Research On Active Control Method Of Upper Limb Rehabilitation Robot

Hemiplegia is the most common sequelae of stroke.If rehabilitation is not performed in time,it is easy to cause muscle atrophy and other problems,which will bring great inconvenience to the patient’s daily life.At present,the clinical use of artificial assisted treatment methods has not only caused a shortage of medical resources,but also failed to measure the active participation of patients.This article takes the five-degree-of-freedom upper limb rehabilitation robot as the research object,mainly studying the realization of the actual movement trajectory of the robot end can accurately track the desired trajectory when the patient is undergoing active rehabilitation training,while maintaining a good flexibility control method between the robot and the patient,thereby improving the patient The effectiveness and safety of rehabilitation training.The main research contents of this paper are as follows:1)Basic theory of upper limb rehabilitation robot.The use of D-H method to analyze the robot movement process,describe the relationship between the robot end pose and each joint angle,compare and analyze the robot end movement information through theoretical calculation and virtual simulation;use Lagrangian method to describe the robot movement process.The torque of each joint is changed,and the relationship between the displacement and torque of each joint of the robot is verified.2)The method of planning the end motion trajectory of the rehabilitation robot.First,the limit position angle of the robot is determined according to the limit position angle of each joint motion of the human body,and then the working space of the robot is drawn by the Monte Carlo method;by comparing the two methods suitable for joint space trajectory planning,the five-order multiple formula is obtained.The conclusion that the interpolation is better;in the Cartesian space,the frequently used spatial straight-line interpolation method is used for simulation;the result proves that the trajectory of the robot is continuous and smooth,the speed is slow,and it is relatively stable,which is suitable for patients to perform rehabilitation exercises.3)Optim ization of active control method of rehabilitation robot.In order to improv e the position accuracy of the end of the robot during active training of patients and i mprove the flexibility with the robot,the impedance control method is optimized.When the fuzzy controller is looking for impedance control parameters,it solves the shortco ming of too much time-consuming in the traditional optimization method,but there is st ill the problem of low optimization control accuracy.Therefore,this paper takes the fuz zy amount and membership of the membership function in the fuzzy controller as the p arameters to be optimized in the genetic algorithm,and makes the copy,cross and varia tion operation to determine the optimal value of the new impedance control parameters.The simulation results show that when optimizing the impedance controller,compared with the fuzzy impedance method,the genetic fuzzy impedance method has higher accu racy and better flexibility between man and machine.Finally,two control methods,genetic fuzzy impedance and fuzzy impedance,were used to control the upper limb rehabilitation robot to drive the healthy subjects to carry out shoulder outreach,single-joint movement of elbow bending and multi-joint movement of shoulder and elbow bending together,according to the motion information obtained by various sensors,to depict the trajectory of the robot’s end movement.The experimental results show that the system using the genetic fuzzy impedance control method exhibits higher accuracy and good flexibility.