• 한국산업정보학회논문지
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• 제5권1호
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• pp.1-15
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• 2000

In this paper, an efficient system for finding answers to a given path algebra expression in a directed acylic graph is discussed more particulary, in a multimedia presentration graph. Path algebra expressions are formulated using revised versions of operators next and until of temporal logic, and the connected operator. To evaluate queries with path algebra expressions, the node code system is proposed. In the node code system, the nodes of a presentation graph are assigned binary codes (node codes) that are used to represent nodes and paths in a presentation graph. Using node codes makes it easy to find parent-child predecessor-sucessor relationships between nodes. A pair of node codes for connected nodes uniquely identifies a path, and allows efficient set-at-a-time evaluations of path algebra expressions. In this paper, the node code representation of nodes and paths in multimedia presentation graphs are provided. The efficient algorithms for the evaluation of queries with path algebra expressions are also provided.

• 한국정밀공학회지
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• 제19권9호
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• pp.142-150
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• 2002

This study describes a method of finding an optimal path of a soccer robot by using a concentric circle method with different radii of rotation. Comparing with conventional algorithms which try to find the shortest path length, the variable concentric circle method find the shortest moving time. The radius fur the shortest moving time for a given ball location depends on the relative location between a shooting robot and a ball. Practically it is difficult to find an analytical solution due to many unknowns. Assuming a radius of rotation within a possible range, total path moving time can be calculated by adding the times needed for straight path and circular path. Among these times the shortest time is obtained. In this paper, a graphical solution is presented such that the game ground is divided into 3 regions with a minimum, medium, and maximum radius of rotation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 D
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• pp.2732-2734
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• 2000

This paper proposes a path planning algorithm for mobile robots. To generate a minimum-distance path for mobile robots, we use the Genetic Algorithm(GA) and Visibility Graph. After finding a minimum-distance path between a start and a goal point, the path is revised to find the smooth subminimum-distance path by a path-smoothing algorithm. Simulation results show that the proposed algorithms are effective.

• 해양환경안전학회지
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• 제23권5호
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• pp.574-584
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• 2017

본 논문에서는 보행로봇의 일종인 TITAN-VIII라 불리는 로봇을 이용하여 가장 짧은 경로를 탐색하여 이동하는 방법에 관한 연구를 나타낸다. 보행로봇의 경우 바퀴구동 로봇에 비해 불규칙한 지면 위를 자유로이 이동 가능한 장점 등을 가지고 있는데 반해 이동속도는 바퀴구동 로봇에 비해 느린 편이다. 따라서 본 논문에서는 목적지에 도달하기까지 시간을 최소화하는 최적경로 탐색 제어방법을 제시하였다. 경로를 탐색하기 위해 Dijkstra's algorithm라 불리는 알고리즘을 기반으로 하여 적용하였다. 또한 로봇이 항상 정적인 자세를 유지하는 로봇의 다양한 자세에 대해서도 다루었다. 로봇의 자세제어와 알고리즘을 통하여 로봇의 관절각 결정에 필요한 여러 수학방정식을 제시하였다. 그 후 원하는 궤적으로 로봇이 이동하고 탐색하는 알고리즘을 고안하였고, 제안한 방법의 결과를 실험으로 확인하였다.

• 한국통신학회논문지
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• 제37C권10호
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• pp.925-932
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• 2012

본 논문에서는 패턴 인식 알고리즘을 기반으로 인간 형태를 가진 휴머노이드 로봇의 보행 동작을 제어하는 경로 인식 시스템을 개발하였다. 휴머노이드 로봇이 효과적인 작업 수행을 할 수 있도록 행동 프리미티브를 정의 하였으며, Canny 에지 검출 알고리즘을 적용한 보도 블록의 패턴 및 색상 추출, 이를 기반으로 한 이동 방향을 인식하는 알고리즘 제안하고, 리눅스 운영체제와 영상 카메라가 장착된 소형 휴머노이드 임베디드 시스템에 구현하였다. 제안 알고리즘의 성능 실험을 휴머노이드 로봇의 동작 속도 및 인식율에 관점에서 수행하였으며, 다양한 현실 환경을 반영하기 위해 경사도 및 조도 변화를 적용하였다. 실험 결과 제안 알고리즘은 다양한 환경에서 시각 장애인의 길안내 도우미 로봇으로서 적절한 수준에서 반응함을 확인하였다.

• 한국인터넷방송통신학회논문지
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• 제19권2호
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• pp.243-253
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• 2019

행성 탐사의 첫 번째 단계는 일반적으로 자율적 탐사선을 사용하여 수행된다. 이 탐사선은 자신의 길을 찾고 행성표면에 대한 실험을 수행 할 수 있다. 이 논문에서는 각 에이전트의 지식과 노력을 공유하기 위해 블랙보드 시스템을 효과적으로 활용하는 다중 에이전트 시스템을 제안한다. 에이전트는 BDI (Belief Desire Intension) 모델의 조합으로 반응 모델을 사용하고 최단 거리를 계산하고 행성 표면에서 이동 경로를 계산하는 경로 찾기 알고리즘을 사용한다. 이 접근법은 짧은 시간 내에 주어진 지형에서 표면 탐사를 수행 할 수 있다. 블랙보드에 수집 된 정보는 상세한 표면 토양 변화 결과를 산출하는데 사용된다. 이 연구에서 제안된 다중 에이전트 시스템에 의한 탐사는 다양한 지형 크기별로 잘 수행되는 것으로 나타났다.

• 로봇학회논문지
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• 제5권4호
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• pp.332-338
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• 2010

This paper presents a study of path-planning method for AGV(automated guided vehicle) based on path-tracking. It is important to find an optimized path among the AGV techniques. This is due to the fact that the AGV is conditioned to follow the predetermined path. Consequently, the path-planning method is implemented directly affects the whole AGV operation in terms of its performance efficiency. In many existing methods are used optimization algorithms to find optimized path. However, such methods are often prone with problems in handling the issue of inefficiency that exists in system's operation due to inherent undue time delay created by heavy load of complex computation. To solve such problems, we offer path-planning method using modified binary tree. For the purpose of our experiment, we initially designed a AGV that is equiped with laser navigation, two encoders, a gyro sensor that is meant to be operated within actual environment with given set of constrictions and layout for the AGV testing. The result of our study reflects the fact that within such environments, the proposed method showed improvement in its efficiency in finding optimized path.

• 한국정밀공학회지
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• 제12권7호
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• pp.32-45
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• 1995

In this paper, we present a new method to tool path planning problem for rough cut of pocket milling operations. The key idea is to formulate the tool path problem into a TSP (Travelling Salesman Problem) so that the powerful neural network approach can be effectively applied. Specifically, our method is composed of three procedures: a) discretization of the pocket area into a finite number of tool points, b) neural network approach (called SOM-Self Organizing Map) for path finding, and c) postprocessing for path smoothing and feedrate adjustment. By the neural network procedure, an efficient tool path (in the sense of path length and tool retraction) can be robustly obtained for any arbitrary shaped pockets with many islands. In the postprocessing, a) the detailed shape of the path is fine tuned by eliminating sharp corners of the path segments, and b) any cross-overs between the path segments and islands. With the determined tool path, the feedrate adjustment is finally performed for legitimate motion without requiring excessive cutting forces. The validity and powerfulness of the algorithm is demonstrated through various computer simulations and real machining.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.120.3-120
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• 2001

We propose a new method of path planning for cleaning robots. Path planning problem for cleaning robots is different from conventional path planning problems in which finding a collision-free trajectory from a start point to a goal point is focused. In the case of cleaning robots, however, a planned path should cover all area to be cleaned. To resolve this problem in a systematic way, we propose a method based on a graph model as follows: at first, partition a given map into proper regions, then transform a divided region to a vertex and a connectivity between regions to an edge of a graph. Finally, a region is divided into sub-regions so that the graph has a unary tree which is the simplest Hamilton path. The effectiveness of the proposed method is shown by computer simulation results.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권7호
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• pp.3100-3116
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• 2016

With the rapid development of urban traffic system and fast increasing of vehicle numbers, the traditional centralized ways to generate the source-destination shortest path in terms of travel time(the optimal path) encounter several problems, such as high server pressure, low query efficiency, roads state without in-time updating. With the widespread use of smart cameras in the urban traffic and surveillance system, this paper maps the optimal path finding problem in the dynamic road network to the shortest routing problem in the smart camera networks. The proposed distributed optimal path generation algorithm employs the delay routing and caching mechanism. Real-time route update is also presented to adapt to the dynamic road network. The test result shows that this algorithm has advantages in both query time and query packet numbers.