• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1618-1622
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• 2004

In this paper, the linearly interpolated PRC(Pseudo Range Correction) regenerating algorithm was applied to improve the DGPS(Differential Global Positioning System) positioning accuracy at user's spot by using the various PRC information obtained from multi-DGPS reference stations. The PRC information of each GPS satellite is not varying rapidly; it is possible to assume that the variation of PRC information of each GPS satellite is linear. So the linearly interpolated PRC regenerating algorithm can be applied to improve the DGPS positioning accuracy at user's spot by using the various PRC information obtained from multi-DGPS reference stations. To test the performance of the linearly interpolated PRC regenerating algorithm, maritime DGPS reference stations' PRC data was used in RTCM format. 11 maritime DGPS reference stations are in service providing DGPS information to public since 1999. Two set of 3 DGPS reference stations are selected to compare the performance of the linearly interpolated PRC regenerating algorithm. The DGPS positioning accuracy was dramatically improved about 40%. Linearly interpolated PRC regenerating algorithm adopted multi-channel DGPS receiver will be developed in near future.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.1
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• pp.1-9
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• 2000

In this paper, we design a robust output feedback controller for robot manipulators with bounded parametric uncertainties using high-gain observer. The proposed control scheme with integral action improves tracking error due to limit of the robust feedback gains. High-gain observer is used to solve the noise problem with the joint velocity measurement. This controller avoids the limitation on the variation of unknown parameters and guarantees the uniformly ultimate boundedness of the closed-loop system. The performance of the proposed method is demonstrated by simulation on a 2-link manipulator.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.1
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• pp.86-94
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• 2018

As the use of software is increasing in aircraft system, an exposure to the threat of safety and security also continues to grow. Although certification criteria for software safety such as DO-178C have already been established, specific certification criteria for software security have not yet been included. Recently DO-326A, DO-356 and DO-355 have been published separately for aircraft and system airworthiness security certification criteria. However, to comply individual certification criteria and procedures, it requires the additional cost and effort. Therefore, this paper proposes the efficient integrated certification criteria saving cost, effort and time by combining the certification criteria for software safety and security.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06b
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• pp.90-93
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• 2011

항공 전자 시스템은 다양하고 중요한 임무를 수행하는 다양한 전자 장치들로 이루어지며 전자 장치들은 점차 통합 구조 시스템(IMA, Integrated Modular Avionics)으로 구성되고 있다. 이러한 통합 구조 시스템은 전자 장치의 다양한 종류와 육중한 중량을 이유로 단일 컴퓨터 환경에서 구성된다. 이러한 이유로 항공 전자 시스템에서 사용되는 응용프로그램들 또한 단일 컴퓨터에서 효율적으로 통합될 수 있어야 한다. 응용프로그램들은 각기 다른 기관에서 개발되는 경우가 많으며 그중 일부는 다른 항공 전자 시스템에 재사용 될 수 있다. 이와 같은 통합구조에서 갖는 응용프로그램들의 특성을 고려하여 시 공간적으로 분리된 파티션으로 구분하는 ARINC 653과 같은 표준이 등장 하였다. 가상화 기술은 여러 개의 가상머신을 제공하고 다양한 장치에 대하여 에뮬레이션 함으로써 하나의 가상 머신은 ARINC 653의 파티션 개념을 적용하는데 충분한 잠재력을 가지고 있다. ARINC 653을 많은 타겟 운영체제나 반 가상화 환경에서 적용된 예는 많다. 하지만 아직까지 전 가상화 환경에서 ARINC 653을 적용한 예는 없다. 따라서 본 논문에서는 두 종류의 전 가상화 환경(VMware, VirtualBox)에서 ARINC 653을 적용하기 위한 구조를 제시하고 구현한다.

• Journal of Advanced Navigation Technology
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• v.13 no.5
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• pp.630-638
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• 2009

In this paper, we propose a new SCADE-based integrated simulator for aircraft mid-air collision avoidance. The new simulator is designed to provide a convenient simulation environment for analyzing the limitations of the existing collision avoidance system(CAS) and for realizing more realistic collision environment into the CAS performance evaluation. Furthermore, we have developed a scenario editor for TCAS-II performance analysis to simulate actual flight environment which is difficult to experiment. The performance of the proposed simulator for typical collision scenarios is demonstrated by simulation using the proposed scenario editor.

• Journal of Advanced Navigation Technology
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• v.13 no.5
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• pp.705-713
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• 2009

This paper proposes CORBA-based visual servoing system of humanoid robot. To effectively control the humanoid robot which is connected to network, it needs to define necessary services for visual servoing as distribution object, and realize them in the middleware. For realizing it following services should be addressed. Naming service for searching a necessary service with unique name assigned to each object, image service for supplying image obtained from stereo camera. In the experiment, we show the result of balloon tracking and bursting that the robot tracks balloons as target objects in the real time, and if a balloon stop for a certain time, then the robot bursts the balloon.

• Journal of Advanced Navigation Technology
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• v.5 no.2
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• pp.134-140
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• 2001

Ultra Wideband(UWB) system uses wide band signal, which power spectral density likes as a noise floor, so UWB system can be used high speed communication without interfering with other communication system. As this system doesn't use carrier, its structure would be very simple and consume very low power. But conventional UWB system uses Pulse Positioning Modulation(PPM) Method. Therefore it could be to produce discrete power spectrum which decreases system efficiency unintentionally. For eliminating discrete power spectrum and further Euclidean distance, we propose UWB system using Antipodal signal. And we design and simulate antipodal tranceiver using Advanced Design System(ADS).

• Journal of Advanced Navigation Technology
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• v.3 no.2
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• pp.174-184
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• 1999

In this paper, the equations which can be used to calculate the minimum series stabilizing resistance and /or the minimum parallel stabilizing conductance using the S parameters of an active device has been derived. The equation derived can be used to design a stabilizing circuit of minimum loss of a maximum available gain of a device when the circuit is adopted. For the case of KGF1254B which can be used at 1.9 GHz, the circuit proposed in this paper reduce the maximum available gain by 1 dB, while conventional simple resistor circuit reduce it by 5.2 dB.

• Journal of Advanced Navigation Technology
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• v.10 no.1
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• pp.1-6
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• 2006

In this paper, we have analyzed transmission time for WAP over CDMA using turbo code scheme. In order for SAR to improve the transfer capability, the transmission of messages have been simulated using a fragmentation that begins with the total package and incremental fragmentation for each layer using the WTP to define the resultant packet size and the level of fragmentation for each proceeding layer. This turbo code scheme decreases transmission time of RLP baseband packets by sending packets. From the results, we were able to obtain packet transmission time and optimal WTP packet size for WAP over CDMA in a Rician fading channel.

• Journal of Advanced Navigation Technology
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• v.16 no.4
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• pp.571-577
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• 2012

In this paper, we design a flight controller using a dynamic compensator for a small unmanned aerial vehicle. The proposed method ensures flight stability during altitude holding and waypoints passing by improving the transient response and steady state error. The control system consists of dual feedback loops with an inner loop and a outer loop. The inner loop has a PD controller to improves the transient response and the outer loop has a dynamic compensator to reduce overshoot in the transient response and improve the steady state error. The performance of the proposed method is evaluated by flight test on a small UAV.