• 제어로봇시스템학회:학술대회논문집
• /
• 1992.10a
• /
• pp.680-685
• /
• 1992

Solar arrays and antennas of the satellite are usually stowed within the dimensions of the launch-vehicle fairing and deployed in the orbit. To solve such multibody dynamic problems, differential equations and algebraic equations are simultaneously solved, and special solution techniques are required. In this paper, Lagrange multipliers associated with the constraints are iteratively computed by monotonically reducing an appropriately defined constraint error vector, and the resulting equation of motion is solved by a well-established ODE technique. Defomable bodies as well as rigid bodies are treated, and applications to satellite solar arrays are explained.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2000.10a
• /
• pp.37-38
• /
• 2000

멸치초망어업의 조업방식은 챗대 2개, 콧대 1개를 사용하여 조업선의 우현에서 그물을 수중 전개시키며, 양망은 주기관에 연결된 사이드 드럼 2개를 사용하여 큰 챗대와 작은 챗대를 반 기계적으로 들어올리고, 콧대와 그물은 순수 인력으로 들어올린다. 이와 같은 작업은 야간에 수 차례 반복되기 때문에 많은 노동력과 조업인원을 필요로 하는 노동집약형 구조를 가지고 있다. (중략)

• Journal of the Korea Institute of Military Science and Technology
• /
• v.13 no.3
• /
• 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.

• The Bulletin of The Korean Astronomical Society
• /
• v.34 no.1
• /
• pp.177.1-177.1
• /
• 2009

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.31 no.9
• /
• pp.38-45
• /
• 2003

This research is concerned with the dynamic modeling of the multi-purpose satellite with deployable solar arrays equipped with strain energy hinges(SEH). To this end, we proposed the use of the equivalent torsional spring for the SEH and derived the equations of motion assuming that the satellite and solar arrays are being rigid. We also considered the effect of the support string for the ground experiment model, which has been observed as a critical factor affecting the deployment in the ground experiments. From the numerical simulation results, it is found that solar arrays are deployed in a similar pattern but the hub motions are different because of the support strings. It was concluded that the non-gravity deployment of the solar arrays can be approximately simulated by the ground experimental facility. The effects of the support string are also investigated by varying the length of the string. It was found that the current length of the string is adequate for the ground experiment. Ground experimental results will follow.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.44 no.3
• /
• pp.228-239
• /
• 2016

CNUSAIL-1 is a 3U-sized cube satellite with $4m^2$ small solar sail which is currently being developed at the Chungnam National University. The primary purpose of the CNUSAIL-1 is successful sail deployment in LEO and its operation for investigating its effect on satellite orbit and attitude as well as performing de-orbiting using the sail membranes as drag sail at the final phase. The system design and mechanism of solar sail deployment is introduced, and optical and tensile tests are carried out for the material of membranes and booms for its safety and performance verification. The ground test is carried out to verify its performance for sail deployment and satellite through comparison between folding methods by determining its folding patterns, thickness of spiral spring and angular velocity measurement in a low-friction environment.

• Journal of Aerospace System Engineering
• /
• v.13 no.5
• /
• pp.94-101
• /
• 2019

The dynamic characteristics of the composite reflector panels are numerically and experimentally investigated. A dynamics model of the panel is analytically developed based on a deployment mechanism of the antenna. The deployment is passively activated using elastic energy of a spring with two rotational degrees of freedom. Using the flexible multi-body dynamic analysis ADAMS, dynamic behavior of the panels such as velocities, deformations, as well as reaction forces during the deployment, are investigated in the gravity and zero-gravity cases. The reflector panel is manufactured using carbon fiber reinforced plastics (CFRPs) and its deployment characteristics are experimentally observed using a zero-gravity deployment test. The impact response and vibration problems that occur during deployment of the antenna panel have been identified and reliably deployed using dampers.

• Journal of Aerospace System Engineering
• /
• v.17 no.2
• /
• pp.86-93
• /
• 2023

Pyrotechnic separation devices have been widely used as holding and release mechanism for deployable appendage. However, pyro-shock can cause temporal or permanent damage on shock sensitive components such as electronics, mechanism, and brittle components. This study proposed a low-stiffness blade based passive shock absorber using a multi-layered stiffener laminated with viscoelastic acrylic tapes for reducing transmitted pyro-shock upon explosion of pyrotechnic separation devices. The multi-layered structure with viscoelastic tape has high-damping characteristics to effectively secure structural integrity of low-stiffness blades under the launch environment. The design effectiveness was verified through a shock test by dropping a pendulum. The structural integrity of the shock absorber under a launch environment was evaluated through structural analysis under load conditions with a deployable payload.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.32 no.4
• /
• pp.242-251
• /
• 2020

In this study, the extraction efficiency and reflection coefficient by a two-dimensional OWC (Oscillating Water Column) WEC (wave energy converter) installed in front of a seawall was investigated for regular/irregular waves. The matched eigenfunction expansion method (MEEM) based on the linear potential theory was applied as an analytical tool. The diffraction problem by the incident wave in the open-chamber and the radiation problem by the oscillating pressure in the closed-chamber were solved to obtain the volume fluxes at the internal free-surface. Applying the volume fluxes into the continuity equation for the airflow in a chamber, we got the oscillating air pressure. The maximum extracted power and corresponding reflection coefficient were determined at the optimal turbine coefficient that maximizes the extracted power. OWC device designed for a high extracted efficiency simultaneously contributes to reduce reflected waves.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 1995.04a
• /
• pp.136-140
• /
• 1995

본 연구에서는 생산프로세스의 효율적인 실행을 위해 생산설비의 고장, 가공상이 에러, 예기치 못한 이상상태 발생에 유연한 대처능력을 보유한 고기능 자율가공시스템을 설계하였다. 특히 본 시스템은 자율적으로 프로세스 전개를 지원할 수 있도록 CNC 제어장치의 정보처리 기능을 고도화하고, 각 제어장치가 Local로 의사결정을 하면서 가공에서 검사, 운반등의 생산모듈이 서로 분산 협조제어가 이루어지는 자율분산형 제어기술을 도입/적용하였다.