• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.67-69
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• 2023

유연한 이동성, 쉬운 배치, 저렴한 비용 등의 장점을 가진 Unmanned Aerial Vehicle(UAV)를 이용해 Deep Neural Network(DNN) 서비스를 제공하는 기술이 연구되고 있다. 하지만 UAV 는 메모리와 컴퓨팅 능력, 배터리가 제한되어 있어 DNN 서비스의 요구사항을 만족시키기 위해서는 다수의 UAV간의 협업이 필요하다. 본 논문에서는 다수의 UAV 협업 환경에서 DNN 서비스의 처리 지연시간을 줄이기 위해 UAV 들의 작업량을 고려한 서비스 분산 처리 기법을 제안하고, 시뮬레이션을 통해 DNN 서비스 처리 지연 시간을 분석한다.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.59-61
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• 2004

For automatic landing of small VTOL UAV, it is necessary to calculate the distance from the UAV and the ground. The distance can be generally measured by a ultra-sonic sensor, but the ultra-sonic sensor has errors according to velocity of a sensor board. To compensate these errors, we proposed a sensor fusion method using a Kalman filter.

• 시스템엔지니어링워크숍
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• s.4
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• pp.17-22
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• 2004

This paper present the brief generation process of system requirements or mart UAV from a development obejective. The current Snart UAV requirements deal with the restricted life cycle from development to test and verification exclusive of full life cycle beacuse of the new technology demonstration research program funded by goverments. The Smart UAV system consists of flight vechicle, avionics, communication link, payload, ground control stationand ground supporting system. In thus paper, top-down flown requirememts are intoduced how to allocate to each sub-system.

• Proceedings of the Korea Contents Association Conference
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• 2016.05a
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• pp.295-296
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• 2016

UAV를 이용하여 정사영상과 수치지도제작을 위해서는 촬영계획대로 촬영해야 한다. 그러나 풍속, 풍향 및 시스템의 결함으로 촬영정확도가 저하된다. 저가 UAV의 waypoint기능을 활용한다면 다소 실수를 줄일 수 있다. 본 연구에서는 waypoint기능을 이용하여 비행정확도를 평가하고 모의촬영을 통해 촬영정확도를 확인하고자 한다.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.37-38
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• 2017

최근 방제 및 예찰과 같은 농작업에 단일 UAV(Unmanned Aerial Vehicle)시스템이 적용되고 있지만, 가반하중과 체공시간 등 기존시스템의 문제가 점차 대두되면서 작업 시간을 보다 단축시키고 작업 효율을 극대화 할 수 있는 농업용 멀티 UAV시스템의 필요성이 증대되고 있다. 본 논문에서는 작업자가 다수의 농업용 UAV를 효과적으로 제어할 수 있는 분산군집제어 알고리즘을 제안하며 알고리즘 검증 및 평가를 위한 시뮬레이터를 소개한다. 분산군집제어는 UAV 제어 계층, VP(Virtual Point) 제어 계층, 원격제어 계층으로 이루어진 3계층 제어구조를 가진다. UAV 제어 계층에서 각 UAV는 point mass로 모델링 되는 VP의 이상적인 경로를 추종하도록 제어한다. VP 제어 계층에서 각 VP는 입력 $p_i(t)=u^c_i+u^o_i+u^{co}_i+u^h_i$-(1)을 받아 제어되는데 여기서, $u^c_i{\in}{\mathbb{R}}^3$는 VP 사이의 충돌방지제어, $u^o_i{\in}{\mathbb{R}}^3$는 장애물과의 충돌방지제어, $u^{co}_i{\in}{\mathbb{R}}^3$는 UAV 상호간의 협조제어, $u^h_i{\in}{\mathbb{R}}^3$는 작업자로부터의 원격제어명령이다. (1)의 제어입력에서 충돌방지제어는 각 $u^i_c:=-{\sum\limits_{j{\in}{\eta}_i}}{\frac {{\partial}{\phi}_{ij}^c({\parallel}p_i-p_j{\parallel})^T}{{\partial}p_i}}$-(2), $u^o_c:=-{\sum\limits_{r{\in}O_i}}{\frac {{\partial}{\phi}_{ir}^o({\parallel}p_i-p^o_r{\parallel})^T}{{\partial}p_i}}$-(3)로 정의되면 ${\phi}^c_{ij}$와 ${\phi}^o_{ir}$는 포텐셜 함수를 나타낸다. 원격제어 계층에서 작업자는 햅틱 인터페이스를 통해 VP의 속도를 제어하게 된다. 이때 스케일변수 ${\lambda}$에 대하여 VP의 원격제어명령은 $u^t_i(t)={\lambda}q(t)$로 정의한다. UAV 시뮬레이터는 리눅스 환경에서 ROS(Robot Operating Systems)를 기반한 3차원 시뮬레이터인 Gazebo상에 구축하였으며, 마스터와 슬레이브 간의 제어 명령은 TCPROS를 통해 서로 주고받는다. UAV는 PX4 기반의 3DR Solo 모델을 사용하였으며 MAVROS를 통해 MAVLink 통신 프로토콜에 접속하여 UAV의 고도, 속도 및 가속도 등의 상태정보를 받을 수 있다. 현재 멀티 드론 시스템을 Gazebo 환경에 구축하였으며, 추후 시뮬레이터 상에 분산군집제어 알고리즘을 구현하여 검증 및 평가를 진행하고자 한다.

• Journal of the Korean Association of Geographic Information Studies
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• v.21 no.3
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• pp.162-175
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• 2018

The purpose of this study was to analyze the surface temperature of surface fabrics using UAV TIR images, to mitigate problems in the thermal environment of urban areas. Surface temperature values derived from UAV images were compared with those measured in-situ during the similar period as when the images were taken. The difference in the in-situ measured and UAV image derived surface temperatures is the highest for gray colored concrete roof fabrics, at $17^{\circ}C$, and urethane fabrics show the lowest difference, at $0.3^{\circ}C$. The experiment power of the scatter plot of in-situ measured and UAV image derived surface temperatures was 63.75%, indicating that the correlation between the two is high. The surface fabrics with high temperature are metal roofs($48.9^{\circ}C$), urethane($43.4^{\circ}C$), and gray colored concrete roofs($42.9^{\circ}C$), and those with low temperature are barren land($30.2^{\circ}C$), area with trees and lawns($30.2^{\circ}C$), and white colored concrete roofs($34.9^{\circ}C$). These results show that accurate analysis of the thermal characteristics of surface fabrics is possible using UAV images. In future, it will be necessary to increase the usability of UAV images via comparison with in-situ data and linkage to satellite imagery.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.2
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• pp.3-9
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• 2014

With broadcasting telecommunication, rapid change detection, and construction of spatial information, a long reconnaissance, resources detection in dangerous area and natural disasters, which are difficult for manned aerial vehicles to perform, international recognition in UAV merely being used for limited military purposes has been changed and its demand for both civil and military purpose have been increased. However, considering the current situation that availability of UAV varies and its working areas also broaden, the stability of UAV and the problems of privacy protection are more important in integrated operation of UAV. In particular, the application of UAV system is urgent for the area where rapid decision making due to expedite data construction such as disaster, calamity, and the acquisition of spatial information for small area are required. However, since technical stability for UAV system and institutional regulation in regard of spatial information are not examined, and UAV system has not been integrated with aerial photograph, the limitation of UAV system has been presented. Thus, this study is aimed at analyzing domestic and foreign research trend and institutional research trend in terms of integrated UAV operation, and proposing its implications and the availability of integrated UAV operation for future national spatial information data construction.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.5
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• pp.444-450
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• 2015

The accuracy of small and low cost CCD camera is insufficient to provide data for precisely tracking unmanned aerial vehicles(UAVs). This study shows how UAV can hover on a human targeted tracking object by using CCD camera rather than imprecise GPS data. To realize this, UAVs need to recognize their attitude and position in known environment as well as unknown environment. Moreover, it is necessary for their localization to occur naturally. It is desirable for an UAV to estimate of his attitude by environment recognition for UAV hovering, as one of the best important problems. In this paper, we describe a method for the attitude of an UAV using image information of a maker on the floor. This method combines the observed position from GPS sensors and the estimated attitude from the images captured by a fixed camera to estimate an UAV. Using the a priori known path of an UAV in the world coordinates and a perspective camera model, we derive the geometric constraint equations which represent the relation between image frame coordinates for a marker on the floor and the estimated UAV's attitude. Since the equations are based on the estimated position, the measurement error may exist all the time. The proposed method utilizes the error between the observed and estimated image coordinates to localize the UAV. The Kalman filter scheme is applied for this method. its performance is verified by the image processing results and the experiment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.11
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• pp.1557-1565
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• 2016

The UAV systems working in difficult environment should be able to performs various actions autonomously required to achieve the given mission without the human interventions. However, the actual tests for such UAV system will take heavy cost. Thus, the simulation test in advance before the actual test is important. This paper proposes a 3D visual simulation environment for autonomous agent-based UAV systems. The several simulation tests performed on the rescue scenarios will demonstrate our techniques.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.6
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• pp.517-525
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• 2007

As usage of UAV becomes more common, a basic requirements on the system are changing. Existent system did function embodiment by major object, but current UAV puts bigger weight to availability. Therefore, all the advanced countries in UAV technologies put great efforts in reliability analysis techniques and source collection of system, and reflect the result in design. The authors are developing a flight control system for a UAV and using the reliability analysis techniques in the process. This paper introduces basic reliability analysis techniques and results of analysis for a small UAV flight control system that is developing present. The result plans efficiency enlargement UAV development and operation process.