• Journal of Advanced Navigation Technology
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• v.27 no.5
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• pp.574-579
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• 2023

The radar flight test has many restrictions on simulating various targets, clutter and jamming signal. Therefore, in this study, a radar HILS system that performs a radar operation simulation function according to an operation scenario was developed. Radar HILS simulates the radar mission environment through radar beam operation simulation, radar operation control, simulated signal generation, and flight attitude simulation.. HILS generates and modulates simulated target signals(single, multiple targets) containing radar mission environments(clutter, jamming etc.) based on flight scenarios, and transmits them to AESA radar over RF. And Scenario-based radar performance was verified by detecting simulated targets and confirming detection results.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.7
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• pp.529-536
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• 2020

Reaction Control System of the third stage of the Korean Space Launch Vehicle II conducts roll control and 3 axis control throughout third stage engine start, satellite separation, and collision and contamination avoidance maneuver. Reaction control system consumes its propellant in each thruster operation. Hence, loading of proper amount of the propellant is important for mission success. It is needed to have a rough estimation method of propellant consumption during the flight. In this paper, we developed a energy equation using pressure and temperature data which are acquired in the on-board reaction control system. We constructed a test system which is similar with the on-board reaction control system to verify the energy equation. Test results using deionized water were compared with estimated propellant consumption. We also conducted an error analysis of the energy equation. We also presented the propellant consumption result of a system level operation test.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.8
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• pp.50-55
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• 2005

An advanced method of Relaxed Static Stability (RSS) is utilized for improving the aerodynamic performance of modern version supersonic jet fighter aircraft. The laws of flight control system utilize RSS criteria in both longitudinal and lateral-directional axes to achieve performance enhancements. Particularly, the design of longitudinal control laws for utilizing RSS methods greatly affects the performance of the aircraft in Air-to-Air Tracking and Air-to-Ground modes, which improves weapon delivery. In the area of Air-to-Air Tracking, the development of longitudinal control laws aids in the fine tracking and gross acquisition of other aircraft. This paper proposes that new concept of longitudinal control law introduce in order to improve fine tracking performance in air-to-air tracking maneuver. Result of HQS pilot simulation and flight test, fine tracking performance improve without degradation of gross acquisition when new concept of control law is applied.

• Journal of Convergence for Information Technology
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• v.7 no.5
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• pp.75-82
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• 2017

Recently, as the roles and utilization fields of UAV become more diverse, demand for high - level mission has been increasing. To solve this issue, researches on the operation of multiple small UAVs and related systems have been actively carried out. The multiple small UAVs based application system has a problem that the task complexity of control personnel increases because the control personnel must continuously control and manage several small UAVs. Hence, it is necessary to develop a software platform that can perform efficient control in order to employ a multiple small UAVs based application system successfully. In this paper, we propose an effective ground control software platform for application systems using multiple small UAVs. We first analyze the requirements for the software platform, and design and implement software based on the analysis. Simulation using the X-plane flight simulator shows that multiple flight data are effectively displayed and that the image data transmitted from many small UAVs are simultaneously displayed in real time.

• International Journal of Aeronautical and Space Sciences
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• v.4 no.1
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• pp.1-8
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• 2003

In this paper, a reconfigurable flight control system is designed by applying the sliding mode control scheme. The sliding mode control method is a nonlinear control method which has been widely used because of its merits such as robustness and flexibility. In the sliding mode controller design, the signum function is usually included, but it causes the undesirable chattering problem. The chattering phenomenon can be avoided by using the saturation function instead of signum function. However, the boundary layer of the sliding surface should be carefully treated because of the use of the saturation function. In contrast to the conventional approaches, the thickness of the boundary layer of our approach does not need to be small. The reachability to the boundary layer is guaranteed by the sliding mode controller. The fault detection and isolation process is operated based on a sliding mode observer. To evaluate the reconfiguration performance, a numerical simulation using six degree-of-freedom aircraft dynamics is performed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.610-613
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• 1995

In addition to propulsive force to a flying vehicle, a rocket propulsion system can provide moments ro rotatate the flying vehicle and thus provide control of the vehicle's attitude and flight path. By controlling the direction of the thrust vectors, it is possible to control a vehicle's pitch, yaw, and roll motions. In this paper, we will introduce general thrust vector control mechanisms.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.12
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• pp.1181-1188
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• 2014

In this paper, we propose a novel concept foran unmanned delivery service using a cooperative heterogeneous unmanned system consisting of a self-driving car and an unmanned aerial vehicle (UAV). The proposed concept is suitable to deliver parcels in high-density and high-rise urban or residential areas. In order to achieve the proposed concept, we will develop acooperative heterogeneous unmanned system. Customers can order goods using a smartphone application and the order information, including the position of the customer and the order time, and the package is transported automatically by the unmanned systems. The system assigns the tasks suitable for each unmanned vehicle by analyzing it based on map information. Performance is validated by experiments consisting of autonomous driving and flight tests in a real environment. For more evaluation, the landing position error analysis is performed using circular error probability (CEP).

• International Journal of Aeronautical and Space Sciences
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• v.2 no.2
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• pp.82-94
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• 2001

The purpose of this paper is to analyze the static and dynamic stability-of the unmanned airship under development ; the target airship's over-all length of hull is 50m and the maximum diameter is 12.5m. For the analysis, the dynamic model of an airship was defined and both the nonlinear and linear dynamic equations of motion were derived. Two different configuration models (KA002Y and KA003Y) of the airship were used for the target model of the static stability analysis and the dynamic stability analysis. From the result of analyses, though the airship is unstable in static stability, dynamic characteristics of the airship can provide the stable dynamic stability. All of the results, airship models and dynamic flight equations will be an important basement and basic information for the next step of developing the automatic flight control system(AFCS) and the stability augmentation system(SAS) for the unmanned airship as well as for the stratospheric airship in the future.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.21 no.3
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• pp.1-8
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• 2013

An application of adaptive flight controller is required for the non-linear and high uncertain system that configuration of tiltrotor aircraft is dramatically changed from rotary wing mode to fixed wing mode. In this paper, the applicable adaptive controller for the tiltrotor aircraft was designed using Neural Networks and DMI (Dynamic Model Inversion). The performance of the SCAS (Stability and Control Augmentation System) was simulated against manned military specification, using the fullscale model of 'Smart UAV(Unmanned Aerial Vehicle)' developed by Korea Aerospace Research Institute. And Neural Networks based adaptive controller was verified through its whole operating envelope using the established HQ (Handling Quality) criteria.

• Aerospace Engineering and Technology
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• v.9 no.2
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• pp.153-160
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• 2010

Air Data Recording System (ADRS) is the flight data recorder for the SmartUAV development. ADRS of the low cost designed for the SmartUAV has been developed and tested through the ground test. ADRS is the reconstructing data acquisition system and can be programmed automation controller. This paper focuses on the design aspects of the hardware and software. The hardware aspects of the ADRS include details about the hardware configurations for the interfaces with the Digital Flight Control Computer(DFCC) and sensors, components modifications. The software section describes the ADRS Operating System(OS) and data flow for archived files. Finally, ADRS-based results of the SmartUAV that include the Iron-bird test, system interface test and ground test are presented.