Steering model identification and control design of autonomous ship: a complete experimental study
TL;DR: In this article, a steering ship model is proposed for the study of autonomous ship manoeuverability and the design of ship motion control system, but it is always a difficult task to find the mathematical model by first finding the steering model.
Abstract: Steering ship models are important for the study of autonomous ship manoeuverability and design of ship motion control system. It is always a difficult task to find the mathematical model by first ...
Citations
More filters
TL;DR: In this article , the authors present a systematic review of Digital Twins on ships and propose the identification of weaknesses and correlations between current Digital Twins applications in the maritime industry and other industry fields, which may be repeated in future studies to provide a fair and objective overview of the research advancements in the topic.
7 citations
TL;DR: In this paper , a test platform for the intelligent navigation of the model ship is designed, and the authors test the effect of the optimal switching strategy of the motion controller on the performance of the ship.
Abstract: Fully autonomous navigation is the highest level of ship autonomy, which has high requirements for the adaptability of the ship control system. Taking navigation with large turning errors as an example, this paper combines the intelligent optimization controller with the traditional controller and adopts the controller switching strategy to guide the ship’s path following. In order to illustrate the feasibility of optimizing the switching mode of the motion controller to reduce the large turning error during ship navigation, this paper designs a test platform for the intelligent navigation of the model ship, and tests the effect of the optimal switching strategy of the controller. Firstly, the structure of the intelligent ship system is analyzed, and the framework of the intelligent navigation system is emphasized. Secondly, based on the analysis of the characteristics of controllers, the optimal switching strategy of the motion controller is proposed. Then, the construction process of the testing platform is described. Finally, the optimal switching strategy of the motion controller is verified on this test platform for the case of a large turning error of the ship. The results show that the implementation of the switching strategy can effectively reduce the control error compared with the mode without using the strategy. The experiment extends the ship motion control mode strategically and improves the adaptability of ship motion control. Based on the testing platform, this experiment can simulate the process of the control system autonomously selecting an appropriate controller according to the ship’s motion state and navigation scenarios, which is helpful to enhance the adaptability of the ship in the face of special navigation scenarios.
3 citations
21 Feb 2022
TL;DR: In this article , the performance of different controllers for the heading control and path following of a KVLCC2 tanker ship under wave disturbances is investigated and compared with a linear Model Predictive Controller (MPC).
Abstract: This work investigates the performance of different controllers for the heading control and path following of a KVLCC2 tanker ship under wave disturbances. The guidance law is designed based on the Line of Sight (LoS) algorithm. The Maneuvering Modeling Group (MMG) Model of the KVLCC tanker is used to represent the system dynamics, whose linearized model with usual assumptions doesn’t satisfy the straight line stability. An input-output based linear model is obtained by relating the rudder deflection to yaw rate using system identification method, and subsequently used for tuning the controllers. The tuned gains of the controller is then applied to the nonlinear model. The performances of PID and LQR are studied and compared with a linear Model Predictive Controller (MPC). The MPC outperforms the PID and LQR in the presence of external disturbances as well as under calm water conditions.
1 citations
References
More filters
TL;DR: It is argued that certain duties of patients counterbalance an otherwise unfair captivity of doctors as helpers and that vulnerability does not exclude obligation.
Abstract: There has been a shift from the general presumption that “doctor knows best” to a heightened respect for patient autonomy. Medical ethics remains one-sided, however. It tends (incorrectly) to interpret patient autonomy as mere participation in decisions, rather than a willingness to take the consequences. In this respect, medical ethics remains largely paternalistic, requiring doctors to protect patients from the consequences of their decisions. This is reflected in a one-sided account of duties in medical ethics. Medical ethics may exempt patients from obligations because they are the weaker or more vulnerable party in the doctor-patient relationship. We argue that vulnerability does not exclude obligation. We also look at others ways in which patients’ responsibilities flow from general ethics: for instance, from responsibilities to others and to the self, from duties of citizens, and from the responsibilities of those who solicit advice. Finally, we argue that certain duties of patients counterbalance an otherwise unfair captivity of doctors as helpers.
17,373 citations
08 Apr 2011
TL;DR: In this article, the authors present a survey of the latest tools for analysis and design of advanced guidance, navigation and control systems and present new material on underwater vehicles and surface vessels.
Abstract: The technology of hydrodynamic modeling and marine craft motion control systems has progressed greatly in recent years. This timely survey includes the latest tools for analysis and design of advanced guidance, navigation and control systems and presents new material on underwater vehicles and surface vessels. Each section presents numerous case studies and applications, providing a practical understanding of how model-based motion control systems are designed.
1,389 citations
"Steering model identification and c..." refers background or methods in this paper
...…coupled surge-sway-yaw representation that is adequate for portraying ship manoeuvring during the turning circle and zigzag tests can be derived as Fossen (2011). m[u̇− vr − xgr2 − yg ṙ] = X m[v̇+ ur − ygr2 + xg ṙ] = Y Izṙ +m[xg(v̇+ ur)− yg(u̇− vr)] = N] (1) Here m is the mass of the ship…...
[...]
...Traditionally, the ship dynamics are determined from first principles using Newtonian Mechanics (Fossen 2011)....
[...]
...…Proportional-Integral-Derivative (PID) control or linear quadratic regulator control or fuzzy control or nonlinear control can be easily designed and implemented not only for the scale model but also for the actual vessel itself (Fossen 2011), Brendon and Gary (1995) and Im and Seo (2010)....
[...]
TL;DR: The main line of argument supporting their introduction pertains to the increase in navigational safety, which is expected to be achieved by reducing the frequency of human-related accidents on board ships, by removing the crews.
209 citations
"Steering model identification and c..." refers background in this paper
...Presently, the focus of global research is in the area of developing unmanned autonomous merchant vessels such as cargo ships, container ships, etc. Wróbel et al. (2017)....
[...]
TL;DR: In this paper, a two-dimensional path following control system for autonomous marine surface vessels is presented, which is obtained through a way-point guidance scheme based on line-of-sight projection algorithm and the speed controller is achieved through state feedback linearization.
192 citations
"Steering model identification and c..." refers methods in this paper
...Based on the first-order Nomoto equation, the equation of motion describing the zigzag manoeuvre (Moreira et al. 2007; Clarke 2003) is:...
[...]
...Based on the first-order Nomoto equation, the equation of motion describing the zigzag manoeuvre (Moreira et al. 2007; Clarke 2003) is: TEṙ + r = Kd (11) Integrating both sides of (11) between limits ta and tb, we get:∫tb ta TEṙ dt+ ∫tb ta r dt = K ∫tb ta d dt (12) Rearranging (12) and…...
[...]
TL;DR: System identification techniques are applied to determine ship steering dynamics and parameters of a linear continuous time model are determined using discrete time measurements using the maximum likelihood method.
192 citations