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Journal articles on the topic 'Ship Collision'
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1
Kim, Dong-Gyun, Katsutoshi Hirayama, and Gyei-Kark Park. "Collision Avoidance in Multiple-Ship Situations by Distributed Local Search." Journal of Advanced Computational Intelligence and Intelligent Informatics 18, no. 5 (September 20, 2014): 839–48. http://dx.doi.org/10.20965/jaciii.2014.p0839.
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As vital transportation carriers in trade, ships have the advantage of stability, economy, and bulk capacity over airplanes, trucks, and trains. Even so, their loss and cost due to collisions and other accidents exceed those of any other mode of transportation. To prevent ship collisions many ways have been suggested, e.g., the 1972 COLREGs which is the regulation for preventing collision between ships. Technologically speaking, many related studies have been conducted. The term “Ship domain” involves that area surrounding a ship that the navigator wants to keep other ships clear of. Ship domain alone is not sufficient, however, for enabling one or more ships to simultaneously determine the collision risk for all of the ships concerned. Fuzzy theory is useful in helping ships avoid collision in that fuzzy theory may define whether collision risk is based on distance to closest point of approach, time to closest point of approach, or relative bearing – algorithms that are difficult to apply to more than one ships at one time. The main purpose of this study is thus to reduce collision risk among multiple ships using a distributed local search algorithm (DLSA). By exchanging information on, for example, next-intended courses within a certain area among ships, ships having the maximum reduction in collision risk change courses simultaneously until all ships approach a destination without collision. In this paper, we introduce distributed local search and explain how it works using examples. We conducted experiments to test distributed local search performance for certain instances of ship collision avoidance. Experiments results showed that in most cases, our proposal applies well in ship collision avoidance amongmultiple ships.
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Zhang, Ke, Liwen Huang, Xiao Liu, Jiahao Chen, Xingya Zhao, Weiguo Huang, and Yixiong He. "A Novel Decision Support Methodology for Autonomous Collision Avoidance Based on Deduction of Manoeuvring Process." Journal of Marine Science and Engineering 10, no. 6 (June 1, 2022): 765. http://dx.doi.org/10.3390/jmse10060765.
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In the last few years, autonomous ships have attracted increasing attention in the maritime industry. Autonomous ships with an autonomous collision avoidance capability are the development trend for future ships. In this study, a ship manoeuvring process deduction-based dynamic adaptive autonomous collision avoidance decision support method for autonomous ships is presented. Firstly, the dynamic motion parameters of the own ship relative to the target ship are calculated by using the dynamic mathematical model. Then the fuzzy set theory is adopted to construct collision risk models, which combine the spatial collision risk index (SCRI) and time collision risk index (TCRI) in different encountered situations. After that, the ship movement model and fuzzy adaptive PID method are used to derive the ships’ manoeuvre motion process. On this basis, the feasible avoidance range and the optimal steering angle for ship collision avoidance are calculated by deducting the manoeuvring process and the modified velocity obstacle (VO) method. Moreover, to address the issue of resuming sailing after the ship collision avoidance is completed, the Line of Sight (LOS) guidance system is adopted to resume normal navigation for the own ship in this study. Finally, the dynamic adaptive autonomous collision avoidance model is developed by combining the ship movement model, the fuzzy adaptive PID control model, the modified VO method and the resume-sailing model. The results of the simulation show that the proposed methodology can effectively avoid collisions between the own ship and the moving TSs for situations involving two or multiple ships, and the own ship can resume its original route after collision avoidance is completed. Additionally, it is also proved that this method can be applied to complex situations with various encountered ships, and it exhibits excellent adaptability and effectiveness when encountering multiple objects and complex situations.
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Li, Weifeng, Lufeng Zhong, Yaochen Liu, and Guoyou Shi. "Ship Intrusion Collision Risk Model Based on a Dynamic Elliptical Domain." Journal of Marine Science and Engineering 11, no. 6 (May 26, 2023): 1122. http://dx.doi.org/10.3390/jmse11061122.
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To improve navigation safety in maritime environments, a key step is to reduce the influence of human factors on the risk assessment of ship collisions by automating the decision-making process as much as possible. This paper optimizes a dynamic elliptical ship domain based on Automatic Identification System (AIS) data, combines the relative motion between ships in different encounter situations and the level of ship intrusion in the domain, and proposes a ship intrusion collision risk (SICR) model. The simulation results show that the optimized ship domain meets the visualization requirements, and the intrusion model has good collision risk perception ability, which can be used as the evaluation standard of ship collision risk: when the SICR is 0.5–0.6, the ship can establish a collaborative collision avoidance decision-making relationship with other ships, and the action ship can take effective collision avoidance action at the best time when the SICR is between 0.3 and 0.5. The SICR model can give navigators a more accurate and rapid perception of navigation risks, enabling timely maneuvering decisions, and improving navigation safety.
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Cheng, Zhiyou, Yaling Li, and Bing Wu. "Early Warning Method and Model of Inland Ship Collision Risk Based on Coordinated Collision-Avoidance Actions." Journal of Advanced Transportation 2020 (July 20, 2020): 1–14. http://dx.doi.org/10.1155/2020/5271794.
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To reduce the occurrence of ship collisions, immediate danger, and close-quarters situations in narrow inland waterways, a step-by-step early warning system for ship collision-avoidance actions was developed, along with an early warning method and model of collision risk based on coordinated collision-avoidance actions. This study first analyzed the importance of coordinated collision-avoidance actions in inland waterways, and the process and key components of coordinated collision-avoidance actions were studied. Then, the early warning method of inland ship collision risk based on coordinated collision-avoidance actions was introduced; the effectiveness of the early warning method was comparatively analyzed via experimental observations. A framework of early warning model of inland ship collision risk was created based on the early warning method; a collision risk early warning model for inland ships based on coordinated collision-avoidance actions was proposed according to the relationship between the distance/time to the closest point of approach (DCPA, TCPA), coordination degree of collision-avoidance actions of the two considered ships and collision risk; moreover, the early warning model of inland ship collision risk was further considered for quantitative calculation. Finally, the application of the early warning method and model was demonstrated using a case study. The results indicate that the early warning method of inland ship collision risk based on coordinated collision-avoidance actions could effectively reduce the emergence of close-quarters situations and immediate danger, and the early warning model could quantitatively show the evolution of collision risk of two ships along with the process of coordinated collision-avoidance actions.
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Li, Yun, and Haiyu Zhang. "Collision Avoidance Decision Method for Unmanned Surface Vehicle Based on an Improved Velocity Obstacle Algorithm." Journal of Marine Science and Engineering 10, no. 8 (July 29, 2022): 1047. http://dx.doi.org/10.3390/jmse10081047.
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To ensure navigation safety, unmanned surface vehicles (USVs) need to have autonomous collision avoidance capability. A large number of studies on ship collision avoidance are available, and most of these papers assume that the target ships keep straight or follows the International Regulations for Preventing Collisions at Sea (COLREGS). However, in the actual navigation process, the target ship may temporarily turn. Based on the above reasons, this paper proposes a multi-ship collision avoidance decision method for USVs based on the improved velocity obstacle algorithm. In the basic dynamic ship domain model, a collision risk model is constructed to improve the accuracy of the risk assessment between the USV and target ships. The velocity obstacle algorithm is combined with the dynamic ship domain, and the collision avoidance timing and method are judged according to the collision risk. The simulation results show that the decision method can handle the situation that the target ship temporarily turns and has an emergency collision avoidance capability. Compared with the traditional VO algorithm, the collision avoidance time of the method is shorter, and the number of course changes is less.
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Gong, Haonan. "Application of Viscoelastic Materials in Ship Collision." Journal of Contemporary Educational Research 5, no. 11 (November 30, 2021): 118–24. http://dx.doi.org/10.26689/jcer.v5i11.2690.
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With the expansion of global trade routes, ship collision has become a major problem. This article proposes an approach by laying viscoelastic material on the inner side of the ship to increase the crashworthiness. By using the nonlinear finite element model software, this study simulates ship collisions as well as models and analyzes ships along with viscoelastic materials. The results from the simulation suggest that viscoelastic materials can effectively protect ships during collisions.
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Wei, Guan, and Wang Kuo. "COLREGs-Compliant Multi-Ship Collision Avoidance Based on Multi-Agent Reinforcement Learning Technique." Journal of Marine Science and Engineering 10, no. 10 (October 4, 2022): 1431. http://dx.doi.org/10.3390/jmse10101431.
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The congestion of waterways can easily lead to traffic hazards. Moreover, according to the data, the majority of sea collisions are caused by human error and the failure to comply with the Convention on the International Regulation for the preventing Collision at Sea (COLREGs). To avoid this situation, ship automatic collision avoidance has become one of the most important research issues in the field of marine engineering. In this study, an efficient method is proposed to solve multi-ship collision avoidance problems based on the multi-agent reinforcement learning (MARL) algorithm. Firstly, the COLREGs and ship maneuverability are considered for achieving multi-ship collision avoidance. Subsequently, the Optimal Reciprocal Collision Avoidance (ORCA) algorithm is utilized to detect and reduce the risk of collision. Ships can operate at the safe velocity computed by the ORCA algorithm to avoid collisions. Finally, the Nomoto three-degrees-of-freedom (3-DOF) model is used to simulate the maneuvers of ships. According to the above information and algorithms, this study designs and improves the state space, action space and reward function. For validating the effectiveness of the method, this study designs various simulation scenarios with thorough performance evaluations. The simulation results indicate that the proposed method is flexible and scalable in solving multi-ship collision avoidance, complying with COLREGs in various scenarios.
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Li, Qiang. "A Research on Autonomous Collision Avoidance under the Constraint of COLREGs." Sustainability 15, no. 3 (January 30, 2023): 2446. http://dx.doi.org/10.3390/su15032446.
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In this paper, a decision-making model suitable for the collision avoidance (CA) of numerous target ships (TSs) is proposed, based on the principle of ship collision avoidance geometry and the characteristics of numerous target ships’ collision avoidance at sea. To ensure that the collision avoidance behaviors of own-ship (OS) are subject to the International Regulations for Preventing Collisions at Sea (COLREGS), this paper gives full consideration to the requirements of COLREGS within the scope of CA action and the time of collision avoidance. A ship CA simulation is established based on the Mathematical Modeling Group (MMG) model. To optimize the CA decision-making model, the influence of hydrodynamic force on steering time required to reach the new course is integrated into the collision avoidance simulation system. The simulation results show that the method can quickly and effectively determine a collision avoidance decision under the complex situation of numerous target ships and static obstacles, and it can consider the unpredictable strategies used by other vessels.
9
Weng, Jinxian, Guorong Li, Tian Chai, and Dong Yang. "Evaluation of Two-Ship Collision Severity using Ordered Probit Approaches." Journal of Navigation 71, no. 4 (February 1, 2018): 822–36. http://dx.doi.org/10.1017/s0373463317000996.
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This study develops an ordered probit model to evaluate the factors influencing two-ship collision severity using ten years’ ship collision accident data from Fujian sea areas. The model results show that the involvement of big ships has the largest impact in increasing the probability of a serious or very serious accident, followed by the involvement of fishing vessels. There will be a bigger probability of a serious accident if both ships involved in the collision are cargo ships. We found that the season of spring, poor visibility and night time periods are more likely to be factors in high severity levels of ship collision. The results also reveal that lookout failure plays a decisive role in increasing serious accident risk compared with other types of human errors. The results of this study may be beneficial for policy-makers in proposing efficient strategies to reduce the likelihood of serious ship collisions.
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Wang, Zhiyuan, Yong Wu, Xiumin Chu, Chenguang Liu, and Mao Zheng. "Risk Identification Method for Ship Navigation in the Complex Waterways via Consideration of Ship Domain." Journal of Marine Science and Engineering 11, no. 12 (November 29, 2023): 2265. http://dx.doi.org/10.3390/jmse11122265.
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Collision risk identification is an important basis for intelligent ship navigation decision-making, which evaluates results that play a crucial role in the safe navigation of ships. However, the curvature, narrowness, and restricted water conditions of complex waterways bring uncertainty and ambiguity to the judgment of the danger of intelligent ship navigation situation, making it difficult to calculate such risk accurately and efficiently with a unified standard. This study proposes a new method for identifying ship navigation risks by combining the ship domain with AIS data to increase the prediction accuracy of collision risk identification for ship navigation in complex waterways. In this method, a ship domain model is constructed based on the ship density map drawn using AIS data. Then, the collision time with the target ship is calculated based on the collision hazard detection line and safety distance boundary, forming a method for dividing the danger level of the ship navigation situation. In addition, the effectiveness of this method was verified through simulation of ships navigation in complex waterways, and correct collision avoidance decisions can be made with the Regulations for Preventing Collisions in Inland Rivers of the People’s Republic of China, indicating the advantages of the proposed risk identification method in practical applications.
11
Argüelles, Reyes Poo, Jesús A. García Maza, and Felipe Mateos Martín. "Specification and Design of Safety Functions for the Prevention of Ship-to-Ship Collisions on the High Seas." Journal of Navigation 72, no. 1 (August 2, 2018): 53–68. http://dx.doi.org/10.1017/s0373463318000553.
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Maritime accident statistics reveal that ship collisions are among the most frequent and severe accidents. The same statistics indicate that most of them are caused by human error, mainly due to breaches of the International Regulations for Preventing Collisions at Sea (COLREGs) and to the lack of communication between ships. There are also special situations where there is some ambiguity in the application of the COLREGs. In such occasions, and if there is no communication between the ships involved, compliance with the Rules may still end up in a collision. This article brings a new approach to Collision Avoidance Systems (CAS) and presents the earliest stages in the development of safety functions for the reduction of ship-to-ship collision risk on the high seas. These functions will help the concerned ships achieve coordinated compliance with the COLREGs. Functional safety standards are applied and, in their implementation, real, accessible electronic programmable systems (hardware and software) will be used.
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Weng, Jinxian, Shiguan Liao, and Guorong Li. "Bayesian Regression Model for Estimating Economic Loss Resulting from Two-Ship Collisions." Transportation Research Record: Journal of the Transportation Research Board 2673, no. 1 (January 2019): 164–72. http://dx.doi.org/10.1177/0361198118821599.
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This study aims to develop a Bayesian regression model to evaluate the economic loss resulting from two-ship collisions using ten years’ ship collision data for occurrances in Fujian waters. The model results show that the involvement of passenger/cruise ships could cause the largest increment on economic loss in ship collisions. Interestingly, it is found the involvement of fishing ships could greatly increase the ship collision consequence in terms of economic loss. Results also reveal that the higher economic loss is associated with the collisions in the straits/sea areas, under the strong wind/wave conditions, during nighttime period, and in poor visibility conditions. The impact analysis results highlight that judgment errors play a decisive role in increasing the economic loss as compared with the other two types of human errors: lookout failure and operation errors. The results of this study are useful for policy-makers in proposing efficient strategies to mitigate the economic loss from two-ship collisions. The developed model is also beneficial for insurance companies in determining the appropriate ship insurance rates.
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Li, Jinxin, Hongbo Wang, Zhiying Guan, and Chong Pan. "Distributed Multi-Objective Algorithm for Preventing Multi-Ship Collisions at Sea." Journal of Navigation 73, no. 5 (March 3, 2020): 971–90. http://dx.doi.org/10.1017/s0373463320000053.
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Avoidance of collisions at sea is crucial to navigational safety. In this paper, we use a distributed algorithm to communicate the entire collision avoidance trajectory information for each ship. In each communication, we suggest a new improvement function considering safety and efficiency to identify the avoidance ship in each cycle. Considering the nonlinear collision avoidance trajectory of ships, a new method for calculating the degree of danger using a velocity obstacle algorithm is proposed. Therefore, in each communication, each ship considers the avoidance behaviours of other ships in planning its avoidance trajectory. Additionally, we combine bi-criterion evolution (BCE) and the ant lion optimiser to plan the entire collision avoidance path. Three scenarios are designed to demonstrate the performance of this method. The results show that the proposed method can find a suitable collision-free solution for all ships.
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Ha, Jisang, Myung-Il Roh, and Hye-Won Lee. "Quantitative calculation method of the collision risk for collision avoidance in ship navigation using the CPA and ship domain." Journal of Computational Design and Engineering 8, no. 3 (May 13, 2021): 894–909. http://dx.doi.org/10.1093/jcde/qwab021.
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Abstract Collision risk (CR) assessment is necessary for avoiding collisions with other ships. The CR can be used to make decisions on collision avoidance. In this respect, the ship domain and the closest point of approach (CPA)-based methods have been proposed to assess the CRs. However, the ship domain method is limited in terms of the quantitative calculation of the CR, whereas the CPA-based method does not guarantee reliable collision avoidance. In this study, an improved method is proposed for the quantitative calculation of the CR in ship navigation that combines the advantages of two existing methods. The proposed method calculates the CR using the CPA and defines the ship domain as a critical value of the CR to ensure reliable collision avoidance. In this process, the CR value of another ship on the boundary of the ship domain is calculated as 1, which implies that collision occurs, and the coefficients for the CR calculation are adjusted considering the distance from the ship domain. Furthermore, the manoeuvring performance and the heading angle of the ships are considered in the calculation of the CR. To evaluate the proposed method, it is applied to various examples, including a comparison with previous methods. The results show that the proposed method can be used to obtain a quantitative CR for collision avoidance.
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Lazarowska, Agnieszka. "Safe Ship Control Method with the Use of Ant Colony Optimization." Solid State Phenomena 210 (October 2013): 234–44. http://dx.doi.org/10.4028/www.scientific.net/ssp.210.234.
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Nowadays Integrated Bridge Systems are applied on board a ship to increase safety of navigation. These systems consist of many electronic devices such as radar, ECDIS and autopilot, which aid the deck officer in the process of conducting navigation. Despite that, ship accidents caused by human error still occur. The paper presents new method of safe ship control in collision situations. Ant Colony Optimization is applied to determine safe ship trajectory. Developed algorithm is applicable for situations in restricted waters, where most of collision situations occur. International Regulations for Preventing Collisions at Sea (COLREGs) are taken into consideration in the process of solution construction. The task of collision avoidance at sea is defined as dynamic optimization problem with the use of static and dynamic constraints. Static constraints are represented by lands, canals, shallows, fairways, while other ships constitute dynamic constraints. Described method was implemented in MATLAB programming language. Performed simulation tests results of encounter situations with one target ship as well as with many target vessels are presented. Received solutions confirm successful application of this method to the problem of ships collisions avoidance. Developed algorithm deals also with more complex situations. This new algorithm is planned to be implemented in anti-collision decision support system on board a ship, what would contribute to enhance safety of maritime transport.
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Liu, Xin, Shuwei Ren, Lei Zhang, Wei Shen, and Yubo Tu. "Research on Dynamic Path Planning and Tracking Control for Ship Collision Avoidance." Journal of Physics: Conference Series 2607, no. 1 (October 1, 2023): 012012. http://dx.doi.org/10.1088/1742-6596/2607/1/012012.
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Abstract Ship collisions are prevalent every year, leading to significant maritime traffic accidents. This paper presents research on dynamic path planning and tracking control for ship collision avoidance by integrating ship automatic avoidance technology to address this issue. We conducted a comprehensive study on artificial potential fields, trajectory tracking, and route trajectory tracking in response to the current state of ship collision avoidance and trajectory tracking. The study employed vector decomposition and slider control as research methods to analyze, optimize, and modify ship collision avoidance methods. Additionally, we carried out collision avoidance simulations using MATLAB to verify the stability and safety of ship trajectory tracking under various methods to advance the research on ship collision avoidance and trajectory. The proposed approach has the potential to significantly reduce ship collisions and enhance ship trajectory safety.
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Kim, Kwang-Il, Jung Sik Jeong, and Byung-Gil Lee. "Study on the Analysis of Near-Miss Ship Collisions Using Logistic Regression." Journal of Advanced Computational Intelligence and Intelligent Informatics 21, no. 3 (May 19, 2017): 467–73. http://dx.doi.org/10.20965/jaciii.2017.p0467.
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Generally, risk assessment for a ship collision can be performed by analyzing the trajectories of two ships as they get close to each other. A near-miss collision between ships is an undesired event that did not result in collision, but had a high risk of doing so. Due to the high frequency of these occurrences, many actual accident data samples can be obtained. In this paper, we extract various variables related to near-miss collisions from this data, such as Distance to Closest Point of Approach (DCPA), Time to Closest Point of Approach (TCPA) and Collision Avoidance Variance (CAV). To assess near-miss collision risk, logistic regression analysis is performed by categorizing encounter types based on ship trajectories collected over 4 months in coastal water areas.
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Zhao, Xingya, Yixiong He, Liwen Huang, Junmin Mou, Ke Zhang, and Xiao Liu. "Intelligent Collision Avoidance Method for Ships Based on COLRGEs and Improved Velocity Obstacle Algorithm." Applied Sciences 12, no. 18 (September 6, 2022): 8926. http://dx.doi.org/10.3390/app12188926.
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Collision prevention is critical for navigational safety at sea, which has developed rapidly in the past decade and attracted a lot of attention. In this article, an improved velocity obstacle (IVO) algorithm for intelligent collision avoidance of ocean-going ships is proposed in various operating conditions, taking into count both a ship’s manoeuvrability and Convention on the International Regulations for Preventing Collisions at Sea (COLREGs). An integrated model combines a three-degree-of-freedom manoeuvring model with ship propeller characteristics to provide a precise prediction of ships in various manoeuvring circumstances. In the given case, what is different to present studies, this improved algorithm allows for decision-making in two ways: altering course and changing speed. The proposed technique is demonstrated in a variety of scenarios through simulation. The findings reveal that collision-avoidance decision-making can intelligently avoid collisions with the target ships (TSs) in multi-ship situations.
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Wang, Xiaoyuan, Lulu Zhang, Gang Wang, Quanzheng Wang, and Guowen He. "Modeling of relative collision risk based on the ships group situation." Journal of Intelligent & Fuzzy Systems 41, no. 6 (December 16, 2021): 7137–50. http://dx.doi.org/10.3233/jifs-211025.
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The collision risk of ships is a fuzzy concept, which is the measurement of the likelihood of a collision between ships. Most of existed studies on the risk of multi-ship collision are based on the assessment of two-ship collision risk, and collision risk between the target ship and each interfering ship is calculated respectively, to determine the key avoidance ship. This method is far from the actual situation and has some defects. In open waters, it is of certain reference value when there are fewer ships, but in busy waters, it cannot well represent the risk degree of the target ship, since it lacks the assessment of the overall risk of the perceived area of the target ship. Based on analysis of complexity of ships group situation, the concept of relative domain was put forward and the model was constructed. On this basis, the relative collision risk was proposed, and the corresponding model was obtained, so as to realize risk assessment. Through the combination of real ship and simulation experiments, the variation trend, stability and sensitivity of the model were verified. The results showed that risk degree of the environment of ships in open and busy waters could be well assessed, and good references for decision-making process of ships collision avoidance could be provided.
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Zhou, Lingyu, Huayong Li, Jun Wei, Xingxu Pu, Akim D. Mahunon, and Liqiang Jiang. "Design and Simulation Analysis of a New Type of Assembled UHPC Collision Avoidance." Applied Sciences 10, no. 13 (June 30, 2020): 4555. http://dx.doi.org/10.3390/app10134555.
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Ship-bridge collisions are one of the most common types of accidents, and bridge anti-ship collision devices are of great importance for bridge protection. First, a new type of assembled ultra-high performance concrete (UHPC) collision avoidance is proposed in this paper. The main components of the device are double-deck, two-way, densely reinforced ultra-high performance concrete floating boxes that are connected by high-strength bolts to form the whole structure and are equipped with steel supporting elements to form a collision energy dissipation device. The device is self-floating in water, is strongly energy absorbing due to plastic deformation, has a high degree of toughness, is corrosion resistant, and so on. This device also benefits from modular manufacturing, efficient installation, and easy replacement of damaged parts. Then, in this paper, the main parameters of the new collision avoidance, such as the material of the internal supporting elements, the wall thickness of the floating box, and the reinforcement ratio of the floating box, are optimized. Finally, a performance analysis and evaluation of the UHPC collision avoidance for the Honghe Bridge in Zhuhai City are carried out by using LS-DYNA program. The numerical results show that the new collision avoidance has significant advantages in reducing the ship–bridge collision force, prolonging the ship–bridge collision time, and protecting the ship. The results show that the assembled UHPC collision avoidance system is very effective for protecting ships and bridges in the event of a ship–bridge collision.
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Li, Jinxin, Hongbo Wang, Wei Zhao, and Yuanyuan Xue. "Ship’s Trajectory Planning Based on Improved Multiobjective Algorithm for Collision Avoidance." Journal of Advanced Transportation 2019 (April 9, 2019): 1–12. http://dx.doi.org/10.1155/2019/4068783.
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With vigorous development of the maritime trade, many intelligent algorithms have been proposed to avoid collisions due to resulting casualties and increased costs. According to the international regulations for preventing collisions at sea (COLREGs) and the self-evolution ability of the intelligent algorithm, the collision avoidance trajectory can be more consistent with the requirements of reality and maritime personnel. In this paper, the optimization of ship collision avoidance strategies is realized by both an improved multiobjective optimization algorithm NSGA-II and the ship domain under the condition of a wide sea area without any external disturbances. By balancing the safety and economy of ship collision avoidance, the avoidance angle and the time to the action point are used as the variables encoded by the algorithm, and the fuzzy ship domain is used to calculate the collision avoidance risk to achieve collision avoidance. The simulation results show that the proposed method can optimize the ship collision avoidance strategy and provide a reasonable scheme for ship navigation.
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Luo, Fangwei, and Jie Yang. "Ship collision avoidance control based on improved velocity obstacle method." Journal of Physics: Conference Series 2558, no. 1 (August 1, 2023): 012041. http://dx.doi.org/10.1088/1742-6596/2558/1/012041.
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Abstract The velocity obstacle method has extensive research in collision avoidance, which uses circles to represent robots or ships to find a collision-free velocity. To better describe the motion characteristics of ships, an improved velocity obstacle method based on elliptical ship domain is proposed in this paper. In the previous research on collision avoidance, the ship domains of the own ship and the target ship are seldom considered at the same time. This paper considers the ship domains of the own ship and the target ship at the same time and judges whether the ship domains of the two ships overlap based on the generalized characteristic polynomial. The heading angle is discretized to construct the velocity obstacle (VO) by calculating the collision velocity at different heading angles. Velocities on the boundaries of the velocity obstacle are used to find an optimal heading angle. The algorithm is tested in different encounter situations and successfully realizes collision avoidance.
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Yu, Jiagen, Zhengjiang Liu, and Xianku Zhang. "DCA-Based Collision Avoidance Path Planning for Marine Vehicles in Presence of the Multi-Ship Encounter Situation." Journal of Marine Science and Engineering 10, no. 4 (April 12, 2022): 529. http://dx.doi.org/10.3390/jmse10040529.
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The problem of ship collision avoidance path planning is one of the key problems in the ship motion control field. Aiming at the high computational time problem of path planning in multi-ship encounter situations and the impact of the target ship’s action changes on path planning, this paper proposes a dynamic path-planning method based on dynamic cluster analysis (DCA), which is used to dynamically cluster target ships with similar attributes into a group ship, reducing the number of calculated targets and improving the efficiency of path planning. Taking into full consideration the action requirements of the International Regulations for Preventing Collisions at Sea (COLREGs), the course alteration action matrix (CAAM) for collision avoidance is established to limit the space of candidate solutions. On the basis of the rapid optimization capability of the deterministic optimization algorithm (DOA), a dynamic monitoring mechanism is introduced to establish a multi-ship encounter intelligent collision avoidance decision-making model that meets the needs of real-time collision avoidance. The simulation results showed that the method can obtain a dynamic collision avoidance path that is safe and feasible.
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Yoo, Yunja, and Jin-Suk Lee. "Collision Risk Assessment Support System for MASS RO and VTSO Support in Multi-Ship Environment of Vessel Traffic Service Area." Journal of Marine Science and Engineering 9, no. 10 (October 18, 2021): 1143. http://dx.doi.org/10.3390/jmse9101143.
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The discussions by the International Maritime Organization for the introduction of a maritime autonomous surface ship (MASS) began in earnest. At the 27th ENAV meeting, the International Association of Marine Aids to Navigation and Lighthouse Authorities proposed the “sharing of a common operating picture for situational awareness of the waterway within vessel traffic service (VTS) environment” when developing a system to support MASS operation. Marine accidents caused by collisions on waterways still account for a high percentage of ship accidents that occur at sea, and many studies have investigated the risk of collision between ships. Collision risk assessment was primarily conducted in ship domain-based safety areas. This study evaluates the collision risk using the ship domain derived by the VTS operator (VTSO) and proposes a real-time collision risk assessment support system to improve the situational awareness of VTSOs and MASS remote operators (MASS ROs) regarding near-collision situations occurring in local waters. To evaluate the validity of the proposed system, a risk analysis was performed on near-collision scenarios at Busan Port. The results show that the distance to the closest point of approach (CPA), time to the CPA, and inter-ship distance converged within 0.5 nautical miles, 10 min, and 3 nautical miles, respectively.
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Zheng, Yisong, Xiuguo Zhang, Zijing Shang, Siyu Guo, and Yiquan Du. "A Decision-Making Method for Ship Collision Avoidance Based on Improved Cultural Particle Swarm." Journal of Advanced Transportation 2021 (January 15, 2021): 1–31. http://dx.doi.org/10.1155/2021/8898507.
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In the process of ship collision avoidance decision making, steering collision avoidance is the most frequently adopted collision avoidance method. In order to obtain an effective and reasonable steering angle, this paper proposes a decision-making method for ship collision avoidance based on improved cultural particle swarm. Firstly, the ship steering angle direction is to be determined. In this stage, the Kalman filter is used to predict the ship’s trajectory. According to the prediction parameters, the collision risk index of the ship is calculated and the situation with the most dangerous ship is judged. Then, the steering angle direction of the ship is determined by considering the Convention on the International Regulations for Preventing Collisions at Sea (COLREGs). Secondly, the ship steering angle is to be calculated. In this stage, the cultural particle swarm optimization algorithm is improved by introducing the index of population premature convergence degree to adaptively adjust the inertia weight of the cultural particle swarm so as to avoid the algorithm falling into premature convergence state. The improved cultural particle swarm optimization algorithm is used to find the optimal steering angle within the range of the steering angle direction. Compared with other evolutionary algorithms, the improved cultural particle swarm optimization algorithm has better global convergence. The convergence speed and stability are also significantly improved. Thirdly, the ship steering angle direction decision method in the first stage and the ship steering angle decision method in the second stage are integrated into the electronic chart platform to verify the effectiveness of the decision-making method of ship collision avoidance presented in this paper. Results show that the proposed approach can automatically realize collision avoidance from all other ships and it has an important practical application value.
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Wu, Qing, Tengfei Wang, Mihai A. Diaconeasa, Ali Mosleh, and Yang Wang. "A Comparative Assessment of Collision Risk of Manned and Unmanned Vessels." Journal of Marine Science and Engineering 8, no. 11 (October 29, 2020): 852. http://dx.doi.org/10.3390/jmse8110852.
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It is expected that the prototypes of unmanned merchant ships will be deployed in the next few years. However, there is no specific research on whether the introduction of unmanned ships will reduce the risk of ship collision accidents in which communication between vessels is critical. This work constitutes an attempt to bridge the gap identified above by applying the Hybrid Causal Logic (HCL) methodology to model general-level collision scenarios of unmanned ships. The HCL methodology has been selected for its proven applicability to risk assessments, even when empirical data may be insufficient. Collision scenarios involving unmanned ships have been created in which manned ships of the conventional collision scenario HCL model are replaced with unmanned ships. Then, collision scenarios capturing the interactions between a manned ship and an unmanned ship were modeled. By comparing the qualitative and quantitative results of the different scenarios, we can see that the introduction of unmanned ships may effectively reduce the occurrence of ship collision accidents.
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Zhang, Ke, Liwen Huang, Yixiong He, Liang Zhang, Weiguo Huang, Cheng Xie, and Guozhu Hao. "Collision Avoidance Method for Autonomous Ships Based on Modified Velocity Obstacle and Collision Risk Index." Journal of Advanced Transportation 2022 (October 8, 2022): 1–22. http://dx.doi.org/10.1155/2022/1534815.
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A novel real-time collision avoidance method for autonomous ships based on modified velocity obstacle (VO) algorithm and grey cloud model is proposed. A typical VO algorithm is used to judge whether there is a collision risk for ships in the potential collision area (PCA). Then, in order to quantify the collision risk of ships in different encounter situations within the PCA and trigger a prompt warning of danger of collision, this study sets up a novel collision risk assessment method based on asymmetric grey cloud model (AGC). It can effectively consider the randomness, ambiguity, and incompleteness of the information in the ship collision risk evaluation process. Moreover, reachable collision-free velocity sets under different encounter situations and optimal steering angle model are constructed. A real-time collision avoidance method based on modified VO algorithm and manoeuvring motion characteristics of vessels is put forward. In this model, various constraints are considered including the International Regulations for Preventing Collisions at Sea (COLREGs), ship manoeuvrability, and ordinary practice of seaman. Finally, several case studies are carried out to verify the performance and reliability of the collision avoidance model. The results show that the proposed method can not only effectively identify and quantify the collision risk in real-time but also offer proper collision-free solutions for autonomous ships.
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Lu, Chao-Wei, Chao-Kuang Hsueh, Yung-Lin Chuang, Ching-Ming Lai, and Fuh-Shyong Yang. "Marine Collision Avoidance Route Planning Model for MASS Based on Domain-Based Predicted Area of Danger." Journal of Marine Science and Engineering 11, no. 9 (September 1, 2023): 1724. http://dx.doi.org/10.3390/jmse11091724.
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When the own ship encounters target ships in a close-quarter situation, an officer on watch needs to safely and timely alter the course of the vessel to avoid a collision. If ECDIS can automatically collect the navigation parameters and plot areas of collision as quasi-static obstruction areas, it will be much easier for seafarers to implement effective route planning. Hence, this study focuses on developing the MCARP model as a theoretical concept based on the DPAD model and LCD model. By operating the MCARP using ArcGIS, DPADs and several effective collision avoidance routes can be generated and imported into ECDIS based on AIS information at large scales and ample time. The graphic overlay of DPADs and effective routes on ECDIS can serve as a collision avoidance strategy reference for the personnel controlling maritime autonomous surface ships. Finally, different ships encountering situations were input into a Transas navigational simulator. The simulation results showed that own ship could avoid collisions with multiple target ships at distances larger than the preset collision avoidance distances, which also indicated that MCARP is practically feasible.
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Guan, Wei, Ming-yang Zhao, Cheng-bao Zhang, and Zhao-yong Xi. "Generalized Behavior Decision-Making Model for Ship Collision Avoidance via Reinforcement Learning Method." Journal of Marine Science and Engineering 11, no. 2 (January 25, 2023): 273. http://dx.doi.org/10.3390/jmse11020273.
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Due to the increasing number of transportation vessels, marine traffic has become more congested. According to the statistics, 89% to 95% of maritime accidents are related to human factors. In order to reduce marine incidents, ship automatic collision avoidance has become one of the most important research issues in the field of ocean engineering. A generalized behavior decision-making (GBDM) model, trained via a reinforcement learning (RL) algorithm, is proposed in this paper, and it can be used for ship autonomous driving in multi-ship encounter situations. Firstly, the obstacle zone by target (OZT) is used to calculate the area of future collisions based on the dynamic information of ships. Meanwhile, a virtual sensor called a grid sensor is taken as the input of the observation state. Then, International Regulations for Preventing Collision at Sea (COLREGs) is introduced into the reward function to make the decision-making fully comply with COLREGs. Different from the previous RL-based collision avoidance model, the interaction between the ship and the environment only works in the collision avoidance decision-making stage. Finally, 60 complex multi-ship encounter scenarios clustered by the COLREGs are taken as the ship’s GBDM model training environments. The simulation results show that the proposed GBDM model and training method has flexible scalability in solving the multi-ship collision avoidance problem complying with COLREGs in different scenarios.
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Vukša, Srđan, Pero Vidan, Mihaela Bukljaš, and Stjepan Pavić. "Research on Ship Collision Probability Model Based on Monte Carlo Simulation and Bi-LSTM." Journal of Marine Science and Engineering 10, no. 8 (August 15, 2022): 1124. http://dx.doi.org/10.3390/jmse10081124.
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The efficiency and safety of maritime traffic in a given area can be measured by analyzing traffic density and ship collision probability. Maritime traffic density is the number of ships passing through a given area in a given period of time. It can be measured using vessel tracking systems, such as the Automatic Identification System (AIS). The information provided by AIS is real-time data designed to improve maritime safety. However, the AIS data can also be used for scientific research purposes to improve maritime safety by developing predictive models for collisions in a research area. This article proposes a ship collision probability estimation model based on Monte Carlo simulation (MC) and bidirectional long short-term memory neural network (Bi-LSTM) for the maritime region of Split. The proposed model includes the processing of AIS data, the verification of AIS data, the determination of ports and ship routes, MC and the collision probability, the Bi-LSTM learning process based on MC, the ship collision probability for new or existing routes, and the traffic density. The results of MC, i.e., traffic/vessel route and density, and collision probability for the study area can be used for Bi-LSTM training with the aim of estimating ship collision probability. This article presents the first part of research that includes MC in detail, followed by a preliminary result based on one day of processed AIS data used to simulate MC and propose a model architecture that implements Bi-LSTM for ship collision probability estimation.
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Zhang, Jiping, and Yonghe Xie. "Collision Numerical Simulation Research of River-Sea Ship." Open Mechanical Engineering Journal 8, no. 1 (December 31, 2014): 885–91. http://dx.doi.org/10.2174/1874155x01408010885.
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Collision simulation of river-sea ship is accomplished based on nonlinear finite element method. Firstly, we discuss the development of collision analysis methods including theoretical methods, empirical formula method, experimental techniques and numerical analysis methods, and introduce the Central Difference Method adopted in the collision simulation. Then, model of ship structure and rigid sphere structure are established, through taking into account the suitability for collision simulation of ship structure, we adopt Cowper-Symonds constitutive equation as the material characteristics and maximum equivalent plasticity as the failure criterion. Finally, collision-resistant performance of riversea ship is simulated through collisions between ship structure and rigid sphere structure at cargo centre and cargo end. Simulation results indicate that damage extent of river-sea ship depends on collision speed primarily, with the increase of collision speed, collision force increases accordingly, local structure invalidates and local damage occurs. Comparison between collision at cargo centre and collision at cargo end shows that the improvement of structural rigidity is effective to increase collision-resistant performance. Such, it is necessary to make evaluation on collision-resistant performance and strengthen the structures easily collided for ship designed according to specification, especially for the ship with single side structure. The research is of great guiding significance to hull structure design, and it is beneficial to increase security of the same type ship.
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Zhang, Jie, and Yingjun Zhang. "A Novel Ship-Ship Distance Model in Restricted Channel via Gaussian-TRR Identification." Mathematical Problems in Engineering 2021 (March 1, 2021): 1–19. http://dx.doi.org/10.1155/2021/6626850.
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Very large ships are crucial cargo ships that are relatively difficult to manoeuvre, and ship-ship distance is a vital manoeuvring parameter in restricted channel. To ensure ship safety and improve scheduling efficiency, this study established a ship-ship distance model in restricted channel by ship manoeuvring motion simulation, collision detection, and identification modelling. Firstly, the ship manoeuvring model calculated the forces and moments of ship-ship interaction and ship-bank interaction. Then, the collision detection was applied to calculate the intersection area of ship collision. Secondly, the discrete numerical simulation approach was employed with varying speed and distance, and the intersection area was counted. Finally, the 3D Gaussian models of encountering and overtaking were identified by the trust-region-reflective (TRR) algorithm, and ship-ship distance and prohibited zone were proposed. The results show that the minimum ship-ship distance for encountering and overtaking is 1.50 and 2.4 ship beam, respectively, which is consistent with Japan’s standard. The numerical results revealed that the prohibited zone is an elliptical shape. The ship-ship distance and prohibited zone serve as ship safety domain for collision avoidance during harbor approaching.
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Zhen, Rong, Ziqiang Shi, Zheping Shao, and Jialun Liu. "A novel regional collision risk assessment method considering aggregation density under multi-ship encounter situations." Journal of Navigation 75, no. 1 (November 19, 2021): 76–94. http://dx.doi.org/10.1017/s0373463321000849.
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AbstractThe regional ship collision risk assessment for multiple ships in restricted waters is of great significance to the early warning of ship collision risk and the intelligent supervision of maritime traffic. Given the existed method of regional ship collision risk assessment without considering the impact of ship aggregation density, this paper proposes a novel regional ship collision risk assessment method that considers the aggregation density (AD) of the clusters of encounter ships (CES) for intelligent surveillance and navigation. The effectiveness of the proposed method has been examined by the experimental case study in the waters of Xiamen, China, and analysis has been compared with other existed studies to show the advantages of the new proposed algorithm. The results show that the study method can more intuitively and effectively quantify the temporal and spatial distribution of regional collision risks in the restricted sea area. The proposed method can improve the efficiency of traffic management when monitoring the ship collision risks in macroscopic view, and assist the safety of manned and unmanned ship navigation.
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Zhang, Guangyu, Yan Wang, Jian Liu, Wei Cai, and Hongbo Wang. "Collision-Avoidance Decision System for Inland Ships Based on Velocity Obstacle Algorithms." Journal of Marine Science and Engineering 10, no. 6 (June 14, 2022): 814. http://dx.doi.org/10.3390/jmse10060814.
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Due to the complex hydrology and narrow channels of inland rivers, ship collision accidents occur frequently. The traditional collision-avoidance algorithms are often aimed at sea areas, and not often at inland rivers. To solve the problem of inland-ship collision avoidance, this paper proposes an inland-ship collision-avoidance decision system based on the velocity obstacle algorithm. The system is designed to assist ships in achieving independent collision-avoidance operations under the limitation of maneuverability while meeting inland-ship collision-avoidance regulations. First, the paper improves the Maneuvering Modeling Group (MMG) model suitable for inland rivers. Then, it improves velocity obstacle algorithms based on the dynamic ship domain, which can deal with different obstacles and three encounter situations (head-on, crossing, and overtaking situations). In addition, this paper proposes a method to deal with close-quarters situations. Finally, the simulation environment built by MATLAB software is used to simulate the collision avoidance of inland ships against different obstacles under different situations with a decision-making time of less than 0.1 s. Through the analysis of the simulation results, the effectiveness and practicability of the system are verified, which can provide reasonable collision-avoidance decisions for inland ships.
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Yang, Shujie, and Wei Sun. "Effective Ship Domains Considering Ship Encounter Situations and Speeds." Journal of Physics: Conference Series 2219, no. 1 (April 1, 2022): 012031. http://dx.doi.org/10.1088/1742-6596/2219/1/012031.
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Abstract Ship domain is an important concept in assessing navigation situation and planning collision avoidance manoeuvres of a ship. For purpose of improving the precision and adaptability of the ship domains, effective ship domains are proposed for ships with different speeds in a variety of encounter situations in this work. Firstly, the COLREGs-based division of encounter types and corresponding collision avoidance actions are further optimized. Therefore, the problem of unclear division of responsibilities caused by the intersection of relative position and relative heading is resolved. On this basis, ship domains are determined by the encounter situations and the target ship’s speed. More specifically, the ship domain is approximated to a circle, and the dependence of the domain size on the encounter situation and the target ship’s speed has been analysed and described, that enable us to determine effective ships domains for ships varying in speeds and encounter situations. The simulation results show that ships can make effective collision-avoidance actions in different encounter scenarios based on the optimized COLREGs-based division of encounter types and effective ship domains.
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Zhai, Pengyu, Yingjun Zhang, and Wang Shaobo. "Intelligent Ship Collision Avoidance Algorithm Based on DDQN with Prioritized Experience Replay under COLREGs." Journal of Marine Science and Engineering 10, no. 5 (April 26, 2022): 585. http://dx.doi.org/10.3390/jmse10050585.
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Ship collisions often result in huge losses of life, cargo and ships, as well as serious pollution of the water environment. Meanwhile, it is estimated that between 75% and 86% of maritime accidents are related to human factors. Thus, it is necessary to enhance the intelligence of ships to partially or fully replace the traditional piloting mode and eventually achieve autonomous collision avoidance to reduce the influence of human factors. In this paper, we propose a multi-ship automatic collision avoidance method based on a double deep Q network (DDQN) with prioritized experience replay. Firstly, we vectorize the predicted hazardous areas as the observation states of the agent so that similar ship encounter scenarios can be clustered and the input dimension of the neural network can be fixed. The reward function is designed based on the International Regulations for Preventing Collision at Sea (COLREGs) and human experience. Different from the architecture of previous collision avoidance methods based on deep reinforcement learning (DRL), in this paper, the interaction between the agent and the environment occurs only in the collision avoidance decision-making phase, which greatly reduces the number of state transitions in the Markov decision process (MDP). The prioritized experience replay method is also used to make the model converge more quickly. Finally, 19 single-vessel collision avoidance scenarios were constructed based on the encounter situations classified by the COLREGs, which were arranged and combined as the training set for the agent. The effectiveness of the proposed method in close-quarters situation was verified using the Imazu problem. The simulation results show that the method can achieve multi-ship collision avoidance in crowded waters, and the decisions generated by this method conform to the COLREGs and are close to the level of human ship handling.
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Zhai, Pengyu, Yingjun Zhang, and Wang Shaobo. "Intelligent Ship Collision Avoidance Algorithm Based on DDQN with Prioritized Experience Replay under COLREGs." Journal of Marine Science and Engineering 10, no. 5 (April 26, 2022): 585. http://dx.doi.org/10.3390/jmse10050585.
Full textAbstract:
Ship collisions often result in huge losses of life, cargo and ships, as well as serious pollution of the water environment. Meanwhile, it is estimated that between 75% and 86% of maritime accidents are related to human factors. Thus, it is necessary to enhance the intelligence of ships to partially or fully replace the traditional piloting mode and eventually achieve autonomous collision avoidance to reduce the influence of human factors. In this paper, we propose a multi-ship automatic collision avoidance method based on a double deep Q network (DDQN) with prioritized experience replay. Firstly, we vectorize the predicted hazardous areas as the observation states of the agent so that similar ship encounter scenarios can be clustered and the input dimension of the neural network can be fixed. The reward function is designed based on the International Regulations for Preventing Collision at Sea (COLREGs) and human experience. Different from the architecture of previous collision avoidance methods based on deep reinforcement learning (DRL), in this paper, the interaction between the agent and the environment occurs only in the collision avoidance decision-making phase, which greatly reduces the number of state transitions in the Markov decision process (MDP). The prioritized experience replay method is also used to make the model converge more quickly. Finally, 19 single-vessel collision avoidance scenarios were constructed based on the encounter situations classified by the COLREGs, which were arranged and combined as the training set for the agent. The effectiveness of the proposed method in close-quarters situation was verified using the Imazu problem. The simulation results show that the method can achieve multi-ship collision avoidance in crowded waters, and the decisions generated by this method conform to the COLREGs and are close to the level of human ship handling.
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Zhai, Pengyu, Yingjun Zhang, and Wang Shaobo. "Intelligent Ship Collision Avoidance Algorithm Based on DDQN with Prioritized Experience Replay under COLREGs." Journal of Marine Science and Engineering 10, no. 5 (April 26, 2022): 585. http://dx.doi.org/10.3390/jmse10050585.
Full textAbstract:
Ship collisions often result in huge losses of life, cargo and ships, as well as serious pollution of the water environment. Meanwhile, it is estimated that between 75% and 86% of maritime accidents are related to human factors. Thus, it is necessary to enhance the intelligence of ships to partially or fully replace the traditional piloting mode and eventually achieve autonomous collision avoidance to reduce the influence of human factors. In this paper, we propose a multi-ship automatic collision avoidance method based on a double deep Q network (DDQN) with prioritized experience replay. Firstly, we vectorize the predicted hazardous areas as the observation states of the agent so that similar ship encounter scenarios can be clustered and the input dimension of the neural network can be fixed. The reward function is designed based on the International Regulations for Preventing Collision at Sea (COLREGs) and human experience. Different from the architecture of previous collision avoidance methods based on deep reinforcement learning (DRL), in this paper, the interaction between the agent and the environment occurs only in the collision avoidance decision-making phase, which greatly reduces the number of state transitions in the Markov decision process (MDP). The prioritized experience replay method is also used to make the model converge more quickly. Finally, 19 single-vessel collision avoidance scenarios were constructed based on the encounter situations classified by the COLREGs, which were arranged and combined as the training set for the agent. The effectiveness of the proposed method in close-quarters situation was verified using the Imazu problem. The simulation results show that the method can achieve multi-ship collision avoidance in crowded waters, and the decisions generated by this method conform to the COLREGs and are close to the level of human ship handling.
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Čorić, Mirko, Sadko Mandžuka, Anita Gudelj, and Zvonimir Lušić. "Quantitative Ship Collision Frequency Estimation Models: A Review." Journal of Marine Science and Engineering 9, no. 5 (May 16, 2021): 533. http://dx.doi.org/10.3390/jmse9050533.
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Ship collisions are one of the most common types of maritime accidents. Assessing the frequency and probability of ship collisions is of great importance as it provides a cost-effective and practical way to mitigate risk. In this paper, we present a review of quantitative ship collision frequency estimation models for waterway risk assessment, accompanied by a classification of the models and a description of their main modelling characteristics. Models addressing the macroscopic perspective in the estimation of ship collision frequency on waterways are reviewed in this paper with a total of 29 models. We extend the existing classification methodology and group the collected models accordingly. Special attention is given to the criteria used to detect potential ship collision candidates, as well as to causation probability and the correlation of models with real ship collision statistics. Limitations of the existing models and future improvement possibilities are discussed. The paper can be used as a guide to understanding current achievements in this field.
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Li, Weifeng, Lufeng Zhong, Yang Xu, and Guoyou Shi. "Collision Risk Index Calculation Based on an Improved Ship Domain Model." Journal of Marine Science and Engineering 10, no. 12 (December 16, 2022): 2016. http://dx.doi.org/10.3390/jmse10122016.
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The traditional ship collision risk index model based on the distance at the closest point of approach (DCPA) and the time to the closest point of approach (TCPA) is insufficient for estimating ship collision risk and planning collision avoidance operations. This paper constructs an elliptical, dynamic ship domain that changes with ship speed and maneuverability parameters to overcome subjective human factors. Based on the constructed domain model, the concept of the ship domain proximity factor is introduced to improve the ship collision risk model based on DCPA and TCPA, and a risk calculation function model that considers the safety of ship navigation is constructed. The numerical calculation of the improved collision risk index calculation model confirms that the enhanced model has a higher rate of identification of risk between ships. The model is more compatible with the requirements of ship navigation decision-making and can provide theoretical support and a technical basis for research on ship collision avoidance decision-making.
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Wickens, Christopher D., Adam Williams, Benjamin A. Clegg, and C. A. P. Smith. "Nautical Collision Avoidance." Human Factors: The Journal of the Human Factors and Ergonomics Society 62, no. 8 (September 18, 2019): 1304–21. http://dx.doi.org/10.1177/0018720819871409.
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Objective Experimentally investigate maneuver decision preferences in navigating ships to avoid a collision. How is safety (collision avoidance) balanced against efficiency (deviation from path and delay) and rules of the road under conditions of both trajectory certainty and uncertainty. Background Human decision error is a prominent factor in nautical collisions, but the multiple factors of geometry of collisions and role of uncertainty have been little studied in empirical human factors literature. Approach Eighty-seven Mechanical Turk participants performed in a lower fidelity ship control simulation, depicting ownship and a cargo ship hazard on collision or near-collision trajectories of various conflict geometries, while controlling heading and speed with the sluggish relative dynamics. Experiment 1 involved the hazard on a straight trajectory. In Experiment 2, the hazard could turn on unpredictable trials. Participants were rewarded for efficiency and penalized for collisions or close passes. Results Participants made few collisions, but did so more often when on a collision path. They sometimes violated the instructed rules of the road by maneuvering in front of the hazard ship’s path. They preferred speed control to heading control. Performance degraded in conditions of uncertainty. Conclusion Data reveal an understanding of maneuver decisions and conditions that affect the balance between safety and efficiency. Application The simulation and data highlight the degrading role of uncertainty and provide a foundation upon which more complex questions can be asked, asked of more trained navigators, and decision support tools examined.
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Sviličić, Šimun, and Smiljko Rudan. "Modelling Manoeuvrability in the Context of Ship Collision Analysis Using Non-Linear FEM." Journal of Marine Science and Engineering 11, no. 3 (February 25, 2023): 497. http://dx.doi.org/10.3390/jmse11030497.
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Ship collisions are rare events that may have a significant impact on the safety of people, ships, and other marine structures, as well as on the environment. Because of this, they are extensively studied but events that just precede collision are often overlooked. To rationally assess collision risks and consequences, a ship’s trajectory, and consequently the velocity and collision angle, should be known. One way to achieve this is through accurate modelling of ship manoeuvrability in collision analysis using non-linear FEM (NFEM). The Abkowitz manoeuvring model is implemented in the LS-Dyna software code and is therefore coupled with FEM calculations. Hydrodynamic forces are calculated in each time step of the LS-Dyna calculation and added to the FE model continuously through calculation. The accuracy of the calculations depends on the choice of and values of hydrodynamic derivatives from the Abkowitz model. Abkowitz’s model derives hydrodynamic forces in the Taylor expansion series to provide hydrodynamic derivatives. The application of the procedure is sensitive on higher-order Taylor series members. This article reviews different sets of hydrodynamic derivatives available for the KVLCC2 ship. Each of them is incorporated into the LS-Dyna NFEM solver by a user-made Fortran subroutine, with standard Zigzag and turning manoeuvres simulated and results compared with the experimental tests. As a result, the optimal selection of hydrodynamic derivatives is determined, laying a foundation for assessing the risk of ship collision due to different ship manoeuvres prior to the collision itself.
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Engler, Evelin, Paweł Banyś, Hans-Georg Engler, Michael Baldauf, and Frank Torres. "Evaluation of PNT Error Limits Using Real World Close Encounters from AIS Data." Journal of Marine Science and Engineering 9, no. 2 (February 1, 2021): 149. http://dx.doi.org/10.3390/jmse9020149.
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Collision avoidance is one of the main tasks on board ships to ensure safety at sea. To comply with this requirement, the direct ship environment, which is often modelled as the ship’s domain, has to be kept free of other vessels and objects. This paper addresses the question to which extent inaccuracies in position (P), navigation (N), and timing (T) data impact the reliability of collision avoidance. Employing a simplified model of the ship domain, the determined error bounds are used to derive requirements for ship-side PNT data provision. For this purpose, vessel traffic data obtained in the western Baltic Sea based on the automatic identification system (AIS) is analysed to extract all close encounters between ships considered as real-world traffic situations with a potential risk of collision. This study assumes that in these situations, erroneous data can lead to an incorrect assessment of the situation with regard to existing collision risks. The size of the error determines whether collisions are detected, spatially incorrectly assigned, or not detected. Therefore, the non-recognition of collision risks ultimately determines the limits of tolerable errors in the PNT data. The results indicate that under certain conditions, the probability of non-recognition of existing collision risks can reach non-negligible values, e.g., more than 1%, even though position accuracies are better than 10 m.
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Yang, Xiao, and Qilong Han. "Improved DQN for Dynamic Obstacle Avoidance and Ship Path Planning." Algorithms 16, no. 5 (April 25, 2023): 220. http://dx.doi.org/10.3390/a16050220.
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The avoidance of collisions among ships requires addressing various factors such as perception, decision-making, and control. These factors pose many challenges for autonomous collision avoidance. Traditional collision avoidance methods have encountered significant difficulties when used in autonomous collision avoidance. They are challenged to cope with the changing environment and harsh motion constraints. In the actual navigation of ships, it is necessary to carry out decision-making and control under the constraints of ship manipulation and risk. From the implementation process perspective, it is a typical sequential anthropomorphic decision-making problem. In order to solve the sequential decision problem, this paper improves DQN by setting a priority for sample collection and adopting non-uniform sampling, and it is applied to realize the intelligent collision avoidance of ships. It also verifies the performance of the algorithm in the simulation environment.
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Kim, Inchul. "Systematization of Legal Procedures for Collision Avoidance between a Fully Autonomous Ship and a Traditional Manned Ship." Journal of Marine Science and Engineering 11, no. 10 (September 22, 2023): 1850. http://dx.doi.org/10.3390/jmse11101850.
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Discussions of autonomous ships are actively being conducted in the industry and by the International Maritime Organization (IMO). In addition, it is anticipated that a significant number of autonomous ships will be operational at sea soon, as a trial run of autonomous ships is underway. Fully autonomous ships will operate based on pre-programmed algorithms to prevent collisions, eliminating the need for onboard navigators or remote operators onshore. Most collision avoidance algorithms are typically based on an engineering approach that predicts the future movement of an approaching ship by observing its vector. However, it is worth noting that even if fully autonomous ships navigate at sea, the majority of ships encountered are still operated by humans. These ships adhere to the Convention on the International Regulations for Preventing Collisions at Sea (COLREG). Therefore, even fully autonomous ships can effectively and legally avoid approaching ships only when they are steered in compliance with the COLREG. However, it has rarely been addressed which procedures should be followed to determine the legally correct action in various situations where fully autonomous ships encounter traditional manned ships. Therefore, this study is divided into two parts. First, a decision-making tree is presented, as simply as possible, to determine the legally correct collision avoidance action according to the COLREG. Secondly, a quantitative analysis is presented for qualitative expressions such as “narrow channel”, “restricted visibility”, and “best aid to avoid collision”. This review will help fully autonomous ships determine legitimate collision avoidance actions and operate safely in seas where human-operated ships are sailing. However, for autonomous ships, the “Trolley problem” and issues related to decision-making for collision avoidance through communication with other ships are left as future challenges.
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Shi, Jiahui, and Zhengjiang Liu. "Track Pairs Collision Detection with Applications to Ship Collision Risk Assessment." Journal of Marine Science and Engineering 10, no. 2 (February 6, 2022): 216. http://dx.doi.org/10.3390/jmse10020216.
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The port waterway network plays an important role in the organization and management of port ship traffic. Due to limited ship operations, conflicts, congestion, and safety issues often arise in port waters. Conflicts between ships can be predicted by collision detection between ships. A novel collision detection algorithm for trajectory pairs is proposed by introducing variable time interval variables. In addition, to improve the overall accuracy of trajectory compression and reduce redundant calculation in collision detection, a multi-factor Douglas-Peucker algorithm adapted to ship trajectory compression is proposed with the consideration of speed and turn constraints. The maximum speed difference of the algorithm is increased by 1.5–2.5%, and the average speed difference increased by 2.0–4.5%. Based on the method mentioned above, the risk assessment framework of maritime collision is established and the risk situation of the waters near Ningbo Zhoushan Port is evaluated and analyzed by using ship historical track data.
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Zhang, Weibin, Cole Kopca, Jinjun Tang, Dongfang Ma, and Yinhai Wang. "A Systematic Approach for Collision Risk Analysis based on AIS Data." Journal of Navigation 70, no. 5 (May 24, 2017): 1117–32. http://dx.doi.org/10.1017/s0373463317000212.
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Ship collision risk is an important aspect of ship navigation safety. A systematic method to assess collision risk by monitoring parameter states continually is necessary and has proven effective. Another important factor in risk assessment is ship size, but the effect of the size of ship pairs has not been considered properly in many previous studies. This research utilises a systematic perspective to study collision risk of near-misses in ship-ship encounters. This fills a secondary research gap where previous risk assessments only investigated near-misses from the perspective of a single vessel. Following this proposed approach, ship pair encounter states can be continually tracked. Ultimately, a method of improved Vessel Collision Risk Operator (VCRO) to merge risk assessments of both ships is proposed through integration of near-miss collision risks in a systematic way, which overcomes the disadvantages of prior VCROs that only consider the maximum value, from which it is difficult to track and judge the risk trend. Utilising a case study, the effectiveness of the proposed method is validated through analysis of ship encounters, with ships of different sizes in the Baltic Sea.
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Wang, Xing Hua, Shen Hua Yang, and Guo Quan Chen. "Design and Implement on Intelligent Target Ship for Ship Handling Simulator." Applied Mechanics and Materials 97-98 (September 2011): 854–58. http://dx.doi.org/10.4028/www.scientific.net/amm.97-98.854.
Full textAbstract:
Aiming at the fact that target ships of ship handling simulator have not the ability of avoiding other ships according to the COLREG 1972, the paper puts forward to add Personifying Intelligent Decision-making for Vessel Collision Avoidance, for short PIDVCA, and vessel automatic control algorithm into solver procedure of target ship, designed and realized target ships to sail according to the COLREG 1972, which make ship handling simulator more realistic simulate the actual navigation environment at sea. Finally, the paper gives the simulation pictures of 2 and 4 target ships intelligent collision.
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Yim, Jeong-Bin, and Deuk-Jin Park. "Estimating Critical Latency Affecting Ship’s Collision in Re-Mote Maneuvering of Autonomous Ships." Applied Sciences 11, no. 22 (November 19, 2021): 10987. http://dx.doi.org/10.3390/app112210987.
Full textAbstract:
Estimation of the critical latency that can cause collision in remote maneuvering of autonomous ships can provide a clue to avoid collisions. The concept of estimating the critical latency was established using the turning circle formed by the turning maneuver of the own ship, and critical latency was estimated using the radius of the turning circle with the turning time ratio. The turning circle was observed using the turning trajectory of the give-way vessel measured in the ship maneuvering simulation experiment. Experimental results demonstrated that the proposed method is capable of identifying both the location and time of the collision due to critical latency. As a result, a clue to avoid possible collision in remote maneuvering caused by critical latency was deduced.
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Zhou, Xiao-Qing, Jia-Zhu Hong, and Yong Xia. "Numerical Simulation of a Cable-Stayed Bridge Subjected to Ship Collision." International Journal of Structural Stability and Dynamics 21, no. 06 (March 24, 2021): 2150086. http://dx.doi.org/10.1142/s0219455421500863.
Full textAbstract:
Long-span cable-stayed bridges are subjected to the risk of collision from passing ships. Conducting experimental study on the collision of bridges and vessels is difficult due to high cost and limited space. In this paper, the behavior of a 1[Formula: see text]018-m long-span cable-stayed bridge subjected to ship collisions is numerically studied. Finite element models of the entire bridge and ships are established. Four different dead weight tonnages (DWT), namely, 2[Formula: see text]700, 12[Formula: see text]000, 30[Formula: see text]000, and 75[Formula: see text]000[Formula: see text]t, with impact velocities of 1[Formula: see text]m/s to 6[Formula: see text]m/s are investigated. The complete collision process under different loading scenarios is simulated, from which the collision force, bridge responses and local damage are obtained. The calculated collision force is significantly affected by the impact velocity and DWT, and exhibits a linear relationship with the impact velocity. Comparison with design codes shows that different codes vary significantly in estimating the collision force and Eurocode provides most accurate results. The effect of the material model on the collision force is also studied. This numerical study provides a reference for the ship collision design of long-span cable-stayed bridges.