基于NIOSII处理器的IEEE-1394b双向数据传输系统

基于FPGA内嵌的NIOSII处理器.设计了一个1394b双向数据传输系统.介绍了该系统的硬件结构.描述了其软件工作流程,主要包括异步传输和等时传榆的具体实现过程.测试结果表明,该系统的传输速率较高、可靠性和实时性较好,并具有一定的应用价值.     

基于MODWPT的包络阶次谱在滚动轴承故障诊断中的应用

为了有效提取滚动轴承的故障特征,提出了基于MODWPT的包络阶次谱故障诊断方法.采用MODWPT将多分量的滚动轴承振动信号分解为若干个分量,对各个分量信号进行包络分析并对包络信号进行角域重采样;最后对重采样后的信号进行频谱分析,得到包络阶次谱,从而判断滚动轴承的工作状态和故障类型.采用该方法分别对仿真信号和实验信号进行了分析,结果表明了该方法的有效性.     

A Roller Bearing Fault Diagnosis Method Based on Improved LMD and SVM

Aiming at the non-stationary features of the roller bearing fault vibration signal,a roller bearing fault diagnosis method based on improved Local Mean Decomposition(LMD)and Support Vector Machine(SVM)is proposed.In this paper,firstly,the wavelet analysis is introduced to the signal decomposition and reconstruction;secondly,the LMD method is used to decompose the reconstruction signal obtained by the wavelet analysis into a number of Product Functions(PFs)that include main fault characteristics,thus,the initial feature vector matrixes could be formed automatically;Thirdly,by applying the Singular Value Decomposition(SVD)techniques to the initial feature vector matrixes,the singular values of the matrixes can be obtained,which can be used as the fault feature vectors of the roller bearing and serve as the input vectors of the SVM classifier;Finally,the recognition results can be obtained from the SVM output.The results of analysis show that the proposed method can be applied to roller bearing fault diagnosis effectively.