Researching On Control Method Of Lower-limb Power Assisted Robot

For control system of robot, control algorithm is a hot spot of research, because an appropriate control algorithm is very important to the robot's function. The paper designed two kinds of control algorithm according to the trait of the Lower-limb Power Assisted Robot, then compared which control algorithm is better for the robot by making simulation and experimentation.The main content of this paper is introducing the development of Lower-limb Power Assisted Robot and some usual control algorithm in robot control, for example:PID control, impedance control, force/position control, fuzzy control and robust control. Considering that the task object of the Lower-limb Power Assisted Robot is to help the older and the weaker walk independently, we design the overall planning of the robot and choose PD control and fuzzy PD control to be the control system of the robot.We make kinematic analysis and kinetic analysis for the Lower-limb Power Assisted Robot, and set up the kinematic equation and kinetic equation for it. Then we build the kinetic model of the Robot based on SimMechanics, and get the relation between driving torgue and joint angle and angular velocity of the robot by kinetic simulation.The paper designed the control model for the Lower-limb Power Assisted robot based on MATLAB/Simulink, use PD controller to control the track of the robot, then we make error analysis of position. We build the skeleton and muscle of lower limb and simulate the model of the Lower-limb Power Assistd Robot with load. So the model of the robot is closer to the actual instance.Fuzzy PD controller is designed based on fuzzy theory. In the same situation, use fuzzy PD controller to control the track of the Lower-limb Power Assisted Robot and make error analysis of position.Based on dSPACE, the Semi-Substantial Emulation Platform, we use PD controller and fuzzy PD controller to carry out the track control of the robot. And experiment is proved that the effect of the fuzzy PD controller for the robot is better than PD controller.