1.参加国际会议信息

·会议名称：IEEE I²MTC 2013(2013 IEEE International Instrumentation and Measurement Technology Conference)

·会议时间：6 – 9 MAY 2013

·会议地点：Minneapolis, MN, USA

·会议简介：国际仪表与测量技术会议（International Instrumentation and Measurement Technology Conference，I²MTC）是IEEE仪表与测量学会（IEEE Instrumentation and Measurement Society）主办的仪器仪表领域顶级国际学术会议，会议主题包括：仪表与测量基础、传感器与换能器、物理量测量、测量系统、测量应用、信号与图像处理、监测与故障诊断和工业应用等。其分会SPECIAL SESSION: Advanced Measurement and Data Processing for Engineering System Health Monitoring专场讨论工程系统的健康监测与故障诊断，涉及复合材料结构健康监测、磁光图像技术、齿轮箱点蚀检测等。

·会议交流工作：Presentation --Matching Demodulation Transform with Applications to Feature Extraction of Rotor Rub-impact Fault

2. 参加国际会议回校汇报安排

·汇报时间：2013年5月24日下午2点半

·汇报地点：曲江科技园机械制造系统工程国家重点实验室A228室

·汇报申请人：博士生 陈彬强、 张杰、王诗彬

3.参会论文信息

·1) 论文标题：Pseudo Non-dyadic Second Generation Wavelet Tight Frame for Machine Fault Diagnosis

·作者：陈彬强，张周锁，张杰，杨志勃，何正嘉

·摘要：This paper investigates a novel wavelet tight frame (WTF) constructing strategy for obtaining pseudo second generation bases with non-dyadic time-frequency partition grids. The proposed constructing strategy starts with a known second generation wavelet basis, and applied it in an undecimated filterbank. Via forward and inverse transformation procedure, an input signal is decomposed into a set of wavelet packets. By introducing a systematic way of wavelet packet reordering and ensemble wavelet generating method, another corresponding set of non-dyadic wavelet packets are generated. It is demonstrated that the derived pseudo non-dyadic second generation wavelet packets (PNSGW) are associated with well-defined band-pass filters, which ensures good time-frequency localizability and exact shift-invariance. The PNSGW strategy is combined with spectral kurtosis to detect incipient faults in mechanical systems. The processing results show that the proposed technique is a well complement to conventional dyadic wavelet transform in investigating transient impulse responses caused by faulty mechanical components.

·2) 论文标题：An Improved Independent Component Analysis by Reference Signals and Its Application on Source Contribution Estimation

·作者：张杰 张周锁 陈彬强 成玮 杨志勃 何正嘉

·摘要：To estimate the contribution of main vibration and noise sources of vehicles, a source contribution estimation method based on an improved independent component analysis (ICA) algorithm is proposed. A measure of the similarity between the independent components and the reference signals with given characteristics is introduced. A widely used contrast function, namely kurtosis, is enhanced by the measure to obtain an improved contrast function. By means of fixed-point iteration and deflation approach, the improved contrast function is optimized and the improved ICA algorithm is attained. The contribution is computed by the reduced energy in each extraction, the reduction of the energy corresponds to the contribution of the extracted independent components. The correspondence relationship between the independent components (ICs) and source signals can be obtained by the signal characteristics. The effectiveness of the proposed algorithm is verified by numerical simulation and experiment.

·3) 论文标题：Matching Demodulation Transform with Applications to Feature Extraction of Rotor Rub-impact Fault

·作者：王诗彬，李国英，陈雪峰，夏毅，刘忠华

·摘要：Conventional time-frequency representation (TFR) methods have played an important role in characterizing the time-frequency (TF) pattern of the nonstationary signal. In this paper, a new TFR algorithm, called matching demodulation transform (MDT), is introduced to extract the feature of highly oscillating frequency modulation for rotor rub-impact fault. When the early rub-impact fault occurs in the rotor system, the vibration signals will present frequency modulation feature because of the periodic rub-impact between the stator and the rotor. Through an iterative demodulation procedure, the highly oscillating frequency modulation feature is represented with satisfactory energy concentration in TF plane. The validity of the technique is then demonstrated on a real rotor system of a gas turbine with rub-impact fault. The analysis result of this application shows that the MDT method is powerful in the analysis of frequency modulation signals and is an effective tool for the feature extraction of rub-impact faults.

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机械工程学院

2013.5.22