An indirect adaptive nonlinear teleoperation control based on operator-environment impedance identification

This paper presents a robust adaptive control strategy for nonlinear teleoperation systems. The controller is based on estimation of the impedance of human hand as well as that of the environment. The mentioned system is subjected to unmodeled dynamics, time-varying parameters and external force disturbances. The upper bound for the norm of disturbances and system uncertainties are not used in the presented control scheme. Furthermore, there is no constraint on the rate of changes and the amount of unknown parameters and perturbations. Given a robust adaptive control action and adaptation laws, the transparency and stability in teleoperation systems are mathematically proved using Lyapunov's direct method. Finally, simulation results obtained from a teleoperation system with two-link rotary robots are presented to show the effectiveness of the proposed control scheme.