Sliding mode control of a 5 dofs upper limb exoskeleton robot

Abstract

Recent advances in robotics have led to the development of exoskeleton robots that are becoming extensively used in the medical domain, to assist and help people suffering from physical impairments recover mobility. Most of existing controllers designed for position control of exoskeleton robots are linear which may not be suitable for exoskeleton robots having complex structures under heavy uncertainties. In this paper, a sliding mode controller (SMC) is designed for position control of a 5 degrees of freedom exoskeleton robot dedicated for upper limb rehabilitation. The proposed sliding mode controller will be compared to a proportional-integral-derivative (PID) controller in order to verify its control performance. Experiments will be conducted considering two cases, firstly when the exoskeleton robot is subject to its own weight then with supplementary loads added to the exoskeleton to imitate the human upper limb. Results are illustrated and discussed in this paper.