• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 심포지엄 논문집 정보 및 제어부문
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• pp.150-152
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• 2004

The battery charge/discharge process, the final step of the secondary battery production process, requires real-time precision controls for improving both lifetime and performance of the battery cell. In this paper, we present embedded system design for precision control of the secondary battery charge/discharge production process using low power embedded processor based on embedded linux. This system receive charge/discharge command from the main server through ethernet. Compared to existing charge/discharge control system, our design makes low cost and precision control system possible.

• 대한임베디드공학회논문지
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• 제14권5호
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• pp.249-258
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• 2019

In the cyber-physical system, big data collected from numerous sensors and IoT devices is transferred to the Cloud for processing and analysis. When transferring data to the Cloud, merging data into one single file is more efficient than using the data in the form of split files. However, current merging and splitting operations are performed at the user-level and require many I / O requests to memory and storage devices, which is very inefficient and time-consuming. To solve this problem, this paper proposes kernel-level partitioning and combining operations. At the kernel level, splitting and merging files can be done with very little overhead by modifying the file system metadata. We have designed the proposed algorithm in detail and implemented it in the Linux Ext4 file system. In our experiments with the real Cloud storage system, our technique has achieved a transfer time of up to only 17% compared to the case of transferring split files. It also confirmed that the time required can be reduced by up to 0.5% compared to the existing user-level method.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제13권5호
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• pp.271-281
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• 2007

임베디드 운영체제에서의 실시간성 지원은 현대 임베디드 시스템에서 추가사항이 아니라 필수사항이다. 이러한 임베디드 운영체제가 사용되는 시스템의 실시간성 지원을 충족하기 위해서는 시스템 내 실시간성이 요구되는 태스크들의 스케줄링 가능성 여부가 중요하며, 이를 시스템 수행 전 검증해야 할 필요가 있다. 스케줄링 가능성 분석에서 핵심적인 부분 중의 하나는 태스크의 최악실행시간을 구하는 것이다. 기존의 최악실행시간 분석도구들은 일반적인 응용 태스크 즉, 응용 프로그램의 최악실행시간을 위주로 분석하였기 때문에 응용 프로그램들이 운영체제에 의해 스케줄링시 영향을 받는 운영체제의 스케줄링 관련 프리미티브들(스케줄러, 인터럽트 서비스 루틴등)에 대한 고려는 전혀 하지 않고 있다. 본 논문에서는 임베디드 운영체제 중에 널리 사용하고 있는 임베디드 리눅스가 사용되는 임베디드 시스템에서의 스케줄링 관련 프리미티브들을 고려하는 최악실행시간 분석 도구를 설계하고 구현한다. 이 분석도구는 일반적인 응용 프로그램 뿐만 아니라 임베디드 리눅스 커널내의 스케줄링에 영향을 미치는 관련 프리미티브들의 최악실행시간을 분석하여 스케줄링 분석의 정확성을 더욱 더 높인다. 이 도구는 현재 임베디드 환경에서 통합개발환경으로 제작된 이클립스(Eclipse)의 플러그인 형태로 개발되어 어떠한 플랫폼에서도 동작 가능하고 사용자가 사용하기에 편리한 인터페이스 및 기능을 제공할 수 있도록 구현한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(4)
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• pp.231-234
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• 2002

As control programs are becoming larger and more complex, the capacity of a microprocessor in a TV set needs to have a CPU with 32 bits or more. Also the embedded system such like a digital TV set uses RTOS (Real Time Operating System)[1]. LGE Co. has developed a digital TV system that displays HD (High definition) signal with the AR7TDMI CPU and the commercial RTOS[2]. This thesis made improvements on problems caused by porting embedded LiNUX in limited size memory (2 mega byte) instead of RTOS[3]. The advantages of changing to embedded LiNUX take away running OS royalty that needed to make TV sets[4].

• 대한임베디드공학회논문지
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• 제12권1호
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• pp.1-10
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• 2017

Recently, with the ever-increasing complexity of industrial robot systems, it has been greatly attention to adopt a multi-core based motion controller with high cost-performance ratio. In this paper, we propose a software architecture that aims to utilize the computing power of multi-core processors. The key concept of our architecture is to use shared memory for the interplay between threads running on separate processor cores. And then, we have integrated our proposed architecture with an industrial standard compliant IDE for automatic code generation of motion runtime. For the performance evaluation, we constructed a test-bed consisting of a motion controller with Preempt-RT Linux based dual-core industrial PC and a 3-axis industrial robot platform. The experimental results show that the actuation time difference between axes is 10 ns in average and bounded up to 689 ns under $1000{\mu}s$ control period, which can come up with real-time performance for industrial robot.

• Journal of Communications and Networks
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• 제12권3호
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• pp.266-274
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• 2010

The efficient network resource management is one of the important topics in a real-time system. In this paper, we present a practical network resource management framework, control-theoretic packet scheduler (CPS) system. Using our framework, an operating system can schedule both input and output streams accurately and efficiently. Our framework adopts very portable feedback control theory for efficiency and accuracy. The CPS system is able to operate independent of the internal network protocol state, and it is designed to schedule packet streams in fine-grained time intervals to meet the resource requirement. This approach simplifies the design of the CPS system, and leads us to obtain the intended output bandwidth. We implemented our prototype system in Linux, and measured the performance of the network resource management system under various network QoS constraints. The distinctive features of our principles are as follows: It is robust and accurate, and its operation is independent of internal network protocols.

• 제어로봇시스템학회논문지
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• 제21권2호
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• pp.173-178
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• 2015

Cloud systems are efficient models that can utilize various infrastructures, platforms, and applications regardless of the type of clients. This paper proposes a cloud-based integrated development environment (IDE) for robot software development which would make software development easier. The proposed system provides robot simulation to test the robot HW modules or robot systems for development and testing of software operating in a robot system with two or more different operating systems (OS) such as Windows, Linux, and real-time OS. This paper implements and evaluates the proposed system using OPRoS [33].

• 반도체디스플레이기술학회지
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• 제10권1호
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• pp.113-118
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• 2011

This paper proposes computer visual inspection algorithms for PCB defects which are found in a manufacturing process. The proposed method can detect open circuit and short circuit on bare PCB without using any reference images. It performs adaptive threshold processing for the ROI (Region of Interest) of a target image, median filtering to remove noises, and then analyzes connected components of the binary image. In this paper, the connected components of circuit pattern are defined as 6 types. The proposed method classifies the connected components of the target image into 6 types, and determines an unclassified component as a defect of the circuit. The analysis of the original target image detects open circuits, while the analysis of the complement image finds short circuits. The machine vision inspection system is implemented using C language in an embedded Linux system for a high-speed real-time image processing. Experiment results show that the proposed algorithms are quite successful.

• 반도체디스플레이기술학회지
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• 제10권3호
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• pp.53-59
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• 2011

This paper proposes a new method of traffic signal detection and recognition in an RGB color model. The proposed method firstly processes RGB-filtering in order to detect traffic signal candidates. Secondly, it performs adaptive threshold processing and then analyzes connected components of the binary image. The connected component of a traffic signal has to be satisfied with both a bounding box rate and an area rate that are defined in this paper. The traffic signal recognition system is implemented using C language in an embedded Linux system for a high-speed real-time image processing. Experiment results show that the proposed algorithms are quite successful.

• 반도체디스플레이기술학회지
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• 제9권3호
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• pp.59-63
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• 2010

This paper proposes computer visual inspection algorithms for various LCD defects which are found in a manufacturing process. Modular vision processing steps are required in order to detect different types of LCD defects. Those key modules include RGB filtering for pixel defects, gray-scale morphological processing and Hough transform for line defects, and adaptive threshold for spot defects. The proposed algorithms can give users detailed information on the type of defects in the LCD panel, the size of defect, and its location. The machine vision inspection system is implemented using C language in an embedded Linux system for a high-speed real-time image processing. Experiment results show that the proposed algorithms are quite successful.