Earticle

This study proposes a distributed integrated control architecture based on Direct Digital Control(DDC) as an alternative to conventional centralized Distributed Control System(DCS) structures for a Canadian oil sands pilot plant, and theoretically analyzes its control characteristics and operational optimization potential. The target process consists of production and circulation, separation, water treatment, partial upgrading, and utility systems, and exhibits complex characteristics such as multiphase flow, high viscosity, time delay, strong coupling, and operation under extreme environmental conditions. In this study, an integrated control architecture combining independent DDC nodes for each process unit with a supervisory control layer is presented. A control model considering the coupling relationships among production, separation, water treatment, and upgrading processes is formulated, along with an objective function for energy optimization. Furthermore, through literature-based comparison and system architecture analysis, it is demonstrated that the DDC-based structure is suitable for oil sands pilot plants in terms of responsiveness, scalability, fault isolation, and energy efficiency.

Distributed mobility management (DMM) is currently being researched and standardized in academia and standardization development organizations for the purpose of overcoming the major issues of existing centralized mobility management. The most recent DMM protocols are being redesigned with regard to the control and data plane separation concept. However, at present, there is no solution for supporting IP multicast listeners in such new DMM environments. In this paper, we review ongoing academic research works, standardization activities and propose an IP multicast mobility design for the DMM environment using the control and data plane concept.

본 논문에서는 함정용 ICCP(Impressed Current Cathodic Protection) 정류기에 적용되어 온 구역 단위 대표 전위 기반 제어 구조의 공간 분해능 및 제어 단위 한계를 분석하고, 이를 개선하기 위한 채널 단위 독립 제어 기반 분산 제어 아키텍처를 제안한다. 제안 구조는 기준전극–양극 쌍을 최소 제어 단위로 정의하고, 기준전위 수집–제 어 연산–전류 출력 경로를 분리하여 채널별 병렬 제어 루프가 독립적으로 동작하도록 설계되었다. 제안 구조의 타 당성은 고객 요구사항에 기반한 합/부 판정 체계를 통해 검증하였으며, 실환경에서 반복 재현이 어려운 전위 비대칭 및 국부 외란 조건을 HIL 기반 시험 환경으로 구성하여 구조적 독립성과 제어 동작 특성을 확인하였다. 본 연구는 기존 구조 대비 수치적 성능 비교가 아니라, 제어 단위 재정의를 통한 분산 제어 아키텍처의 설계 타당성을 구조적 으로 입증하였다는 점에서 의의를 가진다.

This paper analyzes the spatial resolution and control-unit limitations of the conventional zonebased representative potential control structure applied to naval ICCP rectifiers and proposes a channel-level independent distributed control architecture to address these limitations. In the proposed structure, each reference electrode–anode pair is defined as a minimal control unit, and the processes of potential acquisition, control computation, and current output are logically separated to enable parallel and independent control loops for each channel. The validity of the proposed architecture is verified through a requirement-based pass/fail evaluation framework. A hardwarein- the-loop (HIL) test environment was constructed to emulate asymmetric potential distributions and localized disturbance conditions that are difficult to reproduce in real operational environments. Experimental results confirm the structural independence and operational characteristics of the channel-level control loops. Rather than focusing on numerical performance optimization against the conventional structure, this study demonstrates the structural design validity of a distributed control architecture achieved through the redefinition of the control unit.

Digital twins are a core technology for smart factories, but the high cost and complexity of existing industrial protocols like OPC-UA act as significant barriers to entry for resource-constrained small and medium-sized enterprises (SMEs). This study proposes a ‘modular lightweight architecture for discrete manufacturing process control’ to address these issues. It eliminates dependency on specific middleware, utilizing only the universal game engine Unity and standard TCP/IP socket communication. The proposed architecture functionally separates visualization (Unity server) and control logic (external client), enhancing system flexibility and minimizing communication overhead. To demonstrate the architecture's excellence, a virtual conveyor belt control experiment was conducted in a distributed LAN environment simulating an actual manufacturing site. The results confirmed stable response performance with an average round-trip time (RTT) of 25.5ms, proving it meets soft real-time control requirements. Notably, comparative analysis with an ideal localhost environment (average RTT of 15.8ms) quantitatively isolated the pure network overhead to approximately 9.7ms, objectively demonstrating the structural efficiency of the proposed architecture compared to middleware-based systems. This research presents a concrete methodology and engineering benchmark data enabling the construction of practical digital twins without expensive solutions.

Distributed control architecture is based on sharing control and data between multiple nodes on a network Communication and task sharing can be distributed between multiple control computers. Although many communication protocols exist, such as TCP/IP and UDP, they do not have the determinism that realtime control demands. Fiber-optic reflective shared memory creates the opportunity for realtime distributed control. This architecture allows control and computational tasks to be divided between multiple systems and operate in a deterministic realtime environment. One such shared memory architecture is based on Curtiss-Wright ScramNET family of fiber-optic reflective memory. MTS has built seismic and structural control software and hardware capable of utilizing ScramNET shared memory, opening up infinite possibilities in research and new capabilities in Hybrid and Model-In-The-Loop control.

The control architectures of Chuan Suo (CS) deep submergence rescue vehicle are introduced. The hardware and software architectures are also discussed. The hardware part adopts a distributed control system composed of surface and underwater nodes. A computer is used as a surface control machine. Underwater equipment is based on a multi-board-embedded industrial computer with PC104 BUS, which contains IO, A/D, D/A, eight-channel serial, and power boards. The hardware and software parts complete data transmission through optical fibers. The software part involves an IPC of embedded Vxworks real-time operating system, upon which the operation of I/O, A/D, and D/A boards and serial ports is based on; this setup improves the real-time manipulation. The information flow is controlled by the software part, and the thrust distribution is introduced. A submergence vehicle heeling control method based on ballast water tank regulation is introduced to meet the special heeling requirements of the submergence rescue vehicle during docking. Finally, the feasibility and reliability of the entire system are verified by a pool test.

This paper describes the implementation of DCS communication network that provides high bandwidth and reliability. The network for DCS in this paper adopts the Reflective Memory (RM) architecture and Fast Ethernet physical media that have 100Mbps bandwidth. Also, this network uses Ring Enhancement Device (RED) which was invented to reduce the time delay of each node. The DCS network that is introduced in this paper is named as ERCNet(Ethernet based Real-time Control Network). This paper describes the architecture and working algorithms of ERCNet and performs numerical analysis. In addition, the performance of ERCNet is evaluated by experiment using the developed ERCNet network.

The distributed digital control system has many shared common components, and a single fault in the system may have effects on not a single function. Not as in an analog system, the faults in a digital system usually make discrete and abrupt changes in its output, which are hard to be expected. To cope with these situations, the fault-tolerance is an inevitable property of a distributed control system. A distributed digital control system consists of many equipments, and each equipment can be implemented by many different technologies. The fault-tolerance has to be implemented depend-ing on the overall architecture and how each equipment is implemented. The paper analyzes and compares the strategies and tactics to add the fault-tolerances in a distributed digital control system, and studies how they can be combined appropriately.

$\textbullet$ Introduction $\textbullet$ System hardware base $\textbullet$ System software implementation $\textbullet$ Connect robotic systems to Internet $\textbullet$ Conclusions

The advance of computer, network, and Internet technology enables the control systems to process the massive data in the distributed computing environments. To implement and maintain the software in distributed environment, the component-based methodology is widely used. This paper proposes the middleware architecture for the distributed computer control system. With the proposed middleware services, it is relatively easy to maintain compatibility between products and to implement a portable control application. To achieve the compatibility between heterogeneous systems, the proposed architecture provides the communication protocols based on the XML with lightweight event-based service.

인간과 함께 협력하는 서어비스 산업에서 요구되는 로봇은 고정된 환경에서 단순 반복 작업을 하는 기존 산업용 로봇의 개념을 뛰어 넘어 변화하는 환경에서 이동하면서 물체 이송 및 조작 기능을 수행하는 작업 형태를 취한다. 일반적으로 서어비스 로봇은 이동 능력과 조작능력이 겸비된 mobile manipulator의 외양을 갖는 것이 가장 응용 분야가 넓다. 이러한 mobile manipulator는 구동 축만 10축 내외가 되므로 축별 서보 제어기와 종류별 센서 제어기들을 분산화 시키는 구조가 신뢰성, 연산 능력의 측면에서 바람직하다. 개방형 구조로써 서보 제어기와 센서 제어기의 결합에 따른 비용 절감을 위하여 저가의 고속 통신망을 사용하고, 제어기 구성 요소들의 수급 다양화와 보수 유지의 간편화를 위하여 개방화된 인터페이스 하드웨어를 채택한다. 또한 자체 동력원에 의해 구동되는 것이 작업범위에 제한을 가하지 않으므로 로봇 제어기가 로봇 내부에 실장되어 오랜 시간 운용 가능하도록 소형화된 구조를 지니도록 설계한다.

This paper presents the concepts developed to propose Distributed Control System(DCS). To achieve adequate satisfaction under various conditions, the DCS should be designed from two points of view of functions distributions and performance planning. Performance evaluation criteria can be specified by the response time between units and the utilization of each unit. One has to also consider the ease and the cost of installation, maintenance, repair. Based on these characteristics, different system configuration can be evaluated and compared through results about evaluation criteria in order lo select the best DCS for particular process. The results, in abbreviated form, of the simulation DCS controlling a CAL(Continuos Annealing Line) plant of iron process ate presented.

This paper introduces a case of SCADA System replacing from centralized processing system to distributed/open architecture system. The cons and pros of the distinctive two system configurations were studied and the requirements of new system that would be enable to easily follow 21 century's technical and operational inovation were presented.

최근 다양한 멀티미디어 서비스와 스트림 서비스의 급증과 사용자의 서비스 기대 증가로 인해 기존의 컴퓨팅 환경도 인터넷 기반의 분산 멀티미디어 환경으로 변화되고 있다. 이러한 다양한 요구를 만족시키기 위해서는 인터넷 환경과 실시간 특성들이 혼합된 폭넓은 범위의 분산 애플리케이션을 지원해야 하고, 이들 서비스간의 QoS(Quality of Service)를 보장해야 한다. 이를 위해 본 논문에서는 분산환경인 CORBA기반에서 자원들의 효과적인 관리와 서비스들간의 QoS를 보장하는 분산 QoS 관리 구조를 제시한다 즉, 클라이언트 측에 QoS 제어 관리 모들(QoS Control Management Module)을, 서버측에는 QoS 관리 모듈(QoS Management Module)을 각각 분산시켜 QoS 관리 및 제어를 분산 구조화함으로써 서버 시스템의 부하를 줄이고, 분산 서비스 응용에 지원을 확장할 수 있도록 하며 모듈들의 재사용이 가능하도록 하였다. 또한 분산 QoS 제어를 위해 실시간 협약(Negotiation) 및 동적 적응(Dynamic Adaptation)과정이 분산환경에서 수행되도록 기능 설계를 하였다. 이들 기능수행의 전반과정을 UML(Unified Modeling Lang uage)을 이용하여 순차적 다이어그램으로 기술하였다.

본 논문에서는 확장 미디어 제어 채널을 사용하여 시스템의 부하를 효율적으로 분산 처리 할 수 있는 다중 서버구조의 분산 인스턴트 메시지 시스템을 제안하였다. 미디어 제어 채널은 실시간 전송 분야에서 SIP 서버와 클라이언트 사이의 신뢰성 있는 제어 채널 설정 및 유지 기능을 제공한다. 본 연구에서는 이 미디어 제어 채널의 기능을 확장하여 멀티미디어 데이터를 포함한 다량의 인스턴트 메시지를 효율적으로 다중 서버에 분산 처리 할 수 있는 새로운 구조의 인스턴트 메시지 시스템을 제안하였다. 이를 위하여 본 연구에서는 사용자 수의 증가에 따라 복수 개의 서버에게 동적으로 부하를 분산 처리하기 위한 미디어 제어 채널 메시지가 설계되었고 서버들 사이에서 미디어 제어 채널 메시지의 교환 절차가 제시되었다. 제안된 시스템의 성능은 시뮬레이션을 통하여 분석하였다.

In this paper, a distributed instant message system with multiple servers architecture which can distribute system load effectively using an extended media control channel has been presented. A media control channel provides establishing a reliable control channel and also keeping a reliable control channel between SIP server and client in the field of real-time media transport area. In this study, a new instant message system architecture which can distribute massive instant message including multimedia data to multiple servers has been presented. The presented instant message system architecture can distribute system load by extending media control channel. For this purpose, media control channel messages, which distribute system load to multiple servers dynamically according to increasing number of users, have been designed in our presented system. And, in our research, an exchanging procedures of media control channel messages between servers have also been presented. The performance of the proposed system has been analysed by simulation.