【作者】 郭瑜；

【导师】 秦树人；

【作者基本信息】 重庆大学 ， 机械电子工程， 2003， 博士

【摘要】 旋转机械在机械装备中占有举足轻重的地位，它们大多为生产企业中的关键设备，因此，保证旋转机械的安全可靠运行对企业和国民经济有重要的意义。旋转机械特征分析是旋转机械故障诊断和状态监测的重要组成部分，其中的振动测试方法又是特征分析的主要手段，而特征信息提取技术的高低主要取决于相应测试仪器的分析功能。目前的测试仪器对平稳振动信号有比较成熟和完善的测试和分析手段，但在对以升、降速过程为代表的旋转机械非平稳振动信号的特征提取方面还缺乏完善而有效的分析功能，这也意味着现有测试仪器在旋转机械非平稳振动信号的分析上还不能很好地适应旋转机械的高速化、精密化和自动化的发展需要。因此迫切需要对现有技术的进行补充和完善，并增加新的分析功能。本文在对旋转机械典型故障特征、传统特征分析方法和非平稳信号的时频分析技术进行了详细介绍的基础上，将时频分析技术引入旋转机械特征分析领域；同时，对旋转机械特征分析的主要手段——阶比分析技术进行了深入研究，利用信号的瞬时频率与旋转机械转速的对应关系提出了实现阶比分析的崭新途径，并在工程实践中证明了这一途径的正确性。在课题研究中提出了基于瞬时频率估计的旋转机械阶比跟踪方法，该方法用时频分析技术中的峰值搜索方法直接从原始振动信号中获得旋转机械多分量振动信号中与转速相对应的瞬时频率估计，并通过曲线拟合的方法获得瞬时转速曲线，最后实现了阶比分析中的阶比跟踪采样，成功解决了原来阶比跟踪方法中存在的需要转速计、鉴相装置等专门辅助硬件设备和由此产生的复杂安装要求等问题，使阶比分析实现途径得以简化，并降低了阶比分析的使用成本。通过对阶比跟踪滤波方法进行了深入研究，针对原有硬件方法中存在的需要转速计、跟踪滤波器等专门硬件辅助设备和计算阶比跟踪滤波中使用分块数字滤波会产生的边沿效应问题，提出了基瞬时频率估计和零相位数字滤波的阶比跟踪滤波方法。该方法是对现有方法的发展和补充。研究并实现了基于时频滤波的阶比分量提取。该技术采用了时频分析中的Gabor变换，可有效地对旋转机械振动信号中的阶比分量信号进行重构提取，使对选定的阶比分量进行单独分析提供了可能。基于以上研究成果，在实现了无需转速计的旋转机械阶比分析，包括：阶比谱分析、阶比谱阵、跟踪阶比谱和阶比分量提取等。这些分析功能的简化实现为旋转机械特征分析仪器的成功开发奠定了基础。开发出虚拟式旋转机械特征分析仪。该特征分析仪具有时频分析功能和基于<WP=5>研究成果的阶比分析功能，可实现对旋转机械非平稳信号特征信息的有效提取和分析，弥补了传统仪器在非平稳信号分析方面的不足，显示了虚拟仪器这一全新仪器设计理念的强大优势。研究中用开发的虚拟式旋转机械特征分析仪对不同的测试对象进行了实测分析，试验结果表明所研究和提出的方法的有效性，同时也展示了所开发的虚拟仪器具有强大的非平稳信号分析功能。本项目系国家自然科学基金重点资助项目“面向机械测试的控件化虚拟仪器系统的研究”（批准号: 50135050）之子项目。更多还原

【Abstract】 Rotating machinery takes up the major part in all machinery equipments and plays an important role in industry enterprises. It is very important to ensure the running safety of rotating machinery for both enterprises and our society. Characteristics analysis plays an important role in faults find and diagnosis of rotating machinery. Vibration measurement and test is a popular method in all characteristics analysis methods. The level for getting information depends on the analysis functions associated with the measurement instruments. Up to now, most measurement instruments often used are very good to analysis stationary vibration of rotating machinery, but is lacking in non-stationary vibration characteristics analysis to some extend, for example, the vibration caused by rotating machinery during run-up or coast down. This means the non-stationary vibration analysis functions current used in measurement instruments are not satisfied the requirement by the advanced development of rotating machinery which with high speed and high precision. So, it is urgent to continue perfect the techniques current used and add new analysis functions.In this dissertation, time-frequency analysis methods were introduced in the characteristics analysis of rotating machinery. While a good study to classic faults characteristics of rotating machinery, traditional methods for characteristics analysis and the time-frequency analysis for non-stationary signals, an important research were carried on order analysis, a very powerful tool for characteristics analysis of rotating machinery. Some new methods to perform order analysis were proposed and successful done based on the relationship between the instantaneous frequency of vibration signal and the rotating speed of machinery.Order tracking of rotating machinery based on instantaneous frequency estimation was proposed in our research. In this method, the speed corresponding instantaneous frequency estimation was attained from multi-components vibration signals by peak searching on time-frequency plane, curve fitting was employed to obtain the instantaneous frequency law, and order tracking sampling was done for order analysis. By this method, some special hardware, such as speed counter, keyphasor device, etc. are avoid, and the corresponding installation limited required by traditional order tracking methods is not exist too. It makes the order analysis simplified and can be performed at a low cost. <WP=7>By deep study and advanced research on traditional order tracking filtering method, a new order tracking filtering method based on instantaneous frequency estimation and zero-phase distortion digital filtering was proposed. It overcomes the problems of hardware requirement for speed counting and analog tracking filter to do tracking filtering in past time. It is an effective adding to traditional order tracking filtering methods.Order component extraction based on time-frequency filtering was also researched. Gabor transform, a popular time-frequency analysis method, is employed to do the order component extraction by signal synthesis. So, the order component selected can by treat alone by further analysis. The tacholess order analysis, such as order spectrum, order matrix and tracking order spectrum, order component extraction etc., was programmed based on these mentioned above. All of these functions provided a good foundation for the developing of virtual characteristics analyzer of rotating machinery.A virtual instrument, rotating machinery characteristics analyzer, was programmed with some powerful time-frequency analysis functions and all order analysis functions introduced above. So, it is enabled the abilities to analysis non-stationary vibration of rotating machinery and eliminate the weak points of current used measurement and test instruments. The advantage of instruments developing by the new virtual instruments developing concept is also well showed by it.Many actual tests for different test objects were done with the virtual characteristics analyzer更多还原