• Journal of Advanced Navigation Technology
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• v.15 no.2
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• pp.181-188
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• 2011

A small UAVs(Unmaned Aerial Vehicles) have limited by the payload capacity which requires miniaturization of a navigation system. In this paper, the performance of the lightweight and small sized AHRS(Attitude Heading Reference System), which is self-developed, is evaluated at low acceleration environment. The designed AHRS adopts the commercial low-cost MEMS sensors. A quaternion-based attitude calculation method, which eliminates singularity with relatively simple algebra, is used. In an attitude correction algorithm, the Kalman filter is used with accelerometers and magnetometers combined. The fabricated AHRS is also evaluated with reference to a COTS(Commercial Off-The-Shelf) AHRS which reports a number of successful applications to a small UAVs. The test results show that the measurements from the fabricated AHRS provide proper attitude output data with acceptable amount of differences(horizontal axis 0.5$^{\circ}$, vertical axis 1.5$^{\circ}$) in test environment.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.11
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• pp.908-914
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• 2013

This study has developed a small solar powered UAV and performed its flight tests. In daylight, a solar powered UAV flies by using some of electricity generated from solar cells, and stores the remainder into battery. At night it flies by using electricity from battery. A solar powered UAV should have aerodynamically efficient configurations, light-weight, strong wing and fuselage. Its electric propulsion system and solar power system should also be very efficient. In the present study the solar powered UAV and its solar power system are developed for 12 hour continuous flight and the flight tests are performed to verify its performance. The flight tests performed in fall and winter to prove the present solar powered UAV is successful in four-season 12 hour flight.

• Journal of Convergence for Information Technology
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• v.7 no.3
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• pp.27-36
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• 2017

In almost industries, such as the logistics industry, marine fisheries, agriculture, industry, and services, small unmanned aerial vehicles are used for aerial photographing or closing flight in areas where human access is difficult or CCTV is not installed. Also, based on the information of small unmanned aerial photographing, application research is actively carried out to efficiently perform surveillance, control, or management. In order to carry out tasks in a mission-based manner in which the set tasks are assigned and the tasks are automatically performed, the small unmanned aerial vehicles must not only fly steadily but also be able to charge the energy periodically, In addition, the unmanned aircraft need to land automatically and precisely at certain points after the end of the mission. In order to accomplish this, an automatic precision landing method that leads landing by continuously detecting and recognizing a marker located at a landing point from a video shot of a small UAV is required. In this paper, it is shown that accurate and stable automatic landing is possible even if simple template matching technique is applied without using various recognition methods that require high specification in using low cost general purpose small unmanned aerial vehicle. Through simulation and actual experiments, the results show that the proposed method will be made good use of industrial fields.

• Journal of the Korean Geographical Society
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• v.50 no.5
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• pp.473-483
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• 2015

In a coastal area, a plenty of research has adopted remotely sensed data. This is because longterm interaction between land and ocean makes continuous geographical changes in a broad extent and unaccessible areas. However, conventional remote sensing platforms such as satellite or airplane has several disadvantages including limited temporal resolution and high operational costs. Hence, this study uses a UAV system to detect a coastline and its movement. Result of coastline detection shows how the coastline moves in a day. Time-series coastlines were derived from UAV aerial images through digital image processing. There is a drawback in the stability of UAV compared to the conventional remote sensing platform, but the advantage appears on the economical efficiency. Since the latest studies shows an improvement of UAV for a variety of purposes in many fields, a UAV can also be utilized for regional study and spatial data acquisition platform. geography can also utilize a UAV as a spatial data acquisition platform for regional study.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.10
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• pp.912-917
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• 2007

In this paper system identification of a small UAV via neural networks is tried and the estimated parameters are then compared to those obtained by Fourier Transform Regression and Maximum Likelihood Estimation Techniques. With the estimated parameters a linear system is constructed and simulated to compare to the flight data. The results show that parameter identification using neural networks is comparable to the existing techniques

• Defense and Technology
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• no.2 s.240
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• pp.78-87
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• 1999

해상 무인항공기 연구개발은 여러 요소들에 의해 대단히 중요시되고 있는데 그 요소들을 보면 연안 해상 작전에 대한 중요성이 증대되고, 전 세계적으로 많은 국가들의 해군 세력이 중무장한 공격용 소형의 신형 코르벳함들로 등장하고 있으며, 함상탑재용 유인기의 비용이 지나치게 비싸다는 것과 대잠수함전(ASW)에서는 유인기가 매우 중요한 역할을 수행하는 점 때문일 것이다

• Journal of Aerospace System Engineering
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• v.17 no.5
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• pp.34-41
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• 2023

This paper applies the icing effect and wing rock uncertainty to small unmanned aerial vehicles (UAVs), which have recently attracted attention. Attitude control simulations were performed using various control methods. First, the selected platform, the Skywalker X8 UAV with blended wing-body (BWB) configuration, was linearized for both its baseline form, and a form with applied icing effects. Subsequently, using MATLAB SimulinkⓇ, simulations were conducted for roll and pitch attitude control of the baseline configuration and the configuration with icing effects, employing disturbance observer-based PID control, model reference adaptive control, and model predictive control. Furthermore, the study introduced wing rock uncertainty simultaneously with icing effects on the configured model-a combination not previously explored in existing research-and conducted simulations. The performance of each control Method was compared and analyzed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.6
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• pp.461-467
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• 2014

This paper investigates using small UAVs as communications relay nodes for expanding communications links and improving communications quality, primarily for a fleet of ground or navy vessels. An airborne relay in ground/maritime space can effectively connect to units operating over the horizon, beyond normal communication range, or under limited satellite communication environment. Even if the equipment development is mature for communications relay, where to locate UAVs for efficient relay is still a pending question. With this background, this paper will develop high-level deployment algorithms to optimize the location of UAVs for improving the connectivity of a wireless network among a fleet of ground or navy vessels.

• The Korean Journal of Air & Space Law and Policy
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• v.35 no.3
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• pp.65-93
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• 2020

With the development of information and communication technology, the unmanned aerial vehicle industry began to attract attention as a new growth industry as it entered the fourth industrial revolution. As the size of the unmanned aerial vehicles and the scope of airspace vary from small drones to large unmanned aerial vehicles, the developed countries such as USA and Europe are developing plans for the integrated operation of manned and unmanned aerial vehicles. ICAO is also working on amendments to the relevant ICAO annexes to establish international standards and recommendations for unmanned aerial vehicles. Korea also needs to prepare for the integrated operation of manned and unmanned aerial vehicles that will come in the future, and for this purpose, it is necessary to review and revise the national regulation systems for the safe operation of unmanned aerial vehicles. This study analyzes the amendments of related annexes discussed on the Remotely Piloted Aircraft System (RPAS) pannel, and suggests the direction of revision of the Aviation Safety Act for the safe operation of unmanned aerial vehicles in comparison with the existing Aviation Safety Act.

• The Science & Technology
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• s.508
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• pp.23-25
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• 2011