【作者】 蔡景；

【导师】 左洪福；

【作者基本信息】 南京航空航天大学 ， 载运工具运用工程， 2007， 博士

【摘要】 随着科学技术的发展,民机性能和技术复杂度的不断提高,民机维修费用已经占到购买价格的三分之二,直接运营成本的10%~20%。而维修费用的高低与维修规划的合理与否有着密不可分的关系。民机维修规划包括系统、结构、区域、闪电/高强度辐射场防护四部分,系统部分的维修规划(简称系统维修规划)作为其中最主要的部分,民机制造商和航空公司都对其给予了极大的关注。系统维修规划的最终目标是合理确定系统各部件的维修任务,鉴于目前主要凭借经验进行民机系统维修规划的不足,本文建立了以维修优化模型为基础的民机系统维修规划方法。其中,针对单部件维修优化模型不能完全满足系统维修规划要求的现实,从多部件维修优化的角度出发,对民机系统维修中亟待解决的备用系统维修优化、并联系统维修优化、单元体系统的维修优化、系统维修方案的制定等问题进行了深入研究。在上述研究的基础上,根据MSG-3维修思想,开发了我国首个用于民机系统维修规划的决策支持辅助系统(MPAS)。本论文的主要研究内容如下:(1)备用系统是在主系统发生故障的紧急情况下,用于替代主系统的功能或消除、减少主系统故障带来的影响,因此具有非常重要的作用。由于备用系统长期处于非工作状态,所以其故障具有隐蔽性,本文针对隐蔽故障是否具有延迟性的特点,分别提出了不等间隔的使用检查和功能检测策略。在此基础上,考虑了主系统的故障率对备用系统维修优化的影响,以可用度为约束、期望维修费用率为目标函数,建立了备用系统的维修优化模型,该优化模型更具合理性。(2)为了提高系统的可靠度,并联技术在民机系统上被广泛地采用。针对两部件并联系统中的两冗余部件在物理性能、工作环境等方面的相似性以及检测时存在不完备的特点,提出了不完备交叉检测策略。为此,分析了冗余部件之间的故障相关形式和故障影响模式,研究了并联系统在此策略下的不同更新情况和相应的更新概率,以检测间隔和检测次数为优化变量、可靠度为约束、期望维修费用率为目标函数,建立了并联系统的维修优化模型,该优化模型更加符合实际情况。(3)单元体系统中某个部件发生故障时,通常会利用对故障部件维修的机会,对系统中短期内需要维修的其它部件,同时进行预防性维修,以达到节约系统维修费用的目的。本文针对具有这一特点的单元体系统,提出采用机会维修策略,策略中考虑了实际维修中的最小维修,以及部件不同故障类型采用不同维修等级的情况。为此,引入更新过程理论对系统中各部件的机会维修概率密度和更新过程进行了研究,并以机会维修役龄为优化变量、期望维修费用率为目标函数,建立了单元体系统的机会维修优化模型。该模型为单元体系统的机会维修役龄的确定提供了理论方法。(4)针对民机系统部分维修任务多、费用高、维修间隔差别大的特点,基于间接成组维修策略,提出了民机系统维修方案的制定方法。首先,结合民机运营和维修的特点,分析了民机系统中各类型维修任务费用;然后,研究了成组维修对民机系统整体维修费用率及利用率的影响;最后,以基本定检间隔和各部件维修任务间隔为优化变量、民机利用率和可靠度为约束、维修费用最小化为目标函数,建立了民机系统维修任务的优化成组模型。该方法为民机系统制造商制定维修计划文件,航空公司制定维修方案提供了理论支持。(5)针对民机系统维修规划难度大、任务重以及重复性强的特点,从飞机制造商和航空公司的实际需求出发,根据MSG-3维修思想目标、内容和程序,运用决策支持系统的理论和方法,以维修优化模型为基础,开发了我国首个用于民机系统维修规划的MPAS。该系统已经正式交付中航商用飞机有限公司、中航第一飞机设计院和ARJ21飞机的主要系统供应商在制订ARJ21飞机维修大纲中使用,应用效果良好。更多还原

【Abstract】 With science and technology developing further and further, the performance and complexity of civil aircrafts are increasing more and more. The maintenance cost of a civil aircraft has grown up to two thirds of the purchase price and 10%-20% of the direct operating cost. The maintain cost has a direct connection with maintenance program, therefore both aircraft manufactures and airlines have paid much attention on maintenance program. The final intention of maintenance program is to design the maintenance tasks of the civil aircraft reasonably. However the maintenance optimal models about the single-unit are more and more perfect and do not fulfill an accurate need for maintenance program. So from the point of the multi-unit maintenance optimization, this dissertation has a deep research on standby system, parallel system, task-group and opportunity maintenance. Then, maintenance program aided system (MPAS) for commercial aircraft maintenance program is developed. The main contain includes as follow:(1) The standby system is to eliminate or relieve abnormal conditions that follow a failure and take over from a function that has failed, so it is very important for the system. The standby system always works at shut-down condition, so its failure is hiden. The operational check policy and functional inspection policy with variant intervals are respectively proposed, according to whether the failure has the characteristics of delay-time. The influence of the protected system on maintenance decision for standby system is analyzed. Then the maintenance optimal model is developed to minimize the maintenance cost rate with the constrain of the availability. Thus the model gets more reasonable.(2) The parallel system is widely used in the civil aircraft in order to enhance the reliability. The redundancy units work together in the two-unit parallel system. The redundancy units have the same physical character and circumstance, and (the failures are found inconveniently), so the imperfect staggered inspection is proposed. Then the failure dependency and modes between these two units are analyzed, and the renewal probability of the parallel system is studied. At last, choosing the inspection interval and number as optimized variables, the maintenance optimal model is developed to minimize the maintenance cost rate with the constrain of the availability. So the maintenance model is more logical.(3) In module systems, opportunistic maintenance on one unit basically refers to the situation in which preventive maintenance on the other units can be carried out at opportunities. Opportunistic maintenance is useful for saving maintenance cost. The opportunistic maintenance policy is proposed considering the minimal maintenance and the different type of failure adopting different type of maintenance. Then, using the renewal theory, the probability density function of opportunity maintenance and the renewal process are analyzed. At last, the optimal maintenance model is developed to minimize the maintenance cost rate, which offers a new method for determining the age of opportunistic maintenance.(4) Because of plenty of tasks and high maintenance cost in aircraft maintenance, the task-group is important in maintenance program. As the existing method of task-group is defective, the new method of task-group is proposed based on group maintenance policy. Considering the real condition of the airlines operation, the influence of task-group on utilization and maintenance cost of the civil aircraft is researched. The optimal maintenance model is developed to minimize the maintenance cost rate, and the model is subject to the reliability and utilization. So it offers a new method of task-group for aircraft manufactures and airlines.(5) MPAS is designed based on the practical requirement of the airlines and the MSG-3. The MPAS applies the theory of decision-making support system and optimal maintenance models. Now, we have handed over this MPAS to ACAC (Avici Commercial Aircraft Co.), and it is of great application.更多还原