Study on a Suspension of a Planetary Exploration Rover to Improve Driving Performance During Overcoming Obstacles

엄위섭,김윤규,이주희,최기혁,심은섭 한국우주과학회 2012 Journal of Astronomy and Space Sciences Vol.29 No.4

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.

대기권 재진입 기준궤도 해석

엄위섭,이대우,조겸래 제어로봇시스템학회 1999 제어로봇시스템학회 각 지부별 자료집 Vol.1999 No.12

Study on an 8-Wheel Suspension to Enhance the Hill-Climbing Performance for a Planetary Exploration Rover

엄위섭,이주희,공현철,최기혁 한국우주과학회 2014 Journal of Astronomy and Space Sciences Vol.31 No.4

Planetary exploration rovers are likely to make a trip on a winding and sloping road of irregular surfaces to the destinationin order to accomplish scientific missions. One of the key technologies for rovers is a suspension for traveling andperforming exploration missions; the suspension is an essential area of technology for a stable movement of a rover. In thisstudy, an 8-wheel suspension is designed to enable efficient climbing of slopes on a passage to the destination. For the twofront wheels among the eight wheels, the moment at the pivot connecting two wheels is derived when the distance betweenthe wheels and the torque of wheels are same. A test experiment was performed to compare the magnitude of momentaccording to the change in tilt angle and the position of the pivot. Finally, a suspension design considering the position ofthe pivot was proposed to enhance the hill-climbing performance.

지능형 로봇의 발전 동향

엄위섭(Eom, We-Sub),김연규(Kim, Youn-Kyu),이주희(Lee, Joo-Hee),최기혁(Choi, Gi-Hyuk),심은섭(Sim, Eun-Sup) 한국항공우주연구원 2013 항공우주산업기술동향 Vol.11 No.1

본 논문은 지능형 로봇의 발전 동향에 관하여 기술한 것이다. 지능형 로봇 기술은 기계, 전기·전자, S/W, 제어, 통신, 재료 등 다양한 첨단 기술의 융합 분야이다. 점차 진화해가는 로봇에 대한 정의 및 분류를 통하여 지능형 로봇에 대한 특징, 주요 활용분야와 기술수준에 대해 소개하고, 현재 연구가 진행중인 지능형 로봇의 주요 핵심기술을 설명하였다. 또한, 최근 국내외의 연구동향에 대하여 기술하고 향후 발전방향에 대해 분석하였다. 분석된 결과를 바탕으로 향후 우리나라의 자동차, 가전, 스마트 홈, 조선, 항공·우주 등 산업전반에 걸쳐 활용이 가능한 지능형 로봇 연구 개발에 참고가 되기를 희망한다. In this paper, the development trend of intelligent robots is described. Intelligent robot technologies are converging fields of high technology like the mechanics, electricity and electronics, software, controls, communications, materials, etc.. It is explained the characteristics, major application fields, level of technologies and major core technologies of intelligent robots introducing the concept and classification of robots that are continued to evolve. In addition, recent research trends are described and future development directions are analysed. Based on results of the analysis about intelligent robot technologies that can used to industries such as car, consumer-electronics, smart home service, shipbuilding, aerospace, etc., We hope to be referred that our country will research and develop in the future.

Auto-Calibration을 이용한 Unstructured Environment에서의 실내 위치추정 기법

엄위섭(We-sub Eom),서대근(Dae-Geun Seo),박재현(Jae-Hyun Park),이장명(Jang-Myung Lee) 제어로봇시스템학회 2009 제어·로봇·시스템학회 논문지 Vol.15 No.2

This paper proposes a way of expanding the use area of localization technique by using a beacon. In other words, we have developed the auto-calibration algorithm that recognizes the location of this beacon by attaching the beacon on an arbitrary position and by using the information of existing beacon under this situation. By doing so, the moving robot can overcome the limitation that the localization of moving robot is only possible within the area that has installed the existing beacon since the beacon cannot be installed on the accurate location when passing through a danger zone or an unknown zone. Accordingly, the moving robot can slowly move to the unknown zone according to this auto-calibration algorithm and can recognize its own location at a later time in a safe zone. The localization technique is essentially needed in using a moving robot and it is necessary to guarantee certain degree of reliability. Generally, moving robots are designed in a way to work well under the situation that the surroundings is well arranged and the localization techniques of using camera, laser and beacon are well developed. However due to the characteristics of sensor, there may be the cases that the place is dark, interfering radio waves, and/or difficult to install a beacon. The effectiveness of the method proposed in this paper has been proved through an experiment in this paper.

NASA의 무인 행성탐사용 로버 발전 동향

엄위섭(Eom, We-sub),김연규(Kim, Youn-kyu),이주희(Lee, Joo-hee),최기혁(Choi, Gi-hyuk),심은섭(Sim, Eun-sup) 한국항공우주연구원 2012 항공우주산업기술동향 Vol.10 No.2

본 논문은 미국의 NASA에서 개발되어 화성 탐사 임무를 수행하였거나 현재 수행중인 무인 행성탐사용 로버의 발전동향에 관한 것이다. Mars Pathfinder, MER, MSL 프로그램 각각에 대한 탐사 임무의 목표 및 목적, 로버의 특징, 주행 장치, 탑재된 과학 장비의 기능, 임무 기간 동안 이동한 경로와 임무 종료 등에 관해 개략적으로 정리하였다. 또한, 부여된 임무의 다양성과 발사체, 과학 장비, 시스템 제어, 우주 기술 등의 발전에 힘입어좀 더 구체적이고 정밀한 탐사 자료의 획득을 위해 점차 대형화 되어 가는 로버의 특징들을 분석하였다. 분석된 결과를 바탕으로 향후 우리나라의 로버 연구 개발에 참고가 되기를 희망한다. In this paper, the development trend of NASA"s unmanned planetary exploration rover that had performed or has performed the Mars exploration is summarized. For each program such as Mars Pathfinder, MER and MSL mission, goals and objectives of the exploration mission, characteristics of rovers, mobility system of rovers, roles and functions about equipped science instruments, travel path of each rover during the period of mission and missions terminated are summarized. In addition, features of rovers that are larger for acquiring more specific and precise data about Mars exploration are determined according to the development of technologies such as granted mission diversity, projectiles, science instruments, system control and space technologies, etc. Based on results of the analysis, We hope to be refered about a rover that our country will research and develop in the future.

Hazardous Area Navigation with Temporary Beacons

이장명,엄위섭,박재현 제어·로봇·시스템학회 2010 International Journal of Control, Automation, and Vol.8 No.5

A new area expansion algorithm for the localization scheme, using temporary beacons, is proposed in this paper. The effective area of the active beacons is limited by the strength of the ultrasonic signals in a noisy environment. When a mobile robot needs to move into a hazardous area or into an unstructured environment where the beacons with pre-specified position information are not available, the localization may solely rely on dead reckoning sensors such as encoders. To overcome the error accumulation by using dead-reckoning, a new scheme is developed, in this paper, in which the mobile robot carries a few temporary beacons which do not have any pre-stored position information. When the mobile robot encounters a dangerous or unstructured environment, it utilizes the temporary beacons to localize itself. An auto-calibration algorithm has been developed to provide the position in-formation to the temporary beacons before they are used for the localization. With these temporary beacons and the auto-calibration algorithm, mobile robots can safely pass unstructured areas. The ef-fectiveness of the temporary beacons and auto-calibration algorithm is verified through real experi-ments of mobile robot navigation.

Design of Mobility System for Ground Model of Planetary Exploration Rover

김연규,엄위섭,이주희,심은섭 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.

피드백 선형화법을 이용한 우주비행체의 대기권 재진입에 관한 유도제어

이대우,조겸래,엄위섭 한국항공우주학회 1999 한국항공우주학회 학술발표회 논문집 Vol.- No.-

우주파편 충돌위험 종합관리시스템 개념설계

김해동,김은혁,엄위섭,김은규,김학정 한국항공우주학회 2011 한국항공우주학회 학술발표회 논문집 Vol.2011 No.11

지난 2007년 이후 중국 Fengyun 1C 요격실험 이후 발생한 주요 우주충돌 사건들은 우주환경을 급속히 악화시키고 있다. 추적이 가능한 지름 10cm 이상의 우주물체들의 개수만 보더라도 2006년까지 13,000개였던 것이 2009년 미-러 위성 충돌 이후에는 22,000여개로 증가한 것으로 추정된다. 이처럼 우주파편과의 충돌위험성이 크게 증가함에 따라 기존의 미국, 유럽연합 (ESA) 뿐만 아니라, 프랑스, 독일, 일본, 중국 등에서도 자국 위성들의 우주파편 충돌위험을 경감시키기 위한 분석 소프트웨어를 개발하거나 사용 중에 있다. 본 논문에서는 운용하는 인공위성과 우주파편 상호간의 충돌위험을 분석하고, 위협을 주는 우주물체에 대한 정밀 궤도결정 및 예측을 통해 최적화된 충돌회피기동 계획을 생성할 수 있는 '우주파편 충돌위험 종합관리시스템'의 개념설계 내용을 소개하였다. 내용에는 개발하고자 하는 시스템의 특징, 주요 요구사항, 인터페이스, 운용개념들을 기술하였다. 추후 개발된 시스템은 우리나라가 운용하는 위성들의 우주파편 충돌위험을 경감시키기 위한 중요한 도구로 활용될 수 있을 것으로 기대한다. Space environment is dramatically deteriorating since Chinese anti-satellite test(ASAT) with Fengyun 1C in 2007 and major space collision events over last 3 years have happened. The number of space debris with a diameter of 10 cm that can be tracked is increasing up to 22,000 since space collision between US and Russia occurred, while that of space debris remained around 13,000 by the end of 2006. Due to the growth of space collision risk, analysis tools to mitigate the risk of space conjunction for their own satellites have been developed and operated by the France, Gemany, Japan, and China, as well as US and ESA. In this paper, the conceptual design of the space debris collision risk management software is presented. The characteristics, major requirements, interfaces, operational concept for the system are presented. In the near future, the developed system shall be expected as an important tool to mitigate the space debris collision risk for the Korean's satellites.