在线检测超精细表面微观形貌的激光轮廓仪

介绍一种可用于在线和在位检测的高分辨力激光轮廓仪,此仪器具有很高的共模型抑制比和同类型仪器中最小的形状误差,分辨力优于0．2nm(Ra)。可以摆放在金刚石车床的刀架上测量超精密加工表面微观形貌。     

用于超光滑表面无损检测的光学轮廓仪

所述的光学轮廓仪是利用双焦透镜产生的偏振光束经被检面反射后形成了一共路干涉体系，因此该干涉体系可对超光滑表面做非接触无损检测而无需标准参考面；同时，利用双通道电子共模抑制技术可有效地抑制系统的各类噪声；计算机控制测量，即时给出表面粗糙度参数，测量结果与计量用ＷＹＫＯ轮廓仪比对，结果吻合。仪器特别适合于均方程极值Ｒｑ为纳米及亚纳米量级的表面的测试，尤其是软质金属材料及膜层表面。其横向分辨率为１μｍ，纵向分辨率为０．１ｎｍ。     

Φ1.07 m,F/1.5非球面反射主镜在位检测塔的设计与应用

大型非球面反射主镜的检测,国内通常采用离线的卧式检测.由于气流、温度变化以及地基振动等环境因素,容易影响检测的可靠性和重复性.国外在大型非球面反射主镜的检测中普遍采用在位或离线的立式检测塔.本文针对Φ1.07 m,F/1.5非球面反射主镜在加工中的检测,在有限的加工环境中设计了一套分体式立式在位检测塔,由一个四维工作台调节平面反射镜来转折光路、一个五维工作台调节补偿器和一个五维工作台调节干涉仪以满足测量中自由度的调节需要.用有限元分析软件ANSYS对立式塔进行了应力和应变的设计分析以检验其刚性、重心位置和变形情况,以及避免与工件转台产生共振的模态分析.该检测塔在Φ1.07 m,F/1.5非球面反射主镜加工过程中得以用于检测测量,获得了稳定的干涉图和良好的重复性,工件接近完工时的检测结果为PV=0.3133λ.RMS=0.0243..     

表面粗糙度干涉图像处理系统

介绍了表面粗糙度干涉图像处理和该系统以静态干涉图像处理技术对表面粗糙度检测的过程。该系统通过对一帧白光干涉图像的处理，可对Ｒａ值≤０．２μｍ的多刻线样板，试件表面粗糙度绝对、非接触、快速、自动地测量；该系统通过对白光和纳光二帧干涉图象的联合处理，以白光定位、纳光定度可对沟槽深度Ｈ≤５μｍ的标准单位刻线深度绝对，非接触，准确地测量。     

超光滑表面轮廓的绝对测量

本文提出了一种测量超光滑表面轮廓的绝对测量方法。采用微分干涉显微镜直接测量表面轮廓的差分，从而无需使用标准参考反射镜，并能有效在抑制机械振动等环境干扰对测量结果的影响。在不采取隔振和恒温等环境控制措施的一般实验室场合下，就可达到优于０．１ｎｍ的垂直分辨率和０．１５ｎｍ的表面轮廓重复测量精度。     

大型结构件数控加工在位计量检测技术研究

在位计量检测以加工机床为硬件载体,实现加工、测量一体化,对提高产品质量和生产效率有重要意义。介绍了数控加工在位计量检测系统的组成与方案的实现过程,对系统的性能进行了现场试验,结果表明大型结构件数控加工在位计量检测系统可对大型数控加工零件工艺过程中的尺寸和形位误差进行准确在位测量,大大缩短了大型数控加工件的定位时间,有效提高了一次装夹加工的效率和合格率,避免了工件的二次装夹,降低了生产成本,为数字化装配提供有力保证。     

一种干涉测温的新方法

针对前后表面平行抛光的物质，干涉测温是一种非常有效的非侵入性测量方法，本文中对常规干涉测温法进行改进，提出了一种新方法－－弱相干法，该方法利用光源的弱相干性抑制背景反射光，选择所需信号光进行干涉测量，从而提高测量精度。文中描述了弱相干法的基本原理及相应的实验。     

大型镜面大误差范围相位恢复在位测量研究

研究了一种基于相位恢复技术的新型镜面测量方法,用于测量大型光学镜面研抛加工过程中较高较陡的面形误差,为光学镜面加工中误差收敛的过渡阶段提供可靠的定量在位测量方法。文中构建了基于离焦光场的相位恢复测量系统并设计适用于大误差检测的相位恢复算法。分析了各种误差因素以及系统测量精度以及测量范围。对一面口径150mm球面反射镜进行了在位测量实验。相位恢复测量与干涉测量结果一致。理论分析和实验都表明该方法切实可行,检测范围和相对精度满足加工要求,具有良好的应用前景。     

激光自混频干涉法测量表面粗糙度的理论分析

设计了一种半导体激光自混频干涉法测量表面粗糙度的实验，对半导体激光自混频干涉法测量表面粗糙度中的干涉效应进行了理论分析，推导了干涉信号与表面粗糙度的数学关系式，讨论了影响测量信号的因素。实验结果表明，随着加工表面粗糙度的降低，反射光的强度逐渐增加，被测物体表面的反射率越高，越有利于测量。     

X小角散射中的干涉效应

在X小角散射中，多用Guinier近似法求粒度分布，一般都认为角度越小，则近似程度越高，但实际上这个近似是在忽略了粒子间干涉效应的前提下得到的，而角度越小则干涉效应就越大，因而不能认为角度越小越好。且随着测量技术的提高，可测的角度也越来越小，测得的干涉部分就越多，因而不能用最小角处的数据，而应用无干涉的稍大角区的测量信息，或设法将干涉部分去掉。     

Measurement of surface topography of magnetic recording materials through computer analyzed microscopic interferometry

A recently developed surface characterization technique, Computer Analyzed Microscopic Interferometry, is shown to have many applications in the study of magnetic recording surfaces. Three-dimensional and quantitative interferometric images produce very high depth resolution without reducing the field of view. This allows very precise surface roughness and volume measurements.     

利用扭秤进行空间干涉仪的地面测试技术

空间干涉仪作为下一代重力卫星、空间引力波探测计划的核心部件之一,其灵敏度远高于目前电容式读出的惯性传感器。但由于空间干涉仪涉及技术细节过多,需在地面研制阶段接受大量测试,而低频测试频段以及极低噪声环境的苛刻要求成为当前地面测试阶段的最大挑战之一。该文介绍以悬挂扭秤为核心技术的地面测试平台,其在竖直方向可由悬丝平衡地球所带来的引力影响,而在水平方向可模拟准自由落体状态。选用经过特殊设计而成的悬挂扭秤作为测试对象,可将地面测试中的主要噪声——地面振动噪声降低3~4个量级,使得加速度噪声在观测频段可低至10−13 m·s^−2·Hz^−1/2@mHz,已达到目前该频段的测量极限,该技术也是目前国际上公认的空间干涉仪地面研制阶段的最佳测试平台之一。     

The development of machine intelligence in a computational universe

The paper is dedicated to the study of the theoretical and technological development that occurred, in particular in the XX century, in the sector of Artificial Intelligence. According to the theoretical framework of mechanical rationalism, we study how the development of machine intelligence is a continuation, through different means, of the old process of outsourcing of cognitive activities by humans onto parts of their physical environments. Because of this process, an increasingly larger portion of the non-human environment performs perceptive and cognitive activities. From this follows that machine systems, not necessarily humans anymore, are the components of the physical environment that perform measurements on the universe of which the humans are also components. We suggest that the scientific discussion on the topic of AI development could be framed in the context of a more general phenomenon of an increase in the computational and perceptual capabilities of the physical universe, as opposed to a merely human and technological problem. This is because, ever so slightly, humans are being removed from the cognitive processes of technological systems they created, which continue to perceive and think autonomously. The act of machine cognition, or rather, of machine measurements, causes an effect on the environment in which humans live, and ever more so than the human measurements. Finally, we discuss the current approach to the development of viable AI systems that aim at increasing the reciprocal intelligence of humans and machines, rather than the replacement of the former's cognitive faculties by the latter.     

Iterative reverse optimization procedure for calibration of aspheric wave-front measurements on a nonnull interferometer

The accuracy of interferometric measurements made with a nonnull configuration is degraded by test-dependent aberrations. Calibration of the data can be done with reverse optimization methods. An iterative reverse optimization process that improves efficiency and eliminates sensitive merit function weighting issues is described. The process is shown to calibrate a nonnull interferometric measurement of a wave front with more than 200 waves of departure to an accuracy of 0.16 waves peak to valley and 0.02 waves rms.     

Technical limitations to homodyne detection at audio frequencies

Homodyne detection relies on the beat between a relatively strong local oscillator (LO) field at the carrier frequency and a signal beam with sidebands centered around the carrier frequency. This type of signal detection, or signal readout, is widely used in quantum optics applications and is expected to be used in advanced interferometric gravitational wave detectors. We investigate experimentally the limitations to making such measurements in a laboratory environment at audio frequencies. We find that beam jitter noise, electronic noise of the photodetectors, and the LO intensity noise can limit the homodyne detection in this frequency band, and we discuss potential solutions.     

Absolute interferometric testing based on reconstruction of rotational shear

A method, believed to be new, for the absolute interferometric testing of flat or spherical surfaces is presented. It is based on the classic three-flat test, combined with additional measurements of one test piece in different rotational positions. Full-surface absolute maps for each test piece are determined with a data-processing technique based on the rotationally sheared maps of the rotated surface. An optimized numerical reconstruction algorithm employing linear filtering and superposition of the different rotational shear spectra in the angular frequency domain is used to reconstruct the rotationally sheared data. The technique does not require any assumptions about the surfaces under test; has low error propagation, even in the case of high spatial resolution; and is computationally efficient.     

Accuracy of a multiple height-transfer interferometric technique for absolute distance metrology

A multiple height-transfer interferometric technique was developed to increase the absolute distance measurement capability of a metrology system that uses a tunable laser. Using multiple accurately calibrated reference heights, this technique relaxes the requirement of knowing accurate wavelength information for multiple wavelength interferometry while maintaining its advantages. We present an uncertainty analysis, analyze the primary sources of uncertainties limiting the performance of this technique, and discuss how errors can be minimized. Measurement results of 3D images obtained from a variety of objects are presented. The measurement uncertainty is experimentally demonstrated to be 0.3?μm over 50?mm for two discontinuous surfaces with a confidence level of 95% in a lab environment.     

Nanopore gradients on porous aluminum oxide generated by nonuniform anodization of aluminum

A method for surface engineering of structural gradients with nanopore topography using the self-ordering process based on electrochemical anodization of aluminum is described. A distinct anodization condition with an asymmetrically distributed electric field at the electrolyte/aluminum interface is created by nonparallel arrangement between electrodes (tilted by 45°) in an electrochemical cell. The anodic aluminum oxide (AAO) porous surfaces with ordered nanopore structures with gradual and continuous change of pore diameters from 80 to 300 nm across an area of 0.5-1 cm were fabricated by this anodization using two common electrolytes, oxalic acid (0.3 M) and phosphoric acid (0.3 M). The formation of pore gradients of AAO is explained by asymmetric and gradual distribution of the current density and temperature variation generated on the surface of Al during the anodization process. Optical and wetting gradients of prepared pore structures were confirmed by reflective interferometric spectroscopy and contact angle measurements showing the ability of this method to generate porous surfaces with multifunctional gradients (structural, optical, wetting). The study of influence of pore structures on cell growth using the culture of neuroblastoma cells reveals biological relevance of nanopore gradients and the potential to be applied as the platform for spatially controllable cell growth and cell differentiation.     

非球面非零位横向剪切干涉检测与波前重建

本文分析了非球面非零位检测中3种典型的非球面度及其变化率、调整误差、回程误差以及干涉仪系统误差,提出了非球面度变化率是影响检测误差的主要因素,并给出了非球面非零位检测面形加工误差的确定方法.对基于Zernike多项式拟合的最小二乘法和系数转换法进行了对比研究,分析了剪切量和多项式拟合阶数对波前重建精度的影响,并给出了数值模拟结果.为了验证以上方法的可行性及检测精度,针对一单点金刚石车削的抛物面反射镜,利用顶点球作为测试波前进行非零位横向剪切干涉检测,并用最小二乘法进行波前重建.实验结果表明,在非球面度变化率最大的反射镜边缘处面形误差最大,达到0.203μm,研究结果为横向剪切干涉仪用于非球面加工过程中在位检测提供了技术支撑.     

Measurement of transverse permeability using gaseous and liquid flow

Accurate measurement of transverse permeability is important for processes such as resin film infusion and vacuum-assisted resin transfer molding. In these liquid composite molding processes the out-of-plane flow is dominant and thus the transverse permeability is needed for flow prediction. This paper introduces an apparatus to measure saturated permeability for fibrous preforms using both gaseous and liquid flow. The setup creates a uniform one-dimensional flow through-the-thickness of the reinforcement by integrating a high permeability layer on the mold surfaces. A wide range of permeability as a function of fiber volume fraction can be measured in one experiment while applying a known load under a hydraulic testing machine. The system has been designed using process simulation. The measurements using the gaseous medium are comparable to the saturated fluid flow results. The measurement system can also be used to measure changes in dry fabric permeability prior to infusion due to debulking or application of binders on the fabric surface.