• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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• pp.1258-1261
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• 1993

This paper presents a methodology of path planning and navigation for an autonomous mobile robot. A fast algorithm using decomposition technique, which computes the optimal paths between all pairs of nodes, is proposed for real-time calculation. The robot is controlled by fuzzy approximation reasoning. Our new methodology has been implemented on a mobile robot. The results show that the robot successfully navigates to its destination following the optimal path.

• 대한산업공학회지
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• 제32권3호
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• pp.226-235
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• 2006

Telematics is expected to be one of the fastest growing businesses in information technology area. It may create a new emerging market in industry related to automotive, telecommunications, and information services. Especially vehicle navigation service is considered as a killer application among telematics service applications. The current vehicle navigation service typically recommends a single path that is based on the traveling time or distance from the origin to the destination. The system provides two options for users to choose either via highway or via any road. Since the traffics and road conditions of big cities are very complicated and dynamic, the demand of multi-path guidance system is increasing in telematics market. The multi-path guidance system should allow drivers to choose a path based on their individual preferences such as traveling time, distance, or route familiarity. Using the Lawler's algorithm, it is possible to find multiple paths; however, due to the lengthy computational time, it is not suitable for the real-time services. This study suggests a computationally feasible and efficient heuristic multiple paths finding algorithm that is reliable for the real-time vehicle navigation services.

• 한국산업융합학회 논문집
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• 제14권2호
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• pp.53-57
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• 2011

Military and commercial unmanned vehicle navigation systems are being actively studied in the field of robotics. In this study, GPS-based path generation algorithm Film Festival and the system can compensate for the shortcomings of applying a map-based path plan, the unmanned vehicle navigation systems to improve the performance of path planning algorithms are introduced.

• ETRI Journal
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• 제43권4호
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• pp.580-593
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• 2021

When operating in confined spaces or near obstacles, collision-free path planning is an essential requirement for autonomous exploration in unknown environments. This study presents an autonomous exploration technique using a carefully designed collision-free local planner. Using LiDAR range measurements, a local end-point selection method is designed, and the path is generated from the current position to the selected end-point. The generated path showed the consistent collision-free path in real-time by adopting the Euclidean signed distance field-based grid-search method. The results consistently demonstrated the safety and reliability of the proposed path-planning method. Real-world experiments are conducted in three different mines, demonstrating successful autonomous exploration flights in environment with various structural conditions. The results showed the high capability of the proposed flight autonomy framework for lightweight aerial robot systems. In addition, our drone performed an autonomous mission in the tunnel circuit competition (Phase 1) of the DARPA Subterranean Challenge.

• International Journal of Internet, Broadcasting and Communication
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• 제8권1호
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• pp.27-32
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• 2016

The global positioning system (GPS)-enabled mobile phones provide location-based applications such as car and pedestrian navigation services. The pedestrian navigation services provide safe and comfortable route and path guidance for pedestrians and handicapped or elderly people. One of the essential components for a navigation system is a spatial database used to perform navigation and routing functions. In this paper, we develop modeling and categorization of pedestrian path components for smart tour guide services using the mobile pedestrian navigation application. We create pedestrian networks using 2D base map and sky view map in urban area. We also construct pedestrian networks and attributes of node, link, and POI using on-site GPS data and photos for smart pedestrian tour guide in the major walking tourist spots in Jeju.

• 제어로봇시스템학회논문지
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• 제20권2호
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• pp.138-142
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• 2014

This research presents an A* based algorithm which can be applied to Unmanned Ground Vehicle self-navigation in order to make the driving path smoother. Based on the grid map, A* algorithm generated the path by using straight lines. However, in this situation, the knee points, which are the connection points when vehicle changed orientation, are created. These points make Unmanned Ground Vehicle continuous navigation unsuitable. Therefore, in this paper, B-spline curve function is applied to transform the path transfer into curve type. And because the location of the control point has influenced the B-spline curve, the optimal control selection algorithm is proposed. Also, the optimal path tracking speed can be calculated through the curvature radius of the B-spline curve. Finally, based on this algorithm, a path created program is applied to the path results of the A* algorithm and this B-spline curve algorithm. After that, the final path results are compared through the simulation.

• 제어로봇시스템학회논문지
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• 제18권4호
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• pp.359-364
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• 2012

Real-Time Traversability should be analyzed from the equiped sensors' data in real time for autonomous outdoor navigation. However, it is difficult to find out such traversability that considers the terrain roughness and the vehicle dynamics especially in case of skid type vehicle. The traversability based on real time dynamic analysis was proposed to solve such problem but in navigation with strait driving path. To adapt the method into the navigation with curved driving path, a path following controller should be incorporated into the dynamic model even though it cause the real time problem. In this paper, a dynamic model is proposed to solve the real time problem in the traversability analysis based on real time dynamic simualtion. The dynamic model contains the control dummy which is connected to the vehicle body with a universal joint to follow the curved path without controller. Simulation and experimental results on $6{\times}6$ articulated unmanned ground vehicle demonstrate the method's effectiveness and applicability into the traversability analysis on terrain with bumps.

• 한국군사과학기술학회지
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• 제14권6호
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• pp.993-1001
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• 2011

Unmanned ground vehicle for facility protection mostly uses model of territory for autonomous navigation. However, modeling of territory using several sensors is highly time consuming and sometimes inefficient for road application. Therefore, an estimation of drivable path based on features of road is required for high speed autonomous navigation on road. In this paper, an estimation method of drivable path using camera and 2D laser rangefinder is proposed. First, a vanishing point is estimated based on image data from CCD camera. Second, a road width is estimated based on range data from 2D laser rangefinder. Finally, the drivable path is estimated by fusing the vanishing point and the road width. The proposed method is tested on both well-structured road and unpaved road like cross-country situation.

• 한국정보과학회논문지:소프트웨어및응용
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• 제37권8호
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• pp.641-646
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• 2010

스테레오 카메라를 갖춘 인간형 로봇이 자율적으로 주변 상황을 인지하면서 목적지까지의 경로를 실시간으로 생성 및 수정하는 간단한 알고리즘을 제시한다. 특징점들을 시각적 이미지에서 추출함으로써 주위의 장애물들을 인지한다. 인간형 로봇의 뒤뚱거리는 보행 움직임을 모델링함으로써 로봇의 중심부 기준에서의 실제 경로를 유추하여 계획된 경로와 비교함으로써 시각적 피드백 제어를 구현하고 성공적인 네비게이션을 수행한다. 실제 인간형 로봇의 네비게이션 실험을 통해 제안된 알고리즘의 가능성을 입증한다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 추계종합학술대회
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• pp.561-564
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• 2007

사람이 걸을 때와는 달리 차량으로 이동할 경우 좌회전, U턴 동의 방향 전환시 교통신호를 받거나 속도를 줄여야만 하는 지연시간이 존재한다. 동일한 거리를 이동한다면 방향전환이 많은 경로보다 직진 구간이 많은 경로가 목적지에 더 빨리 도착할 가능성이 높다. 기존의 연구 중 이러한 직진성을 고려한 경로탐색은 연구되어 지지 않았다. 이 논문에서는 방향전환이 이루어지는 경로에 대해 가중치를 부여하여 직진성을 높인 경로 탐색 방법을 소개한다. 또한, 기존의 $A^*$ 알고리즘에서 맨하탄 거리를 휴리스틱으로 사용할 때와 제안하는 휴리스틱을 이용한 방법으로 탐색된 경로를 비교해 보았다. 실험결과 직진성이 약 30% 가량 향상되었으며 이동거리는 약 3.3%가량 축소되는 결과를 보였다.