교통사고분석을 위한 삼차원 재현장치 구현

권준용(Jun-Yong Kwon),김용득(Yong-Deuk Kim) 한국정보과학회 2001 한국정보과학회 학술발표논문집 Vol.28 No.1B

본 논문에서는 가속도 센서에 의해 사고를 검지하고 사고 전후의 영상정보를 저장하는 차량용 사고분석장치를 설계하였으며 이를 위한 사고 분석 시뮬레이터를 윈도우 기반에서 OpenGL 3차원 그래픽 라이브러리를 사용하여 구현하였다. 이는 알고리즘부와 디스플레이부로 구성되며, 알고리즘부에서는 도로 영상에 대한 영상처리를 수행한다. 여기서 개선된 역원근법에 의해 전처리된 영상을 필터링하여 차선을 검지하고, 검지된 차선을 이용하여 차선 파라미터들을 추출하며, 디스플레이부에서 추출된 파라미터들을 입력받아서 OpenGL 라이브러리 함수를 사용하여 사고를 3차원으로 재현한다.

압전유압펌프 성능실험에 대한 연구

주용휘(Yong-Hwi Joo),황재혁(Jai-Hyuk Hwang),양지연(Ji-Youn Yang),배재성(Jae-Sung Bae),이종훈(Jong-Hoon Lee),권준용(Jun-Yong Kwon) 한국항공우주학회 2015 韓國航空宇宙學會誌 Vol.43 No.9

본 논문에서는 압전재료를 이용하여 중소형 무인기 브레이크 시스템에 적용 가능한 압전유압펌프를 설계 및 제작하고, 제작된 압전유압펌프의 성능검증 실험을 수행하였다. 중소형 무인기급 목표 항공기를 선정하여 브레이크 시스템의 요구조건을 분석하였으며, 이를 바탕으로 압전유압펌프의 성능 요구조건을 선정하였다. 요구조건을 만족하는 압전유압펌프의 형상설계를 수행하였으며, 고속 동작 조건에서도 유체의 역류를 효과적으로 차단시킬 수 있는 체크밸브를 비롯한 모든 구성품을 제작하였다. 제작된 압전유압펌프의 성능검증을 위해 실험장치를 구성하여 무부하 토출특성, 부하 시 압력형성 특성실험을 수행하였다. 실험결과, 무부하 최대 토출유량은 80 Hz에서 120.04 cc/min이고, 부하 시 최대 토출압력은 140 Hz에서 783.17 psi이고, 압력형성 반응속도는 약 30 ms 이내임을 확인하였다. 이는 설계 제작된 압전유압펌프가 펌프성능 요구조건을 충족하고 있다고 판단된다. In this paper, the piezoelectric-hydraulic pump with a piezostack actuator as a driving source has been designed, fabricated, and evaluated for its application to UAVs brake system. The performance requirements of the piezoelectric-hydraulic pump were decided based on the requirements analysis of the target aircraft brake system. The geometric design of the piezoelectric-hydraulic pump to meet the performance requirements of the pump was conducted, and all components of the pump including the spring sheet type check valves were machined with close tolerance. By constructing a test apparatus for the performance check of the piezoelectric-hydraulic pump, the performance characteristics of the pump, such as the outlet flow rate for load-free condition and the outlet oil pressure for closed loop condition, have been evaluated. It has been found by the performance test result that the developed piezoelectric-hydraulic pump satisfies the design requirements effectively.

다중 센서 데이터를 이용한 무인기 유성감속기의 고장진단 연구

박형준(Hyung Jun Park),조성희(Seong Hee Cho),장경환(Kyung-Hwan Jang),설진운(Jin-Woon Seol),권병기(Byung-Gi Kwon),권준용(Jun-Yong Kwon),최주호(Joo-Ho Choi) 한국신뢰성학회 2020 신뢰성응용연구 Vol.20 No.4

Purpose: The harsh operating conditions of unmanned aerial vehicles cause crack propagation in the gear teeth in the actuator, which eventually leads to breakdown. For the prevention of service delays or failure because of crack propagation, a diagnostic process based on the built-in and add-on sensors’ signals is proposed for the planetary gearbox of unmanned aerial vehicles. Methods: A planetary gearbox test rig is constructed, and the motor current, the position and vibration signals are acquired for the normal and crack-induced states. Features representing the health state are extracted and selected by using a suitable performance measure. Subsequently, the K-Nearest Neighbor algorithm is applied to the selected features, from which the classifications of the normal and fault states are performed. Results: Among the acquired signals, the vibration signal obtained from add-on sensor showed better performance (100%, J₃ = 46.6) than the motor current (88.7%, J₃ = 3.89) and angular position (100%, J₃ = 5.88) acquired from the built-in sensor. In the features of the vibration signal, those in the frequency band with strong energy concentration showed outstanding separability. Conclusion: The proposed method successfully classifies the fault from the normal in the planetary gearbox in the basis of the frequency-domain features of the vibration signal.

자동 간극 조절기를 갖는 항공기용 유압식 브레이크 조립체 개발

이미선,송원종,권준용,Yi, Miseon,Song, Won-Jong,Kwon, Jun-Yong 한국군사과학기술학회 2020 한국군사과학기술학회지 Vol.23 No.5

This study was conducted to develop the hydraulic brake assembly for MUAV(Medium-altitude Unmanned Aerial Vehicle). The brake assembly has the self-gap adjuster which performs to maintain a constant gap between the piston and the disk, even if the friction pad wore down. The function of adjuster helps to keep the brake-reaction speed constant and prevent the unnecessary abrasion of the wear pad during the life of the brake assembly. The development of the aircraft hydraulic brake assembly with the self-gap-adjuster in this paper is the first ever in South Korea. The concept of the mechanism was defined and the formula which is necessary to calculate the friction force was set up in the paper. The tester was invented for the functional test and the proper operation of the self-gap-adjuster was confirmed through the test. Dynamo tests and flight tests were also carried out to verify the braking performance of the brake assembly.

인공신경망을 이용한 고장 심각도에 따른 무인기용 유성감속기의 고장진단 연구

박형준(Hyung Jun Park),심진우(Jinwoo Sim),장재원(Jaewon Jang),장경환(Kyung-Hwan Jang),설진운(Jin-Woon Seol),권준용(Jun-Yong Kwon),최주호(Joo-Ho Choi) 한국신뢰성학회 2021 신뢰성응용연구 Vol.21 No.4

Purpose: Gear teeth in the rotary geared actuator of the unmanned aerial vehicle, experience crack propagation because of its harsh operating conditions. To prevent the failure of catastrophic events, this study proposes a diagnostic approach for various gear crack levels based on the built-in and add-on sensor signal. Methods: A downsized planetary gearbox test rig was prepared, in which the motor position, current, and vibration signals were acquired for the normal and 4 different crack-induced states. Signals were filtered around the region of resonance frequencies by spectral kurtosis and the features for the health state were extracted. Then, feature selection was conducted based on the correlation with fault levels. Finally, the Artificial Neural Network (ANN) model was constructed to identify different fault sizes of the cracks, and K-fold validation was adopted to optimize the parameters of the ANN model. Results: Among the various signals, the vibration from the add-on sensor and a position from the built-in sensor exhibited high performance compared to the current signal. The features after band-pass filtering yielded a high correlation with fault severity. Conclusion: The proposed method successfully diagnosed different fault severities of gear cracks in the planetary gearbox by using both the built-in and add-on signals.

국산 커터헤드를 장착한 직경 3.6 m 토압식 쉴드TBM의 제작과 현장적용성 분석

배규진,장수호,최순욱,강태호,권준용,신민식,Bae, Gyu-Jin,Chang, Soo-Ho,Choi, Soon-Wook,Kang, Tae Ho,Kwon, Jun-Yong,Shin, Min-Sik 한국터널지하공간학회 2015 한국터널지하공간학회논문집 Vol.17 No.4

A domestic cutterhead with the diameter of 3.6 m was designed and manufactured in this study. Then, it was attached to an existing earth-pressure balanced shield TBM to excavate a cable tunnel with the length of 1,275 m. Especially, the procedures for TBM cutterhead design and its corresponding performance prediction were also summarized. From field data analyses of the refurbished shield TBM, its maximum advance rate was recorded as 14.4 m/day. Penetration depths of disc cutters were found to be approximately 4 mm/rev, which is equal to the maximum penetration depth designed for the strongest rock strength condition in the target tunnel. Every TBM operating thrust and cutter normal force during TBM driving was much smaller than their corresponding maximum capacities. When cutter acting forces recorded in the field were analyzed, their prediction errors by the CSM model were very high for weak rock conditions. In addition, rock strength showed very close relationships with cutter normal force and penetration depth. 본 연구에서는 직경 3.6 m의 국산 커터헤드를 설계 제작하고 이를 기존의 토압식 쉴드TBM에 적용하여 연장이 1,275 m인 전력구 터널의 굴착공사를 수행하였다. 특히, 본 연구에서는 TBM 커터헤드의 설계절차와 그에 따른 TBM 굴착성능을 예측하기 위한 방법들을 정리하였다. 제작된 국산 커터헤드 장착 토압식 쉴드TBM의 실제 굴진자료를 분석한 결과, 최대 굴진율은 14.4 m/day이었으며 암석의 일축압축강도가 가장 큰 조건에 대해 커터헤드의 설계단계에서 제시한 4 mm/rev 내외로 디스크커터의 관입깊이가 관리되었음을 확인하였다. 또한 TBM의 구동 추력과 디스크커터의 연직력은 각각 TBM의 최대 추력 용량과 디스크커터의 최대 허용 연직력이하로 나타났다. 현장에서 측정된 디스크커터의 작용력을 분석한 결과, 연암 조건에서 CSM모델의 예측 오차가 크게 나타남을 확인하였다. 마지막으로 암석의 일축압축강도와 디스크커터의 연직력 및 커터 관입깊이는 밀접한 상관관계를 나타내었다.

해저 배출관로 건설을 위한 토압식 쉴드TBM 커터헤드의 설계·제작 및 현장 굴진성능의 분석

배규진,장수호,박영택,최순욱,이규필,권준용,한경태,Bae, Gyu-Jin,Chang, Soo-Ho,Park, Young-Taek,Choi, Soon-Wook,Lee, Gyu-Phil,Kwon, Jun-Yong,Han, Kyoung-Tae 한국터널지하공간학회 2014 한국터널지하공간학회논문집 Vol.16 No.2

본 연구에서는 해저 배출관로 건설을 위한 직경 4.4 m 토압식 쉴드TBM을 설계 제작하였다. 압축강도가 가장 큰 구간을 대상으로 커터헤드를 설계하고 쉴드TBM의 핵심 사양을 검토하였다. 쉴드TBM의 최대 용량을 만족하기 위해서는 디스크커터의 관입깊이를 7 mm/rev 이하로 적용해야 하는 것으로 나타났다. 설계 제작된 재활용 쉴드TBM의 현장 굴진자료를 분석한 결과, 약 95%의 현장 관입깊이가 7 mm/rev이하였으며, 디스크커터와 TBM 최대 용량 이내로 굴진이 이루어졌음을 확인하였다. 또한 CSM모델에 의한 커터 작용력과 현장의 커터 작용력을 비교한 결과, CSM모델로 예측한 커터 적용력이 약 22~25% 크게 나타났으나 대체로 현장의 커터 작용력과 유사한 경향을 나타내었다. An earth pressure balanced shield TBM with the diameter of 4.4 m was designed and manufactured for a subsea discharge tunnel excavation. Its cutterhead was designed to be optimized for the strongest rock mass condition in the tunnel alignment, and then the applicability of the refurbished shield TBM was validated for its maximum capacity. Especially, the maximum cutter penetration depth for the strongest rock mass condition should be kept to be below 7 mm/rev in order to satisfy the allowable capacities of the shield TBM. From the analysis of TBM advance data, approximately 95% of field data showed the cutter penetration depth below 7 mm/rev. In addition, it was certified that the acting forces of every disc cutter, TBM thrust and torque during TBM driving were within the allowable capacities of the shield TBM and its disc cutters. When real acting forces of the disc cutters in the field were compared with those predicted by the CSM model, they showed the close relationships with each other even though the predictions by the CSM model were approximately 22~25% higher than field data.

지능재료펌프의 경량화기법 연구

정민지(Min-Ji Jeong),황재혁(Jai-Hyuk Hwang),배재성(Jae-Sung Bae),권준용(Jun-Yong Kwon) 항공우주시스템공학회 2016 항공우주시스템공학회 학술대회 발표집 Vol.2016 No.5

혼성동력계에서 주요 설계변수가 제동성능에 미치는 효과분석

이종훈(Jong-Hoon Lee),황재혁(Jai-Hyuk Hwang),정민지(Min-Ji Jeong),권준용(Jun-Yong Kwon) 한국항공우주학회 2016 韓國航空宇宙學會誌 Vol.44 No.11

브레이크 동력계는 브레이크의 성능을 시험하는 장치로 시험구역, 기계적 관성구역, 전기모터 및 제어구역으로 구성된다. 혼성동력계는 기계적 관성 구역의 크기를 줄이고 전기모터를 이용하여 브레이크 작동에 따른 기계적 관성의 손실을 보상하는 방식으로 상대적으로 작은 기계적 관성 크기와 적은 비용으로 시험이 가능한 장점이 있다. 본 논문에서는 공간적 제약이 있는 실험실에 적절한 혼성동력계를 설계하였고, 설계된 혼성동력계에서 마찰계수 변화 등 주요 설계변수가 혼성동력계 제동성능에 미치는 영향을 분석하였다. 본 연구를 통해 축소된 기계적 관성에 의한 에너지 손실을 보상하기 위한 전기 모터의 토크를 측정하면 마찰재의 불량여부를 판단 할 수 있는 결과를 얻었다. Dynamometer is a device for testing the performance of the brake and it is composed of a test zone, the mechanical inertia zone, the electric motor and the control zone. Hybrid dynamometer is a way to compensate for the loss of mechanical inertia in accordance with the brake operation by using an electric motor to reduce the size of the mechanical inertia with the advantage that can be tested in the relatively small size of the mechanical inertia and low cost. In this paper, design the proper size of hybrid dynamometer in the laboratory level with the space constraints, analysed the effect of critical parameter on the braking performance of hybrid dynamometer such as changing the friction coefficient. With this study, could get the results of guideline to judge the poor friction material by measuring the torque of the electric motor to compensate the energy loss due to a reduced mechanical inertia.

브레이크용 소형 압전유압펌프 가압 동특성 해석

정민지(Min-Ji Jeong),황재혁(Jai-Hyuk Hwang),배재성(Jae-Sung Bae),권준용(Jun-Yong Kwon) 한국항공우주학회 2015 韓國航空宇宙學會誌 Vol.43 No.11

본 연구에서는 압전유압펌프의 챔버부, 체크밸브, 부하, 펌프구동제어기 등 유압펌프 전체 구성품의 해석 모델링을 통하여 브레이크용 소형 압전유압펌프의 가압 동특성을 해석하였다. 가압 동특성을 해석하기 위해 먼저 적층형 압전작동기가 챔버내에서 압력을 형성하는 과정을 모델링하였다. 체크밸브 개도에 따른 유량계수 식을 얻기 위해, 유한요소코드 해석을 통해 체크밸브 압력분포 및 유동결과를 얻은 후 체크밸브 유량계수식을 커브 피팅으로 유도하였다. 또한 부하압력을 피드백 받아 작동기 입력전압을 제어하여 부하압력이 입력명령 압력을 잘 추종하도록 펌프구동제어기를 설계하였다. 시뮬레이션 결과 브레이크 작동에 필요한 정상작동압력까지 도달하는데 걸리는 시간은 약 0.03ms 정도이다. 본 연구에서 얻어진 해석 시뮬레이션 결과는 실제 실험결과와 비교를 통해 타당성을 검증하였다. In this study, the pressurization characteristics of the small piezoelectric hydraulic pump for a brake system has been analyzed through modeling the full hydraulic pump components; the pump chamber, check valve, pump load, pump drive controller etc. To analyze the pressurization characteristics, the process of charging pressure in the chamber with stacked-layer piezoelectric actuator were firstly modeled. Secondly, the flow coefficient of the check valve in terms of valve opening has been calculated after computational fluid dynamics analysis, such as the pressure distribution around check valve and the flow rate, was conducted. Also the pump driving controller, which controls the input voltage to the actuator, was designed to make the load pressure follow the input pressure command. The simulation results find that it takes about 0.03ms to reach the operating load pressure required for the braking system. The simulation result was also verified through comparison to the result of the pump performance test.