Fault Diagnosis Method Based on Fractal Theory and Its Application in Wind Power Systems

The non-linear dynamic theory brought a new method for recognizing and predicting complex non-linear dynamic behaviors. The non-linear behavior of vibration signals can be described by using fractal dimension quantitatively. In this paper, a fractal dimension calculation method for discrete signals in the fractal theory was applied to extract the fractal dimension feature vectors and classified various fault types. Based on the wavelet packet transform, the energy feature vectors were extracted after the vibration signal was decomposed and reconstructed. Then, a wavelet neural network was used to recognize the mechanical faults. Finally, the fault diagnosis for a wind power system was taken as an example to show the method’s feasibility.     

自动机机箱振动分析与诊断研究

自动机射击动作时因激振力的作用会产生一定方向和频率的冲击振动,构件的裂纹或松动等故障会影响到其响应成分的频率能量特性;针对自动机实射动作冲击响应振动信号,利用小波分析快速进行信噪分离,频域范围内采用功率谱分析结合小波包分解对各频段能量谱分析。根据振动信号时域峰值和时刻,频域能量的变化和分布,给出故障诊断层使用的状态特征向量,并用比例梯度动量共轭算法训练的神经网络模型进行自动机状态定位与故障识别。     

一种动态自动称量技术

针对某些发射药颗粒较大,不能满足快速、精确称量的问题,设计一种动态自动称药控制系统。该系统主要采用皮带送药技术、气动震盘送药技术和在一定范围设置称药量值进行称量技术,通过粗加药与精加药比重的控制方法和设置控制提前量的控制策略,实现了大颗粒发射药的动态自动称量,并已在某发射药自动称量机项目中成功应用。实践结果证明:该技术降低了工人的劳动强度,提高了生产效率。     

New quaternary additive for processing fully ceramic microencapsulated fuels without applied pressure

To apply SiC ceramics as a matrix for fully ceramic microencapsulated (FCM) fuels, the equivalent boron content (EBC) factors of elements in the sintering additives should be considered as an important criterion. A previously developed quaternary additive composition based on AlN–Y₂O₃–Sc₂O₃–MgO contained Sc, which has a relatively high EBC factor (8.56 × 10^?3). This study proposes a novel quaternary additive composition (AlN–Y₂O₃–CeO₂–MgO), in which Sc is replaced by Ce (EBC factor = 6.36 × 10^-5). The new additive composition achieved successful densification of the SiC matrix at 1850 °C without applied pressure. FCM pellets containing 36 vol% tristructural isotropic (TRISO) particles were successfully sintered at 1850 °C using the above matrix without applied pressure. The thermal conductivities of the FCM pellets prepared via pressureless sintering with 36 vol% TRISO particles were 43.9 W·m^-1·K^-1 and 25.8 W·m^-1·K^-1 at 25 °C and 500 °C, respectively.     

提高FTF12E3+AD型加弹机自动落筒成功率

介绍FTF12E3+AD型加弹机自动落筒系统,分析其优势和目前存在的设计缺陷,分别对自动络筒系统的皮辊轴、废丝管歧管等部件的设计形式、材质提出新的改进思路,并进行了实际的改造,总结了改造效果。     

一种自动收卷条状热熔胶粘剂新设备

提供1种自动收卷热熔胶粘剂的新设备,适用于所生产的圆条状热熔胶粘剂在检测合格后,即刻收卷到特制的线盘上,多层整齐排列,在达到设定的长度后停止收卷,更换新盘。所研制的设备已经用于实际生产,效果良好。     

紧急切断阀过流性能检测装置的研制

文章介绍了紧急切断阀过流性能检测装置的总体设计方案,解决了紧急切断阀的自动夹紧的关键问题和人工读取试验结果的误差问题。通过本装置,能够实现紧急切断阀密封性能、耐压性能和过流性能试验。电脑检测系统自动记录相关试验数据,自动判断其性能是否符合有关标准要求并打印出报告,有效地提高紧急切断阀检验结果的准确性。     

基于振冲法的坝基液化处理设计及施工监控

本文通过对振冲法处理液化土层的多种复合功效的系统分析,采用功效当量标贯法计算抗液化临界标贯击数,从而得出合理的抗液化临界桩距.基于抗液化振冲处理的能量准则,开发研制了振冲法施工过程的自动监控系统,有效地保证了施工质量.     

外部代码在自动测试系统软件开发中的应用

在介绍虚拟仪器及其开发平台LahVIEW,指出通过调用外部代码接口可以实现与C语言的混合编程。结合一个实例,证明了合理的运用外部代码可以节约系统硬件成本,降低图形化编程的繁杂度,提高程序的执行效率,增强LahVIEW的整体功能。     

USB-GPIB控制器VISA函数库的开发及在Visual C++中的应用

将USB所具有的独特优点引入到以GPIB为标准的自动测试系统中,设计并开发了具有USB总线的GPIB接口控制器和性能较为完善的VISA函数库,介绍了所设计的GPIB控制器VISA标准函数的格式与功能。采用该USB-GPIB控制器和VISA函数库可以更方便地组建GPIB自动测试系统和进行灵活地系统测控软件的开发,对于提高GPIB自动测试系统的整体性能具有很大作用。本文最后给出了Visual C＋＋中VISA的应用实例。