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.     

视情维修条件下舰载机的战备完好性

基于视情维修方法的维修系统是复杂的动力学系统,其不同构成要素之间的相互作用导致维修系统的动态变化。通过分析视情维修的内涵,以舰载机的战备完好性为目标,运用系统动力学（SD）方法,并应用专用软件VENSIM分析视情维修条件下舰载机维修保障系统内部各要素的反馈控制结构,建立视情维修条件下舰载机战备完好性的系统动力学模型。仿真模型的运行结果表明,将视情维修方法引入舰载机维修保障,可有效提高舰载机的战备完好性     

Core task modelling in cultural assessment: a case study in nuclear power plant maintenance

This article aims at illustrating the use of core task modelling on a system level and attempts to show its relevance to cultural assessment. The methodology that was used in a case study consists of an iterative process of core task modelling, organisational culture research and organisational assessment. The case study was conducted in a nuclear power plant's (NPP's) maintenance department. The maintenance task, its goals, critical demands and the demands for the working practices were conceptualised by core task analysis. The organisational culture of the maintenance department was explored with interviews, a survey and workgroups. The results show three critical demands and three instrumental demands to be controlled on all levels in the organisation. The maintenance culture must support the activity of balancing between these distinct requirements. The core task model was used in assessing the characteristics of the maintenance culture. This was done through analysing the unity of the personnel's conceptions concerning the organisation, its tasks, goals and values. The relevance of this approach to organisational development is discussed.     

飞机发动机导线连接关系数据库的设计与开发

针对飞机发动机导线故障维修过程中查找导线资料既费时又费力的现状,基于Visual Basic.NET建立了飞机发动机导线连接关系数据库.该数据库简单实用,从而极大地提高了机务人员的排故工作效率,缩短了故障诊断及维修时间,提高了飞机维修的质量,给专业飞机导线故障维修人员提供了有力的支持.     

装配序列约束下的飞机虚拟维修过程建模仿真

针对当前飞机虚拟维修过程模型固化,对维修复杂行为关系缺乏考虑,无法满足学员多样性实训需求的现状,充分考虑了飞机系统的复杂度、学员操作的不规范性和随机性等因素,依据各维修装配序列间的优先约束关系,构建了优先约束矩阵,进而定义了优先约束时间有色Petri网模型。在系统梳理维修实体及其维修操作行为的基础上,提出了虚拟维修实体操作元模型和元模型融合下的过程建模,阐述了基于优先约束时间有色Petri网的动态虚拟维修过程实现方法。最后,以A320飞机加油活门的某一个随机拆卸过程为例,进行建模仿真,验证了模型的有效性。     

Unsafe acts and unsafe outcomes in aircraft maintenance

Road safety studies using the Driver Behaviour Questionnaire (DBQ) have provided support for a three-way distinction between violations, skill-based errors and mistakes, and have indicated that a tendency to commit driving violations is associated with an increased risk of accident involvement. The aims of this study were to examine whether the three-way distinction of unsafe acts is applicable in the context of aircraft maintenance, and whether involvement in maintenance safety occurrences can be predicted on the basis of self-reported unsafe acts. A Maintenance Behaviour Questionnaire (MBQ) was developed to explore patterns of unsafe acts committed by aircraft maintenance mechanics. The MBQ was completed anonymously by over 1300 Australian aviation mechanics, who also provided information on their involvement in workplace accidents and incidents. Four factors were identified: routine violations, skill-based errors, mistakes and exceptional violations. Violations and mistakes were related significantly to the occurrence of incidents that jeopardized the quality of aircraft maintenance, but were not related to workplace injuries. Skill-based errors, while not related to work quality incidents, were related to workplace injuries. The results are consistent with the three-way typology of unsafe acts described by Reason et al. (1990) and with the DBQ research indicating an association between self-reported violations and accidents. The current findings suggest that interventions addressed at maintenance quality incidents should take into account the role of violations and mistakes, and the factors that promote them. In contrast, interventions directed at reducing workplace injury are likely to require a focus on skill-based errors.     

Integrating hierarchical balanced scorecard with fuzzy linguistic for evaluating operating room performance in hospitals

Health care organizations are operating in a complex environment. The competitive and dynamic health care sector has spurred hospitals into delivering greater flexibility and quality of services. An efficient performance evaluation system is essential for controlling, monitoring and improving service quality in health care organizations. The performance evaluation of operating room (OR) is a useful work for managers to control the operational process of OR team so as to promote the performance. This paper explores the use of a management tool: balanced scorecard (BSC), which facilitates managers to meet multiple strategic goals, and fuzzy linguistic method for evaluating OR performance. BSC is a strategic planning and management system that is used extensively in business and industry, government and nonprofit organizations. First, a model is developed for measuring the acceptable performance of OR based on the interaction financial, customers, internal business process and learning and growth perspective. After that, BSC structure integrated with fuzzy linguistic is proposed for measuring and improving the service. The aim of this study was to build a performance evaluation system for OR and use a fuzzy linguistic to convert the subjective cognition of managers into an information entity and confirmation of improvement. This research results are able to help the organisation to evaluate and revise its strategy and generally to adopt modern management approaches in every day practise.     

基于UCLinux的分布地热空调控制器的设计及其任务调度的研究

现在绿色环保的地热空调(GSHP)应用范围越来越广,但是通常是使用PLC作为控制器的小型系统,不利于大规模应用和控制算法的实现。文章提出了一种分布式地热中央空制系统的硬软件的实现。它的硬件体系是分布式的结构,核心是“本地简单远程复杂”,它采用FUZZY+PID的控制方法。软件采用uclinux操作系统,采用基于Qos的二级层次反馈调度算法作为任务调度。实际运行结果表明,该系统在实际运行中节能效果显著。由于可以通过互联网进行监视系统的运行状态,因此维护也非常简单。     

Unsafe acts and unsafe outcomes in aircraft maintenance

Road safety studies using the Driver Behaviour Questionnaire (DBQ) have provided support for a three-way distinction between violations, skill-based errors and mistakes, and have indicated that a tendency to commit driving violations is associated with an increased risk of accident involvement. The aims of this study were to examine whether the three-way distinction of unsafe acts is applicable in the context of aircraft maintenance, and whether involvement in maintenance safety occurrences can be predicted on the basis of self-reported unsafe acts. A Maintenance Behaviour Questionnaire (MBQ) was developed to explore patterns of unsafe acts committed by aircraft maintenance mechanics. The MBQ was completed anonymously by over 1300 Australian aviation mechanics, who also provided information on their involvement in workplace accidents and incidents. Four factors were identified: routine violations, skill-based errors, mistakes and exceptional violations. Violations and mistakes were related significantly to the occurrence of incidents that jeopardized the quality of aircraft maintenance, but were not related to workplace injuries. Skill-based errors, while not related to work quality incidents, were related to workplace injuries. The results are consistent with the three-way typology of unsafe acts described by Reason et al. (1990) and with the DBQ research indicating an association between self-reported violations and accidents. The current findings suggest that interventions addressed at maintenance quality incidents should take into account the role of violations and mistakes, and the factors that promote them. In contrast, interventions directed at reducing workplace injury are likely to require a focus on skill-based errors.     

机载音频管理组件自动测试系统的设计与实现

音频管理组件是民航飞机话音通信系统的传输中枢,交联复杂,测试项目繁多,且主要机型的相关组件标准各异,造成目前该类组件的测试效率低下,人为差错率高,测试成本高昂;通过对各机型相关组件自动测试需求的分析,建立测试模型,整合测试资源,完成了基于PXI总线的多机型音频管理组件综合测试系统的设计;测试系统采用模块化结构,结合自主设计的多种测试仿真组件,通过统一的测试执行管理平台控制测试资源完成自动测试;实践证明,该系统工作稳定,完全满足多种机载音频管理组件的测试需求,并显著提高了的测试的效率和准确率。     

The scheduling of maintenance. A resource-constraints mixed integer linear programming model

The scheduling of preventive maintenance is crucial in reliability and maintenance engineering. Hundreds of parts compose complex machines that require replacement and/or repairing. Maintenance involves the machine vendor (1), the machine user (2) and the service maintenance provider (3). The vendor and the maintenance service provider have to guarantee a high level of availability and productivity of the machines and maintain their down-time at a minimum even though they are installed worldwide and usually far from the vendor’s headquarters and/or the locations of the provider’s regional service offices. Moreover, many companies have great profits from maintenance and spare parts management.This study aims to illustrate an original mixed integer linear programming (MILP) model for the cost-based, reliability-based and resource-constraints scheduling of preventive maintenance actions. The model minimizes the total cost function made of spare parts contributions, the cost of the execution of the preventive actions and the cost of the additional repair activity in case of unplanned failure. The cost of the personnel of the producer and/or the maintenance service provider is also included. Finally, the paper presents a case study in a what-if environment demonstrating the effectiveness and the novelty of this study in real and complex applications.     

基于有线传输光缆的日常维护和技术维护分析与研究

随着生活质量的提高,人们对图像、数据等传输业务的需求量不断扩大,在信息技术快速发展的同时人们开始 要求传输业务的速度和质量。因而在市场需求和技术创新的支持下,光纤传输网得到了全面的发展。与此同时,光缆通信成 为我国通信行业中的关键环节,加强有线传输光缆的日常维护和技术维护成为当务之急。本文通过分析加强有线传输光缆的 日常维护和技术维护的重要性入手,阐述当前日常维护和技术维护的具体工作,探讨当前有线传输光缆的日常维护和技术维 护的问题所在,进一步研究日常维护和技术维护的优化策略。旨在提高有线传输光缆正常运行的安全性、有效性,满足人们对 于数据业务和图像业务的各项需求,最终提高人们的生活质量。     

多目标军用飞机维修作业调度优化研究

为提升维修作业与现代战机的适应程度,对军用飞机维修作业调度模型构建与调度优化算法设计进行探讨。在沿用柔性作业车间调度问题的形式化描述构建维修作业调度模型的基础上,选取遗传算法对执行步骤进行设计,引入耦合算子重新调整工序排序部分染色体以避免染色体违背耦合约束无法解码的情况发生,并采用维修作业调度案例与Brandimarte测试数据验证多目标调度优化算法的适用性与优化性。维修作业调度模型构建与调度优化算法的探讨促进维修管理的精细化,为调度相关领域的深入研究拓宽思路。     

改进的蚁群算法在飞行路径模型中的应用

为了保障飞机安全地运行,FAA规定每架飞机在飞行一定时间后都要进行周期性检修。通常考虑到检修成本,任一种检修都要在指定的机场完成,因此要求飞机每飞行一定的小时数后都要返回到指定的维护基地进行定期检修。如何合理地进行飞机飞行路径的调度以使飞机周期性地返回指定检修机场进行检修是本文研究的关键。为了问题简化,本文主要针对单检修基地、单机型的检修路径调度问题进行研究。本文结合经典蚁群算法,对现有算法参数的设置及信息的更新等方面进行改进后应用到飞行路径模型中,并运用Matlab对该算法编程,运用具体数据进行计算实现,确保了飞机周期性返回检修机场,实现周期性检修。     

基于聚类Web服务的组合服务模式规约*

Web服务组合是提高服务质量的实用方法,但如何实施有效的服务组合一直是研究的难点。基于此,提出了一种通过建立组合服务模式规约来验证服务组合有效性的方法。依据经过聚类后各个类别服务间的关联性关系分析,首先提出组合服务模式的概念和确定其方法、原则;然后给出Web服务中组合服务模式规约;最后通过使用组合服务模式规约,应用飞机订票的实验验证了Web服务组合的有效性。     

A reference model of virtual service production networks

Virtual organisation of collaborative networks frequently demands for information and communication technology to support coordination of cross-organisational business process chains. Service-oriented software technologies provide promising means to regulate and enforce coordination of cross-organisational software service interactions but miss organisational abstractions and methodology. This paper proposes a conceptual reference model of collaborative network coordination that satisfies flexibility and agility requirements of virtual organisation by building on common software service abstractions and lifecycle methodology. In particular, the model focuses collaborative service networks and introduces the concept of virtual business service that represents business service processes as software service abstractions and supports flexible regulation and agile enforcement of their coordination by means of software service lifecycle methodology. For demonstration and evaluation purpose, we present a case study of service-oriented systems analysis for virtual organisation of a collaborative e-science network that adopts our conceptual reference model.     

AH-64D main transmission accessory drive spur gear installation fault detections

The US Army has launched an aggressive program to implement condition based maintenance on its rotary wing assets. Condition Based Maintenance takes advantage of technology developments in the areas of machinery monitoring, signal processing and fault modeling to reduce the cost of ownership through improved maintenance procedures. Documenting the reduction in maintenance burden, cost savings and increased safety through early detection of helicopter faults is an important step in justifying the program. This paper describes a novel technique used to detect a serious fault in the accessory section of the AH-64D Apache main transmission. The technique determines if the primary or secondary clutch system is driving the aircraft accessories through a tachometer speed ratio. The method has identified three aircraft operating on the secondary system allowing Army maintenance crews to replace the affected transmissions and quickly restore the aircraft to operational status.     

Using Association Aspects to Implement Organisational Contracts

The maintenance of organisation is a prerequisite for all viable systems in dynamic environments. In many living systems this organisation is, in part, achieved through coordination systems such as the nervous or endocrinic systems that can be seen as separate from the functional systems they coordinate. As software systems become more open and complex, the definition of separate organisational structures may prove a useful way to maintain their viability while managing their complexity. In this paper we show how a coordination system can be implemented as a separate concern, and posterior, to the definition of the functional system it controls and regulates. Such functional systems are loosely coupled collections of roles played by objects. We show how association-aspects can be used to create contracts that bind these roles together into an organisation. These contracts regulate the flow of control through a structure of roles in the organisation, and allow performance to be specified and monitored. These contracts also bind clusters of roles into self-managed composites — each composite with its own organiser role. The organiser roles can control, create, abrogate and reassign contracts. This ability enables organisers to reconfigure the system in response to changes in external conditions or changes in performance requirements.     

刹车控制单元便携式检测设备的设计与实现

在飞机地面试验台进行刹车试验时,或者在外场飞机起飞前进行检查、大修厂的飞机维修时,防滑刹车控制单元的性能检测设备必不可少。针对飞机预测及健康管理(PHM)提出的维修保障困难问题,于开放的、面向对象的PHM体系结构,提出了一种便携式飞机刹车系统检测设备,结合其关键系统展开设计。此设计包含了飞机PHM体系结构设计及相关环节的技术实现,并将传统测试的相关测试设备小型化轻量化,集成在一拉杆箱内,加以一体化和良好的散热设计,使得设备方便运输携带,且具有一定抗强冲击力和震动的特性,有很高的安全性、可靠性,并具备故障定位等智能化检测能力,可满足外场检测的恶劣测试环境,提高飞机检修效率。     

基于QAR数据的民航客机设计理念分析

中国国内运行着大量国外先进民用飞机。这些飞机全部装有飞行数据快速存取记录器,以采集飞行数据开展飞行品质监控工作;民机日常飞行数据除了能够在航空公司运行中发挥作用,还能够通过技术手段分析得出先进型号的设计经验与运行特点,相关技术成果对国产民机制造业的发展也具有一定的借鉴意义;在分析国内外相关研究基础上,以两款国外民机巡航段飞行数据的分析为例,解析了两型飞机的高度保持控制律设计逻辑,实际案例分析表明,基于QAR数据的分析能够有效地反应在自动飞行阶段高度保持控制律中体现的设计逻辑,从而有助于对国产民机的设计和优化。