• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.1840-1845
• /
• 2005

The SoC and digital technology development recently enabled the emergence of information devices and control devices because the SoC present many advantages such as lower power consumption, greater reliability, and lower cost. It is required to use an embedded operating system for building control systems. So far, the Real-Time operating system is widely used to implement a Real-Time system since it meets developer's requirements. However, Real-Time operating systems reveal a lack of standards, expensive development, and license costs. Embedded Linux is able to overcome these disadvantages. In this paper, the implementation of control system platform using Real-Time Embedded Linux is described. As a control system platform, we use XScale of a Soc and build Real-Time control platform using RTAI and Real-Time device driver. Finally, we address the feasibility study of the Real-Time Embedded Linux as a Real-Time operating system for mobile robots.

• 제어로봇시스템학회논문지
• /
• 제12권2호
• /
• pp.194-200
• /
• 2006

The SoC and digital technology development recently enabled the emergence of information devices and control devices because the SoC presents many advantages such like lower power consumption, greater reliability, and lower cost. However, it is nearly impossible to use the SoC without operating systems because the SoC is included with many peripherals and complex architecture. It is required to use embedded operating systems and real-time operating systems may be used as an embedded operating system. So far, real-time operating systems are widely used to implement a Real-Time system since it meets developer's requirements. However, real-time operating systems have disadvantages including a lack of standards, expensive development, and license. Embedded Linux is able to overcome their disadvantages. In this paper, the implementation of control system platform for a mobile robot using real-time Embedded Linux is described. As a control hardware system platform, XScale board is used. As the real-time Embedded Linux, RTAI is adopted which is open source and royalty free, and supports various architectures and real-time devices, such like real-time CAN and real-time COM. This paper shows the implementation of RTAI on XScale board that means the porting procedure. We also applied the control system platform to the mobile robot and compared the Real-Time serial driver with non real-time serial driver. Experimental results show that that using RTAI is useful to build real-time control system with powerful functionalities of Linux.

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

• 제어로봇시스템학회논문지
• /
• 제18권4호
• /
• pp.337-342
• /
• 2012

This paper presents performance evaluation of real-time mechanisms for real-time embedded linux. First, we presents process for implementing open-source real-time embedded linux namely RTAI and Xenomai. These are real-time extensions to linux kernel and we implemented real-time embedded linux over the latest linux kernel. Measurements of executions of real-time mechanisms for each distribution are performed to give a quantitative comparison. Performance evaluations are conducted in kernel space about repeatability of periodic task, response time of Semaphore, FIFO, Mailbox and Message queue in terms of inter-task communication for each distribution. These rules can be helpful for deciding which real-time linux extension should be used with respect to the requirements of the real-time applications.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
• /
• pp.223-223
• /
• 2000

Embedded system area has brought an innovation and has been spread rapidly by the growth of the Internet, wireless telephony and multimedia recently. Many embedded systems are required to be real-time systems in that it needs multi-tasking and priority based scheduling. This paper introduces a real-time system that was developed with web server ability for control and monitoring system employing a real-time operating system. It discusses the design model, structure, and applications of web server system. We used SNDS100 board which has a 32-bit RISC microcontroller of ARM7TDMI core as a hardware platform. MicroC/OS kernel was used as Real-time operating system that supports a preemptive and multitasking functions. We developed a hierarhchical control and monitoring system that not only reduced system and management costs, but also enhanced reusability and portability.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2004년도 ICCAS
• /
• pp.1655-1658
• /
• 2004

In this paper, we design and implement remote servo motor control system with real-time micro embedded operating system. The system, where controller and camera image grabber are mounted, handles control commands transmitted from a remote PC web browser. A hard real-time servo motor driver running on the real-time micro embedded OS and then a digital control application which confirms precise sampling time intervals is constructed. Frame grabber images transmitted from camera are saved in a image data format to view on remote PC web browser.

• 대한임베디드공학회논문지
• /
• 제17권6호
• /
• pp.355-365
• /
• 2022

This paper addresses the problem of real-time tracking a high-speed ballistic target. Particle filters can be considered to overcome the nonlinearity in motion and measurement models in the ballistic target. However, it is difficult to apply particle filters to real-time systems because particle filters generally require much computation time. This paper proposes an accelerated particle filter using graphics processing unit (GPU) for real-time ballistic target tracking. The real-time performance of the proposed method was tested and analyzed on a widely-used embedded system. The comparison results with the conventional particle filter on CPU (central processing unit) showed that the proposed method improved the real-time performance by reducing computation time significantly.

• 대한임베디드공학회논문지
• /
• 제12권4호
• /
• pp.239-246
• /
• 2017

Time synchronization between distributed embedded systems in the Real Time Locating System (RTLS) based on Time Difference of Arrival (TDOA) is one of the most important factors to consider in system design. Clock jitter error between each system causes many difficulties in maintaining such a time synchronization. In this paper, we implemented a system to synchronize clocks between FPGA based distributed embedded systems using the recovery clock of CDR (clock data recovery) used in high speed serial communication to solve the clock jitter error problem. It is experimentally confirmed that the cumulative time error that occurs when the synchronization is not performed through the synchronization logic using the CDR recovery clock can be completely eliminated.

• 대한임베디드공학회논문지
• /
• 제5권1호
• /
• pp.18-22
• /
• 2010

In real-time embedded systems, the responsibility is the most important thing because it is related to human life. Context switching is a part of which can slow down the responsibility. We therefore should minimize the amount of state that needs to be saved during context switching. In this paper, we introduce a new architecture (Register Farm) for context switching which can exchange two contexts in one cycle time. Although it might increase the cost of MCU design and the complexity of circuit, it cannot miss any interrupt during context switching. Consequently, Register Farm architecture can make embedded systems spread out in human life because it can increase reliability and responsibility in real time embedded systems.

• 한국정보과학회논문지:시스템및이론
• /
• 제27권3호
• /
• pp.300-312
• /
• 2000

내장 실시간 시스템은 그 응용 분야가 매우 다양하며 그에 따라 실시간 처리와 신뢰도 보장에 대한 요구 또한 다양하다. 이러한 내장 실시간 시스템의 효율적인 개발과 실시간성 및 신뢰도 보장을 위해서는 적절한 실시간 모델이 필요하다. 최근 들어 객체지향 모델과 실시간 시스템을 접목시키는 실시간 객체 모델에 대한 연구가 활발하다. 본 논문에서 제안하는 dRTO (dependable Real-Time Object) 모델은 내장 실시간 시스템의 다양한 요구사항을 지원할 수 있도록 객체지향 개념, 실시간 개념, 신뢰성 개념 등을 단일 모델에 수용한다. 그리고 이 3 가지 기본 개념을 지원하기 위해서 5 가지 원시 클래스를 제공한다. dRTO 모델의 특징은 다음과 같다. 첫째, 객체의 시간 제약사항은 물론 객체 간의 상호작용과 관련된 시간 제약을 효율적으로 모델링하고 구현할 수 있도록 해준다. 둘째, 내장 시스템을 구성하는 하드웨어, 응용 소프트웨어, 커널 등을 하나의 틀 안에서 모델링할 수 있다. 셋째, 결함 감지 및 처리에 관해 명시적으로 표현할 수 있다.