Sliding Mode Control For Lower Limb Rehabilitation Exoskeleton Contacting With Floor

In this study, a lower limb rehabilitation exoskeleton (LLRE) contacting with floor with uncertainties and parameter variations has been controlled using a sliding mode controller (SMC). The dynamic equations for the lower limb rehabilitation exoskeleton in case of contacting with floor in reduced order form have been derived using augmented Lagrange equations which include Lagrange multiplier and corresponding Jacobian vectors. A comparative study has been achieved between two controllers: sliding mode controller and computed torque controller. Simulation results indicate the superiority of SMC controllers over the CTC in terms of tracking error and robustness toward the uncertainties and external disturbances.