Research On Active And Compliant Control Of Lower Limbs Rehabilitation Robot Based On Motion Analysis

In recent years,as the aging of the population continues to increase,the number of the elderly patients with chronic diseases increase rapidly,especially cerebrovascular diseases stroke have become one of the major diseases of human life.The neurological damage caused by stroke can cause serious motor dysfunction if left untreated in time.The existing medical resources and rehabilitation facilities are in short supply,and rehabilitation physicians are under great pressure of work.The rehabilitation robot can replace rehabilitation physician to accomplish the limb assisted movement,which reduces the burden of the rehabilitation physician and ensures the intensities and efficiency of rehabilitation.However,most of the existing rehabilitation robots adopt passive training methods.The technology of active rehabilitation training is not perfect for rehabilitation.In the active rehabilitation training,the analysis of human motion and the compliant control is the key to achieve human-robot interaction control.Therefore,how to realize the real time and accurate analysis of human motion and the active compliance control of the rehabilitation robot have become the two major problems to be solved in the active training of the rehabilitation robot.The main work of this paper is as follows:Firstly,the structure of the horizontal lower limb rehabilitation robot is simplified.The positive and inverse kinematics model of the human-robot system is established.The lower limb dynamics model was established based on the regression equation of human'body parameters and the simplified model theory.This paper establishes the dynamic model of human-robot system in the active training modes after analyzing the characteristics of the human-robot interactionctiion in the training mode.These work lay the foundation for the active and compliant control of human-robot system.Secondly,a new analytical method of lower limb motion is proposed to generate the desired track synchronization with the movement intentions based on the mechanism and characteristics of surface Electromyography(sEMG).The coherence analysis is introduced to describe the coupling relationship between sEMG and joint quantitatively,and then the muscle channels can be selected.The Electromechanical Delay(EMD)between sEMG and joint Angle can be compensated with a first-order recursive filter.The algorithm of least squares limit learning machine based on golden section is proposed to shorten the training and prediction time.Finally,the effectiveness of the proposed method is verified by doing experiments.Thirdly,in order to make the process of the rehabilitation robot controlled more natural and comfortable in active rehabilitation training,the active and compliant control method is proposed with adaptive impedance control model.The nonlinear function of sEMG and impedance coefficient is created.And the adaptive impedance control model is established based on sEMG and human-robot interaction force to adjust the desired trajectory and then generates the target reference trajectory.The sliding mode iterative learning controller is proposed to suppress the repetitive interference and abnormal disturbance and achieves the stable tracking of the target trajectory.Finally,the control simulation model is established with matlab/simulink,and the proposed control method is simulated and verified.The results prove the feasibility and effectiveness of the method proposed.Finally,the experimental platform is established to control the horizontal lower limb rehabilitation robot in active and compliant including the signals acquisition system,the lower limb motion analysis system and the lower limb rehabilitation robot control system.The active and compliant control method based on motion analysis proposed in this paper is applied to the experimental platform to verify the effectiveness of the method.