Research On Control Of Wire-driven Lower Limb Rehabilitation Robot Based On LabVIEW

In recent years, with the increasement of the number of patients with lower limb motor dysfunction, rehabilitation robots are more and more widely used in the field of lower limb rehabilitation. Wire-driven rehabilitation robot has a simple structure,high load capacity,large scope of work and a fast moving speed, and has a more and more useful value in the field of rehabilitation. Compared with the traditional limb rehabilitation therapy, the robot can effectively improve the effect of rehabilitation training, reduce the labor cost, and change the training method and rehabilitation strategy for different patient. The use of motion control card also improves the interaction and reliability of the robot. Therefore,research on the control of rehabilitation robot is of great significance of improving the performance of the robot.The main contents are as follows:Firstly, a lower limb flexion-adduction and abduction double-purpose robot structure is advanced according to the existing robot structures. The host computer uses industrial control computer and the slave machine drives the ropes with motors. LabVIEW, motion control card and data acquisition card are also used. Force, speed double closed loop control strategy is used to provide a better rehabilitation effect.Secondly,kinematic analysis and kinetic analysis are done to the rehabilitation robot.The kinematic analysis is based on the simplified lower limb model and the motor's rotation speed regulation in single gait cycle is calculated with the help of joint angle data of hip and knee and the geometry of the robot. The kinetic analysis calculates the torque and power with the fitting method. The output force of the robot is calculated by using the Lagrange method and the power method, and distributed to each wire according to the characteristics of different stage of the gait cycle. The joint trajectory, motor speed and tension of wire are simulated.Thirdly, the control system of the robot is studied. The robot is programmed by Lab VIEW to realize the functions. Different control method of the motor's speed changing motion provided by motion control card are analyzed and the most suitable motor speed changing program is gotten as a result. The tension data which is read by data acquisition card is used in the force control switch program, the force control speed changing program and the force feedback control program.Finally, experimental research is done to the prototype system. The parameters of the driver is set and the cable sensor is calibrated. Meanwhile, the programs written with LabVIEW are tested to verify the effectiveness and the feasibility.