机械故障特征具有周期性、稀疏性以及被噪声污染严重特点,而大部分特征抽取方法(如局部线性嵌入(locally linear embedding,LLE)、局部切空间排列(local tangent space alignment,LTSA))性能往往受到噪声影响.因此,抑制振动信号噪声、...机械故障特征具有周期性、稀疏性以及被噪声污染严重特点,而大部分特征抽取方法(如局部线性嵌入(locally linear embedding,LLE)、局部切空间排列(local tangent space alignment,LTSA))性能往往受到噪声影响.因此,抑制振动信号噪声、抽取有效故障特征成为机械故障检测的关键.本文提出融合奇异值分解与周期重叠簇稀疏(reweighted singular value decomposition integrating with periodic overlapping group sparsity,RSVD-POGS)的机械故障稀疏特征抽取方法.该方法首先利用RSVD把多成分振动信号分解为奇异成分集合,并使用周期调制强度(periodic modulation intensity,PMI)准则选择有效奇异成分,然后使用POGS从奇异成分提取稀疏周期冲击特征,并由选择的奇异成分重构原始信号,增强周期稀疏故障信号特征.最后,使用低SNR仿真周期冲击信号对RSVD-POGS算法与POGS方法进行对比,并将RSVD-POGS方法应用于实验台轴承正常和故障信号的特征提取中.实验结果表明,该算法可以有效地提取稀疏微弱故障特征,具有较大的优越性.展开更多
Rice stripe virus disease （RSVD） and rice black-streaked dwarf virus disease （RBSDVD） are two epidemic diseases in Yancheng City, Jiangsu Province in the last decade. The authors investigated the disaster regulari...Rice stripe virus disease （RSVD） and rice black-streaked dwarf virus disease （RBSDVD） are two epidemic diseases in Yancheng City, Jiangsu Province in the last decade. The authors investigated the disaster regularity, prevention and control technology of RSVD and RBSDVD systematically. The occurrence and virus transmission of SBPH and disaster regularity of virus diseases were studied; the resistance of some rice varieties was cleared; the effects of physical and agricultural measures such as insect net blocking, appropriate late sowing and plowing on controlling occurrence and virus transmission of SBPH were figured out; a hatch of chemical agents were screened, providing efficient and harmless pesticides for effective control against SBPH and prevention against virus diseases. A set of disaster control and mitigation technologies was proposed in this paper, which was practical, sustainable, and easy to operate for the local planting patterns.展开更多
文摘机械故障特征具有周期性、稀疏性以及被噪声污染严重特点,而大部分特征抽取方法(如局部线性嵌入(locally linear embedding,LLE)、局部切空间排列(local tangent space alignment,LTSA))性能往往受到噪声影响.因此,抑制振动信号噪声、抽取有效故障特征成为机械故障检测的关键.本文提出融合奇异值分解与周期重叠簇稀疏(reweighted singular value decomposition integrating with periodic overlapping group sparsity,RSVD-POGS)的机械故障稀疏特征抽取方法.该方法首先利用RSVD把多成分振动信号分解为奇异成分集合,并使用周期调制强度(periodic modulation intensity,PMI)准则选择有效奇异成分,然后使用POGS从奇异成分提取稀疏周期冲击特征,并由选择的奇异成分重构原始信号,增强周期稀疏故障信号特征.最后,使用低SNR仿真周期冲击信号对RSVD-POGS算法与POGS方法进行对比,并将RSVD-POGS方法应用于实验台轴承正常和故障信号的特征提取中.实验结果表明,该算法可以有效地提取稀疏微弱故障特征,具有较大的优越性.
基金Supported by Agricultural "Three-item" Project of Jiangsu Province "Promotion of Comprehensive Prevention and Control Technology of Major Pests and Diseases such as Rice Stripe Virus Disease" [SX(2005)029] & Agricultural "Three-item" Project of Jiangsu Province "Prevention and Control Technology of Rice Black-streaked Dwarf Virus Disease"[SX(2008)018] & Agricultural "Three-item" Project of Jiangsu Province "Integration and Popularization of Prevention and Control Technology of Rice Black-streaked Dwarf Virus Disease"[SX(2009)49]
文摘Rice stripe virus disease （RSVD） and rice black-streaked dwarf virus disease （RBSDVD） are two epidemic diseases in Yancheng City, Jiangsu Province in the last decade. The authors investigated the disaster regularity, prevention and control technology of RSVD and RBSDVD systematically. The occurrence and virus transmission of SBPH and disaster regularity of virus diseases were studied; the resistance of some rice varieties was cleared; the effects of physical and agricultural measures such as insect net blocking, appropriate late sowing and plowing on controlling occurrence and virus transmission of SBPH were figured out; a hatch of chemical agents were screened, providing efficient and harmless pesticides for effective control against SBPH and prevention against virus diseases. A set of disaster control and mitigation technologies was proposed in this paper, which was practical, sustainable, and easy to operate for the local planting patterns.
