• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.116-118
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• 2005

STSAT-2 is first satellite which is scheduled to launch by first Korea launcher. After launch Ground station Baseband Controller(GBC) for operating STSAT-2 is now developing. GBC control data flow path between satellite operation computers and ground station antennas. and GBC count number of received data packets among demodulated audio signals from three antennas and set data flow path to good-receiving antenna automatically. In GBC two uplink FSK modulators(1.2kbps, 9.6kbps) and six downlink FSK demodulators(9.6kbps, 38.4kbps) are embedded. STSAT-2 GBC hardware is more simpler than STSAT-1 GBC by using FPGA in which all digital logic implemented. Now test and debugging of GBC hardware and Software(FPGA Code and GBC Manager Program) is well progressing in SaTReC, KAIST. This paper introduce GBC structure, functions and test results.

• Journal of Aerospace System Engineering
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• v.16 no.6
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• pp.74-80
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• 2022

The utilisation of small drones is becoming increasingly widespread particularly in the military sector. In this study, STANAG 4586, a standard interface for military unmanned aerial vehicles, was applied to a multicopter-type small drone to examine the suitability of the military system. To accomplish this, a small multi-copter vehicle was designed and manufactured, integrating a flight control computer, ground control system, and data link. Furthermore, flight control and ground control equipment software were developed by applying the STANAG 4586 interface, followed by HILS and flight tests.

• Journal of Satellite, Information and Communications
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• v.8 no.4
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• pp.111-116
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• 2013

Because LEO (Low Earth Orbit) satellite has very limited contact time between satellite and ground station, all telemetry data generated on satellite are stored in a mass memory and transmitted to the ground during the contact time. There are two downlink modes, real-time mode and playback mode. Only real-time data frames are transmitted to the ground in real-time mode, real-time and playback data frames stored into mass memory are transmitted to the ground in playback mode. In accordance with the data transmission rate, there are two downlink rates, low downlink rate and high downlink rate. This paper briefly introduces downlink interfaces and flight software of a LEO satellite developed in KARI. And it presents the telemetry storage method, real-time and playback downlink management method, and downlink channel and rate control method.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.235-240
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• 2002

This paper shows the desist concept of an ATS(Antenna Tracking Software) to control the movement of the MSC(Multi-Spectral Camera) antenna. The MSC has a two-axes directional X-band antenna for image transmission to KGS(KOMSAT2 Ground Station). The main objective of the ATS is to drive the APM(Antenna Pointing Mechanism) to the required elevation and the azimuth position according to an appropriate TPF(Tracking Parameter File). The ATS is implemented as one task of the SBC(Single Board Computer) software, which uses VxWorks as a real time OS. The ATS has several operational modes such as STANDBY mode, First EL mode, First AZ mode, Normal Operation mode, and so on. The ATS uses two PI controllers fur the velocity and the position loop respectively, to satisfy the requirements specification. In order to show the feasibility of the described design concept, the various simulations and the experiments are performed under specific test configuration.

• Journal of Astronomy and Space Sciences
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• v.27 no.3
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• pp.195-204
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• 2010

The optimal Earth-Moon transfer trajectory considering spacecraft's visibility from the Daejeon ground station visibility at both the trans lunar injection (TLI) and lunar orbit insertion (LOI) maneuvers is designed. Both the TLI and LOI maneuvers are assumed to be impulsive thrust. As the successful execution of the TLI and LOI maneuvers are crucial factors among the various lunar mission parameters, it is necessary to design an optimal lunar transfer trajectory which guarantees the visibility from a specified ground station while executing these maneuvers. The optimal Earth-Moon transfer trajectory is simulated by modifying the Korean Lunar Mission Design Software using Impulsive high Thrust Engine (KLMDS-ITE) which is developed in previous studies. Four different mission scenarios are established and simulated to analyze the effects of the spacecraft's visibility considerations at the TLI and LOI maneuvers. As a result, it is found that the optimal Earth-Moon transfer trajectory, guaranteeing the spacecraft's visibility from Daejeon ground station at both the TLI and LOI maneuvers, can be designed with slight changes in total amount of delta-Vs. About 1% difference is observed with the optimal trajectory when none of the visibility condition is guaranteed, and about 0.04% with the visibility condition is only guaranteed at the time of TLI maneuver. The spacecraft's mass which can delivered to the Moon, when both visibility conditions are secured is shown to be about 534 kg with assumptions of KSLV-2's on-orbit mass about 2.6 tons. To minimize total mission delta-Vs, it is strongly recommended that visibility conditions at both the TLI and LOI maneuvers should be simultaneously implemented to the trajectory optimization algorithm.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.2
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• pp.185-200
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• 2023

The Korea Augmentation Satellite System (KASS) is the first satellite navigation enhancement system in Korea developed in compliance with international standards. Technologies accumulated during the development process should be spread to industries such as academia and serve as the basis for developing the domestic satellite navigation field. This paper introduces the development process from design to implementation, testing, and verification of KASS control systems (KCS). First, development standards, milestones, requirements, and interface standards are presented as KCS development methods, and major functional design, physical design, and hardware/software implementation are described based on the allocated requirements. Subsequently, the verification environment, procedures, and results of the development product are covered and the developed operational and maintenance procedures are described. In addition, based on the experience gained through the development, suggestions were made for beneficial technology development and organization when promoting satellite navigation projects in the future. Since this work has important historical value for the development of domestic satellite navigation, it is expected that the development results will be shared with academia and industry in the future and be used as basic data for similar development.

• 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.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.1
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• pp.78-84
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• 2006

This paper describes UAV (Unmanned Aerial Vehicle) control system which employs PC104 modules. It is controlled by application program based on Linux OS. This application consists of both Linux device driver in kernel-space and user application in user-space. In order to get data required in the unmanned flight, external devices are connected to PC104 modules. We explain how Linux device drivers deal with data transmitted by external devices and we account for how the user application controls UAV on the basis of data processed in the device driver as well. Furthermore we look into the role of GCS (Ground Control Station) which is to monitor the state of UAV.

• Smart Structures and Systems
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• v.23 no.2
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• pp.155-171
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• 2019

In this study, Semi-active Tuned Mass Dampers (STMDs) are employed in order to cover the prevailing uncertainties and promote the efficiency of the Tuned Mass Dampers (TMDs) to mitigate undesirable structural vibrations. The damping ratio is determined using type-1 and type-2 Fuzzy Logic Controllers (T1 and T2 FLC) based on the response of the structure. In order to increase the efficiency of the FLC, the output membership functions are optimized using genetic algorithm. The results show that the proposed FLC can reduce the sensitivity of STMD to excitation records. The obtained results indicate the best operation for T1 FLC among the other control systems when the uncertainties are neglected. According to the irrefutable uncertainties, three supplies for these uncertainties such as time delay, sensors measurement noises and the differences between real and software model, are investigated. Considering these uncertainties, the efficiencies of T1 FLC, ground-hook velocity-based, displacement-based and TMD reduce significantly. The reduction rates for these algorithms are 12.66%, 26.43%, 20.98% and 21.77%, respectively. However, due to nonlinear behavior and considering a range of uncertainties in membership functions, T2 FLC with 7.2% reduction has robust performance against uncertainties compared to other controlling systems. Therefore, it can be used in actual applications more confidently.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.5
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• pp.774-780
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• 2011

The guidance control module is needed for control of a GPS guided bombs to improve the accuracy and availability of a conventional bomb. In this paper, we present the development of hardware design, software design and test environments of it. And we also show the process of the tests and the results verifying and proving for its required functions and performances through ground tests and flight tests.