Research On Horizontal Lower Limbs Rehabilitation Robot

With the improvement of people's living standards and the changes in diet in recent years, cerebrovascular diseases have become frequently-occurring diseases in most countries in the world. The disease's incidence significantly increased and has younger trend. This disease has been recognized as one of main diseases that endanger the life at present. After the patients with cerebrovascular disease were in stable disease stage, injured nerve shall recover gradually. But recovery process is very slow and the nerve can't recover entirely. Neurologist and rehabilitation doctor find that the function of injured nerve system can recombine and compensate, lost motion function can recover and the self-care ability of patient shall improve by rehabilitation training in long clinical practice. Rehabilitation training robot is a kind of assistant rehabilitation therapy automatic equipment that can assist patient with lower limbs motion dysfunction in completing clinical rehabilitation training content, and can provide feedback information for patient and doctor. Compared with traditional treatment method, robot assistant treatment method can guarantee training intensity and rehabilitation efficiency. The rehabilitation process and effect also are evaluated objectively. Hence, people pay more attention to rehabilitation robot that has application prospect in rehabilitation project and medicine.This work is supported by National Natural Science Foundation of China. The project is called key technologies for lower limbs rehabilitation training robot (60575053). According to how to rehabilitate lower limbs motion function of patient that has lower limbs motion dysfunction caused by cerebrovascular disease using lower limbs rehabilitation robot, theoretical analysis and experimental research of man-machine system's rehabilitation motion planning, lower limbs mechanics characteristic analysis, and rehabilitation strategy are made.Research status of horizontal lower limbs rehabilitation robot and related fields is presented at home and abroad. Based on lower analyzing and comparing limbs rehabilitation robot's machine, working principle and control strategy at home and abroad, the machine scheme of novel horizontal lower limbs rehabilitation robot is proposed and the robot's control scheme is designed. This robot is suitable for patient with different statures and weights. The required training mode is chosed according to the different purposes in different rehabilitation phase.Forward and inverse kinematics of horizontal lower limbs rehabilitation robot's man-machine system is analyzed. Work range of robotic system is determined. The forward and inverse kinematics model is verified by MATLAB/SimMechanics software. The results show that the model is correctness. Aiming to rehabilitation training in different rehabilitation phases, rehabilitation training of lower limb joint is planned and the motion planning of rehabilitation robot is obtained based on Kinematics model of man-machine system. Thus all the work above has made the basis for rehabilitating natural walk motion.Lower limb's dynamic model, robot dynamic model and man-machine dynamic model are established respectively using Lagrange method and Newton-Euler method. The spring coefficient and damping coefficient of human body dynamic model are analyzed using experiment research. The rehabilitation train of lower limbs is also simulated. Thus the dynamics parameters of man-machine system are obtained. These parameters are not only used for evaluating security and comfort of patient as rehabilitation training according to the data of human biomechanics, but also provide the theory basis for designing control system.Active-passive control strategies and power-assisted control strategies are chose according to the rehabilitation curing process of cerebrovascular patients. To achieve the passive training, active training and active-passive training in clinical training, the position control, impedance control and fuzzy impedance control are used. Power training mode is achieved using current loop control. These control strategies are simulated based on simulation model in MATLAB/Simulink software. The results show that all control strategies are feasible and effective. Thus all the work above has provided the theory basis for the experiment research.The experiment prototype of horizontal lower limbs rehabilitation robot is designed. Measuring system and control system of the robot are introduced. Lower limbs rehabilitation train experiments are completed using dSPACE platform. These experiments include passive training experiment, power-assisted training experiment, active training experiment, the experiment of simulating spasm and active-passive experiment of lower limbs. The results show that the robot's machine is rationality, and the all control strategies presented in control system is effective.