• 한국해양환경ㆍ에너지학회지
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• 제16권4호
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• pp.255-262
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• 2013

본 연구에서는 연속체 이론을 배경으로 하며 일반적으로 많이 사용되는 Navire-Stokes방정식이 아닌 입자의 확률분포를 배경으로 하는 Boltzmann 방정식을 이용하여 자유수면을 포함하는 유동을 해석하는 전산시뮬레이션 코드를 개발하였다. 댐 붕괴시뮬레이션에 적용하여 코드의 검증을 수행하였으며, 기존의 실험 및 계산결과와 비교함과 동시에 격자볼츠만 시뮬레이션의 특성을 분석하였다. 공학적 응용을 위해서 임의 형상의 물체가 존재시에 자유수면 시뮬레이션도 수행하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.626-630
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• 2005

This paper presents a novel Intelligent-Welding-Carriage (IWC) for automation of curved block in shipbuilding. The curved block is usually used in both front and back side of the ship. In curved block root gap is big, $1{\sim}7$ [mm] and inclination, $0{\sim}30$ [deg]. Since available conventional carriage type is limited to use below root gap of 3 [mm], only manual welding is employed in curved block. To adopt an IWC in curved block, it requires control of the welding conditions, i.e., voltage, current and travel speed, with respect to root gap and inclination to achieve good welding quality. In this paper, an IWC is developed for automization of welding operation to accommodate gap and inclination. Kinematics model and dynamics using Lagrangian formulation of the manipulator is introduced. IWC utilizes a database to perform accurate welding. The database is programmed based on numerous experimental test results with respect to gap, inclination, material, travel speed, weaving condition, voltage, and current. Finally, experimental result using PID control is addressed for verify the trajectory tracking accuracy of end-effector.

• 전자공학회논문지SC
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• 제49권3호
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• pp.12-18
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• 2012

본 논문에서는 항공기에 장착된 안테나가 정지 위성을 향하도록 관성측정기를 사용하여 지향각을 계산하는 방식을 제시한다. 대상 시스템에서 안테나는 항공기 앞에 위치하고 있고 몸체 유연성을 고려하기 위해 관성측정기를 도입하며, 항공기 중심부 GPS/INS와 안테나부 관성항법장치(INS) 사이의 위치와 속도 차이를 활용하여 스트랩다운 INS 표류 오차를 억제하기 위한 칼만필터를 설계한다.

• 한국생산제조학회지
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• 제23권4호
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• pp.374-379
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• 2014

Mobile robots with omni-directional wheels can generate instant omni-directional motion without requiring extra space to change the direction of the body. Therefore, they are capable of moving in an arbitrary direction under any orientation even in narrow aisles or tight areas. In this research, an omni-directional mobile robot based on Mecanum wheels was developed to achieve omni-directionality. A CompactRIO embedded real-time controller and C series motion and I/O modules were employed in the control system design. Ultrasonic sensors installed on the front and lateral sides were utilized to measure the distance between the mobile robot and the side wall of a workspace. Through intensive experiments, a performance evaluation of the mobile robot was conducted to confirm its feasibility for industrial purposes. Mobility, omni-directionality, climbing capacity, and tracking performance of a squared trajectory were selected as performance indices to assess the omni-directional mobile robot.

• 전자공학회논문지
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• 제52권3호
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• pp.147-153
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• 2015

본 논문에서는 주차장 환경에서의 차량 사고 감지방법을 제안한다. 제안하는 방법은 차량 검출, 차량 추적, 사고 감지의 3단계로 구성된다. 차량 검출 단계에서는 픽셀 기반의 전경 검출 방법과 모션맵을 이용하여 차량을 검출하고, 차량 추적 단계에서는 검출된 차량 정보를 바탕으로 차량의 이동을 추적한다. 마지막 단계인 차량 사고 감지 단계에서는 차량의 이동 방향에 맞추어 사고 감지 영역을 지정하고 사고 감지 영역에서 발생하는 움직임의 변화량을 분석하여 차량 사고를 감지한다. 실험을 통해 제안하는 방법은 주차장 환경에서 발생하는 차량 사고를 효과적으로 검출함을 보였다.

• 대한교통학회지
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• 제14권4호
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• pp.107-129
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• 1996

Recently, surveillance system designed to collect various trsffic information are becoming new areas of development . Among these, the image detector is a ayatem which can measure the travel time and speed in realtime and this is emerging as the most effcient tool to be available in future related areas. But in measuring wide-area information in realtime, the image detector are yet full of problem in its accuracy. The aim of this ahesis is to develop an algorithms which can collect wide-area information such as travel time and travel speed in urban networks and freeways in realtime. The information on wide-area such as travel time and travel speed is important in accomplishing strategic function in traffic control. The algorithm developed from this study is based on the image tracking model which tracks a moving vehicle form image datas collected continuously, and is constructed to perform realtime measurement. To evaluate the performance of the developed algorithms, 600 ind vidual vehicles in total were used as data for the study, and this evaluation was carried out with the differenciation of day and night condition at the access roads in front of AJou University, In the statistical analysis results, the error rate was recorded as 5.69% and it has proved to be applicable on the field in both day and noght conditions.

• 대한조선학회 특별논문집
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• 대한조선학회 2005년도 특별논문집
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• pp.171-176
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• 2005

This paper presents a novel Intelligent-Welding-Carriage (IWC) for automation of curved block in shipbuilding. The curved block is usually used in both front and back side of the ship. In curved block root gap is big, 1-7 (mm) and inclination, 0-30 (deg). Since available conventional carriage type is limited to use below root gap of 3 (mm), only manual welding is employed in curved block. To adopt an IWC in curved block, it requires control of the welding conditions, i.e., voltage. current, weaving speed, dwell time and travel speed, with respect to root gap and inclination to achieve good welding qualify. In this paper, an IWC is developed for automization of welding operation to accommodate gap and inclination. Kinematics model and dynamics using Lagrangian formulation of the manipulator is introduced. IWC utilizes a database to perform accurate welding. The database is programmed based on numerous experimental test results with respect to gap, inclination, material, travel speed, weaving condition, voltage, and current. Finally, experimental result using PID control is addressed for verifying the trajectory tracking accuracy of end-effector.

• International Journal of Naval Architecture and Ocean Engineering
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• 제3권4호
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• pp.263-273
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• 2011

The diffuse interface model of Saurel et al. (2008) is used for the computation of compressible cavitating flows around underwater missiles. Such systems use gas injection and natural cavitation to reduce drag effects. Consequently material interfaces appear separating liquid and gas. These interfaces may have a really complex dynamics such that only a few formulations are able to predict their evolution. Contrarily to front tracking or interface reconstruction method the interfaces are computed as diffused numerical zones, that are captured in a routinely manner, as is done usually with gas dynamics solvers for shocks and contact discontinuity. With the present approach, a single set of partial differential equations is solved everywhere, with a single numerical scheme. This leads to very efficient solvers. The algorithm derived in Saurel et al. (2009) is used to compute cavitation pockets around solid bodies. It is first validated against experiments done in cavitation tunnel at CNU. Then it is used to compute flows around high speed underwater systems (Shkval-like missile). Performance data are then computed showing method ability to predict forces acting on the system.

• 유공압시스템학회논문집
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• 제5권4호
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• pp.1-9
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• 2008

In this paper, an energy regeneration algorithm is proposed to make the maximum use of the regenerative braking energy for a parallel hybrid electric vehicle(HEV) equipped with a continuous variable transmission(CVT). The regenerative algorithm is developed by considering the battery state of charge(SOC), vehicle velocity and motor capacity. The hydraulic module consists of a reducing valve and a power unit to supply the front wheel brake pressure according to the control algorithm. In order to evaluate the performance of the regenerative braking algorithm and the hydraulic module, a hardware-in-the-loop simulation (HILS) is performed. In the HILS system, the brake system consists of four wheel brakes and the hydraulic module. Dynamic characteristics of the HEV are simulated using an HEV simulator. In the HEV simulator, each element of the HEV powertrain such as internal combustion engine, motor, battery and CVT is modelled using MATLAB/$Simulink^{(R)}$. In the HILS, a driver operates the brake pedal with his or her foot while the vehicle speed is displayed on the monitor in real time. It is found from the HILS that the regenerative braking algorithm and the hydraulic module suggested in this paper provide a satisfactory braking performance in tracking the driving schedule and maintaining the battery state of charge.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 춘계학술대회
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• pp.815-818
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• 2016

전방 추돌 경보 시스템(FCWS) 및 차선 이탈 경보 시스템(LDWS)은 운전자 보조 시스템(ADAS)의 중요한 요소이다. 차량 전방 카메라를 이용한 차선 이탈 경보 시스템은 일반적으로 취득한 영상에서 직선 형태의 차선이나 RANSAC 등을 이용한 곡선을 추적하여 차량의 중심과 비교하게 된다. 이러한 알고리즘은 넒은 범위의 차선이 요구되고 곡선에 취약한 약점이 있다. 본 논문에서는 Top-view 공간에서 현재 차량을 기준으로 차선 이탈 여부를 검사하는 알고리즘을 제시한다. 이 알고리즘은 좁은 범위의 차선으로도 차량 이탈 여부를 검사할 수 있으며 잡음에 영향을 거의 받지 않는 결과를 보여준다.