• International Journal of Aeronautical and Space Sciences
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• 제5권1호
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• pp.57-63
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• 2004

UAV(Unmanned Aerial Vehicle) has become one of the most popularmilitary/commercial aerial robots in the new millennium. In spite of all theadvantages that UAVs inherently have, it is not an easv job to develop a UAVbecause it requires very systematic and complete approaches in full developmentenvelop. The ground test and evaluation phase has the utmost importance in thesense that a well-developed system can be best verified on the ground. In addition,many of the aircraft crashes in the flight tests were resulted from the incompletedevelopment procedure. In this research, a verification procedure of the wholeairbome integrated system was conducted including the flight management system.An airbome flight control computer(FCC) senses the extemal environment from thepehpheral devices and sends the control signal to the actuating system using theassigned control logic and flight test strategy. A ground test station controls themission during the test while the downlink data are transferred from the flightmanagement computer using the serial communication interface. The pilot controlbox also applies additional manual actuating commands. The whole system wastested/verified on the wind-tunnel system, which gave a good pitch controlperformance with a preUspecified flight test procedure. The ground test systemguarantees the performance of fundamental functions of airbome electronic systemfor the future flight tests.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.554-557
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• 1993

The error analysis for the Time-in-Flight Laser Range Finder with Multiple Tone Amplitude Modulation relevant to the phase detection error is made. The distance can be estimated to solve the formulate which express the relationship between the absolute distance from the range finder to the object and the wavenumbers and the phases of the modulated waves by the optimization technique. The main cause of the estimation error can be considered as the phase detection error induced from the amplitude modulator and the phase detector. To clarify the phase detection error and the optimal amplitude frequency set, the numerical analysis are made.

• 정보통신설비학회논문지
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• 제4권1호
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• pp.1-6
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• 2005

As an application of the GPS/SDINS integration for its synergistic results, the alignments of the SDINS utilizing GPS carrier phase rate measurements is introduced. A measurement model of GPS carrier phase rate, which does not require integer ambiguity determination process, is newly derived in order to be adopted with the SDINS in-flight alignment process. For in-flight alignment, the performance of the GPS/SDINS integration method suggested in this paper is analyzed using the covariance analysis.

• Journal of Positioning, Navigation, and Timing
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• 제10권4호
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• pp.253-262
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• 2021

Global Navigation Satellite Systems (GNSS) based precise positioning using Real Time Kinematic (RTK) technique has been proposed as an enabler of the formation operation of moving vehicles. In RTK methods, the integer ambiguity of GNSS carrier phase measurements must be resolved. Although there have been many proposed algorithms for the integer ambiguity resolution, the widelane combination of carrier phase measurements and LAMBDA methods have gained the most popularity in literatures when dual frequency GNSS measurements were used. In this paper, we evaluated five alternative methods to determine relative positions of moving base and rover receivers; the round-off scheme of widelane carrier phase, instant least-squares and Kalman filter-based LAMBDA with widelane carrier phase, instant least-squares and Kalman filter-based LAMBDA with dual frequency measurements. The paper presented the performance of each method using flight test data, which showed their strength and weakness in the aspects of time-to-first-fix, ambiguity resolution success ratio, and relative position errors. Based on that, we provided practical recommendations of RTK operations for moving vehicles.

• Mass Spectrometry Letters
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• 제9권3호
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• pp.77-80
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• 2018

The focus of this paper is to present techniques to overcome certain difficulties in quantitative analysis with a time-of-flight mass spectrometer (TOF-MS). The method is based on conventional solid-phase extraction, followed by reversed-phase ultra high performance liquid chromatography of the extract, and mass spectrometric analysis. The target compounds included atenolol, atrazine, caffeine, carbamazepine, diclofenac, estrone, ibuprofen, naproxen, simazine, sucralose, sulfamethoxazole, and triclosan. The matrix effects caused by high concentrations of organic compounds in wastewater are especially significant in electrospray ionization mass spectroscopy. Internal-standard calibration with isotopically labeled standards corrects the results for many matrix effects, but some peculiarities were observed. The problems encountered in quantitation of carbamazepine and triclosan, due to nonlinear calibration were solved by changing the internal standard and using a narrower mass window. With simazine, the use of a quadratic calibration curve was the best solution.

• International Journal of Aeronautical and Space Sciences
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• 제9권1호
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• pp.31-41
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• 2008

This paper deals with the energy saving problem of the follower aircraft in the loose leader-follower formation geometry in which the lateral separation between formation members is more than a wingspan of the leader aircraft. This formation geometry offers no drag benefit, but has a strategic advantage. In the case of loose formation flight, the follower aircraft usually consumes more energy than the leader aircraft because the follower aircraft should use more thrust to maintain given formation geometry, especially during the turning phase from the outside of the leader"s flight path or join-up phase. A formation control scheme based on the energy maneuverability is proposed in this paper. To design the proposed control law, the velocity command is designed using feedback linearization for the horizontal formation geometry and then coverts it to the altitude command using the energy equation. Numerical simulation is performed to verify the effectiveness of the proposed controller.

• 항공우주시스템공학회지
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• 제8권2호
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• pp.27-32
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• 2014

From the flight safety and the performance point of views, a new engine installation impacts an helicopter development or upgrade program significantly. More than a close relationship between an aircraft manufacturer and an engine manufacturer is necessary for the best integration work from the program initiation phase. In this paper, technical cooperation between aircraft and engine companies, and technical supports by the engine manufacturer for the T700/701K engine during the Surion development program are summarized. The applications of official technical program documents, US Mil-spec, France airworthiness regulations as the standard of the engine installation work, and engineering activities at each phase such as contract, design and manufacturing, flight clearance, ground and flight tests are described. This paper would be a cornerstone for the future domestic helicopter development program.

• 한국항공우주학회지
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• 제39권1호
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• pp.33-41
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• 2011

내삽형 부스터의 분리 운동 수학모델을 소개하였다. 부스터 분리 운동을 시뮬레이션 하기 위하여 3자유도 2물체 운동모델을 정립하였다. 유도탄과 공기중에 노출되는 부스터 영역의 공력모델을 개발하였다. 그리고, 부스터를 밀어내는 가스발생기도 모델링하였다. 이 모델을 시뮬레이션하기 위하여 유도탄이 부스터 분리과정에서 계속 1g 수평비행 조건을 유지한다는 가정을 세우고, 이를 기반으로 유도탄과 부스터간의 작용력을 분리 단계별로 정의 할 수 있었다. 단계 0: 초기, 단계 1: 선형이동, 단계 2: 자유운동. 이 시뮬레이션을 통하여 부스터를 안전하게 분리할 수 있는 유도탄의 마하수 및 고도의 범위를 제안할 수 있었다.

• Journal of Positioning, Navigation, and Timing
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• 제2권1호
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• pp.41-48
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• 2013

When the ground subsystem of Ground Based Augmentation System(GBAS) is installed at the airport, the functions and performance of subsystem should be evaluated through ground and flight testing at the pre-commissioning phase. In the case of GBAS flight testing, it can be conducted by the existing flight check aircraft, but the GBAS ground testing requires the development of specially customized equipment to perform the ground testing. Therefore, this paper describes the preliminary design of GBAS onboard test equipment which can be independently used for the GBAS ground testing and flight testing on a car and an aircraft.

• 제어로봇시스템학회논문지
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• 제11권11호
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• pp.963-969
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• 2005

An advanced method of Relaxed Static Stability (RSS) is utilized for improving the aerodynamic performance of modem version supersonic jet fighter aircraft. The flight control system utilizes RSS criteria in both longitudinal and lateral-directional axes to achieve performance enhancements and improve stability. The T-50 advanced trainer employs the RSS concept in order to improve the aerodynamic performance and the flight control law in order to guarantee aircraft stability, The T-50 longitudinal control laws employ the dynamic inversion and proportional-plus-integral control method. This paper details the design process of developing longitudinal control laws for the RSS aircraft, utilizing the requirement of MIL-F-8785C. In addition, This paper addresses the analysis of aircraft characteristics such as damping, natural frequency, gain and phase margin about state variables for longitudinal inner loop feedback design.