• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.766-771
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• 2004

In this paper, new exploration mobile robot is presented. This mobile robot, called Robhaz-6W, is able to overcome hazardous terrains, recognize three dimensional terrain information and generate a path toward the destination by itself. We develop the passive four bar linkage mechanism adoptable to such terrain without any active control and the real time stereo vision system for obstacle avoidance, a remote control and a path planning method. And the geometrical information is transmitted to the operator in the remote site via wireless LAN equipment. And finally, experimental results for the passive mechanism, the real time stereo vision system, the path planning are reported, which show the versatility of the proposed mobile robot system to carry out some tasks.

• 한국인터넷방송통신학회논문지
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• 제9권2호
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• pp.45-50
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• 2009

청소로봇이나 경비로봇과 같이 실내에서 이동하며 작업하는 로봇에서는 센서를 통한 환경의 인식이 필수적이다. 사무실 빌딩이나 공동주택의 경우 기본적인 환경이 동일하므로 설계도와 같은 공통된 지도를 이용하면 개별 환경마다 지도를 재작성하는 것보다 유리한 점이 있다. 이때 가구나 장애물 등 위치가 바뀔 수 있는 대상의 정보는 제거하고, 벽, 문, 창 등 불변의 대상을 인식하는 것이 중요하다. 이 논문에서는 사무실이나 가정환경에서 사용할 수 있는 실험용 이동로봇을 구현하고, 레이저스캐너의 정보와 세그먼트의 방향, 위치에 의한 히스토그램 방법을 이용하여 이와 같은 불변의 특징을 추출한다. 로봇에는 레이저스캐너, 자이로 센서, 초음파 센서, 적외선 센서 등이 탑재되며 제어프로그램은 C 프로그램으로 작성되었다.

• 로봇학회논문지
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• 제13권2호
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• pp.79-85
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• 2018

This study focuses on autonomous exploration based on map expansion for an underwater robot equipped with acoustic sonars. Map expansion is applicable to large-area mapping, but it may affect localization accuracy. Thus, as the key contribution of this paper, we propose a method for underwater autonomous exploration wherein the robot determines the trade-off between map expansion ratio and position accuracy, selects which of the two has higher priority, and then moves to a mission step. An occupancy grid map is synthesized by utilizing the measurements of an acoustic range sonar that determines the probability of occupancy. This information is then used to determine a path to the frontier, which becomes the new search point. During area searching and map building, the robot revisits artificial landmarks to improve its position accuracy as based on imaging sonar-based recognition and EKF-SLAM if the position accuracy is above the predetermined threshold. Additionally, real-time experiments were conducted by using an underwater robot, yShark, to validate the proposed method, and the analysis of the results is discussed herein.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.103-104
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• 2022

Cracks may occur in reinforced concrete (RC) structures due to various physical and chemical factors, and the growth of cracks causes deterioration of the structure's performance. It is important to prevent the expansion of cracks through periodic diagnosis of cracks in structures. In order to enable free crack exploration even in a narrow space, a construction robot using a Mecanum wheel that can move up, down, left and right and rotate in place was designed. High-quality crack images were periodically collected through the camera, and the image fragments stored during the exploration were combined into a single photo after the exploration was completed. The robot detected cracks with a width of 0.2 mm or more on the concrete probe surface with an accuracy of about 90% or more.

• 로봇학회논문지
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• 제1권1호
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• pp.9-16
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• 2006

The Mobile robots are increasingly being used to perform tasks in unknown environments. The potential of robots to undertake such tasks lies in their ability to intelligently and efficiently search in an environment. An algorithm has been developed for robots which explore the environment to measure the physical properties (dust in this paper). While the robot is moving, it measures the amount of dust and registers the value in the corresponding grid cell. The robot moves from local maximum to local minimum, then to another local maximum, and repeats. To reach the local maximum or minimum, simple gradient following is used. Robust estimation of the gradient using perturbation/correlation, which is very effective when analytical solution is not available, is described. By introducing the probability of each grid cell, and considering the probability distribution, the robot doesn't have to visit all the grid cells in the environment still providing fast and efficient sensing. The extended algorithm to coordinate multiple robots is presented with simulation results.

• 한국컴퓨터정보학회논문지
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• 제18권4호
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• pp.27-34
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• 2013

모바일 로봇은 자신의 임무를 수행하기 위해 탐색 기능을 가지고 있어야 한다. 탐색은 감시 로봇, 구조 로봇, 자원 탐사 로봇 등에 사용될 수 있다. 로봇이 환경을 탐색하기 위해서는 지도와 같은 환경에 대한 정보를 가지고 있어야 한다. 그러나 기존에 많이 사용되는 그리드 지도는 용량이 너무 커서 모바일 로봇에 사용하기 힘들다는 문제를 가지고 있다. 본 논문에서는 저 사양의 모바일 로봇에서 사용할 수 있는 하이브리드 지도를 제안한다. 또한 제안하는 하이브리드 지도를 사용하여 모든 영역을 탐색하는 방법을 제안하고 있다. 제안하는 방법은 로봇의 작업 환경을 현재 처리할 수 있는 영역과 처리 할 수 없는 영역으로 나누고, 나누어진 영역을 탐색하는 동시에 지도를 업데이트하며 영역을 확장해 나간다. 탐색이 완료된 영역은 하이브리드 맵 형태로 저장한다. 생성한 하이브리드 맵을 사용하여 로봇은 장애물이 없는 영역으로 이동 경로를 생성할 수 있다. 실험결과에 따르면 기존 그리드 지도에 비해 약 6%의 메모리만을 사용해 환경 지도를 생성할 수 있었다.

• Journal of Information Processing Systems
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• 제8권3호
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• pp.471-482
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• 2012

For disaster exploration and surveillance application, this paper aims to present a novel application of a multi-robot agent based on WSN and to evaluate a multi-hop communication caused by the robotics correspondingly, which are used in the uncertain and unknown subterranean tunnel. A Primary-Scout Multi-Robot System (PS-MRS) was proposed. A chain topology in a subterranean environment was implemented using a trimmed ZigBee2006 protocol stack to build the multi-hop communication network. The ZigBee IC-CC2530 modular circuit was adapted by mounting it on the PS-MRS. A physical experiment based on the strategy of PS-MRS was used in this paper to evaluate the efficiency of multi-hop communication and to realize the delivery of data packets in an unknown and uncertain underground laboratory environment.

• 디지털융복합연구
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• 제13권1호
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• pp.185-190
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• 2015

사물인터넷의 국내외 주요 서비스 사례를 통하여 알 수 있듯이 종래 재난, 재해 등 공공 분야와 공장 자동화 등 기업 중심의 사례가 이제는 개인에 직접적으로 영향을 미치는 B2C(Business to Consumer) 서비스가 확산되고 있다. 본 논문에서는 현재 시점에서 사물인터넷(IoT) 기반 원격 제어 및 모니터링이 가능한 탐사로봇 설계를 위한 플랫폼과 부품, 그리고 네트워크 구성 방안에 대하여 제시하였다.

• International Journal of Precision Engineering and Manufacturing
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• 제9권2호
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• pp.69-74
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• 2008

Robotics and artificial intelligence are components of IT that involve networks, electrical and electronic engineering, and wireless communication. We consider an algorithm for efficient navigation by building a precise map in a multi-robot system under conditions of limited and unlimited communications. The basis of the navigation algorithm described in this paper is a wave algorithm, which is effective in obtaining an accurate map. Each robot in a multi-robot system has its own task such as building a map for its local position. By combining their data into a shared map, the robots can actively seek to verify their relative locations. Using shared maps, they coordinate their exploration strategies to maximize exploration efficiency. To prove the efficiency of the proposed technique, we compared the final results with the results in $Burgard^{8}$ and $Stachniss.^{9-10}$ All of the simulation comparisons, which are shown as graphs, were made in four different environments.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.768-771
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• 1997

Geometric probing addresses the problem of determining geometric aspects of a structure from the mathematics and results of a physical measuring device such as a probe. This paper presents a new algorithm to recognize the shape of an unknown object by using a robot hand with a force and torque sensor. The new algorithm is called S.E.P.(Shape Exploration Procedure) which finds the global shape of an unknown object. The proposed method is composed of three major parts, finding contact informations such as contact point, calculation of shape information such as curvature, and expression of global shape from these informations. Comparing with the conventional approaches, the advantages of the proposed method are explained and verified by conducting experiments with a 3-dof SCARA robot.