Design and simulation of PID controller for lower limb exoskeleton robot

Abstract

Lower limb exoskeleton robot is a robot that functions as a walking tool of movement for the lower of the human body (usually made for patients with stroke and paraplegic). However, as time goes by lower limb exoskeleton robot is no longer reserved for patients with stroke and paraplegic, some of them are made to military requirements or the need to lift heavy stuff. In this case, the lower limb exoskeleton robot is used for rehabilitation aids for people with paraplegic who suffered an accident on the lower part of the human body (lower limb). This paper presents the design and simulation of the lower limb exoskeleton robot using CAD software to design, and Matlab/Simulink for simulation. The first step after the design of the lower limb exoskeleton robot is completed, we export the file of robot design to the SimMechanics (using first generation). After we obtain the results of the export file, we give a Proportional-Integral-Derivative (PID) controller at each revolute joint. Then, we use a Matlab/Simulink to analyze the response system of PID controller. For the stability analysis of controller, we plot the transfer function of system into the root locus method. Based on the results of simulation, the PID controller has been able to making each revolute joint of the lower limb exoskeleton robot to become stable.