• 항공우주기술
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• 제4권2호
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• pp.7-14
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• 2005

본 논문은 군에서 운용중인 대공포 사격 훈련용으로 개발한 무인 표적기용 자동비행시스템 개발에 관한 논문이다. 조종사에 의해 수동으로 운용중인 표적기를 자동화함으로써 조종사 측면에서는 비행업무를 경감시키고, 군 측면에서는 사격훈련 예산절감이라는 장점을 가지게 된다. 현재까지 개발된 대부분의 UAV(Unmanned Aerial Vehicle)는 항공기 자세를 측정하기 위해 AHRS(Attitude & Heading Reference System)와 IMU(Inertial Measurement Unit)등의 고가의 센서를 장착하고 있지만 이를 장착하고 무인기를 사격훈련용으로 사용하기에는 비용절감이라는 목적에 적합하지 않다. 이에 본 논문은 저가의 센서를 장착하고 자동비행이 가능하도록 저가형 자동비행시스템을 개발하였으며, 비행시험을 통하여 자동비행시스템 성능을 입증하였다.

• 제어로봇시스템학회논문지
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• 제20권12호
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• pp.1189-1195
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• 2014

This paper addresses a Moving Target Indication (MTI) algorithm which can be used for small Unmanned Aerial Vehicles (UAVs) equipped with image sensors. MTI is a system (or an algorithm) which detects moving objects. The principle of the MTI algorithm is to analyze the difference between successive image data. It is difficult to detect moving objects in the images recorded from dynamic cameras attached to moving platforms such as UAVs flying at low altitudes over a variety of terrain, since the acquired images have two motion components: 'camera motion' and 'object motion'. Therefore, the motion of independent objects can be obtained after the camera motion is compensated thoroughly via proper manipulations. In this study, the camera motion effects are removed by using wiener filter-based image registration, one of the non-parametric methods. In addition, an image pyramid structure is adopted to reduce the computational complexity for UAVs. We demonstrate the effectiveness of our method with experimental results on outdoor video sequences.

• 한국항공우주학회지
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• 제39권11호
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• pp.1013-1020
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• 2011

본 논문에서는 이동 목표물을 추적하기 위하여, 다수 무인항공기의 측정치를 이용한 목표물의 위치와 속도 추정기법을 제안하였다. 항공기와 목표물 사이의 상대거리와 시선각 정보를 이용하여 목표물의 위치, 속도 성분을 추정하는 확장필터를 구성하였다. 다수의 항공기 간 정보교환과 계산이 용이하도록 공분산 역행렬 형태의 정보필터를 설계하였다. 개별 확장필터, 부분 분산형 확장필터, 분산형 확장필터를 이용한 수치 시뮬레이션을 수행하여, 제안된 분산형 확장필터의 이동 목표물 추정 및 추적 성능을 검증하였다.

• 제어로봇시스템학회논문지
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• 제19권2호
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• pp.158-163
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• 2013

The fusion of the GPS (Global Positioning System) and DR (Dead Reckoning) is widely used for position and latitude estimation of vehicles such as a mobile robot, aerial vehicle and marine vehicle. Among the many types of aerial vehicles, grater focus is given on the quad-rotor and accuracy of the position information is becoming more important. In order to exactly estimate the position information, we propose the fusion method of GPS and Gyroscope sensor using the DEKF (Dual Extended Kalman Filter). The DEKF has an advantage of simultaneously estimating state value and a parameter of dynamical system. It can also be used even if state value is not available. In order to analyze the performance of DEKF, the computer simulation for estimating the position, the velocity and the angle in a circle trajectory of quad-rotor was done. As it can be seen from the simulation results using own proposed DEKF instead of EKF on own fusion method in the navigation of a quad-rotor gave better performance values.

• 한국군사과학기술학회지
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• 제23권5호
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• pp.466-474
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• 2020

Semi-active laser missile systems with high accuracy are necessary to asymmetric threats, such as UAV(Unmanned Aerial Vehicle). They are usually used to attack stationary or slow moving targets, therefore we should study on the laser designator which can detect and track fast moving targets in order to deal with UAV. In this study, design specifications are came up through performance analysis of existing laser designators, and laser designation method for fast moving target is developed. The detection and tracking performance of developed laser designator are verified through inside/outside tests on ground/aerial stationary/moving targets. Through this study, we obtain laser designator techniques that could be applied to actual semi-active laser missile systems.

• Natural Product Sciences
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• 제9권4호
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• pp.299-303
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• 2003

For the screening of inhibitors of sterol biosynthesis from natural products, a simple and rapid assay method was developed using recombinant yeast carrying human lanosterol synthase, main target of this assay method. Sterol biosynthesis inhibition activity was monitored only by the inhibition of growth of the recombinant yeast. By changing the substrate, this assay method can figure out which step is inhibited in the sterol biosynthesis by the test material. With this assay method total 102 plant samples were screened for their inhibitory activity of sterol biosynthesis. Among plant water extracts screened, 11 plant samples showed inhibitory activity on sterol biosynthesis in ergosterol (-) medium. For selection of the specific inhibitory materials, 11 plant samples were reassayed in ergosterol (+) medium. After all 5 plant samples, Abutilon avicennae Gaertn. (stem), Alnus japonica Steud. (stem), Amaranthus mangostanus L. (aerial part), Philadelphus schrenckii Pupr. (leaf) and Pimpinelia brachycarpa Nakai (aerial part), showed specific inhibitory activity.

• 제어로봇시스템학회논문지
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• 제16권2호
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• pp.101-106
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• 2010

Researches on air-ground robot cooperating system has been made recently. The cooperation among homogeneous robots focused on the architecture of the system, quality and influence of the communication. In contrast, the cooperation among heterogeneous robots such as aerial vehicle and ground vehicle robots has not been much handled. There are a couple of main points for those air-ground cooperating robots. One is using UAV (Unmanned Aerial Vehicle) as an extra sensor of UGV (Unmanned Ground Vehicle). This kind of application is usually used in situations such as guiding UGV to an appropriate path which could be better determined from the eye in the sky as UAV. The other main application of air-ground cooperating robot system is the localization. By combining sensor information from both UAV and UGV, the robot system as a whole can localize a target object or find features in the environment with better performance than UGV or UAV alone. Although these applications are recently studied in many different ways and devices, there are still a lot of possibilities in the field of air-ground cooperating robot systems. We introduce those research fields in this paper.

• 한국산업융합학회 논문집
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• 제23권2_1호
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• pp.125-137
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• 2020

Tracking micro-sized insects is one of the challenges of protecting ecosystems and biodiversity. In this study, we propose an approach for the autonomous tracking of micro-sized flying insects, and develop an unmanned aerial vehicle (UAV)-based robotic system. The Kalman filter is applied to the received signal strength emitted from radio telemetry to estimate the position while reducing the measurement error and noise. The autonomous tracking strategy is a method in which the UAV rotates at one point to measure the signal strength and control its position in the strongest direction of the signal. We also design a system architecture comprising a tracking sensor system and a UAV system for micro-sized insects. The estimation and autonomous tracking of the target position by the proposed system are verified and evaluated through dynamic simulation. Therefore, in this study, we propose and validate a UAV-based tracking system for micro-sized flying insects, which has not been proposed in studies conducted thus far.

• 한국항공우주학회지
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• 제47권4호
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• pp.266-273
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• 2019

다수의 소형 정찰용 무인항공기를 이용하여 탐색 및 정찰 임무를 수행하는데 있어서 무인항공기의 운용 대수, 비행고도 등 운용 조건에 따라 임무 수행의 효율성과 효과성은 크게 변경될 수 있다. 하지만 어떤 운용조건이 가장 합리적인지 판단하기는 쉽지 않다. 따라서 본 연구에서는 자율비행에 따라 충돌을 회피하면서 표적을 탐지 및 판별할 수 있는 무인항공기 비행 시뮬레이션을 개발하여 다수의 무인항공기 운용 시 보다 효과적이고 효율적인 운용조건을 도출할 수 있는 방안을 제시하였다.

• 한국환경복원기술학회지
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• 제24권6호
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• pp.89-96
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• 2021

In this study, a deep-learning image analysis model was established and validated for AI-based monitoring of the tidal flat ecosystem for marine protected creatures Ocypode stimpsoni and their habitat. The data in the study was constructed using an unmanned aerial vehicle, and the U-net model was applied for the deep learning model. The accuracy of deep learning model learning results was about 0.76 and about 0.8 each for the Ocypode stimpsoni and their burrow whose accuracy was higher. Analyzing the distribution of crabs and burrows by putting orthomosaic images of the entire study area to the learned deep learning model, it was confirmed that 1,943 Ocypode stimpsoni and 2,807 burrow were distributed in the study area. Through this study, the possibility of using the deep learning image analysis technology for monitoring the tidal ecosystem was confirmed. And it is expected that it can be used in the tidal ecosystem monitoring field by expanding the monitoring sites and target species in the future.