• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.3
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• pp.14-20
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• 2018

An estimation law of air mass flow rate for high speed engine control is presented. The variables of mass estimation equations are modified to measurable variables which can be obtained during flight, and the effectiveness of each variable to the estimation accuracy is evaluated. The equation is modified to a simplified form, and the uncertainty is evaluated. In addition, reference data for the selection of estimation methods is suggested by considering the sensitivity analysis of sensor error.

• Communications of the Korean Institute of Information Scientists and Engineers
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• v.31 no.11
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• pp.15-21
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• 2013

• Bulletin of the Korean Space Science Society
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• 2007.10a
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• pp.52-52
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• 2007

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.12
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• pp.1217-1222
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• 2010

This paper describes the Model-Based Development(MBD) process behind the flight control software of a close-range unmanned aerial vehicle(KUS-9). An integrated development environment was created using a commercial tool(MATLAB $Simulink^{(R)}$), which was utilized to design models for linear/nonlinear simulation, flight control law, operational logic and HILS(Hardware In the Loop Simulation) system. Software requirements were validated through flight simulations and peer reviews during the design process, whereas the models were verified through the application of a DO-178B verification tool. The integrity of automatically generated C code was verified by using a separate S/W testing tool. The finished software product was embedded on two different types of hardware and real-time operating system(uC/OS-II, VxWorks) to perform HILS and flight tests. The key findings of this study are that MBD Technology enables the development of a reusable and an extensible software product and auto-code generation technology allows the production of a highly reliable flight control software under a compressed time schedule.

• Annual Conference of KIPS
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• 2013.05a
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• pp.219-222
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• 2013

최근 몇 년간 무인항공기(UAV) 시장이 점차 커지면서 군뿐만 아니라 민간, 상업적으로도 무인항공기의 수요가 증가하고 있다. 이에 무인항공기의 한 종류인 에어드론(AR.Drone)을 활용한 실시간 원격 쿼드로터(Quadrotor) 퓨전제어기법을 제안하였다. 특히, 본 논문에서는 아이폰(i-phone) 기반의 제어기법이 아닌, 안드로이드(Android) 기반의 퓨전제어기법을 통하여 에어드론을 실시간으로 원격조정가능하게 했는데, 이는 아이폰 App 개발 시 제공되는 API와 PC 기반의 쿼드로터 제어기법을 퓨전하는 방식으로 쿼드로터의 비행제어와 영상처리를 분리시켜 기존의 방식보다 영상처리 속도를 향상시키는 방식이다. 그리고 제안된 퓨전제어기법의 우수성을 보여주기 위해, 기존의 방식들과 영상처리 속도를 비교분석하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.5
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• pp.416-422
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• 2016

This paper presents preliminary performance analysis of a satellite formation flying testbed, which is under development by Astrodynamics and Control Laboratory, Department of Astronomy, Yonsei University. A model reference adaptive controller (MRAC) with a first-order reference model is chosen to enhance the response of reaction wheel system which is subject to uncertainties caused by unmodelled dynamics and measurement noise. In addition, an on-line parameter estimation (OPE) technique based on the least square is combined to eliminate the effect of angular measurement noise by estimating the moment of inertia. Both numerical simulations and hardware experiments with MRAC support the effectiveness and applicability of the adaptive control scheme, which maintains the tracking error below $0.25^{\circ}$ for the entire time span. However, the high frequency control input generated in hardware experiment strongly suggests design modifications to reduce the effect of deadzone.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.7
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• pp.600-609
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• 2017

We designed a target management integration system that enables us to select the final target manually or automatically from seeker's sensor image. The integrated system was developed separately for the air vehicle system and the ground system. The air vehicle system simulates the motion dynamics and the sensor image of the air vehicle, and the ground system is composed of the target template image module and the ground control center module. The flight maneuver of the air vehicle is based on pseudo 6-degree of freedom motion equation and the proportional navigation guidance. The sensor image module was developed using the known infrared(IR) image rendering method, and was verified by comparing the rendered image to that of a commercial software. The ground control center module includes an user interface that can display as much information to meet user needs. Finally, we verified the integrated system with simulated impact target mission of the air vehicle, by confirming the final target change and the shot down result of the user's intervention.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.5
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• pp.373-381
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• 2020

Quadrotor is simple to model because of the symmetric structure but it has the disadvantage of being relatively sensitive to the external disturbance and system uncertainty. The PID technique applied for the attitude control of quadrotor has been applied comprehensively, but it has a disadvantage that is hard to precise control in the nonlinear system. In this work, a quadrotor attitude control law using the super twisting algorithm is studied, which has robust characteristics against disturbance and system uncertainty. To evaluate the attitude performance by the proposed technique, simulation studies and actual flight tests are carried out, and compared with the conventional PID controller.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.7
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• pp.479-487
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• 2022

This paper presents the control and guidance algorithm of a KAU-SPUAV(Korea Aerospace University - Solar Powered Unmanned Aerial Vehicle) which is designed and developed in Korea Aerospace University. Aerodynamic coefficients are calculated using the vortex-lattice method and applied to the aircraft's six degrees of freedom equation. In addition, the thrust and torque coefficients of the propeller are calculated using the blade element theory. An altitude controller using thrust was used for longitudinal control of KAU-SPUAV to glide efficiently when it comes across the upwind. Also describes wind estimation technic for considering wind effect during flight. Finally, introduce some guidance laws for endurance, mission and coping with strong headwinds and autonomous landing.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.99-100
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• 2016

드론이나 이동형 촬영장비에 장착된 카메라로부터 깨끗하고 안정된 영상을 획득하기 위해서는 짐벌시스템의 안정화기 설계가 필요하다. 짐벌시스템은 카메라 모듈을 지지하는 구조와 외부로 부터의 진동을 차단하면서 정확한 각도를 추종하는 안정화기로 구성된다. 이동형 촬영장비나, 비행중인 드론에는 매우 다양한 주파수 성분의 진동이 발생되는데, 이러한 진동을 제어하기 위하여 6자유도 운동방정식을 유도하고, 이 중에서 본 논문에서는 일반적으로 rolling, pitching, yawing 운동에 대해서는 PID 제어기를 사용하여 안정화를 제어하기만, 카메라종류나 짐벌시스템 구조가 바뀔 때 마다 PID 파라미터를 변경해야 되는 경우가 빈번하다. 본 논문에서는 이런 문제점을 개선하기 새로이 제기된 제어 기법인 지적 PID(intelligent PID) 제어를 통하여 진동제어를 수행하여 짐벌시스템의 안정화를 위한 제어기법을 제안하고자 한다.