Fault-tolerant control design for nonlinear multilateral teleoperation system with unreliable communication channels and actuator constraints

For nonlinear multilateral teleoperation systems, unreliable communication channels and actuator constraints are the main challenging issues to achieve the stability condition and satisfy the required performance. In this paper, a novel fault-tolerant control algorithm is proposed for a class of multi-degree-of-freedom nonlinear multilateral teleoperation systems with the aforementioned problems and unknown environmental forces. The time-varying delays and packet dropouts are incorporated in the unreliable communication channels, and the considered systems are modeled as a kind of T-S fuzzy systems with multiple time-varying delays. For actuator constraints, both the actuator failures and the unknown control directions are investigated in such research, by designing a novel fault-tolerant control scheme, the failures and control directions can be estimated simultaneously. Next, the radial basis function neural network (RBFNN) is introduced to estimate the unknown environmental force, and the estimated results are incorporated in the controller design and the mean-square stability of the closed-loop system with disturbance attenuation level is guaranteed. Finally, a numerical simulation example is given to show the effectiveness of the proposed method.