一种模具预防性维修策略的研究与应用

为了有效降低因为模具故障而造成的损失，提出了一种针对冲压模具预防性维修的不等间距检查双策略模型。根据历史记录拟合出模具使用寿命的概率密度函数曲线，以平均费用最小为目标寻优，得到最优的检查方案以及模具的预防性维修周期。所得的结果与实际生产情况相符合，对生产有实际指导意义。     

参数对预防性维修模型的影响分析与仿真

为了给可修部件预防性维修提供科学合理的理论依据,基于随机理论中的连续时间马尔科夫过程,建立了可修部件的预防性维修模型,分析和仿真了预防性维修模型中的维修率及检查率变化对模型稳态值影响。基于可修部件的预防性维修模型,也就是其状态转移图,计算出预防性维修模型的稳态值,分析检查率及维修率对稳态值影响,得出维修率及检查率对可修部件预防性维修模型影响的理论依据。最后借助Matlab软件对所分析出的结果进行了仿真验证。结果表明,理论分析与仿真结果是一致的。明白参数对可修部件预防性维修模型稳态值的影响对正确的选取参数,从而对获得期望的稳态值有一定的帮助。     

基于故障率修正参数的生产设备预防性维修研究

点检定修制是生产设备预防性维修的1种重要方法,是全员、全过程对设备进行动态管理的1种设备管理方法。点检定修制的核心是确定点检周期,即预防性维修周期。为此引入故障率修正参数,建立了基于单位时间净生产效益的生产设备预防性维修模型,并通过仿真的方法确立最佳预防性维修周期和维修次数,阐述了维修程度的不同对预防性维修周期的影响以及预防性维修对企业增加利润的重要性。结果表明,选择合理的故障率修正参数可以有效降低故障率,增大平均单位产值,从而为管理者制定有效的维修计划提供决策。     

基于仿真的生产设备预防性维修周期研究

为了对生产系统中的设备故障加以有效的控制，从而减少设备故障的发生，文章对生产设备的预防性维修周期问题进行了研究。通过建立生产设备预防性维修的费用模型，利用仿真的方法对不同维修策略的预防性维修周期进行优化选择。该模型综合考虑了修复性维修成本、预防性维修成本和生产损失成本。最后以故障分布形式为威布尔分布的设备为例进行仿真实验，得出设备最优维修周期结果，并阐述了经济原则对预防性维修周期的影响。     

二维产品二维预防性维修间隔期优化研究

针对故障受日历时间与使用时间共同影响的二维产品,传统的一维预防性维修已不能满足实际需求,鉴于此,本文创新性的提出了二维预防性维修的概念,以日历时间与使用时间对二维产品进行维修决策。首先建立二维产品故障率函数表达式,对二维预防性维修的过程进行具体的分析,然后以单位时间费用最小为约束目标,建立了无限使用期二维预防性维修模型,提出了最佳二维预防性维修间隔期,并通过实例对比分析了该模型的适用性与有效性,最后对未来的二维维修提出了展望。     

基于可用度分析的故障检查间隔期的确定

为了解决由于检查和维修引起的停机时间不能忽略的情况,文章分析了产品的多种检查维修的情况,并应用预防性维修理论,建立了故障检查模型。通过应用此故障检查模型,期望得到最大可用度,以及在此可用度下的维修检查间隔期,从而达到预计的故障检查目标,实现对故障检查间隔期的优化。通过算例分析,在求得最大可用度的情况下,提出了可行的故障检查间隔期,证明了该模型的实用性和有效性。     

两部件系统视情维修与生产调度的联合优化模型

为了解决生产调度过程中由系统维护维修产生的资源闲置和时间成本增加问题,将系统维修与生产调度联合建模.在众多学者将系统作为整体进行生产调度与维修研究的基础上,考虑系统内各组成部件之间的复杂关系.针对具有经济相关性的两部件系统,以调度作业加工顺序、预防性维修阈值、机会维修阈值作为决策变量,考虑到两部件同时维修比单部件独立维修更为经济,将机会维修引入到建模之中,制订机会维修、预防性维修、故障后更换的视情维修与生产调度结合的联合策略,通过劣化状态空间划分法给出生产调度过程中所有维修组合及其对应维修概率,推导出联合概率密度函数,建立以最小化总加权期望完成时间为目标的联合优化模型.通过数值实验和灵敏度分析验证所提出的策略及模型的有效性.     

基于大数据的电力企业资产组维修策略优化研究

汇总过去若干年的电力设备故障数据,运用大数据分析方法,把故障预测技术引入到预防性维修的实践中,提出一种基于大数据的预防性维修策略。首先,根据由状态检测信息得到剩余寿命的预测结果,以预防性维修时的剩余寿命为阀值制定预防性维修策略。然后,根据更新过程理论,建立以电力设备的预防性维修阀值和预测间隔期为优化变量,综合考虑电力设备维修成本、客户满意度、电量销售、停电损失、维修时机选择等约束条件呢,以电力设备平均维修费用最小和电力设备可用度最大为优化目标的预防性维修优化模型。采用人群搜索算法进行优化求解,得到系统最佳的预防性维修阀值和维修预测间隔期。最后,通过引入算例,对所建模型优化仿真求解,得到电力设备最佳的预测周期,在保证电力设备可用度的同时,使电力设备的平均维修费用最小,验证了所建模型的可行性和有效性,从而提高电力企业的整体效益。     

基本作战单元预防性维修保障过程建模仿真

为分析评价基本作战单元预防性维修保障方案,计算分析预防性维修时间,根据系统工程建模思想描述了基本作战单元的预防性维修过程,提出了故障发生比、更换比和报废比参数,建立了仿真模型,并根据Monte Carlo仿真原理给出仿真算法,为型号工作人员和装备使用人员进行保障性分析提供了理论方法和技术手段,最后以某型飞机组成的基本作战单元为例,对其预防性维修保障方案进行仿真试验验证,分析了预防性维修过程的改进对保障资源和维修时间的影响.     

基于二阶段时间延迟的多产品生产系统生产与维修联合优化研究

针对多产品生产部件串联系统的生产和维修问题进行了研究,提出了基于二阶段时间延迟的联合优化模型。首先,基于生产周期分段理论,将整个周期等分成若干单位时间段,生产与维修共用每段时间,且若干时间段后采取一次预防维修。其次,考虑生产系统的实际生产时间、可用生产时间和维修耗费时间,建立了生产计划与维修计划总成本模型。其中,维修计划考虑缺陷和故障维修费用、维修检查费用,以及非正常状态下设备运行可能产生的不合格产品损失费用;生产计划考虑生产成本、库存成本、延期未交货成本和维修停机后恢复生产的设备启动成本。最后,通过算例分析,计算最优预防维修周期和各单位时间段各产品产量,验证了模型的有效性。     

Two-stage Maintenance of a Production System with Exponentially Distributed On- and Off-periods

We consider an on–off production system which is subject to failure during on-periods. In case of a failure, the production system is maintained correctively. In addition, preventive maintenance is carried out to prevent failures. The costs of both preventive and corrective maintenance are modelled in terms of the net down-time of the production system, that is, the time that the system is not available when needed for production. Since preventive maintenance can be planned during off-periods, there is a perspective of significant savings if some freedom is built in concerning the starting time of preventive maintenance. Therefore, a two-stage maintenance policy is considered, which—in a first stage—provides the maintenance manager with a finite interval during which preventive maintenance must be carried out, and—in a second stage—determines the optimal starting time for preventive maintenance within this interval. Computational results offer useful insights, and indicate that significant savings can be achieved in comparison with a classical age maintenance policy.     

Preventive maintenance scheduling for repairable system with deterioration

Maintenance as an important part in manufacturing system can keep equipment in good condition. Many maintenance policies help to decrease the unexpected failures and reduce high operational cost such as conventional preventive maintenance. But these conventional preventive maintenance policies have the same time interval T that may easily neglect system’s reliability, because the system deteriorates with increased usage and age. Hence, this study has developed a reliability-centred sequential preventive maintenance model for monitored repairable deteriorating system. It is supposed that system’s reliability could be monitored continuously and perfectly, whenever it reaches the threshold R, the imperfect repair must be performed to restore the system. In this model, system’s failure rate function and operational cost are both considered by the effect of system’s corresponding condition, which helps to decide the optimal reliability threshold R and preventive maintenance cycle number. Finally, through case study, the simulation results show that the improved sequential preventive maintenance policy is more practical and efficient.     

基于服务性能合同模式下单部件系统视情维修策略研究

针对供应商系统维修的低效率以及维修成本参数较难获得的问题,提出了基于服务性能合同模式(PBC)下的单部件系统最优视情维修策略模型。首先,基于Gamma分布,描述单部件系统连续递增的退化过程,依据系统实时检测状态与预防维修阈值、故障阈值之间的关系,实施不同的维修策略;其次,分析单位更新周期内的检测次数和使故障设备恢复如新的维修方式,以供应商利润率最大化为目标函数,以最佳维修阈值与检测间隔时间为决策变量,建立以利润为中心的视情维修优化模型;最后,利用改进灰狼算法求解数学模型,通过算例验证所提出模型的有效性,并进行了各维修费用参数对目标函数以及最优维修策略的灵敏度分析。     

区间数可重入混合流水车间调度与预维护协同优化

针对加工时间不确定的可重入混合流水车间调度与预维护协同优化问题,构建以区间最大完工时间、区间总碳排放和区间总预维护费用为优化目标的集成调度模型.针对问题特性,通过设计改进的可能度计算方法,定义区间意义下解的Pareto占优关系.提出一种改进的离散鲸鱼群算法,通过同步调度与维护策略,实现制造与维护的联合优化;设计个体间距离计算策略,寻找“最近较优个体”;设计个体位置移动策略以及多邻域搜索策略,有效地平衡全局搜索和局部搜索,提高收敛精度.通过大量的仿真实验和结果对比分析,表明了所提出的算法对于求解区间数可重入混合流水车间调度和预维护协同优化问题的有效性和可行性.     

考虑中间库存缓冲区的设备不完美预防维修策略研究

针对带有库存缓冲区的设备维修问题,提出了随机故障设备的不完美预防维修策略。首先,考虑设备随机故障率随故障次数的增多而变大的情况,基于准更新过程,建立随机故障设备的故障次数表达式。其次,结合设备故障次数表达式,综合考虑维修成本和库存缓冲成本的基础上,构建了设备生产成本模型,以缓冲库存量和预防维修周期为自变量,以生产成本为目标函数。获得设备的最优维修策略和最佳库存缓冲量。最后,通过算例分析验证了模型的有效性,为生产线设计的可行性提供了依据。     

A generalized sequential preventive maintenance policy for repairable systems with general random minimal repair costs

A generalized sequential preventive maintenance (PM) policy for repairable systems with general random minimal repair costs is proposed and analysed. After each (planned or unplanned) preventive maintenance, the system has a different failure distribution and the failure rate function increases with the number of preventive maintenances carried out. The criterion for the optimal policy is to minimize the expected cost per unit time for an infinite time span. It is shown that under certain reasonable assumptions, sequential preventive maintenance policy has unique solutions. Various special cases are considered.     

A methodology for joint optimization for maintenance planning, process quality and production scheduling

Performance of a manufacturing system depends significantly on the shop floor performance. Traditionally, shop floor operational policies concerning maintenance scheduling, quality control and production scheduling have been considered and optimized independently. However, these three aspects of operations planning do have an interaction effect on each other and hence need to be considered jointly for improving the system performance. In this paper, a model is developed for joint optimization of these three aspects in a manufacturing system. First, a model has been developed for integrating maintenance scheduling and process quality control policy decisions. It provided an optimal preventive maintenance interval and control chart parameters that minimize expected cost per unit time. Subsequently, the optimal preventive maintenance interval is integrated with the production schedule in order to determine the optimal batch sequence that will minimize penalty-cost incurred due to schedule delay. An example is presented to illustrate the proposed model. It also compares the system performance employing the proposed integrated approach with that obtained by considering maintenance, quality and production scheduling independently. Substantial economic benefits are seen in the joint optimization.     

基于ActiveX技术的RCM维修间隔期分析软件设计与实现

基于装备综合保障工作平台总体框架,分析了RCM分析工具的功能需求与约束。应用ActiveX技术开发了RCM维修间隔期分析软件,用于分析各种预防性维修工作类型的安全性、任务性和经济性效果,实现了与装备综合保障工作平台的无缝集成。