Navigation Conditions Research Articles

Enhancing maritime safety: A comprehensive review of challenges and opportunities in the domestic ferry sector

The domestic ferry sector is uniquely distinctive owing to its challenging navigation conditions and vulnerable accident records that have evoked endless calls for improving maritime safety. The recent adoption of IMO model safety regulations offers viable options for the Member States to standardize incorporation into national law. The operations of domestic ferries range from very large vessels with freight to small craft, which are often the only transport means for a large population of commuters in the developing world. The flexibility of domestic ferries is appealing; on the other hand, their operations are a challenge to handle, raising the need to identify those challenges that are incompatible with smooth operations and business opportunities. The maritime industry, specifically regarding domestic ferry operations, confronts multilayered challenges with direct implications on accident prevention and operational safety that necessitate a thorough analysis for a comprehensive understanding. This study explores five categories, namely, operations, technology and innovations, the human element, policy and regulation, and economics, recognized as pivotal to improving maritime safety. Our content analysis identifies the comprehensive taxonomies, that explain the current challenges and practical opportunities faced by the sector and which are notably lacking, urging efficient tenacity to ensure sustainable domestic ferry operations. The primary objective was to enhance safety standards, promoting sustainable shipping for all stakeholders involved. This study has identified 28 challenges and 90 opportunities, providing a significant pathway for sustainable decision-making that also adds value to the safety of the stakeholders. This study is expected to explore novel and fertile future research areas to promote scholarly discussion in the domestic ferry sector. Highlights Policy deficiency - Recognition of inadequate policy frameworks for domestic ferry operations in developing nations, necessitating immediate alignment with international safety standards Governance strengthening - There is an swift need for strong governance structures to address deficiencies in policy formulation, regulatory enforcement, and operational practices, ensuring effective safety oversight Standardization challenges - The absence of standardized definitions and categorizations hampers the development of uniform safety regulations within the domestic ferry sector Capacity building - Continuous training programs are necessary to foster a safety-conscious culture among the domestic ferry workforce Policy adaptation - Policies must adapt to technological advancements, and collaboration with international bodies is vital for enhancing safety standards within the domestic ferry sector

A compensation method of carrier magnetic interference under pathological conditions for geomagnetic navigation

Geomagnetic navigation has become a hot spot in current research because of its characteristics of passiveness and good concealment. However, the magnetic interference from various ferromagnetic substances, electronic equipment, etc., of the carrier will be superimposed on the geomagnetic field, causing magnetometer measurement errors, thus affecting navigation accuracy. In practice, due to the limited maneuverability of the carrier, sufficient geomagnetic observation data cannot be obtained, resulting in the observation equation used for carrier magnetic interference compensation to be seriously pathological. To achieve the compensation of carrier magnetic interference, this paper proposes the total least squares method based on the ridge regression using the L curve to solve ridge parameters. This method can effectively suppress the measurement noise that exists on both sides of the observation equation, and is suitable for alleviating the pathological effects of carrier magnetic interference compensation. Experimental results show that the compensated magnetometer measurement error is reduced to 3% of the carrier magnetic interference by using the method proposed in this paper, which obtains more stable and accurate parameter estimates.

Adaptive dynamic safety domain for different sailing conditions

The problem of navigation safety is considered, in particular, the problem of developing an algorithm for an adaptive dynamic safety domain for various navigation conditions is investigated. The risk assessment of a ship approach situation is based on the safety domain as the minimum area around the ship into which an oncoming ship should not enter. Navigation conditions are considered in accordance with the rules of COLREG‑72 for navigation of vessels with limited visibility and being in sight of each other. To solve this problem, the navigation areas are classified. For further analysis, a table for the conditions and areas of navigation to identify the shape of the domains is created. The hydro meteorological situation, which takes into account the navigation conditions, and as a consequence, the need to increase the size of the safety domain, is considered. Changes in the parameters and shape of ship safety domains for different navigation conditions have been identified. For each district and navigation conditions, an original configuration of the security domain is proposed. The dynamic changes of the domain during movement in traffic separation systems and channels are separately considered. Using an example, a situation when the bow of the domain crosses the dividing line, which can lead to the appearance of false dangerous targets, is simulated. To avoid such situations, a dynamic domain with a changing shape in the form of an ellipse for swimming in a traffic separation system and channels, taking into account sailing conditions with limited visibility and in sight of each other is proposed. For the calculation, an algorithm to determine the shape of the domain under different visibility conditions and navigation areas has been compiled. Calculations for the case when the vessel enters a turn in traffic separation systems and narrow spaces have been performed. The deformation of the domain during rotation is shown.

Research on Speed Cooperative Control Strategy for Rudderless Dual-PMSM Propulsion Ships

In the navigation of rudderless dual-motor propulsion ships, it is often necessary for the dual motor to run stably at different given speeds. However, the existing coupling strategies cannot achieve precise cooperative control of the dual motor under different given commands. Therefore, in this study, we proposed a variable error difference compensation-coupling control (VEDC-CC) strategy. Simultaneously, a coupling compensation coefficient determination method based on the self-error difference of the dual motor was introduced. The VEDC-CC utilizes the self-error difference of the dual motor as the input for the coupling compensation controller, which enables the mutual coupling of self-errors, and effectively improves the cooperative controlling performance under different given commands. Moreover, the employed variable compensation coefficient determination method enhances the disturbance coupling performance and the response speed of the system. In this study, we analyzed the different navigation conditions and dual-propeller load characteristics of a rudderless dual-motor propulsion ship. Taking a rudderless dual-motor propulsion ship designed based on the cruise ship “Feng Hua Xue Yue” as the object, the VEDC-CC strategy was validated through simulation tests, considering the propeller load characteristics and actual operating conditions. The experimental results demonstrated that the VEDC-CC strategy could meet the practical control needs of the target ship.

Omsk Hydroelectric Power Plant Project in Economic History of Region in 1930s—1980s.

The article is dedicated to the unrealized project of the Omsk Hydroelectric Power Station, developed in the 1930s, then postponed and subsequently reintroduced for discussion in the 1980s. The sources used for this research include materials from the Historical Archive of the Omsk Region and the Russian State Archive of Economy. Both domestic and foreign historiography on the economic development of Western Siberia do not mention this project, hence this article aims to fill this historiographical gap. It is demonstrated that the project was considered by regional authorities solely as an agricultural facility, which would have allowed for the use of the reservoir for irrigation in the southern districts of the region and improvement of navigational conditions around the city of Omsk. Emphasis is placed on the fact that its implementation could have boosted the industrial development of the Omsk Region. The abandonment of the project in the 1930s largely determined the subsequent development of the region, particularly from an ecological perspective. To meet the energy needs of the city and the region, construction of thermal power plants began, fueled by Ekibastuz coal, which contains a large amount of ash. This, in turn, led to serious air pollution in the Omsk region, which continues to persist to this day.

PSO-Based Predictive PID-Backstepping Controller Design for the Course-Keeping of Ships

Ship course-keeping control is of great significance to both navigation efficiency and safety. Nevertheless, the complex navigational conditions, unknown time-varying environmental disturbances, and complex dynamic characteristics of ships pose great difficulties for ship course-keeping. Thus, a PSO-based predictive PID-backstepping (P-PB) controller is proposed in this paper to realize the efficient and rapid course-keeping of ships. The proposed controller takes the ship’s target course, current course, yawing speed, as well as predictive motion parameters into consideration. In the design of the proposed controller, the PID controller is improved by introducing predictive control. Then, the improved controller is combined with a backstepping controller to balance the efficiency and stability of the control. Subsequently, the parameters in the proposed course-keeping controller are optimized by utilizing Particle Swarm Optimization (PSO), which can adaptively adjust the value of parameters in various scenarios, and thus further increase its efficiency. Finally, the improved controller is validated by carrying out simulation tests in various scenarios. The results show that it improves the course-keeping error and time-response specification by 4.19% and 9.71% on average, respectively, which can efficiently achieve the course-keeping of ships under various scenarios.

Team CERBERUS Wins the DARPA Subterranean Challenge: Technical Overview and Lessons Learned

This article presents the CERBERUS robotic system-of-systems, which won the DARPA Subterranean Challenge Final Event in 2021. The Subterranean Challenge was organized by DARPA with the vision to facilitate the novel technologies necessary to reliably explore diverse underground environments despite the grueling challenges they present for robotic autonomy. Due to their geometric complexity, degraded perceptual conditions combined with lack of GNSS support, austere navigation conditions, and denied communications, subterranean settings render autonomous operations particularly demanding. In response to this challenge, we developed the CERBERUS system which exploits the synergy of legged and flying robots, coupled with robust control especially for overcoming perilous terrain, multi-modal and multi-robot perception for localization and mapping in conditions of sensor degradation, and resilient autonomy through unified exploration path planning and local motion planning that reflects robot-specific limitations. Based on its ability to explore diverse underground environments and its high-level command and control by a single human supervisor, CERBERUS demonstrated efficient exploration, reliable detection of objects of interest, and accurate mapping. In this article, we report results from both the preliminary runs and the final Prize Round of the DARPA Subterranean Challenge, and discuss highlights and challenges faced, alongside lessons learned for the benefit of the community.

Identification of the Bandwidth of a Magneto-Inertial Navigation Filter

We address the analysis of a nonlinear navigation filter used in Magneto-Inertial Dead-Reckoning (MIDR) whose input data are provided by a home-made device. This filter takes the measurements given by the magnetic sensors as inputs and returns the velocity of the body. Therefore, any unmodeled time-varying disturbance in the measurements impacts the estimation of the velocity and yields errors that distort the estimation. For dimensioning purpose, we aim to identify the bandwidth of the linearized part of this filter. To derive a model of this bandwidth, we first simplify our filter as a time-invariant Single-Input Single-Ouput (SISO) system in the situation where the steady-state regime is reached. The Best Linear Approximation (BLA) of this nonlinear system can hence be described by a conventional transfer function. We justify the validity of such a linear approximation for Extended Kalman Filters (EKF) and identify it with different methods, yielding a model for the bandwidth depending on the experimental conditions of navigation. We show that our filter is actually suitable for pedestrian navigation. Finally, simulations in realistic physical situations are used for validation.

Определение состояния аварийного корабля в процессе развития затопления отсеков

The article is focused on method of ship rolling processing during flooding of compartments. The main goal of such processing is in determination of the time moment, when the type of static stability diagram changes. The ship state corresponding to each of these types requires completely different methods of damage control, which is reflected in the knowledge base of the onboard intelligent system. In navigation conditions, and even more so in extreme situations, direct measurement of the stability characteristics of a marine object is impossible, so their indirect determination is required. The article presents the implementation of the procedural component of an on-board intelligent system based on an artificial neural network.

Interannual variability of ice cover across Davis Strait and the Labrador Sea for the period from 1979 to 2023

In conditions of rapid development of trade and transport communications, the issue of navigation through ice regime zones became of greater importance. In particular, reduction of the area of ice cover in the Canadian Arctic because of global warming opens up favourable prospects for further development of maritime shipping in this zone. Considering that the routes through the Northwest Passage are the shortest ones of all the routes connecting the Atlantic and Pacific oceans, it is clear that all aspects of this topic are of great importance and relevance. This especially applies to the aspects dedicated to studying the characteristics of appearance, formation, concentration, physical characteristics, trajectory of ice movement and forecasting the area of the ice cover in a given zone, i.e. the characteristics affecting the conditions of ice navigation and serving as determining factors in terms of navigation safety.
 The research examines some of these issues, namely the spread of the ice cover during the period of its maximum formation across Davis Strait and the Labrador Sea (where the routes through the Northwest Passage start) and the establishment of statistical relations between the ice spread and the temperatures of surface water and surface air. The research method to be used: synoptic-climatic and statistical analysis of numerical series of ice cover deviations from its average limit as of April 15 over the period of 1979-2023 within the zone in study.
 Based on the set goal, the study processed raw data on distribution of ice cover across Davis Strait and the Labrador Sea for the period of 1979-2023 and completed its statistical analysis. The results of the analysis showed presence of a statistically significant negative trend and cyclical fluctuations with periods of 3-6, 9, 10 and 13 years in relation to the interannual variability of ice cover distribution for the studied period. Positive trends are also observed in the interannual variability of surface water temperature and surface air temperature. After bringing the original series to a quasi-stationary form, a correlation analysis of the relationships between the ice cover distribution and the temperature of water and air was carried out. The results of the analysis determined zones and points with statistically significant correlation coefficients between them during the year. It turned out that the highest values of coefficients are observed from December to March, and the maximum one occurs in March.
 Systematization and analysis of the ice field across Davis Strait and the Labrador Sea during the period of maximum development made it possible to establish that the spread of ice between 60° and 55° north parallels was the most stable during the studied period, and the least stable was observed in the area below 55° north parallel.
 The results of the conducted research open up prospects for development of methods for forecasting the distribution of ice cover across Davis Strait and the Labrador Sea. This will make ice navigation in this area safer.

Optimization of river container port-access transport based on the innovatively designed electric ship in the Yangtze River Delta

In order to increase the share of the container port-access transport of river shipping and reduce the carbon emissions of container transportation, this study innovates the design of wide and shallow draft river ship and its electric power system based on the navigation condition of the rivers in the Yangtze River Delta (YRD) with the objective of raising the advantage in river shipping to truck transport. To validate the ship's practicability, we incorporate the carbon quota of container port-access transport as a constraint and build a model to optimize the river liner service for container port-access transport. The case study reveals that the adoption of innovative 48 TEU electric river ship for container port-access transport will be associated with a rise in the mode share of river liner shipping from 16.1% to 20.0%, a decrease in carbon emission by 0.124 million tons and a decrease of 0.358 billion CNY in container port-access transport in the YRD, while the higher the carbon tax price the more the modal shift will be, however, since the carbon emission cost is a part of the total transport cost, the total transport cost exhibits an upward trend.

Effect of Daily Regulation on Navigation Conditions in Deep Reservoirs

The daily regulation and anti-regulation of upstream and downstream power stations, respectively, frequently alter the river flow regime, velocity, and surface gradient, thus resulting in unsteady flow characteristics of the river and hindering shipping, waterway maintenance, and wharf operations. This study investigated the influence of daily regulation on the navigation conditions in the deep reservoir by taking the rivers between the Three Gorges Dam and the Gezhouba Dam as the research object. Prototype observations and a depth-averaged 2-D model were used to determine the main factors affecting the propagation law of unsteady flow. The propagation pattern of unsteady flow and channel navigational conditions and measures of the power station were analyzed systematically. The results showed that the water level amplitude was affected primarily by the peak amplitude and duration of the peak shaving. Additionally, the base flow significantly influenced time spatial distributions of the water level amplitude. Impacted by the reservoir storage capacity, a threshold for the duration of peak shaving was noted; this may result in maximum water level variation. As the peak shaving duration increased, the amplitude of the water level decreased. The research results can provide theoretical support for the optimization of hub shipping.

Impacts of 1.5 °C global warming on hydrological conditions of navigation along the Northern Sea Route and Northwest Passage

Arctic navigability is crucial to the global economy and landscape, while there is an omission in understanding how Arctic navigability changes as a function of 1.5 °C of the Paris Agreement. This study investigated the impact of 1.5 °C global warming above the preindustrial level on sea ice conditions and accessibility of the Northern Sea Route (NSR) and Northwest Passage (NWP) with the Polar Operational Limit Assessment Risk Indexing System and new risk demarcation criteria. The Arctic is colder on the Canadian side than on the European side under 1.5 °C warming. Sea ice is mostly less than three years old, and the younger, thinner and less concentrated ice is mainly in the seas along the NSR. Ships above Polar Class (PC) 6 might be unimpeded along two passages all the year. Besides, the NSR and NWP have great potential for PC6 ships in October–December, while it is only the NSR for PC7 ships. Caution is still required when navigating the western East Siberian Sea, its surrounding straits, and the Parry Channel. These changes in hydrological conditions are important for global shipping, and this work is helpful for supporting coordinated international decision-making.

Assessment and Characterization of Woji Creek Riverbed in Port Harcourt, Rivers State, Nigeria, Utilizing Side Scan Sonar Technology

Woji Creek plays a crucial role in vessel navigation, supports diverse flora and fauna habitats, and sustains local livelihoods. However, human activities and natural events have led to changes in its riverbed over time. Given its significance for coastal stability and geomorphology, there is a pressing need to classify, evaluate, and ensure its environmental sustainability. The primary objective of this study is to employ side scan sonar technology to classify and assess the riverbed of Woji Creek in Port Harcourt, Nigeria. The study aims to classify the riverbed, analyze water depth variations, evaluate navigational suitability, and determine turbidity levels within the creek. To achieve these objectives, the methodology involved acquiring Side-Scan Sonar (SSS) and Sub-bottom profile data. These datasets underwent backscatter processing to create geocoded backscatter images. Feature points were extracted and matched from these images to derive riverbed classification, depth categories, water volume distribution, and river turbidity analysis. The riverbed classification revealed the presence of three primary sediment types: Clayey Silty Sand, Silty Clay, and Silty Sand, each with distinct implications for navigation. Shallow, Moderate, Deep, and Very Deep areas were identified within Woji Creek, each influencing navigational conditions. Additionally, the water volume distribution analysis provided essential insights into depth limitations and route planning.
 Moreover, the assessment of river turbidity identified low, moderate, and high turbidity zones, reflecting water clarity and suspended particle levels. These findings serve as invaluable decision support tools for navigation planning and management in Woji Creek, offering comprehensive insights into the riverbed, depth suitability, volume distribution, and water quality. Leveraging this data can enhance strategic decision-making processes and contribute to the sustainable management of this vital waterway.

Impacts of Arctic Sea Fog on the Change of Route Planning and Navigational Efficiency in the Northeast Passage during the First Two Decades of the 21st Century

Under the background of climate change, the Northeast Passage’s navigability is on the rise. Arctic sea fog significantly influences navigational efficiency in this region. Existing research primarily focuses on routes accumulating the lowest distance, neglecting routes with the lowest time and sea fog’s influence on route planning and navigational efficiency. This study compares the fastest and shortest routes and analyzes Arctic sea fog’s impact on the Northeast Passage from June to September (2001–2020). The results show that coastal areas are covered with less sea ice under notable monthly variations. Sea fog frequency is highest near coasts, declining with latitude. September offers optimal navigation conditions due to minimal ice and fog. When only sea ice is considered, the fastest route is approximately 4 days quicker than the shortest. The shortest route has migrated towards the higher latitude over two decades, while the fastest route remains closer to the Russian coast. Adding the impact of sea fog on the fastest route, the speed decreased by 30.2%, increasing sailing time to 45.1%. The new fastest route considering both sea ice and sea fog achieved a 13.9% increase in sailing speed and an 11.5% reduction in sailing time compared to the original fastest route.

Smart carrot chasing guidance law for path following of unmanned surface vehicles

Carrot chasing guidance law is one of the most widely used path following algorithms due to its simplicity and ease of implementation; however, it has a fixed parameter which leads to large cross-tracking errors during different navigational conditions. This study proposes an innovative approach to carrot chasing algorithm to minimize cross-tracking errors. Pattern search optimization technique is integrated with carrot chasing guidance law to determine unique virtual target points obtained by flexible parameters instead of a fixed parameter. Proposed smart carrot chasing guidance law (SCCGL) provides stable and accurate path following even for different navigational conditions of unmanned surface vehicle (USV). To the best of our knowledge, we are the first to apply pattern search optimization technique to carrot chasing guidance law while USV is performing multi-tasks of predefined paths. This novelty significantly reduces both cross tracking errors and computational costs. Firstly, SCCGL is tested and compared with traditional carrot chasing algorithm in the numerical simulator for several navigational conditions such as different lists of waypoints, different initial locations, and different maximum turning rates of USV. SCCGL automatically determines optimal parameters to make stable and accurate navigation. SCCGL significantly reduces cross tracking errors compared to classical carrot chasing algorithm. This is the first contribution of this paper. Secondly, genetic algorithm optimization method has been implemented to carrot chasing guidance law instead of pattern search optimization technique. Genetic algorithm causes the total simulation time to be quite long. The proposed SCCGL (pattern search integrated carrot chasing guidance law) gives optimum results 20 times faster than the genetic algorithm. This is the second and main contribution of developed SCCGL method. It is observed that SCCGL provides best navigation with minimum cross-tracking errors and minimum computational cost compared to the classical carrot chasing algorithm and other optimization technique.

Reduced and More Fragmented Mississippi River Navigability by Rising Flow

AbstractThe Mississippi River System (MRS) is one of the most important commercial routes in the world and its navigability is critical for anticipating potential disruptions in the global supply chain. Here we show that the navigability of the MRS has reduced since 1963, especially in the lower part of the basin. Based on analyses of daily stage time series and the associated conditions for navigation, we find that high rather than low water levels are the main culprits for the observed navigability issues. Moreover, not only have the navigable days decreased, but navigation without operational restrictions has also become more fragmented. Our findings provide basic information toward the development of strategies to mitigate potential negative effects in the U.S. navigation sector.

Hybrid Path Planning for Unmanned Surface Vehicles in Inland Rivers Based on Collision Avoidance Regulations.

In recent years, with the continuous advancement of the construction of the Yangtze River's intelligent waterway system, unmanned surface vehicles have been increasingly used in the river's inland waterways. This article proposes a hybrid path planning method that combines an improved A* algorithm with an improved model predictive control algorithm for the autonomous navigation of the "Jinghai-I" unmanned surface vehicle in inland rivers. To ensure global optimization, the heuristic function was refined in the A* algorithm. Additionally, constraints such as channel boundaries and courses were added to the cost function of A* and the planned path was smoothed to meet the collision avoidance regulations for inland rivers. The model predictive control algorithm incorporated a new path-deviation cost while imposing a cost constraint on the yaw angle, significantly minimizing the path-tracking error. Furthermore, the improved model predictive control algorithm took into account the requirements of rules in the cost function and adopted different collision avoidance parameters for different encounter scenarios, improving the rationality of local path planning. Finally, the proposed algorithm's effectiveness was verified through simulation experiments that closely approximated real-world navigation conditions.

Risk analysis of bridge ship collision based on AIS data model and nonlinear finite element

Abstract To solve the problem of calculating the probability of ship collision in ship bridge collision risk assessment, the impact parameters of ship collision are obtained based on the automatic identification system (AIS) data to solve the problem that the existing methods do not consider the actual navigable ship information in a specific bridge navigation area. Based on AIS data, the dynamics of sailing ships are analyzed, parameters such as ship position, speed, and yaw angle, are obtained, ship traffic flow is analyzed, and the geometric probability in the actual ship traffic flow specification model is modified. The results before and after correction were compared and analyzed. The results show that the maximum transverse displacement of the anti-collision device is about 1.5 s under all working conditions, indicating that the collision force drops continuously from this moment to 0 in the collision force time history. In the process of collision, the anti-collision device absorbs part of the collision energy through its own deformation. Under the premise of a certain initial kinetic energy, the deformation caused by the collision energy absorption after fortification will be reduced. The anti-collision device has local permanent deformation under the impact of 5,000 t ship, but no damage and failure, and will not cause water entry and subsidence. It proves that the constructed fishery ship collision risk assessment model and the developed fishery ship safety management and evaluation system are reliable and the prediction results are credible, which can provide scientific methods for the safety management and evaluation of fishery vessels. For the bridge area with complicated ship navigation conditions, it is necessary to use the actual navigable ship information obtained based on AIS data to estimate the distribution of ships in the bridge area to improve the accuracy of the calculation results.

Stochastic Modeling of Sea Ice Concentration to Assess Navigation Conditions along the Northern Sea Route

Stochastic Modeling of Sea Ice Concentration to Assess Navigation Conditions along the Northern Sea Route