Research On Human-robot Coordination Control Of Lower Limb Exoskeleton Robot

The lower limb exoskeleton robot is an intelligent mechanical device worn outside the human body.It combines the knowledge of biomedicine,mechanical manufacturing principle,control theory and computer technology to form a complex intelligent system.Different from the traditional robot,it not only works as a machine,but also cooperates with human as a whole.By controlling the movement of the robot,it provides the wearer with pre-defined rehabilitation training,support,protection and other functions.In this paper,a rehabilitative exoskeleton robot is designed for the patients with lower extremity dyskinesia,including the design of its mechanical structure,the establishment of kinematics and dynamics model,and the research of man-robot coordinated control method.The effectiveness of the control scheme is verified by the virtual prototype joint control simulation.The main contents of this paper are as follows:The physiological structure and movement mechanism of human lower limbs were analyzed.This paper designs a mechanical structure of lower limb exoskeleton with degree of freedom fitting human normal walking law and easy to wear,and uses Solid Works to complete the establishment of its three-dimensional model.The kinematics and dynamics of exoskeleton are analyzed.The D-H method is used to establish the forward kinematics model of exoskeleton mechanism and analyze the influence of the change of exoskeleton robot joint angle on the posture the analytical method is used to establish the inverse kinematics model of exoskeleton mechanism and analyze the influence of the change of exoskeleton robot joint angle.The kinematics model is simulated and analyzed by MATLAB to verify its correctness.The dynamic model of exoskeleton mechanism is established by Lagrange method,and the relationship among joint torque,joint angle and angular velocity is analyzed.The dynamics model of exoskeleton mechanism is established by ADAMS software.The friction force,gravity force and human-robot interaction force are added to simulate and analyze the force of each joint.The correctness of the dynamics model of exoskeleton robot is verified,which lays a foundation for the research of human-robot coordination control.Several common robot control methods are analyzed and compared.Aiming at the shortcomings of the classical PID control strategy,such as the difficulty of parameter tuning and poor anti-interference ability,an improved PID control method based on fuzzy rules is reseached.Using fuzzy rules to adjust the parameters of PID controller in real time can enhance the robustness of the control system.A sliding mode control method is reseached for the multi input and multi output nonlinear complex control system of lower limb exoskeleton robot,which is insensitive to the changes and disturbances of robot system parameters and has good robustness.Adams and MATLAB / Simulink are used to simulate the joint control of virtual prototype,and the regulation ability,response speed and tracking effect of exoskeleton mechanism are analyzed in detail.The effectiveness of PID control scheme based on fuzzy rules and sliding mode control scheme is verified.