• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2345-2348
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• 2003

This paper deals with a problem of automatic landing guidance and control system design. The auto-landing control system for the longitudinal motion is designed in the classical PID controller. The controller gains are properly adapted to variation of the performance using fuzzy logic as a gain scheduler for the PID gains. This control logic is applied to the problem of the automatic landing control system design. From the numerical simulation using the 6DOF nonlinear model of the associated airplane, it is shown that the auto-landing maneuver is successfully achieved from the start of the flight conditions: 1500 ft altitude, 250 ft/sec airspeed and zero flight path angle.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.801-804
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• 2013

전화기의 자동 다이얼링 기능은 전화기에서 개별 전화번호를 자동 발신하여 비상시 긴급 전화 또는 홍보와 안내 등의 통신을 지원하는 기능이다. 본 논문에서는 국내외 자동 다이얼링 관련 규정을 비교 분석하고 이에 대한 제도적 정비방향에 대해서도 같이 논하기로 한다.

• 한국항해항만학회지
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• 제31권7호
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• pp.563-568
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• 2007

In this paper, an adaptive neural network controller and its application to automatic berthing control of ship is presented. The neural network controller is trained online using adaptive interaction technique without any teaching data and off-line training phase. Firstly, the neural networks used to control rudder and propeller during automatic berthing process are presented. Secondly, computer simulations of automatic ship berthing are carried out in Pusan bay to verify the proposed controller under the influence of wind disturbance and measurement noise. The results of simulation show good performance of the developed berthing control system.

• 한국지능시스템학회논문지
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• 제21권6호
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• pp.755-760
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• 2011

본 논문은 파티클 필터(particle filter)를 이용한 레이저 내비게이션(laser navigation)의 위치측정 성능 향상에 관한 연구이다. 레이저 내비게이션은 무선항법장치(wireless navigation system)로써 무인 자율주행 장치(automatic guided vehicle)의 위치측정 및 제어에 주로 사용되며, 이는 기존의 유선유도장치(wired guidance system)들에 비해 유지보수에 유연하면서도 완전한 자율주행이 가능하다. 하지만 무선항법장치인 레이저 내비게이션은 반응속도가 느리며 고속주행 혹은 회전주행 시에 위치 정밀도가 크게 떨어지게 된다. 본 논문에서는 이와 같은 문제점을 해결하기 위해, 비선형(non-linear)/비가우시안(non-gaussian)의 시스템에서도 강인한 특성을 지닌 파티클 필터를 이용하여 위치 정밀도를 향상시키는 방법을 제안한다. 제안한 방법의 성능을 검증하기 위해, 레이저 내비게이션과 엔코더, 자이로가 장착된 지게차 AGV(automatic guided vehicle)를 사용하였으며, 제안된 방법과 상용화된 레이저 내비게이션의 위치측정 결과를 비교하였다. 실험 결과, 제안된 방법이 상용화된 레이저 내비게이션의 위치 정밀도에 비해 약 66.5% 향상됨을 확인하였다.

• International Journal of Aeronautical and Space Sciences
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• 제6권2호
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• pp.64-75
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• 2005

The Stratospheric Airship Platform (SAP) has a capability of performing the autonomous and guidance flight to satisfy given missions. To be used as the High Altitude Platforms (HAPs), the capabilities of controlling platform's accurate position and keeping the station point are the most important features. Under this circumstances Autonomous Flight Control System (AFCS) is a critical system and plays a key role in achieving the given requirements and succeeding in missions. In this paper, the design and analysis results of the AFCS algorithms and controller are presented. The brief summary of the AFCS hardware structure is also explained. The autopilot controller and guidance logics were designed based on the linear dynamics of the unmanned airship platform and the full nonlinear dynamics was considered to evaluate and verify their performances.

• 전기학회논문지
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• 제63권4호
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• pp.526-533
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• 2014

In this study, we introduce design methodology to develop a guidance for issuing heavy rainfall warning by using both RBFNNs(Radial basis function neural networks) and SVR(Support vector regression) model, and then carry out the comparative studies between two pattern classifiers. Individual classifiers are designed as architecture realized with the aid of optimization and pre-processing algorithm. Because the predictive performance of the existing heavy rainfall forecast system is commonly affected from diverse processing techniques of meteorological data, under-sampling method as the pre-processing method of input data is used, and also data discretization and feature extraction method for SVR and FCM clustering and PSO method for RBFNNs are exploited respectively. The observed data, AWS(Automatic weather wtation), supplied from KMA(korea meteorological administration), is used for training and testing of the proposed classifiers. The proposed classifiers offer the related information to issue a heavy rain warning in advance before 1 to 3 hours by using the selected meteorological data and the cumulated precipitation amount accumulated for 1 to 12 hours from AWS data. For performance evaluation of each classifier, ETS(Equitable Threat Score) method is used as standard verification method for predictive ability. Through the comparative studies of two classifiers, neuro-fuzzy method is effectively used for improved performance and to show stable predictive result of guidance to issue heavy rainfall warning.

• 제어로봇시스템학회논문지
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• 제20권11호
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• pp.1103-1111
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• 2014

The results of control law design for a tilt-rotor unmanned aerial vehicle that has a nacelle mounted wing extension (WE) are presented in this paper. It consists of a control surface mixer, stability and control augmentation system (SCAS), hold mode for altitude / speed / heading, and a guidance mode for preprogram and point navigation which includes automatic take-off and landing. The conversion corridor and the control moments derivatives between the original tilt-rotor and its variant of the nacelle mounted WE were compared to show the effectiveness of the WE. The nacelle conversion of the original tilt-rotor starts when the airspeed is greater than 30 km/h but its WE variant starts at 0 km/h in order to reduce the drag caused by the high incidence angle of the WE. The stability margins of the inner loop are presented with the optimization approach. The outer loops for the hold mode are designed with trial and error methods with linear and nonlinear simulation. The main control parameter for altitude control of the helicopter mode is thrust command and it is transferred to the pitch attitude command in airplane mode. Otherwise, the control parameter for the speed of the helicopter mode is the pitch attitude command and it is transferred to the thrust command in airplane mode. Therefore the speed and altitude hold mode are coupled to each other and are engaged at the same time when an internal pilot engages any of the altitude or speed hold modes. The nonlinear simulation results of the guidance control for the preprogrammed mode and point navigation are also presented including automatic take-off and landing in order to prove the full control law.

• International Journal of Aeronautical and Space Sciences
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• 제17권1호
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• pp.120-131
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• 2016

The full results of troubleshooting process related to the flight control system of a tilt-rotor type UAV in the flight tests are described. Flight tests were conducted in helicopter, conversion, and airplane modes. The vehicle was flown using automatic functions, which include speed-hold, altitude-hold, heading-hold, guidance modes, as well as automatic take-off and landing. Many unexpected problems occurred during the envelope expansion tests which were mostly under those automatic functions. The anomalies in helicopter mode include vortex ring state (VRS), long delay in the automatic take-off, and the initial overshoot in the automatic landing. In contrast, the anomalies in conversion mode are untrimmed AOS oscillation and the calibration errors of the air data sensors. The problems of low damping in rotor speed and roll rate responses are found in airplane mode. Once all of the known problems had been solved, the vehicle in airplane mode gradually reached the maximum design speed of 440km/h at the operation altitude of 3km. This paper also presents a comprehensive detailing of the control systems of the tilt-rotor unmanned air vehicle (UAV).

• 한국지능시스템학회논문지
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• 제22권3호
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• pp.367-372
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• 2012

본 논문은 아날로그형 자기위치 장치(magnetic positioning system)의 개발과 퍼지 추론 시스템(FIS: fuzzy inference system)을 통한 정밀도 향상에 관한 것이다. 자기위치 장치는 무인운반차(AGV: automatic guided vehicle)의 자기-자이로 유도장치(magnet-gyro guidance system)에 사용되는 장치로, 바닥에 매설된 자석의 위치를 계측하는 장치이다. 기존의 판매되고 있는 자기-자이로 유도 장치는 외국에서 독점 판매되고 있어, 국내에서는 가격이 매우 비싸다. 또한, 자기위치 장치에 디지털 타입의 단극성 홀센서를 이용하기 때문에 위치측정 정밀도가 낮다. 이에, 본 논문에서는 자기위치 장치를 직접 개발하였고 퍼지 추론 시스템을 통해 자기위치 장치의 정밀도 향상시켰다. 실험은 직접 개발한 아날로그형 자기위치 장치를 이용하였으며, 기존의 위치측정 방법과 제안된 방법의 성능을 비교하였다. 실험 결과, 제안된 방법이 자기위치 장치의 정밀도를 향상시킴을 확인하였다.

• 한국공작기계학회논문집
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• 제17권1호
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• pp.150-157
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• 2008

Bellows are commonly used in piping systems to absorb expansion and contraction in order to reduce stress. Unlike most piping components, bellows consist of a thin-walled shell of revolution with a corrugated meridian, in order to provide the flexibility needed to absorb mechanical movements. It is a composite shell structure consisting of at least one toroidal shell, an annular plate or conical shell. It is difficult to analyze the behavior of bellows because of its complex geometry. Simplified formulas for variable mechanical behaviors of bellows are provided by a standard called EJMA. An automatic design software for bellows is programming by using VBA(Visual Basic for Application) based on EJMA. Bellows engineers can effectively make a decision for bellows geometries because this software provides graphically design results in its post-processor. Bellows design software is expected to give quite a good guidance to practical design. The characteristics of bellows are also investigated through the automatic design process in bellows design software.