Inspection-Based Policy Considering Human Errors for Three-Stage Delay Time Degradation Systems

A periodic inspection policy for a single component system based on a three-stage failure process is proposed, and two different kinds of failures covering “hard” and “human” are considered in the proposed policy. The system is periodically inspected and inspections are perfect so that they can identify the intended defect. If the severe defect is detected by an inspection, an immediate repair is needed. However, once the system is identified to be in the minor defective state, there are two options. The first is to do nothing till the arrival of identifying the severe defect or hard failure, and the second is to repair immediately. Repair for any defect can renew the system with a limited probability such that the system may fail after repair due to human errors, which is common in many industrial applications. Two models are constructed by minimizing the expected cost per unit time and compared. We provide a numerical example to demonstrate the proposed model.     

Optimal Research on Equipment Maintenance Unequal Time-Interval Based on Simulation

The paper deals with systems suffered from gradual deterioration. To avoid functional failures and disastrous consequences, such systems should be monitored and preventively maintained. And to promote the maintenance effectiveness, an unequal time-interval maintenance policy was brought forward to substitute fixedinterval preventive maintenance strategy. At the same time, preventive and corrective maintenance actions are both assumed to be imperfect, and their impact on the system is expressed by the increment of failure rate. The case study shown that the unequal time-interval maintenance policy proposed in the paper is of help to promote the availability of the system.     

Optimal Preventive Maintenance Policy with Consideration of Production Wait

In this paper, we consider the replacement of a single unit with catastrophic failure mode. Besides replaced at a preset time, the unit is also replaced at failure time or if it encounters a production wait and its age has reached a threshold. The joint preventive maintenance interval and threshold optimization problem are formulated with the objective of minimizing the expected cost per unit time in long run. A numerical example is presented to illustrate the applicability of the model.     

退化零部件检查方案的优化

针对退化零部件的检查问题,基于延迟时间的概念,分析了退化零部件在类周期检查方案下的更新类型与费用构成.考虑到用解析方法优化检查方案较为困难,而采用了蒙特卡洛仿真的方法.以费用率最小为优化目标,利用MATLAB程序得到了周期检查和类周期检查下的最优检查间隔.通过与解析方法比较,证明了该方法的正确性,并通过一个实例,说明该...     

汽车检测控制系统网络通信技术

为了提高汽车检测控制系统网络通信的质量和效率,对传统的串行、共享文件与网络数据库通信方式进行了比较,提出了一种新的基于Winsocket的通信方式,采用Winsocket技术设计了数据帧和命令帧两种报文结构。在C/S模式下解决了汽车检测控制系统车辆调度和检测数据实时传输网络通信问题,提高了系统运行过程的稳定性与检测数据传输的实时性和可靠性。     

铁路运营隧道检测技术综述

为了解铁路运营隧道检测技术研究与应用情况, 梳理了隧道病害特点与检测方法, 从表观状态、内部状态、几何形态、高精度地面移动检测机器人和数据信息化5个方面, 分析了国内外检测技术现状, 探讨了检测技术体系与发展方向。分析结果表明: 表观状态检测主要有相机摄像和激光扫描技术, 相机摄像系统适用于车载平台, 检测速度达80 km·h-1, 激光扫描系统结构精巧, 检测速度约为5 km·h-1; 图像处理、计算机视觉是表观病害识别的2种技术, 拓展设计病害特征、提高识别效率、降低非病害因素干扰是图像处理技术进一步发展方向, 计算机视觉推广关键在于构建行业级病害样本库; 地质雷达是开展内部状态检测的关键技术, 地耦型雷达速度约为10 km·h-1, 空耦型雷达速度达80 km·h-1, 空耦型雷达检测系统关键在于优化天线结构、信号增强、抑制电气化设施和机械系统振动干扰, 地质雷达、红外热成像、超声层析成像、激光缺陷检测法等检测技术在探测范围、精度、效率等方面具有互补性, 可构成多技术综合运用策略; 几何形态检测主要有激光扫描、激光摄像、惯性测量技术, 激光扫描测量精度高, 速度约为10 km·h-1, 激光摄像速度达60 km·h-1, 提高激光摄像测量精度关键在于系统标定与振动补偿, 可基于惯性测量深化研究开展仰拱上拱变形检测; 发展和推广高精度地面移动检测机器人、检测数据信息化是与隧道规模相适应、状态精准管理相匹配的保障措施; 检测技术体系建议由“车载式快速综合检测+原位与地面移动精确检测+数据信息化平台”3部分组成, 未来发展方向应集中在空耦型雷达快速检测、复合变形快速精确测量、高精度地面移动检测、病害智能识别及多源数据融合分析等方面。      

Modeling the effect of environmental conditions on reliability of wind turbines

The climate condition of a wind farm has a significant influence on the reliability of wind turbines. The climate condition varies with season in a year and hence the reliability changes in a complex way. The purpose of this paper is to model the effect of climate condition on field reliability of wind turbines. The reliability is measured by monthly-averaged mean time between failures(MTBF), and the climate conditions are described by variables of monthly-averaged temperature, relative humidity, rainfall and wind speed. Referring to the physicsof-failure models in accelerated life testing(ALT), we develop a quantitative relation between the MTBF and the climate variables. For a set of field data, the model parameters are estimated by regression, and the insignificant variables are gradually deleted based on the P-value of the regression coefficients. The resulting model is useful for maintenance workload forecasting and preventive maintenance planning, and has a potential to be used in online failure prediction.     

Research on marine structure inspection support system on mobile device platform

Ship and offshore structure often work in very severe environment. Therefore routine inspection and maintenance are essential to keep ship structure and equipment in good state, and can decrease the possibility of sea pollution and safety problems. Besides that, the activity of inspection and maintenance is also directly connected with cost control and condition assessment. Current inspection is still mainly based on paper and pen, so it is rather time-consuming for transferring inspection data from paper to computer system, and more difficult to make calculation based on the inspection records. In this paper, the concept of information integration model and inspection support system using mobile device is introduced. The structuralized data in the information integration model offer much convenience to data transferring. The inspection support system consists of one headquarter management subsystem and one inspector handling subsystem. A mechanism of data exchange between the two subsystems is developed based on standard inspection workflow. The headquarter subsystem works on computer, and the inspector subsystem is mobile application instead of paper and pen. Versatile tests and platform experiments are carried out to demonstrate and confirm the feasibility and validity.     

Optimum Consecutive Preventive Maintenance Scheduling Model Considering Reliability

As an effective means for improving system condition and reducing failures, a reasonable preventive maintenance scheduling guarantees the stability and safety of the system. This paper studies a consecutive maintenance scheduling problem for single-component systems with imperfect maintenance, and an optimum model with minimum reliability constraint for minimal cost rate is developed based on the renewal theory. The agebased and reliability-based maintenance strategies are modeled and compared according to a numerical example based on the degradation data of the actual system, which also verifies the optimality of the reliability-based strategy. At last, the influence of some key parameters is discussed by sensitive analysis.     

Reliability analysis of repairable systems using stochastic point processes

In order to analyze the failure data from repairable systems, the homogeneous Poisson process(HPP) is usually used. In general, HPP cannot be applied to analyze the entire life cycle of a complex, re-pairable system because the rate of occurrence of failures (ROCOF) of the system changes over time rather thanremains stable. However, from a practical point of view, it is always preferred to apply the simplest methodto address problems and to obtain useful practical results. Therefore, we attempted to use the HPP model toanalyze the failure data from real repairable systems. A graphic method and the Laplace test were also usedin the analysis. Results of numerical applications show that the HPP model may be a useful tool for the entirelife cycle of repairable systems.     

铁路工务、电务、供电检测装备发展现状综述

从铁路工务、电务、供电检测装备的类型、检测对象等角度，梳理了各国检测装备的发展概况，分析了综合检测车、专业检测车、搭载式检测装置的发展历史、技术特点与应用情况，比较了国内外同类型检测装备在设计理念、功能集成、运用维护等方面的差异，分析了中国检测装备存在的不足；在此基础上，借鉴国外先进经验并结合中国实际情况，凝练了中国检测装备的发展趋势。研究结果表明：中国铁路工务、电务、供电检测技术取得了长足进步，部分领域达到或接近世界先进水平；但与实际运营需求相比还存在一定差距，主要表现在检测项目不充足，检测设备自动化和智能化水平较低，检测数据利用不充分，检测成本较高等；针对上述问题，检测装备的发展应朝着检测功能综合化、检测装备小型化与模块化、检测过程智能化与无人化的方向发展，形成可靠性高、检测项目齐全、检测数据精准的现代化检测装备体系，以期实现对铁路基础设施的状态维修和全生命周期管理。     

Opportunistic preventive maintenance optimization for multi-unit series systems with combing multi-preventive maintenance techniques

This paper proposes a dynamic opportunistic preventive maintenance (PM) optimization policy for multi-unit series systems by integrating multi PM techniques. Two PM techniques, periodic PM and sequential PM, are considered. Whenever one of the units reaches its reliability threshold, a PM action has to be performed on that unit. At that time the whole system has to be stopped and PM opportunities arise for the other units of the system. An optimal PM practice is determined by maximizing the short-term cumulative opportunistic maintenance (OM) cost savings for the whole system. Numerical examples are given to show how this approach works. Finally, a comparison between the proposed PM policy and the other policies is given.     

船舶液压系统油污染的控制研究

大量统计资料显示,液压系统的故障率70%以上都是由于液压油的污染造成的。增强控制液压油污染的意识,加强对液压油污染的检测,提高液压油管理技术,能有效降低液压系统故障率。     

新型全自动轨道巡检车动力学性能

为准确评估某新型全自动智能轨道巡检车的动力学性能,开展了轨道巡检车动力学数值仿真;轮轨接触采用非椭圆多点接触Kik-Piotrowski算法模拟,车辆系统建模过程中考虑悬挂力元非线性与轮轨接触几何非线性特性等因素,同时考虑车载设备参振影响;针对车轮踏面表面包裹高硬度聚氨酯的特殊结构,利用有限元软件ABAQUS建立了轮轨局部接触模型,采用Mooney-Rivlin橡胶模型模拟了聚氨酯特殊性质,计算了轮轨等效接触刚度;根据有限元计算结果修正了Kik-Piotrowski算法中的相关参数;基于Craig-Bampton模态综合法和多体动力学软件UM建立了车辆-轨道刚柔耦合模型;为验证仿真模型的准确性,开展了实车动力学试验;重点分析了直线和300 m小半径曲线,运行速度10~30 km·h-1工况下巡检车的振动响应。研究结果表明:车辆正常运行时,中间视觉模块垂向最大加速度大于左侧视觉模块垂向最大加速度,横向最大加速度小于左侧视觉模块横向最大加速度,车架最大加速度大于视觉模块最大加速度;车架中部易产生垂向弯曲变形,和视觉模块安装位置有胶垫减振有关;轨道巡检车在直线和300 m小半径区间运行性能整体良好,其中车辆在300 m小半径曲线段内30 km·h-1运行时,轮重减载率最大可达0.92,车架部位振动响应较大,为保证车载设备的安全性和避免车辆脱轨的风险,建议曲线段内检测速度控制在20 km·h-1左右。      

状态维修系统的故障检测诊断策略

系统有2种工作状态(正常状态、异常状态)和一种故障状态。当系统开始正常状态后,每隔一段随机时间对它检测诊断一次,直到系统故障或检测诊断出系统处于异常状态为止,诊断结果可能有误。在系统的寿命为连续型随机变量,检测间隔时间服从指数分布等假设下,利用概率分析和补充变量方法求出了系统的运行指标和稳态收益率的明显表达式。比较最优检测诊断策略下的稳态收益率和不检测诊断时的稳态收益率得到最优检测诊断策略的可行性判别准则。数值实例研究表明,研究结果可提高系统经济效益。     

凯美瑞汽车发动机故障灯亮的故障排除案例分析

针对一辆丰田凯关瑞汽车行驶中出现发动机故障灯点亮的情况，结合电控系统的工作原理，查找故障成因，最后发现是加装的摄像头品质不良所致。通过该案例说明了在对汽车电控系统具体故障诊断的过程中，需要掌握扎实的基础理论知识。了解系统的结构和工作原理，学习先进的控制技术和修理方法，同时要合理运用诊断工具和检测设备，借助电路图以及维修手册等资料，详细分析故障原因，然后进行故障排除。     

输油泵机组状态监测分析诊断系统的设计

介绍了一个输油泵机组状态监测分析诊断系统, 研制该系统的目的是为了实时掌握输油泵机组的运行状态, 为针对性的维护提供依据和手段． 文中阐述了系统的构成, 各参量监测原理,着重讨论了状态监测分析诊断系统软件的设计和系统的实施． 系统软件基于 Ｗｉｎｄｏｗｓ Ｎ Ｔ 网络平台, 具有友好的图形用户界面, 实现了数据动态显示、事故自动报警、定时报表打印、领域专门知识帮助与故障诊断等多项功能．     

An Active Endoscopy Robotic System for Direct Tracheal Inspection

The development of active endoscopy techniques is one important area of medical robot.This paper designed a new flexible and active endoscopy robotic system for direct tracheal inspection.The mobile mechanism of the robot is based on the inchworm movement actuated by pneumatic rubber actuator.There are five air chambers controlled independently,by adjusting pressures in air chambers,the robot can move in a straight mode or in a bending mode.The inspection sensors and some therapy surgery tools can be equipped in the front of the robot.The prototype was made and its mechanical characteristics were analyzed.The robot could move smoothly in a small plastic tube,and the robot is respectable to be used for inspection in human trachea directly.     

基于Monte Carlo仿真的地铁车辆系统可靠性研究

论文在地铁车辆系统失效模式与影响分析（FMECA）的基础上,考虑到地铁车辆系统故障率较低,故障状态枚举方法难以获得精确的随机状态,故运用蒙特卡洛（Monte Carlo）改进算法模拟仿真了地铁车辆系统设备单元发生故障的实际过程,并给出仿真的一般求解方法．针对地铁车辆系统故障模式及故障持续时间,构建了其可靠性的评估指标,应用实例数据进行了分析计算,得出了稳态下的系统可靠性结果．研究成果对地铁车辆运营及维修管理均具有一定的参考价值．     

微分等价递归算法在结构体系可靠度分析中的应用

利用等价线性失效模式代替两个失效模式的交集,将复杂的高维积分简化为一维积分代数运算问题,大大降低了计算量,推导了等价线性失效模式的解析表达式,提高了等价失效模式的精度,并展示了微分等价递归算法在系统功能函数的重构、体系失效模式识别和体系失效概率的计算等方面的应用,算例结果表明,该方法可以为结构体系可靠度分析提供有效手段．