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261.
工作流管理技术是在计算机环境支持下实现经营过程集成与经营过程自动化,是由工作流管理系统执行的业务模型。 相似文献
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以信息技术改造传统产业,促进航空企业的跨越发展——成飞企业信息化建设的回顾和展望 总被引:2,自引:2,他引:0
简要介绍了成飞企业信息化建设的发展历程 ,重点介绍了成飞CIMS工程实施概况、特点和所产生的效益 ,并对成飞企业信息化建设前景做了展望 相似文献
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无人机的空域集成,即无人机进入非隔离空域飞行与有人机共享空域,是未来发展的必然趋势,这也给空中交通管理带来了新的挑战.参照美国的空域集成计划,需要建立在空域详细分类的基础上,根据无人机的综合能力逐步实现无人机从单一空域到多空域,从隔离空域到非隔离空域的动态运行.而无人机的综合能力分类可以从体系划分和安全能力两个角度出发,综合衡量;其中,无人机体系基于自主能力和监管方式两个关键因素来划分.基于这种方法,分析可以初步确定一类无人机可以飞行的空域类型,以及跨越不同空域的方式,从而实现无人机空域集成. 相似文献
268.
Integration of GPS and low cost INS for pedestrian navigation aided by building layout 总被引:1,自引:1,他引:0
In outdoor environments, GPS is often used for pedestrian navigation by utilizing its signals for position computation, but in indoor or semi-obstructed environments, GPS signals are often unavailable. Therefore, pedestrian navigation for these environments should be realized by the integration of GPS and inertial navigation system (INS). However, the lowcost INS could induce errors that may result in a large position drift. The problem can be minimized by mounting the sensors on the pedestrian's foot, using zero velocity update (ZUPT) method with the standard navigation algorithm to restrict the error growth. However, heading drift still remains despite using ZUPT measurements since the heading error is unobservable. Also, tbot mounted INS suffers from the initialization ambiguity of position and heading from GPS. In this paper, a novel algorithm is developed to mitigate the heading drift problem when using ZUPT. The method uses building lay- out to aid the heading measurement in Kalman filter, and it could also be combined for the initial- ization. The algorithm has been investigated with real field trials using the low cost Microstrain 3DM-GX3-25 inertial sensor, a Leica GS10 GPS receiver and a uBlox EVK-6T GPS receiver. It could be concluded that the proposed method offers a significant improvement in position accuracy for the long period, allowing pedestrian navigation for nearly40 min with mean position error less than 2.8 m. This method also has a considerable effect on the accuracy of the initialization. 相似文献
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Operations in assembling and joining large size aircraft components are changed to novel digital and flexible ways by digital measurement assisted alignment.Positions and orientations(P&O)of aligned components are critical characters which assure geometrical positions and relationships of those components.Therefore,evaluating the P&O of a component is considered necessary and critical for ensuring accuracy in aircraft assembly.Uncertainty of position and orientation(U-P&O),as a part of the evaluating result of P&O,needs to be given for ensuring the integrity and credibility of the result;furthermore,U-P&O is necessary for error tracing and quality evaluating of measurement assisted aircraft assembly.However,current research mainly focuses on the process integration of measurement with assembly,and usually ignores the uncertainty of measured result and its influence on quality evaluation.This paper focuses on the expression,analysis,and application of U-P&O in measurement assisted alignment.The geometrical and algebraical connotations of U-P&O are presented.Then,an analytical algorithm for evaluating the multi-dimensional U-P&O is given,and the effect factors and characteristics of U-P&O are discussed.Finally,U-P&O is used to evaluate alignment in aircraft assembly for quality evaluating and improving.Cases are introduced with the methodology. 相似文献
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微机电系统(MEMS)被认为是21世纪的一项“使能”技术,对航空工业的技术革新将产生重大影响.本文介绍了MEMS在航空领域的典型应用,包括微惯性测量系统、微型飞行器、微流控和灵巧蒙皮、集成光电器件、发动机智能控制等,并探讨了未来MEMS的发展趋势 相似文献