基于性能退化的数控装备维修决策研究

发布时间：2018-09-10 06:57

【摘要】：数控装备是制造业的基础装备,集成了机械、电气和信息等技术的一体化设备,其优点为精度高、效率高。同时制造业是国家工业的重要组成部分,也是技术突破和理论创新的重要领域。由于我国基础制造设备技术较为薄弱,数控装备的质量与可靠性长期存在问题。随着国家和政府在不断出台政策提高制造业的创新能力,并经过信息化、网络化和智能化革新后,数控装备的技术水平正在日益提升,但是如何保证数控装备的质量与可靠性依然是非常重要的研究课题。任何设备在投放使用后,都会不可避免地发生故障,对于数控机床这类设备而言,一旦发生故障,其后果非常严重,因此对数控机床进行维修管理是非常必要的。通过制定合理的维修策略,可以降低机床设备故障的发生频率,减少因故障造成的损失。维修包括计划和非计划的操作以保持系统或使它恢复到可接受的运行状态。维修策略的优化旨在以尽可能低的维修成本提供最佳的系统可靠性、可用性和安全性。由于系统的复杂性增加,其安全性和可靠性要求也随之提高,加之劳动力成本的上升,导致以前的维修策略无法满足企业需要,因此近年来强调了适当的维修策略。论文主要研究内容包括以下几个方面:1.本文以数控机床刀具为研究对象,围绕性能退化展开刀具的可靠性建模,研究的主要工作有:首先对机床的刀具进行可靠性分析,分别利用退化轨迹方法和退化方法对刀具的侧面磨损量进行可靠性评估以此为基础,分析研究了刀具的退化机理及其性能状态转移过程,为后续的维修决策提供研究基础。2.建立二态元件的数控机床选择性维修模型,利用改善因子模型建立维修费用与系统可靠度之间的函数关系,在此基础上,以机床的任务完成率为目标函数,维修费用为约束条件,对机床的维修策略进行优化,得到有限维修资源下数控机床的最佳维修策略。3.建立多态元件的数控机床选择性维修模型,将机床的功能部件划分为有限个离散的性能率状态,利用各个子系统的状态转移强度矩阵确定下一个任务结束后的状态转移概率,通过通用生成函数递归到系统的任务完成率以及维修总费用,并获得两种不同维修费用下的最佳维修策略。
[Abstract]:Numerical control equipment is the basic equipment of manufacturing industry. It integrates mechanical, electrical and information technology. It has the advantages of high precision and high efficiency. At the same time, manufacturing industry is an important part of national industry, and also an important field of technological breakthrough and theoretical innovation. Because of the weakness of basic manufacturing equipment technology in our country, the quality and reliability of numerical control equipment have existed problems for a long time. As the government and the state continue to introduce policies to improve the innovation capability of the manufacturing industry, and through information technology, networking and intelligent innovation, the technological level of CNC equipment is increasing day by day. However, how to ensure the quality and reliability of CNC equipment is still a very important research topic. Any equipment will inevitably fail after putting into use. For such equipment such as numerical control machine tools, once the failure occurs, its consequences are very serious, so it is very necessary to manage the maintenance of CNC machine tools. By making reasonable maintenance strategy, the frequency of machine tool equipment failure can be reduced, and the loss caused by the fault can be reduced. Maintenance includes planned and unscheduled operations to maintain the system or restore it to acceptable operating conditions. The optimization of maintenance strategy aims to provide optimal system reliability, availability and security at the lowest possible maintenance cost. As the complexity of the system increases, its security and reliability requirements are also increased, coupled with the rise in labor costs, leading to the previous maintenance strategy can not meet the needs of enterprises, so in recent years, the appropriate maintenance strategy has been emphasized. The main contents of this paper include the following aspects: 1. In this paper, the numerical control machine tool is taken as the research object, and the reliability modeling of the tool is carried out around the degradation of the performance. The main work of the research is as follows: firstly, the tool reliability of the machine tool is analyzed. The degradation path method and degradation method are used to evaluate the reliability of tool side wear, and the degradation mechanism and performance state transfer process are analyzed and studied, which provides the basis for further maintenance decision. The selective maintenance model of NC machine tools with two-state components is established, and the functional relationship between maintenance cost and system reliability is established by using the improvement factor model. On this basis, the task completion rate of the machine tool is taken as the objective function. The maintenance cost is the constraint condition, the maintenance strategy of the machine tool is optimized, and the optimal maintenance strategy of the NC machine tool under the limited maintenance resources is obtained. The selective maintenance model of NC machine tools with polymorphic components is established. The functional components of the machine tools are divided into finite discrete performance rate states, and the state transition probability after the end of the next task is determined by the state transfer intensity matrix of each subsystem. The task completion rate and total maintenance cost of the system are recursively obtained by general-purpose generating function, and the optimal maintenance strategies under two different maintenance costs are obtained.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG659

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