| In recent years,the incidence rate of stroke in China is on the rise.After stroke,patients are not only prone to language and perception disorders,but also prone to limb movement disorders(such as lower limb hemiplegia).Rehabilitation treatment can effectively promote the functional recovery of patients’ lower limbs,so as to improve their quality of life.However,at present,China’s rehabilitation treatment industry not only lacks a large number of professionals,but also has obvious defects in the traditional rehabilitation treatment method of "one-to-one" relying on physiotherapists and patients,mainly manifested in high training intensity,long treatment cycle and high treatment cost.Therefore,it is of great practical significance to develop a lower limb rehabilitation robot that can meet the personalized needs of different hemiplegic patients.At present,the problems existing in the research of lower limb rehabilitation robot at home and abroad mainly include the complex mechanical structure of exoskeleton and the inability to fine tune the leg length adjustment structure.This paper designs and studies the lower limb rehabilitation robot with two degrees of freedom.The specific research contents are as follows:Firstly,this paper puts forward the overall design idea of the two degree of freedom lower limb rehabilitation robot.Aiming at the problem that the leg length adjustment structure of the lower limb rehabilitation robot cannot be fine-tuned,a double guide shaft leg length adjustment structure is designed.In order to lighten the weight of exoskeleton lower limb rehabilitation robot,the exoskeleton structure is improved,including the re selection of driving device,the design of double guide shaft variable single hollow rod and the design of rod length based on linear programming.Secondly,the weight reduction system based on pulley block is designed in this paper.The weight reduction system sets three weight reduction modes(30%,50% and 70%),which can be set according to the actual situation of patients.The weight reduction system added spring elements,can reduce the impact of foot and ground to a certain extent,but also adapt to the change of the body’s center of gravity,automatic adjustment of the position of the body’s center of gravity.Aiming at the tedious problem of human-computer interaction force measurement,a human-computer interaction force measurement module based on tension and compression sensor is designed to detect the motion intention of patients.Thirdly,in this paper,a human gait experiment based on the dip sensor was carried out,and several groups of experimental data were obtained.A curve difference algorithm was proposed,and then the data were processed based on Bessel formula and La IDA criterion.The human gait trajectory was fitted in MATLAB,which solved the inconvenient problem of human gait trajectory measurement.Fourthly,in order to study the torque changes of hip and knee joints during human walking,the walking dynamics simulation of man-machine model under three weight reduction modes(30%,50% and 70%)is carried out in ADAMS,and the simulation results are analyzed.Finally,in order to track and control the human gait,the Lagrange dynamic equation of the man-machine leg double pendulum model is derived,and the PD control simulation based on model compensation is established in MATLAB.The simulation results show that the algorithm has fast response speed and small tracking error in trajectory tracking. |
