【作者】 马玉；

【导师】 谷立臣；

【作者基本信息】 西安建筑科技大学 ， 机械电子工程， 2005， 硕士

【摘要】 状态监测技术是提高液压设备运行可靠性与安全性的一种手段和方法。目前,专家系统、神经网络、多媒体技术、信息融合技术等智能诊断系统已广泛的应用于液压系统的状态监测与故障诊断中。多种诊断技术的综合应用可以降低故障诊断的难度,缩短故障诊断的时间,提高工作效率为企业带来了巨大的经济效益。 本文在针对已有诊断方法不足之处的基础上,提出了基于电流信号的液压设备状态监测的新方法,并根据实际工况的监测和故障诊断的需要,研制出了电流解调装置,提取出反映液压系统运行状态的电流信号,对电流信号中蕴含的状态以及故障信息进行了深入和系统的研究,建立了液压系统功率数学模型,进而提出了监测电动机输入功率这一新的状态监测参数,实验结果表明了该方法的可行性,为产品的开发提供了科学依据。论文主要研究内容和结论概括如下: 1.通过大量理论分析和科学研究,建立了液压动力系统的动力学模型,并对机电液参数的耦合机理进行分析,论述了基于电流信号的状态识别原理。 2.分析各种液压工况下电流信号的变化规律,研制出电流解调装置,建立了各部分硬件电路的数学模型,重点分析设计解调电路和二阶有源巴特沃思低通滤波器,并对其中关键参数的设置进行计算机仿真分析,同时也实现了希尔伯特软件解调,取得了较为满意的实验结果,该装置具有越限报警的功能,为产品的开发奠定了良好的基础。 3.研究了虚拟仪器技术实现液压系统状态监测的方法,实现了基于LabVIEW软件开发平台的电动机及其液压系统功率的监测,建立了电动机—油泵的功率数学模型,分析系统空载、加载及卸载各种工况下电动机功率的变化规律,用谱分析法设计出虚拟功率监测仪,测量出各种工况下电动机的功率因数角、功率因数、瞬时功率、输入功率,实现了电动机—液压系统的功率监测。更多还原

【Abstract】 The technique of condition monitoring and measuring is a method, which is used in improving reliability and security of the running of hydraulic devices. Now, intelligence diagnoses system such as specialty system, neural network, multimedia technique, and information mixing technique have been used in the condition monitoring and failure diagnose of hydraulic system. Integrated application of the lots of diagnose technique can decrease the difficulty of diagnoses, reduce the time of diagnose, improve work efficiency bring much economic effect to enterprise.This text bring forward the method of condition monitoring and measuring of the hydraulic devices based on current, which aim at the shortage of current diagnoses method. Making current diagnose device based on working condition and failure diagnose .Pick up current signals which reflect working condition of hydraulic system , establish mathematical model of hydraulic system, bring up input power condition monitoring parameter, test result indicates the feasibility of this method. Provide science foundation for product development. The main content and conclusion of this text are as follows:1. Establish dynamic model of hydraulic system through theoretical analysis and scientific study, analysis cupping parameter, discuss the principle of current signal condition identification.2. Analysis the changing rules of current signal at all kinds of working condition, making current demodulation equipment. Establish mathematical model of hardwired connection, analyze demodulated current and second-order active Butterworth low pass filter, imitating analysis the important parameter, finish the software demodulated of Hilbert transform, the test result is good. The equipment is provide with the function of giving a alarm out of limit, laid the groundwork for the future product development.3. Analysis condition monitoring method of hydraulic system using virtual device,realize the power monitoring of hydraulic system and motor based on software development of LabVIEW, establish power mathematical model of motor-oil pump, analysis the power changing rules of motor on the working condition of no loading, loading, unloading. Design the power monitoring instrument using the methods of analysis of spectrum, measuring the power factor, instantaneous power and so on, realize the power monitoring of motor- hydraulic system.更多还原