• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.137.1-137
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• 2001

A new method for a guide robot using Real-Time Linux OS is introduced in this paper. A guide robot is to guide people in museums or buildings. So it has to be more reliable and stable in its control system. In addition, it has to satisfy Real-Time operation requirement because it needs to react to changing environment prompty. The task includes localization, map building, collision avoidance, path planning, and user interface software. The modular guide robot is designed with Real-Time Linux OS, which is composed of many open sources for scheduler, interrupt dispatcher, fifos, shared memory, timer services. We developed application software to satisfy the given task. The developed guide robot moves at 0.2ms and the interrupt latency is less than 100$\mu\textrm{s}$ It is thought that the developed system can be a stable and low cost open architecture robot controller for ...

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.8
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• pp.1820-1831
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• 2011

When both types of periodic and aperiodic tasks are required to run on a sensor node platform with limited energy resources, we propose an energy-efficient hybrid task scheduling technique that guarantees the deadlines of real-time tasks and provides non-real-time tasks with good average response time. The proposed hybrid task scheduling technique achieved better performance than existing EDF-based DVS scheduling techniques available in the literature, the FIFO-based TinyOS scheduling technique, and the task-clustering based non-preemptive real-time scheduling technique.

• IEMEK Journal of Embedded Systems and Applications
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• v.5 no.2
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• pp.103-110
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• 2010

Due to the increasing amount of electronic control system in a vehicle, the automotive software is increasingly sophisticated and complicated. Therefore it may be faced a time critical problem caused by its complexity. In order to solve such problems, the automotive electronic system can use a real-time scheduling mechanism based on predictability. We first consider the standard specification of the AUTOSAR OS and uC/OS-II such as its scheduling theory with time determinism. In this paper, we propose the scheduling algorithm to be conformable to a conformance class of OSEK/VDX specification. Algorithm analysis shows that our scheduling algorithm outperforms an existing Trampoline OS by intuition.

• Journal of Korea Multimedia Society
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• v.5 no.3
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• pp.323-330
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• 2002

Recently, the existing embedded real-time operating systems(RTOSs) are being developed in terms of various modified versions in every application fields. Major characteristics and difference of these OSs lie in their distinct development of mechanisms which can be used in various environment and task-scheduling function which can control time-limited contingencies. In this paper, we design and implement round/robin scheduling algorithm based on time-sharing with equal-priority for multiple tasks which are provided preemptive and priority task allocation function in $\mu{C/OS-II}$ version 2.03. We propose the most important event-ready list structure in $\mu{C/OS-II}$; kernel, and provide the running result for multiple tasks with equal priority for the proposed structure.

• Journal of the Korea Society of Computer and Information
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• v.24 no.11
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• pp.21-27
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• 2019

Recently, embedded systems have been introduced in various fields such as smart factories, industrial drones, and medical robots. Since sensor data collection and IoT functions for machine learning and big data processing are essential in embedded systems, it is essential to port the operating system that is suitable for the function requirements. However, in embedded systems, it is necessary to separate the hard real-time system, which must process within a fixed time according to service characteristics, and the flexible real-time system, which is more flexible in processing time. It is difficult to port the operating system to a low-performance embedded device such as 8BIT MCU to perform simultaneous real-time. When porting a real-time OS (RTOS) to a low-specification MCU and performing a number of tasks, the performance of the real-time and general processing greatly deteriorates, causing a problem of re-designing the hardware and software if a hard real-time system is required for an operating system ported to a low-performance MCU such as an 8BIT MCU. Research on the technology that can process real-time processing system requirements on RTOS (ported in low-performance MCU) is needed.

• The KIPS Transactions:PartA
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• v.16A no.6
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• pp.463-472
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• 2009

Real-time operating systems must have satisfying various conditions such as effective scheduling policies, minimized interrupt delay, resolved priority inversion problems, and its applications to be completed within desired deadline. The real-time operating systems, therefore, should be designed and developed to be optimal for these requirements. MicroC/OS-II, a kind of Real-time operating systems, uses the basic priority inheritance with a mutex to solve priority inversion problems. For the implementation of mutex, the kernel in an operating system should provide supports for numerous tasks with same priority. However, MicroC/OS-II does not provide this support for the numerous tasks of same priority. To solve this problem, MicroC/OS-II cannot but using priority reservation, which leads to the waste of unnecessary resources. In this study, we have dealt with new design a protocol, so called TPSP(Temporary Priority Swap Protocol), by an effective solution for above-mentioned problem, eventually enabling embedded systems with constrained resources environments to run applications.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.1
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• pp.166-171
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• 2003

This paper presents the algorithms and Matlab Toolbox for co-simulation of distributed real-time control system based on OSEK-OS and CAN protocol. This toolbox enables the developers to analyze the timing uncertainty, which is caused by resource sharing including shared memories and networks, and to take the timing uncertainty into consideration in the early design phase. Furthermore, this toolbox helps the developers to model the behaviors of a control system by providing graphical user interface for objects of OSEK-OS and CAN. To prove the feasibility of this toolbox, a vehicle body network system is modeled with this toolbox, and the timing uncertainties are analyzed.

• Journal of IKEEE
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• v.2 no.2 s.3
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• pp.270-277
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• 1998

As the network technologies advance, the control systems progress from a centralized architecture to a distributed one. However, these control systems were designed mostly based on the general-purpose operating systems(OS) and have many problems for assurance of a real-time property required for plant processing fields. Therefore, the control systems far a plant process upon real-time OS hare been increased gradually. In this paper, the real-time OS emphasizes on the realization of real-time processing capability, reliability of real-time response, and multi-processing functionality which are prerequisites for a distributed control system. And on the basis of this OS, the number of executable loop and logic, the functions of main plant processing, was analyzed and its validity was also evaluated. The system in this paper was designed not to effect on processing data while online, and the time spent on switching was measured.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11a
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• pp.505-508
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• 2002

본 논문은 Real-Time Linux를 기반으로 하는 개방형 로봇 제어기에 관한 내용이다. 여기서 Real-Time OS는 시스템의 수행결과가 기능적으로 정확해야 할 뿐만 아니라, 결과가 도출되는 시간 역시 주어진 제약 조건을 만족시켜야 하는 시스템이 이다. 이러한 특징 때문에 RTOS(Real-Time OS)는 항공, 전자, 기계분야뿐만 아니라 네트워크 분야에서도 많이 적용되어지고 있다. 본 논문에서는 Open Source를 지향하고 있는 범용의 Linux를 기반으로 하는 Real-Time Linux를 이용하여 로봇을 제어하는 구현을 함으로서 Real-Time Linux의 제어분야에 적용가능성을 제시해 본다.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1976-1981
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• 2003

Except a desktop computer and workstation, an embedded system is a system containing microprocessors. While a desktop computer and a workstation are designed for a general purpose, an embedded system is designed for a dedicated purpose. Thus, an embedded system must meet some constraints such as low power consumption, low cost, small size, real-time, or user-defined ones. A simple and low cost embedded system may be able to be designed without using embedded operating systems (OS). However, considered design time and effort, some embedded system had better be designed with using embedded OS. Under given constraints and purpose of some embedded systems, one embedded OS can save more time, cost, and effort in designing those embedded systems than others. This paper compares four embedded OSs, Windows CE, Embedded Linux, pSOS, and uC/OS. It analyzes several issues of embedded OS such as process scheduling, inter-process communication (IPC), memory management, and network support. Also, it describes the product of each embedded OS.