Modified $A^*$ - 방향별 속도지도를 활용한 무인차량의 지역경로계획

이영일,이호주,박용운,Lee, Young-Il,Lee, Ho-Joo,Park, Yong-Woon 한국군사과학기술학회 2011 한국군사과학기술학회지 Vol.14 No.3

It is necessary that UGV(Unmanned Ground Vehicle) should generate a real-time travesability index map by analyzing raw terrain information to travel autonomously tough terrain which has various slope and roughness values. In this paper, we propose a local path planning method, $MA^*$(Modified $A^*$) algorithm, using DVGM (Directional Velocity Grid Map) for unmanned ground vehicle. We also present a path optimization algorithm and a path smoothing algorithm which regenerate a pre-planned local path by $MA^*$ algorithm into the reasonable local path considering the mobility of UGV. Field test is conducted with UGV in order to verify the performance of local path planning method using DVGM. The local path planned by $MA^*$ is compared with the result of $A^*$ to verify the safety and optimality of proposed algorithm.

도심환경 자율주행을 위한 자율매니저 기반 경로계획 기법

이영일,안성용,김종희,Lee, Young-Il,Ahn, Seong-Yong,Kim, Chong-Hui 한국군사과학기술학회 2013 한국군사과학기술학회지 Vol.16 No.6

In this paper, we propose a local path planning method based on RANGER algorithm and autonomy manager for autonomous navigation of UGV in urban environment. LPP method is designed to generate the local path in sensing area by using lane and curb of pavement and autonomy manager is designed to make a decision which transit the status of LPP component to a proper status for current navigation environment. A field test is conducted with scenarios in real urban environment in which crossroad, crosswalk and pavement are included and the performance of proposed method is validated.

Areal Rainfall Analysis using Grid Method

이영일,Lee Yong-il Korean National Committee on Irrigation and Draina 1994 한국관개배수논문집 Vol.1 No.2

미국 펜실베이니아 주의 4개 지역에 대해 면적우량을 분석하였다. 강수량이 제일 큰 지점에서 시작하여 이 지점 주위로 직사각형의 블럭을 확장하여 만들었다. 이 직사각형 블럭의 강수량을 구한 후 최대 지점 강수량에 대한 비를 구하였다. 이 강수량 비(Relative storm magnitudes)를 플롯트하여 기존의 커브와 비교하였으며, 각 지역에 대해 여름과 겨울의 강수량비를 각각 구하였다. 또한 등우량선도를 이용한 분석도 시도해 보았다. 이 연구에서 구

퍼지관계곱을 이용한 수중운동체의 고수준 자율항행기법

이영일,김용기,Lee, Young-Il,Kim, Yong-Gi 한국정보과학회 2002 정보과학회논문지 : 소프트웨어 및 응용 Vol.29 No.1

This paper describes a heuristic search technique carrying out collision avoidance for Autonomous Underwater Vehicles(AUVs). Fuzzy relational products are used as the mathematical implement for the analysis and synthesis of relations between obstacles that are met in the navigation environment and available candidate nodes. In this paper, we propose a more effective evaluation function that reflects the heuristic information of domain experts on obstacle clearance, and an advanced heuristic search method performing collision avoidance for AUVs. The search technique adopts fuzzy relational products to conduct path-planning of intelligent navigation system. In order to verify the performance of proposed heuristic search, it is compared with $A^*$ search method through simulation in view of the CPU time, the optimization of path and the amount of memory usage. 본 논문에서는 자율수중운동체(AUVs, Autonomous Underwater Vehicles)의 실시간 충돌회피를 위한 휴리스틱 탐색기법을 논한다. 퍼지관계곱(fuzzy relational products)은 항행 환경에서 발생하는 장애물과 다음으로 이동 가능한 후보노드들과의 관계를 분석, 종합하는 수학적 도구로 사용된다. 본 논문은 영역전문가 보유한 장애물회피 관련 경험적 정보(heuristic information)를 반영하여 보다 효율적인 평가함수(evaluation function)를 고안하며 지능항행시스템의 상세경로설정(local path-planning)에 퍼지관계곱을 적용하여 보다 개선된 휴리스틱 탐색기법을 제안한다. 제안된 탐색기법의 성능검증을 위해 수행시간(cpu time), 경로의 최적화(optimization) 정도, 그리고 사용 메모리 관점에서 시뮬레이션을 통해 $A^{*}$ 탐색기법과 비교한다.

무인잠수정의 자율운항시스템을 위한 시뮬레이터 개발

이영일,민종수,송진국,김용기,Lee, Young-Il,Min, Jong-Soo,Song, Jin-Kook,Kim, Yong-Gi 한국정보통신학회 2008 한국정보통신학회논문지 Vol.12 No.3

시뮬레이터의 목적은 새로운 기술의 검증방법을 제공하거나 새로운 기술을 특정 응용분야에 적용시키기 위한 효율적인 방법을 제공하는 것이다. 무인잠수정의 개발 과정에 있어, 시뮬레이션은 고비용과 위험성을 내포하는 현장 시험의 효율적인 대안으로 제시될 수 있다. 본 논문에서는 RVC 지능시스템 모델에 기반을 두어 개발된, 무인잠수정을 위한 자율운항시스템의 성능검증을 위해 3D 시뮬레이터를 설계 및 구현한다. 제안하는 시뮬레이터는 환경관리자(Environment Manager), 객체(Object), 그리고 3차원 뷰어(3D Viewer)로 구성된다. 구성요소 중 객체는 운항환경을 구성하는 지형, 장애물, 무인잠수정과 같은 물리적인 요소를 모델링한 것이다. 이러한 객체들은 환경 관리자에서 표현하는 대상에 맞게 생성하고 초기화된다. 환경 관리자는 생성된 객체들이 상호 작용할 수 있도록 중개자 역할을 수행하고 3차원 뷰어에게 3차원 표현에 필요한 정보를 전달한다. 3차원 뷰어는 전달받은 정보를 바탕으로 OpenGL의 프리미티브를 조합하여 3차원적으로 시각화한다. The goal of a simulator is to provide for the testing of new technologies and to facilitate the eventual transfer of these technologies to the applications. In the Development Step, Simulation can provide a cost effective alternative to expensive and hazardous field testing. In this paper, a 3D simulator is developed to test UUV navigation system bated on RVC model. The simulation system consists of a environment manager, objects and a 3D viewer. Objects are modeling all physical elements such as map, obstacle and UUV which reside in a underwater environment. Those objects are created and initialized by environment manager. The environment manager plays the role of intermediator which allows created objects to interact with each other, and transmits information on the objects to 3D viewer. The 3D viewer analyzes the received information and visualizes 3D graphic by using OpenGL primitives.

야지환경의 비포장도로용 지역경로계획

이영일,최덕선,박용운,Lee, Young-Il,Choe, Tok Son,Park, Yong Woon 한국군사과학기술학회 2013 한국군사과학기술학회지 Vol.16 No.6

It is required for UGV(Unmanned Ground Vehicle) to have a LPP(Local Path Plan) component which generate a local path via the center of road by analyzing binary map to travel autonomously unpaved road in rough environment. In this paper, we present the method of boundary estimation for unpaved road and a local path planning method based on RANGER algorithm using the estimated boundary. In specially, the paper presents an approach to estimate road boundary and the selection method of candidate path to minimize the problem of zigzag driving based on Bayesian probability reasoning. Field test is conducted with scenarios in rough environment in which bush, tree and unpaved road are included and the performance of proposed method is validated.

무인차량의 자율주행을 위한 지역경로계획 매니저

이영일,이호주,박용운,Lee, Young-Il,Lee, Ho-Joo,Park, Yong-Woon 한국군사과학기술학회 2010 한국군사과학기술학회지 Vol.13 No.6

The Mission environment of UGV(Unmanned Ground Vehicle) has a complexity and variety, and the status of system and sensor is dependent on the environment factors such as operation time, the weather and road type. It is necessary for UGV to cope adaptively with the various mission types, operation modes and operation environment as human operators do. To satisfy this necessity, we present an autonomy manager based on the autonomous architecture. In this paper, we design a path planning software architecture and LPP manager by using open autonomous architecture which is previously designed by ADD. Field test is conducted with UGV in order to verify the performance of LPP Manager based on the Autonomous Architecture with scenarios.

황련뿌리 추출물성분이 흰쥐의 지질대사에 미치는 효과

이영일,이상영,최용순,Lee, Young-Il,Lee, Sang-Young,Choi, Yong-Soon 한국생약학회 1996 생약학회지 Vol.27 No.3

Coptis rhizoma was extracted with methanol or hot water. Methanol extracts had higher berberine content than water extracts, whereas the contents of Ca, Mg, Zn and K were higher in the water extracts. Rats were fed on the purified diets rich in 0.12% cholesterol only or supplemented with 0.5% of each extracts for four weeks. The concentration of total serum cholesterol was significantly lower in the rats given the extracts, irrespective of the extractants. Although the concentration of serum HDL-cholesterol was comparable among the groups, the ratio of HDL-/total-cholesterol was higher in rats given the extracts. The concentration of serum free fatty acids and ketone body were significantly elevated in rats given the extracts. On the other hand, the extracts supplements significantly decreased the contents of liver cholesterol and triacylglycerol. The amount of fecal bile acids was markedly higher in rats given the extracts, especially in those given water extracts. The results show an effective hypocholesterolemic action of Coptis rhizoma and it seems that the lower concentration of serum and liver cholesterol is resulted from the increased fecal bile acids in rats.

계통연계형 소형풍력발전기 제어

이영일(Young Il Lee),안경필(Kyung Pil Ahn),이준성(Jun Sung Lee),손성용(Sung-Yong Son),김창섭(Chang Seob Kim) 대한전기학회 2009 정보 및 제어 심포지엄 논문집 Vol.2009 No.10

계통연계 기능을 갖춘 3㎾급 수직축 풍력발전기의 제어시스템 구성에 관한 내용을 다룬다. 영구자석형 동기발전기 측과 계통 측에 각각 인버터를 설치하여 각각 최대전력 추종제어와 전력품질제어를 수행한다. 영구자석형 풍기발전기의 전류셰어를 통해서 발전기의 EM(Electro Magnetic) 토크를 조절하고 이를 통해서 최대효율을 얻을 수 있는 회전속도가 나오도록 한다. 계통측 인버터는 상태벡터 제어를 통해서 전압과 역율제어를 수행한다. 본 논문에서는 이와 같은 기본적인 아이디어를 소개하고 Matlab을 이용한 시뮬레이션을 수행한다.

제주도 밭작물 용수량 산정방법

이영일 ( Lee Yong-il ),김현수 ( Kim Hyeon-soo ),임한철 ( Lim Han-cheo ),문경환 ( Song Chang-khil ),송창길 ( Moon Kyung- Hwan ),강봉균 ( Kang Bong-kyoon ) 한국농공학회 2005 한국농공학회 학술대회초록집 Vol.2005 No.-

Crop evapotranspiration rates of the garlic, potato and carrot were measured in a lysimeter at the National Institute of Subtropical Agriculture. The crop coefficients were calculated using the values of the actually measured evapotranspiration(ETcrop) and the reference crop evapotranspiration (ETo) estimated by the Penman-Monteith equation. The maximum crop coefficients of the garlic, potato, carrot and cabbage were 1.07, 1.07, 0.73 and 0.92 respectively. For the Citrus Aoshima Unshiu and Hallabong in the plastic house, the maximum crop coefficients were 1.38 and 1.29 respectively. Computer program using EXCEL was also developed to estimate the crop water use.