Determination of the Optimal Parameters for Freeform Surface Measurement and Data Processing in Reverse Engineering

2003 ◽  
Vol 21 (9) ◽  
pp. 678-690 ◽  
Author(s):  
F.-J. Shiou ◽  
Y.-F. Lin ◽  
K.-H. Chang
Keyword(s):  
Data Processing ◽  
Reverse Engineering ◽  
Freeform Surface ◽  
Surface Measurement ◽  
Optimal Parameters

Study on Elliptic Filters in Airborne Gravity Data Processing

2013 ◽  
Vol 341-342 ◽  
pp. 999-1004
Author(s):  
Wei Zhou ◽  
Ti Jing Cai
Keyword(s):  
Data Processing ◽  
Gravity Data ◽  
Airborne Gravity ◽  
Optimal Parameters ◽  
Evaluation Indicator ◽  
Filter Order ◽  
Upper Limit ◽  
Optimal Value ◽  
Low Pass ◽  
Stopband Attenuation

For low-pass filtering of airborne gravity data processing, elliptic low-pass digital filters were designed and filtering influences of the elliptic filter order, upper limit passband frequency, maximal passband attenuation and minimal stopband attenuation were studied. The results show that the upper limit passband frequency has the greatest effect on filtering among four parameters; the filter order and the maximal passband attenuation have some influence, but instability will increase with larger order; the effect of the minimal stopband attenuation is not obvious when reaching a certain value, which requires a combination of evaluation indicator accuracy to determine the optimal value. The standard deviations of discrepancies between the elliptic filtered gravity anomaly with optimal parameters and the commercial software result are within 1mGal, and the internal accord accuracy along four survey lines after level adjusting is about 0.620mGal.

Two-step carrier-wave stitching method for aspheric and freeform surface measurement with a standard spherical interferometer

2018 ◽  
Vol 57 (17) ◽  
pp. 4743 ◽  
Author(s):  
Qun Hao ◽  
Shaopu Wang ◽  
Yao Hu ◽  
Yifeng Tan ◽  
Tengfei Li ◽  
...  
Keyword(s):  
Freeform Surface ◽  
Surface Measurement ◽  
Carrier Wave

Integrating Freeform and Feature-Based Fitting Methods

2004 ◽  
Author(s):  
H. James de St. Germain ◽  
David E. Johnson ◽  
Elaine Cohen
Keyword(s):  
Reverse Engineering ◽  
Surface Fitting ◽  
General Purpose ◽  
Freeform Surface ◽  
Domain Expert ◽  
Coordinate Measurement ◽  
Reverse Engineer ◽  
Model Based ◽  
Cad Models ◽  
Feature Based

Reverse engineering (RE) is the process of defining and instantiating a model based on the measurements taken from an exemplar object. Traditional RE is costly, requiring extensive time from a domain expert using calipers and/or coordinate measurement machines to create new design drawings/CAD models. Increasingly RE is becoming more automated via the use of mechanized sensing devices and general purpose surface fitting software. This work demonstrates the ability to reverse-engineer parts by combining feature-based techniques with freeform surface fitting to produce more accurate and appropriate CAD models than previously possible.

DIGITAL ZENITH CAMERA FOR VERTICAL DEFLECTION DETERMINATION

2012 ◽  
Vol 38 (4) ◽  
pp. 123-129 ◽  
Author(s):  
Māris Abele ◽  
Jānis Balodis ◽  
Inese Janpaule ◽  
Ieva Lasmane ◽  
Augusts Rubans ◽  
...  
Keyword(s):  
Data Processing ◽  
Digital Imaging ◽  
High Accuracy ◽  
Reference Star ◽  
Research Groups ◽  
Vertical Deflection ◽  
Digital Imaging Technology ◽  
Prototype Instrument ◽  
Automated Determination

Recent accomplishments in advancement of accurate astrometric reference star catalogues, development of digital imaging technology, high accuracy tiltmeter technology, and geocentric coordinate availability provided by GNSS, have made possible accurate, fast and automated determination of vertical deflections using astrometric methods. Zenith cameras for this kind of measurements have been developed or are being developed by several research groups. The paper describes a research project by Institute of Geodesy and Geoinformation, intended to design a portable digital zenith camera for vertical deflection determination with 0.1” expected accuracy. Camera components are described, proposed data processing algorithm and preliminary results, obtained with prototype instrument, are presented.

The PPP data processing algorithm to create geodetic networks

2021 ◽  
pp. 464-468
Author(s):  
A.D. Tikhonov ◽  
A.A. Kochiev
Keyword(s):  
Data Processing ◽  
Processing Algorithm ◽  
Navigation Systems ◽  
Geodetic Networks ◽  
Data Processing Algorithm ◽  
Global Navigation ◽  
Global Navigation Systems

The article deals with determination of coordinates using global navigation systems, and application of the PPP data processing algorithm to obtain coordinates. The authors conducted an experiment illustrating the algorithm accuracy.

Determination of optimal parameters of the tuned mass damper to reduce the torsional vibration of the shaft by using the principle of minimum kinetic energy

2018 ◽  
Vol 233 (2) ◽  
pp. 327-335 ◽  
Author(s):  
Duy-Chinh Nguyen
Keyword(s):  
Kinetic Energy ◽  
Torsional Vibration ◽  
Damping Ratio ◽  
Vibration Reduction ◽  
Tuned Mass Damper ◽  
Optimal Parameters ◽  
Lagrangian Equations ◽  
Tuning Ratio ◽  
Mass Damper

In this paper, an analytical method is presented to determine the optimal parameters of the symmetric tuned mass damper, such as the ratio between natural frequency of tuned mass damper and shaft (tuning ratio) and the ratio of the viscous coefficient of tuned mass damper (damping ratio). The optimal parameters of tuned mass damper are applied to reduce the torsional vibration of the shaft based on consideration of the vibration duration and stability criterion. The dynamic equations of the shaft are provided via Lagrangian equations, and the optimal parameters of tuned mass damper are derived by using the principle of minimum kinetic energy. Analytical and numerical examples are implemented to verify the reliability of the proposed method. The analytical and numerical results indicate that the optimal parameters of tuned mass damper have significant effects in the torsional vibration reduction of the shaft.

Determination of global kinetic parameters by optimization procedure using burning velocity measurements

2018 ◽  
Vol 13 (6) ◽  
pp. 50
Author(s):  
Gleb V. Grenkin ◽  
Alexander Yu. Chebotarev ◽  
Valeri I. Babushok ◽  
Sergey S. Minaev
Keyword(s):  
Kinetic Parameters ◽  
Equivalence Ratio ◽  
Reaction Rate ◽  
Functional Dependence ◽  
Burning Velocity ◽  
Optimization Procedure ◽  
Optimal Parameters ◽  
Velocity Measurements ◽  
Equilibrium Calculations

The optimization procedure was developed to derive the global kinetic parameters using experimental dependence of burning velocity on the equivalence ratio. The simple model of laminar premixed flame propagation with assumed constant parameters was used to demonstrate the features of the suggested procedure. The suggested method allows finding optimal parameters for the defined functional dependence of the reaction rate on the temperature and reactant concentrations. The dependence of combustion adiabatic temperature on equivalence ratio is assumed to be known from the flame equilibrium calculations. The global kinetic parameters of combustion reaction were determined for methane, ethylene and propane mixtures with air on the basis of experimental data on burning velocity as function of the equivalence ratio. The calculated overall kinetic parameters are compared with parameters obtained by other methods within similar global model.

Determination of Ultrasonic Welding Optimal Parameters for Thermoplastic Material of Manufacturing Products

2013 ◽  
Vol 64 (1) ◽  
Author(s):  
Rashiqah Rashli ◽  
Elmi Abu Bakar ◽  
Shahrul Kamaruddin
Keyword(s):  
Electronic Device ◽  
Low Cost ◽  
Near Field ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Field Configuration ◽  
Welding Parameters ◽  
Optimal Parameters ◽  
Thermoplastic Material

Ultrasonic welding had been widely used in various manufacturing industries such as aviation, medical, electronic device and many more. It offers a continued safe operation, faster and also low cost as it able to join weld part less than one second and also simple to maintain the tooling devices. Though ultrasonic welding brings a lot of advantages in assembly especially in thermoplastic material of manufacturing product, it also has a dominant problem to be deal with. The problem in ultrasonic welding is poor weld quality due to improper selection of ultrasonic welding parameters especially in near field configuration. Thus, an optimal combination of parameters is crucial in order to produce good quality weld assembly for this configuration. In this paper, ultrasonic welding process, ultrasonic weld joint defects and determination of optimal parameters for thermoplastic material had been discussed thoroughly. 

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