• 전기전자학회논문지
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• 제2권2호
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• pp.270-277
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• 1998

네트워크 발전으로 인하여 제어시스템은 집중화에서 분산화 된 아키텍춰를 지향하고 있다. 그러나 이러한 제어시스템은 범용 운용 시스템을 기반으로 설계되어 공정처리에서 요구되는 실시간 성을 보장하기는 미흡한 점이 많아 플랜트의 제어설비로서 실시간 운영체제를 탑재한 제어시스템이 점차로 증가하고 있다. 본 논문에서는 분산제어 시스템의 기능을 위해 운영체제는 실시간 성을 보장하는 조건을 만족하도록 실시간 처리 능력, 실시간 응답의 신뢰성 및 멀티 프로세스의 기능구현에 중점을 두었으며, 이 운영체제의 바탕 위에 주요 공정처리의 기능인 루프, 로직의 가능한 처리 수를 분석하고, 이의 타당성을 검토하였다. 그리고 온라인 시 처리중인 데이터에 영향을 미치지 않는 시스템을 설계하고, 절체에 소비되는 시간을 측정 하였다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2003년도 학술대회논문집
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• pp.243-249
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• 2003

With distribution industrial control system, the use of tow 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.

• 반도체디스플레이기술학회지
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• 제22권4호
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• pp.148-153
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• 2023

A digital controller uses a microprocessor and is a controller implemented as a program. This method has the advantage of being more maintenance-friendly than existing analog controllers. However, it inevitably requires computation time to execute the internal program. Therefore, the digital controller uses a method of controlling the system at a certain cycle by considering this time, and this cycle is very closely related to the performance of the microprocessor used. In other words, in the case of very high performance, this control cycle can be shortened to near real time, but this may result in a disadvantage in terms of cost. In this paper, we propose a method to solve this problem by implementing two processors with slightly lower performance in a control system in a series-parallel structure. For this purpose, we will use a digital distributed control system and implement an experimental system to examine its effectiveness.

• 제어로봇시스템학회논문지
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• 제10권2호
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• pp.197-203
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• 2004

A real-time network in a distributed control system plays an important role for the reliable data transmission. Compared to the field-buses used in the past, TCP/IP protocol on the top of Ethered provides a compatibility between applications as well as an economical method to develop softwares. This paper proposes a modified TCP/IP structure for IEEE-1394 network, with which asynchronous and isochronous data transmission is selectively used for the real-time data transmission in a distributed control system. This paper also shows the performance of the proposed protocol by experiments.

• 한국자동차공학회논문집
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• 제10권4호
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• pp.175-180
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• 2002

In order to satisfy the requirements of time reduction and cost saving for development of electronic control systems(ECU) in automotive industry, the applications of a standardized real-time operating system(RTOS) and a communication protocol to ECUs are increased. In this study, a body control module(BCM) that employs OSEK/VDX(open system and corresponding interfaces for automotive electronics/vehicle distributed executive) OS tour the RTOS and a controller area network(CAN) fur the communication protocol is designed, and the performances of the system are evaluated. The BCM controls doors, mirrors, and windows of the vehicle through the in-vehicle network. To identify all the transmitted and received control messages, a PC connected with the CAN communication protocol behaves as a CAN bus emulator. The control system based upon in-vehicle network improves the system stability and reduces the number of wiring harness. Furthermore it is easy to maintain and simple to add new features because the system is designed based on the standards of RTOS and communication protocol.

• 전기학회논문지
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• 제58권1호
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• pp.63-68
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• 2009

As the complexity of the power system becomes higher, tests of the new devices, such as exciter and PCS(Power Conversion System) of the distributed generation sources, in the real operating condition are more important. However tests of the unverified devices in the real power system may cause hazardous malfunction of the system. In order to avoid this problem, power devices may be tested with the real-time simulators instead of the real power system. This paper presents an real-time multi machine power system simulator using PCs(Personal Computer) and Fast Ethernet. Developed real-time simulator performs the electro-mechanical dynamic simulation of multi-machine power system by the network distributed computing technique. Because the simulator consists of usual PCs and Fast Ethernet, it is possible to make up a simulation system very cheaper than the conventional real-time simulator which consists of dedicated expensive hardware devices. The performance of the developed simulator is tested and verified with the scaled model excitation system. The test which adjust the control parameters of the exciter is performed with the well-known New England 10 generator 39 bus sample power system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 심포지엄 논문집 정보 및 제어부문
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• pp.77-79
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• 2004

Because robot hardware architecture generally is consisted of a few sensors and motors connected to the central processing unit, this type of structure is led to time consuming and unreliable system. For analysis, one of the fundamental difficulties in real-time system is how to be bounded the time behavior of the system. When a distributed control network controls the robot, with a central computing hub that sets the goals for the robot, processes the sensor information and provides coordination targets for the joints. If the distributed system supposed to be connected to a control network, the joints have their own control processors that act in groups to maintain global stability, while also operating individually to provide local motor control. We try to analyze the architecture of network-based humanoid robot's leg part and deal with its application using the CAN(Controller Area Network) protocol.

• International Journal of Automotive Technology
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• 제6권2호
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• pp.107-117
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• 2005

A distributed hardware-in-the-loop simulation (HILS) platform is developed for designing an automotive engine control system. The HILS equipment consists of a widely used PC and commercial-off-the-shelf (COTS) I/O boards instead of a powerful computing system and custom-made I/O boards. The distributed structure of the HILS system supplements the lack of computing power. These features make the HILS equipment more cost-effective and flexible. The HILS uses an automatic code generation extension, REAL-TIME WORKSHOP$^{ (RTW$^{) of MATLAB$^{ tool-chain and RT-LAB$^{, which enables distributed simulation as well as the detection and generation of digital event between simulation time steps. The mean value engine model, which is used in control design phase, is imported into this HILS. The engine model is supplemented with some I/O subsystems and I/O boards to interface actual input and output signals in real-time. The I/O subsystems are designed to imitate real sensor signals with high fidelity as well as to convert the raw data of the I/O boards to the appropriate forms for proper interfaces. A lot of attention is paid to the generation of a precise crank/ earn signal which has the problem of quantization in a conventional fixed time step simulation. The detection of injection! command signal which occurs between simulation time steps are also successfully compensated. In order to prove the feasibility of the proposed environment, a simple PI controller for an air-to-fuel ratio (AFR) control is used. The proposed HILS environment and I/O systems are shown to be an efficient tool to develop various control functions and to validate the software and hardware of the engine control system.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1996년도 추계학술대회 논문
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• pp.133-137
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• 1996

This paper presents a new approach to the design of neural control system using digital signal processors in order to improve the precision and robustness. Robotic manipulators have bevome increasingly important in the field of flexible automation. High speed and high-precision trajectory tracking arre indispensable capabilities for their versatile application. the need to meet demanding control requirement in increasingly complex dynamical control systems under sygnificant uncertainties leads toward design of implementing real time neural control to provide an enhanced motion control for robotic manipulators. In this control scheme the ntworks intrduced are neural nets with dynamic neurouns whose dynamics are distributed over all the network nodes. The nets are trained by the distributed dynamic are distributed over all the network nodes. The nets are trained by the distributed dynamic back propagation algorithm. The proposed neural network control scheme is simple in structure fast in computation and suitable for implementation of real-time control, Performance of the neural controller is illustrated by simulation and experimental results for a SCAEA robot.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1324-1327
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• 1996

This paper presents an open architecture controller (OAC) for machining systems and describes the OAC testbed at Seoul National University. Because our OAC is designed for fully open systems, it does not depend on any specific hardware or software components. This openness includes software reusability which enables integration of a wide range of monitoring and control features. In addition to openness, our OAC system provides guaranteed real-time performance, an important requirement for advanced manufacturing.