• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.366-368
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• 2009

본 논문에서는 모바일 로봇이 작업하는 공간상에서 빠르고 안전한 최적 경로계획을 수행할 수 있게 하는 가변적 리드 맵을 이용한 장애물 밀집 정보 기반 경로계획을 제안한다. 모바일 로봇이 작업 공간에 대해서 빠르고 안전한 경로계획을 해 클러스터링 기법을 이용하여 정적 및 동적 장애물의 분포에 대한 맵 정보를 재구성하여 정보화 시킨다. 최적의 경로계획을 위해서는 재구성된 장애물 밀집 클러스터 데이터를 이용하여 전통적 기법의 GA 방법을 변형한 최적 경로계획을 수행한다. 제안한 기술의 효율성을 검증하기 위해 그리드 기반 경로계획 중의 하나인 A*알고리즘과 다양한 맵을 이용하여 성능 비교를 수행하였다. 실험결과 제안한 경로계획 기술은 기존 알고리즘 보다 빠른 처리 성능과 동적 장애물이 밀집한 지역을 회피하는 최적 경로계획을 수행함을 확인하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3873-3879
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• 2010

Home service robot are not working in the fixed task such as industrial robot, because they are together with human in the same indoor space, but have to do in much more flexible and various environments. Most of them are developed on the base of the wheel-base mobile robot in the same method as a vehicle robot for factory automation. In these days, for holonomic system characteristics, omni-directional wheels are used in the mobile robot. A holonomicrobot, using omni-directional wheels, is capable of driving in any direction. But trajectory control for omni-directional mobile robot is not easy. Especially, azimuth control which sensor uncertainty problem is included is much more difficult. This paper develops trajectory controller of 3-wheels omni-directional mobile robot using fuzzy azimuth estimator. A trajectory controller for an omni-directional mobile robot, which each motor is controlled by an individual PID law to follow the speed command from inverse kinematics, needs a precise sensing data of its azimuth and exact estimation of reference azimuth value. It has imprecision and uncertainty inherent to perception sensors for azimuth. In this paper, they are solved by using fuzzy logic inference which can be used straightforward to perform the control of the mobile robot by means of the fuzzy behavior-based scheme already existent in literature. Finally, the good performance of the developed mobile robot is confirmed through live tests of path control task.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5051-5059
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• 2015

Structural behaviour of the front loader for an agricultural tractor was analyzed for three impact test conditions: drop and catch, corner pull, and corner push. Rigid-body dynamic, transient structural, and static structural analyses were conducted using a commercial finite element software. Analysis of the drop and catch test dealt with the case that the bucket located at the maximum elevation was dropped and catched through three steps. Analysis of the corner pull test dealt with the case that the bucket constrained to the ground by a chain at its corner was raised suddenly. Analysis of the corner push test dealt with the case that the corner of the bucket collided with an obstacle. Results of analyses of the three test conditions showed that maximum stress occurs at the geometrically discontinuous location in the mount and is caused from local stress concentration. Results of the present research can be utilized as a guideline to achieve more reliable and safe structural design of the front loaders.