基于静电传感器的旋转机械转速测量方法研究

发布时间：2018-01-04 05:30

本文关键词：基于静电传感器的旋转机械转速测量方法研究　出处：《华北电力大学》2015年博士论文　论文类型：学位论文

【摘要】：转速是表征旋转机械健康状况、进行故障诊断、制定必要维修策略的重要参数之一。旋转机械在能源、化工、电力、冶金等行业的机械设备中占有举足轻重的地位,转速的实时、准确测量对保证旋转机械的正常运行具有重要的现实意义。然而,现有的转速测量仪表在精度、价格、可靠性等方面均存在一定的局限性,特别是在复杂、恶劣的工业环境下难以达到长期、稳定、准确的测量,因此,有必要利用新原理、新方法研制更加优良的测量仪表。同时,静电检测技术在气固两相流参数检测及航空发动机尾气监测等领域的成功应用,促进了这项技术的迅速发展。本文创新性地探索了基于静电感应原理的转速测量新方法,通过检测运动部件表面的静电荷,获取旋转机械的转速信息。针对传感器感应机理建模、传感器优化设计、转速测量系统开发、测量系统性能评估等方面进行了较为深入的研究：(1)首次将静电检测技术应用于转速测量领域,提出了基于静电传感器的转速测量方法。根据被测转轴和安装环境的限制,具体分为三种测量方式：基于单传感器和信号自相关技术的转速测量；基于双传感器和信号互相关技术的转速测量；基于多传感器和数据融合技术的转速测量。(2)针对静电传感器转速测量系统的物理模型,基于点电荷的思想建立了条形静电传感器的数学模型。深入研究了传感器的空间灵敏度、频率响应、空间滤波长度、带宽等感应特性,为静电传感器的性能分析和优化设计提供了坚实的理论基础。通过实验模拟点电荷在旋转过程中产生的三维空间静电场,分析了条形静电传感器的输出特性,并与模型结果对比,从而验证了测量方法的正确性和数学模型的有效性。(3)基于静电传感器转速测量原理,设计传感器感应单元、微弱信号检测电路、相关信号处理算法以及多数据融合算法,实现转速测量系统的集成。该系统不仅能够实时显示旋转速度、信号的静电强度和相关系数,而且能够记录这些测量参数信息,有助于进一步分析系统的可靠性和稳定性。(4)针对静电传感器转速测量系统的三种组态(单传感器、双传感器和多传感器)进行性能评估。通过一系列的实验研究,分别确定测量系统在每种组态下的测量范围、精确度、重复性、稳定性。并逐一对静电电极到转轴表面的距离、旋转速度、被测转轴材料、转轴大小、表面粗糙度等因素对测量系统性能的影响进行量化分析。最终形成精确、快速、经济、可靠的新型旋转机械转速测量系统。
[Abstract]:Rotational speed is one of the important parameters to characterize the health condition of rotating machinery, to diagnose faults and to formulate necessary maintenance strategies. The mechanical equipment in metallurgy and other industries plays an important role. The real-time and accurate measurement of rotating speed is of great practical significance to ensure the normal operation of rotating machinery. However, the existing rotating speed measuring instruments are accurate. Price, reliability and other aspects have some limitations, especially in the complex, harsh industrial environment is difficult to achieve long-term, stable, accurate measurement, therefore, it is necessary to use the new principles. At the same time, electrostatic detection technology has been successfully applied in the fields of gas-solid two-phase flow parameter detection and aero-engine tail gas monitoring. In this paper, a new method of measuring rotational speed based on electrostatic induction principle is explored, which detects the static charge on the surface of moving parts. According to sensor induction mechanism modeling, sensor optimization design, speed measurement system development. In this paper, the performance evaluation of measuring system has been deeply studied. (1) Electrostatic measurement technology has been applied to the field of rotational speed measurement for the first time. This paper presents a speed measurement method based on electrostatic sensor, which is divided into three measuring methods according to the limits of the measured rotation shaft and installation environment: the speed measurement based on single sensor and signal autocorrelation technology; Speed measurement based on dual-sensor and signal cross-correlation technology; Based on multi-sensor and data fusion technology, the rotational speed measurement is based on the physical model of electrostatic sensor speed measurement system. Based on the idea of point charge, the mathematical model of strip electrostatic sensor is established, and the sensing characteristics of the sensor, such as space sensitivity, frequency response, spatial filter length, bandwidth and so on, are studied in depth. It provides a solid theoretical basis for the performance analysis and optimization design of the electrostatic sensor. The output characteristics of the strip electrostatic sensor are analyzed by simulating the three-dimensional electrostatic field generated by the point charge during the rotation process. Compared with the results of the model, the correctness of the measurement method and the validity of the mathematical model are verified. Based on the principle of speed measurement of electrostatic sensor, sensor induction unit and weak signal detection circuit are designed. Correlation signal processing algorithm and multi-data fusion algorithm to realize the speed measurement system integration, the system can not only real-time display rotation speed, signal electrostatic intensity and correlation coefficient. Moreover, it can record the information of these measurement parameters, which is helpful to further analyze the reliability and stability of the system. (4) three configurations (single sensor) for the speed measurement system of electrostatic sensor. Through a series of experimental studies, the measurement range, accuracy and repeatability of the measurement system under each configuration are determined respectively. Stability. The influence of the distance from the electrostatic electrode to the surface of the shaft, the speed of rotation, the material of the measured shaft, the size of the shaft, the surface roughness and other factors on the performance of the measuring system were analyzed one by one. Finally, the accuracy of the measurement system was obtained. Fast, economical and reliable new rotating speed measuring system.
【学位授予单位】：华北电力大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TH165.3

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