Saturation-Tolerant Tunnel Prescribed Control for Vessel-Train Formation of Underactuated MSVs

The vessel-train formation composed of multiple marine surface vehicles (MSVs) is an economical and feasible mode to improve the effectiveness of waterborne transportation. This paper investigates the performance-prescribed vessel-train formation of path-guided underactuated MSVs subject to unknown kinetics, input saturation, and actuator faults. We develop a saturation-tolerant prescribed control method for implementing the vessel-train formation along a parameterized path. Specifically, at the kinematic level, a saturation-tolerant prescribed performance (SPP) function is constructed by introducing non-negative modified variables to not only restrict tracking errors but also avoid possible violations because of input saturation and actuator faults. Then, the surge and yaw tunnel guidance laws based on the transformed errors are derived to achieve position and heading tracking under SPP constraints. At the kinetic level, the saturation-tolerant control laws are designed using the identified kinetics from echo state network-based estimators. By the Lyapunov stability analysis, all error signals of the proposed closed-loop system are proven to be uniformly ultimately bounded and evolve within SPP constraints against input saturation and actuator faults. Finally, simulation results are conducted to illustrate the effectiveness of the proposed saturation-tolerant tunnel prescribed control method for vessel-train formation.