• 반도체디스플레이기술학회지
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• 제13권1호
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• pp.27-33
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• 2014

Video from unmanned aerial vehicle (UAV) is influenced by natural environments due to the light-weight UAV, specifically by winds. Thus UAV's shaking movements make the video shaking. Objective of this paper is making a stabilized video by removing shakiness of video acquired by UAV. Stabilizer estimates camera's motion from calculation of optical flow between two successive frames. Estimated camera's movements have intended movements as well as unintended movements of shaking. Unintended movements are eliminated by smoothing process. Experimental results showed that our proposed method performs almost as good as the other off-line based stabilizer. However estimation of camera's movements, i.e., calculation of optical flow, becomes a bottleneck to the real-time stabilization. To solve this problem, we make parallel stabilizer making average 30 frames per second of stabilized video. Our proposed method can be used for the video acquired by UAV and also for the shaking video from non-professional users. The proposed method can also be used in any other fields which require object tracking, or accurate image analysis/representation.

• 한국측량학회지
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• 제35권1호
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• pp.1-10
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• 2017

An UAV (Unmanned Aerial Vehicle) is a flight system that is designed to conduct missions without a pilot. Compared to traditional airborne-based photogrammetry, UAV-based photogrammetry is inexpensive and can obtain high-spatial resolution data quickly. In this study, we aimed to classify the land cover using high-spatial resolution images obtained using a UAV. An RGB camera was used to obtain high-spatial resolution orthoimage. For accurate classification, multispectral image about same areas were obtained using a multispectral sensor. A DSM (Digital Surface Model) and a modified NDVI (Normalized Difference Vegetation Index) were generated using images obtained using the RGB camera and multispectral sensor. Pixel-based classification was performed for twelve classes by using the RF (Random Forest) method. The classification accuracy was evaluated based on the error matrix, and it was confirmed that the proposed method effectively classified the area compared to supervised classification using only the RGB image.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.600-603
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• 2004

UAV (Unmanned Aerial Vehicle) is an aerial vehicle that can accomplish the mission without pilot. UAV was developed for a military purpose such as a reconnaissance in an early stage. Nowadays usage of UAV expands into a various field of civil industry such as a drawing a map, broadcasting, observation of environment. These UAV, need vision system to offer accurate information to person who manages on ground and to control the UAV itself. Especially LOS(Line-of-Sight) system wants to precisely control direction of system which wants to tracking object using vision sensor like an CCD camera, so it is very important in vision system. In this paper, we propose a method to recognize object from image which is acquired from camera mounted on gimbals and offer information of displacement between center of monitor and center of object.

• 대한원격탐사학회지
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• 제31권3호
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• pp.215-226
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• 2015

일반적으로 UAV를 이용한 항공촬영은 약 430 MHz 대역폭의 radio frequency (RF) 모뎀을 이용하여 UAV와 지상관제시스템간의 연결을 통해 UAV의 통제 및 원격 조종을 한다. 기존의 방법을 이용한 경우 1~2 km 정도의 통신 범위를 가지고 있으며 잦은 혼선이 일어나고, 무선통신은 전파를 매개로 정보를 전달하기 때문에 신호세기를 10 mW로 제한을 두고 있어 장거리 통신을 하는데 제약이 있었다. 본 연구에서는 스마트 카메라의 long-term evolution (LTE), 블루투스, WiFi와 같은 무선 데이터 통신 기술을 이용하여 데이터 송수신이 가능한 통신 모듈 시스템과 카메라를 이용하여 영상 획득이 필요한 지역에서 UAV에 영상을 획득하는 자동촬영 시스템을 설계하고 개발하는데 그 목적은 둔다. 본 연구에서 제안한 안드로이드 기반의 UAV 촬영 및 통신모듈시스템은 스마트 카메라 하나로 영상 획득뿐만 아니라 UAV 시스템과 지상관제 시스템을 연결해주며, UAV 시스템의 GPS와 자이로스코프, 가속도계, 자기 계측 센서 등의 센서로 부터 획득된 3차원 위치정보와 3차원 자세정보를 실시간으로 제공받을 수 있어서 항공삼각측량을 통한 UAV의 위치 및 보정 작업에 실시간으로 이용될 수 있을 것으로 판단된다.

• 한국초지조사료학회지
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• 제35권3호
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• pp.225-231
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• 2015

Improving current pasture productivity by precision management requires practical tools to collect site specific pasture biomass data. Recent developments in unmanned aerial vehicle (UAV) technology provide cost effective and real time applications for site specific data collection. For the mapping of herbage biomass (BM) on a hill pasture, we tested a UAV system with digital cameras (visible and near-infrared (NIR) camera). The field measurements were conducted on the grazing hill pasture at Hanwoo Improvement Office, Seosan City, Chungcheongnam-do Province, Korea on May 17 and June 27, 2014. Plant samples were obtained from 28 sites. A UAV system was used to obtain aerial photos from a height of approximately 50 m (approximately 30 cm spatial resolution). Normalized digital number (DN) values of Red and NIR channels were extracted from the aerial photos and a normalized differential vegetation index using DN ($NDVI_{dn}$) was calculated. The results show that the correlation coefficient between BM and $NDVI_{dn}$ was 0.88. For the precision management of hilly grazing pastures, UAV monitoring systems can be a quick and cost effective tool to obtain site-specific herbage BM data.

• 한국항공우주학회지
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• 제37권12호
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• pp.1209-1216
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• 2009

본 논문에서는 실내 공간에 설치된 복수의 카메라로부터 획득한 영상정보를 소형무인기의 자세 추정 및 제어에 이용하는 시스템에 대한 연구를 기술하였다. 제안된 시스템은 실외 비행시험의 제한을 극복하고 효율적인 비행시험 환경을 구축하기 위한 것으로 무인기의 위치 및 자세를 측정하기 위해 별도의 센서를 탑재할 필요가 없어 저가의 장비로 테스트베드를 구성할 수 있다는 장점을 갖는다. 시스템 구현을 위해 요구되는 카메라 보정, 마커 검출, 자세 추정 기법을 소개하였으며 테스트베드를 이용한 실험 결과를 통해 제안된 방법의 타당성 및 성능을 보였다.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2011년도 전기공동학술대회 논문집
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• pp.284-284
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• 2011

Survivors of accidents in the area to check in. check now people will be direct. To reduce the risk UAV with a camera resolution of the survivors fled afar possible. In addition, a stable control for Kalman filter and PID control was used to Even beginners can easily control the UAV is characteristic.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 추계학술대회 논문집
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• pp.407-412
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• 2009

In the present work, vibration control performance of active camera mount system for unmanned aero vehicle (UAV) is evaluated. An active mount featuring inertia type of piezostack actuator is designed and manufactured. Then, vibration control performances are experimentally evaluated. A camera mount system with four active mounts is constructed and mechanical model is established. The governing equation for the camera mount system is obtained and control model is constructed in state space model. Sliding mode controller which has inherent robustness to external disturbance is designed and implemented to the system. Vibration control performances are evaluated at each mount and center of gravity point. Effective vibration performances are obtained and presented in time and frequency domains.

• 한국소음진동공학회논문집
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• 제19권12호
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• pp.1315-1321
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• 2009

In the present work, vibration control performance of active camera mount system for unmanned aero vehicle(UAV) is evaluated. An active mount featuring inertia type of piezostack actuator is designed and manufactured. Then, vibration control performances are experimentally evaluated. A camera mount system with four active mounts is constructed and mechanical model is established. The governing equation for the camera mount system is obtained and control model is constructed in state space model. Sliding mode controller which has inherent robustness to external disturbance is designed and implemented to the system. Vibration control performances are evaluated at each mount and center of gravity point. Effective vibration performances are obtained and presented in time and frequency domains.

• 한국통신학회논문지
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• 제38C권12호
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• pp.1196-1206
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• 2013

본 논문에서는 PTZ(Pan Tilt Zoom) 카메라를 장착한 무인항공기의 항법장치 정보와 촬영지역의 입체적 지형정보를 기반으로, 무인항공기가 촬영하는 지리적 위치를 실시간으로 파악하고 촬영 지역의 면적을 자동 산출할 수 있는 알고리즘을 제안한다. 또한 제안한 알고리즘과 더불어 특정 지역의 촬영 가능 여부를 자동 판단할 수 있는 방안을 설명한다. 무인항공기가 원하는 특정지역의 촬영을 시도할 경우에는 항공기의 위치와 고도뿐만 아니라 해당 지역의 입체적 지형에 의하여 유효한 영상의 획득 가능여부가 결정된다. 본 연구의 결과를 적용하면 지상관제센터에서 무인항공기가 촬영하는 영상이 원하는 지역의 정보인지 실시간으로 판단할 수 있으므로 정확한 실시간 원격 운항 제어가 가능하다. 그리고 제안한 알고리즘과 촬영가능여부를 판단하는 방안은 사전 모의 운항 및 운항경로 설정에 유용하게 응용할 수 있다.