A Sliding Mode Control Algorithm of Improved Reaching Law in Lower Limb Exoskeleton System

Abstract

The lower limb exoskeleton system is widely used in real life and production, and the lower limb exoskeleton system designed in this paper is mainly aimed at the movement of people with lower limb movement difficulty.The control driven system adopts sliding mode controller to drive brushless DC motor. Based on the improvement of traditional reaching law sliding mode control algorithm, this paper designs an improved reaching law sliding mode controller with high control precision and good control quality. Experiment model simulation is analyzed in Matlab/Simulink software environment, and four tests compare the performance of system dynamic and steady-state in classical PID control, general reaching law sliding mode controller, and improved sliding mode controller algorithm. The results prove that improved reaching law sliding mode controller can promote response speed and control precision, and solve fluency, safety and comfort when a person wears lower limb exoskeleton equipment.