Abstract
This paper presents a novel robust control strategy for path following of an unmanned surface vehicle (USV) suffering from unknown dynamics and rudder saturation. The trajectory linearization control (TLC) method augmented by the neural network, linear extended state observer (LESO), and auxiliary system is used as the main control framework. The salient features of the presented strategy are as follows: in the guidance loop, a fuzzy predictor line-of-sight (FPLOS) guidance law is proposed to ensure that the USV effectively follows the given path, where the fuzzy method is introduced to adjust lookahead distance online, and thereby achieving convergence performance; in the control loop, we develop a practical robust path following controller based on enhanced TLC, in which the neural network and LESO are adopted to handle unmodeled dynamics and external disturbances, respectively. Meanwhile, a nonlinear tracking differentiator (NTD) is constructed to achieve satisfactory differential and filter performance. Then, the auxiliary system is incorporated into the controller design to handle rudder saturation. Using Lyapunov stability theory, the entire system is ensured to be uniformly ultimately bounded (UUB). Simulation comparisons illustrate the effectiveness and superiority of the proposed strategy.
Highlights
In recent years, unmanned surface vehicles (USV) have received significant attention, due to their broad applications in the marine environment, such as ocean surveillance, gas exploration, and marine transportation [1,2,3]
Using the dynamic surface control (DSC) method, a practical path following control scheme was developed for underactuated ships in [8], whose advantage was that it could deal with the practical condition
Only needs one parameter to be adjusted. Both unknown dynamics and disturbances can be estimated by constructing a neural network and linear extended state observer (LESO), respectively, and the rudder saturation is effectively resolved by using an auxiliary system
Summary
In recent years, unmanned surface vehicles (USV) have received significant attention, due to their broad applications in the marine environment, such as ocean surveillance, gas exploration, and marine transportation [1,2,3]. In [15], a novel guidance control method was presented for a marine surface vehicle (MSV), in which the unknown sideslip angle was estimated using a reduced-order. In [26], a path following controller was presented for a surface vessel, in which the auxiliary system developed could cope very well with input saturation without any downtime. Motivated by the above observations, considering unknown dynamics, disturbances, and rudder saturation, this article presents a novel path following control strategy for the USV. Compared with traditional TLC, the enhanced TLC only needs one parameter to be adjusted Both unknown dynamics and disturbances can be estimated by constructing a neural network and LESO, respectively, and the rudder saturation is effectively resolved by using an auxiliary system.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
