In this paper, the path following control scheme of a fully actuated marine surface vessel under the condition of model uncertainties and unmeasurable states is developed. Firstly, an adaptive fuzzy state observer is designed to estimate the unmeasurable states of the vessel. To guarantee the robustness of the system, a kind of sliding mode intermediate variable with the improved approaching law is constructed to eliminate the chattering effect and the vessel can obtain a better control performance. By combining with the relative threshold event-triggered strategy, the controllers only update when the triggering conditions are met. Hence, the update frequency of controllers and the loss of actuators are enormously decreased in contrast with the fixed threshold event-triggered control law. Theoretical analysis proves that the tracking error can converge into a compact set, meanwhile the Zeno behavior is avoided. Simulation results and comparative analysis indicate the availability and superiority of the designed controllers.

本文提出了在模型不确定性和不可测状态下全驱动水面舰艇的路径跟踪控制方案。首先，设计了一种自适应模糊状态观测器，以估计船舶的不可测量状态。为了保证系统的鲁棒性，构造了一种具有改进的趋近律的滑模中间变量，消除了抖振效应，使船舶获得了较好的控制性能。通过与相对阈值事件触发策略相结合，控制器仅在满足触发条件时进行更新。因此，与固定阈值事件触发的控制律相比，控制器的更新频率和致动器的损耗大大降低了。理论分析证明，跟踪误差可以收敛到一个紧凑集合中，同时避免了芝诺行为。仿真结果和比较分析表明所设计控制器的可用性和优越性。