Event-driven prescribed performance distributed formation control for MSVs based on second-order step response with actuator input saturation.

This study aims to investigate the problem of event-driven distributed formation control for marine surface vehicles (MSVs) system, including prescribed performance constraint and actuator input saturation. By constructing a novel prescribed performance function based on second-order step response, the intuitive physical significance is realized, and the performance specifications imposed on the output tracking errors are achieved. Subsequently, a double-layer adaptive sliding-mode disturbance observer (ASMDO) is presented to compensate for lumped uncertain terms. Within the controller design stage, an auxiliary dynamic system is built to introduce the auxiliary intermediate control law, thus avoiding the need to directly design anti-saturation generalized control input for the MSVs system. Then, by incorporating external dynamic variable, a dynamic event-triggered mechanism (DETM) is proposed to regulate the transmission between the controller and actuators. Under the DETM, the designed controller only transmits the control force and torque into actuators at the specified triggering moment, and the trigger moment is independent of the internal state of the system. After that, the minimum inter-event time (MIET) of the proposed DETM is proved to be strictly positive, which ensures Zeno-free behavior. Lastly, the efficiency and advantages of the proposed event-driven distributed formation controller are verified through numerical simulations. • 1)In contrast to the existing performance function in (Lai et al., 2023 ; Wang et al., 2021c), the performance function proposed in this paper can ensure that the system response has a minimal system overshoot, which reduces unnecessary actuator actions. Furthermore, unlike the error transformation function in (Lai et al., 2023), the error transformation function in this paper can guarantee the control input amplitude is reduced in the initial stage. • 2)Different from the existing nonlinear disturbance observer (Dai et al., 2022), the ASMDO has the finite-time convergence property due to the application of fractional power. Subsequently, the lumped uncertainties are accurately estimated with minimal oscillation during sliding motion. In addition, the auxiliary intermediate control law is designed by introducing the auxiliary dynamic system, thus avoiding the need to directly design an anti-saturation generalized force for the MSVs system. • 3)In accordance with (Zhou et al., 2022), we present the DETM framework, which is designed to be independent of measurement errors that are related to control input. In other words, the triggering moment and inter-event time for the MSVs system are only associated with the evolution of the external dynamic variables. Combined with DETM, the proposed control scheme enables the controller to discretely transmit the control force and torque into actuators. Therefore, this allows for more efficient signal transmission management and reduces unnecessary actuator action. [ABSTRACT FROM AUTHOR]