To resolve the severe wear problems of steering engine and fin stabilizer, the nonlinear response characteristics of steering engine and fin stabilizer are studied by analyzing sea trial data of ship Yukun. The nonlinear response characteristics are summarized and applied to a rudder and fin hybrid control system. Decoupling, \(\hbox {H}_\infty\) and \({\rm H}_2\) controllers are designed to achieve

To ensure that the unmanned underwater vehicles (UUVs) can still successfully complete the corresponding tasks in the case of thrusters having faults, a novel fault-tolerant control strategy which combines the model predictive control (MPC) algorithm and the fault-tolerant reconstruction algorithm is presented in this paper. Firstly, a cascade control method based on model predictive control algorithm

Recently, the great enlargement of container ships has brought broad concern on the effect of whipping response. Meanwhile, the accompanying wider width of double bottom may cause more flexible responses of the double bottom structures. The numerical simulation studies have shown that the longitudinal stresses of the hold central bottom of a container ship due to the double bottom bending superimpose

How to calculate the 3D time-domain Green function and its gradients accurately and efficiently is the key to solving the hydrodynamic problem of ships. In this paper, the least square support vector machine (LS-SVM) theory was proposed for the first time to solve the ordinary differential equations (ODEs) satisfied by the time-domain Green function and the spatial derivatives in time domain. Furthermore

Propeller is the main device in marine vehicle to generate propulsive energy. During practical manoeuvring condition, it losses a major part of energy due to the formation of hub as well as tip vortex. This fact becomes a great concern for researcher and motivates to find some alternate energy saving device (ESD). In this paper numerical investigations, based on Reynolds Average Navier Stokes (RANS)

Currently, accelerated research on automation is involved in most fields associated with vehicle manufacturing. In the area of autonomous operation of marine vehicles, automatic berthing remains a problem due to the nonlinearity of the low-speed maneuvering model, poor control of the vessel at low speed, and collision with berth danger. A previous study on off-line automatic berthing reveals frequent

The prevention of excessive roll acceleration is one of the fundamental requirements of an oceangoing vessel at sea. In this paper, aiming at this requirement, we propose a new theoretical method for calculating roll angular acceleration, called “PDF line integral method.”. This paper presents the derivation of this method and a numerical comparison with Monte Carlo simulation (MCS) results; also,

Shipyard hoisting process is a project type manufacturing process which entails more sophisticated elements and relationships than other kinds of processes, this feature brings particular challenges when constructing a structured description of the process, called enterprise model, to introduce various Computer Integrated Manufacturing (CIM) technologies. However, most of the modelling methods devised

The Marine Environmental Committee (MEC) ocean model was applied to Onagawa Bay to examine the bay-scale water circulation and to evaluate the current configuration of aquaculture facilities that were devastated by the 2011 Tohoku earthquake. In this study, the drag forces of aquaculture facilities and the blocking effects of both stocked fish and shellfish were integrated to MEC ocean model. The model

Predicting the wave-induced response in the near-future is of importance to ensure safety of ships. To achieve this target, a possible method for deterministic and conditional prediction of future responses utilizing measured data from the most recent past has been developed. Herein, accurate derivation of the autocorrelation function (ACF) is required. In this study, a new approach for deriving ACFs

In this study, different operation factors affecting a ship’s wave statistics are studied, such as the slow steaming and voyage optimizations. Especially, the impact of various voyage optimization methods on the long-term wave statistics and corresponding fatigue damage during ship operations is investigated by comparing the encountered waves with the design wave scatter diagram. Three years of full-scale

The accuracy of underwater acoustic positioning is greatly influenced by both systematic error and gross error. Aiming at these problems, the paper proposes a robust zero-difference Kalman filter based on the random walk model and the equivalent gain matrix. The proposed algorithm takes systematic error as a random walk process, and estimates it together with the position parameters by using zero-difference

In the study of the cross-flow vortex-induced vibration of the cylinder, it is found that with the increase in the Reynolds number, the upper branch of the vibration amplitude and the lock-in region show an increasing trend. Currently, there are relatively few studies on two-degree-of-freedom VIV at high Reynolds number. In this paper, the Launder and Sharma low Reynolds number k–ɛ turbulence model

Conventional dynamic positioning (DP) systems on larger ships compensate primarily for slowly time-varying environmental forces. In doing so, they use wave filtering to prevent the DP from compensating for the first-order wave motions. This reduces wear and tear of the thruster and machinery systems. In the case of smaller autonomous vessels, the oscillatory motion of the vessel in waves may be more

This paper proposes a mathematical model for intermodal chains with seaborne transport, in which the optimization of a multi-objective model enables conflicting objectives to be handled simultaneously. Through the assessment of ‘door-to-door’ transport in terms of costs, time, and environmental impact, the most suitable maritime route and the optimized fleet are jointly proposed to maximize the opportunities

As the global warming, the Arctic Shipping Routes are gradually opened. The icebreakers are still in need to ensure the safe navigation of ships. During the voyage from East Asia to North-western Europe, the icebreaker will experience a long-distance voyage where over 60% of the distance is open water. As the bow of the icebreaker is full and the length-beam ratio is relatively high, it is quite important

Although many in-service welded built-up structures, which contain many welded joints as fatigue crack initiation sites, are subjected to many types of loading, their structural integrities are evaluated according to design codes based on theoretical and experimental investigations under uniaxial loading conditions. Additionally, most of these codes implement the S–N curves approach. This study highlights

An opposing sea was generated in an experimental wave basin. Here, an opposing sea is defined as a sea in which the wave spectrum has two peaks that are separated almost 180° in direction. Such an opposing sea can be observed, for example, when wind waves coexist in the opposite direction with swells. The opposing sea generation is based on an actual sea spectrum hindcast by a third-generation wave

Many-objective optimization refers to the optimization aiming at four or more objectives. More complex than multi-objective optimization, which copes with two or three objectives, many-objective optimization represents a challenging problem due to the complex trade-off relationships among the optimization objectives. In this study, a four-objective optimization system was proposed for reducing the

Autonomous navigation of ships is actively discussed nowadays. It is essential to recognize the surrounding conditions using radars and acquire position information using GPS. However, each of these existing sensors has its own problems. In order to achieve safer autonomous navigation in scenes such as automatic berthing, passing in a narrow line and closing to other ships, an imaging system that integrates

The importance of the uncertainty quantification in ship maneuverability prediction is expounded. An efficient method for the uncertainty quantification problem, the Non-Intrusive Polynomial Chaos (NIPC) method, is introduced. A 3-DOF MMG model is adopted to carry out simulations of 35° turning circle tests and 10°/10° zig-zag tests for a KCS container ship model. The effects of the uncertainty of

This paper aims to verify a new automatic berthing system using a path following algorithm. Berthing operation is one of the most burdensome tasks for crews among several ship operations. The maneuverability of a ship at low speed during berthing operation deteriorates and becomes more vulnerable to disturbances such as wind. Therefore, it is necessary to support and automate operations that require

The fatigue strength of a drill pipe is a critical factor governing the performance of drillings. Substantial research has been conducted related to fatigue evaluation and various factors that have an effect on fatigue. However, earlier studies have expressed concerns over the use of fatigue curves obtained from full scale tests and stress responses obtained via finite element analysis for evaluation:

This paper presents an automatic collision avoidance algorithm for ships using a deep reinforcement learning (DRL) in continuous action spaces. Obstacle zone by target (OZT) is used to compute an area where a collision will happen in the future based on dynamic information of ships. Agents of DRL detects the approach of multiple ships using a virtual sensor called the grid sensor. Agents learned collision

In this study, the information survey on water depth, currents, buoy drifting of the sea areas around Kinmen was completed from May 19 to May 26, 2019 (during southwest monsoon) and September 1 to September 8, 2019 (during northeast monsoon), and the marine waste drifting simulation model was established. Stony Brook POM with parallel computing is used as the model to simulate the drifting of marine

In the early 2000s, shipyards in South Korea were the most competitive in the world for commercial vessels because of their accumulated production and quality management capabilities. In the mid-2000s, the rising trend of international oil prices and predicted market growth of offshore structures caused large shipyards in South Korea to start focusing on the construction of offshore structures. However

Various industries are undergoing transformation given recently available pervasive sensors, low-cost and low-latency digital communication, and distributed control technologies. The objective of this paper is to support the introduction of Internet of things (IoT) technologies in the maritime industry. The maritime industry is analyzed as a system of systems to define performance criteria and functions

Springing and whipping play an important role in determining the fatigue damages of ultra-large container ships in waves, and it is widely acknowledged that the separation of the contributions of springing and whipping on fatigue damages is difficult. In this paper, the effects of springing and whipping on a targeted 21,000 TEU container ship are numerically investigated. The springing responses are

The aim of this paper is to develop a software, namely HPS-MOP, based on the multi-level and multi-point hydrodynamic optimization of hull-propeller systems during early-stage ship design. An efficient multi-objective evolutionary algorithm is used as the optimization technique to minimize the effective power and maximize the propulsive efficiency with considering some design constraints. Michell’s

A model predictive control (MPC) method with linear extended state observer (LESO) is presented to address the problems of the input constraints, uncertain parameters and external disturbances for path following of under-actuated surface ships without velocity measurements. The line of sight (LOS) guidance algorithm is employed to convert the path following into the heading control flexibly. The proper

The path-following control problem of an unmanned surface vehicle (USV) with unknown dynamics and unmeasured velocities is addressed in this paper. Main contributions are summarized as below: (1) considering that vehicle velocities are unmeasured directly, a finite-time velocity observer (FVO) is designed by utilizing available position information, which contributes to the path-following control and

This paper demonstrates the effectiveness of using global optimal rudder control with the covariance matrix adaptation evolution strategy, applied to a surge-sway-yaw-roll coupled numerical model, in preventing broaching-to, occurring under conventional PD rudder controls in stern quartering waves. In particular, the PD control with optimized PD parameters is more efficient than the time history-optimized

In this paper, an approach is proposed for the estimation of hydrodynamic coefficients variation as functions of Reynolds number. The variation of rotary damping linear hydrodynamic coefficients for off-design velocities is studied by simulating the rotating arm test and using computational fluid dynamics. Numerical results are validated by comparison with experimental ones reported in the literature

Although natural gas is documented as a low-emission fuel compared to the other traditional fossil fuels in internal combustion engines, recent research indicates large amounts of methane emission released by lean burn gas engines and highlights the importance of this emission on global warming. This paper aims at illustrating the main sources of unburned fuel in internal combustion engines with an

This paper presents a robust adaptive nonlinear feedback algorithm based on error-driven function for ships course-keeping which are subjected to the unknown time-varying disturbances, uncertain ship model parameters and control saturation. Nonlinear feedback and adaptive techniques are used to design the control law. The error-driven function is designed to avoid the input saturation and adjust the

Recent demands for large vessels and deep water exploration have increased the requirements for thicker plates to ensure the sufficient strength of such structures. The use of thicker plates, however, has an adverse influence on the fatigue performance. To enhance the fatigue life, post-weld treatments, such as weld-toe grinding, TIG (tungsten inert gas) dressing, hammer peening, and high-frequency

In this paper, statistics of ice thickness and ice strength of first-year sea ice along the Northern Sea Route (NSR) is studied to provide useful information for the design and operation of Arctic ships. Specifically, ice thickness, ice strength and other physical parameters of the sea ice are estimated. Four representative sites are selected to study the ice environment and ice strength in different

Biological fouling is undesirable accumulation of various organisms on submerged artificial surfaces. Combating biological fouling on watercrafts and immersed infrastructures is an eternal pursuit since ancient times. Traditionally, toxins, such as arsenic, mercury and tributyltin, were used as antifoulants on ship hulls but they are very harmful to both human and environment. Therefore, worldwide

A simulation verification of the hybrid propulsion ship considering accurate electro-dynamic model is required to evaluate ship maneuverability before the maritime demonstration. This paper presents the simplified model constructions for the hybrid propulsion ship using a real time simulator in terms of the dynamic models accuracy and the improvement of a computation speed. In addition, the hardware

This paper presents an analysis of the effects of heave plates with large skirts on the dynamics of a semi-submersible FOWT in waves. The analysis was based on a preliminary hull configuration envisaged for Brazilian waters. A numerical model based on linear frequency-domain hydrodynamics evaluated with panel methods was used for predicting the effects of the heave plates on the natural periods of

A numerical method for solving 3D unsteady potential flow problem of ship advancing in waves was put forward. The flow field was divided into an inner and an outer domain by introducing an artificial matching surface. The inner domain was surrounded by a ship-wetted surface and a matching surface as well as part of the free surface. The free-surface condition for the inner domain was formulated by

A new control method for autonomous underwater vehicle (AUV) is developed to achieve three-dimensional (3D) path following under ocean current disturbances when AUV lacks lateral and vertical driving forces. To make the control system more convenient for practical application and reduce the energy consumption of AUV, the controller is designed with relative velocities. To avoid the singularity problem

Autonomous navigation on the open sea involving automatic collision avoidance and route planning helps to ensure navigational safety. To judge whether all target ships (TSs) will pass safely and find the optimal route under multi-ship encounter situations, the relationship between the variations in the own ship (OS) velocity vector after nonlinear course altering motion and the collision avoidance

An integral equation method is developed to study the wave interaction with two symmetric permeable plates submerged in a two-layer fluid. The plates are inclined and penetrate the common interface between the layers. The existence of two different wave modes for the incident wave gives rise to two problems. Both of these are tackled by reducing them to a set of coupled hypersingular integral equations

Broaching-to, an uncontrollable maneuvering problem that may occur in following and quartering seas, can induce large roll motion and sometimes capsizing due to violent yaw motions, e.g., Nicholson (Some Parametric Model Experiment to Investigate Broaching-to, pp 160–166, 1974). Broaching-to arises when a ship cannot maintain its desired course even under maximum steering effort. Previous experiments

For damping the rolling motion of ship effectively and economically in rough sea, nonlinear feedback algorithm is implemented to control the fin stabilizer. Most of the researches paid attention to improve the performance of controller, while this paper turns attention to control the feedback error by a nonlinear function to reduce energy consumption. The controller and feedback error decorating constitutes

The research in underwater communication system is focused towards wireless networks in view of recent developments in wireless technology and increasing need for deep sea data mining. The underwater wireless optical communication (UWOC) have more advantages for short-range wireless links due to very high bandwidth and data rate than acoustic communication. Although UWOC offers high capacity links

This study develops a numerical simulation-based optimization procedure of Small Waterplane Area Twin Hull (SWATH) design. The procedure integrates the parametric geometry model, numerical analysis of total resistance, response surface methodology (RSM) model, and evolutionary optimization (EVOL) algorithm. The parametric hull form model is constructed based on general characteristic curves and several

In the present paper, the computational fluid dynamics (CFD) method is used to investigate the variation of linear and nonlinear wave loads on a 10-MW large-scale monopile offshore wind turbine under typical sea conditions in the eastern seas of China. The effect of adding a structural ice-breaking cone configuration close to the mean water level on the monopile’s hydrodynamic response is studied further

The hydrodynamic performance and lift-drag ratio of the underwater glider affected the state of its own operation. Therefore, a three-dimensional physical model and a mathematical model of a certain type of underwater glider are established. According to the principles of aircraft performance characterization, the fluid dynamics method was used to simulate the pressure distribution of the underwater

A numerical study of roughness effects at an actual ship scale is performed. Low-Reynolds number roughness models based on the two-equation turbulence model are employed, meanwhile, a wall function method is also developed. First, the roughness models are examined for the 2D flat plate case at the Reynolds numbers of \(1.0 \times 10^7\), \(1.0 \times 10^8\) and \(1.0\times 10^9.\) The resistance coefficient

Ship hull paint roughness considerably affects ship’s resistance. During the ship design stage, the added resistance coefficient, ΔCF, is used as the parameter of added resistance due to roughness. ΔCF is commonly estimated by the ITTC1978 formula using Ks as the roughness parameter. Ks is measured as the average hull roughness (AHR). AHR is composed of the average of Pt50 values (difference between

With the development of offshore oil production and the resulting application of riser pipes, it is necessary to get a better understanding of the flow-induced vibrations (FIV) phenomenon involving multiple cylindrical structures. In this scenario, little is available concerning the phase difference between the transverse displacements of two long rigid cylinders (aspect ratio of 30) in tandem and

In this study, to satisfy the urgent demand of vessel transportation marine service that are more standardized and intelligent, the vessel intelligent transportation maritime service portfolios in port areas (VITMSPPA) under e-navigation framework are proposed. First, we analyzed the qualitative description of vessel transportation maritime services in the maritime service portfolios. Thereafter, by

With an extreme load condition, the mooring system of a floating offshore wind turbine (FOWT) will be led to failure, such as mooring line breakage. However, the induced FOWT mooring line breakage in extreme gust still requires further study for design optimization in the future. In this paper, an aero-hydro-cable-servo time domain coupled simulation have been carried out of a NREL’s 5 MW OC4-DeepCwind

Accurate calculation of restoring moment, virtual mass moment of inertia and damping moment increases the accuracy of a ship’s dynamic stability simulation. The current methods of approximating the roll restoring moment are based on hydrostatic calculations. These methods fail to consider the dynamic conditions and variation of upward buoyancy and wave location with respect to the model. In the current

Autonomous Underwater Helicopter (AUH) is a novel dish-shaped multi-functional submersible vehicle in the autonomous underwater vehicle (AUV) family. Numerical study of launch and recovery system for AUVs from a research vessel is significant in the overall design. Single-arm crane and air-launch way are the important ways of launching AUVs with the high expertise and security. However, AUVs are still

This paper presents a method to efficiently calculate steady sailing conditions such as check helm, speed drop, hull drift angle, etc. of a ship moving in parallel to a bank wall under steady wind, together with the course stability at the equilibrium condition. Using this method, this study investigates the bank effect on the steady sailing condition and the course stability of a pure car carrier

A spring mounted rotating cylinder placed in flow is investigated using a two-dimensional newly improved discrete vortex method at Reynolds number of 105. In this study, the non-dimensional rotation rate, \(\alpha\) (rate of the cylinder surface velocity and flow velocity), varies from 0 to 16, and the reduced velocity \({\text{Ur}}\), increases from 1 to 14. The relationship between the wake formation

Planing crafts encounter large accelerations and motions when operated at high speeds in a seaway. To enhance their design and operability, accurate prediction of the accelerations and motions which these crafts will exhibit in a seaway is necessary. Here, validation and testing of a computational model for motion assessment of a planing craft in a seaway (MAPCS) are presented. To the best of the author’s