• Title/Summary/Keyword: reliability requirements

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시제열차 개발에서의 신뢰성 관리 체계 (Reliability Management Process for the Development of a Prototype Train)

  • 최성훈;박춘수;이태형
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 춘계학술대회 논문집
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    • pp.1083-1088
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    • 2008
  • The first task for the development of a train system is to define the system and to determine its requirements. Reliability target is one of the requirements defined in the system requirements. In railway applications it is advised to follow the procedures given in IEC 62278 to fulfill reliability requirements. The reliability requirements are derived from the customer's needs. The way in which the system requirements reflect the customer's needs is strongly dependent on the characteristics of the product. In general the customer of commercial trains presents the system requirements from their needs. However, the relation between the customer and supplier is equivocal for a project to development a prototype train, and the reliability program should be different from that of an usual commercial project. This paper deals with the reliability management and assessment plan carried out for the on-going "Next generation high-speed train development project".

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시제열차 개발에서의 신뢰성 관리 체계 (Reliability Management Process for the Development of a Prototype Train)

  • 최성훈;박춘수;이태형
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 추계학술대회 논문집
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    • pp.206-210
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    • 2007
  • IEC 62278 presents a process to implement a consistent approach to the management of reliability for railway applications. A reliability program has to be established at the outset of a project in order to manage reliability activities effectively through the life cycle. The first step of the reliability program is to evaluate reliability requirements and targets based on the system specifications. The system specifications are derived from the customer's needs. The way in which the system requirements reflect the customer's needs is strongly dependent on the characteristics of the product. In general the customer of commercial trains presents the system requirements from their needs. However, the relation between the customer and supplier is equivocal for a project to development a prototype train, and the reliability program should be different from that of an usual commercial project. This paper deals with a process to manage reliability activities for the development of a protype train based on the experiences obtained from the development of the Korea High-Speed Train: Hanvit-350.

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신제품 개발에 따른 효과적인 신뢰성 시험 설계 (Design of Effective Reliability Tests for New Products)

  • 박부희;장중순;김기영;이재훈;김선진;천성일;정기윤;김덕진;이춘범
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제9권2호
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    • pp.107-119
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    • 2009
  • Reliability tests should be designed to verify whether reliability requirements are satisfied or not effectively and efficiently. The portion of reliability requirements that a reliability test scheme composed of different types of tests can cover is defined as test coverage in software engineering. For the cases of hardwares, to be effective, a reliability test scheme should enhance the test coverage. This study is to develop an evaluation method of test coverage for a reliability test scheme proposed for new products. Case studies are also given.

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두 가지의 신뢰도 요구조건을 만족하기 위한 직렬 시스템의 최적 중복 구조 설계 (Redundancy optimization to meet two reliability requirements)

  • 박준서;김재훈;최성규;김종운
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2006년도 추계학술대회 논문집
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    • pp.1198-1202
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    • 2006
  • MTBF(Mean Time Between Failure)와 MTBSF(Mean Time Between Service Failure) are two representative quantitative reliability requirements for railway systems. There are the case that both of the two requirements are presented and the case that only one of them is presented in the specification of railway systems. we deal with the redundancy allocation problem to meet the two reliability requirements. The redundancy increases MTBSF while it decreases MTBF. Parallel redundancy and the exponential lifetime distribution of components are considered for the series systems. Mathematical model and example are presented for the redundancy optimization problem of minimizing the cost subjecting to MTBF and MTBSF requirements.

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신뢰성과 관련된 요구사항에 대하여 ISO 9000, QS-9000, ISO/TS 16949 시스템의 비교분석 (Analysis of the Reliability Requirements in ISO 9000, QS-9000, ISO/TS 16949 system)

  • 박채원;김광섭
    • 한국신뢰성학회:학술대회논문집
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    • 한국신뢰성학회 2004년도 정기학술대회
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    • pp.249-261
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    • 2004
  • 최근 10여년 사이에 여러 국가의 많은 기업들이 ISO 9000 인증을 획득하였고 특정 분야에서는 ISO 9000에 고객에 의해 특별히 요구되는 내용을 추가하여 인증이 이루어지고 있는데 특히 자동차 분야의 QS 9000과 ISO/TS 16949가 그 예가 될 수 있겠다. 따라서 인증의 근간이 되는 규격인 ISO 9000을 비롯하여 QS 9000과 ISO/TS 16949에서 요구되는 내용이 매우 중요시된다고 할 수 있으며 또한 그 중에서도 제품의 설계 및 제조과정에서 언급되고 있는 설계 FMEA나 공정 FMEA 및 게이지 R&R과 같은 신뢰성과 관련된 내용들은 특히 중요한 요소라고 할 수 있겠다. 이에 본 연구에서는 각 시스템에 있어 신뢰성 관련 내용을 검토, 분석함으로써 각 시스템에서 신뢰성 요구 사항들이 어떻게 규정되어 있는지를 비교, 분석하고 그 적용 사례를 통하여 합리적 적용 방법들을 제시하였다. 또한 자동차 분야 외에도 이와 같은 신뢰성과 관련하여 요구되는 사항들이 많이 있을 수 있겠으나 이에 대해서는 추후 연구, 검토를 계속해 나갈 예정이다.

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Software Reliability of Safety Critical FPGA-based System using System Engineering Approach

  • Pradana, Satrio;Jung, Jae Cheon
    • 시스템엔지니어링학술지
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    • 제14권2호
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    • pp.49-57
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    • 2018
  • The main objective of this paper is come up with methodology approach for FPGA-based system in verification and validation lifecycle regarding software reliability using system engineering approach. The steps of both reverse engineering and re-engineering are carried out to implement an FPGA-based of safety critical system in Nuclear Power Plant. The reverse engineering methodology is applied to elicit the requirements of the system as well as gain understanding of the current life cycle and V&V activities of FPGA based-system. The re-engineering method is carried out to get a new methodology approach of software reliability, particularly Software Reliability Growth Model. For measure the software reliability of a given FPGA-based system, the following steps are executed as; requirements definition and measurement, evaluation of candidate reliability model, and the validation of the selected system. As conclusion, a new methodology approach for software reliability measurement using software reliability growth model is developed.

Localization Requirements for Safe Road Driving of Autonomous Vehicles

  • Ahn, Sang-Hoon;Won, Jong-Hoon
    • Journal of Positioning, Navigation, and Timing
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    • 제11권4호
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    • pp.389-395
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    • 2022
  • In order to ensure reliability the high-level automated driving such as Advanced Driver Assistance System (ADAS) and universal robot taxi provided by autonomous driving systems, the operation with high integrity must be generated within the defined Operation Design Domain (ODD). For this, the position and posture accuracy requirements of autonomous driving systems based on the safety driving requirements for autonomous vehicles and domestic road geometry standard are necessarily demanded. This paper presents localization requirements for safe road driving of autonomous ground vehicles based on the requirements of the positioning system installed on autonomous vehicle systems, the domestic road geometry standard and the dimensions of the vehicle to be designed. Based on this, 4 Protection Levels (PLs) such as longitudinal, lateral, vertical PLs, and attitude PL are calculated. The calculated results reveal that the PLs are more strict to urban roads than highways. The defined requirements can be used as a basis for guaranteeing the minimum reliability of the designed autonomous driving system on roads.

Lloyds Register Asia Rail Systems Reliability Lifecycle Management

  • Jonathan, Bouchard
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2003년도 추계학술대회 논문집(I)
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    • pp.27-43
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    • 2003
  • Reliability Lifecycle from Concept to In-Service Operation and Maintenance. Reliability management must consider - SAFETY - SERVICE REQUIREMENTS. Reliability targets/objectives can be specified at feasibility stage. Reliability analysis to support design process. Reliability assessment to support reliability growth or contractual demonstration. Maintenance optimisation to improve reliability during lifetime of operation. Lessons learnt incorporated into next generation of trains.

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제조 로봇용 서보모터의 양산성능 평가 연구 (A study on the mass production performance evaluation of servomotors for manufacturing robots)

  • 류경하;이태현;박종원;권혁성;강보식
    • 드라이브 ㆍ 컨트롤
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    • 제19권4호
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    • pp.91-96
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    • 2022
  • The performance and reliability of foreign servomotors and domestic servomotors for manufacturing robots were compared and verified. The mass productivity was confirmed by satisfying the requirements of the demanding companies. The servomotor was designed in consideration of mass productivity while satisfying the requirements of the demanding company. It was mounted on a real robot to check its performance and reliability. To secure mass-production performance, we designed and manufactured easy-to-manufacture parts and jigs to manufacture servomotors and achieved the goal of the mass-production evaluation of servomotors through individual performance evaluation, robot mounting test evaluation, and supplementation.

L.E.O. Satellite Power Subsystem Reliability Analysis

  • Zahran M.;Tawfik S.;Dyakov Gennady
    • Journal of Power Electronics
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    • 제6권2호
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    • pp.104-113
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    • 2006
  • Satellites have provided the impetus for the orderly development of reliability engineering research and analysis because they tend to have complex systems and hence acute problems. They were instrumental in developing mathematical models for reliability, as well as design techniques to permit quantitative specification, prediction and measurement of reliability. Reliability engineering is based on implementing measures which insure an item will perform its mission successfully. The discipline of reliability engineering consists of two fundamental aspects; $(1^{st})$ paying attention to details, and $(2^{nd})$ handling uncertainties. This paper uses some of the basic concepts, formulas and examples of reliability theory in application. This paper emphasizes the practical reliability analysis of a Low Earth Orbit (LEO) Micro-satellite power subsystem. Approaches for specifying and allocating the reliability of each element of the power system so as to meet the overall power system reliability requirements, as well as to give detailed modeling and predicting of equipment/system reliability are introduced. The results are handled and analyzed to form the final reliability results for the satellite power system. The results show that the Electric Power Subsystem (EPS) reliability meets the requirements with quad microcontrollers (MC), two boards working as main and cold redundant while each board contains two MCs in a hot redundant.