• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.298-300
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• 2005

오늘날 공장 자동화에 이용되는 필드버스 네트워크는 많은 종류가 있으며 각각의 특징 및 장단점을 가지고 다양하게 이용되고 있다. 이러한 필드버스 네트워크용 프로토콜은 서로 다른 특징으로 인하여 관리자가 효율적으로 네트워크를 관리하는데 어려움이 크다. 본 논문에서는 이러한 이기종의 필드버스 네트워크를 통합할 수 있는 필드버스 네트워크 프로토콜 변환 게이트웨이를 설계 및 구현하였다.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1757-1762
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• 2003

With distribution industrial control system, the use of low cost to achieve a highly reliable and safe system in real time distributed embedded application is proposed. This developed intelligent node is based on two microcontrollers, one for the execution of the application code, also as master controller for ensuring the real time control & the logic operation with PLD and other for communication task and the easy control execution, i.e., I/O digital input, digital output and interrupting. This paper also presents where the case NCS (Networked control system) with LonTalk protocol is applied for the filtration process control system of a small water treatment plant.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.49-51
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• 2004

This paper presents a realization of fault detection algorithm and Fieldbus based communication for condition monitoring of check valve. We first acquired the AE(Acoustic Emission) sensor data at the KAERI check valve test loop, extract fault features through the learned Neural network, and send the processed data to a remote site. The overall system has been implemented and experimental results are given to show its effectiveness.

• Journal of Sensor Science and Technology
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• v.16 no.1
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• pp.52-61
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• 2007

Networked embedded systems using the smart device and fieldbus technologies are now found in many industrial fields including process automation and automobiles. However the discrepancy between a node's view of current time and the rest of the system can cause many difficulties in the design and implementation of a networked system. To provide a networked system with a global reference time, the problem of clock synchronization has been intensively studied over the decades. However, many of the existing solutions, which are mainly developed for large scale distributed computer systems, cannot be directly applied to embedded systems. This paper presents a fault-tolerant clock synchronization technique that can be used for a low-cost embedded system using a CAN bus. The effectiveness of the proposed method is demonstrated with a set of microcontrollers and DC motor-based actuators.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.470-473
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• 2002

Most networks for automation are tuned to an expected traffic at their design stage. During their actual operations, however, the networks experience considerable changes in traffic from time to time. These traffic changes caused by common events like machine failure and production schedule change may adversely affect the network performance and, in turn, the performance of the connected devices. This paper presents communication delay model for Profibus token passing protocol, and introduces TTR selection methods to maintain a uniform level of network performance at all stations under changing network traffic.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.4
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• pp.281-287
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• 2002

This paper investigates on the feasibility of fuzzy logic control for networked control systems. In order to evaluate its feasibility, a networked control system for motor speed control is implemented on a Profibus-DP network. The NCS consists of several inde-pendent, but interacting processes running on two separate stations. By using this NCS, the network-induced delay is analyzed to find the cause and effect of the delay. Furthermore, in order to prove the feasibility, the fuzzy logic controller's performance is compared with those of conventional PID controllers. Based on the experimental results, the fuzzy logic controller can be a viable choice far NCS due to its robustness against parameter uncertainty.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.223-226
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• 2003

This paper presents a realization of sensor signal processing(noise filtering) and Fieldbus based communication for condition monitoring of check valve. we first acquired the AE(Acoustic Emission) sensor data at the KAERI check valve test loop, and their frequencies were analyzed to find the informative band. To reject background noises, bandpass filters have been designed. Also, to send the processed data to a remote site, wired communication facility has been realized via DeviceNet.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.319-324
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• 2005

The interface between host processor and the ShortStack Micro Server may be a Serial Communication Interface(SCI). The LonWorks control module with a high performance is developed, which is composed of the 8 bit PIC Microprocessor for host processor and the smart neuron chip for the ShoretStack Micro Server. This intelligent control board is verified as proceeding the various function tests from experimental system with an boost pump and inverter driving systems. It is also confirmed that the developed control module provides stably 0-10VDC linear signal to the input signal of inverter driving system for varying the induction motor speed. Thus, the experimental results show that the fabricating intelligent board carried out very well the various functions in the wide operating ranges of boost pump system. This developed control module expect to apply to industrial fields to require the comparatively exact control and monitoring such as multi-motor driving system with inverter, variable air volume system and the boost pump water supply systems.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.855-857
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• 2004

유지 보수가 용이하고 제어 성능이 좋은 BLDC 모터가 최근 자동화 공정에서 많이 사용되고 있다. 이와 같은 자동화 환경에서 분산되어 있는 각종 장치들을 제어하고 감시하기 위해서는 네트워크 시스템이 필수적이다. 여러 대의 전동기가 연계하여 단일 작업을 수행하는 경우 네트워크 기반의 실시간 제어가 더욱 중요하다. 본 논문에서는 CAN 네트워크를 사용한 다중 BLDC모터의 속도제어 시스템을 구현하여 개별 노드로 구성된 각각의 모터가 같은 정속도 회전을 하도록 한다.

• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.677-679
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• 1999

In this paper, an integration tool for the factory automation communication is proposed. It can apply to three kinds of Fieldbus, Manufacturing Message Specification and Personal Digital Assistance based systems in the factory environment. This paper focuses on the development of the testing tool and object-oriented design concepts for the synthesis of communication modules from the factory level to the field level. The integration of each communication module in the distributed environment gains importance for the realization of heterogeneous information processing systems.