【作者】 关晋凯；

【导师】 赵克定； 袁立鹏；

【作者基本信息】 哈尔滨工业大学 ， 机械电子工程， 2009， 硕士

【摘要】 振动台是实验室内模拟真实的振动环境的重要试验设备,其中电液伺服角振动台作为一种独特的环境模拟设备在导弹、火箭、卫星等国防领域有着重要的作用。为了更真实的模拟实际的振动环境,只对电液伺服角振动台进行正弦振动控制已经无法满足要求,随机振动控制的研究在角振动控制技术领域显得越来越重要。随机振动控制要求振动试验系统具有高频响性能,电液伺服角振动台的液压动力机构是阀控马达系统,而电液伺服阀控马达系统的固有频率较低,因此研究扩展阀控马达系统频宽的伺服控制方法对于随机角振动控制非常关键。本文针对单轴电液角振动台系统建立完整的阀控马达系统的数学模型,研究有效提高系统频宽的三状态控制策略,根据极点配置原理设计三状态控制器。并通过仿真分析验证三状态控制策略可以有效拓展系统频宽。在随机振动控制中,仅依靠伺服控制提高系统频宽不能满足随机振动复现控制精度,主要是由于试验系统中存在的非线性和系统频宽拓展的局限性所致。要高精度复现随机振动形式,必须进行随机振动的复现迭代控制。本文重点分析了随机振动的波形复现迭代控制算法和功率谱复现迭代控制算法。在复现迭代算法中频响函数估计的精确程度对迭代结果有很大的影响,本文分析了传统的频响函数估计方法及其存在的问题,提出了一种基于自适应滤波原理的频响函数辨识方法,分析了自适应滤波原理,采用了改进的变步长自适应滤波算法-LMS算法。该频响函数辨识方法具有自适应滤波的特点,是一种能够随系统频率特性变化而实时调整的频响函数估计方法,并且不需要关注信号噪声的统计特性。本文分析了迭代过程中的响应谱估计、驱动谱修正和时域信号生成等,并对驱动谱修正做出了变系数的改进。最后通过仿真验证振动迭代控制理论的分析结论。通过单轴电液角振动试验来验证本文的理论研究内容,单轴角振动试验主要包括了三状态控制器调试试验、频响函数辨识试验、波形复现控制试验和功率谱复现控制试验。更多还原

【Abstract】 Vibration table is a kind of standard experiment equipment which is used to replicate the real vibrate environment. Among them, electro- hydraulic servo vibration table is a special kind of vibration environment simulated equipment which is widely used in national defense industry, such as missiles, rockets and satellites. To replicate real vibrate environment more accurately, not only is it necessary to study sine vibration control technology , but also is it a key for vibration control technology to study random vibration control’s application in industrial fields.Random vibration control system demands that the vibration system has high frequency response. But power mechanism of electro-hydraulic servo angular vibration table is motor controlled by the valves, the frequency response of which is lower. The study of the servo method that can heighten the system frequency response is a key technology to random angular vibration control. The mathematical model of motor controlled by the valves is set up. There variable control is a effective method to improve the system frequency response. In the paper, the author analyses the principle of there variable controller. According the principle, the author design the there variable controller for electro-hydraulic servo angular vibration table. The applicability of the new control method is indicated by the simulation.In the random vibration control, random vibration iteration precision is lower than expected only by servo control technology. The main reasons consist of the system’s nonlinear and the restraint of the system frequency response. It is necessary to present random vibration replication control algorithm, to improve the control precision. The paper analyses mainly waveform replication iteration algorithm and PSD replication iteration algorithm. Frequency response function estimated is the foundation of random vibration control and its results estimated is directly related to vibration control accuracy. The paper presents the traditional frequency response function estimating method and analysis defects of this method. The paper introduces the principle of adaptive filtering, adaptive filter structure and the realization of the type of adaptive algorithm, then presents a new frequency response function estimating method based on the principle of adaptive algorithm. The method has the features of adaptive filters. The frequency response function estimated can be adjusted according to the changes of vibration table system, without the effect of the changes of noise’s statistical properties. The paper also analysis other key parts of random vibration replication iteration algorithm, including estimating of response spectrum, correction of driver spectrum iteration, generation of time-domain driver signal. The paper makes improvements to correction of driver spectrum iteration, with different correct modulus in different frequency band. The vibration replication iteration control theory is indicated by the simulation in Matlab.The paper analysis electro-hydraulic servo angular vibration test’s results, and indicates the above conclusion. Angle vibration test consists of frequency response function estimating test, waveform replication iteration vibration test and PSD replication iteration vibration test.更多还原