Adaptive Robust Control of Networked Multi-Manipulators with Time-Varying Delays

In this paper, an adaptive non-singular terminal sliding mode (NTSM) method is proposed for a networked multi-manipulator system. This paper aims at dealing with multiple challenging control problems. Firstly, a robust and adaptive controller is proposed to deal with random time-varying network delays in the existence of the parametric uncertainties in system dynamics, unknown frictions, and external disturbances. Secondly, the bounds of the uncertainties, frictions, and disturbances are not required as a prior by the robust adaptive control algorithm, while three compensatory bounds are calculated in real-time to compensate the errors introduced by the network delays and the acceleration estimation. Thirdly, for the network with the weak connectedness and unknown time-varying delays, the followers are able to synchronize to a time-varying leader trajectory. Numerical simulation results of a team of two degree-of-freedom (DOF) manipulators show that the designed control system ensures the good synchronizing performance with small and bounded tracking errors.