Kinematics analysis of lower limb rehabilitation robot based on D-H method

At present, rehabilitation robots usually work together with patients and train them to achieve therapeutic effects by assisting them to complete movement within a certain track. In this paper, it analyzes the average length and proportion of Chinese human lower limbs, as well as the range of extreme motion and comfortable motion of each joint of human lower limbs. Based on the error transfer matrix of rigid body connecting rod, the three-DOF lower limb rehabilitation robot human lower limb static pose error model and human/machine integration model are established. The D- H method was used to solve the kinematic function between the angle of each joint and the position of the end of human lower limbs. Theoretical analysis of the kinematics of human lower limbs is to calculate its inverse kinematics parameters. In the motion control of rehabilitation robots, the inverse kinematics is more important than the forward kinematics, which is the basis for rehabilitation robot to realize trajectory planning under the training mode of passive trajectory traction, as well as the basis for compliant control. Finally, a simulation model is established with Matlab software, and the simulation results show the feasibility and safety of the rehabilitation training process.