A Minimal Error Sub-Space Recognition Method using 3D Reconstruction from Multi Image Frames

Dongjin Han(한동진),We Sub Eom(엄위섭),Hern-soo Hahn(한헌수) 대한전자공학회 2010 대한전자공학회 학술대회 Vol.2010 No.6

We propose a new recognition method which minimizes the affect of the 3D error of stereo reconstruction or video reconstruction. After 3D structure of an object is found via any Structure from Motion (SfM) method, 2D recognizers will be implemented on the minimal error sub-space of the object"s 3D reconstruction. For each image frame from either stereo images or video clips, the best 2D sub-space recognizer is determined by projecting objects original 3D (CAD) models onto each individual image frame"s 2D sub-space. Compared to the previous work [1] where 3D reconstruction was directly used for recognition, sub-space method will use sub-space to minimized the influence of the unknown 3D triangulation error.

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

We-Sub Eom,Joo-Hee Lee,Hyun-Cheol Gong,Gi-Hyuk Choi 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 destination in order to accomplish scientific missions. One of the key technologies for rovers is a suspension for traveling and performing exploration missions; the suspension is an essential area of technology for a stable movement of a rover. In this study, an 8-wheel suspension is designed to enable efficient climbing of slopes on a passage to the destination. For the two front wheels among the eight wheels, the moment at the pivot connecting two wheels is derived when the distance between the wheels and the torque of wheels are same. A test experiment was performed to compare the magnitude of moment according to the change in tilt angle and the position of the pivot. Finally, a suspension design considering the position of the pivot was proposed to enhance the hill-climbing performance.

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

Eom, We-Sub,Kim, Youn-Kyu,Lee, Joo-Hee,Choi, Gi-Hyuk,Sim, Eun-Sup 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.

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

Eom, We-Sub,Lee, Joo-Hee,Gong, Hyun-Cheol,Choi, Gi-Hyuk The Korean Space Science Society 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 destination in order to accomplish scientific missions. One of the key technologies for rovers is a suspension for traveling and performing exploration missions; the suspension is an essential area of technology for a stable movement of a rover. In this study, an 8-wheel suspension is designed to enable efficient climbing of slopes on a passage to the destination. For the two front wheels among the eight wheels, the moment at the pivot connecting two wheels is derived when the distance between the wheels and the torque of wheels are same. A test experiment was performed to compare the magnitude of moment according to the change in tilt angle and the position of the pivot. Finally, a suspension design considering the position of the pivot was proposed to enhance the hill-climbing performance.

Hazardous Area Navigation with Temporary Beacons

Eom, We-Sub,Park, Jae-Hyun,Lee, Jang-Myung 제어로봇시스템학회 2010 Transaction on control, automation and systems eng Vol. No.

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 information 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 effectiveness of the temporary beacons and auto-calibration algorithm is verified through real experiments of mobile robot navigation.

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.

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.

설계방법에 따른 π형 RC 라멘교의 배근상셰

위증복(We, Jeung Bok),이승훈(Lee, Seung Hun),엄장섭(Eom, Jang Sub),진치섭(Jin, Chi Sub) 한국콘크리트학회 2006 한국콘크리트학회 학술대회 논문집 Vol.2006 No.11

RLS를 이용한 ETB의 PID Gain Auto Tuning

전찬성(Chan-Sung Jeon),엄위섭(We-Sub Eom),최승욱(Sung-Yug Choi),이장명(Jang-Myung Lee) 대한전자공학회 2007 대한전자공학회 학술대회 Vol.2007 No.7

This paper presents a PID automatic gain-tuning algorithm for the ETB (electronic throttle body) which is driven by wire. Since the system characteristics of position control for electronic throttle valve are so complicated that both the real time robustness and the manufacturing cost must be considered for mass production. To resolve this paradox, a kind of algorithm called RLS (Recursive Least Square) is adopted for the control of the ETB. Using this algorithm, the PID gains can be adjusted automatically with the estimated system parameters.