• 제어로봇시스템학회논문지
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• 제3권4호
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• pp.373-380
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• 1997

In order to implement the real-time operating systems for robot controller, this paper proposes a systematic method for implementing the real-time kernel under the DOS environment. So far, we designed the robot control software and its own operating system simultaneously. Though robot operating systems have simple structure, it allows the developer to have a surplus time and effort to implement complete robot systems. In addition to this, in most cases of this type, operating systems does not support multitasking function, thus, low level hardware interrupts are used for real-time execution. Subsequently, some kinds of real-time tasks are hard to implement under this environment. Nowadays, the operating systems for robot controller requires multitasking functions, intertask communication and task synchronization mechanism, and rigorous real-time responsiveness. Thus, we propose an effective and low costs real-time systems for robot controller satisfying the various real-time characteristics. The proposed real-time systems are verified through real implementation.

• 한국콘텐츠학회논문지
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• 제17권10호
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• pp.587-597
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• 2017

최근 하드웨어의 발전으로 모바일 환경에서 리눅스나 안드로이드 같은 범용 운영체제 환경에서 실시간성의 요구가 증가하고 있으나, 범용운영체제의 경우 실시간성을 제공하지 못하는 단점이 있다. 이를 해결하기 위해 리눅스에 부가적으로 설계된 RTiK(Real-Time implanted Kernel)을 통해 실시간성을 제공할 수 있으나, 기존 RTiK의 경우 x86 아키텍처만을 제공하는 단점이 있으며, 실시간성 지원을 위해서는 CPU 플랫폼에 종속되는 한계가 있다. 본 논문에서는 CPU 플랫폼 이식을 위해 ARM 아키텍쳐를 위한 실시간 확장커널인 RTiKA(Real-Time implant Kernel for ARMLinux)을 설계 및 구현한다. 실시간성 제공을 위해 독립적인 Local APIC Timer를 대체하는 MCT 타이머를 이용하였으며, 성능 검증 및 평가를 위해 생성된 실시간 태스크의 주기를 측정하였고, 1ms 단위의 주기를 바탕으로 여러 개의 실시간 태스크에 대한 동작을 보장할 수 있었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.1181-1184
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• 2005

In this paper, we proposed small scale real-time operating system for embedded system. Real-time system is characterized by the severe consequences that result if logical as well as timing correctness properties of system are not met. On real-time system, real-time operating system allows real-time applications to be designed and expanded easily. Functions can be added without requiring major changes to the software. We design small scale real-time operating system for preemptive kernel, and design kernel component such as multitasking, scheduler, task priority, semaphore, inter-task communication, clock tick timer, ISR(Interrupt Service Routine) mechanism has low interrupt latency.

• 제어로봇시스템학회논문지
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• 제17권1호
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• pp.38-46
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• 2011

The OPRoS (Open Platform for Robotic Service) framework provides uniform operating environment for service robots. As an OPRoS-based service robot has to support real-time as well as non-real-time applications, application of Windows NT kernel based operating system can be restrictive. On the other hand, various benefits such as rich library and device support and abundant developer pool can be enjoyed when service robots are built on Windows NT. The paper presents a user-mode component scheduler of OPRoS, which can provide near real-time scheduling service on Windows NT based on the restricted real-time features of Windows NT kernel. The component scheduler thread with the highest real-time priority in Windows NT system acquires CPU control. And then the component scheduler suspends and resumes each periodic component executors based on its priority and precedence dependency so that the component executors are scheduled in the preemptive manner. We show experiment analysis on the performance limitations of the proposed scheduling technique. The analysis and experimental results show that the proposed scheduler guarantees highly reliable timing down to the resolution of 10ms.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.285-288
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• 1998

In this paper, we present mSROS(Micro-Scalable Realtime Operating System) to be applied commonly to the device controller systems in the HANbit ACE256 system. The device controller systems in HANbit ACE256 system are organized as many kinds of device controller. Applying modified PPOS(Peripheral Processor Operating System)which is an operating system for devices of the TDX-10 switching system to the firmwares for them, the inefficiency in development and maintenance exists inherently. To remove the inefficiency nd to improve the performqance of firmwares, we build a common operating system platform that including multi-tasking microkernel so that the firmwares among devices can acquire convenient development and cheap cost of maintencance. Especially, building a virtual machine as a development methodology, it is possible to remove dependency from the kernel so that any kinds of commercial real-time kernels can be used in mSROS as a basic kernel. The virtual machine in mSROS is compatible with the API of SROS(Scalable Realtime Operating System), PPOS, and CROS(Concurrent Realtime Operating System).

• 한국멀티미디어학회논문지
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• 제24권2호
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• pp.199-207
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• 2021

It is very important to support real-time on the inspection equipment based on Windows. In particular, in the system using MIL-STD-1553B communication, which is widely used in military weapon systems, real-time is required for inspection equipment that uses mostly platforms based on Windows such as Industrial PCs. However, in order to use a complete real-time operating system such as VxWorks, the purchase cost is expensive and the implementation is complicated on the system, so it is not suitable for inspection equipment that requires simple functions to just check go or no-go. Therefore, in this paper, a Real-Time implanted Kernel(RTiK) in the Windows kernel is implanted in order to improve these defects, and real-time performance is implemented for periodically MIL-STD-1553B communication by Deferred Procedure Call(DPC) of Windows. Also, it was verified that the period of up to 2ms was guaranteed with a RDTSC into the EDX:EAX registers for measuring the periodicity.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.347-351
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• 1991

We propose a real time kernel chimera implemented under AT&T UNIX motorola versoin, Carnegie Mellon Univ. in U.S first developed chimera using SUN Worstation with Berkley UNIX based on VMEbus. The major differences between Canegie Mellon's and ours are downloading program and communication method between host and target. Original chimera used device driver but we used UNIX system call corresponding to shared memory when user downloads program and communicates. We modified kernel itself because the two different UNIX have different link editor.

• 한국콘텐츠학회논문지
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• 제17권10호
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• pp.1-8
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• 2017

최근 군용장비의 첨단화가 가속됨에 따라 장비의 성능을 실시간으로 검증하는 점검장비 역할이 중요해지고 있다. 대부분 점검장비가 개발 편의성, 개발기간 등을 고려해서 윈도우 기반으로 개발되었다. 하지만 윈도우 기반 점검장비가 실시간성을 제공하지 않아 이기종간의 데이터 통신에 대한 주기를 만족해주지 못하는 단점이 있으며, 이러한 문제를 해결하기 위해 고가의 상용 솔루션을 이용하여 윈도우 기반의 점검장비에 실시간성을 보장해주고 있다. 본 논문에서는 고가의 상용 솔루션을 대체하는 실시간 이식 커널인 RTiK-MP를 기반으로 하는 실시간 점검장비 소프트웨어를 설계하는 방법을 제시하며, 성능을 검증하기 위해 고속으로 통신하는 유도탄과 연동시험을 통해서 실시간성과 데이터 정확성을 측정하고 이를 검증하였다.

• 대한임베디드공학회논문지
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• 제13권4호
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• pp.187-194
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• 2018

The operating system for IoT should have a small memory footprint and provide low power state, real-time, multitasking, various network protocols, and security. Although the Zephyr kernel, an operating system for IoT, released by the Linux Foundation in February 2016, has these features but errors generated by the user code can generate fatal problems in the system because the Zephyr kernel adopts a single-space method that both the user code and kernel code execute in the same space. In this research, we propose a space separation method, which separates kernel space and user space, to solve this problem. The space separation that we propose consists of three modifications in Zephyr kernel. The first is the code separation that kernel code and user code execute in each space while using different stacks. The second is the kernel space protection that generates an exception by using the MPU (Memory Protection Unit) when the user code accesses the kernel space. The third is the SVC based system call that executes the system call using the SVC instruction that generates the exception. In this research, we implemented the space separation in Zephyr v1.8.0 and evaluated safety through abnormal execution of the user code. As the result, the kernel was not crashed by the errors generated by the user code and was normally executed.

• 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.