坐标测量机的溯源与校准规范

讨论了坐标测量机溯源的概念和方法,介绍了新制定的坐标测量机校准规范(报批稿),并与国家标准进行了比较     

Automated feature accessibility algorithm for inspection on a coordinate measuring machine

In this paper, the issue of inspection planning for a coordinate measuring machine (CMM) is addressed. A method is presented for the automation of the probe selection decision, with the ultimate goal of determining the set of workpiece orientations recommended for use on a CMM equipped with an indexable probe. The methodology uses a computer-aided design (CAD) model of the workpiece and a list of tolerance information as input to a feature accessibility algorithm. For each inspection feature, the algorithm generates a feasible set of probe orientations using information about potential probe/workpiece collisions, and computes an estimate of its percentage accessibility.     

Accessibility analysis for automatic inspection in CMMs by using bounding volume hierarchies

Accessibility analysis represents one of the most critical tasks in inspection planning. This analysis determines those probe orientations that can touch an inspection point without collision. This paper presents a methodology based on part discretization and the application of space partitioning techniques (kd-tree) in order to reduce the number of intersection tests between probe and part. A STL model has been used for discretizing the inspection part in a set of triangles, which permits the application of the developed system to any type of part, regardless of its shape and its complexity. Likewise, a recursive ray traversal algorithm has been used in order to speed up the traversal of the kd-tree hierarchical structure and to calculate exclusively the intersection of each probe orientation with those part triangles that can potentially interfere with it. In a further step of the analysis, the real geometry of the probe has been considered. Hence, a simplified model has been developed for each probe component (column, head, touch probe, stylus and tip) using different basic geometrical shapes. Finally, collision-free probe orientations are clustered for minimizing the orientation changes during the inspection process. Furthermore, the applied algorithm allows for determining different valid combinations of clusters. The developed system was applied to two example parts in order to prove that this methodology is adequate for the solution of real cases.     

坐标测量机结构热特性参数的估计

本文提出了一种通过热位移时间序列分析对坐标测量机结构热特性参数进行估计的计算机辅助实验方法。     

Automated equipment for pulse measurement of solid thermal diffusivity

Translated from Izmeritel'naya Tekhnika, No. 8, p. 49, August, 1990.     

Automated instrument for ultrasonic structural analysis

An instrument for measuring the velocity of bulk acoustic waves in solids is described. A small measurement error (∼0.05%) is achieved by implementing a phase technique. Microprocessor-based automation shortens the time for one measurement to 3–5 sec. The instrument can be used for the quality control of solid materials (glass, ceramics, crystals, etc.) in a mass-production environment. Translated from Izmeritel'naya Tekhnika, No. 7, pp. 57–58, July, 1995     

Automated system for measurement of vibration characteristics of small units

An automated system for measurement of vibration characteristics using laser and holographic interferometry is described. Russia. Translated from Izmeritel’naya Tekhnika, No. 12, pp. 41–44, December, 1999.     

Automated photoelastic analysis

Photoelastic stress analysis can be a long and tedious process. However recent and current developments in the field of automated and computer aided photoelastic analysis mean that it is becoming possible to do more complex analysis and to perform it more quickly. This paper provides a survey of these developments and the advances in polariscope design.     

Automated small tilt-angle measurement using Lau interferometry

A technique for a tilt-angle measurement of reflecting objects based on the Lau interferometry coupled with the moire readout has been proposed. A white-light incoherent source illuminates a set of two gratings, resulting in the generation of the Fresnel image due to the Lau effect. The Fresnel image is projected onto a reflecting object. The image reflected from the object is superimposed onto an identical grating, which results in the formation of a moiré fringe pattern. The inclination angle of moiré fringes is a function of tilt angle of the object. Theory and experimental arrangement of the proposed technique is presented and results of the investigation are reported.     

Automated measurement systems utilizing the VXI bus

The capabilities of interface automated measurement systems incorporating the VXI bus are demonstrated. The configurations of four applied VXI systems are described.Translated from Izmeritel'naya Tekhnika, No. 11, pp. 19–22, November, 1994.     

Automated measurement of optical coherence lengths and opticaldelays for applications in coherence-modulated opticaltransmissions

The implementation of an automated system for analysis of coherence length of light and for the measurement of optical delays is reported. This type of measurement is very important for designing coherence-modulated optical transmission systems. Such systems have been studied for the last few years as new potential high-speed optical links useful for point-to-point, local area networks, and bidirectional transmissions, at optical wavelengths around 1300 nm. The main characteristics of coherence-modulated transmissions include the need of using low-coherence optical sources and integrated optics lithium niobate (LiNbO₃) electro-optic retarders. This paper describes the implementation of an automated system allowing the measurement of coherence lengths of semiconductor optical sources and also optical delays as essential data for designing coherence-modulated optical links. The reported results include characterization of commercial low-coherence semiconductor optical sources and integrated optics coherence modulators     

Automated measurement of nitrogen trifluoride in ambient air

We present an analytical method for the in situ measurement of atmospheric nitrogen trifluoride (NF(3)), an anthropogenic gas with a 100-year global warming potential of over 16,000. This potent greenhouse gas has a rising atmospheric abundance due to its emission from a growing number of manufacturing processes and an expanding end-use market. Here we present a modified version of the "Medusa" preconcentration gas chromatography/mass spectrometry (GC/MS) system of Miller, B. R.; Weiss, R. F.; Salameh, P. K.; Tanhua, T.; Greally, B. R.; Mühle, J.; Simmonds, P. G. Anal. Chem.2008, 80 (5), 1536-1545. By altering the techniques of gas separation and chromatography after initial preconcentration, we are now able to make atmospheric measurements of NF(3) with relative precision <2% (1σ) for current background clean air samples. Importantly, this method augments the currently operational Medusa system, so that the quality of data for species already being measured is not compromised and NF(3) is measured from the same preconcentrated sample. We present the first in situ measurements of NF(3) from La Jolla, California made 11 times daily, illustrating how global deployment of this technique within the AGAGE (Advanced Global Atmospheric Gases Experiment) network could facilitate estimation of global and regional NF(3) emissions over the coming years.     

Automated measurement of the refractive index of fluids

A method for automating refractive-index measurements of fluids has been developed. An encoded rotation stage and position-sensitive detector enable automated reading of angles typically acquired by visual means. Two tunable lasers are used to obtain index measurements at ten discrete wavelengths across the visible spectrum. This method has been implemented on a Hilger-Chance refractometer from which the bulk refractive-index values for various transparent fluids have been measured. An index measurement accuracy of better than one part in the fourth decimal place for distilled water and a few parts in the fourth decimal place for higher index fluids is obtained.     

坐标测量机上圆度误差包容评定的算法

本文把最小外接圆、最大内接圆和最小区域圆度误差的评定问题都表述为minimax 问题,并建立线性数学模型,采用统一的方法求解。实践表明本文方法通用、有效、稳定,适用于坐标测量机。     

Automated information measurement systems in the housing and utilities sector

Stages in the development and prospects for using measuring systems are considered. __________ Translated from Izmeritel’naya Tekhnika, No. 7, pp. 63–67, July, 2007.