• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.180-187
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• 2002

Recently, there has been an increase in the demand to enhance the intelligence of construction equipment and systems. Especially for semiautonomous and autonomous systems that have great potential for impact on the construction industry, artificial intelligence approaches are required to generate instructions and plans necessary to perform tasks in dynamically changing environments on their own. The framework for an intelligent earthwork system (IES) is suggested in this paper. It generates a plan automatically for construction equipment and provides a means of cooperation between construction equipment seamlessly. This paper describes the system architecture, control strategy, task planning method, and resource allocation method for IES.

• Journal of The Korean Institute of Defense Technology
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• v.5 no.3
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• pp.18-28
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• 2023

The threat of drones is widely occurring not only in the military field but also for important national facilities such as airports and nuclear power plants. Drones are very diverse in types and control methods, so it is not easy to have a uniform defense method and system, and with the development of drone technology, the war paradigm using drones as weapons is also changing. In particular, advances in drone technology are improving the efficiency and accuracy of reconnaissance and attack missions. Nevertheless, it is very difficult to secure research cases on military operation of drones due to difficulties in obtaining information on military operations. Therefore, in this study, we try to create basic data that can effectively establish a plan for performing reconnaissance and attack missions by deriving each operational aspect through analysis of operation cases of reconnaissance and attack drones.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.05a
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• pp.198-201
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• 2021

무인 항공기(UAV, Unmanned Aerial Vehicles)는 높은 기동성을 가지며 설치 비용이 저렴하다는 이점이 있어 홍수, 지진 등의 재난 재해 감시 시스템에 이용되고 있다. 재난 재해 감시 시스템에서 UAV는 지상에 위치한 사물인터넷(IoT, Internet of Things) 기기로부터 데이터를 수집하는 임무를 수행하기 위해 계획된 항로를 따라 비행한다. 이때 UAV가 정상 경로로 비행하기 위해서는 실시간으로 GPS 위치 확인이 가능해야 한다. 만일 UAV가 계산한 현재 위치의 GPS 정보가 잘못될 경우 비행경로에 대한 통제권을 상실하여 임무 수행을 완료하지 못하는 결과가 초래될 수 있다는 취약점이 존재한다. 이러한 취약점으로 인해 UAV는 공격자가 악의적으로 거짓 GPS 위치 신호를 전송하는GPS 스푸핑(Spoofing) 공격에 쉽게 노출된다. 본 논문에서는 신뢰할 수 있는 시스템을 구축하기 위해 지상에 위치한 기기가 송신하는 신호의 세기와 GPS 정보를 이용하여 UAV에 GPS 스푸핑 공격 여부를 탐지하고 공격당한 UAV가 경로를 이탈하지 않도록 대응하기 위해 연합학습(Federated Learning)을 이용하는 방안을 제안한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.2
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• pp.354-361
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• 2018

This paper describe the Lateral Navigation algorithm design and verification that implementation on Mission Computer's OFP for Korean Utility Helicopter(KUH) instead of Auto Flight Control System(AFCS) Vehicle Management System. The LNAV function transmits Roll command into the AFCS System. The Roll command value will be calculated by control algorithms in MC. The Operational Flight Program(OFP) shall use for its calculations different measurements of the aircraft's attitude and place. Using these inputs, the OFP will translate a navigational demand(for example-to perform the selected flight plan) into Roll commands to the autopilot. By conducting integration test using SIL and ground test, flight test, it is confirmed that the introduced algorithm meets the requirements of the Mission Equipment Package(MEP) system. LNAV function is verified through the System Integration Laboratory(SIL) test, ground and flight test.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.28.3-28.3
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• 2009

과학기술위성 3호는 2007년 6월에 사업착수를 시작하여, 동년 8월 시스템요구사항검토회의(SRR)를 통해 임무 요구사항을 도출하였고, 동년 12월에 시스템기본설계검토회의(SDR)과 2008년 9월 시스템예비설계검토회의(PDR)를 개최하여 시험인증모델(EQM, Engineering& Qualification Model) 제작을 시작하여, 납품을 완료하고 ETB(Engineering Test Bed)상에서 유닛의 기능 시험 및 접속시험, 그리고 환경시험을 수행을 완료하였다. 또한 열구조모델 (STM, Structure and Thermal Model)도 제작을 완료하고 발사환경시험과 열평형 환경시험을 완료하였다. 이와같이 시험인증모델 및 열구조모델에 대한 지상에서의 시험과 검증이 완료된 시험결과를 바탕으로 2009년 9월 상세설계를 완료하고 비행모델 제작에 착수할 예정이다. 이 논문에서는 과학기술위성 3호의 시험인증모델에 대한 시험의 목적, 종류 그리고 검증에 대한 결과 그리고 향후 계획에 대해 발표하고자 한다. 참고로 과학기술위성 3호는 주탑재체인 다목적적외선영상시스템(MIRIS)은 우리 은하계의 근적외선 관측, 우주 배경복사 관측 및 지구 지표면의 적외선 영상 획득을 임무로 하고 있고, 부탑재체인 초소형 영상 분광기(COMIS)는 한반도 지역의 다중 스펙트럼 영상을 획득함으로써 대기관측 및 환경감시의 임무를 가지고 있다.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.55.3-55.3
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• 2019

우리나라 최초의 우주탐사 프로그램인 Korea Pathfinder Lunar Orbiter (KPLO)는 1년의 임무기간동안 달과 달 주변의 우주환경에 대한 과학탐사 임무를 수행할 예정이다. 이를 위해서 1개에 기술 검증장비와 고해상도 카메라를 포함한 5개의 과학장비를 탑재할 예정이다. 이 중 고해상도 카메라인 LUTI(LUnar Terrain Imager)와 국내에서 개발한 3개의 과학탑재체(KGRS;감마선분광기, KMAG;자기장측정기, PolCam;광시야 편광카메라)가 획득한 과학자료는 일정기간(통상 1년)동안 비공개로 검보정이 이루어진 후 일반에게 공개(Public release)할 예정이다. 이러한 과학자료의 공개와 관리를 위해서 한국항공우주연구원은 KPLO 심우주 지상시스템 내에 과학자료의 공개 및 관리를 위한 KARI Planetary Data System(KPDS)을 개발하고 있다. KPDS는 미국 NASA의 PDS에서 개발하여 유럽, 일본 등에서 이미 행성탐사 과학자료의 표준으로 활용하고 있는 PDS4 표준을 준수하는 과학자료를 제공할 것이다. 본 발표를 통해서 KPDS의 운영개념과 과학자료 관리계획, 그리고 KPDS의 개발현황을 천문학계와 공유하여 KPLO에 의해서 획득된 과학자료가 많은 과학자들이 활용하여 높은 과학적 성과를 낼 수 있기를 기대한다.

• Journal of Aerospace System Engineering
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• v.18 no.1
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• pp.11-20
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• 2024

In the recent era of NewSpace, unlike high-reliability satellites of the past, low-reliability satellites are being developed and mass-produced at a lower cost to launch constellations satellites. To achieve cost-effective cluster satellite development, satellite users and developers need to assess the feasibility of maintaining mission performance over the expected lifespan when cluster satellites are launched. Plans for replacements due to random failures should also be established to maintain performance. This study proposed a method for assessing system reliability and availability to maintain mission performance and establish replacement strategies for Earth observation constellation satellites. In this study, a constellation reliability and availability model considering mission performance required for a satellite constellation, situations of satellite backup, and additional ground backups was established. The reliability model was structured based on the concept of a k-out-of-n system and the availability model used a Markov chain model. Based on the proposed reliability model, the minimum number of satellites required to meet mission requirements was defined and satellites needed in orbit during the required mission period to satisfy mission reliability were calculated. This research also analyzed the number of spare satellites in orbit and on the ground required to meet the desired availability during required service period through availability analysis.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.701-704
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• 2010

In studying an autonomous navigation technique of UUV(Unmaned Underwater Vehicle), one of the many fundamental techniques is to plan a 3D path to complete the mission via realtime information received by sonar showing landscapes and obstacles. The simulation system is necessary to verify the algorithm in researching and developing 3D path planning of UUV. It is because 3D path planning of UUV should consider guide control, the dynamics, ocean environment, and search sonar models on the basis of obstacle avoidance technique. The simulation system developed in this paper visualizes the UUV's movement of avoiding obstacles, arriving at the goal position via waypoints by using C++ and OpenGL. Plus, it enables the user to setup the various underwater environment and obstacles by a user interface. It also provides a generalization that can verify path planning algorithm of UUV studied in any developing environment.

• Journal of Aerospace System Engineering
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• v.14 no.5
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• pp.9-17
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• 2020

Mobile robots, including UAVs perform missions with limited fuel. Therefore, the energy-aware path planning is required to maximize efficiency when the robot is operated for a long time. In this study, we estimated the power consumption for each maneuver of a quadcopter UAV in the 3D environment and applied to the cost functions of D^⁎ Lite. The simulations were performed in a 3D environment that is similar to the industrial sites. The efficiency of path generation was high when the energy-aware path planning with simplified heuristic was applied. In addition, the energy-aware path was generated 19.3 times faster than the shortest path with a difference within 3.2%.

• Journal of Advanced Navigation Technology
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• v.21 no.5
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• pp.443-449
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• 2017

Swarm of low-cost UAVs for search mission has benefit in the sense of rapid search compared to use of single high-end UAV. As the number of UAVs forming swarm increases, not only the time for the mission planning increases, but also the system to operate UAVs has excessive burden. This paper addresses a decentralized area search algorithm adequate for multiple UAVs which takes advantages of flexibility, robustness, and simplicity. To down the cost, it is assumed that each UAV has limited ability: close-communication, basic calculation, and limited memory. In close-communication, heath conditions and search information are shared. And collision avoidance and consensus of next search direction are then done. To increase weight on un-searched area and to provide overlapped search, the score function is introduced. Performance and operational characteristics of the proposed search algorithm and mission planning logic are verified via numerical simulations.