• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
• /
• pp.27-27
• /
• 2000

The nonlinear observers are proposed for a nonlinear system. To improve the characteristics such as a stability, a convergence, and an H$\sub$$\infty$/ filter performance criterion, we utilize and H$\sub$$\infty$/ filter Riccati equation or a modified H$\sub$$\infty$/ filter Riccati equation with a freedom parameter. Using the Lyapunov, the characteristics of the observer are analyzed. Then the in-flight alignment for a strapdown inertial navigation system(SDINS) is designed using the observer proposed. Simulation results show that the observer with the modified H$\sub$$\infty$/ fitter Riccati equation effectively improve the performance of the in-flight alignment.

• 한국군사과학기술학회지
• /
• 제13권3호
• /
• pp.365-371
• /
• 2010

The fins of a missile which is folded within a canister are deployed according to a command during the missile flight. The aerodynamic load generated by operating environments such as missile flight speed, platform movement speed and wind acts as an anti-deploying force and prevents the fins from deploying. As the diversification of platforms and the higher speed of missiles need a larger deploying force but the space for operating the fin deploying device is getting narrower, the new design concepts are required for developing such a device. In this study, a pneumatic device for deploying missile fins is designed and its characteristics are verified through experiments and analyses.

• 한국항공우주학회지
• /
• 제44권2호
• /
• pp.116-122
• /
• 2016

터보제트 엔진에서 램제트 엔진으로의 작동 천이를 고려한 TBCC엔진의 성능 특성을 연구하였다. 터보제트 엔진과 램제트 엔진의 성능모델을 제시하고 터보제트와 램제트의 작동 비율을 조절하여 성능 변화가 연속적으로 발생하도록 엔진 작동의 천이 모드를 고려하였다. 이를 통해 다양한 마하수와 고도에서의 완만한 엔진 성능 변화를 나타냈음을 확인하였다. 일정고도(11km)와 가상의 비행 궤적에 대하여 천이 모드를 적용하여 TBCC 엔진의 추력과 비추력의 변화를 분석하였으며, 이를 통해 예상 비행 조건과 엔진의 천이 모드를 고려한 성능 변화와 복합 사이클 엔진 작동 천이 모드의 필요성을 제안하였다.

• 한국항공운항학회:학술대회논문집
• /
• 한국항공운항학회 2005년도 춘계학술발표대회 논문집
• /
• pp.112-115
• /
• 2005

• 한국운동역학회지
• /
• 제13권3호
• /
• pp.81-98
• /
• 2003

The purpose of this study is to closely examine kinematic characteristics by jump phase of Li Xiaopeng motion in horse vaulting and provide the training data. In doing so, as a result of analyzing kinematic variables through 3-dimensional cinematographic using the high-speed video camera to Li Xiaopeng motion first performed at the men's vault competition at the 14th Busan Asian Games, the following conclusion was obtained. 1. It was indicated that at the post-flight, the increase of flight time and height and twisting rotational velocity has a decisive effect on the increase of twist displacement. And Li Xiaopeng motion showed longer flight time and higher flight height than Ropez motion with the same twist displacement of entire movement. Also the rotational displacement of the trunk at peak of COG was much short of $360^{\circ}$(one rotation) but twist displacement showed $606^{\circ}$. Likewise, Li Xiaopeng motion was indicated to concentrate on twist movement in the early flight. 2. It was indicated that at the landing, Li Xiaopeng motion gets the hip to move back, the trunk to stand up and the horizontal velocity of COG to slow down. This is thought to be the performance of sufficient landing, resulting from large security of rotational displacement of airborne and twist displacement. 3. It was indicated that at the board contact, Li Xiaopeng motion made a rapid rotation uprighting the trunk to recover slowing velocity caused by jumping with the horse in the back, and has already twisted the trunk nearly close to $40^{\circ}$ at board contact. Under the premise that elasticity is generated without the change of the feet contacting the board, it will give an aid to the rotation and twist of pre-flight. Thus, in the round-oH phase, the tap of waist according to the fraction and extension of hip joint and arm push is thought to be very important. 4. It was indicated that at the pre-flight, Li Xiaopeng motion showed bigger movement than the techniques of precedented studies rushing to the horse, and overcomes the concern of relatively low power of jump through the rapid rotation of the trunk. Li Xiaopeng motion secured much twist distance, increased rotational distance with the trunk bent forward, resulting in the effect of rushing to the horse. 5. At horse contact, Li Xiaopeng motion makes a short-time contact, and maintains horse take-off angle close to vertical, contributing to the increase of post-flight time and height. This is thought to be resulted from rapid move toward movement direction along with the rotational velocity of trunk rapidly earned prior to horse contact, and little shave of rotation axis according to twist motion because of effective twist in the same direction.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2008년 영문 학술대회
• /
• pp.671-679
• /
• 2008

The effect of Pre-cooled Turbojet Engine installation and nozzle exhaust jet on Hypersonic Turbojet EXperimental aircraft(HYTEX aircraft) were investigated by three-dimensional numerical analyses to obtain aerodynamic characteristics of the aircraft during its in-flight condition. First, simulations of wind tunnel experiment using small scale model of the aircraft with and without the rectangular duct reproducing engine was performed at M=5.1 condition in order to validate the calculation code. Here, good agreements with experimental data were obtained regarding centerline wall pressures on the aircraft and aerodynamic coefficients of forces and moments acting on the aircraft. Next, full scale integrated analysis of the aircraft and the engine were conducted for flight Mach numbers of M=5.0, 4.0, 3.5, 3.0, and 2.0. Increasing the angle of attack $\alpha$ of the aircraft in M=5.0 flight increased the mass flow rate of the air captured at the intake due to pre-compression effect of the nose shockwave, also increasing the thrust obtained at the engine plug nozzle. Sufficient thrust for acceleration were obtained at $\alpha=3$ and 5 degrees. Increase of flight Mach number at $\alpha=0$ degrees resulted in decrease of mass flow rate captured at the engine intake, and thus decrease in thrust at the nozzle. The thrust was sufficient for acceleration at M=3.5 and lower cases. Lift force on the aircraft was increased by the integration of engine on the aircraft for all varying angles of attack or flight Mach numbers. However, the slope of lift increase when increasing flight Mach number showed decrease as flight Mach number reach to M=5.0, due to the separation shockwave at the upper surface of the aircraft. Pitch moment of the aircraft was not affected by the installation of the engines for all angles of attack at M=5.0 condition. In low Mach number cases at $\alpha=0$ degrees, installation of the engines increased the pitch moment compared to no engine configuration. Installation of the engines increased the frictional drag on the aircraft, and its percentage to the total drag ranged between 30-50% for varying angle of attack in M=5.0 flight.

• 한국항공우주학회지
• /
• 제41권11호
• /
• pp.849-854
• /
• 2013

본 연구에서는 편대비행하는 고속 항공기의 날개 끝 와류의 공력 간섭 효과를 연구하기 위해서 풍동실험기법이 적용되었다. 편대비행에서 앞선 항공기의 날개 끝에서 발생하는 와류가 뒤따르는 항공기의 공력 특성에 영향을 미칠 수 있다. 흐름의 간섭 효과는 앞선 항공기와 뒤따르는 항공기의 날개 끝 사이의 거리에 따라서 변화된다. 본 연구의 실험결과 앞선 항공기에서 발생되는 날개 끝 와류는 뒤따르는 항공기의 공력 및 모멘트 계수를 변화시킴을 확인하였다. 특히, 후방 항공기의 양력계수는 수직 및 수평 위치에 따라 y/b=-0.125, z/b=0.0에서 가장 많이 증가되거나 y/b=-0.5, z/b=0.38에서 가장 크게 감소됨을 확인하였으며, 두 항공기로부터 발생된 날개 끝 와류의 간섭 현상이 자세히 관찰되었다.

• 한국항공우주학회지
• /
• 제46권10호
• /
• pp.833-844
• /
• 2018

본 연구에서는 무인 회전익기의 종류인 쿼드콥터의 로터 블레이드에 대해 바람 및 비행 조건의 따른 공력특성을 예측하고자 한다. 돌풍 및 비행 조건들을 고려하기 위해 바람의 좌표계 변환 개념을 제시하였다. 강체 블레이드 플래핑 운동방정식을 고려한 깃 요소 및 운동량 이론을 이용해 개별 로터의 제자리, 전진, 상승 비행을 해석하였다. XFOIL을 사용하여 공력결과를 도출하였고, 개발된 BEMT를 이용하여 제자리 비행, 전진, 상승 조건의 검증을 수행했다. 또한 제자리 비행 실험 환경 구축 및 실험 결과와 개발된 BEMT의 비교 및 검증을 수행하였다.

• 한국항공우주학회지
• /
• 제31권9호
• /
• pp.88-93
• /
• 2003

본 논문은 헬리콥터용 시뮬레이션 프로그램 개발에 관한 연구이다. 일반적으로 헬리콥터 비행시뮬레이션에 사용되는 수학모델은 고 충실도를 가져야 한다. 그러므로 시뮬레이션을 실행할 때 보다 정교하 공력 모델이 필요하게 되며, 계산시간이 많이 걸린다. 어떠한 특수 목적을 수행하는 UAV 비행제어시스템에서는 제어기를 설계할 때 사용되는 선형모델을 비선형모델로부터 얻는 시간을 최소화 하는 것이 중요하다. 이와 같은 목적을 달성하기 위한 첫 번째 단계는 실제로 헬리콥터 동특성을 잘 나타내는 비선형 모델을 완성하는 일이다. 두 번째 단계는 비선형방정식으로부터 특정 비행조건에 맞는 트림값을 계산하는 것이다. 그리고 나서 수치적인 방법으로 안정미계수와 조종미계수를 계산하여 특정 비행 상태 조건에 부합하는 선형모델을 구한다. 이러한 과정을 편리하게 처리하는 프로그램을 MATLAB GUI를 사용해서 개발하였다. 이 논문에서 제안된 방법은 기존의 실물크기 모델헬리콥터 시뮬레이션 방법에 비해 간략화된 것이다. 따라서 선형모델을 얻기까지의 연산시간이 짧아서 무인헬리콥터의 비행제어시스템을 설계하는데 유용할 것이다.

• 임상간호연구
• /
• 제19권2호
• /
• pp.218-232
• /
• 2013

Purpose: This study was aimed to describe Helicopter Emergency Medical Services (HEMS) and analyze the flight nurses' activities in HEMS. Methods: Data were collected retrospectively from the air transportation reports that contained data of 168 patients transported by aircraft to G University medical center in Incheon since June, 2012 to March, 2013. Data were analyzed using descriptive statistics, and Mann-Whitney U test. Results: Average distance of flights was 44.0 km, duration of field treatment took 13.6 minutes, and duration of a flight from scene to hospital was 14.5 minutes. Nursing activities were categorized into 12 direct nursing activities and 5 nursing management activities, and a total number of 7806 nursing activities were occurred in HEMS. The most frequently performed nursing activity was measurement and monitoring (27.9%) followed by medication (11.5%) and respiratory management (8.7%). The most frequent nursing management were information management (11.0%). Nursing activities performed were significantly different depending on the patient's level of consciousness, cause of illness, crew configuration, and type of transportation. Conclusion: This study described HEMS nursing activities performed by flight nurses. Difference in nursing activities according to patient characteristics, crew configuration and type of transportation requires flight nurses to be prepared through educational programs to improve nursing activities and nursing management during air transportation.