• Aerospace Engineering and Technology
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• v.1 no.2
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• pp.11-18
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• 2002

The structural load analysis of 50m class airship was performed. The airship maneuver condition for analysis was defined. Aerodynamic, inertia and buoyance models were built. Control surface motion to make defined maneuver condition were calculated. Load factors, load, shear and bending moment envelops were developed for full airship and tailwing. Gondola design loads were developed.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.1
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• pp.98-110
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• 2015

Recently, a validation research of maneuvering and attitude control logics of a spacecraft under a ground condition is getting increase by using operating simulators with compact and precise components. For that, a cold gas propulsion system is generally used for maneuvering and attitude control of spacecraft ground simulators for its simplicity and a high reliability. In the present study, major design parameters of a cold gas propulsion system are derived to meet mission requirements based on conceptual design results of a simulator. And additionally, commercial components with proper specifications are selected for system assembly.

• Journal of Aerospace System Engineering
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• v.13 no.3
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• pp.70-77
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• 2019

This study presents the numerical investigation of the trajectory of rocket launched from a helicopter. The nonlinear mathematical model of armed configuration of UH-60 helicopter was developed while Hydra 70 unguided rocket was modeled to simulate the rocket behavior. The effects of various inflow models on the launched rocket trajectory are obtained. Similarly, rocket launch simulation was performed to determine the unsafe flight maneuver condition where the rocket trajectory is critically close to the helicopter main rotor tip path plane.

• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.3
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• pp.341-352
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• 2019

LTV(Light Tactical vehicle) operating in our military requires higher levels of performance and durability to withstand harsher conditions than ordinary vehicles, as they must travel on both rough-train and off-road as well as on public roads. Recently, developed light tactical vehicle is developed by a variety of test evaluations in order to satisfy ROC(Required Operational Capability) by the requirement military group. However, there is no standardized driving test condition for satisfying the durability performance of Korean tactical vehicle. Therefore, this study aims to provide basic data to establish reliable driving test conditions by analyzing the maneuver conditions and the driving data in order to select the representative drive course required. To do this, we analyzed the future operational environment, the area of operation analysis and the driving information of light tactical vehicle.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.3
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• pp.225-231
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• 2020

Recently, there has been an increasing demand for SAR satellite as it can be operated regardless of the weather condition. In general, main reflector of the SAR is formed of multiple deployable panels to increase performance in the constrained payload envelope. By nature, deployable structure lacks structural stiffness and it is vulnerable to external disturbances and excitation. In particular, SAR satellites may have high levels of vibration occurring at the antenna reflecting surface due to higher angular rate requirements. During image capturing it is important to keep high surface accuracy of the reflector for the quality of images. In this research, a performance degradation of deployable SAR antenna due to structural deformation is analyzed. Panels for main reflectors are assumed to be flexible structures and multi-body simulation environment is established. Then, deflection of the panel is calculated while the satellite performs maneuvers. In addition, antenna gain and beam pointing error are analyzed to determine how these deflections affect antenna performance and mission.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.9
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• pp.773-780
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• 2015

In this paper, the structural integrity for a cylindrical vehicle in subsonic environments is verified. In order to confirm static structural safety for the cylindrical vehicle in extreme maneuver condition, the structure analysis and full-scale static structure test are carried out. The commercial finite element codes, MSC. Patran/Nastran is used for numerical simulation. The full-scale static structure test equipment consists of the counterbalance system, loading system and data acquisition system. Besides, the dynamic characteristics for the cylindrical vehicle are reviewed by performing an impact hammer test.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.3
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• pp.945-953
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• 2018

In this paper, we use 3-D LIDAR for obstacle detection and avoidance maneuver for autonomous unmanned operation. It is aimed to avoid obstacle avoidance in unmanned water under marine condition using only single sensor. 3D lidar uses Quanergy's M8 sensor to collect surrounding obstacle data and includes layer information and intensity information in obstacle information. The collected data is converted into a three-dimensional Cartesian coordinate system, which is then mapped to a two-dimensional coordinate system. The data including the obstacle information converted into the two-dimensional coordinate system includes noise data on the water surface. So, basically, the noise data generated regularly is defined by defining a hypothetical region of interest based on the assumption of unmanned water. The noise data generated thereafter are set to a threshold value in the histogram data calculated by the Vector Field Histogram, And the noise data is removed in proportion to the amount of noise. Using the removed data, the relative object was searched according to the unmanned averaging motion, and the density map of the data was made while keeping one cell on the virtual grid map. A polar histogram was generated for the generated obstacle map, and the avoidance direction was selected using the boundary value.