A sliding mode and non-linear disturbance observer based bilateral control for telerehabilitation systems with flexible manipulators

Abstract

Aiming at achieving high flexibility and safety, telerehabilitation systems and telesurgery systems often use flexible manipulators in the telerehabilitation systems. However, due to the structure of the flexible manipulator, it has strong model uncertainties and nonlinearity in its dynamic model which causes the difficulty of the accurate control. In order to accomplish accurate trajectory tracking of telerehabilitations systems with flexible manipulators, a bilateral controller is introduced on the basis of the sliding mode control strategy and a non-linear disturbance observer. The non-linear disturbance observer is applied to estimate the model uncertainties and external disturbance of both the master and the slave flexible manipulators in the telerehabilitation system. The asymptotic stability is analyzed by the Lyapunov function. Numerical simulations are performed and results show efficiency and effectiveness of our method.