【作者】 杨洁；

【导师】 吴博达； 赵宏伟；

【作者基本信息】 吉林大学 ， 机械制造及自动化， 2012， 硕士

【摘要】 随着科技的发展，针对原位微纳米力学测试仪器、扫描探针显微镜、三坐标测量仪等精密测试仪器的微小载荷信号的精密检测是非常重要，因此研究一种结构尺寸微小、精度和集成化均较高的微力传感器具有重要实际意义。本文将工作的重点放在微小载荷信号检测单元的设计与实验分析上，结合相关学科知识，基于压电元件的优点和柔性铰链的特点，研制了一种位移放大机构和自检测等功能为一体的具有较高精度、较宽测试范围、结构轻巧的应变型微力检测单元，同时结合相关定律，还实现了精密位移信号的同步检测功能。首先，介绍了用于检测位移和载荷力信号的传感器的国内外研究进展，结合国内外进展指出各种测量方式在实际应用中存在测量维数单一、串联其他传感器误差大等缺点而不适用于在有限空间中测量微小载荷，所以自主研发一种可同时检测位移载荷和力载荷的高精度和高度集成化的检测单元具有重要的意义。然后，介绍了检测单元的一个测量原理和一个关键技术。介绍了柔性铰链技术，分析了直圆型柔性铰链的优点，建立了力学分析模型，推导了理论柔度计算公式，对柔性铰链机构的设计与优化提供了依据。推导了不同布片方式时测量电路的输出电压，建立了在受力状态下应变与载荷、结构尺寸之间的关系；接着着重对检测单元的主要部件进行了设计与分析，包括载荷自检测模块的设计分析和压入模块的设计分析。利用有限元分析软件ANSYS10.0对检测单元的关键模块进行了静力学分析和模态分析，得到了各自应力分布图以及前六阶振型图。分析仿真结果得出结论：载荷自检测模块和压入模块具有较好的强度，并能在低频状态下良好的工作。最终设计出了以压电叠堆为动力源、柔性铰链为精密传动结构、应变片为检测结构信号的应变型微小位移/载荷力检测单元，并建立了相应的CATIA的模型图。最后，对检测单元在开环工作状态下的放大倍数、位移载荷、力载荷、刚度、分辨率和测试范围等性质进行了试验研究。试验结果表明：载荷自检测模块的放大倍数和刚度满足设计要求，整个检测单元的位移载荷和力载荷的检测结果在工作状态下输出特性良好，压入模块在加载过程中的分辨率为20nm，最大输出位移为196.24μm，最大输出力为69.39N；载荷自检测模块的刚度为44.28KN/m，分辨率为1mN。整个检测单元在空载情况下，加载卸载曲线具有良好的重复性。另外，又分析了试验过程中的主要误差因素，并针对每个影响因素给出了解决方案。仿真和试验结果表明本文设计的应变型微小位移/载荷力检测单元已经达到了一定的精度，但其误差影响需进一步的改进。更多还原

【Abstract】 With the development of science and technology, in view of the in situ mechanicstest, scanning probe microscopy, three coordinates measuring instrument and otherprecision monitoring instruments, tiny load of force signal precision testing is veryimportant.Therefore, research and development a miniature, high-precision andhigh-integrated micro-force sensor has a very urgent subject of great practicalsignificance. Based on the advantages of Piezoelectric element as well as thecharacteristic of flexible hinge, this paper will put the key work for small signaldetection unit load power design and experiment analysis.The sensor relates tomechanics, testing technology, piezoelectric, electrical, mechanical and other relatedknowledge. Integrating displacement amplification platform and self-sensing function,the uint takes advantages of high accuracy, wide testing range and light weightstructure.First, the tiny force measurement methods of the domestic and foreign researchprogress are introduced and the advantages and disadvantages of each measurementmethod are given. There are some shortcomings during methods, such as singledimension measurement, a higher of deviation with series other sensors and so on. Sothey are not suitable to carry out tiny force measurement in a limited space. And a kindof high-precision and high-integrated sensor which can test force load anddisplacement load at the same time has the vital significance.Then, the one measurement principle and the one key technology of uint areintroduced. The flexible hinge technology is introduced. The advantages of Straightcircular flexure hinge is analyzed. Mechanics analysis model of Straight circularflexure hinge is established and the formula of theoretical flexibility is deduced whichprovides reference for the design and optimize of flexible hinge. The output voltage indifferent ways of measuring circuit is deduced. The relationship among State strain, load and the structure size in the stress is established.Then, main components of the sensor mainly including self-detection unit of loadand head unit are designed and analyzed. Static analysis and modal analysis is carriedout for these components by finite element analysis software ANSYS10.0. And resultsof deformation and stress distribution as well as the first six order frequencies andmode shapes are obtained under different loading conditions. Through these resultsintensity and frequency response of these key parts are analyzed and the conclusion isthat self-detection unit of load and head unit have good strength and stability for lowfrequency work. Finally a sensor based on Piezoelectric stack as power source, flexiblehinge as precision transmission structure, strain gauge as the detection signal of strainis designed and its CATIA model is also established.Finally, the experimental researches contain magnification, displacement of theload, force of the load, stiffness, resolution, and test range in open loop. Experimentalresults indicate that magnification and stiffness of self-detection unit of load meet thedesign requirements, displacement of the load and force of the load in workingcondition have a good output characteristics, the resolution of indentation unit is20nm,the biggest displacement load is196.24μm, the biggest force load is69.39N, thestiffness of self-detection unit of load is44.28KN/m, the resolution is1mN. The curveshas a good reproducibility during loading and unloading with no load of the test uint.The thesis analyzes the experimental error of testing uint and puts forward somemeasures to reduce the error. The results show that the sensor presented in this papercan be able to reached a certain degree of accuracy but the error influence of its largerneed to be improved.更多还原