Dynamic event-triggered adaptive fuzzy command-filtered disturbance rejection tracking of vessels with saturated actuator dynamics

This paper presents a dynamic event-triggered adaptive fuzzy command-filtered disturbance rejection tracking for marine vessels with model uncertainties and harmonic ocean disturbances under saturated actuator dynamics. The adaptive internal model principle provides a promising approach for ensuring the disturbance rejection under saturated actuator dynamics. The parametric exogenous system describing ocean disturbances is converted into a canonical model with an unknown input vector. An internal model observer is constructed to provide an online state estimation to represent the disturbances with a parametric equation. An auxiliary system generates the filtered unachievable portions of system-state vectors induced by saturated actuator dynamics to correct the adaptive feedback errors online to address the actuator saturation effects. The dynamic event-triggered control, involving the additional internal dynamic variable, reduces the control execution frequencies to avoid actuators’ excessive wear and tear. The fuzzy logic systems approximate model uncertainties online. The adaptive fuzzy command-filtered backstepping method facilitates designing the tracking control law. A theoretical proof of achieving position and heading tracking and guaranteeing the control stability is derived. The efficacy of the theoretical results is demonstrated by performing simulations and comparisons on a marine vessel under various scenarios.