基于遗传算法的航材库存控制优化模型

航材备件库存优化是航空公司减少资金占用、增加经济效益的关键问题,常见的方法大都采用线性规划建模,且缺乏对航材整体保障率的综合考虑。针对上述问题,文中以高价周转件为对象,从航材保障率的基本定义出发,建立了一个既考虑航材总体保障率,又考虑航材总体占用资金较少的线性规划模型,并采用遗传算法对该模型求解。结果表明,在不降低航材整体保障率的前提下,和波音公司首期备件清单推荐的备件数相比,文中的模型无论是在备件数量还是在备件占用资金总量上,都有大幅度降低。     

飞机服务备件供应保障的仿真优化

飞机服务备件不仅种类繁多而且服务需求难以预估,服务备件库存配置直接影响到飞机可用度及保障费用。飞机制造单位备件优化问题的目标是降低非计划备件需求造成的额外损失、缩短备件供应延迟时间以提高飞机的战备完好率。通过对供应保障业务流程进行扩展,采用仿真方法实现备件库存配置优化,避免了解析方法的复杂性并且易于扩展和使用,具有良好的应用性。     

航材库存系统鲁棒方差控制

为实现民航飞机航材库存科学管理,将鲁棒控制理论与实际维修航材管理相结合,把“维修生产-库存-航材补充”系统看作一个广义物理系统,使用LMI鲁棒方差控制理论解决库存优化问题.针对实际轮胎库存建立了与LMI理论相应的系统模型;使用Matlab工具完成了库存鲁棒方差控制仿真研究.结合航空公司实际航材损耗过程中存在的不确定性,...     

备件消耗预测仿真方法研究

准确的备件消耗预测是合理有效地进行备件保障各项工作的基础。在综合分析考虑备件消耗影响因素的基础上，对部件的使用寿命过程进行了仿真，建立了备件消耗仿真预测模型，实例计算了未来一定时间段内的备件消耗量，并与解析法、移动算术平均模型、灰色区间预测模型、平稳过程模型和最小二乘法等方法的预测结果进行了分析比较。实验结果表明：使用仿真方法预测备件消耗量能更真实地反映备件消耗实际情况，并且能够为备件的需求供应提供更大限度的保障，提高备件保障率。     

面向任务的某型两栖装甲装备备件配置优化模型

为提高两栖装甲装备备件保障效率,论文对携行备件配置优化问题进行研究.考虑备件单个部件价格、部件保障率和部件可更换性等因素,建立分别以保障费用和整体保障率为约束条件的配置优化模型.论文对每个备件从故障率、可更换性和的重要性三个方面进行权重值分配.结合历史经验数据及系列计算求取权重值.根据目标函数形式不同采用对目标函数进行搜索和对目标函数进行转换两种方法,分别对模型一和模型二求取最优解.最后以某两栖装甲部队濒海训练红蓝对抗演习任务为例,分别计算不同约束条件下的保障率进行比对,验证了模型的有效性.     

飞机液压系统库存备件综合保障决策方法

飞机液压系统库存备件综合保障过程存在大量不确定性,使其库存备件保障决策困难。以离散型概率序列运算理论为基础,创建了飞机液压系统库存备件综合保障决策模型。本文将飞机液压系统备件需求、维修、存储的数量看作一维离散的随机变量,并运用离散型概率序列之间的交积、卷差、卷和运算来分析保障决策过程中各随机事件之间的相互作用,从而对飞机液压系统库存备件综合保障过程进行动态描述。通过离散型概率序列运算理论制订了备件保障满足率,来预测飞机液压系统库存备件保障的时机和数量,从而为飞机液压系统库存备件综合保障提供最优的决策依据。试验结果表明,采用所建模型对飞机液压系统库存备件进行综合保障,所得结果与库存备件实际需求状况相符。该方法也可应用于航空航天及其他领域的库存备件保障决策,具有很好的工程应用前景。     

基于Flexsim仿真技术的航空关键备件存储问题研究

通过在Flexsim中建立航空关键备件存储仿真模型,结合仿真实验的结果,根据设计的维修地点平均等待率指标和储备点可提供航空关键备件的概率指标,研究了某类航空关键备件的库存控制问题。仿真结果验证了模型的有效性。     

交通装备售后绩效保障系统控制策略研究

针对装备售后保障逐渐向绩效保障模式转变的趋势.文章研究绩效模式下的交通装备售后保障系统控制策略,分析部件损耗特征并给出不同模拟情境下的最优控制策略;首先,从仓库备件库存出发推导出备件库存水平状态概率分布,并获得如可用度等系统绩效性能指标,然后,建立绩效约束的保障系统优化模型并设计出有效的遗传算法;最后,进行数值实验;结果表明,平均故障间隔时间对保障系统控制策略的影响大,而备件可修复率对保障系统控制策略的影响较小。     

机载通信电台通电老炼检测系统设计与实现

为保证航材备件的完好率，解决仓储机载通信电台长期不通电导致的装备性能下降甚至出现故障的问题，综合运用自动测试、虚拟仪器、面向信号设计等技术，以计算机为核心，以PXI仪器、GPIB仪器为依托，以多种总线接口为纽带，构建了一种可靠性高、通用性好、操作简便、可扩展性强的自动化通电老炼平台。通过在航材仓库中使用，证明该电台老炼检测系统降低了仓储通信电台的失效率，提高了仓储电台的完好率。     

基于物理规划的航空保障多目标优化模型

根据作战需求确定优化权衡目标,以使用保障需求和技术可行性为约束条件,以保障能力指标集合,以备件储备量的组合为决策变量,建立多个单目标优化模型和多目标优化模型,提出了基于物理规划的航空保障能力多目标优化方法,结合粒子群算法得到了满足设计者偏好的最佳航材备件方案.设计了航空保障能力系数的满意等级,构造了各优化目标的偏好函数和综合偏好函数,使整个设计过程更加灵活地反映决策者偏好,减轻大规模多目标设计问题的计算负担,使军用机群的保障能力更适合实际作战要求,同时通过对比单目标优化的结果,验证了算法的有效性.     

基于HTCPN的飞机维修保障过程建模与仿真

飞机维修保障过程模型是研究飞机维修保障系统结构与运行的基础,是典型的离散系统,层次赋时着色Petri网（HTCPN）有多种优点,是描述飞机维修保障过程的有力工具。论文介绍了HTCPN的建模方法,分析了飞机的维修保障过程,在CPNTools平台上,建立了基于HTCPN的飞机维修保障过程模型,并对模型进行了仿真,给出了分析结果,为研究飞机的维修保障提供了参考,为优化飞机维修过程、合理配置资源提供了依据。     

国产民机数字化运营流程管理及仿真系统

数字化运营支持对国际民机领先制造商提高自身市场竞争力、扩大经济效益起到了越来越重要的作用。深入调研国内外数字化运营支持先进技术、经验和发展趋势,针对现有机型ARJ21和C919,梳理了国产数字化运营支持的八大业务场景,重构适合国产民机发展规律的数字化运营支持业务流程。充分考虑数字化、信息化技术发展以及运营支持需求的变化,以及成果的实用性,基于BPMN2.0业务流程建模符号标准和Activiti5流程引擎,搭建业务流程管理及仿真系统,对国产民机数字化运营支持业务流程进行电子化管理,并对典型的维修任务分析作业方法业务流程进行仿真。     

Computing small-fleet aircraft availabilities including redundancy and spares

Logistics support is a key element of aircraft transportation systems. This paper is concerned with the impact of aircraft spares provisioning decisions on the availability of aircraft. Spares provisioning in this context is complicated by the fact that spares may be shared across aircraft and that aircraft may have redundant systems. In addition, decisions concerning aircraft spares support require a rapid response for safety reasons. Analytical models have proven to provide a quicker response time than corresponding simulation models. There is an existing analytical model that includes the effect of redundancy and spares, but the underlying assumption is that a large number of aircraft are being modeled. In many applications, predictions of the number of times an aircraft can fly each day and the number of aircraft that are ready at any time are applied to a small fleet of aircraft. This paper demonstrates the improvement in computational accuracy that is achieved by reflecting the impact of small numbers of aircraft on availability projections. The approach used is to extend existing finite queuing spares models to including redundancy. Further, the method is used to optimize spares provision with respect to a user specified availability goal. Although the case study for this work is a military combat aircraft application from the Gulf War, the method is applicable to any small system of vehicles or machines where components may be redundant, demand and repairs may be approximated as following an exponential distribution, and limited access to spare parts is the rule.Scope and purposeIn many situations in exploration, mining, rescue, and defense, it is necessary to dispatch a small fleet of machines to a remote area to perform an important function. Since the location is difficult to access, resupply is often difficult or impossible. In anticipation of this situation, the machines often include redundant parts to allow for some component failures in the field that do not eliminate a machine from further use. Decisions have to be made, in advance, as to which backup components (spares) should be included with the machines at the remote site to be used when failures exceed the built-in redundancy level. This turns out to be an interesting modeling problem. Since the number of machines is relatively small, exact counting of machines and their components (both redundant and spares) must be done in order to make a decision. This leads to a combinatorial problem that cannot be solved for practical-sized problems with a reasonable computational effort by, say, discrete simulation. In this paper, we develop a methodology, based on finite queuing theory, which addresses this need. It is applied and validated on an availability situation similar to the deployment of aircraft to the Middle East during the Gulf War.     

基于经济学模型的推荐系统的研究

结合经济学模型中的"可替代商品"概念提出"可互替代集",以描述项目之间的可互相替代关系.同时把博弈论中的"不完全但完美的动态博弈"模型应用到协同信息推荐系统,提出了"带上下文的推荐算法".其核心思想是把推荐过程看作是推荐系统与用户之间的动态博弈,用经典的博弈论模型描述推荐过程.     

基于地形遮蔽的飞行器暴露范围计算

研究飞行器在实战环境中的暴露范围对提升飞行器隐身作战能力,指导战前任务规划具有重要意义;提出了飞行器暴露范围和高度余量概念;建立了飞行器暴露范围模型;通过数字地图处理技术建立了地形遮蔽作用下的暴露范围模型;对雷达探测概率进行了研究,建立了探测概率模型;编写了飞行器暴露范围计算软件,能实时计算出不同方位方向上的高度余量;最后进行了实例仿真,结果表明所建模型的正确性及所编软件的有效性。     

A variable fidelity information fusion method based on radial basis function

Radial basis function (RBF) model has been widely used in complex engineering design process to replace the computational-intensive simulation models. This paper proposes a variable-fidelity metamodeling (VFM) approach based on RBF, in which different levels fidelity information can be integrated and fully exploited. In the proposed VFM approach, a RBF metamodel is constructed for the low-fidelity (LF) model as a start. Then by taking the constructed LF metamodel as a prior-knowledge and mapping the output space of the LF metamodel to that of the studied high-fidelity (HF) model, a variable fidelity (VF) metamodel is created to approximate the relationships between the design variables and corresponding output responses. A numerical illustrative example is adopted to make a detailed comparison between the VFM approach developed in this research and three existing scaling function based VFM approaches, considering different sample sizes and sample noises. Results illustrate that the proposed VFM approach outperforms the scaling function based VFM approaches both in global and local accuracy. Then the proposed VFM approach is applied to two engineering problems, modeling aerodynamic data for a three-dimensional aircraft and the prediction of weld bead profile in laser welding, to illustrate its ability in support of complex engineering design.     

飞行器故障预测与健康管理(PHM)集成工程环境研究

故障预测与健康管理(PHM)技术能够实现故障监测、诊断、预测、状态评估及综合决策的功能,能够降低飞行器维修、使用和保障费用,提高飞行器战备完好率、任务成功率以及安全性和可用性;在分析了国内外研究现状的基础上,提出了构建飞行器故障预测与综合健康管理的通用化支撵平台和验证环境的设计思路,并展开描述了PHM开发环境、运行环境、验证环境的具体功能组成,研究成果能够为检验飞行器PHM系统工作效能提供有效验证,为降低飞行器PHM验证费用提供借鉴.     

大型先进民用飞机高升力控制系统架构研究

为了支持大型民用飞机的研制发展,对典型大型先进民用飞机的高升力控制系统进行了研究,分析了其研制特点。通过对比其中的设计技术和分析最近发展的新功能,总结出了大型先进民用飞机高升力控制系统架构的发展趋势,并设计给出了一种全新的高升力控制系统架构,可以用于国内大型民用飞机研发借鉴。     

Using virtual reality technology for aircraft visual inspection training: presence and comparison studies

The aircraft maintenance industry is a complex system consisting of several interrelated human and machine components. Recognizing this, the Federal Aviation Administration (FAA) has pursued human factors related research. In the maintenance arena the research has focused on the aircraft inspection process and the aircraft inspector. Training has been identified as the primary intervention strategy to improve the quality and reliability of aircraft inspection. If training is to be successful, it is critical that we provide aircraft inspectors with appropriate training tools and environment. In response to this need, the paper outlines the development of a virtual reality (VR) system for aircraft inspection training.

VR has generated much excitement but little formal proof that it is useful. However, since VR interfaces are difficult and expensive to build, the computer graphics community needs to be able to predict which applications will benefit from VR. To address this important issue, this research measured the degree of immersion and presence felt by subjects in a virtual environment simulator. Specifically, it conducted two controlled studies using the VR system developed for visual inspection task of an aft-cargo bay at the VR Lab of Clemson University. Beyond assembling the visual inspection virtual environment, a significant goal of this project was to explore subjective presence as it affects task performance. The results of this study indicated that the system scored high on the issues related to the degree of presence felt by the subjects. As a next logical step, this study, then, compared VR to an existing PC-based aircraft inspection simulator. The results showed that the VR system was better and preferred over the PC-based training tool.     

Structure of an onboard decision making support system at the stage of passenger aircraft takeoff

A new method for controlling the aircraft takeoff process and the possibility of creation of an onboard decision making support system based on it are substantiated. Takeoff is controlled by estimation of a specially introduced function called the “effective takeoff mass”. An approach providing the formation of a criterion of making the decision on acceptability of the takeoff process and the choice of its parameters is considered. The format of presentation of the information about the takeoff process to the crew is described.