Development of a Web-based RCM system for the driverless Rubber-Tired K-AGT system

The Korean Railroad Research Institute (KRRI) developed the rubber-tired AGT system (Model: K-AGT) between 1999 and 2005. The K-AGT is a light rail transit system does not require a driver and generally operates on an elevated railroad for transporting passengers. Accidents caused by driverless vehicles can severely affect social confidence, safety and economy. Therefore, it is very important to minimize the occurrences of such faults, and to accurately perform detailed maintenance tasks and thoroughly investigate the cause of any repeated failures. This research develops the web-based reliability centered maintenance (RCM) system for the K-AGT train system. The framework of the RCM system is based on performing a failure mode and effects analyses (FMEA) procedure on all the sub-systems in the K-AGT system. Out of the devices that have a low reliability, the high failure ranked devices are included high on the list for performing the overall maintenance plans. Through registration of historical failure data and the reliability indexes, the results of the FMEA can be updated. Such a process is repeated continuously and can achieve very accurate predictions for device operational lifetimes and failure rates. Also, the RCM system is designed so that workers can refer to the expert system for the latest procedures to perform the required diagnosis and repair of any failure. The overall RCM system consists of a failure/task management system, a preventive maintenance system, an expert system, a material management system, and an approval system. This research describes the development of the preventive maintenance system and the expert system that have been produced because these are the main functions for the RCM system. This paper was recommended for publication in revised form by Associate Editor Dae-Eun Kim Myung-Won Suh is a Professor of Mechanical Engineering. During 1986–1988, he worked for Ford motor company as researcher. From 1989–1995, he worked in technical center of KIA motors. He took a BS degree in Mechanical Engineering from Seoul National University and an MS degree in Mechanical Engineering from KAIST, South Korea. He obtained his Doctorate at the University of Michigan, USA, in 1989. His research areas include structure and system optimization, advanced safety vehicle and reliability analysis & optimization. Chul-Ho Bae is a PhD candidate at Sungkyunkwan University in Suwon, South Korea. He accomplished fellowship work as researcher at Mississippi State University, USA, in 2003 and 2005. He worked in Institute of Advanced Machi-nery and Technology (IMAT) as a Research Assistant in 2004. He was a part time Lecturer in computer aided Mechanical Engineering of Ansan College of Technology, Suwon Science College, and Osan College during 2004–2005. He took a BS Degree in Mechanical Design and an MS Degree in Mechanical Engineering from the Sungkyunkwan University. His research interests include computer aided engineering, reliability engineering, and optimization.     

计及维修因素的牵引变电站电气主接线可靠性分析

牵引变电站的可靠性直接关系到铁路运输安全,其电气主接线的可靠性是牵引变电站可靠性研究的重要内容。为此建立了牵引变电站电气主接线在不可维修和可维修情况下的2种可靠性模型,给出了2种不同模型下的平均无故障工作时间（TMTBF）和平均首次故障前工作时间（TMTTFF）的计算方法。计算结果表明：牵引变电站电气主接线可维修时,T...     

基于相似产品的车床高速主轴系统可靠性预计

针对目前机械系统可靠性预计方法使用条件复杂,载荷变化范围较大,缺乏公认的、普遍适用的方法的现状,利用相似产品的可靠性数据,结合手册对数控机床主轴系统设计方案进行可靠性预计,考虑载荷的变化对机械零件的影响,分析不同载荷下系统可靠度随时间变化的趋势。结果表明:改善主轴系统薄弱点,减小当量载荷与额定载荷的比值能有效提高系统的可靠度和平均无故障工作时间。     

全自动可转位刀片周边磨床的可靠性分析

在对全自动可转位刀片周边磨床早期故障以及失效机理分析的基础上,采用试验方法,对其整机及关键功能部件进行了可靠性研究,获得指数分布下机床的真实故障数据、故障分析结果和磨床的平均无故障运行时间,提出该磨床在今后设计、制造和装配过程中的建议.试验证明,该机床的可靠性指标符合要求,在改进后将获得更高的可靠性指标值.     

中频接收机模拟测试台的可靠性设计与实现

依据原理框图建立可靠性模型;采用故障树模式,分析电子系统在工作时可能产生的潜在电路;对潜在电路的危害性进行定性分析,利用逻辑推理的方法找出截断或消除潜在电路的关键部位,依分析结果改进设计方案,画出改进后的原理框图进行可靠性设计,设计生产出的中频接收机模拟测试台一次成功,实例说明电子系统进行可靠性设计是保证产品质量的有效方法。     

Age-related maintenance versus reliability centred maintenance: a case study on aero-engines

Reliability Centred Maintenance (RCM) is a procedure carried out as part of the logistic support analysis (LSA) process and is described in the US Department of Defence Military Standards (Mil Std 2173). RCM allows logisticians the opportunity to determine the best maintenance policy for each component within a system. However, the only data that are available to carryout RCM using Mil Std 2173 are of MTBF. This implies that all the necessary mathematical models need to be based on the exponential distribution. This is a serious drawback to the whole concept of RCM as the exponential distribution cannot be used to model items that fail due to wear, or any other mode that is related to their age. In this paper, a new approach to RCM is proposed using the concepts of soft life and hard life to optimise the total maintenance cost. For simplicity, only one mode of failure is considered for each component. However, the model can be readily applied to multiple failure modes. The proposed model is applied to find the optimal maintenance policies in the case of military aero-engines using Monte Carlo simulation. The case study shows a potential benefit from setting soft lives on relatively cheap components that can cause expensive, unplanned engine rejections.     

高频开关电源系统可靠性指标MTBF的计算方法

给出了影响高频开关电源系统可靠性的主要原因和不同电源系统可靠性指标MTBF的计算方法。     

建设电信级业务运营支撑系统(BOSS)的探讨

本文从物理设备层、业务系统层、业务整体方案层来剖析电信级BOSS系统的特性,讨论了电信级BOSS的评估机制,并提出了电信级BOSS系统的建设思路。     

电荷放大器可靠性分析

介绍了电荷放大器在存储测试系统中的作用,详细说明了电荷放大器工作原理,推导出电荷量与输出电压之间的关系。通过故障树的方法对电荷放大器的可靠性进行分析,得出电荷放大器的MTBF和可靠性曲线,定量计算出电阻、电容、焊点和芯片在一个完整的存储测试电路中的失效率,定性的分析出不同部分对整体系统失效率的影响度。     

系统MTBF和MTTR的一种求解方法

针对目前MTBF和MTTR获取的不规范性,应用贝叶斯估计求解系统的MTBF和MTTR,依据MTBF和MTTR的先验分布,利用贝叶斯公式求出它们的后验分布,然后利用贝叶斯估计得到MTBF和MTTR的估计值。最后运用一个实例验证了该方法的正确性。