• Journal of the Korea Society for Simulation
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• v.29 no.1
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• pp.1-9
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• 2020

The ballistic missile threat continues to increase with the proliferation of missile technology. In response to this threat, many kinds of interceptors have been emphasized over the years. For development of interceptor, systematic flight tests are essential. Flight tests provide valuable data that can be used to verify performance and confirm the technological progress of ballistic missile defense system including interceptor. However, during flight tests, civilians near the test region could be risk due to a lot of intercept debris. For this reason, reliable estimate of safety area for the flight tests should be preceded. In this study, prediction of safety area is performed through modeling and simulation. Firstly, behaviors of ballistic missile and interceptor are simulated for those entire phase including interception to obtain the relative intercept velocity and the relative impact angle. By using obtained data of kinetic energy, the fragment ejection velocity is calculated and fragment trajectories are simulated by considering drag, gravity and wind effects. Based on the debris field formation and hazard evaluation of debris, final safety area is calculated.

• Journal of Advanced Navigation Technology
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• v.19 no.4
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• pp.288-298
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• 2015

For the commercialization of unmanned aircraft, we must validate the safety of the air/ground collision alert systems (CAS). The validation procedure of CAS requires the flight test which is not only expensive but also dangerous. To alleviate this problem, we need the simulation based validation process for the CAS. We developed an integrated UAV simulation (IUS) environment which interconnect the flight simulator, the Matlab/Simulink, and a target avionics simulation model. We developed the collision warning module of the TCAS and tested using IUS and flight encounter models. Using IUS, we can evaluate the performance and reliability of a target avionic system at the preliminary design stage of a development life cycle.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.8
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• pp.681-688
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• 2021

This paper considers the trajectory and impact point dispersion analysis of the test launch vehicle (TLV). The analysis, which performed before and after its flight test on November 28, 2018, is described and verified by comparing with the flight test results. The six degree-offreedom (DOF) simulation is used to compute the dispersion of the trajectory, attitude, and impact point, where the launch vehicle performance variations and wind effects during the atmospheric phase are included. The impact area to guarantee the flight safety is determined using the results of the dispersion analysis. The flight test results confirm that the safe flight of TLV is performed within the predicted dispersion boundary.

• International Journal of Aeronautical and Space Sciences
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• v.1 no.2
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• pp.30-42
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• 2000

On-orbit thermal environment test of KOMPSAT was performed in early 1999. An analysis of the test data are addressed in this paper. For the thermal-environmental simulation of spacecraft bus, an artificial heating through the radiator zones and onto some critical heat-dissipating electronic boxes was made by Absorbed-heat Flux Method. Test data obtained in terms of temperature history were reduced into flight heater duty cycles and converted into the total electrical power required for spacecraft thermal control. Verification result of flight heaters dedicated to the bus thermal control is presented. Additionally, an exhaustive heating-control process for maintaining the spacecraft thermally safe and for realistic simulation of the orbital-thermal environment during the test are graphically shown. Qualitative suggestions to post-test model correlation are given in consequency of the analysis.

• Journal of Advanced Navigation Technology
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• v.8 no.2
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• pp.105-111
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• 2004

This paper describes the design of navigation system for an unmanned target drone which is operated by Korean army as for anti-air gun shooting training. Current target drone is operated by pilot control of on-board servo motor via remote control system. Automatic flight control system for the target drone greatly reduces work load of ground pilot and can increase application area of the drone. Most UAVs being operated nowdays use high-priced sensors as AHRS and IMU to measure the attitude, but those are costly. This paper introduces the development of low-cost automatic flight control system with low-cost sensors. The integrated automatic flight control system has been developed by integrating combining power module, switching module, monitoring module and RC receiver as an one module. The performance of navigation for low cost unmanned aerial vehicle, unmanned target drone as our test bed in this paper is verified by both Hardware in the loop simulation(HILS) to test performance of GPS as GPS output frequency high and results of flight test.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.52-56
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• 2004

Unmanned Aerial Vehicles (UAVs) are remotely piloted or self-piloted aircraft by inputted program in advance or artificial intelligence. In this study Aileron and Elevator are used to control the movement of airplane for horizontal and vertical flights about its longitudinal and lateral axis. In an introduction, the drone was linearly modeled by extracting aerodynamic parameter through flight test and simulation, lift and drag coefficient corresponding to angle of attack, changes of pitching moment coefficient. In the main subject, the flight simulation was performed after constructing hardware using TMS320F2812 from TI company and PID with lateral and longitudinal controller for horizontal and vertical flights. Flying characteristics of two system were estimated and compared through real flight test with hardware equipped algorithm and adaptive algorithm that was applied to consider external factors such as turbulence. In conclusion the control performance of the controller with proposed algorithm was streamlined at lateral and longitudinal controller respectively, we will discuss guidance command to pass way point.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.7
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• pp.1074-1080
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• 2015

In the last decades, the increasing interest in unmanned aerial vehicle(UAV) for military, surveillance, and rescue applications made necessary the development of flight control theory and body structure more and more efficient and fast. In this paper, we describe the design and performance of a prototype hexarotor UAV platform featuring an inertial measurement unit(IMU) based autonomous-flying for use in bluetooth communication environments. The proposed system comprises the construction of the test hexarotor platform, the implementation of an IMU, dynamic modeling and simulation in the hexarotor helicopter. Furthermore, the hexarotor helicopter with implemented IMU is connected with a micro controller unit(ARM-cortex) board. The P-PD control algorithm was used to control the hexarotor. We used the Matlab software to help us to tune the P-PD control parameters for quick response and minimizing the fluctuation. The control simulation and experiment on the real system are implemented in the test platform, evaluated and compared against each other.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.448-451
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• 2008

KARI is developing a satellite launch vehicle that is called KSLV(Korea Space Launch Vehicle)-I. During the flight, launch vehicles are exposed to aerodynamic heating conditions while flying at high Mach numbers in the atmosphere. KARI constructed Aerodynamic Thermal Simulation Facility to simulate aerodynamic heating on the ground. ATSF is a facility that can simulate given temperature profile using about 4,000 halogen heaters on fairing model. Aerodynamic heating profile is got from result of thermal analysis using MINIVER, Thermal Desktop, and SINDA/FLUINT. Aerodynamic heating test of fairing of KSLV-I was done using engineering model of payload fairing and Aerodynamic Thermal Simulation Facility. It was found that thermal analytic results show good agreement with aerodynamic heating test results within 6$^{\circ}$C at fairing inner surface. Also it was confirmed that maximum temperature of fairing nose-cone inner surface during flight is lower than allowable temperature limit.

• Journal of Sensor Science and Technology
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• v.22 no.1
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• pp.18-27
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• 2013

Real-time monitoring is one of the prime necessities in a weapon flight test that is required for the efficient and timely collection of large amounts of high-rate sampled data acquired by an event-trigger. The wireless sensor network is a good candidate to resolve this requirement, especially considering the inhospitable environment of a weapon flight test. In this paper, we propose a priority based multi-channel MAC protocol with CSMA/CA over a single radio for a real-time monitoring of a weapon flight test. Multi-channel transmissions of nodes can improve the network performance in wireless sensor networks. Our proposed MAC protocol has two operation modes: Normal mode and Priority Mode. In the normal mode, the node exploits the normal CSMA/CA mechanism. In the priority mode, the node has one of three grades - Class A, B, and C. The node uses a different CSMA/CA mechanism according to its grade that is determined by a signal level. High grade nodes can exploit more channels and lower backoff exponents than low ones, which allow high grade nodes to obtain more transmission opportunities. In addition, it can guarantee successful transmission of important data generated by high grade nodes. Simulation results show that the proposed MAC exhibits excellent performance in an event-triggered real-time application.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.10
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• pp.79-88
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• 2003

The paper presented here covers the work associated with the flight control law design, ground based and in flight simulation and handling qualities assessment of the Fly-by-Wire type Aircraft (FBWA). The FBWA configurations are of the same generic form of the Korean advanced trainer. The normal acceleration (Nz) and pitch rate (q) feedback control system is employed for longitudinal axis and roll rate (p) and lateral acceleration (Ny) feedback flight control law is developed in lateral/ directional axis. The flight tests for the FBW A dynamics evaluation were executed for the target aircraft (FBWA) on the IFS (In-Flight-Simulator) aircraft . The test results showed that Level 1 handling qualities for the most unstable flight regime and Level 1/2 for the landing approach flight regime were achieved. And the designed FBWA flight control law has revealed acceptable CHR (Cooper-Harper handling qualities Ratings).