• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.34 no.12
• /
• pp.82-89
• /
• 2006

This paper describes the development results of electrohydraulic actuation system which performs the attitude and trajectory control of pitch and yaw motion using thrust vector control for high altitude launching vehicle operated in high vacuum environment (altitude higher than 300 km). As compared with electrohydraulic actuation system for low altitude launch vehicle which operated under altitude of stratosphere, the intensified development requirements, newly adopted design and manufacturing technologies, newly developed test equipments and test results are summarized in this paper. The development test and evaluation of actuation system were successfully accomplished. The developed actuation system will be installed on KSLV-I after finishing verification of interface and integration compatibility with related other systems.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.41 no.10
• /
• pp.813-819
• /
• 2013

The authors have developed a test system for a hemispherical resonator gyroscope by using NI FPGA equipment. We have verified its suitability for the research of resonator gyroscopes through several tests: deriving resonance, controlling amplitudes, and estimating resonator parameters. The authors have adjusted a vibrating pattern to be aligned with the driving axis (or electromagnets). This pattern alignment is a basic and important operation of the FTR mode, which is one of operating modes for resonant gyroscopes.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39C no.3
• /
• pp.298-306
• /
• 2014

The railway signalling system for safe train operation regulates the train speed to ensure the safety distance between consecutive trains by using wayside facilities such as track circuits and interlocking systems. In addition, this signalling system controls the trackside equipment such as a railway point along the train line. This ground-equipment-based train control systems require high CAPEX and OPEX. To deal with these problems, the train control system using the on-board controller has been recently proposed and its related technologies have been widely studied. The on-board-controller-based train control system is that the on-board controller can directly control the trackside equipment on the train line. In addition, if this system is used, the wayside facilities can be simplified, and as a result, the efficient and cost-effective train control system can be realized. To this end, we have developed the prototypes of the on-board controller and wayside object control units which control the point and crossing gate and performed the integrated operation simulation in a testbed. In this paper, before the field test of the on-board-controller-based train control system, we perform the preliminary field trial including the installation test, wireless access test, interface test with other on-board devices, and normal operation test.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.8
• /
• pp.5513-5521
• /
• 2015

There is an operational efficiency problem about wayside equipment applied to the domestic low-density branch as the equipment has been installed and operated similarly in the mainline. On-board oriented train control system, which has been developed for train safety and operation efficiency, ensures safe train operation without expensive ground control signal devices. Such system consists of on-board control system, wayside control system, and local control system. In this paper, the details of tests such as suitability test, communication test, and interface test are described by installing the on-board control system and wayside control system in field. Installation tests include checking power, voltage, cable connection, LED status, etc. Field applicability of the developed system is also verified through the dynamic operation tests with diverse scenarios, which are performed on the virtual line similar to the real environment including switch machine and level crossing gate. Dynamic operation tests were conducted for total 7 scenarios, and several tests were repeated for each scenario. The elapsed time for each operation was computed by analyzing main process log, and we could check that each operation was accomplished within several seconds. Furthermore, the developed system was verified through field test with an accredited institute, and testing certificates were issued.

• Journal of the Korean Society for Precision Engineering
• /
• v.6 no.4
• /
• pp.21-31
• /
• 1989

역사적으로 CNC기술이 생산성향상에 기여한바는 매우 크다. 최근에는 고도의 생산성을 추구하는 CNC공작기계는 수요자들의 요구에 부응하여 관련업계는 CNC 기술의 발전을 더욱 가속화 시키고 있다. 오늘날의 CNC는 더욱 향상된 Computer Architecture에 적합한 Software System과 고속, 고집적의 소자기술을 결합한 것이라 볼 수 있으며, 그 결과는 생산을 자동화 하고 전체를 하나의 system화 하려는 요구에 부응하고 유연(Flexible)하며, 사용하기에 편리하고(User-friend- ly), 신뢰성과 높은 생산성을 갖추고 있다. 새로운 CNC 기술이 요구되는 응용분야는 고도로 자동 화 되고 결합 된 FMS에서 부터 단축제어용에 이르기까지 매우 광범위하다. 3축의 Milling, 6축 Machining Center, 전용기 등 Stand-alone 기계들을 위주로한 중소형기계 공장에 적합한 CNC 기술이 개발되고 있는 동시에 CELL LEVEL, 좀더 큰 규모의 FMS 또는 그 이상으로 자동화된 system을 구성하 기 위하여 많은 새로운 기능이 요구되고 종래의 CNC와는 다른 역할의 변화가 필요하다. 실제로는 많은 경우에 이러한 두가지의 응용이 공존하고 있으며, CNC의 기능이나 성능을 희생하지 않고 동일한 Hardware로 여러가지의 응용을 만족시켜야 한다. 생산공정과 생산기술의 변화가 반영되어야 하며, Control 기술도 변화하고 있다. 유연하고 확장가능한 Software, Hardware 구조의 CNC가 실제적으로 가장 Cost-effective한 해결책이다.

• Proceedings of the KIEE Conference
• /
• 2006.07c
• /
• pp.1576-1577
• /
• 2006

22kV, 60kA급 커패시터 펄스전원장치의 스위치로 신뢰성과 제어성이 우수한 반도체 스위치인 싸이리스터(Thyristor)를 사용하였다. 싸이리스터 규격의 적합성을 검토하였으며 펄스파워발생환경에서 신뢰성을 높이기 위한 대책을 고려하였다. 실험결과와 모사실험 결과를 비교하였다.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1996.05a
• /
• pp.333-339
• /
• 1996

최근에 개량형 또는 수동형 발전소의 디지탈 보호계통에서 소프트웨어의 역할이 증가함에 따라 공통원인고장의 가능성이 중요한 관심사항이 되었다. 아날로그 보호계통에서는 공통원인고장 가능성이 없었으며, 비록 공통원인고장이 발생하더라도 부식과 조기마모와 같은 과정은 천천히 진행되므로 이제까지 큰 문제가 되지 않았다. 이러한 아날로그 설계의 특징은 컴퓨터를 이용한 소프트웨어를 포함하고 있는 디지탈계통에는 적용되지 않는다. 본 논문에서는 소프트웨어의 공통원인고장을 고려하여 원자로 보호계통의 적합성을 다양성 및 심층방어 측면에서 해석할 수 있는 방법론에 대하여 논의한다. 본 논문의 결과는 추후에 한국형 차세대 원자로(KNGR)의 계측제어계통 설계를 위하여 수행하여야 할 다양성 및 심층방어 해석의 방법론 정립에 도움이 될 것으로 예상된다.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.37 no.5
• /
• pp.46-55
• /
• 2000

This paper presents a direct adaptive control of robot system using chaotic neural networks and PD controller. The chaotic neural networks have robust nonlinear dynamic characteristics because of the sufficient nonlinearity in neuron itself, and the additional self-feedback and inter-connecting weights between neurons in same layer. Since the structure and the learning method are not appropriate for applying in control system, this neural networks have not been applied. In this paper, a modified chaotic neural networks is presented for dynamic control system. To evaluate the performance of the proposed neural networks, these networks are applied to the trajectory control of the three-axis PUMA robot. The structure of controller consists of PD controller and chaotic neural networks in parallel for conforming the stability in initial learning phase. Therefore, the chaotic neural network controller acts as a compensating controller of PD controller.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.12
• /
• pp.6427-6433
• /
• 2013

For trains to run safely and quickly, the train should always follow the preceding train at a proper spacing. For this purpose, a certain distance between the stations is set for each block section. For the safe operation of trains in one block section, only one train service for an automatic block system is needed. The existing block system is composed an ABS, which is a linked track circuit and line sideway system through the interlocking system. The interlocking system is being replaced with a domestic electronic interlocking system. On the other hand, the block system still uses the relay format of an analog system, and is independently installed of the line sideway systems. Therefore, the existing block system has many problems in terms of construction and maintenance. In addition, the existing domestic line is used for ABS and LEU , which is installed separately, despite the train being controlled by the information of the same signal at the same location. This is not efficient in terms of each product price and the maintenance costs. This paper introduces an integrated electronic block system and the field test results. The field test was carried out through a periodic inspection performed eight times from January to late August.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.42 no.2 s.302
• /
• pp.39-48
• /
• 2005

In this paper, we implement the multimedia remote control system by using existing internet service or wired online. We also provide user-friendly convenient environment with developed application program named EzPlay and PC-EPG. The multimedia remote control system consists of integrated wireless transceiver of PC and TV connected USB type and the users can easily use lots of contents because EzPlay program provides appropriate UI mode on the PC and TV screen. The unposed system can operate real-time playing, reserved video receding and data storing function using internet mesh based on signal detecting control theory. The PC-EPG system is implemented by server/client web program and the client program based on visual C++/MFC processes data storing in client computer through TCP/IP. It also provides intelligent function that constructs database according to user's preference.