• 한국생산제조학회지
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• 제24권1호
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• pp.98-102
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• 2015

This paper proposes an autonomous navigation method for a nonholonomic mobile robot, based on the generalized Voronoi diagram (GVD). We define the look-ahead point for a given motion constraint to determine the direction of motion, which solves the problem of a minimum turning radius for the real nonholonomic mobile robot. This method can be used to direct the robot to explore an unknown environment and construct smooth feedback curves for the nonholonomic robot. As the trajectories can be smoothed, the position of the robot can be stabilized in the plane. The simulation results are presented to verify the performance of the proposed methods for the nonholonomic mobile robot. Furthermore, this approach is worth drawing on the experience of any other mobile robots.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.174-179
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• 2003

Through the simultaneous localization and map building (SLAM) technique, a robot can create maps about its unknown environment while it continuously localizes its position. Grid maps and feature maps have been widely used for SLAM together with application of probability methods and POMDP (partially observed Markov decision process). But this approach based on grid maps suffers from enormous computational burden. Topological maps, however, have drawn more attention these days because they are compact, provide natural interfaces, and are easily applicable to path planning in comparison with grid maps. Some topological SLAM techniques like GVG (generalized Voronoi diagram) were introduced, but it enables the robot to decide only whether the current position is part of GVG branch or not in the GVG algorithm. In this paper, therefore, to overcome these problems, we present a method for updating a global topological map from the local topological maps. These local topological maps are created through a labeled Voronoi diagram algorithm from the local grid map built based on the sensor information at the current robot position. And the nodes of a local topological map can be utilized as the features of the environment because it is robust in light of visibility problem. The geometric information of the feature is applied to the extended Kalman filter and the SLAM in the indoor environment is accomplished. A series of simulations have been conducted using a two-wheeled mobile robot equipped with a laser scanner. It is shown that the proposed scheme can be applied relatively well.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제35권1호
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• pp.119-136
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• 2021

과학영재교육원 사사과정에서 Mathematica, Microsoft Excel, GeoGebra 등 공학도구를 사용하여 탐구과정을 진행하였다. 탐구팀은 주제에 따라 적절한 공학도구를 선정하였으며, 공학도구를 사용하여 특정한 상황에서 문제를 해결하고 그 결과를 관찰하여 규칙을 찾았으며, 찾은 규칙을 일반화하여 수학적으로 증명하였다. 수학 전문 소프트웨어인 Mathematica를 순환소수의 순환마디와 순환마디의 길이를 구하는 탐구활동에서 사용하였으며, 스프레드시트 소프트웨어인 Microsoft Excel을 이용하여 Beatty 수열을 탐구하였다. 동적 기하 소프트웨어인 GeoGebra를 Voronoi 다이어그램의 탐구활동에 사용하였으며 Voronoi 게임을 고안하고 게임을 진행하는 Voronoi 게임판을 만들었다. 공학도구를 이용하여 문제를 해결하고, 결과를 관찰하여 찾아낸 성질들을 수학적으로 표현하고 일반화하는 과정에서 사사과정 학생들의 수학적 창의력과 논리적 사고력이 증진되었다.