• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.6
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• pp.473-480
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• 2021

In this paper, We analyze and present improvements to problems in software quality through Static Analysis for Open Source, which is widely used as the Flight Controller software for small unmanned aerial vehicle drones. MISRA coding rules, which are widely applied based on software quality, have been selected. Static analysis tools were used by LDRA tools certified international tools used in all industries, including automobiles, railways, nuclear power and healthcare, as well as aviation. We have identified some safety-threatening problems across the quality of the software, such as structure of open source modules, analysis of usage data, compliance with coding rules, and quality indicators (complexity and testability), and have presented improvements.

• Proceedings of the ESK Conference
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• 1992.10a
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• pp.26-32
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• 1992

세계적으로 항공기 사고의 통계적 분석에 의하면 항공기 운용자의 인적과실(Human error)로 인한 항공기 사고가 약 70% 이상으로 보고되고 있다. 항공기 운용자의 인적과실에 기인한 요인들 중에서 운용자의 작업량, 작업공간, 작업환경, 인체크기, 인체 생리, 인간 심리 및 습관 등을 항공기 설계단계에서 고려하지 못한 요인이 대부분이다. 일반적으로 항공기 비행품질(Flying qualities)의 영향을 주는 설계분야는 크게 세가지로 항공기 형상(Configuration), 조종체계(Control system)및 조종실 배치(Cockpit layout)로 분류된다. 이들 세가지 설계분야 중에서 조종실의 운용자 인간공학적인 요구 사항을 고려하지 않으면 항공기 운용성 품질중에서 삼분의 일이 감소될 수 있다. 그리고 항공기 개발시에 전담하는 항공기 설계 분야별로 구분하고 그 전담설계 부서들과 인간공학적 조종실 설계 전담 부서가 항공기 비행 품질 및 운용자 인적과실(Human error)에 미치는 영향을 분석하고 인간공학의 중요성을 강조한다. 항공기를 개발할때에 개발자는 그 항공기를 운용하는 운용자의 인체, 생리, 심리, 습관 등을 고려 하여 항공기 조종실의 인간공학적 최적화 설계 및 배치 (Design and layout)를 개발초기단계부터 항공기를 설계할때에, 그 항공기의 조종실 품질은 조종사가 항공기 비행 임무를 수행할때에 항공기 비행을 위한 용이한 정보 인식(Sencing), 용이한 정보 결심(Deciding) 및 용이한 조종(Manipulating)의 특성을 조종사에게 제공할 때 항공기 비행 품질이 좋아질 것이다.

• Aerospace Engineering and Technology
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• v.7 no.2
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• pp.123-130
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• 2008

Flight safety analysis, which includes risk estimation for the various abnormal flight modes in addition to normal flight, has to be performed necessarily to guarantee launch safety for the operation of space launch vehicles. For this purpose, a dedicated system has been developed such that all the necessary repetitive computations, result reports, and graphical presentations can be performed inside a single system for user convenience. In addition, the developed system is capable of representing computed results on a three dimensional Earth for the realistic presentation. The developed Flight Safety Analysis System will be employed for the launch operation of Korea Satellite Launch Vehicle-I.

• Current Industrial and Technological Trends in Aerospace
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• v.6 no.2
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• pp.143-153
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• 2008

This paper describes the current research trend and future development direction of autonomous flight of the aircraft. The autonomous flight means that aircraft control system recognize and cope with the emergency situation confronted during the flight by itself. Current research for autonomous flight technology is mainly performed for the application to unmanned air vehicle. Considering advent of future air traffic management system and increasing demand of the unmanned air vehicle application, however, autonomous flight technology required to be combined with future air traffic management system. In this paper, the current air traffic management system and anticipating change in future air traffic management system was investigated and research activities of autonomous flight technology was described as well as future prospect.

• Journal of Advanced Navigation Technology
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• v.21 no.1
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• pp.58-65
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• 2017

Global navigation satellite system (GNSS) has a weakness of signal integrity caused by broadcasting type data transmitting direct to user from navigation satellite. Loss of GNSS signal integrity can make a catastrophic event in the operation of unmanned aerial system (UAS) because position decision is only depended on GNSS. So it is required to apply alternative method to reduce a risk and to guarantee a GNSS signal integrity for UAS operation. This paper addressed the reason of loosing GNSS signal integrity, the effectiveness of signal jamming/spoofing and GNSS application trend for UAS. Also suggested the flight safety enhancing method in case of GNSS signal jamming for UAS as technical and political approaches.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.9
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• pp.781-789
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• 2021

In this paper, we quantitatively analyzed the required UAV(Unmanned Aerial Vehicle) failure rate of small UAV (≤25kg) based on the harm to human caused by UAV crash to fly over the populated area. We compute the number of harm to human when UAV falls to the ground at certain descent point by using population density, car traffic, building to land ratio, number of floors of building data of urban area and UAV descent trajectory modeling. Based on this, the maximum allowable UAV failure rate is calculated to satisfy the Target Level of Safety(TLS) for each UAV descent point. Then we can generate the failure rate requirement in the form of map. Finally, we divide UAV failure rate into few categories and analyze the possible flight area for each failure rate categories. Considering the Youngwol area, it is analyzed that the UAV failure rate of at least 10^-4 (failure/flight hour) is required to access the residential area.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.1
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• pp.47-59
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• 2014

This paper deals with a vision-based trajectory tracking control system for a quadrotor-type UAV for entertainment purpose in indoor environment. In contrast to outdoor flights that emphasize the autonomy to complete special missions such as aerial photographs and reconnaissance, indoor flights for entertainment require trajectory following and hovering skills especially in precision and stability of performance. This paper proposes a trajectory tracking control system consisting of a motion generation module, a pose estimation module, and a trajectory tracking module. The motion generation module generates a sequence of motions that are specified by 3-D locations at each sampling time. In the pose estimation module, 3-D position and orientation information of a quadrotor is estimated by recognizing a circular ring pattern installed on the vehicle. The trajectory tracking module controls the 3-D position of a quadrotor in real time using the information from the motion generation module and pose estimation module. The proposed system is tested through several experiments in view of one-point, multi-points, and trajectory tracking control.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.6
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• pp.517-525
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• 2007

As usage of UAV becomes more common, a basic requirements on the system are changing. Existent system did function embodiment by major object, but current UAV puts bigger weight to availability. Therefore, all the advanced countries in UAV technologies put great efforts in reliability analysis techniques and source collection of system, and reflect the result in design. The authors are developing a flight control system for a UAV and using the reliability analysis techniques in the process. This paper introduces basic reliability analysis techniques and results of analysis for a small UAV flight control system that is developing present. The result plans efficiency enlargement UAV development and operation process.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.8
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• pp.673-679
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• 2013

Photogrammetric techniques were used to analyze separation characteristics of store in safe separation flight test. In this analysis, we used single camera method to analyze 6 degrees of freedom of separated store. We established instrumentation requirements based on theoretical background of photogrammetry and guidelines of MIL-HDBK-1763. We applied the photogrammetry to flight test and extracted separation trajectory. We empirically estimated the input variables uncertainties of photogrammetry and its effects on separation trajectory. Using this trajectory which includes the photogrammetric error, we analyzed the safety of separation.

• Journal of Advanced Navigation Technology
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• v.21 no.6
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• pp.579-584
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• 2017

SBAS is a satellite based navigation correction system that provides correction information and integrity information of GNSS signal through geostationary satellite based on analysis of GNSS signal in ground station. KASS, a Korean SBAS, is aiming at the APV-1 class SoL service in 2022. Sufficient ground and flight tests must be performed in advance to provide SoL services. However, since KASS, the Korean SBAS, has not yet been added in Korea, specific detailed evaluation items are not presented. EGNOS, which is expected to be the most compatible with KASS and is being serviced after its development, has already been evaluated. In this paper, we analyze the regulations applied to EGNOS construction and analyze the criteria of ground and flight test evaluation items required for flight testing, which is expected to be referenced to the flight inspection process in the future.