scholarly journals Optical In-Process Measurement: Concepts for Precise, Fast and Robust Optical Metrology for Complex Measurement Situations

2021 ◽  
Vol 11 (22) ◽  
pp. 10533
Author(s):  
Ralf B. Bergmann ◽  
Michael Kalms ◽  
Claas Falldorf
Keyword(s):  
Complex Geometry ◽  
Coherence Function ◽  
Optical Metrology ◽  
Light Sources ◽  
Process Measurement ◽  
Geometrical Complexity ◽  
Application Techniques ◽  
Complex Measurement ◽  
Process Measurements ◽  
Self Reference

Optical metrology is a key element for many areas of modern production. Preferably, measurements should take place within the production line (in-process) and keep pace with production speed, even if the parts have a complex geometry or are difficult to access. The challenge for modern optical in-process measurements is, therefore, how to simultaneously make optical metrology precise, fast, robust and capable of handling geometrical complexity. The potential of individual techniques to achieve these demands can be visualized by the tetrahedron of optical metrology. Depending on the application, techniques based on interferometry or geometrical optics may have to be preferred. The paper emphasizes complexity and robustness as prime areas of improvement. Concerning interferometric techniques, we report on fast acquisition as used in holography, tailoring of coherence properties and use of Multiple simultaneous Viewing direction holography (MultiView), self reference used in Computational Shear Interferometry (CoSI) and the simultaneous use of several light sources in Multiple Aperture Shear Interferometry (MArS) based on CoSI as these techniques have proven to be particularly effective. The use of advanced approaches based on CoSI requires a transition of the description of light from the use of the well-known wave field to the coherence function of light. Techniques based on geometric optics are generally comparatively robust against environmental disturbances, and Fringe Projection (FP) is shown to be especially useful in very demanding measurement conditions.

scholarly journals THE INTEGRATED SURVEY OF NARROW SPACES AND UNDERGROUND ARCHITECTURE: THE CASE STUDY OF CAMPANA CAVES BAS-RELIEFS

2019 ◽  
Vol XLII-2/W9 ◽  
pp. 277-282
Author(s):  
P. Clini ◽  
R. Nespeca ◽  
R. Angeloni ◽  
R. Mammoli
Keyword(s):  
High Resolution ◽  
3D Model ◽  
Complex Geometry ◽  
Survey Method ◽  
Light Sources ◽  
Digital Reconstruction ◽  
Historical Importance ◽  
Level Of Knowledge ◽  
Important Basis

<p><strong>Abstract.</strong> Italian Cultural Heritage is rich in fascinating Underground Heritage (UH) to be protected and preserved because of its fragility and historical importance. An accurate and high-resolution 3D model is essential to reach an appropriate level of knowledge to safeguard caves but there are several obstacles to face. Underground data acquisition and following elaborations are problematic due to environmental conditions such as lack of homogeneous light sources, highly absorbing and unstable surfaces, narrow spaces and complex geometry. For these reasons, the integration of different techniques is mandatory to achieve a valid final product that could be an important basis for consolidation, preservation and valorization of the UH. In this paper, an integrated survey method is tested for a realistic digital reconstruction of hypogeal spaces. In addition to outputs for experts of conservation, the creation of multimedia products for a wider audience of non-professionals users is investigated as a way to preserve UH from decay. Thanks to VR, visitors virtually walk through the underground galleries observing and interacting, making accessible also fragile environments with forbidden access due to preservation policies.</p>

AN EMPIRICAL STUDY OF DEVELOPMENT VISUALIZATION FOR PROCUREMENT BY IN-PROCESS MEASUREMENT DURING INTEGRATION AND TESTING

2011 ◽  
Vol 21 (03) ◽  
pp. 367-388
Author(s):  
YOSHIKI MITANI ◽  
HIROYUKI YOSHIKAWA ◽  
SEISHIRO TSURUHO ◽  
AKITO MONDEN ◽  
MIKE BARKER ◽  
...  
Keyword(s):  
Process Model ◽  
Development Process ◽  
Study Data ◽  
Test Phase ◽  
Software Project ◽  
Unit Testing ◽  
Development Activity ◽  
Process Measurement ◽  
Integration Test ◽  
Process Measurements

This study describes a new method of development visualization along with empirical evidence of its usefulness. Typically, development activities such as program design, programming, and unit testing are not disclosed to the procurement organization (project owner). However, during integration and testing, various issues require collaboration between the procurement organization and developers. When this occurs, it is important to make the development process visible. Recent reports indicate the usefulness for project management of various in-process project measurements which allow visualization of the formerly invisible software project progress [1–6]. Based on this background, the authors investigated a case study where in-process measurement during the integration and test phase helped to make development issues visible. In this study, data obtained from the integration and testing phase were compared to a development process model. This model was based on the author's experience, and provided a vivid picture of the development activity. By applying in-process measurements in collaboration during the integration test phase, the development activity was clearly visualized, and the procurement organization understood problems.

The Relationship Between Geometrical Complexity and Process Capability

2015 ◽  
Vol 138 (5) ◽  
Author(s):  
Marc Jr. Lépine ◽  
Antoine S. Tahan
Keyword(s):  
Complex Geometry ◽  
Process Capability ◽  
Mathematical Function ◽  
Mechanical Parts ◽  
Geometrical Complexity ◽  
Simple Geometry ◽  
Proposed Model ◽  
Statistical Behavior ◽  
Lower Complexity ◽  
The Relationship

This paper proposes a new method to estimate the process capability for a profile geometric tolerance as defined by the ASME Y14.5 standard. The novelty of the method is that it uses the known process capability of a given geometry to predict, using the order statistics theorem, new capabilities for different geometries of higher or lower complexity. By considering the geometrical complexity of mechanical parts, a manufacturing process may be capable (e.g., Cpk > 1.5) for parts with simple geometry and incapable (e.g., Cpk < 1) for parts with complex geometry. In the proposed model, the process capability becomes a mathematical function of both the statistical behavior of the process (e.g., expectation and variance) and the geometric complexity of manufactured surfaces. Three experimental case studies are presented to illustrate the usefulness and the validity of the developed model.

Surface Profile Measurement During Turning Using Fringe-Field Capacitive Profilometry

1992 ◽  
Vol 114 (2) ◽  
pp. 234-243 ◽  
Author(s):  
J. L. Garbini ◽  
Sih-Ping Koh ◽  
Jens E. Jorgensen ◽  
Mamidala Ramulu
Keyword(s):  
High Speed ◽  
Surface Profile ◽  
Quantitative Agreement ◽  
Fringe Field ◽  
Profile Measurement ◽  
Sensing Element ◽  
Process Measurement ◽  
Static Profile ◽  
Process Measurements ◽  
Surface Profile Measurement

The use of fringe-field capacitive sensing for surface profile measurement during the turning process is described. Measurements of the local surface height are inferred from variations in a fringe electric field induced between the sensing element and the workpiece. The surface profile is determined from high-speed scanning of the sensing element across the surface. The technique is particularly well-suited to the relatively harsh environment of in-process measurement. We have implemented a system in which profile measurements are made continuously, in real-time, and immediately adjacent to the cutting tool. The results of tests conducted to determine the accuracy and sensitivity of this capacitive profilometer are presented. In-process measurements of surfaces generated by turning with roughness in the range of 0.3 to 4.0 μm were made. Comparisons with static profile measurements made using standard stylus instrumentation are presented, and show quantitative agreement.

Study on Fluid Process Measurement Technology

2008 ◽  
Vol 392-394 ◽  
pp. 688-692 ◽  
Author(s):  
Xu Dong Pan ◽  
Guang Lin Wang ◽  
Ze Sheng Lu ◽  
S. Zou
Keyword(s):  
Complex Shape ◽  
Measuring Method ◽  
Machining Process ◽  
Measurement Technology ◽  
Work Piece ◽  
Good Prospect ◽  
Process Measurement ◽  
Fluid Process ◽  
Process Measurements ◽  
Hydraulic Process

Process Measurement is a measuring method which is accompanied with process of the manufacture of work piece. This paper puts forward a new concept of fluid process measurement, and provides four types of fluid process measurements, which are, pressure pneumatic process measurement, flow pneumatic process measurement, pressure hydraulic process measurement, and flow hydraulic process measurement, and establishes the mathematical and physical modal for them. This paper also provides an example of the application of this measurement method. This measurement has a good prospect, because it can deal with the work pieces with high-precision, complex shape and which are hard to be measured in the machining process.

Spatially Resolved Photoelectron Spectroscopy: Recent Progress and Future Plans

1990 ◽  
Vol 48 (2) ◽  
pp. 388-389
Author(s):  
A. M. Bradshaw
Keyword(s):  
Photoelectron Spectroscopy ◽  
Chemical Reactivity ◽  
Target Material ◽  
Orbital Energy ◽  
Light Sources ◽  
Analytical Technique ◽  
Hartree Fock ◽  
Spatially Resolved ◽  
Koopmans Theorem ◽  
Surface Analytical Technique

X-ray photoelectron spectroscopy (XPS or ESCA) was not developed by Siegbahn and co-workers as a surface analytical technique, but rather as a general probe of electronic structure and chemical reactivity. The method is based on the phenomenon of photoionisation: The absorption of monochromatic radiation in the target material (free atoms, molecules, solids or liquids) causes electrons to be injected into the vacuum continuum. Pseudo-monochromatic laboratory light sources (e.g. AlKα) have mostly been used hitherto for this excitation; in recent years synchrotron radiation has become increasingly important. A kinetic energy analysis of the so-called photoelectrons gives rise to a spectrum which consists of a series of lines corresponding to each discrete core and valence level of the system. The measured binding energy, EB, given by EB = hv−EK, where EK is the kineticenergy relative to the vacuum level, may be equated with the orbital energy derived from a Hartree-Fock SCF calculation of the system under consideration (Koopmans theorem).

Sign in / Sign up

Export Citation Format

Share Document