• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제8권11호
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• pp.449-456
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• 2019

본 논문은 진공을 이용한 흡착방식과 바퀴형 이동방식을 사용하는 벽면 이동로봇의 구성과 이러한 임베디드 환경에 적합하고 기계학습에 기반한 벽면 균열 자동 검출 알고리즘의 성능 비교에 관한 연구이다. 임베디드 시스템 환경에서 객체 학습을 위해 YOLO 등 최근에 시도된 학습 방법들을 적용하여 성능을 비교, 검토하였으며 기존의 에지 검출 알고리즘들과도 성능을 비교하였다. 결국, 본 연구에서는 균열검출을 잘하며 임베디드 환경에도 적합한 최적의 기계학습방법을 선택하고 기존 방법과 성능을 비교하여 우수성을 제시하였다. 또한, 검출된 균열의 영상을 저장하고 위치 정보를 추정하여 균열에 대한 정보를 관리자 기기로 전송하는 지능적인 문제해결 기능을 구축하였다.

• 제어로봇시스템학회논문지
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• 제4권6호
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• pp.772-779
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• 1998

본 논문에서는 강인한 비선형 예측제어기를 개발하여 연구용 원자로 벽면검사를 위한 수중로봇에 적용하여 보았다. 비선형 예측제어기는 먼저 적절한 함수 확장을 이용하여 시스템의 미래 출력 값을 예측하고, 예측값과 설정치와의 차이를 최소화시키는 제어입력을 구하여 시스템에 인가한다. 이러한 제어기에 의한 폐회로 동특성은 목적함수가 상태변수로 이루어진 경우는 항상 안정한 특성을 보이고 목적함수가 출력변수으로 이루어진 경우는 상대 계수가 4이하인 경우에 안정한 특성을 보인다. 이 제어기는 기존의 비선형 제어기가 적용 불가능한 시스템에도 적용 가능한 장점을 가지고 있다. 시스템의 불확실성이 큰 경우, 제어 안정도 및 제어 성능을 향상시키기 위하여 감독제어를 비선형 예측제어기에 포함시켰다. 이러한 제어기를 수중 벽면 주행로봇에 대한 모사실험에 적용한 결과 제어기의 강인함과 제어 성능 향상을 볼 수 있었다.

• 대한조선학회 특별논문집
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• 대한조선학회 2006년도 특별논문집
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• pp.112-121
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• 2006

The vertical displacement of a ship on the basis of the sea level is an important parameter for its stability and control. To indicate the displacement on operating conditions, "draft marks" are carved on the hull of the ship in various ways. One of the methods is welding. The position, shape and size of the marks are specified on the shipbuilding rules by classification societies to be checked by shipbuilders. In most cases, high-skilled workers do the welding along the drawing for the marks and welding bead becomes the marks. But the inaccuracies due to human errors and high labor cost increase the needs for automating the work process of the draft marks. In the preceding work, an indoor robot was developed for automatic marking system on flat surfaces and the work proved that the robot welding was more effective and accurate than manual welding. However, many parts of the hull structure constructed at the outdoor are cowed shapes, which is beyond the capability of the robot developed for the indoor works on the flat surface. The marking on the curved steel surface requiring the 25m elevations is one of the main challenges to the conventional robots. In the present paper, the robot capable of climbing vertical curved steel surfaces and performing the welding at the marked position by effectively solving the problems mentioned earlier is presented.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.314-319
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• 2005

When a robot navigates in the real environment, it frequently meets various environments that can be expressed by simple geometrical shapes such as fiat floor, uneven floor, floor with obstacles, slopes, concave or convex corners, etc. Among them, the convex corner composed of two plain surfaces is the most difficult one for the robot to negotiate. In this paper, we propose a gait planning algorithm to help the robot overcome the convex environment. The trajectory of the body is derived from the maximum distance between the edge boundary of the corner and the bottom of the robot when it travels in the convex environment. Additionally, we find the relation between kinematical structure of the robot and its ability of avoiding collision. The relation is realized by considering the workspace and the best posture of the robot in the convex structure. To provide necessary information for the algorithm, we use an IR sensor attached in the leg of the robot to perceive the convex environment. The validity of the gait planning algorithm is verified through simulations and the performance is demonstrated using a quadruped walking robot, called "MRWALLSPECT III"( Multifunctional Robot for WALL inSPECTion version 3).

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
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• pp.33-36
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• 2010

The attention in construction Automation is getting higher since it could be the answer to the lack of skilled labor by decrease in construction population and aging which adversely affects productivity and quality in the construction site. We are on the way to develop a construction automation system adequate for domestic circumstances in Korea; it is called RCA(Robotic-crane based Construction Automation)system. Climbing hydraulic robots system is a part of RCA system and makes Construction factory(CF) climb through the guide rail on the core wall. The safety of climbing hydraulic robots system is at issue due to the overloaded weight of CF. Preventing this issue, present study did the design verification through the structural analysis and the simulation. Mock-up test also was done to analyze the drive performance of climbing hydraulic robots system.

• 로봇학회논문지
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• 제2권2호
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• pp.161-167
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• 2007

It is dangerous that an inspector overhauls defects and condition of the inner parts of an oil tanker because of many harmful gases, complex structures, and etc. However, these inspections are necessary to many oil tankers over old years. In this study, we proposed the design of mobile robot for inspection of CAS in oil tanker. The developed CAS inspection mobile robot has four modules, a measurement module of oil tanker's thickness, a corrosion inspection module, a climbing module of the surface on a wall, and a monitoring module. In order to get over at a check position, the driving control algorithm was developed. Magnetic wheels are used to move on the surface of a wall. This study constructed a communication network and the monitoring program to operate the developed mobile robot from remote sites. In order to evaluate the inspection ability, the experiments about performance of CAS inspection using the developed mobile robot have been carried out.

• 대한조선학회논문집
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• 제47권1호
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• pp.88-92
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• 2010

We propose a new design of the hybrid-magnet wheel to make it possible for a mobile robot to be attached to the vertical plane and be in motion. In the new suggested design, a permanent magnet is utilized to enhance the adhesive force, while an electromagnet is adopted to reduce the magnetic field and the adhesive force for detaching easily. To analysis the performance of the robot, 3 dimensional finite element analysis is executed using commercial electromagnetic analysis program, Maxwell. The results show that the adhesive force is reduced effectively by the electromagnet in the new designed robot system.

• 한국산학기술학회논문지
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• 제12권12호
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• pp.5450-5456
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• 2011

선박을 건조하는 수많은 공정 중에서 화물창 내의 도장작업은 대부분 고공에서의 작업뿐만 아니라 밀폐된 탱크 내에서 작업을 하는 경우가 많기 때문에 항상 사고의 위험에 노출되어 있다. 이러한 문제를 해결하는 방법으로 진공 펌프와 로봇에 장착된 흡착판을 이용하여 로봇을 벽면에 부착하는 방법이 개발되어져 왔다. 하지만 이러한 방법들은 다양한 재질의 벽면에 적용이 가능하다는 장점이 있는 반면에 흡착판이 고착된 상태에서 이동하기 힘들다는 것과 부착을 위해 부가장비와 그에 따른 제어가 요구된다는 단점이 있다. 이러한 단점을 보완하기 위해 본 논문에서는 자석의 성질을 이용하여 선체의 평면, 수직면까지 매달린 채도 이동가능한 자석대차를 이용한 자동 도장 로봇장치를 제안한다. 또한 시제작품을 제작하여 성능 실험을 위해 자석바퀴 부착력, 대차부착력, 견인력 및 자동주행실험을 하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.635-638
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• 2000

It is necessary to work on a vertical plane of workpiece in order to produce a large structure like a ship. These works can be automated by using the robot with permanent magnet wheels. We developed the permanent magnet wheel which can be used by a mobile robot and easily detached. We enhanced an adhesive power by restricting the occurrence direction of magnetic flow. And we also developed a method which weakens adhesive magnetic force by changing magnetic flow with metal pins. We used the load cell and the gaussmeter to measure the characteristics of the adhesive force and magnetic force. We obtained the result that the adhesive power is reduced to 1/3 of normal state by using 4 inducing pins.

• Journal of Magnetics
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• 제15권3호
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• pp.128-131
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• 2010

In this paper, we propose a new design of the permanent magnet reluctance wheel which will make it possible to attach the robot to a vertical plane and move it. In the newly suggested design, a permanent magnet is utilized to enhance the adhesive force during attachment, and an electromagnet is produced to weaken the magnetic field of the permanent magnet and reduce the adhesive force for easier detachment of wheels from steel plates. To characterize the performance of this new wheel design, a 3-D finite element analysis is executed using a commercial FE program. The results show that the adhesive force is reduced effectively by the electromagnet which flows in the reverse direction of the magnetic loop of the permanent magnet when the current is supplied to the coil.