河南省制造业信息化技术服务体系建设初探

对制造业信息化工程的发展进行了简要的回顾,详细分析了河南省制造业的现状和制造业在国民经济中所占的地位,介绍了河南省制造业信息化工程的总体目标和发展规划,探讨了技术服务体系建设的内容和方法.     

Online condition diagnosis for a two-stage gearbox machinery of an aerospace utilization system using an ensemble multi-fault features indexing approach

China manned space station is designed to operate for over ten years. Long-term and sustainable research on space science and technology will be conducted during its operation. The application payloads must meet the ‘‘long life and high reliability" mission requirement. Gearbox machinery is one of the essential devices in an aerospace utilization system, failure of which may lead to downtime loss even during some disastrous catastrophes. A fault diagnosis of gearbox has attracted attentions for its significance in preventing catastrophic accidents and guaranteeing sufficient maintenance. A novel fault diagnosis method based on the Ensemble Multi-Fault Features Indexing(EMFFI) approach is proposed for the condition monitoring of gearboxes. Different from traditional methods of signal analysis in the one-dimensional space, this study employs a supervised learning method to determine the faults of a gearbox in a two-dimensional space using the classification model established by training the features extracted automatically from diagnostic vibration signals captured. The proposed method mainly includes the following steps. First, the vibration signals are transformed into a bi-spectrum contour map utilizing bi-spectrum technology,which provides a basis for the following image-based feature extraction. Then, Speeded-Up Robustness Feature(SURF) is applied to automatically extract the image feature points of the bi-spectrum contour map using a multi-fault features indexing theory, and the feature dimension is reduced by Linear Discriminant Analysis(LDA). Finally, Random Forest(RF) is introduced to identify the fault types of the gearbox. The test results verify that the proposed method based on the multi-fault features indexing approach achieves the target of high diagnostic accuracy and can serve as a highly effective technique to discover faults in a gearbox machinery such as a two-stage one.     

Experimental investigation on dynamic response of flat blades with underplatform dampers

One test rig with three blades and two Under-Platform Dampers (UPDs) is established to better understand the dynamical behavior of blades with UPDs. A pre-loaded spring is used to simulate the centrifugal load acting on the damper, thereby achieving continuous adjustment of the pressing load. UPDs with different forms, sizes and materials are carefully designed as experimental control groups. Noncontact measurement via a laser Doppler velocimeter is employed and contact excitation which is performed by an electromagnetic exciter is adopted to directly obtain the magnitude of the excitation load by a force sensor mounted on the excitation rod. Particular attention is paid to the influence of the contact status of the contact surfaces, e.g. the pressure-sensitive paper is used to measure the effective contact area of the UPDs. The experimental variables are selected as the centrifugal force, the amplitude of the excitation force, the damper mass, the effective contact area, and the damper material. The Frequency Response Function (FRF) of the blade under different experimental parameters is obtained by slow frequency sweep under sinusoidal excitation to study the influence of each parameter on the dynamic characteristics of the blade and the mechanism analysis is carried out combined with the experimental results.     

航天中心软件的一个领域工程方法和模型

软件复用被视为提高软件开发效率和产品质量的有效途径。研究和实践表明,针对特定领域的软件复用容易取得成功。本文给出了一个基于UML2．0和体系结构视图、针对航天中心软件特点的领域工程建模方法,具体分析和设计了相应的一系列领域工程模型,它们可以成为航天中心软件复用的“核心资产”,为未来的各个应用系统开发提供有力支持。     

基于模型的系统工程在航天产品研发中的研究与实践

目前,基于模型的系统工程(MBSE)在工业界尤其在复杂装备领域,受到广泛关注。利用MBSE技术,发达国家在提升航天产品制造效率、生产力及装备的开发和部署上已经走在了世界前列。因此,深入理解MBSE概念,发展适用于我国航天工业的MBSE技术迫在眉睫。对MBSE概念及发展现状进行了深入分析,并结合初步实践经验,提出了航天MBSE技术发展方向和建议。     

空间互联网协议体系研究

随着技术的发展,航天测控的概念将发生变革,传统的测控功能将逐步演化为通信与导航。对于新体系架构中的通信部分,空间互联网是一种有效的解决方案。本文按照协议分层的原则,针对空间任务的特点和需求,对可能应用于空间通信环境的各类协议进行了系统比较和基于OPNET(优化网络工程工具)的仿真分析,在此基础上提出了一种空间互联网协议体系建议。     

机载系统合同谈判策略与方法研究

保持高效和有效有助于达成合同谈判目标。树立大团队观念、正确选择和判断谈判对手,有效进行过程把控,准确辨识谈判意图,合理分解商务报价,化冲突于无形是谈判高效、有效并最终制胜的要诀。     

飞控中心仿真系统的分布式构件化设计

简述航天飞控中心仿真系统的体系结构，简要讨论分布式体系结构和基于构件的软件设计开发，在此基础上进行飞控中心仿真系统的分布式构件化设计，给出航天飞控中心仿真系统基于ABC的CBSD过程。     

切风模式风力发电飞行器的进展与挑战

风能是当今主流的可再生能源种类之一,目前传统风力发电机只能利用近地风能,而高空风能储量巨大且较为稳定,具有很大的开发价值及潜力。对于高空风能的利用,国际上已经制定出多种方案,部分已进行了飞行试验,而国内相关研究尚处于起步阶段。围绕高空风力发电系统(AWES)的种类和发展情况进行研究,分析了切风模式AWES的飞行原理,介绍了国外代表性的切风模式AWES项目案例,指出了切风模式AWES所包含的系留缆绳、精确控制、多功能基站以及综合优化等关键问题,为国内相关领域的后续研究提供参考。     

2219铝合金搅拌摩擦焊结构ECA评定

基于含缺陷结构断裂评定的COD设计曲线与净截面屈服失效判据,对2219铝合金搅拌摩擦焊结构进行了工程临界评定(ECA)。分析了2219铝合金搅拌摩擦焊接头焊核区、热机影响区、热影响区和母材区的临界裂纹尺寸,确定了不同载荷水平下2219铝合金搅拌摩擦焊结构的表面缺陷容限,并对特定内压下2219铝合金运载火箭贮箱筒段搅拌摩擦焊纵缝进行了ECA评定,为2219铝合金搅拌摩擦焊结构的断裂控制提供了参考。研究结果表明,纵向前进边热影响区为2219铝合金搅拌摩擦焊接头断裂控制的关键区域,特定内压条件下给定的表面缺陷可以接受。