• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.647-652
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• 2000

This paper proposes a collision warning/avoidance algorithm using a trajectory prediction method. This algorithm is based on 2-dimensional kinematics and the Kalman filter has been used to obtain the information of the object vehicle. This algorithm has been investigated via computer simulation and showed a good trajectory prediction performance. The proposed collision warning/avoidance algorithm would enhanced driver acceptance for a collision warning/avoidance system.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2023년도 춘계학술대회
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• pp.265-266
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• 2023

With the development of science and technology, various research on ship collision avoidance has also developed rapidly. The research and development of ship collision avoidance technology has also received high attention from many researchers. This paper proposes a new collision avoidance algorithm for ships based on the artificial force field collision avoidance method. Using the simulation platform, the simulation results show that ships can successfully avoid collision in open water under single ship and multi ship situations, and the research results are relatively ideal.

• 대한조선학회논문집
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• 제56권1호
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• pp.75-81
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• 2019

This study presents an automatic collision avoidance algorithm for autonomous navigation of unmanned surface vessels. The performance of the collision avoidance algorithm is heavily dependent on the estimation quality of the course and speed of traffic ships because collision avoidance maneuvers should be determined based on the predicted motions of the traffic ships and their trajectory uncertainties. In this study, the collision avoidance algorithm is implemented based on the Probabilistic Velocity Obstacle (PVO) approach considering the maritime collision regulations (COLREGs). In order to demonstrate the performance of the proposed algorithm, an extensive set of simulations was conducted and the results are discussed.

• 한국정밀공학회지
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• 제14권1호
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• pp.158-167
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• 1997

For the use of a mobile robot in dynamic environment, a collision-avoidance algorithm with moving obsta- cle is necessary. In this paper, a collsion-avoidance algorithm of a mobile robot is presented, when a mobile robot detects the collision with moving obstacle on the navigational path. Using reported positions of moving obstacle with sensors, the mobile robot predicts the next position of moving obstacle with possibility of collision. The velocity of moving obstacle is modeled as random walk process with Gaussian distribution. The optimal collision-avoidance path in which turning motion of the mobile robot is considered is generated with relative velocity between the mobile robot and moving obstacle. For the safety of collision-avoidance path, attractive potential with the safety factor is suggested. The simulation results using this algorithm show the mobile robot avoids collision with moving obstacle in many cases.

• 대한조선학회논문집
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• 제61권2호
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• pp.106-114
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• 2024

In the 21st century, the rapid development of automation and artificial intelligence technologies is driving innovative changes in various industrial sectors. In the transportation industry, this is evident with the commercialization of autonomous vehicles. Moreover research into autonomous navigation technologies is actively underway in the aviation and maritime sectors. Consequently, for the practical implementation of autonomous ships, an effective collision avoidance algorithm has become a crucial element. Therefore, this study proposes a collision avoidance algorithm based on the Obstacle Zone by Target(OZT), which visually represents areas with a high likelihood of collisions with other ships or obstacles. The A-star algorithm was utilized to represent obstacles on a grid and assess collision risks. Subsequently, a collision avoidance algorithm was developed that performs fuzzy control based on calculated waypoints, allowing the vessel to return to its original course after avoiding the collision. Finally, the validity of the proposed algorithm was verified through collision avoidance simulations in various encounter scenarios.

• 제어로봇시스템학회논문지
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• 제10권11호
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• pp.1065-1070
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• 2004

Optimal collision avoidance algorithm for unmanned aerial vehicles based on proportional navigation guidance law is investigated this paper. Although proportional navigation guidance law is widely used in missile guidance problems, it can be used in collision avoidance problem by guiding the relative velocity vector to collision avoidance vector. The optimal navigation coefficient can be obtained if an obstacle if an obstacle moves at constant velocity vector. The stability of the proposed algorithm is also investigated. The stability can be obtained by choosing a proper navigation coefficient.

• Journal of Information Processing Systems
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• 제16권6호
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• pp.1324-1342
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• 2020

Various modified algorithms of rapidly-exploring random tree (RRT) have been previously proposed. However, compared to the RRT algorithm for collision avoidance with global and static obstacles, it is not easy to find a collision avoidance and local path re-planning algorithm for dynamic obstacles based on the RRT algorithm. In this study, we propose boundary-RRT*, a novel-algorithm that can be applied to aerial vehicles for collision avoidance and path re-planning in a three-dimensional environment. The algorithm not only bounds the configuration space, but it also includes an implicit bias for the bounded configuration space. Therefore, it can create a path with a natural curvature without defining a bias function. Furthermore, the exploring space is reduced to a half-torus by combining it with simple right-of-way rules. When defining the distance as a cost, the proposed algorithm through numerical analysis shows that the standard deviation (σ) approaches 0 as the number of samples per unit time increases and the length of epsilon ε (maximum length of an edge in the tree) decreases. This means that a stable waypoint list can be generated using the proposed algorithm. Therefore, by increasing real-time performance through simple calculation and the boundary of the configuration space, the algorithm proved to be suitable for collision avoidance of aerial vehicles and replanning of local paths.

• 해양환경안전학회지
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• 제25권2호
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• pp.169-177
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• 2019

다수의 선박이 조우하였을 경우, 충돌 피항을 위해 상대 선박의 의도를 파악하는 것은 매우 중요한 문제이다. 또한 다수의 선박의 의도를 동시에 고려하여 충돌 피항 계획을 세우는 것은 항해사에게 큰 부담이 될 수 있다. 이를 위해 분산 알고리즘이 제안 되었다. 분산 알고리즘은 각각의 선박이 다수의 상대 선박과 정보 교환을 통해 안전한 코스를 탐색할 수 있도록 한다. 본 논문에서는 분산 알고리즘의 하나인 분산 확률 탐색 알고리즘을 선박 충돌 피항에 적용하였다. 분산 확률 탐색 알고리즘에서 선박은 비용 감소가 가장 큰 코스와 기존의 코스를 확률과 제한 조건에 따라 선택한다. 분산 확률 탐색 알고리즘은 확률과 제한 조건에 따라 다섯 가지 종류로 나눠진다. 본 논문에서는 다섯 가지 종류의 분산 확률 탐색 알고리즘을 선박 충돌 피항을 위해 적용하였으며 선박 충돌 피항에 미치는 영향을 분석하였다. 또한 어떠한 분산 확률 탐색 알고리즘이 충돌 피항에 적합한지를 실험하였다. 실험 결과 다섯 가지 버전의 분산 확률 탐색 알고리즘에서 A와 B방식이 효과적으로 선박 충돌 피항을 수행하였다. 본 알고리즘은 분산 시스템 환경에서 선박 충돌 방지를 위해 적용 가능할거라 기대된다.

• 한국통신학회논문지
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• 제36권3B호
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• pp.248-253
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• 2011

선박의 충돌회피 알고리즘은 인적 요인에 의한 해난사고를 방지하고, 보다 효과적이고 안전한 운항을 위해 개발되어 왔다. 본 논문에서는 충돌사고의 위험성을 줄이고, 안전운항을 지원하기 위하여, 베이지안 추정 이론을 이용하여 충돌 위험도를 추정하는 알고리즘을 고안한다. 기존의 선박 충돌 회피를 시스템보다 안전한 충돌 회피를 위해서 베이지안 추정 이론을 이용하여 충돌 위험도를 계산하고 일정 시간 이후에 타선들의 위치 및 속도정보와 자선의 위치 및 속도정보를 이용하여 충돌 위험도를 예측함으로써 보다 안전하고 효율적인 충돌 위험도를 결정한다. 본 논문에서 타선박의 항해정보는 AIS 정보를 가정하였고, 기존의 DCPA와 TCPA를 이용한 퍼지 추론 방법보다 효율적으로 충돌 위험도를 추정할 수 있다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1996년도 추계학술대회 학술발표 논문집
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• pp.279-282
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• 1996

Collision avoidance is a method to direct a mobile robot without collision when traversing the environment. This kind of navigation is to reach a destination without getting lost. In this paper, we use a genetic algorithm for the path planning and collision avoidance. Genetic algorithm searches for path in the entire, continuous free space and unifies global path planning and local path planning. It is a efficient and effective method when compared with traditional collision avoidance algorithm.