scholarly journals Ship’s Trajectory Planning Based on Improved Multiobjective Algorithm for Collision Avoidance

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Jinxin Li ◽  
Hongbo Wang ◽  
Wei Zhao ◽  
Yuanyuan Xue
Keyword(s):  
Collision Avoidance ◽  
Intelligent Algorithm ◽  
External Disturbances ◽  
Nsga Ii ◽  
Intelligent Algorithms ◽  
Action Point ◽  
International Regulations ◽  
Simulation Results ◽  
Ship Collision ◽  
Sea Area

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.

scholarly journals Multiobjective Optimization Based Vessel Collision Avoidance Strategy Optimization

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Qingyang Xu ◽  
Chuang Zhang ◽  
Ning Wang
Keyword(s):  
Multiobjective Optimization ◽  
Collision Avoidance ◽  
Collision Risk ◽  
Nsga Ii ◽  
Great Loss ◽  
Marine Traffic ◽  
Simulation Based ◽  
International Regulations ◽  
Avoidance Strategy ◽  
Rudder Angle

The vessel collision accidents cause a great loss of lives and property. In order to reduce the human fault and greatly improve the safety of marine traffic, collision avoidance strategy optimization is proposed to achieve this. In the paper, a multiobjective optimization algorithm NSGA-II is adopted to search for the optimal collision avoidance strategy considering the safety as well as economy elements of collision avoidance. Ship domain and Arena are used to evaluate the collision risk in the simulation. Based on the optimization, an optimal rudder angle is recommended to navigator for collision avoidance. In the simulation example, a crossing encounter situation is simulated, and the NSGA-II searches for the optimal collision avoidance operation under the Convention on the International Regulations for Preventing Collisions at Sea (COLREGS). The simulation studies exhibit the validity of the method.

scholarly journals An Optimized Collision Avoidance Decision-Making System for Autonomous Ships under Human-Machine Cooperation Situations

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Xiaolie Wu ◽  
Kezhong Liu ◽  
Jinfen Zhang ◽  
Zhitao Yuan ◽  
Jiongjiong Liu ◽  
...  
Keyword(s):  
Decision Making ◽  
Collision Avoidance ◽  
Autonomous System ◽  
Human Machine Interaction ◽  
Water Transportation ◽  
Risk Appetite ◽  
International Regulations ◽  
Decision Making System ◽  
Ship Collision ◽  
Machine Interaction

Maritime Autonomous Surface Ships (MASSs) are attracting increasing attention in recent years as it brings new opportunities for water transportation. Previous studies aim to propose fully autonomous system on collision avoidance decisions and operations, either focus on supporting conflict detection or providing with collision avoidance decisions. However, the human-machine cooperation is essential in practice at the first stage of automation. An optimized collision avoidance decision-making system is proposed in this paper, which involves risk appetite (RA) as the orientation. The RA oriented collision avoidance decision-making system (RA-CADMS) is developed based on human-machine interaction during ship collision avoidance, while being consistent with the International Regulations for Preventing Collisions at Sea (COLREGS) and Ordinary Practice of Seamen (OPS). It facilitates automatic collision avoidance and safeguards the MASS remote control. Moreover, the proposed RA-CADMS are used in several encounter situations to demonstrate the preference. The results show that the RA-CADMS is capable of providing accurate collision avoidance decisions, while ensuring efficiency of MASS maneuvering under different RA.

Situation Awareness of Autonomous Ship Navigation in a Mixed Environment Under Advanced Ship Predictor

2019 ◽  
Author(s):  
Lokukaluge P. Perera ◽  
Brian Murray
Keyword(s):  
Collision Avoidance ◽  
Situation Awareness ◽  
Near Miss ◽  
Assessment Procedure ◽  
Adequate Knowledge ◽  
International Regulations ◽  
Ship Navigation ◽  
Ship Collision ◽  
Regulatory Failure ◽  
Autonomous Ship

Abstract Autonomous ship navigation in a mixed environment, where remote-controlled, autonomous and manned vessels are interacting, is considered. Since these vessels can have various encounter situations, adequate knowledge on such situations should be acquired to take appropriate navigation actions. That has often been categorized as situation awareness in a mixed environment, where appropriate tools and techniques to extract the respective knowledge on ship encounter situations should be developed. The collision risk assessment procedure has an important role in the same knowledge and that can eventually be used towards the respective collision avoidance actions. Hence, possible ship collision and near-miss situations can be avoided by both humans as well as systems due to their actions. Ship collision avoidance actions are regulated by the International Regulations for Preventing Collisions at Sea 1972 (COLREGs) in open sea areas and additional local navigation rules and regulations can also enforce especially in confined waters and maritime traffic lanes. It is expected that the COLREGs and other navigation rules and regulations will be interpreted by both humans as well as systems in future vessels and those interpretations will be executed as collision avoidance actions by the respective vessels in a mixed environment. Adequate understanding on situation awareness should be achieved to overcome possible regulatory failure due to human and system decisions in these situations. Hence, this study focuses on identifying such challenges in future ship encounters with possible solutions to improve situation awareness in a mixed environment as the main contribution.

scholarly journals Vessel Multi-Parametric Collision Avoidance Decision Model: Fuzzy Approach

2021 ◽  
Vol 9 (1) ◽  
pp. 49
Author(s):  
Tanja Brcko ◽  
Andrej Androjna ◽  
Jure Srše ◽  
Renata Boć
Keyword(s):  
Fuzzy Logic ◽  
Collision Avoidance ◽  
Decision Model ◽  
Fuzzy Inference ◽  
Weather Conditions ◽  
Target Vessel ◽  
Planning Tool ◽  
Inference System ◽  
International Regulations ◽  
Input Variables

The application of fuzzy logic is an effective approach to a variety of circumstances, including solutions to maritime anti-collision problems. The article presents an upgrade of the radar navigation system, in particular, its collision avoidance planning tool, using a decision model that combines dynamic parameters into one decision—the collision avoidance course. In this paper, a multi-parametric decision model based on fuzzy logic is proposed. The model calculates course alteration in a collision avoidance situation. First, the model collects input data of the target vessel and assesses the collision risk. Using time delay, four parameters are calculated for further processing as input variables for a fuzzy inference system. Then, the fuzzy logic method is used to calculate the course alteration, which considers the vessel’s safety domain and International Regulations for Preventing Collisions at Sea (COLREGs). The special feature of the decision model is its tuning with the results of the database of correct solutions obtained with the manual radar plotting method. The validation was carried out with six selected cases simulating encounters with the target vessel in the open sea from different angles and at any visibility. The results of the case studies have shown that the decision model computes well in situations where the own vessel is in a give-way position. In addition, the model provides good results in situations when the target vessel violates COLREG rules. The collision avoidance planning tool can be automated and serve as a basis for further implementation of a model that considers the manoeuvrability of the vessels, weather conditions, and multi-vessel encounter situations.

Intelligent cooperative collision avoidance via fuzzy potential fields

Robotica ◽  
2021 ◽  
pp. 1-20
Author(s):  
Daegyun Choi ◽  
Anirudh Chhabra ◽  
Donghoon Kim
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Collision Avoidance ◽  
Fuzzy Inference ◽  
Potential Fields ◽  
Rule Base ◽  
Local Minima ◽  
Inference System ◽  
Aerial Vehicles ◽  
Different Shapes ◽  
Simulation Results

Summary This paper proposes an intelligent cooperative collision avoidance approach combining the enhanced potential field (EPF) with a fuzzy inference system (FIS) to resolve local minima and goal non-reachable with obstacles nearby issues and provide a near-optimal collision-free trajectory. A genetic algorithm is utilized to optimize parameters of membership function and rule base of the FISs. This work uses a single scenario containing all issues and interactions among unmanned aerial vehicles (UAVs) for training. For validating the performance, two scenarios containing obstacles with different shapes and several UAVs in small airspace are considered. Multiple simulation results show that the proposed approach outperforms the conventional EPF approach statistically.

scholarly journals Research on determination method of the true visibility on vessels based on radar and light intensity chart of the lighthouse

2021 ◽  
pp. 132-136
Author(s):  
Т.З. Нгуен
Keyword(s):  
Light Intensity ◽  
Collision Avoidance ◽  
Safety Management ◽  
Weather Condition ◽  
Management Systems ◽  
Determination Method ◽  
Safety Management Systems ◽  
Is Research ◽  
Visibility Condition ◽  
International Regulations

Определение истинной видимости является основной морской метеорологической операцией дежурного офицера на борту. В условиях ограниченной видимости суда должны работать в соответствии с Правилом 19 Международных правил предотвращения столкновений на море. Однако в настоящее время нет документов, которые бы четко и количественно давались в руководстве по определению видимости на море. С другой стороны, системы управления безопасностью некоторых судоходных компаний выдают предупреждения, и дежурный офицер должен уведомить или вызвать капитана, когда видимость упадет до определенного предела. Это затрудняет для дежурного офицера принятие независимого решения об избежании столкновения в случае ухудшения видимости. В целях содействия решению актуальной морской проблемы, о которой говорилось выше, целью данной работы является исследование метода определения видимости на борту судна в определенных погодных условиях. Determining the true visibility is a basic marine meteorological operation of the duty officer on board. In the restricted visibility condition, vessels must sailing in accordance with Rule 19, International regulations for preventing collisions at sea. However, there are currently no documents that given clearly and quantitative in the guidance for determining visibility at sea. Otherwise, the warnings in the safety management systems of some shipping companies were given, and the officer of watch must inform or call the captain when the visibility reduced to a certain limit. This makes it difficult for the officer of watch to give the independent collision avoidance decision in the event of reduced visibility. In order to contribute to solve the actual maritime problem which is mentioned above, the goal of the paper is research on determine method of the visibility on board in a certain weather condition.

scholarly journals Route Planning of Helicopters Spraying Operations in Multiple Forest Areas

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1658
Author(s):  
Shuping Fang ◽  
Yu Ru ◽  
Yangyang Liu ◽  
Chenming Hu ◽  
Xuyang Chen ◽  
...  
Keyword(s):  
Route Planning ◽  
Forest Pest ◽  
Ant Colony Optimization Algorithm ◽  
Intelligent Algorithm ◽  
Driving Experience ◽  
Intelligent Algorithms ◽  
Route Length ◽  
Ga Algorithm ◽  
Low Efficiency ◽  
The Cost

It is of great value to research the problem of forest pest and disease control. Currently, helicopters play an important role in dealing with this problem. However, the spraying route planning still depends on the pilot’s driving experience, which leads to low efficiency and less accurate coverage. For this reason, this paper attempts to use intelligent algorithms to plan the pesticide spraying route for helicopters. When the helicopter is conducting spraying operations in multiple forest areas, the routes are divided into two parts: pesticide spraying routes for individual forest areas and dispatch routes between multiple forest areas. First, the shorter spraying route with fewer turnarounds for individual forest areas was determined. Then a two-layer intelligent algorithm, a combination of a genetic algorithm (GA) and ant colony optimization algorithm (ACO), was designed to determine the dispatch route between multiple forest areas, which is referred to as GAACO-GA. The performance was evaluated in self-created multiple forest areas and compared with other two-layer intelligent algorithms. The results show that the GAACO-GA algorithm found the shortest dispatch route (5032.75 m), which was 5.60%, 5.45%, 6.54%, and 4.07% shorter than that of GA-GA algorithm, simulated annealing-GA (SA-GA) algorithm, ACO-GA algorithm, and particle swarm optimization-GA (PSO-GA) algorithm, respectively. A spraying experiment with a helicopter was conducted near Pigzui Mountain, Huai’an City, Jiangsu Province, China. It was found that the flight path obtained from the proposed algorithm was 5.43% shorter than that derived from a manual planning method. The dispatch route length was reduced by 16.93%, the number of turnarounds was reduced by 11 times, and the redundant coverage was reduced by 17.87%. Moreover, helicopter fuel consumption and pesticide consumption decreased by 10.56% and 5.43%, respectively. The proposed algorithm can shorten the application route, reduce the number of turnarounds and the cost of spraying operations, and has the potential for use in spraying operations in smart forestry and agriculture.

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