机械设备运行速度和振动的静电检测机理与方法研究

Measurements of speed and vibration are essential for the normal operation of mechanical devices and systems. Existing instruments for such purposes have limitations in terms of precision, cost, reliability and so on, therefore better instruments should be developed using new principles and methods. Based on the principle of electrostatic induction, this project explores innovative methods for the measurement of rotational speed, translational speed, radial vibration of rotors and normal vibration of objects in linear motion. State information of the mechanical system will be extracted by detecting the electrostatic charge on the surface of the moving mechanical parts. Theoretical modeling, simulation analysis, optimized design and experimental studies will be conducted to uncover the sensing mechanism and working characteristics of electrostatic sensors. Test rigs will be built and algorithms for weak signal detection, processing and data fusion will be developed. The effects of different factors on the measurement system performance will be studied. Prototype speed and vibration measuring instruments that are precise, fast, reliable and cost-effective will be implemented at the end of the project. The theoretical and experimental studies of the project will provide not only new theories, methods and techniques for the condition monitoring of mechanical systems, but also theoretical foundations for sensing mechanism, performance analysis and optimized design of electrostatic sensors. The instruments to be developed in this project are applicable to a wide range of industries such as energy, chemicals, manufacturing and transportation, demonstrating a bright application prospect.

速度与振动的测量对保证机械设备的正常运行具有重要的意义,现有的测量仪表在精度、价格、可靠性等方面存在一定的局限性，有必要利用新原理、新方法研制更加优良的测量仪表。本项目针对机械设备转动速度、平动速度、转子径向振动以及平动物件法向振动的测量，探索一种基于静电感应原理的新方法，通过检测运动部件表面的静电荷获取机械系统的状态信息。本项目通过理论建模、仿真分析、优化设计、实验研究等途径深入揭示静电传感器的检测机理及其工作特性，结合实验装置设计微弱信号检测、处理及融合算法，并研究不同因素对测量系统性能的影响，最终形成精确、快速、可靠、经济的新型速度与振动测量方法。所开展的理论与实验研究可为机械系统状态监测提供崭新的理论、方法和技术手段，更可为静电传感器的传感机理和相应检测系统的性能分析和优化设计提供重要的理论基础。研究成果可应用于能源、化工、制造、交通等多个领域，具有广阔的应用前景。

机械设备零部件的运动使其表面携带静电荷并引起周围电场的波动，位于该电场内的金属电极上感应电荷的变化，能够反映零部件的运动状态。基于上述原理，本项目提出基于静电感应的新型机械设备状态监测方法，通过理论建模、仿真分析、优化设计、实验研究等途径深入揭示静电传感器的检测机理并分析其工作特性，实现了转子旋转速度、径向振动以及传动带纵向速度、横向振动的在线精确测量。主要研究内容包括：1）提出了进行机械设备状态监测的静电传感器物理模型，基于点电荷静电感应原理建立了静电传感器的数学模型及有限元数值仿真模型，分析了其灵敏度空间分布、空间滤波效应、频率响应、信号带宽等特性，并实现了结构的优化设计。2）分别采用跨阻放大器和电荷放大器设计感应电荷信号的调理电路，基于双层印制电路板实现了智能静电传感器样机；提出了静电信号自相关、互相关及数据融合算法实现速度测量；提出了频谱分析、Hilbert变换、工作变形频率响应函数等方法实现振动频率、工作变形等参数的测量。3）搭建了进行转子旋转速度、径向振动及传动带纵向速度、横向振动、工作变形测量的实验装置，通过实验研究了电极形状、尺寸、电极之间以及电极到被测物体距离、被测物体尺寸、材料特性及表面粗糙度、环境湿度等不同因素对测量结果准确性、可重复性的影响，系统评估了静电传感器的测量性能。通过开展上述研究，本项目对基于静电感应的机械设备速度与振动检测机理有了深入的认识，形成了较为系统的新型机械系统状态监测理论和方法，实现了精确、快速、可靠、经济的新型机械系统状态监测仪表。