The Precise Measurement of Free-Form Surfaces1

2002 ◽  
Vol 124 (2) ◽  
pp. 326-332 ◽  
Author(s):  
William Wolovich ◽  
Hassan Albakri ◽  
Hulya Yalcin
Keyword(s):  
Precise Measurement ◽  
State Of The Art ◽  
Coordinate Measuring Machine ◽  
Free Form ◽  
Polynomial Equations ◽  
Implicit Methods ◽  
Practical Applications ◽  
Brown University ◽  
Measuring Machine ◽  
Implicit Polynomial

We outline a new procedure for measuring free-form curves and surfaces using implicit polynomial equations. Such equations have long been known to offer certain advantages over the more traditional parametric methods. However, the lack of general procedures for obtaining implicit polynomial models of higher degree, which precisely represent arbitrary 3-D shapes, have prevented their general use in many practical applications, including rapid and precise metrology. Recent mathematical advances obtained at Brown University, experimentally verified using a state-of-the-art Chameleon coordinate measuring machine, have demonstrated potential advantages of implicit methods for modeling and measuring a variety of manufactured objects.

Research on Digital Modeling about Free-Form Surface with Holes Based on Coordinate Measuring Machine

2011 ◽  
Vol 287-290 ◽  
pp. 2805-2809
Author(s):  
Ming Yu Huang ◽  
Xiu Juan Wu ◽  
Zhong Shi Jia ◽  
Hong Jun Ni ◽  
Jing Jing Lv ◽  
...  
Keyword(s):  
Point Cloud ◽  
Coordinate Measuring Machine ◽  
Free Form ◽  
Model Reconstruction ◽  
Contact Measurement ◽  
Digital Modeling ◽  
Measuring Machine ◽  
Fast Reconstruction ◽  
Free Form Surface ◽  
Free Form Surfaces

Data acquisition and model reconstruction of free-form surfaces with holes were been studied, based on coordinate measuring machines. First, the structural process of the parts was analyzed, the method of combinate contact measurement with non-contact measurement were used to get point cloud; Then the point cloud were been preprocessed, feature curve extracted and solid modeled; Finally, the restructure model was been quality assessed and accuracy assessed. Using the measurement of combinated contact and non-contact can also meet both the precision requirement of key part and the fast reconstruction requirement of non-critical part, which has great significance on that part to fast and accurate reconstruction.

Assessment of Free-Form Surfaces’ Reconstruction Accuracy

2017 ◽  
Vol 24 (2) ◽  
pp. 303-312 ◽  
Author(s):  
Artur Wójcik ◽  
Magdalena Niemczewska-Wójcik ◽  
Jerzy Sładek
Keyword(s):  
Accuracy Assessment ◽  
Coordinate Measuring Machine ◽  
System Structure ◽  
Free Form ◽  
Correction Algorithm ◽  
Reconstruction Accuracy ◽  
Machining Center ◽  
Cad Cam ◽  
Measuring Machine ◽  
Free Form Surfaces

AbstractThe paper presents the problem of assessing the accuracy of reconstructing free-form surfaces in the CMM/CAD/CAM/CNC systems. The system structure comprises a coordinate measuring machine (CMM) PMM 12106 equipped with a contact scanning probe, a 3-axis Arrow 500 Vertical Machining Center, QUINDOS software and Catia software. For the purpose of surface digitalization, a radius correction algorithm was developed. The surface reconstructing errors for the presented system were assessed and analysed with respect to offset points. The accuracy assessment exhibit error values in the reconstruction of a free-form surface in a range of ± 0.02 mm, which, as it is shown by the analysis, result from a systematic error.

scholarly journals The accuracy of calculating form deviations of selected free-form surfaces

Mechanik ◽  
2017 ◽  
Vol 90 (11) ◽  
pp. 1035-1037
Author(s):  
Marek Magdziak ◽  
Andrzej Kawalec
Keyword(s):  
Coordinate Measuring Machine ◽  
Measuring System ◽  
Free Form ◽  
Experimental Investigations ◽  
Simulation Studies ◽  
Numerical Investigations ◽  
Measuring Machine ◽  
Coordinate Measurements ◽  
Simulation Results ◽  
Free Form Surfaces

The possible reason for the incorrect form deviations calculated using an algorithm available in the selected software of coordinate measuring machine was identified. This method is available in the Calypso software and it is based on local deviations calculated at nominal points. The analysis was made for the selected examples of free-form surfaces. There are presented the results of numerical investigations based on simulations of coordinate measurements of selected object. The measured points were generated with assumed values of scatter in relation to the nominal profiles of the analyzed product. The simulations were made using 3 selected methods for computing the form deviations and various distances between the measured points. In order to verify the results of simulation studies there were made experimental investigations. The experimental investigations were done using selected coordinate measuring system and chosen measurement parameters. The results of performed measurements confirm the simulation results.

Loaded TCA of Measured Tooth Flanks for Lapped Hypoid Gears

2007 ◽  
Author(s):  
Kohei Saiki ◽  
Keiichiro Tobisawa ◽  
Masaki Kano ◽  
Yasuharu Ohnishi ◽  
Takashi Kusaka
Keyword(s):  
Coordinate Measuring Machine ◽  
Contact Pattern ◽  
Tooth Contact Analysis ◽  
Tooth Contact ◽  
Hypoid Gears ◽  
Practical Applications ◽  
Wheel Drive ◽  
Measuring Machine ◽  
Loaded Tooth Contact Analysis ◽  
Shape Data

Usually, the Loaded Tooth Contact Analysis (i.e. LTCA) of hypoid gears uses the nominal tooth flanks described by the machine setting and the cutter specifications. Only a few studies are performed on the LTCA directly using the measured tooth flanks such as carbonize-hardened and lapped hypoid gears. This paper presents an innovative LTCA method directly using the measured tooth flanks at each manufacturing step including not only the milling or hobbing process but also the troublesome heat-treatment, lapping or grinding processes. The proposed new LTCA method is extremely concise. Firstly, the 3-D shape data of the manufactured tooth flanks, which are the original x-y-z coordinates but not the differences against their nominal tooth flanks as before, are obtained on a coordinate-measuring machine. Another important factors the load deflections are measured on the assembled transmission by applying the static transmitting torque. Secondly, the pinion and gear are localized at the nominal mounting position, and the no load TCA can be obtained by calculating the gap between the original tooth flanks at each roll angle. Lastly, since the load deflections can be considered as the movement of mounting position, the Loaded TCA can be obtained by calculating the gap between the moved tooth flanks at new mounting position. As practical applications, the new LTCA method is used to improve the strength of high-torque hypoid gears for an All-Wheel-Drive transmission. As a result, the tooth contact pattern and pitting position observed in endurance test agreed well to the LTCA predictions and the demanding life is achieved by modifying the loaded contact pattern of lapped hypoid gears.

Experimental Investigation of Wing Accuracy Quantification using Point Cloud and Surface Deviation

2021 ◽  
Vol 4 (2) ◽  
pp. 13-20
Author(s):  
Mehmood Ahmad ◽  
Sheharyar Nasir ◽  
Zia Ur Rahman ◽  
Shuaib Salamat ◽  
Umar Sajjad ◽  
...  
Keyword(s):  
Reverse Engineering ◽  
Data Acquisition ◽  
Laser Scanning ◽  
Coordinate Measuring Machine ◽  
Surface Generation ◽  
Free Form ◽  
Cad Model ◽  
3D Cad ◽  
Deviation Analysis ◽  
Measuring Machine

A rapidly advancing lean production industry demands quick manufacturing solutions with greater precision and accuracy. This paper proposes a framework for the accurate quantification of a die-casted wing using laser scanning and reverse engineering technique. In this technique, the wing upper and lower surfaces are scanned using a Coordinate Measuring Machine (CMM). This scanned data is then imported into CAD software to generate the surface using Free Form Reverse Engineering (FFRE). The model fitness test patronizes the curve fitting used for the surface generation. The generated surface and the original 3D CAD model are investigated using deviation analysis for inaccuracies originating due to manufacturing and data acquisition. The wing is further analyzed by the point data to 3D CAD model deviation analysis. The methodology adopted significantly minimizes the data acquisition and data processing error allowing deviation to be solely traced back to the manufacturing technique.

Reverse Engineering Approach for Object with Free-Form Surfaces Using Standard Surface-Solid Parametric CAD System

2009 ◽  
Vol 147-149 ◽  
pp. 706-711 ◽  
Author(s):  
Andrzej Łukaszewicz ◽  
Kanstantsin Miatliuk
Keyword(s):  
Coordinate Measuring Machine ◽  
Free Form ◽  
Cad System ◽  
Solid Models ◽  
Middle Range ◽  
Feature Based ◽  
Measuring Machine ◽  
Cloud Of Points ◽  
Free Form Surfaces ◽  
Modelling Process

In this paper the reverse modelling process for mapping and reconstructing the geometric characteristics of element with free-form surfaces as virtual CAD model is described. The basic approach in reverse modelling process in middle range standard parametric 3D modeler such as SolidWorks system is presented. The digitizing process was performed on the coordinate measuring machine. Using surface-solid modelling tools the virtual solid models were created. They are based on prepareing 3D curves from cloud of points as a sectional profiles. As the next step, it is possible to realize various CAx applications based on 3D feature-based model. In our case an abrasive wear of rotor blade was estimated.

Measuring and Analyzing the Bevel Gears with Octoid I Teething

2013 ◽  
Vol 325-326 ◽  
pp. 870-874 ◽  
Author(s):  
Erzsebet Faluvegi ◽  
Csaba Zoltan Mate ◽  
Cătălin Ionel Cobliş ◽  
Luciana Cristea
Keyword(s):  
State Of The Art ◽  
Coordinate Measuring Machine ◽  
Error Distribution ◽  
The State ◽  
Theoretical Profile ◽  
Bevel Gears ◽  
Machine Type ◽  
Error Determination ◽  
Profile Tolerance ◽  
Measuring Machine

This paper presents the error determination on the teeths flanks of the bevel gears with straight teething using the theoretical profile. It summarizes the state-of-the-art of the profile verification. A coordinate measuring machine, type MITUTOYO Crista Plus was used for realizing the measurements. The theoretical profile is built by theoretical equations to identify the errors. The error distribution is presented by overlapping the suitable surfaces. So the bevel gears with straight teething can be evaluated in terms of the profile tolerance.

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