基于不平衡响应的磁悬浮轴承刚度阻尼的辨识

发布时间：2018-01-19 08:45

本文关键词： 不平衡响应磁悬浮轴承刚度阻尼 FIR 转子有限元建模　出处：《南京航空航天大学》2012年硕士论文　论文类型：学位论文

【摘要】：磁悬浮轴承是利用电磁力作用使转子悬浮于空间，实现无摩擦的一种新型高性能轴承。磁悬浮轴承的动力特性对整个系统的动态特性影响很大，而研究磁悬浮轴承的动力特性的难点在于磁悬浮轴承支承刚度和阻尼的确定。现阶段国内外还没有一套完整的理论和方法来确定磁悬浮轴承的刚度和阻尼。因此，本文研究一种基于不平衡响应的磁悬浮轴承的刚度和阻尼的辨识方法，并用仿真和试验验证该方法的可行性。首先在MSC.Patran中完成磁悬浮转子有限元模型的建立，对转子建模过程中提高建模准确性以及转子不平衡响应分析中不平衡质量施加的问题做了详细描述。详细说明了辨识磁悬浮轴承刚度阻尼的基本原理，，运用Matlab编写了辨识程序，用几种不同刚度和阻尼支承情况的算例进行辨识仿真来验证基于不平衡响应方法的正确性。为验证基于不平衡响应辨识磁悬浮轴承刚度阻尼的方法的可行性，运用MSC.Nastran和Matlab对实验室现有的磁悬浮轴承的刚度阻尼进行仿真辨识。仿真结果表明该方法可以正确辨识轴承的刚度和阻尼。将基于不平衡响应的磁悬浮轴承的刚度和阻尼的辨识方法用到一个五自由度的磁悬浮轴承试验台上进行辨识试验。针对试验中采集的不平衡响应信号的是多个标准的正弦信号和高频信号的迭加的情况，本文设计了低通FIR滤波器进行滤波来提取目标信号，经滤波仿真表明滤波器符合要求。试验中用NI数据采集卡采集试验信号，在Matlab中完成滤波、提取不平衡响应信号的幅值相位进而辨识磁悬浮轴承的刚度和阻尼。为验证辨识结果的正确性，将试验辨识的结果代入有限元软件，赋予转子有限元模型试验辨识的刚度和阻尼做不平衡响应计算，研究计算结果与试验结果，表明本文采用的辨识方法在一定程度上可以辨识刚性转子下的磁悬浮轴承刚度和阻尼。
[Abstract]:Magnetic bearing is a new kind of high performance bearing which uses electromagnetic force to make the rotor suspended in space and realizes no friction. The dynamic characteristics of magnetic suspension bearing have a great influence on the dynamic characteristics of the whole system. The difficulty of studying the dynamic characteristics of maglev bearing is the determination of bearing stiffness and damping. At present, there is no complete theory and method to determine the stiffness and damping of maglev bearing. . In this paper, an identification method of stiffness and damping of magnetic bearing based on unbalanced response is studied, and the feasibility of this method is verified by simulation and experiment. Firstly, the finite element model of maglev rotor is established in MSC.Patran. In this paper, the problems of improving the accuracy of rotor modeling and the unbalance mass applied in rotor unbalance response analysis are described in detail, and the basic principle of identifying stiffness and damping of magnetic suspension bearing is explained in detail. The identification program is written with Matlab. Several examples of different stiffness and damping support are used to verify the correctness of the method based on unbalanced response. In order to verify the feasibility of the method based on unbalanced response to identify the stiffness and damping of maglev bearing. MSC.Nastran and Matlab are used to identify the stiffness and damping of the existing maglev bearing in laboratory. The simulation results show that the method can correctly identify the stiffness and damping of the bearing. The identification method of stiffness and damping of maglev bearing based on unbalanced response was applied to a five-degree-of-freedom maglev bearing test rig. The superposition of standard sinusoidal and high-frequency signals. In this paper, a low-pass FIR filter is designed to filter the target signal, and the filter simulation shows that the filter meets the requirements. NI data acquisition card is used to collect the test signal in the experiment. Filtering is completed in Matlab to extract the amplitude and phase of the unbalanced response signal and then to identify the stiffness and damping of the maglev bearing to verify the correctness of the identification results. The results of test identification are replaced by finite element software, and the stiffness and damping of finite element model identification of rotor are given to calculate the unbalanced response, and the results of calculation and test are studied. It is shown that the identification method can identify the stiffness and damping of magnetic bearing under rigid rotor to some extent.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH133.3

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