民航维修信息系统中的信息熵指标研究

介绍了维修信息系统(主要是民航维修信息系统)的现状,讲解了维修策略中以可靠性为中心的维修(RCM)理念,继而讨论了维修信息系统与可靠性为中心的维修(RCM)在实现上的困难。通过引入信息熵概念和信息熵指标,为维修信息系统中的数据应用开辟新的观点。     

基于RCM理论的电气设备故障诊断专家系统

大工业生产牵一发而动全身,如何降低设备故障率,使设备安全、稳定、长周期地运行是每个企业迫切需要解决的问题.过去采用的传统故障诊断方法已经越来越不适应现代设备诊断的需要,而专家系统作为一个较为成熟的理论,由于其能产生巨大的经济效益,已经被越来越多地应用在设备故障诊断上.与故障诊断相对应,人们也越来越注重设备的维修,诊断的目的就是为了维修.以可靠性为中心的维修,即RCM理论,是近年来人们提出的一种新的设备维修管理模式,与普通的维修方式相比,RCM更加注重维修结果.本文根据RCM理论和专家系统的发展历史和基本理论,认为将专家系统基本理论与RCM理论结合起来,可构造出极为有效并且实用的电气设备故障诊断专家系统.这类系统能在最短的时间内运用逻辑推理和专家经验对设备进行故障诊断,在指出症结的同时,给出有效的处理意见.这样在故障发生前就对设备采取一定的预防性维修策略,从而从根本上避免了故障的发生,真正做到防患于未然.     

基于RCM的轨道交通车辆计划维修任务确定方法研究

RCM(以可靠性为中心的维修)分析是目前制定高端装备计划维修要求的主流方法,旨在保证装备固有安全性及服务可靠性前提下,最大限度降低维修成本。依据我国轨道交通产品(如高速动车组)运维特点,本文阐述了基于国际标准的轨道交通产品RCM分析方法,并结合具体分析案例,通过RCM分析结果与现有检修规程计划维修任务对比分析,说明了应用RCM分析开发检修规程的优越性。     

基于RCM的设备维修管理平台研究与开发

以可靠性为中心的维修(Reliability-centered Maintenance,RCM)在设备维修方面有着重要意义.预防性维修是RCM的重要内容.该文在几种优化的预防性维修策略基础上,重点研究了周期预防性维修.根据经济性的原则,得出了装备最佳保养周期的计算方法,并用MATLAB仿真进行了验证.利用C#和MATL...     

移动风险控制评估系统设计

以可靠性为中心的维修(RCM)软件系统能够有效提高设备维护效率和降低维护成本,同时应用移动设备能够及时准确地记录现场数据,进一步提高工作效率.介绍了一款基于移动设备的风险控制评估系统,重点阐述了在移动客户端应用风险控制矩阵理论的设计过程.此系统通过建立安全、生产、维修、环境四个风险控制矩阵模型和评估数据,结合定量与定性方法评估大中型设备存在的风险.该评估系统在实际应用中辅助设备管理人员制定维修策略,取得了良好的效果.     

RCM模型决策系统设计

对RCM模型决策系统进行了需求分析,确定了进行模型辅助RCM决策所需的信息,数据处理方式以及如何利用模型辅助决策。所需的信息包括故障信息、维修信息和费用信息等,数据处理主要是对原始故障及维修数据的统计分析,模型主要用于计算最佳工作间隔期和评估工作组合。设计了RCM模型决策系统框架结构及详细流程,改变了以前RCM分析的工作方式,实现了主客观相结合,加强了数据审核,为RCM分析质量提供了保证。提出了系统实现的关键技术,给出了可供参考的实现方法。     

短波自适应通信系统的现状与发展

文章以美军为主,介绍了短波自适应通信系统的主要组成设备和相关通信协议,概述了短波自适应通信系统的主要应用,并提出了对短波自适应通信系统未来发展的展望。     

电站设备状态评价与维修决策系统开发与应用

为了解决电站设备在实际运行过程中因运行工况复杂导致难以对设备可靠性水平进行有效地分析评价,且电站设备在后续维修过程中存在临时性检修频繁、维修不足、维修过剩、盲目维修等问题,因此开发了一套电站设备状态评价与维修决策系统。以机器学习作为算法支撑,结合热工专业知识建立基于数据驱动的热工过程模型,并利用该模型对现场运行设备进行实时在线状态监测和评估,为维修决策和故障诊断提供基础信息,对于科学指导发电辅助设备乃至机组运行管理和维修决策具有重要意义。     

短波通信中分布式干扰的效能分析

通过分析短波通信中分布式干扰的应用,研究了分布式干扰设备的组成及其关键技术和随机二元码调制信号的特性,在此基础上,利用Matlab软件中的Simulink模块仿真分析了分布式干扰系统采用随机二元码调制信号对短波通信系统的干扰效能,由仿真结果可以看出分布式干扰可以取得与集中式大功率干扰相当甚至更好的干扰效果。     

结合大数据的短波广域分集技术

为了提高短波通信保障能力,提出了一种结合大数据的短波广域分集技术,充分发挥大数据在短波选频中的辅助决策功能以及天线阵在短波频段的分集接收功能,有效降低单个接收信道质量恶化对短波通信造成的不利影响,显著提高短波机动用户接入地面有线通信网的可通率和通信质量。该技术架构和设计可以为下一代短波接入技术提供参考。     

New methods for the condition monitoring of level crossings

Level crossings represent a high risk for railway systems. This paper demonstrates the potential to improve maintenance management through the use of intelligent condition monitoring coupled with reliability centred maintenance (RCM). RCM combines advanced electronics, control, computing and communication technologies to address the multiple objectives of cost effectiveness, improved quality, reliability and services. RCM collects digital and analogue signals utilising distributed transducers connected to either point-to-point or digital bus communication links. Assets in many industries use data logging capable of providing post-failure diagnostic support, but to date little use has been made of combined qualitative and quantitative fault detection techniques. The research takes the hydraulic railway level crossing barrier (LCB) system as a case study and develops a generic strategy for failure analysis, data acquisition and incipient fault detection. For each barrier the hydraulic characteristics, the motor's current and voltage, hydraulic pressure and the barrier's position are acquired. In order to acquire the data at a central point efficiently, without errors, a distributed single-cable Fieldbus is utilised. This allows the connection of all sensors through the project's proprietary communication nodes to a high-speed bus. The system developed in this paper for the condition monitoring described above detects faults by means of comparing what can be considered a ‘normal’ or ‘expected’ shape of a signal with respect to the actual shape observed as new data become available. ARIMA (autoregressive integrated moving average) models were employed for detecting faults. The statistical tests known as Jarque–Bera and Ljung–Box have been considered for testing the model.     

Computer-aided RCM-based plant maintenance management system

In most of the industries, classical reliability-centered maintenance (RCM) is employed to decide the maintenance strategies using reliability data without having adequate interaction with the design and operational systems. This means that the RCM process will be conducted with no or limited access to the design and operational data/knowledge. Commonly, the developed maintenance strategies are implemented and managed within the computerized maintenance management system (CMMS), which is usually separate from the RCM automated environment. This paper presents the detailed system design and mechanism of improved RCM process as integrated with CMMS. The proposed solution is integrated with design and operational systems and consolidates some successful maintainability approaches to formulate an effective solution for optimized plant maintenance. The major components of the enhanced RCM process are identified and a prototype system is implemented as integrated with the various modules of the adopted CMMS (MAXIMO™). A case study is used to show the effectiveness of the proposed RCM-based CMMS solution in optimizing plant maintenance over the traditional approaches.     

基于移动终端的通信设备和线路巡检系统设计

为便于电力通信设备和线路运行的维护管理与规范化作业,开发了基于移动终端的巡检系统。构建了包括外网移动端、客户端、内网数据库的三层架构体系,在Web服务器的顶端采用MyBatis持久层框架,提出了HTML5技术的移动Web App开发模式,利用Eclipse集成开发环境和ORACLE关系型数据库构建内外网移动交互平台,并在移动终端、网络层、应用层、数据库等四个层次进行安全防护。巡检系统的应用情况表明,该移动终端巡检系统实现了巡检任务的自动分派以及检修任务的跟踪处理,并能对通信设备的台账及线路运行资料进行现场核对和更新,能够根据巡检与检修的次数以及隐患点自动完成对通信设备运行状况的等级评价,提高了现场操作的规范性和时效性以及运维人员的工作效率,确保了通信设备和线路安全稳定运行。     

基于远程动态重构的通用靶场测控系统设计

为方便设备的远程升级维护,提高测试效率,提出一种基于远程动态重构的通用靶场测控系统设计方案。通过PXI总线将试验所需的各模块集成于前端测控组合,由后端主控计算机完成对前端设备的综合调度,由数据处理计算机完成遥测数据的实时处理。利用可编程片上系统实现测控组合中部分模块的远程动态重构功能,使同一设备适应不同RS422通讯协议,适应调频、扩频等不同的测控体制。测试结果证明,系统可靠性高,模块重构时间短。该方案有效节约资源,具有广阔的应用前景。     

An optimal maintenance policy based on generalized stochastic Petri nets and periodic inspection

Periodic maintenance of equipment is essential for its optimum performance, thereby enabling production efficiency. In the past, studies on preventive maintenance of automated manufacturing systems (AMS) determined the optimal preventive maintenance policy under different performance indexes. Generally, most hypotheses indicate that equipment reliability can be restored to 1.0 through preventive and corrective maintenance. However, in practical application, the implementation of preventive maintenance results in partial deterioration of equipment; moreover, the reliability of equipment cannot be restored to as‐good‐as‐new. In addition, the greater the complexity of connections of the equipment, the greater is the difficulty in determining the timing for preventive maintenance. On account of these characteristics, generalized stochastic Petri nets (GSPN) are well‐suited for the implementation of preventive maintenance. Therefore, this paper applies GSPN for deciding the optimal maintenance policy and constructing models for different levels of maintenance and renewal for an AMS with a serial‐parallel layout. As a result of the application of GSPN, the following optimal maintenance policy for an AMS was obtained in this study: Preventive maintenance conducted at intervals of every 240 hours will reduce cost by 46% as opposed to the practice of replacing defective parts when necessary. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

基于案例的RCM分析系统案例库的设计

案例库是基于案例的以可靠性为中心的维修(RCM)分析系统的核心,其内容和结构对系统推理效率具有重要的影响。介绍了基于案例的RCM分析系统,提出了案例库的设计目标,分析了案例的主要成份构成,阐述了面向对象、基于关系数据库的案例库组织形式以及索引机制。案例库的设计为基于案例的RCM分析系统的开发和实现奠定了坚实的基础。     

基于NB-IoT的海岛海水淡化远程监控系统

针对我国海岛海水淡化设备无人少人值守、集中监管力度不足、设备运行可靠性差以及设备维护检修时效性差等问题,设计开发了一套海水淡化远程监控系统.通过对比主流通信手段和方式,从实用性、经济性、可靠性角度出发遴选窄带物联网(NB-IoT)作为该套监控系统的通信组网方式;从系统硬件设计和软件开发两个方面进行详细阐述,硬件方面重点...     

复杂装备故障预测与健康管理系统初探

故障预测与健康管理(PHM)系统是新型维修保障模式—自主后勤保障的重要组成部分,对提高复杂装备的战备完好性和降低维修成本具有重要意义;首先介绍PHM系统基本概念及主要组成,并对在复杂装备全寿命周期实施PHM的必要性进行分析;综合论述了PHM系统实现中的关键支撑技术:基于RCM分析的方案设计、基于匹配度的健康状态评估和基于剩余寿命预测的维修决策;最后给出了PHM系统在无人机装备中的应用实例;国内外应用情况表明,PHM系统可显著提高维修保障效率并降低维修保障费用,可实现经济可承受性目标。