【作者】 郧建平；

【导师】 谢铁邦；

【作者基本信息】 华中科技大学 ， 测试计量技术及仪器， 2008， 博士

【摘要】 表面形貌的测量方法通常可分接触式和非接触式两种,这两种方法在许多方面具有互补性且各自有自己的应用领域,因此有必要将两种测量技术集合组成一种混合型的测量仪器。本文以白光干涉测量技术为基础,以Linnik干涉显微镜为主体构成了一种新型的接触和非接触两用表面形貌测量系统。下面对论文的主要创新与研究内容进行概述和总结。提出了一种基于白光干涉测量技术的接触式表面形貌测量系统。利用波动理论点扩散函数的方法建立了接触式测量的数学模型,并讨论了接触式测量系统的灵敏度、非线性误差等特性。提出了一种接触和非接触两用表面形貌测量系统,两种测量方法均以白光干涉测量技术为基础,结构上均以Linnik干涉显微镜为主体。与其它同类测量系统相比,本系统具有资源共用程度高、测量精度高、成本低、应用广泛的特点。由于采用了白光干涉测量技术,没有单色光干涉测量系统所具有的相位模糊问题,与垂直位移扫描工作台和x-y扫描工作台相结合,接触式和非接触式测量系统均可进行大量程的测量。对非接触式测量的条纹识别方法进行了分析和总结,提出了非接触式测量的零级条纹判别采用两种求解方法,分别用于满足实际测量中对测量速度和测量精度要求不同的多种场合。对测量系统的主要部件进行了设计。讨论了白光光源的特性,提出了一种白光干涉仪中组合光源的设计判断标准,推导出了双组合光源和三组合光源的简洁设计公式,计算机模拟结果表明,本设计方法可以有效地提高白光干涉图形中零级条纹的识别精度。对接触式测量中杠杆机构的十字弹性支承进行了设计,并对杠杆机构的动态特性进行了分析。推导出了表面粗糙度与测量速度和测量力之间的关系,对接触式测量设置了三挡扫描速度,能够满足对不同粗糙度表面进行快速、有效的测量要求。对Linnik干涉显微镜中分光棱镜产生的误差进行了讨论,设计了工作台计量光栅的处理电路及其光栅信号的软件处理方法。讨论了整个测量系统的动态特性、滤波特性、测量的稳定性和重复性等特性。分析了接触式测量系统和非接触式测量系统的测量误差,分别设计了杠杆机构动态特性的标定方法以及接触式测量和非接触式测量的标定方法,给出了相应的标定结果。更多还原

【Abstract】 In surface morphology there are two main families of technology, the first of which requires contact between a stylus tip and the surface, whereas the second is non-contact technique without any contact between the sensor and the object. It is known that these two types of instrument are complementary to each other in many aspects and each of them has their own application areas. So it is needful to integrate the two techniques into one surface measuring instrument. A novel hybrid instrument capable of contact and non-contact measurements with large range is developed, and both measurement systems are based on a Linnik interference microscope and on white-light interference measuring techniques. The creative points and main research contants are as follows.A contact surface profile measurement system which is based on white-light interference measuring technique is proposed. The mathematic model for the contact measuring method is established by wave theory, the sensitivity and the non-linear measuring error are discussed accordingly.A hybrid surface profile measurement system capable of contact and non-contact measurements with large range is proposed. Both measuring methods are based on white- light interference measuring technique, and both systems are built on Linnik microscope configuration. Compared with other counterparts, the system has a simpler structure and a lower cost, and is of high accuracy and suitable for a wide range of applications. As adopting white-light interference measuring technique, the ambiguity presented in conventional monochromatic interferometers is not present for both contact and non-contact measurements, and it can be used for large range measurements in combination with the vertical scanning stage and x-y stage. On the basis of analysis and summary for fringe identifying techniques of non-congtact measurement, it is proposed that two methods of determination of zero-order fringe are used in the system to respectively meet the demands for different measuring speeds and accuracy ranges.The main parts and assemblies of the system are designed and analysed. After discussing the characteristics of white-light sources, the simple design formula for two-synthesized source and three -synthesized source are obtained in accordance with the proposed judgment criterion, and the design effects are simulated with computer. The results of computer simulation demonstrate that the use of the synthesized sources with the optimized parameters results in the more accurate determination of zero-order fringe. The cross-spring pivot of the lever mechanism in the contact measuring system is designed, and the dynamic characteristics of the lever mechanism are studied. On the basis of the relationship deduced between the traverse speed and the roughness of test surface and between the measuring force and the roughness, three grades of the traverse speeds are setted for the system, which can be used for the rapid and effective measurement of the surfaces of different roughness. The processing circuit and a software method of fine dividing of grating sensor in the stages are designed, and the error analysis for the beamsplitter in Linnik interference microscope is discussed.The dynamic characteristic, the filter characteristic, the stability and the repeatability of the system are also discussed. The errors of the contact and noncontact measuring systems are analysed, respectively. The calibration methods for the dynamic characteristics of the lever mechanism and for the contact and noncontact measurements are designed seperately, and the calibration results for them are also shown.更多还原