Design of Mobility System for Ground Model of Planetary Exploration Rover

Kim, Younkyu,Eom, Wesub,Lee, Joo-Hee,Sim, Eun-Sup 한국우주과학회 2012 Journal of Astronomy and Space Sciences Vol.29 No.4

In recent years, a number of missions have been planned and conducted worldwide on the planets such as Mars, which involves the unmanned robotic exploration with the use of rover. The rover is an important system for unmanned planetary exploration, performing the locomotion and sample collection and analysis at the exploration target of the planetary surface designated by the operator. This study investigates the development of mobility system for the rover ground model necessary to the planetary surface exploration for the benefit of future planetary exploration mission in Korea. First, the requirements for the rover mobility system are summarized and a new mechanism is proposed for a stable performance on rough terrain which consists of the passive suspension system with 8 wheeled double 4-bar linkage (DFBL), followed by the performance evaluation for the mechanism of the mobility system based on the shape design and simulation. The proposed mobility system DFBL was compared with the Rocker-Bogie suspension system of US space agency National Aeronautics and Space Administration and 8 wheeled mobility system CRAB8 developed in Switzerland, using the simulation to demonstrate the superiority with respect to the stability of locomotion. On the basis of the simulation results, a general system configuration was proposed and designed for the rover manufacture.

달 표면 무인로버 임무설계 도구 개발 및 적용 사례

김연규(Younkyu Kim),류동영(Dong Young Rew) 한국항공우주학회 2022 한국항공우주학회 학술발표회 논문집 Vol.2022 No.11

Robust Optimal Design of a Six-Bar Linkage-Based Finger Clamping Unit for High Durability

SangGyun Kim,Kyeongtae Lim,Younkyu Kim,TaeWon Seo 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.4

A finger clamping unit (FCU) is a clamp for fixing a thin panel through a toggle mechanism in which the torque input is amplified. Previous studies optimized the clamping range (range of thickness of a panel that can be clamped) using a compliant link. Thereby, panels of various thicknesses could be clamped. However, a problem occurred in the durability because of the optimization to increase only the clamping range. The most vulnerable part, the compliant link, was damaged. In this study, durability is improved by replacing the linear slide joint (the mechanical element of the FCU) with a curved slide joint from another study. A static analysis of the new FCU is conducted. In addition, optimization is performed to reduce the force applied to the compliant link using the Taguchi method in a simulated environment. The result is expressed as a three-dimensional plot representing the behavior of the FCU. As a result of optimization, durability has increased significantly. furthermore, the clamping range is also increased slightly, and the overall size of the FCU is decreased. In addition, the increase in durability was greater when subjected to a large force than when subjected to a small force. When the penal thickness is 2mm, the force applied to the compliant link is decreased by 15.85%.

생명유지기술의 해저 유인시스템 적용

김연규(Younkyu Kim),이주희(Joohee Lee),류동영(Dong Young Rew) 한국항공우주학회 2023 한국항공우주학회 학술발표회 논문집 Vol.2023 No.11

Emergent Vertebral Artery Embolization during C12 Screw Fixation for Rheumatoid Arthritis

Dong Hee Kim,Younkyu Jang,Kum Whang,Jong-Yeon Kim,Sungmin CHO 대한신경손상학회 2021 Korean Journal of Neurotrauma Vol.17 No.2

The subaxial screw fixation technique is commonly used for fixation in a wide range of cervical diseases, including traumatic, degenerative, and neoplastic diseases, rheumatoid arthritis (RA), and spondyloarthropathy. Although it is regarded as a relatively safe procedure, several complications may be encountered during surgery, such as vertebral artery (VA) and nerve root injuries, facet violation, and mass fracture. We report a case of endovascular embolization after VA injury during a high cervical spinal surgery. A 48-year-old woman was scheduled for C-1-2-3 posterior fixation. Plain radiography of the cervical spine revealed a severely unstable state. During dissection around the C1 lateral mass on the right side, sudden brisk arterial bleeding was observed. On vertebral angiography, flow voiding was noted above the right V3 portion. After checking patent collateral flow from the contralateral VA, routine coil embolization was performed to pack the V3 segment. Iatrogenic vascular injuries due to spinal surgery are rare but serious complications. For patients with RA, we recommend careful preoperative evaluation before a high cervical surgical procedure to avoid iatrogenic VA injury and endovascular interventions that are safe and effective in the diagnosis and treatment of such vascular injuries.

해저거주시설 모사 지상실험모듈 개발 요구사항 분석

이주희,김연규,이종원,Joohee Lee,Younkyu Kim,Jongwon Lee 한국우주과학회 2022 우주기술과 응용 Vol.2 No.3

There are various systems that allow humans to safely maintain their space exploration missions and lives in completely different environments, such as the International Space Station, the Moon (the closest celestial body to Earth), and Mars (the only planet in the solar system for manned mission in the 2030s). Among them, when it comes to maintaining the basic breathing of humans, the human life support air management system is a key device system. Such an air management system can be used not only for space exploration but also for undersea bases and submarines on Earth where humans reside. The air management system basically consists of an oxygen generation system, a carbon dioxide removal system, and a harmful substance removal system. In this paper, in order to develop an air management system that can be used in an underwater residential platform, the development requirements of a ground test module to be used as an experimental facility were analyzed.

유인 우주탐사용 생명유지시스템 개발 동향

이종원,김연규,이주희,Lee, Jongwon,Kim, Younkyu,Lee, Joohee 한국우주과학회 2021 우주기술과 응용 Vol.1 No.1

인간이 지구를 벗어난 우주 공간, 태양계 내의 천체(예, 달, 화성 등) 등에서 안전하게 생활하기 위해서는 반드시 환경제어 및 생명유지시스템 기술이 필요하다. 생명유지시스템은 일반적으로 공기관리시스템, 물정화시스템, 폐기물관리시스템 등으로 구성되며, 우주공간의 밀폐된 주거지에서 인간의 호흡 활동과 일상생활이 가능하도록 해준다. 본 논문에서는 우선 미국 항공우주국(NASA) 주도로 개발되어 온 생명유지시스템의 개발 동향을 소개하였다. 그리고, 현재 국제우주정거장(ISS)에서 운용 중인 생명유지시스템의 현황에 대하여 살펴보고, 국내 개발 동향도 조망해 보았다. Environmental Control & Life Support System (ECLSS) technology is essential for humans to live safely in space other than on Earth and celestial bodies (ex, Moon, Mars etc.) in our solar system. Life support systems generally consist of Air Management System (AMS), Water Recovery System (WRS), and Waste Management System (WMS), and it can enable humans to breathe and live in enclosed dwellings in outer space. First, this paper described the development trends of life support systems that have been developed under the leadership of NASA. In addition, we introduced the current development status of life support system in operation on the International Space Station (ISS) and prospected the development trends in Korea.

A Study on the Optimization of the Package of Reactor Internal Vessels of Nuclear Power Plants Using Demplus

Sunkyu Park,Taewoong Lee,Seongmin Jo,Younkyu Kim,Seokyoung Ahn 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1

As the decommissioning of nuclear power plants progresses, interest in the inevitably generated radioactive waste is also increasing. Especially, because the containers of ILW packages are significantly more expensive than the containers of LLW packages, the special attention should be focused on minimizing the number of the containers of ILW packages. The radiation dose limit for packaging of ILW shall not exceed 2 mSv/h and 0.1 mSv/h on contact and at 2 m, respectively in South Korea. Meanwhile, The DEMplus provides various environmental geometry and all properties such as materials, absorptions, and reflections and the estimation of the radiation dose rates is based on the radiation interactions of the designed 3D geometry model. With the consideration of the radiation dose rate by using DEMplus and its strategy of packaging and cutting plan, the number of containers for ILW packages generated from decommissioning of Reactor Vessel Internal (RVI) of a nuclear power plant that has been in operation for decades was optimized in this paper. The modular shielded containers (MSC) with shielding inserted were used for radioactive wastes that require shielded packaging. In order to verify the accuracy of the estimated radiation dose rate by using DEMplus, the estimated results were compared with those obtained using MicroShield. The trends of the estimated radiation dose rates using DEMplus and the estimation of MicroShield were similar to each other. The results of this study demonstrated the feasibility of using DEMplus as a means of estimating the radiation dose limit in packaging plan of the radioactive waste.

우주 생명유지시스템 필요성 및 연구동향

이주희(Joohee Lee),류동영(Dong Young Rew),이종원(Jongwon Lee),김연규(Younkyu Kim) 한국항공우주학회 2022 한국항공우주학회 학술발표회 논문집 Vol.2022 No.4