,but the size and orientation of the trajectory are different.According to this,the trajectory of the elliptical trajectory adjustable lower limb rehabilitation robot was planned,and the design requirements of the elliptical trajectory adjustable lower limb rehabilitation robot were proposed.Through the comparison and analysis of multiple schemes,the overall design scheme based on the planetary ellipse mechanism was determined,and the human-machine model was analyzed to obtain the factors affecting the joint angle.Secondly,the mechanical part of the elliptical trajectory adjustable lower limb rehabilitation robot was designed.The elliptical trajectory adjustable lower limb rehabilitation robot is mainly composed of a power mechanism,a transmission mechanism,an actuator and a frame.Emphasis was placed on the design of the transmission mechanism,the elliptical planetary mechanism,including the designs of the crank and the gears.The crank was designed as a variable mechanism.By changing the position of the collinearity between the crank and the planet carrier,the orientation of the elliptical training trajectory is changed,and the length of the elliptical training trajectory is changed by changing the length of the crank.The design of the rack and pedal mechanism and the selection of the power mechanism were briefly explained.Then,the elliptical trajectory adjustable lower limb rehabilitation robot was simulated and analyzed.The simulation model was built in the simulation software Adams,and the simulation scheme was developed by the orthogonal experimental design method,and then the simulation is performed.The simulation results were analyzed.After that,the influences of the orientation and size of the elliptical trajectory and the horizontal and vertical distance between the hip joint and the elliptical trajectory center on the joint angle were summarized.Finally,the prototype and the experiment of the elliptical trajectory adjustable lower limb rehabilitation robot were carried out.The parts were machined according to the drawings and assembled into a complete machine.Designed and conducted the test plan,collected the prototype test data,compare the prototype test data and the simulation test data to verify the correctness of the design.