Dynamic Modeling And Simulation Of A Cable-driven Upper Limb Rehabilitation Robot

In recent years,the problem of the aging population in the world has gradually emerged,and the incidence of senile diseases has also increased,among which the incidence,disability,and mortality of stroke remain high.Patients who are disabled due to stroke mainly manifest as limb motor dysfunction.In clinical treatment,it often takes a lot of manpower,financial resources,and time to improve the patient’s limb function.Therefore,in response to this practical problem,scholars from various countries have launched a series of studies in order to replace traditional artificial rehabilitation training with upper limb rehabilitation robots.This paper summarizes the development process and current situation of the upper limb rehabilitation robot.The structure and movement characteristics of the human upper limb were analyzed.This paper introduces the rehabilitation treatment stage of the human upper limb and formulates the rehabilitation action track corresponding to the treatment stage.Combined with the above content,the structure of the cable-driven upper limb rehabilitation robot is designed.By using the advantages of the cable-drive,the motion inertia of the manipulator is minimized,and the shortcomings of the traditional motor-driven rehabilitation robot,such as lack of flexibility and excessive stiffness are improved.Based on the D-H coordinate method,the kinematics model of the cable-driven upper limb rehabilitation robot is established,and the forward and inverse kinematics analysis is completed.The correctness of the forward kinematics model is verified by MATLAB robot toolbox simulation,and then the relationship between the length of the cable and the joint angle is analyzed.Based on the three rehabilitation action trajectories,the change law of the cable length is analyzed.The dynamic model of the upper limb rehabilitation robot is established based on the Lagrangian equation.The trajectory in the joint space is planned within the angle range set by the interpolation method,and the trajectory is taken as an example to calculate the joint torque.Then,the dynamic simulation model is established in ADAMS,the reasonable simulation parameters are set,and the joint angle function is used to drive the joint motion.The simulation torque results are consistent with the theoretical calculation data,which verifies the correctness of the dynamic model Finally,the cable tension is analyzed and solved by the optimization method.The results of the cable tension meet the constraint conditions,and the tension changes smoothly.The experimental results show that the upper limb rehabilitation robot designed in this paper can meet the training needs of the example movement,has good application value,and lays a theoretical foundation for the subsequent cable selection.This research provides a new idea for the design of upper limb rehabilitation robots.The characteristics of the cable is used to make the training movement of the upper extremity rehabilitation robot have a certain degree of flexibility.At the same time,it also provides a new way to solve the similar problem of excessive motor drive rigidity.