동적 환경을 위한 A^* 알고리즘 기반의 경로 및 속도 프로파일 설계

권민혁,강연식,김창환,박귀태,Kwon, Min-Hyeok,Kang, Yeon-Sik,Kim, Chang-Hwan,Park, Gwi-Tae 제어로봇시스템학회 2011 제어·로봇·시스템학회 논문지 Vol.17 No.5

This paper presents a hierarchical trajectory planning method which can handle a collision-free of the planned path in complex and dynamic environments. A PV (Path & Velocity profile) planning method minimizes a sharp change of orientation and waiting time to avoid a collision with moving obstacle through detour path. The path generation problem is solved by three steps. In the first step, a smooth global path is generated using $A^*$ algorithm. The second step sets up the velocity profile for the optimization problem considering the maximum velocity and acceleration. In the third step, the velocity profile for obtaining the shortest path is optimized using the fuzzy and genetic algorithm. To show the validity and effectiveness of the proposed method, realistic simulations are performed.

차체 레이아웃 설계를 위한 위상최적설계의 적용

이홍우(Hong Woo Lee),강연식(Yeon Sik Kang),김재현(Jaehyun Kim) 한국자동차공학회 2011 한국자동차공학회 학술대회 및 전시회 Vol.2011 No.11

This paper presents topology optimization as a tool for structural lay-out design of auto body, especially underbody. BESO(bi-directional evolutionary structural optimization) based on finite element method is applied to create optimal lightweight underbody under various external load conditions. In order to treat multi-load condition, weighted average objection function was introduced. According to the numerical formulae, a PC-based test program is coded in Fortran. To verify the proposed test program, the numerical results on several benchmark problems are compared with those obtained by references. The validity of the topology optimization is examined through the numerical examples on EV(electric vehicle) underbody concept design.

SUAV 착륙장치 오리피스의 파라미터 연구

한재도(Jae-Do Han),강연식(Yeon-Sik Kang),안오성(Oh-Sung Ahn),이영신(Young-Sin Lee) 한국항공우주학회 2009 韓國航空宇宙學會誌 Vol.37 No.1

본 연구에서는 스마트 무인기와 같은 소형 항공기 착륙 장치 낙하특성을 해석하고, 충격흡수효율 최적화를 위한 오리피스의 최적설계를 수행하였다. 스마트 무인기의 착륙장치의 방식은 미터링 핀이 없는 단순 유공압(oleo-pneumatic) 방식을 사용한다. 이 착륙장치를 상용 프로그램인 MSC ADAMS를 이용하여 모델링하였다. 해석 모델의 적합성을 확인하기 위해 해석된 결과와 시험 결과와 비교 검증 하였다. 해석 결과와 시험 결과는 잘 일치하였으며, 이를 통해 해석 모델이 본 낙하해석에 적합하게 모델링 되었음을 확인하였다. 검증된 해석 모델을 적용한 후, 오리피스의 크기를 변경하여 해석함으로써 가장 높은 효율을 가지는 최적의 오리피스 크기를 결정하였다. In this paper, the drop characteristic of the small aircraft landing gear of SUAV has been analyzed and performed on orifice optimal design for shock absorption efficiency. The SUAV landing gear was simple oleo pneumatic type without metering pin. The landing gear was modelled by MSC ADAMS software. Drop test evaluation was conducted to confirm the analysis model. As a result of correlation between analysis and test results, it was verified that these results were coincided with very well. After confidence review of analysis model through the correlation between test and analysis results, design parametric study was performed by using confirmed analysis model. Optimal orifice size with best efficiency have been decided in this study.

레이더와 비전 센서를 이용하여 선행차량의 횡방향 운동상태를 보정하기 위한 IMM-PDAF 기반 센서융합 기법 연구

장성우(Sung-woo Jang),강연식(Yeon-sik Kang) 제어로봇시스템학회 2016 제어·로봇·시스템학회 논문지 Vol.22 No.8

It is important for advanced active safety systems and autonomous driving cars to get the accurate estimates of the nearby vehicles in order to increase their safety and performance. This paper proposes a sensor fusion method for radar and vision sensors to accurately estimate the state of the preceding vehicles. In particular, we performed a study on compensating for the lateral state error on automotive radar sensors by using a vision sensor. The proposed method is based on the Interactive Multiple Model(IMM) algorithm, which stochastically integrates the multiple Kalman Filters with the multiple models depending on lateral-compensation mode and radar-single sensor mode. In addition, a Probabilistic Data Association Filter(PDAF) is utilized as a data association method to improve the reliability of the estimates under a cluttered radar environment. A two-step correction method is used in the Kalman filter, which efficiently associates both the radar and vision measurements into single state estimates. Finally, the proposed method is validated through off-line simulations using measurements obtained from a field test in an actual road environment.

공동현상을 고려한 유공압 방식 착륙장치의 낙하특성에 관한 연구

한재도(Jae-Do Han),이영신(Young-Sin Lee),강연식(Yeon-Sik Kang),안오성(Oh-Sung Ahn),공정표(Jeong-Pya Kong) 한국항공우주학회 2009 韓國航空宇宙學會誌 Vol.37 No.2

본 논문에서는 소형항공기용 유-공압 방식(oleo pneumatic type) 착륙장치의 낙하특성을 연구하였다. 본 연구대상의 착륙장치의 방식은 미터링 핀이 없는 단순 유-공압 방식댐퍼 이다. 일반적으로 유-공압 방식의 착륙장치는 단순한 구조로 되어 있어 무게가 가볍고 좋은 충격흡수 효율을 가진다. 낙하해석을 위하여 상용 코드인 MSC ADAMS를 이웅하여 모델링 하였다. 모델링한 후에 해석과 시험결과의 상사성을 검증하기 위하여 일련의 시험이 수햄되었다. 시험과 해석결과의 보다 좋은 일치성을 얻기 위하여 해석 모델에 공동현상 효과가 고려되었다. 공동현상을 고려한 착륙장치의 동적 거동 시뮬레이션 결과들이 현저하게 개선되었으며 시험결과와 보다 잘 일치함을 확인하였다. 이러한 과정을 통해 신뢰성이 검증된 해석모델을 이용하여 경사면에 대해서 해석적 방법을 통해 낙하특성을 예측하였다. This paper investigated the drop characteristics of oleo pneumatic type landing gear for small aircraft and the effects of cavitations in modeling the landing gear system. The landing gear system employed a simple oleo pneumatic type damper without a metering pin. In general, oleo-pneumatic type landing gears are light-weighted because of it's simplicity, yet they offer excellent impact absorption characteristics. In this study, the landing gear system was modeled using MSC ADAMS, which offers a drop simulation module. After modeling the system, a series of testing was conducted, using a prototype landing gear system, to validate the analysis model and simulation results. The effect of cavitation was considered in the simulation model to obtain a better correlation between the test and simulation results. The results show that adding the cavitation effect in the simulation model significantly improved the simulation model and better captured the dynamic behaviors of the landing system. Using the 'cavitation' model, dynamics characteristics of the landing gear were further evaluated for other landing conditions, such as landing in various angles of slopes.

스마트 무인 항공기 착륙장치 낙하충격 해석

공정표(Jeong-Pyo Kong),이영신(Young-Shin Lee),한재도(Jae-Do Han),강연식(Yeon-Sik Kang),안오성(Oh-Sung Ahn) (사)한국CDE학회 2008 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2008 No.1

풍력발전기 진단 및 청소를 위한 로봇의 모델링 및 자세제어

공진영(Jin-Young Kong),이재순(Jae-Soon Lee),강연식(Yeon-Sik Kang),조백규(Baek-Kyu Cho) 제어로봇시스템학회 2014 제어·로봇·시스템학회 논문지 Vol.20 No.9

Wind turbines are in the limelight in the alternative energy industry. However, they face frequent and various problems during operation. We focused on the supervising of the blades of a wind turbine. In this paper, we present the design of a maintenance robot that takes the size of wind turbine blades into consideration, so the general form of the robot is a square with four wires fixed to its vertices and to the nacelle. After the robot is placed near the nacelle, it moves along the blades. We also designed an attitude control algorithm for the robot to maintain its balance. Our control algorithm for the robot consists of roll and pitch attitude controllers and a height controller. Each controller was designed independently and then superposed together. We used simulations to verify our control algorithm.

통합형 튜브 하이드로포밍 금형 설계

차명환(Myung-Hwan.Cha),정기석(Gi-Suk.Chung),강연식(Yeon-Sik. Kang) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11

Tube hydroforming is a manufacturing process which has been widely used in automotive industry because of its good dimensional stability, low cost, and low weight. However, a relatively high cost of manufacturing the die of tube hydroforming has been one of the obstacles to extend the application of tube hydroforming. This paper presents a new concept of die design - integrated tube hydroforming die. The main concept of integrated die is the re-utilization of major parts of die, such as monoblock, base plate, and console. Size adjusting blocks were used to apply the integrated die to various parts with different shapes. Flexible design concept for console was developed to adjust position and angle of axial punch. As a result of applying integrated die to car exhaust parts, manufacturing cost of die was decreased by approximately 70%.

영광군 홍농읍 주변 해역의 동물플랑크톤 분포

金世華,姜演植,嚴熙文,林東賢 龍仁大學校 1995 용인대학교 논문집 Vol.11 No.-

Studies on the seasonal distribution of zooplankton were carried out in 1994 in waters off Yongkwang Atomic Power Plant. Zooplankton samples were collected four times seasonally at six selected stations. Forty - three taxa of zooplankton were distributed and 25 species representing 21 copepods, 2 chaetognaths, 1 protozoan and appendicularian were identified to species level. Zooplankton abundance varied between 840-42, 014 indiv. m-3 and were recorded the highest abundance in September and the lowest in February. Seasonal succession in the dominant species was observed from winter and spring with Acartia omorii to summer and autumn with A. pacifica and Paracalanus indicus. With the prevalence of ueritic copepods all the year round, i.e., A. omorii, A. pacifica and P. indicus, the studied waters were revealed to have the typical zooplankton fauna in coastal waters of the Yellow Sea.

혼 해석을 통한 초음파 폴리싱 시스템의 개발 및 연마특성

박병규,김성청,문홍현,이찬호,강연식 한국공작기계학회 2004 한국생산제조학회지 Vol.13 No.3

We have developed and manufactured an experimental ultrasonic polishing machine with frequency of 20kHz at the power of vibration 1.7kw for effective ultrasonic polishing in processing of high hardness material. Design of the horn is performed by the FEM analysis. The following, conclusions were empirically deduced through experimental results to the major elements which affect the surface roughness during the ultrasonic process by following the experimental plans. The ultrasonic polishing machine has been developed in parts of structure part, ultrasonic generator, vibrator. We were able to process the high hardness material without difficulty as a result of ultrasonic polishing by utilizing the groove added step-type horn. Through analyzing by applying the experimental plans, the rotating speed of the horn was determined to be the major factor in influencing the surface roughness. In the case of ceramic, wafer, we were able to obtain good surface roughness when the feed rate and the ultrasonic output were higher. Because the load on slurry particle increases when the ultrasonic output is higher, the processed becomes worse in the case of optical glass.