• 제어로봇시스템학회논문지
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• 제14권11호
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• pp.1117-1123
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• 2008

This paper implements dual-kernel system using standard Linux and real-time embedded Linux for the real-time control of intelligent robot systems. Such system provides more useful services including standard Linux thread that is easy to implement complicated tasks and real-time tasks for the deterministic response to velocity control. Here, an open source real-time embedded Linux, XENOMAI, is ported on embedded target board. And for interfacing with motor controller we adopted a real-time serial device driver. The real-time task was implemented with a priority to keep the cyclic control command for trajectory control. In order to validate deterministic response of the proposed system, the performance measurement of the delay in performing trajectory control with feedback loop is evaluated with non real-time standard Linux. The proposed software architecture is anticipated to take advantage of features in both standard Linux and real-time operating systems for the intelligent robot systems.

• 항공우주기술
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• 제12권2호
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• pp.173-179
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• 2013

본 논문에서는 한국형발사체 탑재장비 시뮬레이터의 개발을 위해 설계하고 구축한 테스트베드에 대해 기술한다. 시뮬레이터 테스트베드는 범용성 및 확장성을 위해 CPCI 기반 산업용 하드웨어 시스템을 활용하여 설계하였고, 높은 시스템 안정성 제공 및 실시간 모사 기능 처리를 위해 실시간 운영체제인 QNX를 탑재하였다. 또한 나로호의 탑재장비 중 PDU의 기능을 모사하는 QNX용 실시간 모사 프로그램을 개발하였고, 나로호 상단부 점검장비와의 인터페이스 시험을 통해 시뮬레이터 테스트베드의 기능을 점검하였다. 구축된 시뮬레이터 테스트베드는 향후 실제 한국형발사체 탑재장비 시뮬레이터의 설계 및 개발 단계에서 개발 실현가능성 검증에 활용될 것이다.

• 로봇학회논문지
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• 제7권4호
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• pp.292-298
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• 2012

It is a real-time system that the system correctness depends not only on the correctness of the logical result of the computation but also on the result delivery time. Real-time Operating System (RTOS) is a software that manages the time of a microprocessor to ensure that the most important code runs first so that it is a good building block to design the real-time system. The real-time performance is achieved by using real-time mechanisms through data communication and synchronization of inter-task communication (ITC) between tasks. Therefore, test on the response time of real-time mechanisms is a good measure to predict the performance of real-time systems. This paper aims to analysis the response characteristics of real-time mechanisms in kernel space for real-time embedded Linux: RTAI and Xenomai. The performance evaluations of real-time mechanism depending on the changes of task periods are conducted. Test metrics are jitter of periodic tasks and response time of real-time mechanisms including semaphore, real-time FIFO, Mailbox and Message queue. The periodicity of tasks is relatively consistent for Xenomai but RTAI reveals smaller jitter as an average result. As for real-time mechanisms, semaphore and message transfer mechanism of Xenomai has a superior response to estimate deterministic real-time task execution. But real-time FIFO in RTAI shows faster response. The results are promising to estimate deterministic real-time task execution in implementing real-time systems using real-time embedded Linux.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.198-203
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• 2004

This paper describes a real-time control architecture for DUSAUV (Dual Use Semi-Autonomous Underwater Vehicle), which has been developed at Korea Research Institute of Ships & Ocean Engineering (KRISO), KORDI, for being a test-bed oj development of technologies for underwater navigation and manipulator operation. DUSAUV has three built-in computers, seven thrusters for 6 degree of freedom motion control, one 4-function electric manipulator, one pan/tilt unit for camera, one ballasting motor, built-in power source, and various sensors such as IMU, DVL, sonar, and so on. A supervisor control system for GUI and manipulator operation is mounted on the surface vessel and communicates with vehicle through a fiber optic link. Furthermore, QNX, one of real-time operating system, is ported on the built-in control and navigation computers of vehicle for real-time control purpose, while MicroSoft OS product is ported on the supervisor system for GUI programming convenience. A hierarchical control architecture which consist of three layers (application layer, real-time layer, and physical layer) has been developed for efficient control system of above complex underwater robotic system. The experimental results with implementation of the layered control architecture for various motion control of DUSAUV in a basin of KRISO is also provided.

• 한국정보통신학회논문지
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• 제6권2호
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• pp.159-168
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• 2002

실시간 객체지향 분산 컴퓨팅은 객체 네트워크 형태에서 분산된 컴퓨터 시스템 구조와 관련 된 실시간 분산 컴퓨팅의 한가지 형태이다. 최근에 실시간 응용분야에 적합한 기존의 객체지향 시스템 구조를 확장한 몇 가지 의 구조가 제안되었다. 실시간 시뮬레이션 프로그램의 하나인 시간 및 메시지 트리거 객체지향 프로그램밍이 분산된 시간 트리거 시뮬레이션으로 설계될 수 있으며, 일반적이고 보편적인 설계 타입으로서 사용되고, 하나 의 실시간 시뮬레이션 패러다임으로 제안하였다. 실시간 객체지향 프로그램밍은 안전을 중요시하게 여기는 응용분야에 적용할 수 있으며, 실시간 운영체제 시스템 커널로서 객체지향 프로그램밍 언어인 비쥬얼 C++언어로 작성되었다. 응용 시스템에서 실시간 서비스를 보장하기 위한 설계자들의 노력을 현저하게 줄일 수 있는 장점을 가지고 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.71-74
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• 1996

The concept of uniformity in control implementation is exploded for improving efficiency of design procedure. A controller area operating system which includes real time kernel and control specific shell are developed. Three examples are discussed for the validation of tile system.

• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 1997년도 추계학술대회 발표논문집:21세기를 향한 정보통신 기술의 전망
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• pp.417-433
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• 1997

A real-time operating system has focused primary on techniques to minimize processing time, with a secondary emphasis on system reliability issues. Conversely, fault-tolerant system has concentrated on using recourse and information redundancy to maximize the availability and reliability of the system, with a lesser emphasis on performance. We have developed a fault-tolerant and real-time operations system which support a powerful concurrent runtime environment under the above requirements. In this paper, we present an overview of real-time systems, design and implementation of a duplex architecture using advanced concepts and technologies such as fast " fault detection", "fault isolation" and "fault recovery" Because the duplex architecture has two dentical hardware elements and has several recovery steps and hierarchy to facilitate a fast recovery which must be proceeded by a prompt fault detection and isolation. Thus it makes possible to minimize the overhead of the systems including hardware and software and guarantee the service continuity of he systems.

• 한국국방경영분석학회지
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• 제25권1호
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• pp.199-214
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• 1999

The Constructive Battle Simulation Model is very important to the recent military training for the substitution of the field training. However, real battlefield systems operate under real-time conditions, they are inherently distributed, concurrent and dynamic. In order to reflect these properties by the computer-based simulation systems which represent real world processes, we have been developing constructive simulation model for several years. Conventionally, scheduling and resource allocation activities which have timing constraints, we elaborated on these issues and developed the simulation system on commercially available hardware and operating system with lock-free resource allocation scheme and rate monotonic scheduling.

• 대한기계학회논문집A
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• 제30권11호
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• pp.1348-1357
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• 2006

In a hybrid three-layer control architecture(deliberative, sequencing, and reflexive), the lowest reflexive layer consists of resources, actions, an action coordinator, and motion controllers. Because the execution of individual components in the reflexive layer should be done in real-time, each component has to be simple and, due to this reason, the Linux-RTAI(Real-Time Application Interface for Linux) has been used as an operating system. In this paper, a navigation control architecture, which combines the components in the reflexive layer and the navigation-related modules in the sequencing layer, is proposed. And then, as basic components, four actions(Goto, Avoid, Move, and EmergencyStop) are designed. Experimental results confirm the effectiveness of the proposed architecture and the performance of individual associated actions.

• 항공우주시스템공학회지
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• 제1권1호
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• pp.60-66
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• 2007

The importance of software development in the integration of an avionics system is continuously increasing. And we can expect enlarged soft ware portion in the system integration for the more intelligent, reliable, and automated avionics system. For an avionics system software development the selection of a real-time operating system and internal avionics data bus protocol is very important from the viewpoint of the integration with the system hardware. In this paper, we present current trend of an avionics system software development including software development methodology, software development process, and international software process assessment improvement model.