• 대한기계학회논문집A
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• 제31권5호
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• pp.609-616
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• 2007

Palletizing is necessary to promote the efficiency of storage and shipping tasks. These are, however some of the most monotonous, heavy and laborious tasks in the factory. Therefore many types of robot palletizing systems have been developed, but many robot motion commands still depend on the teaching pendent. That is, an operator inputs the motion command lines one by one. It is very troublesome, and most of all, the user must know how to type the code. That is why we propose a new GUI (Graphic User Interface) Palletizing System. To cope with this issue, we proposed a 'PLP' (Pallet Loading Problem) algorithm, Fast Algorithm and realize 3D auto-patterning visualization interface. Finally, we propose the robot palletizing simulator. Internally, the schematic of this simulator is as follows. First, an user inputs the physical information of object. Second, simulator calculates the optimal pattern for the object and visualizes the result. Finally, the calculated position data of object is passed to the robot simulator. To develop the robot simulator, we use an articulated robot, and analyze the kinematics and dynamics. Especially, All problem including thousands of boxes were completely calculated in less than 1 second and resulted in optimal solutions by the Fast Algorithm.

• 대한원격탐사학회지
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• 제24권3호
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• pp.223-233
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• 2008

In the mid 90's, the U.S. government released images acquired by the first generation of photo reconnaissance satellite missions between 1960 and 1972. The Declassified Intelligent Satellite Photographs (DISP) from the Corona mission are of high quality with an astounding ground resolution of about 2 m. The KH-4A panoramic camera system employed a scan angle of $70^{\circ}$ that produces film strips with a dimension of $55\;mm\;{\times}\;757\;mm$. Since GPS/INS did not exist at the time of data acquisition, the exterior orientation must be established in the traditional way by using control information and the interior orientation of the camera. Detailed information about the camera is not available, however. For reconstructing points in object space from DISP imagery to an accuracy that is comparable to high resolution (a few meters), a precise camera model is essential. This paper is concerned with the derivation of a rigorous mathematical model for the KH-4A/B panoramic camera. The proposed model is compared with generic sensor models, such as affine transformation and rational functions. The paper concludes with experimental results concerning the precision of reconstructed points in object space. The rigorous mathematical panoramic camera model for the KH-4A camera system is based on extended collinearity equations assuming that the satellite trajectory during one scan is smooth and the attitude remains unchanged. As a result, the collinearity equations express the perspective center as a function of the scan time. With the known satellite velocity this will translate into a shift along-track. Therefore, the exterior orientation contains seven parameters to be estimated. The reconstruction of object points can now be performed with the exterior orientation parameters, either by intersecting bundle rays with a known surface or by using the stereoscopic KH-4A arrangement with fore and aft cameras mounted an angle of $30^{\circ}$.

• Transactions on Control, Automation and Systems Engineering
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• 제4권1호
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• pp.23-31
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• 2002

We proposed a concept of a desktop micro device factory for visually servoed teleoperated microassembly assisted by a virtual reality (VR) interface. It is composed of two micromanipulators equipped with micro tools operating under a light microscope. First a manipulator, control method for the micro object to follow a planned trajectory in pushing operation is proposed undo. vision based-position control. Then, we present the cooperation control strategy of the micro handling operation under vision-based force control integrating a sensor fusion framework approach. A guiding-system based on virtual micro-world exactly reconstructed from the CAD-CAM databases of the real environment being considered is presented for the imprecisely calibrated micro world. Finally, some experimental results of microassembly tasks performed on millimeter-sized components are provided.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.975-980
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• 2004

Positioning system is widely used for many practical applications. This system requires a good controller to achieve high accuracy and fast response with simple and self-adjustable design. In order to satisfy the above requirements, a new practical controller for positioning systems, namely nominal characteristic trajectory following (NCTF) controller with PI compensator, has been proposed. However, the effect of actuator saturation can not be completely compensated for integrator windup when the object parameters vary. This paper presents a method to improve the NCTF controller by overcoming the problem of integrator windup by adopting a fuzzy system. The improvement of the NCTF controller is evaluated through simulation using a rotary positioning system. The simulation result has demonstrated the effectiveness of the compensated NCTF in overcoming the problem of integrator windup.

• 전자공학회논문지A
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• 제32A권2호
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• pp.31-37
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• 1995

A ray-based approach is developed to calculate the scattering from inhomogeneous dielectric objects. This approach is a natural extension of the "shooting and bouncing ray(SBR)" technique developed earlier for calculating the radar cross section of cavity structures and complex targets. In this formulation, a dense grid of rays representing the incident field is shot toward the scatterer. The curved trajectory, amplitude, phase and polarization of the ray fields inside the inhomogeneous object are computed numerically based on the laws of geometrical optics. The contributions of the exting rays to the exterior scattered field are then calculated by using the equivalence principle in conjunction with " a ray-tube integration" scheme. The ray-based approach is applied for the effect of an arcjet plasma plume on satellite reflector performance and backscattering from inhomogeneous objects.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2006년도 춘계학술발표대회
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• pp.75-78
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• 2006

이 논문은 이동 차량의 궤적 정보 관리를 통한 물류 관리 시스템을 제안한다. 물류 시스템은 물류 센터에서 차량과 배송 물품의 위치를 지속적으로 모니터링하고, 이와 연관된 서비스를 제공하는 시스템이다. 따라서 물류 차량의 실시간 위치 정보관리가 필수적이다. 제안된 시스템은 기존의 지리 정보와 더불어 실세계 모바일 환경에서 물류 배송 정보의 효율적 관리 기능을 지원한다. 또한 효과적인 물류 이동 경로 관리 및 검색을 위하여 시공간 색인 기법을 적용하였다. 제안된 시스템은 물류 관리 뿐만 아니라 이와 유사한 서비스를 제공하는 차량 추적 시스템, 위치 기반 서비스 등과 같이 모바일 환경에서 실시간으로 변화하는 관리 대상 객체의 위치 정보를 관리하는 분야에 적용 가능하다.

• 한국공간정보시스템학회:학술대회논문집
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• 한국공간정보시스템학회 2005년도 추계학술대회
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• pp.169-174
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• 2005

위치기반서비스(LBS)에서는 사람, 차량과 같은 이동체의 위치 정보를 획득하며, 이동객체 DBMS의 개발로 이동체가 움직인 궤적 정보를 효율적으로 저장 관리할 수 있다. 이동객체 DBMS에 저장된 이동체가 실제 움직인 과거 궤적정보는 다양한 형태로 가공되어 활용이 가능하다. 본 논문에서는 이동체의 과거 궤적정보를 이용하여 경로 안내를 위한 경로 산출 방법에 대하여 제안한다. 기존의 경로 안내는 교통정보 수집 장치를 통해 획득한 교통 정보를 이용하여 경로를 산출하는 방식이 많이 사용되고 있어, 교통 정보가 없는 곳에서는 단순 초행길 안내 수준이다. 그러나, 본 논문에서 제안하는 방법은 고비용이 소요되는 교통정보수집장치가 없는 곳에 대해서도 과거 차량의 움직인 궤적정보를 이용하여 보다 효율적인 경로 안내를 할 수 있는 장점이 있다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2016년도 하계학술대회
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• pp.309-312
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• 2016

최근 실세계에 존재하는 물체의 3차원 형상과 색상을 디지털화하는 3차원 객체 복원에 대한 관심이 날로 증가하고 있다. 3차원 객체 복원은 영상 획득, 영상 보정, 점군 획득, 반복적 점군 정합, 무리 조정, 3차원 모델 표현과 같은 단계를 거처 통합된 3차원 모델을 생성한다. 그 중 반복적 점군 정합 방법은 카메라 궤적의 초기 값을 획득하는 방법으로서 무리 조정 단계에서 전역 최적 값으로의 수렴을 보장하기 위해 중요한 단계이다. 기존의 반복적 점군 정합 (iterative closest points) 방법에서는 시간이 지남에 따라 누적된 궤적 오차 때문에 발생하는 객체 표류 문제가 발생한다. 본 논문에서는 이 문제를 해결하기 위해 색상 영상에서 SIFT 특징점을 획득하고 3차원 점군을 얻은 뒤 가중치를 부여함으로써 점 군 간의 더 정확한 정합을 수행한다. 실험결과에서 기존의 방법과 비교하여 제안하는 방법이 절대 궤적 오차 (absolute trajectory error)가 감소하는 것을 확인 했고 복원된 3차원 모델에서 객체 표류 현상이 줄어드는 것을 확인했다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.422-427
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• 2006

This paper presents force-feedback control performance of a haptic device in virtual environment of minimally invasive surgery(MIS). As a first step, based on an electrorheological(ER) fluid and spherical geometry, a new type of master device is developed and integrated with a virtual environment of MIS such as a surgical tool and human organ. The virtual object is then mathematically formulated by adopting the shape retaining chain linked(S-Chain) model. After evaluating reflection force, computational time, and compatibility with real time control, the virtual environment of MIS is formulated by interactivity with the ER haptic device in real space. Tracking control performances for virtual force trajectory are presented in time domain, and theirtrackingerrorsareevaluated.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.894-897
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• 2004

In this paper, we address a position control scheme for a stage system, which is levitated and driven by electric magnetic actuators. This consists of a levitating object (called platen) with 4 permanent magnetic linear synchronous motors in parallel. Each motor generates vertical force for suspension against gravity and propulsion force horizontally as well. This stage can generate six degrees of freedom motion by the vertical and horizontal forces. Dynamic equations of the stage system are derived based on Newton-Euler method and its special Jacobian matrix describing a relation between the Joint velocity and platen velocity is done. There are proposed two control schemes for positioning, which are Cartesian space controller and Joint space controller. The control performance of the Cartesian space controller is better than the Joint space controller in task space trajectory while the Joint space controller is simpler than the Cartesian space controller in controller realization.