scholarly journals A Coordination System between Decision Making and Controlling for Autonomous Collision Avoidance of Large Intelligent Ships

2021 ◽  
Vol 9 (11) ◽  
pp. 1202
Author(s):  
Zhengyu Zhou ◽  
Yingjun Zhang ◽  
Shaobo Wang
Keyword(s):  
Collision Avoidance ◽  
Pid Control ◽  
Closed Loop ◽  
Timely Manner ◽  
System A ◽  
Dangerous Situation ◽  
Risk Algorithm ◽  
International Regulations ◽  
Coordination System ◽  
Velocity Obstacle

Large ships are typically with large inertia and longtime delay in motion, in prevailing collision avoidance methods, their maneuverability is generally neglected, there could be a dangerous situation if the system fails to control the ship course as ordered in a timely manner. This paper proposes a coordination system which consists of two algorithms for avoiding risk and then returning to scheduled waypoint. The avoiding risk algorithm are based on VO (velocity obstacle) method, the returning algorithm is derived from LOS (light of sight) guidance. For better performance, the ship model for simulation is a nonlinear Norrbin Model, with the controller improved by CGSA (closed loop gain shaping algorithm) method from traditional PID control, COLREGS (Convention on the International Regulations for Preventing Collisions at Sea) constrains are considered. To test the effectiveness of the proposed system, a series of complex scenarios including Imazu problem are applied.

scholarly journals Local Route Planning for Collision Avoidance of Maritime Autonomous Surface Ships in Compliance with COLREGs Rules

2021 ◽  
Vol 14 (1) ◽  
pp. 198
Author(s):  
Ho Namgung
Keyword(s):  
Collision Avoidance ◽  
Fuzzy Inference ◽  
Human Life ◽  
Risk Index ◽  
Route Planning ◽  
Inference System ◽  
Surface Ship ◽  
International Regulations ◽  
Planning Algorithm ◽  
Velocity Obstacle

A maritime autonomous surface ship (MASS) ensures safety and effectiveness during navigation using its ability to prevent collisions with a nearby target ship (TS). This avoids the loss of human life and property. Therefore, collision avoidance of MASSs has been actively researched recently. However, previous studies did not consider all factors crucial to collision avoidance in compliance with the International Regulations for Preventing Collisions at Sea (COLREGs) Rules 5, 7, 8, and 13–17. In this study, a local route-planning algorithm that takes collision-avoidance actions in compliance with COLREGs Rules using a fuzzy inference system based on near-collision (FIS-NC), ship domain (SD), and velocity obstacle (VO) is proposed. FIS-NC is used to infer the collision risk index (CRI) and determine the time point for collision avoidance. Following this, I extended the VO using the SD to secure the minimum safe distance between the MASS and the TS when they pass each other. Unlike previous methods, the proposed algorithm can be used to perform safe and efficient navigation in terms of near-collision accidents, inferred CRI, and deviation from the course angle route by taking collision-avoidance actions in compliance with COLREGs Rules 5, 7, 8, and 13–17.

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.

scholarly journals Path Planning for Autonomous Ships: A Hybrid Approach Based on Improved APF and Modified VO Methods

2021 ◽  
Vol 9 (7) ◽  
pp. 761
Author(s):  
Liang Zhang ◽  
Junmin Mou ◽  
Pengfei Chen ◽  
Mengxia Li
Keyword(s):  
Path Planning ◽  
Local Minimum ◽  
Hybrid Approach ◽  
Artificial Potential Field ◽  
Whole Process ◽  
International Regulations ◽  
Local Path ◽  
Velocity Obstacle ◽  
Global And Local

In this research, a hybrid approach for path planning of autonomous ships that generates both global and local paths, respectively, is proposed. The global path is obtained via an improved artificial potential field (APF) method, which makes up for the shortcoming that the typical APF method easily falls into a local minimum. A modified velocity obstacle (VO) method that incorporates the closest point of approach (CPA) model and the International Regulations for Preventing Collisions at Sea (COLREGS), based on the typical VO method, can be used to get the local path. The contribution of this research is two-fold: (1) improvement of the typical APF and VO methods, making up for previous shortcomings, and integrated COLREGS rules and good seamanship, making the paths obtained more in line with navigation practice; (2) the research included global and local path planning, considering both the safety and maneuverability of the ship in the process of avoiding collision, and studied the whole process of avoiding collision in a relatively entirely way. A case study was then conducted to test the proposed approach in different situations. The results indicate that the proposed approach can find both global and local paths to avoid the target ship.

DETERMINING ROBUST PARAMETERS IN STABILIZING SET OF BACKSTEPPING BASED NONLINEAR CONTROLLER FOR SHIP COURSE KEEPING

2021 ◽  
Vol 158 (A3) ◽  
Author(s):  
X K Zhang ◽  
G Q Zhang
Keyword(s):  
Closed Loop ◽  
Simulation Experiment ◽  
Empirical Knowledge ◽  
Backstepping Method ◽  
Nonlinear Controller ◽  
Closed Loop System ◽  
Robust Performance ◽  
System A ◽  
Uniformly Asymptotic Stability ◽  
Novel Method

In order to solve the problem that backstepping method cannot effectively guarantee the robust performance of the closed-loop system, a novel method of determining parameter is developed in this note. Based on the ship manoeuvring empirical knowledge and the closed-loop shaping theory, the derived parameters belong to a reduced robust group in the original stabilizing set. The uniformly asymptotic stability is achieved theoretically. The training vessel “Yulong” and the tanker “Daqing232” are selected as the plants in the simulation experiment. And the simulation results are presented to demonstrate the effectiveness of the proposed algorithm.

scholarly journals Distributed Cooperative Avoidance Control for Multi-Unmanned Aerial Vehicles

Actuators ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 1 ◽  
Author(s):  
Sunan Huang ◽  
Rodney Swee Huat Teo ◽  
Wenqi Liu
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Case Studies ◽  
Collision Avoidance ◽  
Hardware In The Loop ◽  
Crucial Issue ◽  
Communication Failure ◽  
Aerial Vehicles ◽  
Avoidance Control ◽  
Velocity Obstacle ◽  
Multi Uav

It is well-known that collision-free control is a crucial issue in the path planning of unmanned aerial vehicles (UAVs). In this paper, we explore the collision avoidance scheme in a multi-UAV system. The research is based on the concept of multi-UAV cooperation combined with information fusion. Utilizing the fused information, the velocity obstacle method is adopted to design a decentralized collision avoidance algorithm. Four case studies are presented for the demonstration of the effectiveness of the proposed method. The first two case studies are to verify if UAVs can avoid a static circular or polygonal shape obstacle. The third case is to verify if a UAV can handle a temporary communication failure. The fourth case is to verify if UAVs can avoid other moving UAVs and static obstacles. Finally, hardware-in-the-loop test is given to further illustrate the effectiveness of the proposed method.

Velocity obstacle based local collision avoidance for a holonomic elliptic robot

2016 ◽  
Vol 41 (6) ◽  
pp. 1347-1363 ◽  
Author(s):  
Beom H. Lee ◽  
Jae D. Jeon ◽  
Jung H. Oh
Keyword(s):  
Collision Avoidance ◽  
Velocity Obstacle

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.

Double Closed-Loop Motor Modeling and Analysis for Lunar Rover Simulation

2012 ◽  
Vol 472-475 ◽  
pp. 1971-1976 ◽  
Author(s):  
Wei Dong Huang ◽  
Hong Kui Feng ◽  
Jin Song Bao ◽  
You Sheng Xu
Keyword(s):  
Pid Control ◽  
Control Algorithm ◽  
Dynamics Simulation ◽  
Motor Drive ◽  
Modeling And Analysis ◽  
Lunar Rover ◽  
System A ◽  
Drive Control ◽  
Body Dynamics ◽  
Multi Body

Motor drive control is the major study field in the development of lunar rover. Based on the double-closed DC loop adjustable-speed system, a motor drive simulation module using a position recursive PID control algorithm is developed, which is integrated into the multi-body dynamics simulation system, to carry out the whole lunar rover simulation. And the cruise process of lunar rover locomotion in the complex lunar terrain is simulated in a virtual environment.

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