Adaptive sensitive frequency band selection for VMD to identify defective components of an axial pis

来源 :中国航空学报(英文版) | 被引量 : 0次 | 上传用户:beckham621
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
The underlying study investigates single valued neutrosophic entropy based adaptive sensitive frequency band selection for variational mode decomposition(VMD)for the purpose of identifying defective components in an axial pump.The proposed methodology is applied in the fol-lowing steps.First,VMD is applied for decomposing vibration signals into various frequency bands,called as modes.After computing energy of each VMD,the lower(minimum)and upper(maximum)bounds from these energy readings are extracted for defect conditions,such as outer race,inner race,worn piston,faulty cylinder and valve plate,and blocked hole of the piston.There-after,energy interval ranges are obtained and further converted into the form of single valued neu-trosophic sets(SVNSs).Then,the proposed neutrosophic entropy measure is deployed for quantifying the non-linear connection between each bearing defect conditions and various fre-quency bands.The mode having maximum neutrosophic entropy value is designated to the“most sensitive”frequency band.Thereafter,envelope demodulation is applied to the most sensitive selected frequency band for finding defective components.The proposed neutrosophic entropy and VMD based methodology is effective in providing a better insight for selecting suitable fre-quency band for carrying out envelope demodulation in comparison to existing methods.
其他文献
充填土料中粉粒含量对充填管袋的脱水性能影响较大,进而影响到管袋筑坝的施工周期.考虑袋体缝制方式对脱水特性的影响,在研究充填料含粉量对纵向吊袋脱水影响的基础上进行了横向吊袋脱水试验,研究5种不同级配下横向吊袋脱水量随时间的变化规律,并分析充填料含粉量与脱水速率之间的关系以及与纵向吊袋脱水试验结果进行对比分析.研究结果表明:横向吊袋的脱水过程分为稳定阶段和不稳定阶段,其中,稳定阶段为脱水过程的主导阶段,且该阶段内的脱水速率与脱水时间呈线性关系,在不稳定阶段中,脱水速率随时间略有波动,待吊袋内形成稳定的反滤结构
在中国北方寒冷地区,温度低、雨雪量大等特殊环境,导致隧道拱顶出现渗水结冰的现象,在一定程度上破坏结构也影响行车安全.因此,如何针对这类冻害做出防治措施成为行业内重点关心的话题.人工、风力扫冰器以及融冰装置除冰技术等各类方式在很多工程维修养护过程中得到应用,但是基于寒区背景下,除冰技术在一些方案实施阶段中存在差异性.为此,文章首先分析比较3种除冰技术的特点,并结合实地案例,根据哈尔滨黎明大道公路隧道渗水结冰现象,对融冰装置的除冰效果进行实验分析,最终的分析结果和实验结论可为今后寒区隧道工程建设提供借鉴.
The initial corrosion behavior and mechanism of 7B04 aluminum alloy under acid immersion and salt spray environments(pH=3.5)are studied by Scanning Electron Microscope(SEM),optical microscope,Fourier Transform Infrared Spectroscopy(FT-IR),X-Ray Diffractio
Due to the strong background noise and the acquisition system noise,the useful characteristics are often difficult to be detected.To solve this problem,sparse coding captures a con-cise representation of the high-level features in the signal using the und
以水滑石(LDH)为载体,山梨酸钾(SBA)和SBA-十二烷基硫酸钠(SDS)为客体插层分子,通过焙烧复原法制备SBA-LDH和SBA-SDS-LDH两种插层复合材料.采用傅里叶变换红外光谱(FTIR)、X射线粉末衍射(XRD)、扫描电镜(SEM)和热重-差热分析(TG-DSC)对插层材料的结构和热稳定性进行表征和分析,并考察其在不同pH缓冲溶液体系中的缓释性能.结果表明,SBA和SBA-SDS能够插入到LDH板层间,客体阴离子以长轴垂直的方式排列.两种材料在pH为4.4和3.4的缓冲体系中均表现出良好的
Hemispherical Resonator Gyroscope(HRG)is a classical high precision Coriolis Vibration Gyroscope(CVG),which performs attitude estimation of carrier by detecting the precession of standing wave of resonator,thus,the drift of standing wave of resonator has
As one of the promising configurations of the next generation of commercial aircraft,research on departure characteristics of the Blended-Wing-Body(BWB)is of great signification to safe flight limits.A three-degree-of-freedom(3-DOF)virtual flight test in
通过阅读相关文献,提取出8个影响建筑业转型升级的因素,用灰色关联理论计算出各因素与建筑业转型升级的关联程度,然后用AHP法计算出各因素的权重.根据算例分析的结果可以看出,各因素对建筑业的转型升级都有一定的影响,其中,影响较大的因素分别为政府出台的相关政策、技术创新能力、市场管理因素,并在此基础上提出一些针对性的对策建议.
由于燃料电池混合动力皮卡车能量转化效率高、无污染且续航里程理想,其逐渐成为未来皮卡市场的发展趋势.基于Cruise-Simulink联合仿真平台对某款皮卡车进行整车建模,采用一种燃料电池与蓄电池混合的动力系统,通过仿真曲线进行分析,结果表明:本款皮卡车在最高车速、续航里程、爬坡度以及耗能经济性方面均符合设计要求且优于原型燃油车.