民用飞机健康状态评估方法 

飞机健康状态评估技术能够为飞机的健康状态提供量化评价的方法和手段,通过给出量化的飞机健康指数值,可以为后续的飞机维修提决策提供必要的技术基础;在分析了健康状态评估的技术现状的基础上,对飞机整机级的健康状态评估方法进行了研究,提出了健康状态评估技术方案,并对波音AHM系统健康指数模型进行了研究;提出的民用飞机健康状态评估方法,实现了从传统的对故障的状态识别转移至对性能退化程度的检测和量化描述,其应用可以为航空公司安排飞机运营提供参考,并为合理安排计划维修提供决策支持。     

基于LSTM的风洞设备健康状态评估方法研究

针对风洞设备健康状态评估中特征提取困难、量化算法复杂等问题,提出了一种基于深度学习的健康度评估方法,利用正常状态样本数据训练LSTM编解码器网络并构建特征空间,利用测量数据特征向量与特征空间的欧氏距离衡量健康状态的退化程度,从而高效地实现了系统或设备的健康状态量化评估;经风洞试验室轴流风机转子不平衡故障、长轴轴承裂缝故障等两个数据集进行验证,取得了与设备工作状态一致的健康度评估值,具有很强的工程应用价值。     

基于逻辑框图的卫星健康评估方法

针对目前无法准确量化反映在轨卫星健康状态的问题,提出一种基于卫星部组件逻辑连接关系的健康状态分层评估模型,用任务健康度和任务风险度定量表示卫星状态。在部件层,选取关键遥测参数指标,通过统计历史健康数据及查阅设计资料建立部件级非线性无量纲评估模型;在组件层,通过各部件的逻辑连接关系分别建立评估模型;在分系统层,利用组件层得到的结果及各组件的逻辑连接关系,结合模糊层次分析（fuzzy analytic hierarchy process,FAHP）和变权理论,建立分系统健康状态评估模型。最后,通过某卫星正常运行时期和异常运行时期的在轨遥测数据验证,结果表明,该评估模型具有正确性。     

基于数据挖掘的智能配电站房运行状态评估方法

为解决智能配电站房的在线监测与预警评估问题,提出了一种基于数据挖掘的智能配电站房运行状态评估方法。首先建立配电站房多源数据信息阵列,对当前时刻之前一段时间内配电站房内部的温度信息、湿度信息、水侵信息、烟雾信息、开关遥测信息、开关遥控信息进行描述;其次通过配电站房多源数据评估阵对智能配电站房多源数据信息阵进行了量化评估;然后对配电站房多源数据评估阵进行每列量化综合以生成配电站房多源数据单项评估阵;最后基于加权平均方法对配电站房多源数据单项评估阵进行综合,生成智能配电站房运行状态评估指标。实例分析验证了本文所提方法的可行性,可满足现场工程实际需求。     

桥梁长期健康监测中状况评估专家系统的研究

本文利用桥梁健康监测的实时数据,结合状态评估理论和人工智能技术,进行武汉长江二桥桥梁健康状态评估专家系统的工程应用研究,为大桥的管理养护和维修提供科学决策具有重要的理论意义和工程实用价值。同时研究也为该领域建立实用化的桥梁健康监测智能综合评估系统提供了参考。     

基于LoRa技术的低压集抄系统运行可靠性分析

传统的低压集抄系统运行的可靠性评估方法,缺少具体的可靠性评估指标框架,无法准确地判定系统的运行状态,造成评估准确率、评估效率、评估可靠度及评估完整度较低的问题。提出基于LoRa技术的低压集抄系统运行可靠性评估方法。在LoRa的框架协议内设定系统运行可靠性的评估指标,判定该低压集抄系统的状态转移率、平稳状态概率以及元件的瞬时状态,以此判定系统的运行状态是否可靠。在此基础上,分别计算系统各个运行状态当中各个节点的负荷承载能力,以及电压崩溃风险。由此完成低压集抄系统运行可靠性评估。经实验验证：所提出的系统运行可靠性分析方法比传统方法的平均评估准确率提高了25%,且所提方法的评估效率、评估可靠度和评估完整度均高于传统方法。     

飞机液压系统健康状态综合评估技术研究

针对目前飞机液压系统健康状态难以准确评估问题,构建了一个基于灰色聚类法和熵权法相结合的飞机关键部件—液压系统两级健康状态综合评估模型。该模型首先利用熵权法对飞机液压系统各部件相关参数的权重进行计算并确定,然后利用灰色聚类法对飞机液压系统各部件进行健康状态综合评估,得到各部件的聚类系数。在此基础上,用所得各部件聚类系数构成飞机液压系统健康状态综合评估的评判矩阵,再用熵权法计算并确定飞机液压系统各部件的权重,最后利用灰色聚类法对飞机液压系统的整体健康状态进行综合评估,从而得到飞机液压系统健康状态综合评估结果。通过实例对所构建的评估模型进行试验验证。研究结果表明,所构建的健康状态评估模型能够实现飞机液压系统健康状态综合评估效能,具有良好的工程应用前景。     

基于航后QAR数据译码的APU故障诊断技术

APU系统由于其会直接影响飞机的运行安全性、经济性以及旅客的舒适度,因此无论是飞机主制造商还是航空公司都非常重视APU系统的故障诊断工作;但是,在APU设计之初又无法实现对其所有故障的准确探测和隔离;为了实现飞机投入运营后对APU系统疑难故障的探测问题,文章以B737飞机的APU启动电门故障以及APU启动时间异常为例,提出利用航后的QAR相关数据译码结果,查看相关参数的变化情况,提高APU系统的故障诊断水平;实践证明,利用航后QAR数据译码结果能够极大提高航空公司对APU系统以及飞机的故障诊断水平,方便航空公司日常的运营和维护工作,最终提高飞机的利用率。     

QAR数据的数据融合算法

分析了QAR数据中影响飞机性能衰减的主要因素,采用自适应加权数据融合算法和扩展卡尔曼滤波算法对相关性能参数进行了状态参量的估计,并验证了自适应加权融合算法在外界环境影响较小时的便捷性和外界环境影响过大时的局限性.引入扩展卡尔曼滤波算法,加入高斯噪声的计算,提高了状态估计值的精确度,为航空公司改善飞机运行提供了参考.     

基于HMM的机载设备状态健康评估方法研究

针对机载设备的状态健康评估问题,采用隐马尔科夫模型(HMM)对其进行性能退化程度的评估;首先引入状态条件概率矢量对HMM进行不确定性改进,并推导了其表达式;其次以状态条件概率比值为基础,给出了机载设备状态等级量化分值的计算方法,并据此设计了机载设备状态健康评估流程;最后以飞机发动机温控放大器为例进行仿真验证,结果表明上述方法能够给出直观、准确的状态评估结果.     

3D imaging application in the studies of micro air vehicles

3D techniques are increasingly used in aerospace industry to improve quality and performance of aircrafts. This paper presents a 3D imaging technique for studying the aerodynamic shape and flight performance of micro air vehicles. 3D stereoscopic vision, based upon stroboscopic imaging, was utilized to obtain the 3D information of the aircraft's flexible aerodynamic surface. The aircraft models with deformable aerodynamic shape were designed and tested in a purpose-built wind tunnel experimental environment. After calculation of SIFT feature points and subdivision of triangular meshes, deformable surface of the aircraft's aerodynamic shape was represented. The aircraft's 3D visualization was used for analyzing unsteady deformation in the aerodynamic shape under external airflow disturbances. The results, together with aerodynamic forces measured in the experiment, will be useful to improve the flight performance and disturbance resistance ability of micro air vehicles.     

A QFT SUBSONIC ENVELOPE FLIGHT CONTROL SYSTEM DESIGN

An aircraft's response to control inputs varies widely throughout its full flight envelope. Furthermore, the aircraft configuration impacts control response through variations in centre of gravity and moments of inertia. Quantitative feedback theory (QFT) is a robust control system design method which provides a full-envelope flight control system design and gives the engineer direct control over compensator order and gain. A full subsonic flight envelope FCS is designed for using QFT for four representative aircraft configurations. Flying qualities are embedded in the longitudinal design by using a control variable which varies with the aircraft's energy state throughout the flight envelope. Linear simulations with realistically large control inputs are used to validate the design. © 1997 by John Wiley & Sons, Ltd. This paper was prepared under the auspices of the US Government and it is therefore not subject to copyright in the US.     

Nonlinear generalised dynamic inversion for aircraft manoeuvring control

The nonlinear control problem of aircraft trajectory tracking is tackled in the framework of multiple linear time-varying constrained control using the newly developed paradigm of generalised dynamic inversion. The time differential forms of the multiple constraints encapsulate the control objectives, and are inverted to obtain the reference trajectory-realising control law. The inversion process utilises the Moore–Penrose generalised inverse and the associated nullspace projection, and it predictably involves the problematic generalised inversion singularity. Thus, a singularity avoidance scheme based on a new type of dynamically scaled generalised inverses is introduced that guarantees both asymptotically stable tracking and singularity avoidance. The steady-state closed-loop system allows for two inherently noninterfering control actions working towards a unified goal to exploit the aircraft's control authority over the entire state space. One control action is performed by the particular part of the control law on the range space of the transposed constraint matrix, and it works to impose the prescribed aircraft constrained dynamics. The other control action is performed by the auxiliary part of the control law on the complementary orthogonal nullspace of the constraint matrix, and it provides aircraft's global inner stability using the concept of perturbed feedback linearisation. Numerical simulations of an aggressive multiaxial aircraft coordinated manoeuvre verify the efficacy of designing nonlinear flight control systems via this methodology.     

机载系统安保风险评估方法

针对影响民用飞机机载系统安全的信息安保威胁问题,通过研究ISO27005和航空工业标准,提出了一种适用于机载系统的安保风险评估方法。该方法基于威胁条件和威胁场景进行系统脆弱性分析,并结合传统的飞机安全性分析方法与安保风险评估方法,提出一套可量化的风险值计算方法。通过关系矩阵在安全性与安保等级间建立了相关性,为系统需求和架构设计提供了依据。实例验证结果表明,该方法能提供正确与可信的机载系统安保风险评估数据。     

基于MTRDL的自动飞行系统模式需求建模与验证方法[1]

在民机自动飞行过程中,自动飞行系统模式转换是影响安全的重要因素,随着现代民机机载系统的功能与复杂度的快速增长,在需求阶段对自动飞行系统模式转换的安全性分析和验证成为重要的挑战.飞行模式转换的复杂性不仅体现在自动飞行过程中必需的多重飞行模式之间的交互关系,还体现在模式转换与外部环境之间复杂的数据与控制交联关系,这些交联关系同时隐含了飞行模式转换的安全性质,这些特征提高了形式化方法的应用难度.本文工作提出一种领域特定的建模验证框架:首先,提出面向自动飞行系统模式转换的领域需求建模语言MTRDL,和基于该语言扩展于SysML上的建模方法;其次,提出基于安全需求模板的安全性质辅助规约方法;最后,通过对某机型的若干条目化需求的实例研究,证明了本文方法在自动飞行系统模式转换需求验证中的有效性.     

Judging the urgency of non-verbal auditory alarms: a case study

When designed correctly, non-verbal auditory alarms can convey different levels of urgency to the aircrew, and thereby permit the operator to establish the appropriate level of priority to address the alarmed condition. The conveyed level of urgency of five non-verbal auditory alarms presently used in the Canadian Forces CH-146 Griffon helicopter was investigated. Pilots of the CH-146 Griffon helicopter and non-pilots rated the perceived urgency of the signals using a rating scale. The pilots also ranked the urgency of the alarms in a post-experiment questionnaire to reflect their assessment of the actual situation that triggers the alarms. The results of this investigation revealed that participants' ratings of perceived urgency appear to be based on the acoustic properties of the alarms which are known to affect the listener's perceived level of urgency. Although for 28% of the pilots the mapping of perceived urgency to the urgency of their perception of the triggering situation was statistically significant for three of the five alarms, the overall data suggest that the triggering situations are not adequately conveyed by the acoustic parameters inherent in the alarms. The pilots' judgement of the triggering situation was intended as a means of evaluating the reliability of the alerting system. These data will subsequently be discussed with respect to proposed enhancements in alerting systems as it relates to addressing the problem of phase of flight. These results call for more serious consideration of incorporating situational awareness in the design and assignment of auditory alarms in aircraft.     

基于机器学习的CPS系统可靠性在线评估方法

为了对CPS系统可靠性进行有效分析与量化,提出了一种实时的CPS可靠性自动在线评估方法,该方法采用机器学习思想构建了评估框架,设计了在线排队算法,实现了对CPS可靠性的实时在线分析与评估,并能及时采取预防措施,确保系统正常无间断运行,极大地提高了系统可靠性。仿真实验结果验证了评估方法的有效性及广泛的应用前景。     

An experimental study of pilots' control characteristics for flight of an STOL aircraft in backside of drag curve at approach and landing

Abstract

In general, most vehicles can be modelled by a multi-variable system which has interactive variables. It can be clearly shown that there is an interactive response in an aircraft's velocity and altitude obtained by stick control and/or throttle control. In particular, if the flight conditions fall to backside of drag curve in the flight of an STOL aircraft at approach and landing then the ratio of drag variation to velocity change has a negative value (ΔD/Δu<0) and the system of motion presents a non-minimum phase. Therefore, the interaction between velocity and altitude response becomes so complicated that it affects to pilot's control actions and it may be difficult to control the STOL aircraft at approach and landing.

In this paper, experimental results of a pilot's ability to control the STOL aircraft are presented for a multi-variable manual control system using a fixed ground base simulator and the pilot's control ability is discussed for the flight of an STOL aircraft at backside of drag curve at approach and landing.     

民机数字化运营支持研究与方案设计

数字化运营支持是未来民机客户服务市场竞争的核心因素。未来民机型号的成功，不仅需要飞机设计于与制造的成功，更需要可持续数字化运营支持技术的成功。基于大数据分析的云端交付模式与信息安全防护体系，构建数字航空环境提供“智能服务”，搭建适合国产民机的数字化运营支持体系，保障国产民机商业成功。本文概述了数字化运营支持技术，总结出其定量化、实时化、综合化、智能化的特点。民机数字化运营支持以先进信息技术为基础，为航空公司提供数据分析、知识关联、智能辅助工具及预见性软件应用，变革运营信息的收集、传输与利用模式，从而不断提高民机安全性、可靠性、经济性与环保性。数字化运营支持是当前国际民机客户服务领域重要的技术手段与商业模式，更是未来民机客服的发展方向。     

航段油耗深度学习高质量区间预测算法

为提高给定置信水平下航段油耗区间预测结果的可靠性和稳定性,提出航段油耗深度学习高质量区间预测算法.通过对初级数据源进行按航段分类、无量纲化等预处理,提高预测结果的可靠性和算法的普适性;通过自适应相关参数、柔和化处理优化损失函数,进一步提高算法的可靠性、稳定性和普适性.训练得到的预测区间覆盖率在设定的置信水平周围,多次训...