• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.229-234
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• 2002

Under the hostile influence of the extreme space environmental conditions due to the deep space and direct solar flux, the thermal control in space applications is especially of major importance. There are tight temperature range restrictions for electro-optical elements while on the other hand there are low power consumption requirements due to the limited energy sources on the spacecraft. So, we usually have strong requirement of thermal and power control module in space applications. In this paper, the design concept of a thermal and power control module in the MSC(Multi-Spectral Camera) system which will be a payload on KOMPSATII is described in terms of H/W & S/W. This thermal and power control module, called THTM(Thermal and Telemetry Module) in MSC, resides inside the PMU(Payload Management Unit) which is responsible for the proper management of the MSC payload for controlling and monitoring the temperature insides the EOS(Electro-Optic System) and gathering all the analog telemetry from all the MSC sub-units, etc. Particularly, the designed heater controller has the special mode of "duty cycle" in addition to normal closed loop control mode as usual. THTM controls heaters in open loop according to on/off set time designed through analysis in duty cycle mode in case of all thermistor failure whereas it controls heaters by comparing the thermistor value to temperature based on closed loop in normal mode. And a designed THTM provides a checking and protection method against the failure in thermal control command using the test pulse in command itself.

• Earthquakes and Structures
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• 제13권2호
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• pp.165-176
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• 2017

Multi-Axial Testing System (MATS) is a 6-DOF loading system located at National Center for Research on Earthquake Engineering (NCREE) in Taiwan for advanced seismic testing of structural components or sub-assemblages. MATS was designed and constructed for a large variety of structural testing, especially for the specimens that require to be subjected to vertical and longitudinal loading simultaneously, such as reinforced concrete columns and lead rubber bearings. Functionally, MATS consists of a high strength self-reacting frame, a rigid platen, and a large number of servo-hydraulic actuators. The high strength self-reacting frame is composed of two post-tensioned A-shape reinforced concrete frames interconnected by a steel-and-concrete composite cross beam and a reinforced concrete reacting base. The specimen can be anchored between the top cross beam and the bottom rigid platen within a 5-meter high and 3.25-meter wide clear space. In addition to the longitudinal horizontal actuators that can be installed for various configurations, a total number of 13 servo-hydraulic actuators are connected to the rigid platen. Degree-of-freedom control of the rigid platen can be achieved by driving these actuators commanded by a digital controller. The specification and information of MATS in detail are described in this paper, providing the users with a technical point of view on the design, application, and limitation of MATS. Finally, future potential application employing advanced experimental technology is also presented in this paper.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권8호
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• pp.2529-2551
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• 2022

Visual servoing (VS) based on the Kalman filter (KF) algorithm, as in the case of KF-based image-based visual servoing (IBVS) systems, suffers from three problems in uncalibrated environments: the perturbation noises of the robot system, error of noise statistics, and slow convergence. To solve these three problems, we use an IBVS based on KF, African vultures optimization algorithm enhanced extreme learning machine (AVOA-ELM), and fuzzy logic (FL) in this paper. Firstly, KF online estimation of the Jacobian matrix. We propose an AVOA-ELM error compensation model to compensate for the sub-optimal estimation of the KF to solve the problems of disturbance noises and noise statistics error. Next, an FL controller is designed for gain adaptation. This approach addresses the problem of the slow convergence of the IBVS system with the KF. Then, we propose a visual servoing scheme combining FL and KF-AVOA-ELM (FL-KF-AVOA-ELM). Finally, we verify the algorithm on the 6-DOF robotic manipulator PUMA 560. Compared with the existing methods, our algorithm can solve the three problems mentioned above without camera parameters, robot kinematics model, and target depth information. We also compared the proposed method with other KF-based IBVS methods under different disturbance noise environments. And the proposed method achieves the best results under the three evaluation metrics.

• Nuclear Engineering and Technology
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• 제46권3호
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• pp.439-446
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• 2014

An amphibious inspection robot system (hereafter AIROS) is being developed to visually inspect the in-containment refueling storage water tank (hereafter IRWST) strainer in APR1400 instead of a human diver. Four IRWST strainers are located in the IRWST, which is filled with boric acid water. Each strainer has 108 sub-assembly strainer fin modules that should be inspected with the VT-3 method according to Reg. guide 1.82 and the operation manual. AIROS has 6 thrusters for submarine voyage and 4 legs for walking on the top of the strainer. An inverse kinematic algorithm was implemented in the robot controller for exact walking on the top of the IRWST strainer. The IRWST strainer has several top cross braces that are extruded on the top of the strainer, which can be obstacles of walking on the strainer, to maintain the frame of the strainer. Therefore, a robot leg should arrive at the position beside the top cross brace. For this reason, we used an image processing technique to find the top cross brace in the sole camera image. The sole camera image is processed to find the existence of the top cross brace using the cross edge detection algorithm in real time. A 5-DOF robot arm that has multiple camera modules for simultaneous inspection of both sides can penetrate narrow gaps. For intuitive presentation of inspection results and for management of inspection data, inspection images are stored in the control PC with camera angles and positions to synthesize and merge the images. The synthesized images are then mapped in a 3D CAD model of the IRWST strainer with the location information. An IRWST strainer mock-up was fabricated to teach the robot arm scanning and gaiting. It is important to arrive at the designated position for inserting the robot arm into all of the gaps. Exact position control without anchor under the water is not easy. Therefore, we designed the multi leg robot for the role of anchoring and positioning. Quadruped robot design of installing sole cameras was a new approach for the exact and stable position control on the IRWST strainer, unlike a traditional robot for underwater facility inspection. The developed robot will be practically used to enhance the efficiency and reliability of the inspection of nuclear power plant components.

• 한국컴퓨터정보학회논문지
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• 제24권12호
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• pp.25-33
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• 2019

본 논문은 목표한 방향으로 자유롭게 기동할 수 있는 새 크기의 물리기반 날갯짓 비행로봇 시뮬레이션을 위한 동역학적 신경망 컨트롤러를 생성하는 통합적인 진화연산 방법을 제시한다. 제안된 진화로봇 시스템은 날갯짓 비행의 추가적인 민첩성과 안정성을 위하여 Morphological Computation 개념을 응용한 간단한 날개 순응성 모델과 그와 통합된 Mechanosensory 정보를 활용한다. 역학적으로 불안정한 날갯짓 기동의 안정성 개선을 위해 로봇의 날개는 회전스프링으로 팔의 골격에 연결된 여러개의 패널들로 모델링되어, 새의 깃털에서 영감을 받은 단순한 형태의 날개 유연성을 시뮬레이션 하도록 설계되었다. 신경망 컨트롤러 역시 생물학적으로 의미있는 좌우대칭적 연결구조를 가짐과 동시에 최대의 진화연산 탐색 가능성을 위해 두 개의 fully-connected 신경망 모듈로 이루어지며, 이를 위한 센서정보로서 항법센서와 더불어 각 날개패널의 움직임 보들이 입력되어진다. 이러한 설계는 각 패널센서로 하여금 잠재적으로 신경망의 날갯짓 패턴 생성에 관여하게 함과 동시에, 날개에 가해지는 힘의 감지와 패널의 굽어짐으로 인한 날개 순응성으로부터 얻을 수 있는 비행의 민첩성과 안정성 향상을 동시에 유도할 수 있다. 본 시스템으로 진화된 날갯짓 로봇은 실시간으로 주어지는 목표방향으로의 효과적인 기동과 함께, 외부의 공기역학적 섭동에 대하여도 더욱 안정적인 비행을 유지함을 보여준다.

• 한국환경보건학회지
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• 제28권4호
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• pp.6-11
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• 2002

3.3'-Dichlorobenzidine(DCB) has be shown carcinogenic in several animals, and the development of non-invasive biomonitoring method in workers exposed with it is a very important subject. DNA adduct is a good biomarker for biomonitoring about carcinogens exposure, and lymphocytes is a good non-invasive samples. So we studied to analyze metabolites in blood lymphocytes of female Sprague-Dawley rats exposed orally with DCB(20, 30, and 40 mg/kg wt.) for 3 weeks. For analysis of them, we isolated DNA adducts from blood lymphocytes by using the enzymes method in /sup 32/P-postlabeling, and measured them by using gas chromatography/mass spectrometry-selected ion monitoring(GC/MS-SIM). 4-aminobiphenyl and phenanthrene-d/sub 10/ were added as internal standard for blank sample. Standard metabolites of DCB were synthesized with using pyridine and acetic acid which were promoter and controller in acetylation of DCB. And they were used for calibration curve. Our results showed two kinds of metabolites in DNA adducts of blood lymphocytes. They were N-acetyl 3,3'-dichlorobenzidine(acDCB) and N,N'-diacetyl 3,3'-dichiorobenzidine(di-acDCB ). They were combined with DNA at the same time as an acetyl of it was removed. So we measured DCB and acDCB for two kinds of metabolites in DNA adducts of blood lymphocytes. Our results showed the levels of DCB were 1.46∼2.26 times more than that of acDCB. And also the levels of metabolites in 20, 30 and 40 mg/kg wt. were gradually increased with going days from 1st to 3rd week. They are 1.66, 1.38 and 0.90 times in total metabolites, 1.76, 1.49 and 1.02 times in DCB, and 1.51, 1.22 and 1.28 times in acDCB. In conclusion, the results of this study showed DCB exposed to rats formed DNA adduct in blood lymphocytes after acetylated to N-acetyl 3.3'-dichloro benzidine(acDCB) and N,N'-diacetyl 3,3'-dichlorobenzidine(di-acDCB), and they could be analyzed by us ing gas chromatography/mass spectrometry-selected ion monitoring(GC/MS-SIM).

• Journal of Astronomy and Space Sciences
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• 제29권4호
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• pp.381-387
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• 2012

The planetary exploration rover executes various missions after moving to the target point in an unknown environment in the shortest distance. Such missions include the researches for geological and climatic conditions as well as the existence of water or living creatures. If there is any obstacle on the way, it is detected by such sensors as ultrasonic sensor, infrared light sensor, stereo vision, and laser ranger finder. After the obtained data is transferred to the main controller of the rover, decisions can be made to either overcome or avoid the obstacle on the way based on the operating algorithm of the rover. All the planetary exploration rovers which have been developed until now receive the information of the height or width of the obstacle from such sensors before analyzing it in order to find out whether it is possible to overcome the obstacle or not. If it is decided to be better to overcome the obstacle in terms of the operating safety and the electric consumption of the rover, it is generally made to overcome it. Therefore, for the purpose of carrying out the planetary exploration task, it is necessary to design the proper suspension system of the rover which enables it to safely overcome any obstacle on the way on the surface in any unknown environment. This study focuses on the design of the new double 4-bar linkage type of suspension system applied to the Korea Aerospace Research Institute rover (a tentatively name) that is currently in the process of development by our institute in order to develop the planetary exploration rover which absolutely requires the capacity of overcoming any obstacle. Throughout this study, the negative moment which harms the capacity of the rover for overcoming an obstacle was induced through the dynamical modeling process for the rocker-bogie applied to the Mars exploration rover of the US and the improved version of rocker-bogie as well as the suggested double 4-bar linkage type of suspension system. Also, based on the height of the obstacle, a simulation was carried out for the negative moment of the suspension system before the excellence of the suspension system suggested through the comparison of responding characteristics was proved.

• 디지털융복합연구
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• 제12권10호
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• pp.337-343
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• 2014

PRT(Personal Rapid Transit)는 유형 또는 무형의 전용궤도에서 자동으로 승객의 요구에 따라 출발지에서 목적지까지 최적의 경로로 논스톱 운행하며, 높은 접근성과 프라이버시 보장 등 자가용 수준의 서비스 제공이 가능한 대중교통수단으로서, 최근 새로운 미래교통시스템으로 재조명받고 있다. 본 논문에서는 PRT 시스템의 연계 운행 효율성 극대화를 목표로 수직이송장치를 연동제어하는 PRT 운행제어시스템의 제어모듈 및 시뮬레이터의 설계 및 시험결과를 제시하였다. 수직이송장치부의 PLC는 운영제어센터 또는 역제어시스템과의 인터페이스를 위해 Modbus 프로토콜을 적용하여 설계되었으며, 원격제어시스템으로부터 명령을 전달받아 동작하는 자동모드와 수직이송장치에 설치된 센서검지 상태에 따라 독립적으로 동작하는 수동모드로 구성하였다. 또한, 실제 차량이 운행하는 환경에서 가상의 차량운행 시나리오를 적용하여 실제 차량과 가상 차량을 혼합하여 운행할 수 있는 3D 그래픽 기반 PRT 운영제어 시뮬레이터를 구현하였다.

• 한국ITS학회 논문지
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• 제7권5호
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• pp.77-89
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• 2008

자전거도로가 설치된 교차로 빛 횡단도로에서 자전거, 차량 및 보행자 간에 상충이 발생하게 된다. 이와 같이 자전거 도로와 여타 교통류가 교차되는 구간에서 자전거와 자동차, 자전거와 보행자와의 상충을 분리해주어야 하는데, 이런 방법 중 하나가 자전거전용신호라고 할 수 있다 자전거도로 시설 및 이용자 특성조사에 따르면 자전거도로가 횡단보도와 연 계하여 설치되어 있고, 자전거이용자 대부분이 횡단보도신호를 이용하고 있으며, 횡단보도시간 내에 횡단을 종료하는 것으로 조사되었다. 따라서 횡단보도와 자전거도로가 인접된 자전거횡단도로에서는 보행신호등과 연계한 운영방안 즉, 영국의 TOUCAN Crossing 형태의 적용이 제안된다. 이와 같은 자전거전용신호 운영체계는 현재 자전거횡단도로의 위치가 횡단보도와 인접하여 설치되어 있고, 대부분의 자전거이용자들이 보행신호에 따라 도로를 횡단하고 있으며, 보행선호시간동안 횡단할 수 있기 때문이다. 반면에 자전거횡단도로가 보행도로와 이격되어 설치된 경우 및 자전거의 통행속도 등을 고려하여 전용도로 형태로 자전거도로가 설치된 경우에는 차량신호와 연계한 자전거신호등 형태 (3색 등화체계)가 제안된다. 이와 같은 자전거신호등의 운영형태는 기존 자전거도로 시설과 자전거이용자의 도로횡단특성을 수용하고, 교통 신호제어기의 기능변경 없이 신호시간의 조정만으로 적용이 가능한 이점이 있다.

• 융합신호처리학회논문지
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• 제21권1호
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• pp.21-28
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• 2020

본 논문에서는 새로운 형태의 전동 외발 손수레를 제안하였다. 제안된 전동 외발 손수레는 작업 동작을 감지하여 작업자의 의도에 따라 안전하고 균형을 잃지 않도록 하면서 자동으로 외발 손수레를 이동시킬 수 있도록 해 준다. 작업자가 손수레의 손잡이를 잡고 위 아래로 기울이면 외발 손수레에 장착된 방위각 센서를 이용하여 전후 방향의 각도인 피치각을 감지하고 이를 전후진 이동 의도로 간주하여 각도의 크기에 비례하는 속력으로 손수레의 바퀴를 가감속 제어하여 전후진시킨다. 또한 기존 손수레와 달리 적재함에도 추가의 자유도를 부가하여 회전할 수 있도록 하였고, 작업 중 손수레가 좌우 방향으로 기울어질 때 기울기인 롤각을 감지하고 이를 기반으로 하여 적재함이 항상 지면과 수평을 유지할 수 있도록 위치 제어하여 작업자가 손수레의 균형을 잃지 않고 안전하고 쉽게 손수레를 운전할 수 있도록 해 준다. 농업 현장이나 산업 현장에서 실제로 사용할 수 있도록 DC 모터와 인휠모터, 모터 드라이버, 2축 방위각 센서와 저가의 마이크로 컨트롤러를 사용하여 경제적이고 효율적인 제어 시스템을 구성하고 기구부 설계 제작도 수행하였다. 또한 피치각의 변화만 있는 경우, 롤각의 변화만 있는 경우, 그리고 피치각과 롤각이 동시에 변화하는 경우에 대한 실험을 통해 개발된 전동 외발 손수레의 안정성과 유용성을 검증하였다.