• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.97-100
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• 1997

Fieldbuses are used as the lowest level communication network for real-time communication in factory automation and process control systems. Data generated from field devices can be divided into three categories: sporadic real-time, periodic real-time and non real-time data. Since these data share one fieldbus network medium, it needs a method that allocate the limited bandwidth of fieldbus network to the sporadic real-time, periodic real-time and non real-time traffic. This paper introduces an implementation method of bandwidth allocation scheme introduced in [51 on PROFIBUS. Using the modified PROFIBUS FDL(Fieldbus Data Link layer), the bandwidth allocation scheme introduced in [51 is verified by the experiments.

• 로봇학회논문지
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• 제18권3호
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• pp.281-284
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• 2023

Real-time control communication network system is important for developing defense robots because it affects environmental interaction, performance, and safety. We propose a real-time control communication network using the Xenomai real-time operating system and the open-source EtherCAT master library, SOEM. EtherCAT is an Ethernet-based industrial communication method. It has low latency and many functions such as cable redundancy and distributed clock synchronization. We use Xenomai RTOS and Intel NUC to develop the system. Experimental tests demonstrate the Real-time EtherCAT master implementation, and communication with CiA301-based slave devices. The jitter measurement was conducted to validate the real-time performance of the system. The proposed system shows possibility for real-time robotics applications in various defense robots.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.32-32
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• 2000

We present CReMeS, a CORBA-compliant design and implementation of a new real-time communication service. It provide for of a new real-time communication service. It provide for efficient, predictable, and scalable communication between information producers and consumers. Experimental results demonstrate that CReMeS can achieve better performance, predictability and scalability than a Real-Time implementaion of the CORBA Event Service.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.350-353
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• 2004

The increasing use of Ethernet-TCP/IP network in industry has led to the growing interest in its reliability in real-time applications such as automated manufacturing systems and process control systems. However, stochastic behavior of its medium access scheme makes it inadequate for time-critical applications. In order to guarantee hard real-time communication service in Ethernet-TCP/IP network, we proposed an algorithm running over TCP/IP protocol stack without modification of protocols. In this paper, we consider communication services guaranteeing deadlines of periodic real-time messages over MAC protocols that have unbounded medium access time. We propose a centralized token scheduling scheme for multiple access networks. The token is used to allow a station to transmit its message during the time amount that is appended to the token. The real-time performance of the proposed algorithm has been described.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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• pp.151-154
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• 2003

In this paper, we described a method to guarantee a real-time communication in the hetegeneous network for the personal robot. The hetegeneous network is composed of many kinds of network like IEEE1394, Ethernet, CAN, Bluetooth, Wireless Lan and so on. real-time data is transfered via those kinds of network. Those network have different characteristics as speed, bandwidth, Priority. we used IEEE1394, Ethernet, CAN to study in this paper. To guarantee a real-time communication, a worst case response time must be scalable. In this environment to guarantee a real-time communication, we get a worst case response time of each network and a end-to-end worst case response time.

• 한국통신학회논문지
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• 제25권10B호
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• pp.1675-1689
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• 2000

We present CReMeS a CORBA-compliant design and implementation of a new real-time communication service. It provides for efficient predictable and scalable communication between information producers and consumers. The CReMeS architecture is based on MidART's Real-Time Channel-based Reflective Memory (RT-CRM) abstraction. This architecture supports the separation of QoS specification between producer and consumer of data and employs a user-level scheduling scheme for communicating real-time tasks. These help us achieve end-to-end predictability and allows our service to scale. The CReMeS architecture provides a CORBA interface to applications and demands no changes to the ORB layer and the language mapping layer. Thus it can run on non real-time Off-The-Shelf ORBs enables applications on these ORBs to have scalable and end-to-end predictable asynchronous communication facility. In addition an application designer can select whether to use an out-of-band channel or the ORB GIOP/IIOP for data communication. This permits a trade-off between performance predictability and reliability. Experimental results demonstrate that our architecture can achieve better performance and predictability than a real-time implementation of the CORBA Even Service when the out-of-band channel is employed for data communication it delivers better predictability with comparable performance when the ORB GIOP/IIOP is used.

• 전자공학회논문지A
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• 제31A권10호
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• pp.21-30
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• 1994

We discussed the Distributed Control System's design on preface and analyzed time of the real-time communication by using designed system. The DCS proposed in this thesis was implemented to network file system having recovery advantage and shared memory method to access file system of a Remote Station with ease. Also, this system minimized the network delay-time by using the real-time VME147 board. In implemented DCS, the performance analysis of real-time process of a Remote Station was done to get the total time for reak-tune communication from a Remote Station to the Central Station after terminating of process. For the analysis of system performance, we experiented by three steps. Firstly, we measuredthe processing the of LOOP function that real-time CPU convertes to-2,500~10.000 values from the input data of the Analog Interface Card. Secondly, we measured the processing time of the LOGIC function and the LOOP function. Lastly, we measured total processing time for communication from a Remote Station to the Centrol Station.

• 대한전기학회논문지:전력기술부문A
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• 제48권12호
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• pp.1580-1588
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• 1999

This paper evaluates the real-time performance of the Train Communication Network (TCN) that consists of WTB and MVB. A run-time scheduling algorithm for the hard-real time communication was proposed and its performance was evaluated. Also, a new addressing method and the adaptive tree algorithm were suggested to enhance performance. The overall performance was evaluated by computer simulation using Arena.

• 한국콘텐츠학회논문지
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• 제21권1호
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• pp.475-484
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• 2021

안드로이드 운영체제는 스마트폰 시장과 함께 빠르게 자리잡으며 네비게이션, 냉장고 패널 등 다양하게 적용하고 있다. 기존 단말은 정확한 수행 시간이 요구되는 RTOS를 사용하면서 높은 정밀도를 요구하는 서비스의 구현이 가능했으나, 안드로이드는 높은 정밀도의 실시간 성능을 제공할 수 없는 단점이 있다. 본 논문에서는 안드로이드 운영체제에서 동작하는 실시간 통신 방법을 제안한다. 실시간 통신은 UDP 프로토콜을 이용하여 부하를 줄이고, 커널 영역에 고정밀 타이머를 통해서 실시간 운영체제의 타임 틱을 구성한다. 안드로이드 응용 레벨의 라이브러리를 작성하여 실시간 통신을 구현하고 실시간 성능 검증을 위해 기존 안드로이드의 라이브러리와 비교하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.602-605
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• 2001

This paper focus on a method to use Ethernet Network for Industrial Communication Network. Ethernet use the CSMA/CD MAC(Medium Access Control) Protocol at the Data-Link Layer, Which isn't suit for Industrial Communication Network requiring Real-Time Communication, periodic data processing, critical data processing characteristics. In this paper we proposed the Virtual Polling Algorithm at the Application Layer will be solution of using the Ethernet Network for the Industrial Communication Network, Proposed Algorithm terminate the Collision in the network thus Delay Time is reduced and Real-Time Communication will be implemented.