Design and Dynamics Analysis of Auxiliary Motion Cable Drive Parallel Robot
Stroke patients with motor dysfunction caused by aging need auxiliary rehabilitation training with the help of rehabili-tation institutions.A four-cable-driven parallel robot mechanism is designed to assist the basic posture movement of patients with dyskinesia from lying position to standing position.The winch driven by motor is used to control the elongation and shortening of rope,and assist the human body to realize the movement of basic posture.The winding part of the winch is a steel wire rope,and the lower end of the steel wire rope is connected with a rubber rope,whichx is respectively pulled at the key nodes of assisting hu-man movement.Through analyzing the kinematics of the mechanism,the Jacobian matrix between the cable length and the posi-tion coordinates of the traction point is solved,and the human motion angle and angular velocity are planned in the process of rope traction to the sitting and standing position.Considering the elasticity of rubber rope,the system dynamics modeling is de-rived based on Lagrange dynamics,and the dynamic simulation is carried out by Simulink.The simulation results obtain the variation laws of rise and lie angle,angular velocity,knee flexion angle and angular velocity in the process of human body trac-tion.The PID control method of nonlinear feedforward compensation is applied to control the retraction and retraction length of the rope,so that the rope can safely and smoothly reach the desired trajectory and speed,ensure the comfort of the human body,and prove the stability of the control system by Lyapunov method.The effects of gravity compensation,variable stiffness of flexible cable and different mass parameters of human body on system dynamics are simulated.Through comparative analysis,it verifies that necessity of elastic rope as actuator and the effectiveness and stability of control law design.
Flexible Cable Parallel RobotKinematics AnalysisDynamics AnalysisMotion SimulationFeedfor-ward PID Control
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维普
