Design And Analysis Of Auxiliary Motion Cable Driven Parallel Robot For Patients With Dyskinesia

Stroke patients are often accompanied by clinical symptoms such as language dysfunction,limb inflexibility and dyskinesia.Among them,patients with limb dyskinesia in the early stage of the disease can gradually recover through rehabilitation training.At present,the rehabilitation treatment methods for stroke patients with motor dysfunction can be roughly divided into traditional Chinese medicine acupuncture and moxibustion,phased training plan formulated by rehabilitation division,rehabilitation auxiliary robot and other methods to help patients recover motor function.However,due to the influence of management mode,schedule,treatment cycle and other factors,acupuncture therapists and rehabilitation teachers are difficult to ensure the intensity of long-term exercise training.Rehabilitation robots are mostly used to carry out targeted training or auxiliary gait training on the affected limbs in the later stage of rehabilitation.Due to the limited space and the applicability of rehabilitation function,the effect is not good for patients who are still in bed.In contrast,the flexible cable driven parallel robot has the advantages of large traction space and one-way force bearing of the rope.The rope raction of the human body is more friendly and safe.In addition,stroke rehabilitation theory shows that assisting patients to sit up,stand and other basic posture changes in the early stage after illness is the first step of rehabilitation training,which is of great significance.The main work is as follows:A 4-cable-driven parallel robot mechanism is designed to assist the movement of patients with dyskinesia in the basic posture from lying position to standing position,so as to ensure the safety of patients.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,which is respectively pulled at the key nodes of the auxiliary human body movement.The motor is used to drive the winch to control the rope elongation and shorten the auxiliary human body to realize the movement of the basic posture.The kinematics of the mechanism is analyzed,the Jacobian matrix between the cable length and the position coordinates of the traction point is solved,and the human motion angle and angular velocity in the process of the rope pulling the human body to the sitting and standing position are planned,and the rope velocity of the human body and the angular velocity of the human body in the lying and standing position are planned.In order to consider the dynamic influence of rubber rope elasticity,the system dynamic modeling is carried out based on Lagrange dynamics,and the dynamic simulation is carried out by Simulink to analyze the variation rules of rise and lie angle,angular velocity,knee flexion angle and angular velocity in the process of human body traction.Based on the system dynamics model,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,the necessity of elastic rope as actuator and the effectiveness and stability of control law design are verified.In this thesis,through the design and analysis of the flexible cable driven parallel robot for assisting patients with motion disorders,it provides ideas for the rehabilitation training of stroke patients in the early stage of using the flexible cable driven parallel robot.The feasibility and stability of the mechanism are verified through theoretical analysis and simulation.At the same time,the design of the control law ensures the universality of the control effect under the conditions of variable rope stiffness and variable human body mass parameters,It provides reference value for flexible cable driven parallel robot in feedforward compensation PID control method.