Structure Design And Modeling Analysis Of Lower Limb Rehabilitation Robot

At present,robot technology is gradually applied to the field of rehabilitation to assist patients in safe and effective rehabilitation training.The lower limb rehabilitation robot can drive the patient's disabled lower limbs for walking rehabilitation training and restore physical function.The traditional lower limb rehabilitation robots have problems such as imbalance of patients' bodies,cumbersome structure and single gait planning during training.On this basis,this paper designed a new multi-joint driven three-degree-of-freedom lower limb rehabilitation robot.Based on the study of the mechanism of human lower limb rehabilitation,the structural design requirements of the lower limb rehabilitation robot were proposed.Based on this,a three-dimensional model of lower limb rehabilitation robot with balance function was designed by Pro-Engineer.It mainly included system frame,treadmill,suspension weight reduction mechanism,four-bar support balance mechanism and exoskeleton mechanical leg mechanism.At the same time,the drive and sensor of each joint were selected.On this basis,ANSYS was used to optimize the topology of the lower limb rehabilitation robot.Static analysis of the optimized remodeled parts revealed that it met the strength requirements.The structure is optimal and the weight is the lightest,which solves the cumbersome problem of the traditional rehabilitation robot.The D-H coordinate system of the lower limb rehabilitation robot was established by robotics.The relationship between the joint angle and the end pose was obtained by forward and inverse kinematics analysis.The relationship between joint velocity and end velocity was obtained by a Jacobian matrix.Analyze the workspace according to the Monte Carlo method.Kinematics analysis was verified by MATLAB.The dynamic analysis of the lower limb rehabilitation robot model was carried out by the Lagrangian functional balance method.The moment equations for the hip,knee and ankle were obtained.Kinematics and dynamics analysis provided a theoretical basis for the motion control and gait generation of lower limb rehabilitation robots.A gait parameter test system was set up to collect the angle value of the joints of the lower limbs when the normal human body walked with time.The gait planning of the swing leg,hip and other joints was carried out by using the five-time spline interpolation method,so that the gait of the lower limb rehabilitation robot was more suitable for the normal human walking gait.The positional function of the lower limb rehabilitation robot in the advancing direction and vertical direction of the sagittal plane was fitted by MATLAB.The virtual prototype simulation of the lower limb rehabilitation robot was carried out using ADAMS.The joints were driven by the SPLINE function to obtain kinematics and dynamics simulation parameters and characteristics.In order to verify the rationality of the lower limb rehabilitation robot design,the lower limb rehabilitation training experiment was carried out.The results show that the lower limb rehabilitation robot designed in this paper can produce the joint rotation angle that fits the human gait.And the joint angular velocity curve is not mutated,which is basically consistent with the simulation results.This shows that the exercise is stable and effective,and can achieve the rehabilitation effect of the lower limbs.