• Journal of Institute of Control, Robotics and Systems
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• v.14 no.11
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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.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1840-1845
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• 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.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.2
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• pp.194-200
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• 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.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.11-14
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• 2007

The Embedded Linux System has been developed as a system which can be used with a processor of low efficiency and small-sized memory. Unlike the usual Linux and Windows web server, it has some limitations in the install of application programs, compatibility and scalability when transferring data through web server in real-time. In this paper, we present a real-time remote monitoring system which is very useful to the embedded linux system. The presented system use Java Script without the additional programs at the Embedded Linux System web server and confirm the efficiency of the system through the existing real-time remote monitoring techniques.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.10
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• pp.789-797
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• 2003

An implementation scheme and some improvements are proposed to adopt public-licensed operating system, Linux and de-facto world-wide network standard, TCP/IP into the field of behavior-based autonomous mobile robots. To demonstrate the needs of scheme and the improvement, an analysis is performed on a server/client communication problem with real time Linux previously proposed, and another analysis is also performed on interactions among TCP/IP communications and the performance of Linux system using them. Implementation of behavior-based control architecture on real time Linux is proposed firstly. Revised task-scheduling schemes are proposed that can enhance the performance of server/client communication among local tasks on a Linux platform. A new method of TCP/IP packet flow handling is proposed that prioritizes TCP/IP software interrupts with aperiodic server mechanism as well. To evaluate the implementation scheme and the proposed improvements, performance enhancements are shown through some simulations.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.184-186
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• 2007

Currently many sensors and processing data in a robot based on USN environments need to real-time features. In this paper, we examine recent research trends on real-time operating systems, especially on real-time embedded Linux, RTAI and Xenomai, for intelligent robots. Xenomai is a real-time development framework and have special feature supporting RTAI, VxWorks, pSOS+ etc. through the "skin". This research gives a guide to researcher in using real-time embedded Linux in the sense of architecture, supporting real-time mechanisms, kinds of real-time device driver, performances.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.770-774
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• 2002

Recently, most of the embedded system have the function of multimedia information processing and network connecting. This make the overall system more complicated and need a new approach. Moreover the embedded system must be real-time system, which are different with Linux is constructed and the kernel is redesigned on the strong-arm board in order to make the real-time embedded web-server system.

• The Journal of the Korea Contents Association
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• v.11 no.9
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• pp.45-53
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• 2011

According to the necessity of measuring equipments for advanced military systems, real-time characteristics such as time determinism and execution accuracy pursuing low-latencies have become very important. With this reason, the market demand for real-time features in the general purpose operating system such as Linux has been enlarging. To meet these requirements, RTLinux and RTAI has been developed as dual-kernels based on Linux. However, developers should use assembler languages to facilitate real-time in RT-Linux, it is very difficult to deal with it. RTAI has disadvantage that it only provides soft real-time. To solve these problems, RTiK-Linux was developed. In this paper, we propose a new dual-kernel with hard real-time capabilities in Linux, called RTiK-Linux(Real-Time implemented Kernel for Linux). We first introduce related researches and then describe the design methodologies to guarantee the resolution which almost accords with the timer settings. Finally, we present the results of experimental measurements and analyze them in order to validate and evaluate the proposed RTiK-Linux.

• ETRI Journal
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• v.29 no.3
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• pp.270-280
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• 2007

In Linux, real-time tasks are supported by separating real-time task priorities from non-real-time task priorities. However, this separation of priority ranges may not be effective when real-time tasks make the system calls that are taken care of by the kernel threads. Thus, Linux is considered a soft real-time system. Moreover, kernel threads are configured to have static priorities for throughputs. The static assignment of priorities to kernel threads causes trouble for real-time tasks when real-time tasks require kernel threads to be invoked to handle the system calls because kernel threads do not discriminate between real-time and non-real-time tasks. We present a dynamic kernel thread scheduling mechanism with weighted average priority inheritance protocol (PIP), a variation of the PIP. The scheduling algorithm assigns proper priorities to kernel threads at runtime by monitoring the activities of user-level real-time tasks. Experimental results show that the algorithms can greatly improve the unexpected execution latency of real-time tasks.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.709-712
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• 2003

In this research, we port the RT-Linux to MVME 5100 board which is driven by VxWorks or Vertex until now. And, we developed the data logging modules by using the RT-Linux. This module gathers two different scan timing data from plant and sends this data to the host controller with real time.