• 대한의용생체공학회:의공학회지
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• 제29권1호
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• pp.32-39
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• 2008

This paper reports on a realtime OS based master-slave configuration robot control system for laparoscopic surgery robot which enables telesurgery and overcomes shortcomings with conventional laparoscopic surgery. Surgery robot system requires control system that can process large volume information such as medical image data and video signal from endoscope in real-time manner, as well as precisely control the robot with high reliability. To meet the complex requirements, the use of high-level real-time OS (Operating System) in surgery robot controller is a must, which is as common as in many of modem robot controllers that adopt real-time OS as a base system software on which specific functional modules are implemened for more reliable and stable system. The control system consists of joint controllers, host controllers, and user interface units. The robot features a compact slave robot with 5 DOF (Degree-Of-Freedom) expanding the workspace of each tool and increasing the number of tools operating simultaneously. Each master, slave and Gill (Graphical User Interface) host runs a dedicated RTOS (Real-time OS), RTLinux-Pro (FSMLabs Inc., U.S.A.) on which functional modules such as motion control, communication, video signal integration and etc, are implemented, and all the hosts are in a gigabit Ethernet network for inter-host communication. Each master and slave controller set has a dedicated CAN (Controller Area Network) channel for control and monitoring signal communication with the joint controllers. Total 4 pairs of the master/slave manipulators as current are controlled by one host controller. The system showed satisfactory performance in both position control precision and master-slave motion synchronization in both bench test and animal experiment, and is now under further development for better safety and control fidelity for clinically applicable prototype.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1897-1900
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• 2004

In recent years, a lot of industrial equipments have serial communication channel such as FieldBus (CAN, Profibus, etc.) or Ethernet that provides real time communication between industrial equipments. Theses applications include gantry crane, robot, chip mounter, etc.. In this paper, we discuss the synchronization technique for networked multi-motor systems where controllers (commercial servo amps) are distributed and interconnected by CAN (Controller Area Networks). We first describe the equivalent model for the individual servo-amp and motor using the frequency response. We design the $H{\infty}$ controller for motion synchronization. Finally, the synchronization technique using the equivalent model and the $H{\infty}$ controller is verified by the simulation and the experiment.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(1)
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• pp.275-278
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• 2000

Recently ATM(Asynchronous Transfer Mode) technology is facing challenges from Integrated Service IP(Internet Protocol), IP router, Gigabit Ethernet. Although ATM is approved by ITU-T as the standard technology in B-ISDN, its survival is still in question. In the ATM networks, the Guaranteed Frame Rate(GFR) service has been designed to accommodate non-real-time applications, such as TCP(Transmission Control Protocol)/IP based traffic. The GFR service not only guarantees a minimum throughput at the frame level, but also supports a fairshare of available resources. We have studied different discarding and scheduling schemes, and compared their throughput and fairness when TCP/IP Traffic is carried. Through simulations, we know that only per-VC queueing with weighted Round Robin(WRR) can guarantee Minimum Cell Rate Among all the Schemes that have been experimented, we recommend DT-EPD(Dynamic Threshold-Early Packet Discard) integrated with MCRplus(Minimum Cell Rate) to support the GFR service.

• 한국정보과학회논문지:시스템및이론
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• 제26권3호
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• pp.341-349
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• 1999

본 논문은 실시간 통신을 위한 이중 TDMA 구현 이더넷의 구조를 제시하고 이 네트워크 상에서의 대역폭 할당 기법을 제안 및 평가한다. 대역폭 할당 기법은 사전에 알려진 스트림 집합의 주가, 전송시간등의 실시간 트래픽 특성분석에 의해 프레임 시간의 범위, 사용율.종료시한.프로토콜 제약조건을 구하고 이를 만족시키는 프레임 시간과 슬롯시간을 결정한다. 이 기법은 단일 TDMA 구현 이더넷의 대역폭 할당에 따르는 낭비 시간 분석에 기반하고 있으며 이중화의 특성을 이용하여 낭비시간을 감소시킴으로써 단순히 대역폭이 두 배로 확장된 네트워크보다 높은 스케쥴 가능성을 보인다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1994년도 춘계학술대회
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• pp.49-52
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• 1994

We have developed a biological signal measurement, archiving, and communication system (SiMACS). The front end of the system is the intelligent data processing unit (IDPU) which includes ECG, EEG, EMG, blood pressure, respiration, temperature measurement modules, module control and data acquisition unit, real-time display and signal processing unit. IDPUS are connected to central data base unit through LAN(Ethernet). Workstations which receive signals from central DB and provide various signal analysis tools are also connected to the network. The developed PC-based SiMACS is described.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1424-1427
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• 1996

OTS(Operator Training System) requires computation for the systematic training in real-time. So we have developed a distributed operator training system that is composed of workstation based server and PC based user modules. Sever and OM(OTS Manager) modules are located in the workstation server and user modules are located in PCs. User modules have DCS-like user interfaces and transfer data with OM over the coaxial ethernet. This paper delineates a total system architecture and definition of data transferring between OM and User module. Having applied this system to a batch process, we could analyze operator's tasks.

• Journal of Information Technology Applications and Management
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• 제23권2호
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• pp.61-80
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• 2016

The wireless mesh network (WMN) is a next-generation technology for data networking that has the advantage in cost and the flexibility in its construction because of not requiring the infra-structure such as the ethernet. This paper focuses on the optimal link scheduling problem under the wireless mesh network to effectuate real-time streaming by using the constraint programming. In particular, Under the limitation of half-duplex transmission in wireless nodes, this paper proposes a solution method to minimize the makespan in scheduling packet transmission from wireless nodes to the gateway in a WMN with no packet transmission conflicts due to the half-duplex transmission. It discusses the conflicts in packet transmission and deduces the condition of feasible schedules, which defines the model for the constraint programming. Finally it comparatively shows and discusses the results using two constraint programming solvers, Gecode and the IBM ILOG CP solver.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.606-609
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• 2001

This paper's purpose is to obtain 3-Dimension information by using a monocular camera. This system embodies to obtain the height of object by using trigonometry method between a reference point of circumstance and an object. It is possible to build up system regardless of operating system, and then set it up. An comfortable USB port camera is used everywhere without the capture board. The internet can be used by using the applet and JMF everywhere. We regard the camera as a fixed. And we have developed a Real-Time JPEG/RTP Network Camera system using UDP/IP on Ethernet.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2774-2776
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• 2002

본 논문에서는 리플렉티브 메모리 방식의 산업용 통신망으로 개발된 ERCNet(Ethernet based Real-time Control Network)에 대해서 설명한다. ERCNet은 기존의 리플렉티브 메모리 방식의 네트워크에 비교하여 속도가 빠르고 데이터 처리량이 많다. ERCNet은 갈수록 데이터 양이 증가하고 있는 산업 환경에 적합하도록 만들어졌다. 본 논문에서는 ERCNet의 전체적인 구조와 성능향상을 위해 고안된 기기들에 대해서 설명하고, ERCNet의 성능 척도에 대해 수학적 분석을 행한다. 마지막으로 ERCNet 의 성능에 대한 수학적 분석 결과 수식에 대해 실험을 통해 정확성을 검증한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2469-2471
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• 2002

MMI 시스템은 제철 공정에서 발생되는 다양한 데이터를 조업자에게 쉽고 빠르게 전달하기 위해, real time operating system에서 동작하는 제철공정의 주된 제어 프로세스와 인터페이스 한다. 따라서 MMI 시스템은 제철 공정의 주된 제어 프로세스와 ethernet network을 통해 공유 데이터들을 통신하도록 개발되고, MMI 시스템은 M/S window operating system과 DDE(Dynamic Data Exchange) 라이브러리 환경을 기반으로 개발된다. 수 개의 MMI client PC와 1 개의 MMI server로 구성되는 MMI 시스템은 MMI client들 사이의 공유 데이터가 동기화될 수 있도록 최적 packet 양을 도출하고, 신뢰성 높은 데이터 전송을 위한 특별한 데이터 핸들링 방법을 사용한다. MMI 시스템은 GUI(Graphic User Interface)를 사용하여 조업자에게 친숙한 window 화면을 제공하므로, MMI 시스템의 화면 수정, 첨가 및 삭제가 비용 부담없이 용이하게 진행되므로, 기존 제철 공정에서 사용하던 OCP(Operating Control Panel)들이 MMI 시스템으로 대체되고 있다.