Scientific portfolio 🛳️

The autonomous navigation system of a sea-going vessel

We propose an integrated comprehensive system of an Autonomous Surface Vessel (ASV), dedicated to ships with various degrees of autonomy. The system performs a variety of tasks aimed at safe voyage execution. The use of basic and additional information sources is envisaged, including data from unmanned remotely controlled and autonomous aerial vehicles, to increase situational awareness. After defining the assumptions and devising the architecture of the system, we built its model. The key elements of the model, collision avoidance and automatic communication modules, are capable of developing and agreeing on manoeuvres between autonomous vessels in the negotiation process. The model was implemented as a real time system and verified in three stages: laboratory tests, quasi-real tests using physical models of ships and in real operational conditions on board ships at sea. The research results have confirmed the correctness of the assumptions, designed system architecture and developed algorithms.

Modeling and Simulation of Ship Motion in Excessive Approach Situations

This monograph is a kind of summary of the results and work carried out by the author as part of the Diamond Grant project in the years 2019-2022. It is devoted to the issues of modeling the movement of a sea vessel and the use of the MMG (Mathematical Modeling Group) mathematical model to simulate selected anti-collision maneuvers that allow collision avoidance or minimization of the predicted effects. According to the author's assumption, the monograph has a holistic layout. In addition to the results of numerical simulations of last-minute maneuvers, considerations are presented on the theoretical aspects of mathematical modeling of ship motion and the influence of the marine environment, as well as modeling of ship collision dynamics. The aim was to create a publication that allows you to reproduce the presented results and implement the presented algorithms. Hence, the emphasis was placed on presenting the algorithms in the form of block diagrams, and the equations being elements of the mathematical model in the explicit form. At the same time, complete sets of parameters for three sample variants of ships were provided. The described mathematical model itself has a modular structure and the presented elements relating to various hydrodynamic aspects of the ship as well as weather or bathymetric conditions of the basin can be properly included or omitted depending on expectations and needs. It is intended for people interested in the use of numerical simulations, mathematical modeling or practical implementations of navigation and anti-collision algorithms in information systems.

Full Sea Trial Based Estimation of Hydrodynamic Derivatives of a Research Vessel

The study aims to generate a set of hydrodynamic coefficients allowing for amanoeuvring simulation of an existing vessel. Several full-scale trials of a research vessel mv NawigatorXXI were carried out. A set of hydrodynamic derivatives based on pre-existing semi-empiricalformulae was formed and used as a starting point in the tuning phase. The set was tuned sothat the summarised error of manoeuvring indices between the simulation and theexperimental data would be minimised. A set of hydrodynamic derivatives named N7 was obtained. It allows for asimulation of manoeuvring capabilities of an existing research vessel with satisfactoryaccuracy. The pre-existing mathematical model MMG can be supplied with anN7 set generated and tuned in the following study for further simulations of manoeuvres or inderivative studies i.e. concerning planning realistic collision avoidance manoeuvres or trackoptimisation. The obtained set of hydrodynamic coefficients N7 can be successfully usedfor simulation of mv Nawigator XXI manoeuvrability as it is a new vessel, never previouslysimulated using an existing and popular MMG model.

Beam Search Algorithm for Anti-Collision Trajectory Planning for Many-to-Many Encounter Situations with Autonomous Surface Vehicles

A single anti-collision trajectory generation problem for an “own” vessel only is significantly different from the challenge of generating a whole set of safe trajectories for multi-surface vehicle encounter situations in the open sea. Effective solutions for such problems are needed these days, as we are entering the era of autonomous ships. The article specifies the problem of anti-collision trajectory planning in many-to-many encounter situations. The proposed original multi-surface vehicle beam search algorithm (MBSA), based on the beam search strategy, solves the problem. The general idea of the MBSA involves the application of a solution for one-to-many encounter situations (using the beam search algorithm, BSA), which was tested on real automated radar plotting aid (ARPA) and automatic identification system (AIS) data. The test results for the MBSA were from simulated data, which are discussed in the final part. The article specifies the problem of anti-collision trajectory planning in many-to-many encounter situations involving moving autonomous surface vehicles, excluding Collision Regulations (COLREGs) and vehicle dynamics.

Beam Search Algorithm for Ship Anti-Collision Trajectory Planning

The biggest challenges in the maritime environment are accidents and excessive fuelconsumption. In order to improve the safety of navigation at sea and to reduce fuel consumption,the strategy of anti-collision, shortest trajectory planning is proposed. The strategy described in thispaper is based on the beam search method. The beam search algorithm (BSA) takes into account manysafe trajectories for the present ship and chooses the best in terms of length and other criteria. Therisk of collision of present ship with any target ships is detected when the closest point of approach(CPA) of the present ship is violated by the target ship’s planned trajectory. Only course alteration ofthe present ship is applied, and not speed alteration. The algorithm has been implemented in thedecision support system NAVDEC and tested in a real navigation environment on the m/f Wolin,a Polish ferry. Almost all BSA trajectories calculated were shorter in comparison to the standardNAVDEC-calculated algorithm.

Autonomous Vessels' Pathfinding Using Visibility Graph

The aim of this paper is to present an algorithm forpathfinding in confined environment. Initially, the state of artconcerning route generation is provided and briefly discussed.Specific geographical terrain is provided and converted into two-dimensional polygon-shaped environment. Several scenarios ofinitial and destination points for ship’s journey are provided, forall of which a trajectory is generated using visibility graphmethod (VGM). The main purpose of the article is underlined inthe section providing results of a numerical experiment ongenerating path to follow for a seaborne object in mentionedconfined environment. The paper is concluded with a discussionregarding application of said algorithms in autonomous vessels’technology as well as with an assessment of the algorithm’sefficiency.

Analysis of Possibilities How Collision Between Kraslava and Atlantic Lady Could Have Been Avoided

The report presents the simulation results of a collision between m/v Kraslava and m/v Atlantic Lady. The analysis was performed by mutual means of navigation decision support system (NDSS) in collision situations and software designed to generate maneuvering simulations of maritime vessels. NAVDEC works out anti-collision manoeuvre using AIS (Automatic Identification System) and ARPA (Automatic Radar Plotting Aids) data, furthermore, the manoeuvring calculations stem from ships' hull and engine data. Then they are processed by specialized computing algorithms and presented to the operator on a display in the alphanumeric and graphic forms. The data on the specific navigational situation from the report of Danish Maritime Accident Investigation Board was used for the generation of signals transmitted to NDSS as a sequence of NMEA strings.

Numerical analysis of MOB manoeuvres in regard to a body suffering from hypothermia

The following paper’s aim is to provide a numerical analysis of well-known man overboard (MOB) manoeu-vres undertaken by vessels’ masters’ in critical situations, when a passenger or crew member falls out froma vessel. The simulation, based on a complex hydrodynamical model of a merchant ship, which compares3 variants of this manoeuvre, shows that the Scharnov turn is the shortest and the quickest one, but the shipfinishes the Anderson turn with the lowest velocity. Also, the time of the Williamson turn is short enough, tosuccessfully finish the operation. The duration of MOB manoeuvres is likened to the results of a medical over-view, with not only the duration of MOB, but also the time between falling overboard and the beginning of themanoeuvre playing a crucial role in saving a casualty’s life.

Mathematical Principles for Vessel’s Movement Prediction

The following paper presents novel approach to mathematical vessel’s movement prediction and incoming manoeuvre estimation by proposing non-linear approximation. The stated calculus aims to derive formulas allowing any tracking and traffic systems to estimate position of a nautical vessel in a shortterm future, which bases on data analysis via polynomial equation approximation technique. A numerical example is intended to prove possibilities of potential application in navigational decision support systems and in manoeuvring operations either in port or in open sea. Ultimately the calculus is compared to other parallel mathematical tools, widely used for proposition of vessel’s position behaviour as a function of time, in order to contemplate the constatation of positive application’s value.

Naval Artificial Intelligence

The following paper focuses on an analysis of a comprehensive system of nautical vessel’sartificial intelligence. Such a complex structure should compromise a number of parallel major and minoritems of vessel’s equipment in order to maintain correct management of the vessel itself. Stemming fromindividual interests of the authors, an attempt to generalize a theoretical basis for a naval artificial intelligence(NAI) is presented. The definition of NAI and its components is derived and discussed. Schematics of analgorithm is proposed; the NAI as a virtual managing party of a vessel’s deck and engine department,maintaining safe navigation and the freightage of the cargo as well as harbour operations.

Model Research of Navigational Support System Cooperation in Collision Scenario

The purpose of following paper is to analyse how a navigational support system would behave in a collision situation upon encountering another vessel also steered by a NSS. This case study of two AI-driven vessels is executed under laboratory circumstances within the use of Navdec System, a navigational decision support tool established as a direct aid to the vessel’s bridge Officer team. Decisions undertaken by the Navdec are compared to the experience-based choices of the Master in the exact case. Latter analysis of experiment’s outcome is given as a premise for the real introduction of a NSS into practical use.

Relevance of the Relativistic Effects in Satellite Navigation

Position determination of Global Navigation Satellite Systems (GNSS) depends on the stability and accuracy of the measured time. However, since satellite vehicles (SVs) travel at velocities significantly larger than the receivers and, more importantly, the electromagnetic impulses propagate through changing gravitational potentials, enormous errors stemming from relativity-based clock offsets would cause a position error of about 11 km to be accumulated after one day. Based on the premise of the constancy of light, two major relativistic effects are described: time dilation and gravitational-frequency shift. Following the individual interests of the author, formulas of both are scrupulously derived from generaland special-relativity theory principles; moreover, in the penultimate section, the equations are used to calculate the author’s own numerical values of the studied parameters for various GNSSs and one Land Navigation Satellite System (LNSS).

An Analysis of Possibilities How the Collision Between M/V ‘Baltic Ace’ and M/V ‘Corvus J’ Could Have Been Avoided

The report presents the simulation results of collision between m/v ‘Baltic Ace’ and m/v ‘Corvus J’. The analysis was performed by means of navigation decision support system (NDSS) in collision situations. This system (NAVDEC) works out anti-collision manoeuvre using AIS (Automatic Identification System) and ARPA (Automatic RadarPlotting Aids) data. Then they are processed by specialized computing algorithms andpresented to the operator on a display in the alphanumeric and graphic forms. The data on the specific navigational situation from the report of Bahamas Maritime Authority was used for the generation of signals transmitted to NDSS as a sequence of NMEA string