Finite time trajectory tracking control of underwater salvage robot under full-state constraints

Aiming at the problem that the trajectory tracking of underwater salvage robots is subject to model uncertainty and complex unknown interference when working in the marine environment, a finite time trajectory tracking control scheme based on command filtering and full-state constraint is proposed. The scheme uses the super-twisting algorithm to design the observer to accurately estimate the composite disturbance composed of model uncertainty and unknown complex time-varying disturbance in the system. Secondly, the finite-time command filter based on the first-order Levant differentiator is introduced to solve the problem of ”differential explosion” in deriving the virtual control law concerning time. The barrier Lyapunov function, backstepping control method, and finite-time control theory are combined to achieve finite time full-state constraints. Then, the control scheme is verified by Lyapunov stability, which can make the position error and velocity error of the system converge to the stable region in a finite time.