해설(解說) : 종축 정안정성 비행시험기법 이해

이주하 ( Ju Ha Lee ) 한국항공운항학회 2007 한국항공운항학회지 Vol.15 No.4

When the aircraft is developed, several flight tests are performed including stability and controllability, performance and systems, above all the most important part of the flight test is stability test. Stability test is divided into two parts, static stability and dynamic stability. Static stability of the aircraft is typically defined in terms of its initial tendency to return to equilibrium after a disturbance and not included time concept. One of static stability, longitudinal static stability, was addressed here. The longitudinal static stability was studied from the basic theory to the flight test method and also explained data reduction method throughout the flight test. Finally showed how to meet the specifications such as ROC, FAR and MIL-specifications.

이동로봇의 횡방향 안정성 증대를 위한 기구

정상국(S. G. Jung),최용제(Y. J. Choi) 한국정밀공학회 2004 한국정밀공학회 학술발표대회 논문집 Vol.2004 No.10월

This paper presents the mechanism to increase lateral stability of a mobile robot using an energy stability margin theory. Previous measure of stability used in a wheeled mobile robot has been based on a static stability margin. However, the static stability margin is independent of the height of the robot and does not provide sufficient measure for the amount of stability when the terrain is not a horizontal plane. In this work, the energy stability margin theory, which is dependent on robot’s height is used to develop a 2 dof mechanism to increase lateral stability. This proposed mechanism shifts the center of gravity of the robot to the point where the energy stability margin is maximized and overall stability of the robot equipped with this mechanism will be increased.

항공기 세로축 무게중심의 변화에 따른 민감도 해석에 관한 연구

김종섭(Chong-sup Kim) 한국항공우주학회 2006 韓國航空宇宙學會誌 Vol.34 No.6

현대의 고성능 전투기는 공력성능 및 조종성능의 향상을 위하여 대부분 세로축 방향으로 항공기를 불안정하게 설계하는 정안정성 완화 개념을 채택하고 있다. 비행제어법칙의 설계 작업은 불안정하게 설계된 항공기에 안정성을 부여하고, 주어진 비행임무에 대하여 만족스 런 조종성능을 발휘할 수 있도록 비행성능을 조작하는 일련의 과정이다. 세로축 무게중심은 무장형상, 연료상태 및 착륙장치의 위치에 영향을 받으며 항공기 안정성에 많은 영향을 미친다. 따라서 무게중심의 이동은 세로축 안정도 여유에 영향을 미친다. 본 논문에서는 운용 시에 발생 가능한 최대 후방 무게중심에 대해 항공기 안정성을 해석하였고, 비행시험을 통 해 최종적으로 검증하였다. 선형해석 항목은 세로축 단주기 모드 특성 및 안정도 여유에 관하여 행하였으며, 비선형 해석 항목은 단주기 모드를 해석하기 위해 세로축 가진 입력에 대 한 항공기 응답특성을 분석하였다. 또한, 최대 후방 무게중심에서 수행된 고받음각 비행시험 자료를 제시함으로써 T-50 고등훈련기의 비행 안정성을 제시하였다. An advanced method of Relaxed Static Stability (RSS) is utilized for improving the aerodynamic performance of modem version supersonic jet fighter aircraft. The flight control system utilizes RSS criteria in longitudinal axis to achieve performance enhancements and improve stability. The flight control law of T-50 advanced trainer employs RSS concept in order to improve the aerodynamic performance and guarantee aircraft stability. The longitudinal center of gravity(X-c.g) varies as a function of external stores, fuel state and gear position. Shifts in X-c.g relate directly to longitudinal static margin in aircraft stability. This paper deals the maximum aft X-c.g for critical aircraft loadings and checks static margin limits using sensitivity such as damping, natural frequency, gain and phase margin. And nonlinear analysis was conducted for such as short period input. And also, this paper shows the T-50 aircraft stability based on the result of high angle of attack flight such as upright and inverted departure.

Analysis of the Static and Dynamic Stability Properties of the Unmaned Airship

Lee, Hae Chang The Korean Society for Aeronautical and Space Scie 2001 International Journal of Aeronautical and Space Sc Vol. No.

The purpose of this paper is to analyze the static and dynamic stability-of the unmanned airship under development ; the target airship's over-all length of hull is 50m and the maximum diameter is 12.5m. For the analysis, the dynamic model of an airship was defined and both the nonlinear and linear dynamic equations of motion were derived. Two different configuration models (KA002Y and KA003Y) of the airship were used for the target model of the static stability analysis and the dynamic stability analysis. From the result of analyses, though the airship is unstable in static stability, dynamic characteristics of the airship can provide the stable dynamic stability. All of the results, airship models and dynamic flight equations will be an important basement and basic information for the next step of developing the automatic flight control system(AFCS) and the stability augmentation system(SAS) for the unmanned airship as well as for the stratospheric airship in the future.

Joined-Wing을 갖는 태양광 발전 하이브리드 비행기의 세로 안전성에 관한 연구

김대원,허현우,유선상,김두만,이희우 한국항공우주학회 2011 한국항공우주학회 학술발표회 논문집 Vol.2011 No.11

항공기의 정적세로안정성은 항공기 설계에서 가로 및 방향 안정성 보다 크게 고려되어지는 부분이다. 이러한 정적세로안정성은 항공기 운항 중 작용하는 다양한 힘과 모멘트에 의해 발생되는 피칭 모멘트에 주로 영향을 받는다. 본 연구에서는 joined wing을 적용한 태양광 발전 항공기의 개발에 있어서 개념설계 후 설계된 항공기의 공력 해석을 통해 항공기의 받음각 변화에 따른 공력 특성과 피칭 모멘트 선도를 바탕으로 세로안정성 문제점을 파악하였다. 이를 바탕으로 세로 안정성의 문제를 보안하기 위하여 Canard를 항공기에 적용하고 2차 공력해석을 통한 공력 특성과 피칭 모멘트 결과를 분석하여 Canard가 적용된 joined wing 태양광 발전 비행기의 세로 안정성을 개선하였다. In aircraft design, the static longitudinal stability of the aircraft is largely considered than lateral and directional stability. The static longitudinal stability is determined various forces and moments acting on aircraft in operation. In this study, The aerodynamic analysis of aircraft obtained by the conceptual design for the development of solar powered hybrid aircraft with joined wing. Aerodynamic characteristics and pitch moment based on the longitudinal stability problems were identified. We analyze second model which be attached canard for solving problem. In conclusion, second model was improved static longitudinal stability

Static Stability Analysis of Single-Layer Reticulated Spherical Shell with Kiewitt-Sunflower Type

Peng Yu,Weijing Yun,Stéphane Bordas,Sheng He,Yiming Zhou 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.5

In this study, we use a large-scale parameter analysis and linear regression method to characterize the static stability of Kiewitt-sunfl ower-type single-layer reticulated spherical shell. Based on more than 15,000 numerical cases of elastic–plastic load–displacement process, and the investigations on the infl uence of buckling and instability mode, rise-span and ringnumbers ratio, effi ciency of the structure, load distribution, support conditions, size of the initial geometric imperfection and distribution patterns are proceeded. We summarize the key eff ect for stable performance of structure, and develop the formulation to calculate the ultimate capacity of stability. The results show that Kiewitt-sunfl ower type single-layer reticulated spherical shell is sensitive to defect, and diff erent distribution patterns of geometry defect lead to diff erent structural buckling. The ultimate stability bearing capacity can be improved by increasing the rise-span and ring-numbers ratio. The asymmetrical load distribution has little eff ect on the stability. The most unfavorable eigenmode is arbitrary, and it is generally not the lowest order. We summarize the key eff ect for stable performance of structure, and develop the formulation to calculate the ultimate capacity of stability.

단기성 점진 부하 운동에 의한 피로유발이 동적 및 정적 자세안정성의 변화와 회복시간에 미치는 영향

김형돈(Hyung Don Kim),이강구(Kang Koo Lee),이재석(Jai Seok Lee) 한국사회체육학회 2009 한국사회체육학회지 Vol.0 No.38

The purpose of this study was to evaluate the effects of fatigue induced by short period of strenuous exercise performed on motor driven treadmill on postural control in healthy college aged male students. The design of this study was an longitudinal cross over design which implements the static and dynamic stability test to the same subjects giving 7 day interval. The subjects consist of 6 competitive gymnasts, 10 non-competitive recreational gymnasts, and 10 non-athletes. Participants completed BESS and SEBT test before maximal aerobic exercise on the treadmill using Bruce protocol. During the maximal aerobic test cardiorespiratory function was measured by Quark b2(Cosmed, USA) respiratory gas analyzer. After completion of aerobic test the participant repeated BESS and SEBT test in the separate session. The data collected were analyzed by SPSS statistical package using descriptive statistics, one way and two way repeated measure ANOVA with 0.05 significance level. The results showed that the knee extension and flexion peak torque were not statistically related to static and dynamic stability. Bone mineral density of non-dominant leg was also not related to static and dynamic stability. After fatigue error score of BESS test significantly increased but group difference did not exist within trial. The gymnasts and recreational gymnasts returned to baseline BESS score in 13 minutes after fatigue. However there was significant difference in SEBT test among the three group which means that gymnasts returned to baseline SEBT score faster than recreational gymnasts and non-athletes. In conclusion postural control was negatively affected after aerobic exercise protocols and the static postural control after fatigue does not respond to the length of previous athletic competition experience. However, dynamic postural control is affected by the length of previous athletic competition experience and elite gymnasts showed better recovery to baseline than the recreational gymnasts and non-athletes.

Stability analysis of a novel mobile spray-painting robot for touch-up painting in vehicle repair plant

Ruijie Zhang,Jun Wu,Yutian Wang 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.5

The stability of a mobile robot is important because it may tip over. This work proposes a hybrid spray-painting robot with high stiffness for touch-up painting in vehicle repair plant and investigates its stability. The distribution of the center of mass is studied based on the kinematics model, and the static stability of the mobile spray-painting robot is analyzed. A micro element method is proposed to accurately calculate the inertia force and the action point of each link in the robot. Zero-moment point (ZMP) is calculated, and the dynamic stability of the mobile robot is assessed using the ZMP criterion. The smallest reasonable width of AGV is obtained for the lightweight design of the robot. The static and dynamic stabilities of the mobile robot are compared with a traditional series mobile robot with the same workspace. Several case studies are conduct by ADAMS to verify the theoretical analysis.

Lift & Cruise Type 충북형 UAM의 정적안정성 분석

김영민,김진영,배효길,임동균 제어·로봇·시스템학회 2024 제어·로봇·시스템학회 논문지 Vol.30 No.2

The Chungbuk UAM, a Lift & Cruise type Urban Air Mobility vehicle, is designed primarily for operation in Chungcheongbuk-do. In wind tunnel testing, the Chungbuk type UAM exhibited unstable directional stability, a component of static stability. This instability was believed to be due to the vortex generated by the canard wing and pod, which submerges the vertical tail wing and diminishes the rudder effect, leading to unstable directional stability. To mitigate this issue, ventral fins were installed, and a comparative analysis was performed to evaluate the impact of the ventral fins’ presence. The optimal configuration of the ventral fins were determined by analyzing the angle between the fins. This study also involved an aerodynamic analysis and comparison of static before and after increasing the area of he vertical tail, aiming to enhance directional stability.

키네시오 테이핑을 적용한 발목 안정화운동이 정적·동적 균형에 미치는 효과

홍수진,김나영,김선하,박성연,이연정,전예원,정승연,정진영,조현정,김정자,Su-Jin Hong,Na-Young Kim,Sun-Ha Kim,Sung-Yeon Park,Yeon-jung Lee,Ye-Won Jeon,Seung-Yeon Jung,Jin-Young Jeong,Hyeon-Jeong Jo,Jeong-Ja Kim 한국임상보건과학회 2023 한국임상보건과학회지 Vol.11 No.1

Purpose: The purpose of this study was to investigate the effect of kinesio taping application on static and dynamic balance during ankle stabilization exercise. Method: H University in Gunsan is recruiting subjects with unstable ankles (N=12). The 12 subjects were randomly divided into groups (n=6) that performed ankle stabilization exercises by applying kinesio taping and groups that performed ankle stabilization exercises only (N=6). Exercise was done twice a week for 4 weeks. All groups conducted the same exercise program, including stretching, for 40 minutes. The exercise program was conducted in the following order. It was conducted in the order of 5 minutes of stretching, 30 minutes of exercise program, and 5 minutes of finishing stretching. To measure the change in static and dynamic balance, the experimenter and control group measured the change by conducting the Cumberland ankle instability tool, the Y-balance test, and the Stork balance standing test (SBST). Results: There was a statistically significant difference in static and dynamic balance between the group with kinesio taping (experimental group) and the group without kinesio taping (control group) in patients with chronic ankle instability. However, there was no statistically significant difference in static and dynamic balance before and after intervention between groups. Conclusion: These results were expected to help improve dynamic and static balance in ankle instability when applying kinesio taping and balance exercises, but there was no significant difference between the experimental group and the control group because the experiment period was short.