A Novel Continuous Nonsingular Finite–Time Control for Underwater Robot Manipulators

In this paper, the tracking control problem of underwater robot manipulators is investigated under influence lumped disturbances, including unknown ocean current disturbances and parameter uncertainties. The proposed novel continuous nonsingular finite–time (CNFT) method twofold. Firstly, modified adaptive super–twisting algorithm (ASTA) with a fast terminal sliding mode (NFTSM) manifold to guarantee convergence both in phase reaching phase. Secondly, higher–order disturbance observer (HOSTDO) exploited attenuate effects disturbances. Considering time–varying gain matrix closed–loop system, bounded stability strictly proved via Lyapunov theory. Hence, superiority controller singularity–free, convergence, chattering–free, high steady–state performance, good robustness by resorting methods CNFT ASTA combination observer. Finally, numerical simulations are conducted on two degree–of–freedom (DOF) manipulator demonstrate effectiveness performance designed controller.