• Title/Summary/Keyword: Dynamic window approach

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3D Global Dynamic Window Approach for Navigation of Autonomous Underwater Vehicles

  • Tusseyeva, Inara;Kim, Seong-Gon;Kim, Yong-Gi
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제13권2호
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    • pp.91-99
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    • 2013
  • An autonomous unmanned underwater vehicle is a type of marine self-propelled robot that executes some specific mission and returns to base on completion of the task. In order to successfully execute the requested operations, the vehicle must be guided by an effective navigation algorithm that enables it to avoid obstacles and follow the best path. Architectures and principles for intelligent dynamic systems are being developed, not only in the underwater arena but also in related areas where the work does not fully justify the name. The problem of increasing the capacity of systems management is highly relevant based on the development of new methods for dynamic analysis, pattern recognition, artificial intelligence, and adaptation. Among the large variety of navigation methods that presently exist, the dynamic window approach is worth noting. It was originally presented by Fox et al. and has been implemented in indoor office robots. In this paper, the dynamic window approach is applied to the marine world by developing and extending it to manipulate vehicles in 3D marine environments. This algorithm is provided to enable efficient avoidance of obstacles and attainment of targets. Experiments conducted using the algorithm in MATLAB indicate that it is an effective obstacle avoidance approach for marine vehicles.

무인수상정 경로점 추종을 위한 강화학습 기반 Dynamic Window Approach (Dynamic Window Approach with path-following for Unmanned Surface Vehicle based on Reinforcement Learning)

  • 허진영;하지수;이준식;유재관;권용진
    • 한국군사과학기술학회지
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    • 제24권1호
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    • pp.61-69
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    • 2021
  • Recently, autonomous navigation technology is actively being developed due to the increasing demand of an unmanned surface vehicle(USV). Local planning is essential for the USV to safely reach its destination along paths. the dynamic window approach(DWA) algorithm is a well-known navigation scheme as a local path planning. However, the existing DWA algorithm does not consider path line tracking, and the fixed weight coefficient of the evaluation function, which is a core part, cannot provide flexible path planning for all situations. Therefore, in this paper, we propose a new DWA algorithm that can follow path lines in all situations. Fixed weight coefficients were trained using reinforcement learning(RL) which has been actively studied recently. We implemented the simulation and compared the existing DWA algorithm with the DWA algorithm proposed in this paper. As a result, we confirmed the effectiveness of the proposed algorithm.

동적창과 Dijkstra 알고리즘을 이용한 항법 알고리즘에서 경로 설정 (The Pathplanning of Navigation Algorithm using Dynamic Window Approach and Dijkstra)

  • 김재준;지규인
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2021년도 추계학술대회
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    • pp.94-96
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    • 2021
  • 본 연구는 산업현장에서 사용되는 이동로봇이 익숙하지 못한 환경에서 목적지에 도착할 수 있는 항법 알고리즘을 개발하고자 한다. 이를 위해 동적창 접근(DWA)과 Dijkstra 경로설정 알고리즘을 결합하여 항법 알고리즘을 제안한다. 이를 성능 비교하기 위해 로컬 동적창 접근(LDWA), 글로벌 동적창 접근(GDWA), 고속 탐색 랜덤 트리 (RRT) 알고리즘을 비교 분석한다. LDWA과 GDWA을 적용한 Dijkstra 알고리즘을 활용한 항법 알고리즘을 구현하여 제한된 정보를 이용하여 이동로봇이 목적지에 도달할 수 있도록 한다. 이 알고리즘들의 목적지에 도착할 때까지 걸리는 시간, 장애물 회피와 계산복잡도에 대한 비교 분석한다. 위 알고리즘의 한계를 극복하기 위한 새로운 항법 알고리즘을 제안하고 제시된 최적화된 항법 알고리즘의 산업현장에서의 활용 방안을 모색한다.

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수정된 전역 DWA에 의한 자율이동로봇의 경로계획 (Path Planning for Autonomous Mobile Robots by Modified Global DWA)

  • 윤희상;박태형
    • 전기학회논문지
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    • 제60권2호
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    • pp.389-397
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    • 2011
  • The global dynamic window approach (DWA) is widely used to generate the shortest path of mobile robots considering obstacles and kinematic constraints. However, the dynamic constraints of robots should be considered to generate the minimum-time path. We propose a modified global DWA considering the dynamic constraints of robots. The reference path is generated using A* algorithm and smoothed by cardinal spline function. The trajectory is then generated to follows the reference path in the minimum time considering the robot dynamics. Finally, the local path is generated using the dynamic window which includes additional terms of speed and orientation. Simulation and experimental results are presented to verify the performance of the proposed method.

무인수상정을 위한 경로선 추종이 가능한 개선된 Dynamic Window Approach (Improved Dynamic Window Approach With Path-Following for Unmanned Surface Vehicle)

  • 김효곤;윤성조;최영호;이정우;유재관;원병재;서진호
    • 대한임베디드공학회논문지
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    • 제12권5호
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    • pp.295-301
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    • 2017
  • Recently, autonomous navigation technology, obstacle recognition, and obstacle collision avoidance technology are actively being developed for an unmanned surface vehicle (USV). The path to move from the current location to the destination should be planned, in order for an USV to autonomously operate safely to its destination. The dynamic window approach (DWA) is a well-known navigation scheme as a local path planning. The DWA algorithm derives the linear velocity and angular velocity by evaluating the destination direction, velocity, and distance from the obstacle. However, because DWA algorithm does not consider tracking the path, when using only the DWA algorithm, the ship may navigate away from the path line after avoiding obstacles. In this paper, we propose an improved DWA algorithm that can follow path line. And we implemented the simulation and compared the existing DWA algorithm with the improved DWA algorithm proposed in this paper. As a result, it is confirmed that the proposed DWA algorithm follows the path line better.

최적 경유점을 갖는 전역 DWA에 기반한 이동로봇의 주행 (Mobile Robot Navigation based on Global DWA with Optimal Waypoints)

  • 함종규;박중태;송재복
    • 제어로봇시스템학회논문지
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    • 제13권7호
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    • pp.624-630
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    • 2007
  • The dynamic window approach(DWA) is a well known technique for reactive collision avoidance. It shows safe and efficient performance in real-world experiments. However, a robot can get stuck in local minima because no information about the connectivity of the free space is used to determine the motion. The global DWA can solve this problem of local minima by adding a navigation function. Even with the global DWA, it is still difficult for a robot to execute an abrupt change in its direction, for example, entering from the corridor to a doorway. This paper proposes a modified global DWA using the included angles of waypoints extracted from an optimal path. This scheme enables the robot to decelerate in advance before turning into the doorway. Therefore the robot can reach the goal position more safely and efficiently at high speeds.

동적 물체의 비전 검출을 통한 이동로봇의 장애물 회피 (Mobile Robot Obstacle Avoidance using Visual Detection of a Moving Object)

  • 김인권;송재복
    • 로봇학회논문지
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    • 제3권3호
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    • pp.212-218
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    • 2008
  • Collision avoidance is a fundamental and important task of an autonomous mobile robot for safe navigation in real environments with high uncertainty. Obstacles are classified into static and dynamic obstacles. It is difficult to avoid dynamic obstacles because the positions of dynamic obstacles are likely to change at any time. This paper proposes a scheme for vision-based avoidance of dynamic obstacles. This approach extracts object candidates that can be considered moving objects based on the labeling algorithm using depth information. Then it detects moving objects among object candidates using motion vectors. In case the motion vectors are not extracted, it can still detect the moving objects stably through their color information. A robot avoids the dynamic obstacle using the dynamic window approach (DWA) with the object path estimated from the information of the detected obstacles. The DWA is a well known technique for reactive collision avoidance. This paper also proposes an algorithm which autonomously registers the obstacle color. Therefore, a robot can navigate more safely and efficiently with the proposed scheme.

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휴머노이드 로봇의 안전한 차량 주행 전략 및 원격 제어 인터페이스 개발 (Development of Tele-operation Interface and Stable Navigation Strategy for Humanoid Robot Driving)

  • 신세호;김민성;안준우;김상현;박재흥
    • 제어로봇시스템학회논문지
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    • 제22권11호
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    • pp.904-911
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    • 2016
  • This paper presents a novel driving system by the humanoid robot to drive a vehicle in disaster response situations. To enhance robot's capability for substituting human activities in responding to natural and man-made disaster, the one of prerequisite skills for the rescue robot is the mounted mobility to maneuver a vehicle safely in disaster site. Therefore, our driving system for the humanoid is developed in order to steer a vehicle through unknown obstacles even under poor communication conditions such as time-delay and black-out. Especially, the proposed system includes a tele-manipulation interface and stable navigation strategies. First, we propose a new type of path estimation method to overcome limited communication. Second, we establish navigation strategies when the operator cannot recognize obstacles based on Dynamic Window Approach. The effectiveness of the proposed developments is verified through simulation and experiments, which demonstrate suitable system for driving a vehicle in disaster response.

국제해상충돌예방규칙에 따른 군집 무인수상정의 편대 제어 알고리즘 연구 (A Study on the Formation Control Algorithm of Multi-USVs According to COLREGs)

  • 허진영;김현석;심성준;김주영;유재관;권용진
    • 한국군사과학기술학회지
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    • 제25권6호
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    • pp.586-595
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    • 2022
  • In this paper, we propose a formation control algorithm for multi-USVs according to COLREGs. First, we applied the Dynamic Window Approach algorithm that can reflect the kinematic characteristics for the path movement of USVs. Then, we propose a virtual structure-based virtual leader-follower method that applies the advantages of leader-follower and virtual structure methods among conventional formation control algorithms for stability. Next, we proposed a collision avoidance algorithm according to all COLREGs when encountering an opposing ship by adding COLREGs situational conditions to the virtual leader, and finally confirmed the feasibility of the proposed method through simulation.

DEA 윈도우 분석을 이용한 정부출연연구기관의 연구개발 사업화 동태적 효율성 분석 (Measuring the Dynamic Efficiency of Government Research Institutes in R&D and Commercialization by DEA Window Analysis)

  • 이성희;김태수;이학연
    • 경영과학
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    • 제32권4호
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    • pp.193-207
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    • 2015
  • Government-funded research institutes (GRIs) have played a pivotal role in national R&D in Korea. To achieve desired goals of GRIs with the limited R&D budget, their performance along with time needs to be measured and compared so that appropriate R&D policies can be formulated and implemented. This study measures the dynamic performance of GRIs from the efficiency perspective using the window model of data envelopment analysis (DEA). DEA is a non-parametric approach to measuring the relative efficiency of decision-making units (DMUs) with multiple inputs and outputs, and the DEA window model can capture the dynamic changes in efficiency of DMUs during multiple periods. The relative efficiency of GRIs is measured from the two perspectives: R&D and R&BD. Patents, papers, technology transfers are selected as outputs for R&D while compensated technology transfers and technology royalty are employed as outputs for R&BD. This study measures and compares the two types of performance of 20 Korean GRIs under the control of National Research Council of Science and Technology during the period of six years from 2008 to 2013. The results are expected to provide fruitful implications for national R&D policy making.