Hybrid threshold event-triggered control for sail-assisted USV via the nonlinear modified LVS guidance. (15th May 2023)

• Record Type: Journal Article
• Authors: Zhang, Guoqing; Chang, Tengyu; Wang, Wenxin; Zhang, Weidong
• Is Part Of: Ocean engineering. Volume 276(2023)
• Publication Date: 2023-05-15
• Subjects: Path-following -- Sail-assisted USV -- LVS guidance -- Adaptive neural control -- Event-triggered control; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2023.114160
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: This paper presents an adaptive event-triggered control algorithm for sail-assisted unmanned surface vehicle (USV) under nonlinear modified logic virtual ship (LVS) guidance, which addresses the issues of communication load and input saturation constraint. In guidance module, the reference signal generated by LVS guidance is further processed by nonlinear modification rules. That can effectively remove the abrupt phenomenon of actuators. In the control module, a robust adaptive control technique for sail-assisted USV is proposed by fusing adaptive compensation technology and hybrid threshold event-triggered. Unnecessary transmission is reduced between controller and actuator by constructing hybrid threshold event-triggered mechanism. Different from most existing event-triggered mechanism with fixed threshold parameters, threshold parameters in hybrid threshold event-triggered are dynamically adjusted according to the demands of the controller. Furthermore, the compensation effect of sail on the dynamic mechanism is considered. Adaptive parameters of rudder and propeller are constructed to improve the robustness of the closed-loop system. Finally, the theoretical stability of the proposed method is proved by Lyapunov stability theorem, and the control performance is evaluated by simulation platform, which verifies that the scheme has reliable tracking accuracy under time-varying disturbances. Highlights: The nonlinear modified LVS principle is proposed to improve sail acting performance. The hybrid threshold parameter setting can obtain satisfactory resource efficiency. It can be effectively released the coupling effect of sail force on power mechanism. The triggered state variables are semi-globally uniform ultimate bounded stable.