Adaptive Event-Triggered Fuzzy State Observer Control for Surface-Air Vehicles Subject to the Harbor-Approaching Operation

Abstract

This paper is concerned with an adaptive fuzzy observer control algorithm for the sea-air cooperative system subject to the harbor-approaching operation. The proposed algorithm consists of the guidance and control. In the former, a time-varying velocity function with the exponential form is conceived for achieving desired velocity-changing navigation effect. In the control part, a novel event-triggered fuzzy state observer is designed that uses the fuzzy logic system (FLS) and event-triggered mechanism, which is with two features. That is, the unmeasured variables of the underactuated surface vehicle (USV) and the unmanned aerial vehicle (UAV) are estimated, thereby mitigating the instability effect caused by external noise. Another feature is that the fuzzy triggered gain mechanism, using an adapting indeterminate threshold parameter, is designed to address the explicit problem of event-triggered amplitude gain. Furthermore, Lyapunov-based stability analysis provides a strictly theoretical guarantee with the semi-global uniformly ultimately bounded (SGUUB) stable. Finally, the effectiveness and advantages of the proposed strategy are verified through numerical results.