• 반도체디스플레이기술학회지
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• 제19권2호
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• pp.1-10
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• 2020

Blockchain enabled Decentralized Autonomous Organization (DAO), a new form of organization with conveying its core value - trust. Token holders who are participating DAO's governance share their thoughts, information, and ideas in online forum. But it is problem that chronological form of DAO's online forum makes token holders hard to find crucial information, meaning that many of them might not understand what is happening discussion. In this paper, we studied not only a decision making process which feature is iteration, visualization, and applicable to DAO with 6 steps in total but also a decision making tool which is based on the process of this paper. The tool has features to help participants such as voting model, visualization features which gives guidance to them for their decision during the process. Our experiment showed that the process and tool is somewhat reasonable, and the information during the process is effective for participants. This work is expected to be applied to current DAOs to make a decision among the token holders.

• 한국지리정보학회지
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• 제26권1호
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• pp.1-10
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• 2023

4차 산업혁명 시대의 도래에 따라 자율주행 기술에 관한 관심이 증대되고 있다. 이에 따라 기존 교통시설에 대한 자율주행차의 적용 가능성 및 정밀도로지도의 활용과 함께 자율주행차에 부착된 센서를 이용하여 주변 상황을 인지함으로써 안전한 주행을 모색해야 할 필요가 있다. 본 연구에서는 자율주행시대에 도로· 교통 인프라 개선을 위해 개발한 자율주행차에 장착된 센서를 통해 인지하는 표지 시설의 활용을 위해 기존 도로시설물인 도로표지, 교통안전표지, 시선유도시설과 정밀도로지도의 시설물 관련 레이어와의 비교분석을 통한 자율주행차량이 인식 가능한 표지 시설의 역할을 도출한다. 자율주행차량이 인식 가능한 표지 시설은 자율주행차에 직접 특정한 행동을 수행하도록 하는 등의 역할을 함으로써 안전주행을 도모할 수 있다. 자율주행차가 센서를 이용하여 표지시설을 인지함으로써 주행안전을 도모하기 위해서는 설치와 관리 및 활용 기준의 마련이 필요하며, 기준에 따라 지속해서 관리 및 감독이 이루어져야 할 것으로 사료된다.

• 제어로봇시스템학회논문지
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• 제11권3호
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• pp.207-213
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• 2005

This paper deals with an autonomous flight guidance and control algorithm design for TR301 tilt-rotor airplane under development by Korea Aerospace Research Institute for simulation purpose. The objective of this study is to design autonomous flight algorithm in which the tilt-rotor airplane should follow the given waypoints precisely. The approach to this objective in this study is that, first of all, model-based inversion is applied to the highly nonlinear tilt-rotor dynamics, where the tilt-rotor airplane is assumed to fly at helicopter flight mode(nacelle angle=0 deg), and then the control algorithm, based on classical control, is designed to satisfy overall system stabilization and precise waypoint following performance. Especially, model uncertainties due to the tiltrotor model itself and inversion process are adaptively compensated in a simple neural network(Sigma-Phi NN) for performance robustness. The designed algorithm is evaluated in the tilt-rotor nonlinear airplane in helicopter flight mode to analyze the following performance for given waypoints. The simulation results show that the waypoint following responses for this algorithm are satisfactory, and control input responses are within control limits without saturation.

• 제어로봇시스템학회논문지
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• 제17권8호
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• pp.833-842
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• 2011

The objectives of this research are development of guidance, navigation and control system for RUAV on virtual instrumentation and real flight test. For this research, the system is divided to DAQ (data acquisition) section, actuator section and controller section. And the hardware and software on each sections are realized on LabVIEW base. Waypoint guidance and control of auto flight are realized using PID gain tuning and waypoint vector tracking guidance algorism. For safe flight test, auto/manual switching module isolated from FCS (Flight Control System) is developed. By using the switch module, swift mode change was achieved during emergency flight case. Consequently, a meter level error of flight performance is achieved.

• 한국해양공학회지
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• 제23권5호
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• pp.61-70
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• 2009

An AUV (Autonomous Underwater Vehicle) is an unmanned underwater vessel to investigate sea environments and deep sea resource. To be completely autonomous, AUV must have the ability to home and dock to the launcher. In this paper, we consider a class of homing trajectory planning problem for an AUV with kinematic and tactical constraints in horizontal plane. Since the AUV under consideration has underactuated characteristics, trajectory for this kind of AUV must be designed considering the underactuated characteristics. Otherwise, the AUV cannot follow the trajectory. Proposed homing trajectory panning method that called VGM (Virtual Goal Method) based on visibility graph takes the underactated characteristics into consideration. And it guarantees shortest collision free trajectory. For tracking control, we propose a PD controller by simple guidance law. Finally, we validate the trajectory planning algorithm and tracking controller by numerical simulation and ocean engineering basin experiment in KORDI.

• 한국지능시스템학회논문지
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• 제19권5호
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• pp.737-742
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• 2009

청소 로봇, 관광 안내 로봇부터 우주 탐사로봇까지 자율이동로봇의 응용분야가 넓어짐에 따라서 자율이동로봇의 인기는 급속도로 높아지고 있다. 하지만 동적인 환경 내에서 자율이동로봇의 안전한 네비게이션을 위한 만족스러운 제어 알고리즘은 여전히 연구 과제이다. 본 논문에서는 새로운 Potential field method를 이용한 제어 방법을 제안하였고, 컴퓨터 시뮬레이션을 통해 제안한 알고리즘을 실행하고 분석하였고, 이 실험 결과들로서 Potential field method를 사용한 행동(behavior)에 기반한 제어 시스템의 유효성을 나타내었다.

• 대한기계학회논문집A
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• 제38권5호
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• pp.551-557
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• 2014

본 논문은 작업 시 농업용 트랙터의 운전지원을 위한 강인한 횡방향 제어기를 제안하고자 한다. 자동차와 달리 트랙터의 조향 방식은 유압실린더를 이용함으로써 상대적으로 큰 시간지연을 가지고 있으며 작업 시 지면 환경도 일반 도로와는 다르다. 조향 액추에이터 모델을 포함하는 기구학적 트랙터 모델을 기반으로 동적 표면 제어라는 비선형 제어기법을 적용하여 조향 액추에이터의 시간지연 및 노면 경사의 변화에 강인한 횡방향 제어기를 설계한다. 마지막으로 상용 트랙터 시뮬레이터를 이용하여 마찰 계수가 일정한 주어진 노면 상태에서 조향 액추에이터의 시간 지연 변경이나 오르막 또는 내리막과 같은 지형 조건 변화에 대한 횡방향 제어기의 성능 및 강인성을 검증한다.

• 한국항공우주학회지
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• 제42권3호
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• pp.199-212
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• 2014

본 논문은 무인전투기를 위한 일대일 근접 교전 상황에서의 가상 추적점을 이용한 자율 공중 교전 법칙에 관해 기술하였다. 가상의 지연 및 선도 추적점으로 구성된 가상 추적점은 전술 교전 기동을 수행하기 위해서 도입한 것으로 각 가상 추적점은 전투기의 공력 특성과 기본 전투 기동의 선회원, 총 에너지 및 무기 거동 특성을 고려하여 생성된다. 무인전투기는 현재의 교전 상태를 기반으로 기동 전환을 위해 각 추적 기동의 확률을 평가하는 스무딩 함수를 이용해 단일의 가상 추적점을 결정하고 추적 기동을 실시하게 된다. 제안된 기법은 상용 전투기 모델과 X-Plane 시뮬레이터를 이용한 고충실도의 실시간 교전시뮬레이션을 통해 성능을 검증하였다.

• Journal of Biosystems Engineering
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• 제34권4호
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• pp.278-285
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• 2009

Navigation system is applied in variety of fields including the simple location positioning, autopilot navigation of unmanned robot tractor, autonomous guidance systems for agricultural vehicles, construction of large field works that require high precision and map making process. Particularly utilization of GPS (Global Positioning System) is very common in the present navigation system. This study introduces a navigation system for autonomous field robot that travels to the pre-input path using GPS information. Performance of the GPS- based navigation is highly depended on its receiving rate because GPS receivers do not acquire any navigation information in the period between the refresh intervals. So this study presents an algorithm that improves an accuracy of the navigation by estimation the positional information during the blind period of a low rate GPS receiver. In fact the algorithm calculated the robot's heading in a 50 Hz rate, so the blind period of an 1 Hz GPS receiver is extensively covered. Consequently implementation of the algorithm to the GPS based navigation showed an improvement in guidance accuracy. The conventional field robot directly carried an expensive control computer and sensors onboard, therefore the miniaturization and weight reduction of the robot was limited. In this paper, the field robot carried only communication equipments such as GPS module, normal RC receiver, and bluetooth modem. This enabled the field robot to be built in an economic cost and miniature size.

• Journal of Biosystems Engineering
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• 제37권5호
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• pp.287-295
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• 2012

Purpose: Some of the most representative approaches are to apply next generation technologies to save energy consumption, fully automated control system to appropriately maintain environmental conditions, and autonomous assistance system to reduce labor load and ensure operator's safety. Nevertheless, improvement of upcoming method for soil cultured greenhouse has not been sufficiently achieved. Geometrical complexity of ground in protected crop cultivation might be one of the most dominant factors in design of autonomous vehicle. While there is a practical solution fairly enough to promise an accurate travelling, such as autonomous sprayer guided by rail or induction coil, for various reasons including the limitation of producer's budget, the previously developed sprayer has not been widely distributed to market. Methods: In this study, we developed an autonomous sprayer considering travelling performance on geometrical complexity of ground in soil cultured greenhouse. To maintain a stable travelling and to acquire a real time feedback, common wire with 80 mm thick and body frame and sprayer boom. To evaluate performance of the prototype, tracking performance, climbing performance and spraying boom's uniform leveling performance were individually evaluated by corresponding experimental tests. Results: The autonomous guidance system was proved to be sufficiently suitable for accurate linear traveling with RMS as lower than approximately 10 cm from designated path. Also the prototype could climb $10^{\circ}$ of ground's slope angle with 40 kg of water weight. Uniform leveling of spraying boom was successfully performed within $0.5^{\circ}$ of sprayer boom's slope. Conclusions: Considering more complex pathways and coarse ground conditions, evaluations and improvements of the prototype should be performed for promising reliability to commercialization.