Vessel Navigation Research Articles

Approach an autonomous vessel as a single robot with Robot Operating System in virtual environment

ABSTRACT This project aims at developing an efficient simulation environment for the vessel navigation system. The design of the overall navigation system is described along with its application for the case study of an autonomous vessel. The UNITY and Robot Operating System were utilised as the virtual environment and the main control framework, respectively. By treating the autonomous vessel as a single robot, each part of the system was formulated to enhance the efficiency and visualisation in the development progresses for autonomous system. The virtual environment using UNITY overwhelms the space-time constraints in the testing stage. The navigation system combined with conventional navigation algorithms and a computer vision algorithm were implemented in the Robot Operating System. Hence, the navigation system was enhanced by an assistant object detection algorithm to be more active on fusing environment information. The excellence of the proposed object detection model was demonstrated with reliable performance with 94% mean Average Precision, which renders the model exhibiting visual sensibility in navigation. Overall, it is believed that this study can contribute to offering some insights into developing autonomous marine vessels.

Investigating the relationship between interannual closeness of ice coating and ice thickness in the Chukchi sea and water level variations

The hypothesis is tested that there is a significant relationship between changes in water surface level in some areas of the Chukchi Sea and variations in average ice cover thickness and cohesion in them, which can be used to refine short- and long-term forecasts of ice conditions. The results of the GLORYS12v1 global reanalysis and standard methods of mathematical statistics were used for verification. Changes in average ice cohesion were found to be correlated with changes in sea level in some areas from November to June. The correlation between sea level and average ice thickness is traceable only in December. The areas where this correlation is found include numerous sections of the coastal routes of the Northern Sea Route. It is noted that making medium- and long-term forecasts of the development of ice conditions in these areas can be significantly improved by taking into account the current changes in sea level. The identified regularities are important for ensuring safe and sustainable navigation along the Northern Sea Route during the internavigation period for independent navigation of vessels with high ice class and during the winter period when escorted by nuclear-powered icebreakers.

A new orchiopexy in lateral position for intraabdominal testis―One-staged laparoscopic testicular artery and gubernaculum sparing orchiopexy through inguinal canal using real-time vessel navigation with indocyanine green fluorescence to evaluate blood flow of testicular artery

A new orchiopexy in lateral position for intraabdominal testis―One-staged laparoscopic testicular artery and gubernaculum sparing orchiopexy through inguinal canal using real-time vessel navigation with indocyanine green fluorescence to evaluate blood flow of testicular artery

On the way to autonomous navigation

The national aspects of readiness and the tasks of introducing autonomous (unmanned) navigation in the near future are considered. The purpose of the study - identification of economic benefits and risks, problem areas of implementation of autonomous navigation technologies. The economic benefit is based on a reduction in the costs of paying the crew of the ship, living on board it, reducing losses from accidents. If the question what? has already been answered - the installation of autonomous navigation systems is available for naval vessels today, then the question why? has not yet been resolved. If the main benefit is expected from a reduction in crew, then a noticeable reduction in crew is possible only for newly built and relatively modern vessels with an auto- mation level of at least AUT2, the share of which under the flag of the Russian Navy is about 15%. At the same time, the modernization of existing inland navigation vessels into autonomous vessels is now available for less than 2% of the river transport fleet (vessels with an automation level of A1), which suggests that autonomous inland water transport only has to be built. The risks also include the slow pace of construction of new ships, as well as retraining and further employment with a massive reduction in the crew of ships. Foreign and domestic experience of the initial stage of autonomous navigation implementation is considered.

Analysis of modern hull structures dry cargo ships-representatives

The results of the analysis of the design of hull structures of modern dry cargo vessels-representatives of inland and mixed ("river-sea") navigation in comparison with classical vessels built in the twentieth century are presented. The characteristic damages of hull structures are considered, recommendations are given on the design of the main hull connections in accordance with the requirements of the Russian River Register (RRR) and the Russian Maritime Register of Shipping (MRS). It is noted that, taking into account the existing cargo flows on water transport, the hulls of inland navigation vessels of early construction are being modernized for operation in coastal marine areas. It is shown that, taking into account the aging of the fleet in modern conditions, a significant role is assigned to the construction of "super-full" vessels of internal and mixed ("river-sea") navigation, capable of delivering various cargoes without intermediate transshipment from seaports to river ports of the country.

АНАЛІЗ МОРСЬКИХ АВАРІЙ ЗА УЧАСТЮ КОНТЕЙНЕРОВОЗІВ

he research presents the analysis of statistics of the marine accidents involving container vessels, based on 22 marine accident investigation reports covering the period from 2012 to 2019. The analysis is intended to become the basis for specifying the key factors which affect the underestimation of risk assessment in the course of navigation of container vessels. Although the existing negative experience is set out in the investigation reports, which contain “case studies” with recommended avoiding actions, the tendancy of maritime accidents and incidents persists. Marine casualties considered are classified as very serious and serious marine casualties according to IMO Circular MSC-MEPC.3/Circ.3 “Casualty-related matters. Reports on marine casualties and incidents”. In order to study the trend of factors leading to marine accidents, the root causes were divided into two groups: primary and secondary. The study looks at the likelihood of several types of accidents within the specified period, defining the collisions as the most prevalent. Based on the correlation of the results, one of the cases was selected to be described in detail. Possible preventive safety measures for the respective marine accidents have been considered, highlighting the vital role of situational awareness at all times.

АНАЛІЗ МОРСЬКИХ АВАРІЙ ЗА УЧАСТЮ КОНТЕЙНЕРОВОЗІВ

The research presents the analysis of statistics of the marine accidents involving container vessels, based on 22 marine accident investigation reports covering the period from 2012 to 2019. The analysis is intended to become the basis for specifying the key factors which affect the underestimation of risk assessment in the course of navigation of container vessels. Although the existing negative experience is set out in the investigation reports, which contain “case studies” with recommended avoiding actions, the tendancy of maritime accidents and incidents persists. Marine casualties considered are classified as very serious and serious marine casualties according to IMO Circular MSC-MEPC.3/Circ.3 “Casualty-related matters. Reports on marine casualties and incidents”. In order to study the trend of factors leading to marine accidents, the root causes were divided into two groups: primary and secondary. The study looks at the likelihood of several types of accidents within the specified period, defining the collisions as the most prevalent. Based on the correlation of the results, one of the cases was selected to be described in detail. Possible preventive safety measures for the respective marine accidents have been considered, highlighting the vital role of situational awareness at all times. Keywords: container vessels, safety of navigation, serious marine accidents, situational awareness, collision.

Improvement of the procedure for issuing a permit for sailing vessels under a foreign flag by inland waterways of the Russian Federation

The article deals with the organization of navigation of vessels under the flags of foreign countries on the inland waterways of the Russian Federation. The article considers the relevance and problems of international shipping on inland waterways of the Russian Federation. Eurasian economic integration, international cargo flow "North-South". The most important inland waterways of international importance (IWWP), E-50 main waterways. It is proposed to improve the procedure for obtaining permission for navigation of vessels under the flags of foreign countries on inland waterways of the Russian Federation. A set of measures for the development of this type of activity is recommended. The analysis of receiving revenues from passage of vessels under flags of foreign states on inland waterways of the Russian Federation is carried out.

Recording of the ship’s motion in operation on irregular waves and its processing

The safety of the ship state during the voyage is ensured, among other things, by monitoring the state of the ship’s stability. A device for measuring the parameters of the ship’s motion and software for discrete motion recording into a computer have been developed in Siberian State University of Water Transport. With the use of the device, a full-scale experiment to record the motion of the motor ship “Grumant” during an operational voyage has been carried out. For this, the half-periods of rolling and their amplitudes are obtained. Amplitude-half-period distribution of rolling has been built. According to the maximum probability, the half-period of its own roll has been found from it, which makes it possible to assess the stability state of the vessel during the voyage. The spectrum of motion and rolling dispersion has been obtained. If it is possible to obtain objective information about the actual wave spectrum, this opens the way to obtaining the amplitude-frequency characteristic of the motion based on the Wiener- Khinchin theorem. This task is set as a priority for the development of research in this area with the prospect of optimizing vessel navigation in difficult hydrometeorological conditions.

Sediment Transport and Associated Long-term Bathymetric Changes due to Tidal Currents in The Seto Inland Sea, Japan

The topography of the seafloor is essential for determining physical phenomena such as ocean currents, favorable habitats for marine organisms, optimal vessel navigation, and so on. Prevailing currents and waves, as well as associated shear stresses acting on the ocean floor, are responsible for the formation of typical topographic features including sea caldrons and sandbanks through erosion of bedrock and sediments and their deposition processes. In the Seto Inland Sea (SIS), the most extensive semi-enclosed estuary in Japan, tidal currents affect pronouncedly the formation of seafloor topographic features; however, they have not been fully studied, particularly from a hydrodynamic viewpoint. This study aims to understand bathymetric formation under the predominance of tidal currents in the SIS. A 3-D high-resolution SIS circulation model based on the JCOPE2-ROMS system in a triple-nested configuration was utilized to examine the detailed hydrodynamic processes for the topography formations. A high correlation between the bottom shear stress and the scour depth of the erosive areas was observed, demonstrating that local tidal forcing has continuously been exerted on the seafloor to erode. A diagnostic sediment budget analysis was then conducted for sediments typical of the SIS, that is, gravel, sand, and clay, using the modeled circulation field. The horizontal divergence of the residual flows indicates consistency between divergence (convergence) and erosion (deposition). The sediment budget model also shows that these sediments are generally transported from deep to shallow areas in eroded terrains to form deposited terrains fringing the eroded terrains, whereas sedimentation tendency differs largely from location to location.

Digital information system for inland water transport vessels based on AIS

The most important role in ensuring navigation safety on inland waterways is played by the timely provision of navigators with timely and reliable navigational, meteorological and track information, as well as safety information. To solve this problem, the complexes of automatic identification stations’ coastal and ship networks deployed currently can be used. This communication channel (with free traffic for inland waterway transport) is currently used extremely ineffectively due to a small number of serviced vessels. The article substantiates the structure of a digital information system based on deployed networks of automatic identification stations for inland navigation vessels and its functional purpose. The issues of algorithmic and software support development for the process of preparation, transmission, reception and processing of transmitted information are considered. The structure of the database and algorithms for the formalized information packets’ formation in the direction of bank-to-ship are proposed. The formats of address and broadcast messages are presented. A variant of transmitting differential corrections to ships from control-correcting stations via networks of automatic identification stations without using the currently used radio channel is considered. The options for the dialog boxes of the digital information system for the dispatcher and the navigator are given.

Analysis of ice conditions of year-round navigation of Arc7 vessels in the southwestern part of the Kara Sea

Since 2006, a new generation of reinforced ice class Arc7 vessels has been operating on the Northern Sea Route. Safe and efficient sailing of this type of vessels in sea ice demands a detailed study of ice conditions. Accumulation and analysis of data on ice and hydrometeorological conditions for the entire Arctic in comparison with ice conditions along the route of vessels is an essential part of the development of optimal variants and optimal routes for ice navigation.The main aim of the study was to generalize the conditions of ice navigation of Norilskiy Nickel vessels along the optimal navigational routes in the south-western part of the Kara Sea. Based on the reports on sailing obtained from vessels of the “Norilskiy Nickel” type for the 2006–2014 period, we calculated the probability of choosing the optimal route along the Murmansk – Dudinka passage: through the Kara Gate Strait (seaward, central or coastal route) or the north of Cape Zhelaniya. During the year, vessels move predominantly through the Kara Gate. However, for three month per year, from April to June, the most appropriate route lies to the north of the Zhelaniya Cape. In April – May it is, on average, every second navigation, and in June – more than 80 % of all navigation. The features of the ice regime determining the choice of the specific navigation route, are described. The speeds of vessels of the “Norilskiy Nickel” type along various navigation routes in drifting sea ice of the Kara Sea are calculated. The fastest speed in drifting ice was recorded in the winter navigations of 2007–2008 and 2011–2012, in the January-May of these years the average speed was 10.2 and 11.2, correspondingly. The minimum speed in these years, even during the months of maximum ice cover growth, was not less than 4.8 knots. In other years, the average speeds were in the range of 9.2–9.8 knots. During the whole period of study, ice conditions that were extremely difficult for navigation formed three times: at the end of May 2009, at the end of March 2010 and in the middle of March 2011, these are considered in more detail in the present article.

Structural strength evaluation of a 3000 dwt river-barge, under oblique quasi-static design waves

The present study consists of the 3D-FEM global structural analysis of a typical open-top, double-hull, 3000 DWT inland navigation barge, having 90 m in length. The 3D-FEM model developed to perform the evaluation idealizes the barge structure with high accuracy, average element size being in the range of 50-75 mm. Two loading cases were analyzed, consisting of the ballast and full loading conditions. For the equilibrium floating condition in calm water and oblique design waves, an eigen iterative scheme has been used to generate the input parameters for the 3D-FEM analyzed cases. The push-barge finite element model has been subjected to oblique quasi-static design waves, headings ranging from 0 to 75 degrees. Wave heights considered in the analysis range from 0 to 1.2 m, step 0.3 m, corresponding to the Danube navigation conditions and freeboard limit imposed by the classification societies for inland navigation vessels. Numerical results following the FE analysis have been assessed by the yielding stress ratio, von Mises criterion, and the maximum deformation, thus indicating the structural areas that need to be improved in the design process.

The Role of Research and Innovation in Europe for the Decarbonisation of Waterborne Transport

Waterborne transport contributes to around 14% of the overall greenhouse gas emissions of transport in the European Union and it is among the most efficient modes of transport. Nonetheless, considering the aim of making the European Union carbon-neutral by 2050 and the fundamental role of waterborne transport within the European economy, effort is needed to reduce its environmental impact. This paper provides an assessment of research and innovation measures aiming at decreasing waterborne transport’s CO2 emissions by assessing European projects based on the European Commission’s Transport Research and Innovation Monitoring and Information System (TRIMIS). Additionally, it provides an outlook of the evolution of scientific publications and intellectual property activity in the area. The review of project findings suggests that there is no single measure which can be considered as a problem solver in the area of the reduction of waterborne CO2 emissions, and only the combination of different innovations should enable reaching this goal. The highlighted potential innovations include further development of lightweight composite materials, innovative hull repair methods, wind assisted propulsion, engine efficiency, waste heat electrification, hydrogen and alternative fuels. The assessment shows prevalence of funding allocated to technological measures; however, non-technological ones, like improved vessel navigation and allocation systems, also show a great potential for the reduction of CO2 emissions and reduction of negative environmental impacts of waterborne transport.

Autonomous Vessels in the Yangtze River: A Study on the Maritime Accidents Using Data-Driven Bayesian Networks

The prototypes of autonomous vessels are expected to come into service within the coming years, but safety concerns remain due to complex traffic and natural conditions (e.g., Yangtze River). However, the response of autonomous vessels to potential accidents is still uncertain. The accident prevention for autonomous vessels is unconvincing due to the lack of objective studies on the causation analysis for maritime accidents. This paper constitutes an attempt to cover the aforementioned gap by studying the potential causations for maritime accidents in the Yangtze River by using a Bayesian-based network training approach. More than two hundred accidents reported between 2013 and 2019 in the Yangtze River are collected. As a result, a Bayesian network (BN) is successfully established to describe the causations among different risk influencing factors. By analysing the BN, this study reveals that the occurrence of maritime accidents (e.g., collision, grounding) can be expected to reduce with the development of autonomous vessels as the crews are removed. However, the extent of the consequences from some accidents (e.g., fire, critical weathers) could be more serious than conventional ones. Therefore, more attention and thoughts are needed to ensure the safe navigation of autonomous vessels in the Yangtze River.

Looming in Forensics: Misapplication, Correction and Extension

In recent litigation Human Factors Experts have been misapplying the analysis of the looming threshold for offset motions. Looming (or image size expansion) analysis is appropriate for a rapid direct approach to an object (i.e., rear-end collisions) but is inappropriate for offset motions. Typically, looming threshold analysis is applied to nighttime driving when approaching a slow-moving or stopped vehicle presenting no visual cues other than rear tail lights. This paper lays out the foundation for looming, derives the accepted mathematical equation, and compares it to the rate of visual angle change, which is more applicable to offset motions. An appropriate offset looming threshold equation is derived. In addition, a special case of collision due to looming combined with lateral motion is addressed which has historical significance in open water vessel navigation.

Path-following Control for Autonomous Navigation of Marine Vessels Considering Disturbances

Path-following control is considered as one of the most fundamental skills to realize autonomous navigation of marine vessels in the ocean. This study addresses with the path-following control for a ship in which there are environmental disturbances in the directions of the surge, sway, and yaw motions. The guiding principle and back-stepping method was utilized to solve the ship’s tracking problem on the reference path generated by a virtual ship. For path-following control, error dynamics is one of the most important skills, and it extends to the research fields of automatic collision avoidance and automatic berthing control. The algorithms for the guiding principles and error variables have been verified by numerical simulation. As a result, most error variables converged to zero values with the controller except for the yaw angle error. One of the most interesting results is that the tracking errors of path-following control between two ships are smaller than the existing safe passing distances considering interaction forces from near passing ships. Moreover, a trade-off between tracking performance and the ship’s safety should be considered for determining the proper control parameters to prevent the destructive failure of actuators such as propellers, fins, and rudders during the path-following of marine vessels.

Vessel navigation risk and stern-swing index in sharp bend channels

Owing to the drastic change in flow conditions and river boundary of sharp bend channels, marine accidents occur frequently. A typical sharp bend channel was selected, whose flow velocity and navigation were studied by using a scaled hydrodynamic model and scaled vessel model maneuvering test. Based on the vessel speed, drift angle, and transverse flow velocity, the stern-swing index Δ was deduced, and a navigation risk model was established, which showed different navigation status and corresponding ranges of Δ. Transverse flow velocity is usually larger at the impact point of current on the river bank. The impact point moves downstream when flow rate increases. The hull undergoes swing, rotation, and drift under the combined action of current force and rudder force, the resultant moment caused by these two forces was represented by Δ. When the absolute value of Δ is in the range of 0–1.2, it can be used to judge the risk of a vessel passing through the sharp bend channel.

Robust trajectory tracking control for unmanned surface vessels under motion constraints and environmental disturbances

To achieve a fully autonomous navigation for unmanned surface vessels (USVs), a robust control capability is essential. The control of USVs in complex maritime environments is rather challenging as numerous system uncertainties and environmental influences affect the control performance. This paper therefore investigates the trajectory tracking control problem for USVs with motion constraints and environmental disturbances. Two different controllers are proposed to achieve the task. The first approach is mainly based on the backstepping technique augmented by a virtual system to compensate for the disturbance and an auxiliary system to bound the input in the saturation limit. The second control scheme is mainly based on the normalisation technique, with which the bound of the input can be limited in the constraints by tuning the control parameters. The stability of the two control schemes is demonstrated by the Lyapunov theory. Finally, simulations are conducted to verify the effectiveness of the proposed controllers. The introduced solutions enable USVs to follow complex trajectories in an adverse environment with varying ocean currents.

Fluorescence vessel and ureter navigation during laparoscopic lateral lymph node dissection.

Lateral lymph node metastasis in lower rectal cancer is considered a local disease in Japan, and guidelines suggest lateral lymph node dissection (LLND). However, laparoscopic procedures are relatively difficult. The ureter and hypogastric fascia must be dissected from the vesicohypogastric fascia to preserve the autonomic nerve and ureter. Additionally, lymph node dissection around the internal iliac artery is complex because many patterns of branching from the internal iliac artery exist. We investigated the utility of fluorescence ureter and vessel navigation using a near-infrared ray fluorescent ureteral catheter (NIRFUC) and indocyanine green (ICG). Fourteen patients who underwent laparoscopic LLND using fluorescence navigation were included. Eleven patients had rectal cancer, 1 had anal cancer, and 2 exhibited recurrence of rectal cancer. Eleven patients underwent NIRFUC insertion before surgery. Fluorescence vessel navigation (FVN) was performed with intraoperative ICG injections in 14 patients, with a total of 18 sides. The outcome measures were ureter navigation visibility, detection of the branch form from the internal iliac artery with FVN, differences between the fluorescence findings and anatomy of the internal iliac artery determined after LLND, and the surgical outcome. In all 11 patients, the ureters were clearly identified as fluorescent before dissection around the ureter. FVN revealed the internal iliac, umbilical, and superior vesical arteries in all patients. The branch from the internal iliac artery according to the Adachi classification was revealed on 16 sides (89%). The time from intravenous ICG injection to fluorescence of the internal iliac artery was 38 (17-57) s. The time from intravenous injection to when the vessels were observed as fluorescent was 113 (65-661) s. No ureteral or vessel injuries occurred. Fluorescence navigation of vessels and the ureter is feasible in laparoscopic LLND and has the potential to increase safety. Examination of fluorescence navigation for laparoscopic colorectal cancer surgery Research Ethics Committee of the Kawaguchi Municipal Medical Center (Saitama, Japan) approval number: 2020-3. https://kawaguchi-mmc.org/wp-content/uploads/clinicalresearch-r02.pdf.