• 대한기계학회논문집A
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• 제32권5호
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• pp.437-443
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• 2008

In this paper, analysis and control of the flexible multibody system using MATLAB is presented. The equations of motion of a flexible body are derived in terms of the modal coordinate. The rigid-flexible multibody dynamic solver is developed. Finite element information required to analyze motion of flexible bodies is imported from ANSYS. The modified finite element data, such as modal mass matrix, modal stiffness matrix and constraint mode shapes, is calculated in the solver. Since the solver is developed using MATLAB, it is very easy to connect with SIMULINK which is widely used to control motion of the multibody system. Several simulations are implemented to verify the developed solver. A control example is carried out and the usefulness of the developed solver is demonstrated.

• 로봇학회논문지
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• 제3권2호
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• pp.106-111
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• 2008

This paper presents a decentralized coordination for a small-scale mobile robot teams performing a task through cooperation. Robot teams are required to generate and maintain various geometric patterns adapting to an environment and/or a task in many cooperative applications. In particular, all robots must continue to strive toward achieving the team's mission even if some members fail to perform their role. Toward this end, given the number of robots in a team, an effective coordination is investigated for decentralized formation control strategies. Specifically, all members are required first to reach agreement on their coordinate system and have an identifier (ID) for role assignment in a self-organizing way. Then, employing IDs on individual robots within a common coordinate system, a decentralized neighbor-referenced formation control is realized to generate, keep, and switch between different geometric shapes. This approach is verified using an in-house simulator and physical mobile robots. We detail and evaluate the formation control approach, whose common features include self-organization, robustness, and flexibility.

• Spatial Information Research
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• 제11권4호
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• pp.481-491
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• 2003

본 연구는 기타원점좌표체계의 지적자료를 통일원점좌표계로 변환하여 연속된 형태로 제작함으로써 GIS 분야에서 지적자료의 활용성을 높이는데 목적을 두고 진행되었다. 이를 위해 경기도 오산시를 대상으로 관련기관의 협조를 받아 실험연구를 실시하였다. 실험연구에서는 좌표변환에 활용되는 기준점 영역을 대 영역, 중 영역, 소 영역 3단계로 구분하였다. 또한, 최초 기타 원점 측량당시의 기준점 성과와 현재 업무에 활용하고 있는 기준점성과를 활용하여 그 결과를 비교하였다. 실험연구에서 사용한 좌표변환 방법은 2차원 투영변환 중 대표적인 등각사상변환, 부등각사상변환, 다항식변환 방법을 적용하였다. 변환 전·후의 필지 모양 및 형태변화를 측정하고, 최종적으로는 좌표계 통일후 인접지역에 대한 이격거리를 측정하여 가장 적정한 좌표변환 방안을 설정하였다. 실험연구 결과 대 영역의 부등각사상변환이 모양 및 형태변화와 이격거리에 있어 가장 양호한 값을 나타내었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.789-792
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• 2003

Pipe inspection has a great importance to ensure safety for the nuclear power plant. In this paper, we designed visual inspection module for the tube internal, which diameter is 15${\sim}$20mm. And we made inspection module which consisted of CCD camera and light. And the relation between image and real world coordinate is established. Image processing is performed to calculate mapping parameter and analyze the size of defect. For the calculation of mapping parameter, experiment is performed using grid type test pattern. Acquired image is processed to extract image coordinate. Edge detection, thresholding, median filtering and morphology filtering is applied to extract grid pattern. Extracted image coordinate is used to calculate image to real world mapping. Lens distortion was considered and corrected to get exact data. Coordinate transformation data is provided for the users to recognize easily. Experiment was performed using grid type test pattern, we extracted lens distortion parameter and real coordinate of defect point. Radial distortion of lens was corrected but tangential distortion was not considered. As continuum to this study, the tangential distortion of lens is considered and improvement of analy zing technique for the tube internal be explored continuously.

• 한국항해항만학회지
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• 제26권5호
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• pp.537-542
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• 2002

최근에, 자동화 크레인 제어 시스템은 빠른 속도와 신속한 수송이 요구되어 지고 있다. 따라서, 컨테이너가 초기좌표에서 최종좌표로 이동될 때 컨테이너 경로는 최소시간에 흔들림 없이 설계되어야 한다. 이를 위해 본 연구에서는 최종 좌표까지 이동에서 충돌을 피하기 위하여 충돌방지 경로를 계산하였다. 그리고, 정확한 주행 제어를 위해서 신경회로망 예측 PID제어기를 구성하였다. 제안된 예측제어 시스템은 PID 파라미터를 생산하기 위하여 신경회로망 예측기, PID 제어기 그리고 신경회로망 자기 동조기로 구성하였다 크레인 시스템을 통한 시뮬레이션 분석에서 다른 기존의 제어기들 보다 우수한 제어 수행을 증명하였다.

• 제어로봇시스템학회논문지
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• 제16권9호
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• pp.883-890
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• 2010

This paper proposes tip position control system which uses a visual marker to determine the tip position of a robot manipulator. The main idea of this paper is to introduce visual marker for the tracking control of a robot manipulator. Existing researches utilize stationary markers to get pattern information from them. Unlike existing researches, we introduce visual markers to get the coordinates of them in addition to their pattern information. Markers need not be stationary and the extracted coordinate of markers are used as a reference trajectory for the tracking control of a robot manipulator. To build the proposed control scheme, we first obtain intrinsic parameters through camera calibration and evaluate their validity. Secondly, we present a procedure to obtain the relative coordinate of a visual marker with respect to a camera. Thirdly, we derive the equation for the kinematics of the SCORBOTER 4pc manipulator which we use for control of manipulator. Also, we provide a flow diagram of entire visual marker tracking system. The feasibility of the proposed scheme will be demonstrated through real experiments.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.440-445
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• 1993

A two dimensional large scale laser digitizer with a cordless cursor was developed. The coordinate detecting scheme of this digitizer is fundamentally based on the triangulation method, in which two laser-rays are scanned by the rotating plane mirros, reflected backward by the cursor, reflected again by the rotating mirrors, and detected by optical sensors. From angles in which the cursor reflections are detected, we can determine the position of the cursor. But this method involves several problems about optical alignment and its calibration especially when it is applied to a large scale digitizer. In this paper, especially we propose simulation for error analysis with connection to angles measured at five control points which are needed to decide an appropriate model for calculating coordinates and optimal simulation for deciding the position of five control points to give the better coordinate accuracy. In this way, we realized the on-site calibration and on-site insurance of measurement accuracy with our appropriate model for calculating coordinates. The time required for on-site calibration is within 5 minutes and the average accuracy of 4m * 3m digitizer is about .+-.0.12mm.

• 제어로봇시스템학회논문지
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• 제17권2호
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• pp.102-107
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• 2011

In this paper we present cooperation of heterogeneous robot team, composed of a wheeled robot and a helicopter for localization and map building. This heterogeneous robot team can successfully fulfill task by combining the abilities of both robots than single robot because wheeled robot and helicopter have complementing ability. The scenario describes a tightly cooperative task, where the wheeled robot move carrying the helicopter and detect obstacles, if there are obstacles, helicopter take off for map building and land, then robot team move destination avoiding obstacles. We present PID controller for position control of helicopter and transformation algorithm to global coordinate from image pixel coordinate. Experimental result show that the proposed method is valid.

• Transactions on Control, Automation and Systems Engineering
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• 제3권4호
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• pp.236-241
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• 2001

Teach pendant is the most widely used means of robot teaching at present. Despite the difficulties of using the motion command buttons on the teach pendant, it is an economical, robust, and effective device for robot teaching task. This paper presents the development of a force/moment direction sensor named COSMO that can improve the teach pendant based robot teaching. Robot teaching experiment of a six axis commercial robot using the sensor is described where operator holds the sensor with a hand, and move the robot by pushing, pulling, and twisting the sensor in the direction of the desired motion. No prior knowledge of the coordinate system is required. The function of the COSMO sensor is to detect the presence f force and moment along the principal axes of the sensor coordinate system. The transducer used in the sensor is micro-switch, and this intuitive robot teaching can be implemented at a very low cost.

• 제어로봇시스템학회논문지
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• 제12권7호
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• pp.679-685
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• 2006

In this paper, development of an omni-directional mobile robot with rocker-bogie link structure is addressed. The overall mobile robot system consists of the robot mechanism with embedded control architecture, wireless communication with host graphic monitoring system, and the joy stick tole-controller. In the cluttered environment with various sizes of obstacles, the omni-directionality and the traversality are required for a mobile robot, so that the robot call go around or climb over the obstacles according to the size. The mobile robot mechanism developed in this paper has both of the omni-directionality and the traversality by 4 steerable driving wheels and the 2 additional passive omni-directional wheels linked with the rocker-bogie structure. The kinematic modeling for the mobile robot is described based on the well-known Sheth-Uicker convention and the instantaneous coordinate system.