• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.6
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• pp.548-554
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• 2012

Verification and validation of operational software of the flight control computer, which is flight safety critical, is very important to prove correctness and faultness of the software. To verify the real-time softare requirement on operational software of flight control computer, real-time software internal parameter and variable monitoring technics on hardware-in-the-loop environment, similar to on-flight environment, is required. This paper describes flight safety critical software validation and verificiation environment using standard debugging interface, NEXUS 5001.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.11
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• pp.1130-1137
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• 2006

Relaxed Static Stability(RSS) concept has been applied to improve aerodynamic performance of modern version supersonic jet fighter aircraft. Therefore, the flight control systems are necessary to stabilizes the unstable aircraft and provides adequate handling qualities. The initial production flight control system are verified by flight test and it's always an elements of danger because of flight-critical nature of control law function and design error due to model base design method. These critical issues impact to flight safety, and it could be lead to a loss of aircraft and pilot's life. Therefore, development of an easily modifiable RFCS(Research Flight Control System) capable of reverting to a PFCS(Primary Flight Control System) of reliable control law must be developed to guarantee the flight safety. This paper addresses the concept of SSWM(Software Switching Mechanism) using the fader logic such as TFS(Transient Free Switch) based on T-50 flight control law. The result of the analysis based on non-real time simulation in-house software using SSWM reveals that the flight control system are switching between two computers without any problem.

• Journal of IKEEE
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• v.16 no.2
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• pp.145-152
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• 2012

This paper is the Software Hazard Analysis (SWHA) which will study the managerial process and the technical methode and techniques inherent in the performance of software safety task within the Military Aircraft System Safety program. This SWHA identifies potential hazardous effects on the software intensive systems and provides a comprehensive and qualitative assessment of the software safety. The purpose of this paper is to identify safety critical functions of software in Military A/C. The identified software hazards associated with the design or function will be evaluated for risks and operational constraint to further improve the software design requirement, analysis and testing efforts for safety critical software. This common SWHA, the first time analysis in KOREA, was review all avionics OFP(Operational Flight Program), and focus only on software segments which are safety critical. This paper provides a important understanding between the customer and developer as to how the software safety for the Military A/C will be accomplished. It will also provide the current best solution which may as one consider the necessary step in establishing a credible and cost-effective software safety program.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.84-87
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• 2008

ATTOL is a software unit testing tool produced by the ATTOL Testware SA in France. It automates the entire software unit testing process: test plan template and test program generation, test program execution, test result analysis and test report generation. ATTOL is suited for the development of embedded software as it allows programmers to operate in native and cross development environments. Particularly, it is used for the development of the flight software which is embedded in the Communication Ocean Meteorological Satellite (COMS). As the flight software is mission-critical, it requires the strict software quality and high testing constraints. The flight software of COMS is verified by ATTOL in native and cross platforms. In 2002, ATTOL was taken over by the IDM Rational Software and has been supplied with the name of Test RealTime (TestRT). The test process of TestRT becomes different from that of ATTOL as TestRT provides the new functionalities that were absent from ATTOL. TestRT provides the new features in the test script language, as well. In this paper, we compare the test process of ATTOL to TestRT With an example of COMS and explain what has been changed in the test script language.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.6
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• pp.557-565
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• 2004

The Korean space program was marked by the successful launching of a KSR-III liquid propelled sounding rocket. The Inertial Navigation System (INS) which carries out critical mission functions of navigation, guidance and control was domestically developed and perfectly certified through the flight test. The system consists of a strapdown inertial measurement, an onboard computer and flight software. This paper will describes the development works of the inertial navigation system, including top level system design, hardware and software. And it summarizes flight results.

• Journal of Astronomy and Space Sciences
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• v.39 no.4
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• pp.181-194
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• 2022

Korea Pathfinder Lunar Orbiter (KPLO), also known as Danuri, was successfully launched on 4 Aug. from Cape Canaveral Space Force Station using a Space-X Falcon-9 rocket. Flight dynamics (FD) operational readiness was one of the critical parts to be checked before the flight. To demonstrate FD software's readiness and enhance the operator's contingency response capabilities, KPLO FD specialists planned, organized, and conducted four simulations and two rehearsals before the KPLO launch. For the efficiency and integrity of FD simulation and rehearsal, different sets of blind test data were prepared, including the simulated tracking measurements that incorporated dynamical model errors, maneuver execution errors, and other errors associated with a tracking system. This paper presents the simulation and rehearsal results with lessons learned for the KPLO FD operational readiness checkout. As a result, every functionality of FD operation systems is firmly secured based on the operation procedure with an enhancement of contingency operational response capability. After conducting several simulations and rehearsals, KPLO FD specialists were much more confident in the flight teams' ability to overcome the challenges in a realistic flight and FD software's reliability in flying the KPLO. Moreover, the results of this work will provide numerous insights to the FD experts willing to prepare deep space flight operations.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.76-79
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• 2011

천리안 위성은 우리나라 최초의 정지궤도 복합 지구관측 위성으로 기상관측, 해양관측과 통신서비스 임무를 수행하는 중대형위성으로 2011년 6월 27일에 성공적으로 발사되어 약 6개월간의 시험운영기간을 거쳐 현재는 실시간 서비스를 제공하고 있다. 천리안 위성은 한국항공우주연구원(KARI) 총괄 주관하에 2003년 9월 개발을 시작으로 프랑스의 EADS-Astrium과 공동 개발되었다. 천리안 위성은 이미 EADS-Astrium에 의해 통신 위성 본체 플랫폼으로 우주 인증된 Eurostar3000(이하 E3000) 플랫폼을 근간으로 제작되었다. 본 논문에서는 천리안 위성 플랫폼 탑재컴퓨터에 탑재되어 위성체 전반을 운영하는 비행소프트웨어의 구성 및 기능에 대해 기술한다. 또한 기존의 EADS-Astrium사의 E3000 비행소프트웨어 생산라인을 바탕으로 천리안 위성 비행소프트웨어를 개발하기 위한 개발 절차 형상을 소개한다. 본 논문에서 기술한 재생산을 위한 개발 절차에 대한 접근 방법은 위성 임베디드 소프트웨어 시스템과 같은 mission critical 시스템이면서 이미 검증된 소프트웨어를 재사용하고 사용자의 요구사항을 만족시키기 위해 일부 기능을 변경 및 추가 개발하여 통합된 소프트웨어를 생산해야하는 소프트웨어 개발체계의 실질적인 한 예를 보여주고 있다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.5
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• pp.349-357
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• 2022

Since the flight control computer of unmanned aerial vehicle (UAV) is a flight critical equipment, it is necessary to ensure reliability and safety from the development step, and a redundancy-based fault management design is required in order to operate normally even a failure occurs. To reduce cost, weight and power consumption, the dual-redundant flight control system design is considered in UAV. However, there are various restrictions on the fault management design. In this paper, we propose the fault detection and isolation designs for the dual-redundant flight control computer to satisfy the safety requirements of an UAV. In addition, the flight control computer developed by applying the fault management design performed functional tests in the integrated test environment, and after performing FMET in the HILS, its reliability was verified through flight tests.

• Journal of Aerospace System Engineering
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• v.13 no.1
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• pp.62-68
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• 2019

The software installed on an aircraft is directly related to its safety. Therefore, it shall comply with the standards of the airworthiness certification to ensure safety of flight. Airborne software should be developed in accordance with the DO-178 (Software Consideration in Airborne Systems and Equipment Certification) to comply with the airworthiness certification criterion. However, the military airborne software has been developed in accordance with the DAPA weapons system software development and management manual. In this paper, we completed a questionnaire survey of software experts. We also suggest a military airborne software development/certification process based on DO-178.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.8
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• pp.657-664
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• 2013

The flight loads analysis was carried out on the aircraft with high aspect ratio flexible wings by using commercial software MSC/NASTRAN. The aerodynamic model for flight loads analysis was corrected, compared with results of the wind tunnel test. And in-house program was developed for pre and post works. In-house program enabling management of much data automatically consists of three modules: 'Construction of the mass distributed model', 'Selection of critical load cases', 'Generation of external loads for structural design'. By utilizing these techniques and programs, the procedure of flight loads analysis was established for effective development of an aircraft.