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신동준,이종학,강영식,Shin, Dongjun,Lee, Jonghak,Kang, Youngsik 한국군사과학기술학회 2017 한국군사과학기술학회지 Vol.20 No.1
In this paper, design requirements of the large radar were investigated, and development was performed through the analysis and design. Large radar should be designed by bearing the 75 knot wind force and $20kg/m^2$ ice mass as operating conditions in order to meet structural stability, and driving torque and bearing load were calculated for securing the driving stability. Thermal dissipation analysis was performed considering TRM and DC-DC Converter's limitation temperature by $50^{\circ}C$ ambient temperature condition in order to attain thermal stability, and PSD and shock analysis were carried out by using MIL-STD-810G vibration and shock specification in order to transport and installation of the large radar. As a result, all components of large radar could secure the structural stability more than 2.8 factor of safety, and driving stability was also secured with adequate bearing fatigue life. Thermal stability was attained by allowable max temperature 88.7 C of the TRM, and structural stability for transportation and installation of the large radar was also secured more than 5 factor of safety. After it was transported and installed to the radar site, operating capability was finally verified by rotating the large radar.
통합마스트-송수신 모듈의 열화인자 분석을 통한 결함진단 및 잔여수명 예측 연구
고호진(Hojin Koh),이종학(JongHak Lee),라영은(YoungEun Ra),강민성(Minsung Kang),유영민(Yeongmin Yoo),권대일(Daeil Kwon),이종수(Jongsoo Lee) (사)한국CDE학회 2020 한국CDE학회 논문집 Vol.25 No.2
Frequently installed on latest destroyers, integrated mast (I-mast) conducts tasks including coast and air-space surveillances. I-mast is a complex multi-domain system with various mechanical and electrical subsystems and components. In the perspective of diagnosis and maintenance, it is important to technologically manage this system for long operating time periods and eventually increase its survivability. We explore the prognostics and health management (PHM) process of I-mast and transmitter receiver module (TRM) using the framework of Modelica-based system simulation. With Modelica, one can reuse components employed in a model, easily model a system expressed in mathematical language, and conduct a multi-dimensional, multi-physics analysis. First, failure mode effects and criticality analysis (FMECA) was conducted to extract the major failure and degradation factors of an I-mast structure and TRM under the vessel’s vibrating and operating conditions. To quantitatively assess the risk priority number (RPN), we propose the use of design of experiments (DoE) and analysis of variance (ANOVA). To preprocess the vibration acceleration signals, principal component analysis (PCA) was used to identify major features from statistical multi-components. Subsequently, based on the diagnosis of fault states, the prediction of remaining useful life (RUL) of I-mast and TRM has been discussed in the context of PHM.
통합마스트 적용을 위한 컨포멀 어레이 빔 합성 기법에 관한 연구
김영완(Kim Youngwan),라영은(Ra Young-eun),이종학(Lee Jonghak),박종국(Park Jongkuk) 한국전기전자학회 2020 전기전자학회논문지 Vol.24 No.2
본 논문에서는 컨포멀 어레이(Conformal Array) 빔 합성 기법에 관한 연구를 수행하였다. 일반적인 선형 배열에서의 빔 조향에 따른 성능 열화 없이 빔 조향을 수행할 수 있는 컨포멀 어레이는 다양한 레이다 시스템에 적용되고 있다. 평면형 선형 배열에서의 빔 합성 기법과 달리 컨포멀 배열은 곡면상에 복사소자가 위치하므로 복사소자별로 파면(Wave Front)까지의 위상을 보상해 주어야 한다. 또한 복사소자별 옵셋 각도(Offset Angle)를 계산하여 실제 q빔 합성 시 적용함으로서 정확한 빔 패턴을 예측할 수 있었다. 본 논문에서는 위상 보상 및 옵셋 각도를 계산하여 빔 패턴 합성 시 적용한 후 빔 패턴 비교를 수행하였으며, 수학적인 분석을 통해 성능을 비교하였다. In this paper, a study on beam synthesis technique of conformal array was performed. It is applied to various radar systems that can perform beam steering without deterioration of performance due to beam steering in a general linear arrangement. Unlike the beam synthesis technique in the planar linear array, the conformal array has a radiation element located on a curved surface, so it is necessary to compensate for a difference in length from the radaation element to the wave front surface. In addition, by calculating the offset angle for each radiation element and applying it during actual synthesis, it was possible to predict an accurate beam pattern. In this paper, length compensation and offset angle were calculated and applied to beam pattern synthesis to perform beam pattern comparison, and performance was compared through mathematical analysis.