유도무기 비행시험 시스템을 위한 모델 기반 운용절차의 설계 및 개선

박웅(Woong Park),이재천(Jae-Chon Lee) 한국산학기술학회 2019 한국산학기술학회논문지 Vol.20 No.4

비행시험 운용절차는 유도무기 비행시험 시스템 설계 및 구현을 위한 중요 산출물의 하나로서 비행시험 진행 단계별 임무계획, 수행방법, 안전대책 등을 포함한다. 유도무기체계 개발이 첨단화, 전략화 됨에 따라서 유도무기 비행시험은 점차 복잡화, 광역화 되고 있다. 이에 따라 시험안전을 확보하기 위해서는 비행시험 운용절차의 신뢰성 증대가 요구되었다. 특히, 새로운 개념의 비행시험 수행을 위해서 시험 전 불확실성을 예측하고 대비할 수 있도록 비행시험 운용절차 설계에서 M&S 기법의 적용을 통한 검증이 필요하게 되었다. 관련 연구로서 비행시험의 최적 프레임워크 개발 연구와 비행시험 프로세스 모델기반 개선 연구들이 발표되었지만, 상위 개념의 프로세스를 중심으로 한 결과로서 하위 수준의 비행시험 자원과 연동하는 비행시험 운용절차에 직접 적용하기에는 구체성이 부족하였다. 또한, 기존의 문서기반으로 구성된 비행시험 운용절차는 시험자원의 거동과 성능에 대한 분석능력의 한계로 시험자원의 중복과 누락, 직관적이지 않는 표현으로 운용자 간의 의사소통 저하, 그리고 다수의 비행시험에 적용하기 위한 확장성 부족 등의 문제가 발생하였다. 이를 개선하기 위해 본 논문에서는 모델기반 시스템공학(MBSE) 기법의 적용을 통한 유도무기 비행시험 운용절차의 설계 방법을 제안하였다. 구체적으로 이전의 비행시험 정보를 기반으로 비행시험 진행 단계와 수행방안을 정의한 후, 요구사항으로부터 시험자원의 임무수행을 SysML 모델 기반으로 구성한 템플릿으로 제공하였다. 또한 시뮬레이션 분석을 통해서 정상상황과 비상상황에 대한 최적의 수행절차를 도출하였으며, 사례 적용을 통해서 검증하였다. 본 연구를 통해서 시험자원의 거동과 성능에 대한 분석능력의 증대로 신뢰성이 향상되었고, 다수의 비행시험에 적용할 수 있는 확장성으로 효율성이 증대되었으며, 향후 개발 예정인 유도무기 비행시험에도 지속적으로 활용할 수 있다. The flight test operational procedure artifact includes mission planning, execution methods, and safety measures for each step of test progress. As the development of guided missiles has become more advanced and strategic, flight test has become increasingly complex and broadened. Therefore, increased reliability of the flight test operation procedures was required to ensure test safety. Particularly, the design of the flight test operational procedures required verification through M&S to predict and prepare for the uncertainty in a new test. The relevant studies have published the optimal framework development for flight tests and the model-based improvements of flight test processes, but they lacked the specificity to be applied directly to the flight test operational procedures. In addition, the flight test operational procedures, which consist of document bases, have caused problems such as limitations of analysis capabilities, insensitive expressions, and lack of scalability for the behavior and performance analysis of test resources. To improve these problems, this paper proposes how to design operational procedure of guided missile flight test system by applying MBSE(Model-based Systems Engineering). This research has improved reliability by increasing the ability to analyze the behavior and performance of test resources, and increased efficiency with the scalability applicable to multiple flight tests. That can be also used continuously for the guided missile flight tests that will be developed in the future.

항공기 비행특성 확인을 위한 다자유도 가상비행 및 자유비행 풍동실험 시스템 개발

이재인(Jaein Lee),조동현(Donghyun Cho),이영건(Younggun Lee),이예빈(Yebin Lee),김광수(Kwangsoo Kim),김종범(Jongbum Kim) 한국항공우주학회 2023 韓國航空宇宙學會誌 Vol.51 No.3

항공기 개발 과정에서 비행제어시스템(FCS, Flight Control System)을 개발하고 검증하는 것은 매우 중요하며 장기간에 걸쳐 진행된다. 특히 항공기가 불안정한 특성이 발생될 수 있는 고받음각 상황에서 조종상실과 회복 과정 중 비행제어시스템의 정상적인 동작 여부의 검증은 비행시험 단계에서 비행시험의 위험성과 비용을 크게 감소시킬 수 있다. 그러나 비행시험 없이 실제 비행환경을 모사하여 동적 실험을 수행하고 비행제어시스템을 검증할 수 있는 시스템을 구성하는 것은 매우 어렵다. 공군사관학교 아음속 풍동실험실에서는 실제 비행환경과 매우 유사한 환경에서 동적특성을 파악할 수 있는 풍동실험 시스템을 구축하였다. 3자유도 짐벌과 리그를 개발하여 다자유도 가상비행(VFT, Virtual Flight Test) 풍동실험을 가능하게 하였고, 기존 폐회로 풍동 측정부를 개방형으로 개조하여 자유비행 풍동실험을 수행하였으며, 이를 통해 항공기 비행특성을 확인하고 비행제어시스템을 검증하였다. Developing and verifying the Flight Control System(FCS) in the aircraft development process is imperative and ongoing over a long period of time. Especially at a high angle of attack where unstable flight characteristic is likely to be shown, the verification of the FCS performance under the loss of control and recovery process can significantly reduce the risk and cost of flight testing during the flight test stage. However, developing a system capable of conducting dynamic tests and evaluating the FCS performance under simulated flight environments is challenging without a flight test. The Subsonic Wind Tunnel Laboratory of the Korea Air Force Academy established a wind tunnel test system capable of investigating dynamic characteristics in an environment similar to the actual flight environment. A three-degree of freedom gimbal and jig was developed to enable a multi-degree Virtual Flight Testing(VFT), the existing closed-circuit wind tunnel test section was converted into an open-type test section to conduct a free-flight wind tunnel test, and the aircraft flight characteristics were investigated and FCS was verified.

인증비행시험 안전관리 및 위험도 평가기법 연구

최주원,Choi, Joo-Won 항공우주시스템공학회 2011 항공우주시스템공학회지 Vol.5 No.1

Certification flight test is very risky and there are many hazards. Because the flight test is performed with the aircraft, that is safety and flight characteristics are not proven. And the test items and conditions are critical. If there is loss of aircraft during certification flight test, the certification program, development period can be delayed. Therefore, maintaining safety of the aircraft during flight test is very important. There are not much flight test experiences in Korea. However, developed nations has long history of flight test and experiences of flight test accidents. Based on these experiences, they has developed systematic management methods for the flight test safety. In this study, I would like to introduce safety management and risk assessment of the certification flight test.

Flight Test Results of Automatic Tilt Control for Small Scaled Tilt Rotor Aircraft

Youngshin Kang,Bumjin Park,Changsun Yoo,Yushin Kim,Samok Koo 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10

A small scaled flight model of the tilt rotor aircraft for the Smart UAV Program at KARI(Korea Aerospace Research Institute) has been developed and tested. Since the flight characteristics of a tilt rotor aircraft are new to KARI, the scaled model was used as a test bed to evaluate the flight control algorithm for the full scale Smart UAV. The flight test of the small scaled model was performed after various ground tests including tethered hover test. The control laws in initial phase consist of rate SAS feedbacks, control surface mixers, a rotor governor and a manual tilt command path. A rate feedback SCAS control law was used in order to evaluate the flight characteristics of the tilt rotor aircraft. As the flight test proceeds, an attitude SCAS was added because the attitude of aircraft was not clearly recognized due to the small size and fast speed of the aircraft. The first full conversion to a fixed wing mode was made through the manual tilt command by the external pilot. And then the automatic conversion was successfully performed by speed hold command in compliance with a pre-defined conversion corridor. Several problems unexpected were found during flight tests including oscillation of long period mode near helicopter mode, a delayed response to the altitude command and etc. The flight test results of the small scaled tilt rotor aircraft using an automatic tilt control is described in this paper and the solutions of the problems noticed in the flight test are presented.

Ground Test and Evaluation of a Flight Control System for Unmanned Aerial Vehicles

Jinyoung Suk,Jinhyung Kim 한국항공우주학회 2004 International Journal of Aeronautical and Space Sc Vol.5 No.1

UAV(Unmanned Aerial Vehicle) has become one of the most popular military/commercial aerial robots in the new millennium. In spite of all the advantages that UAVs inherently have, it is not an easy job to develop a UAV because it requires very systematic and complete approaches in full development envelop. The ground test and evaluation phase has the utmost importance in the sense 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 incomplete development procedure. In this research, a verification procedure of the whole airborne integrated system was conducted including the flight management system. An airborne flight control computer(FCC) senses the external environment from the peripheral devices and sends the control signal to the actuating system using the assigned control logic and flight test strategy. A ground test station controls the mission during the test while the downlink data are transferred from the flight management computer using the serial communication interface. The pilot control box also applies additional manual actuating commands. The whole system was tested/verified on the wind-tunnel system, which gave a good pitch control performance with a pre-specified flight test procedure. The ground test system guarantees the performance of fundamental functions of airborne electronic system for the future flight tests.

Instrumented flight test of flapping micro air vehicle

Kim, Jong Heon,Park, Chan Yik,Jun, Seung Moon,Parker, Gregory,Yoon, Kwang Joon,Chung, Dae Keun,Paik, Il Hyun,Kim, Jong Rok Emerald Group Publishing Limited 2013 Aircraft engineering and aerospace technology Vol.85 No.4

<B>Purpose</B> - The purpose of this paper is to present the procedure and results from instrumented flight test performed on the flapping MAVs being developed by the authors. A test is performed using a test measurement system to obtain the real characteristics of the flapping vehicles during their flight. <B>Design/methodology/approach</B> - The test is performed in an indoor flight test facility, equipped with a motion capture system and tracking cameras. Spatial position data are obtained from the vehicles with retro-reflective tracking markers attached. A quantitative analysis is carried out through the investigation and interpretation of the test data for the flight performance assessment of the vehicles. <B>Findings</B> - The finding of the analysis addresses that the test enabled the numerical measurement of vehicles' flying performance and shows the present vehicles have combined characteristics of both birds and insects. <B>Practical implications</B> - The test metrics attempted in the present study are applicable to the test and evaluation of general flapping micro air vehicles. Thus, this testing method will be useful for the development of future micro air vehicle system. <B>Originality/value</B> - Full-scale instrumented flight test and measurement of performance parameters of flapping micro air vehicles other than visual observation are unprecedented and expected to present the guideline of systematic test and evaluation of flapping micro air vehicles.

달 착륙선 지상시험모델을 이용한 가상비행시험 연구

류동영,이원범,권재욱,주광혁,심은섭 한국항공우주학회 2012 한국항공우주학회 학술발표회 논문집 Vol.2012 No.11

달 착륙선 지상시험모델의 지상시험의 목적은 비행모델 탐사선의 개발 이전에 주요 전자장비, 추진시스템, 제어 알고리즘 및 소프트웨어, 구조체의 핵심기술 및 체계운용기술 등의 전체 시스템에 대한 시연 및 검증이다. 계획된 지상시험은 추력기 클러스터링 시험과 가상비행시험으로 구성된다. 추력기 클러스터링 시험은 이착륙제어용 추력기의 클러스터 기술을 검증하기 위한 것이고, 가상비행시험은 추력기 클러스터링 시험과 이착륙 및 자세제어 추력기와 실시간 시뮬레이터를 이용하여 자유비행시험을 제외한 비행 시나리오에 따라 제어 및 운영 시스템과 착륙기술을 시험하기 위한 것이다. 향후에는 자유비행시험을 수행하여 추가적인 개선을 통하여 위험물 감지 및 회피 기술 시험 등에 활용할 예정이다. 본 논문에서는 달 착륙선 지상시험모델의 지면고정상태에서의 가상비행시험 방안에 대해 기술한다. The purposes of ground test of lunar lander demonstrator are to demonstrate and verify essential electronics, propulsion system, control algorithm, embedded software, structure and system operation technologies before developing the flight model lander. The planned ground test consists of thruster clustering test and virtual flight test. The thruster clustering test is to validate the clustering technology of five 200 newton thrusters. Although we do not perform actual free flight test in this research stage because of the safety issue, we test the control and operation system and landing technology by virtual flight test in which thrusters are actually fired by command of the control system according to the pre-defined flight scenario and simulated flight dynamics of the vehicle. In the future, as the free flight will be done, the Autonomous Landing and Hazard Avoidance Technology (ALHAT) are utilized through additional upgrade. This paper describes the plans about virtual flight test with lunar lander demonstrator being fixed on the ground.

축소형 틸트로터 무인기의 전자동 비행시험을 위한 문제해결과정

강영신,박범진,유창선,구삼옥,이장호 한국항공우주연구원 2009 항공우주기술 Vol.8 No.1

The ground integration test of Smart UAV has been performed according to the flight test plan. The flight test of full scaled model will be performed followed by 4 DOF ground rig test and a tethered hover test. Smart UAV is the first indigenous tiltrotor aircraft which can fly with fast cruise speed and take off or land vertically. In order to prove the flight control law of Smart UAV, the 40% scaled airplane was developed and have been tested. During flight test of small scaled model, many unique and unexpected problems occurred. After clearing these problems, fully automatic flight test was performed successfully. The experiences about many trouble shooting and resolving the problems would be basic material to avoid the unexpected but similar flight test problems hidden behind of the full scaled Smart UAV. This paper presents the detailed procedures of trouble shootings to solve the unique problems which occurred during the flight test of small scaled tiltrotor UAV. 스마트무인기는 수직이착륙과 고속비행이 동시에 가능하도록 헬리콥터와 고정익 항공기의 장점을 결합한 틸트로터 항공기이다. 현재 지상통합시험을 수행중이며, 4자유도 지상치구시험과 안전줄 호버시험을 거쳐 비행시험을 수행할 예정이다. 스마트무인기에 적용된 제어법칙을 검증하기 위해서 40%축소기를 개발하여 비행시험을 수행하였다. 비행시험결과 예측하기 어려웠던 틸트로터 항공기의 고유한 기술적인 문제점들이 발생하였으며, 이러한 문제점을 해결하여 전자동 비행시험을 완료하였다. 본 논문에서는 국내 최초로 수행된 축소형 틸트로터 항공기의 비행시험 과정 중에 발생한 주요한 문제점을 서술하고, 그 해결과정을 상세하게 기술하였다. 축소형 틸트로터 항공기의 전자동 비행시험 수행을 통해 경험한 시행착오와 개선사항은 향후 계획된 스마트 무인기의 실물기 비행시험을 성공할 수 있는 훌륭한 초석이 될 것이다.

동시다발적인 유도무기 비행시험 수요에 대응하기 위한 모델기반 비행시험 시스템 개발

박웅(Woong Park),이재천(Jae-Chon Lee) 한국산학기술학회 2019 한국산학기술학회논문지 Vol.20 No.1

유도무기 비행시험 시스템은 비행시험 중 여러 가지 상태를 실시간으로 감시하고 비상상황 발생 시 안전조치를 수행할 수 있어야 한다. 점차 복잡화, 광역화되고 있는 비행시험의 환경 변화 속에서 시험안전 확보의 중요성이 더욱 증대되고 있다. 또한 국내외 정세 변화와 전시작전권 전환 등으로 인하여 다수의 유도무기체계가 동시에 개발되어야 하고 동시에 연구개발 및 시험평가 기간단축을 통한 조기 전략화 및 예산절감도 요구되는 상황이다. 이에 따라 국내의 부족한 시험장 자원여건 하에서 비행시험 시 발생되는 위험은 증가하고 있으며 시험안전 확보를 위한 대책 마련이 시급한 실정이다. 이러한 요구에 부응하기 위해서 연구개발 초기 단계에서부터 비행시험 시스템의 문제를 식별하고 대처방안을 마련할 수 있도록 모델기반 비행시험 시스템 개발을 본 연구의 목표로 설정하였다. 구체적으로 유도무기 비행시험의 설계 및 검증 방법을 제안하였다. 제안된 방법은 선진 시험평가기관에서 연구하고 있는 Agile 방식의 Shift Left 시험평가 방법론과 항공우주분야에서의 시스템 참조모델을 활용하였다. 연구개발 단계에서 유도무기체계와 동시에 설계를 진행하고 비행시험 요구사항에 대한 상호 간의 결함을 조기에 식별하여 수정함으로써 시험평가 단계에서 수행하는 비행시험 시 발생될 위험을 완화할 수 있다. 또한 항공우주분야에서 복잡한 시스템을 통합하고 검증하는 데 적용하고 있는 참조모델을 기반으로 시스템 모델링 표준 언어인 SysML을 활용하여 모델기반 비행시험 시스템을 구현함으로써 다수의 유도무기 비행시험 설계에 적용할 수 있는 확장성을 갖고 있으며, 시뮬레이션 분석을 통해 비행시험에서 발생하는 문제를 조기에 식별하고 조치함으로써 시험평가 기간의 지연을 방지할 수 있다. Flight test systems should monitor various conditions in real time during flight tests and take safety measures in an emergency. The importance of ensuring test safety increases in more complicated and wider test environments. Also, due to the transition of wartime operational authority, many guided missile systems must be developed simultaneously. Early deployment and budget reduction by shortening the development and T&E periods are also necessary. Consequently, the risk of flight tests under the circumstance of inefficient test resources is increasing. To address this deficiency, a flight test system model using SysML was proposed in this study. The method of designing and verifying the test system is based on the agile shift left testing methodology of advanced T&E labs and utilizing a system reference model in the aerospace field. Through modeling and simulation analysis, early identification and correction of faults resulting from inconsistent test requirements can mitigate the risk of delays during the T&E phase of flight tests. Also, because the flight test system model was constructed using SysML, it can be applied to test various guided missile systems.

Flight Test of Flying Qualities for Helicopter Mode of Smart UAV

Young-shin Kang,Bum-jin Park,Am Cho,Chang-sun Yoo,Sam-Ok Koo 제어로봇시스템학회 2011 제어로봇시스템학회 국제학술대회 논문집 Vol.2011 No.10

Flight test results of flying qualities for Helicopter mode of Smart UAV are described. Flight test items in helicopter mode include manual and automatic stick control as well as hold and navigation flight including automatic take off and landing. One of the main purposes of helicopter mode flight test is to evaluate the handling qualities in low speed region where nacelle angles are greater than 80 deg. Rotor speed was controlled by the rotor governor without electric engine control after engine start. Position holding GPS stick mode and pitch/roll attitude SCAS (Stability and Control Augmentation System) showed good handling qualities performance during helicopter flight test. These control laws are also the basis both of conversion mode and airplane mode. All flight test described in this paper were controlled by external pilot (EP) using augmented GPS stick mode which comprise of 3 axis speed command and yaw rate command as well as position/heading hold at a neutral stick position. This paper presents the flight test result of flying qualities for helicopter mode of Smart UAV.