Study on automated non-contact measurement of 3-D edge profile for free form surface model

2000 ◽  
Vol 2000.3 (0) ◽  
pp. 541-542
Author(s):  
Yasuhiro TAKAYA ◽  
Seojoon LEE ◽  
Satoru TAKAHASHI ◽  
Takashi MIYOSHI
Keyword(s):  
Free Form ◽  
Surface Model ◽  
Contact Measurement ◽  
Edge Profile ◽  
Free Form Surface

Creation and Manipulation of Complex Displacement Features During the Conceptual Phase of Design

1996 ◽  
Author(s):  
P. A. van Elsas ◽  
J. S. M. Vergeest
Keyword(s):  
Boundary Conditions ◽  
Surface Feature ◽  
Free Form ◽  
Shape Design ◽  
Surface Model ◽  
Test Results ◽  
Base Surface ◽  
Feature Design ◽  
Data Explosion ◽  
Free Form Surface

Abstract Surface feature design is not well supported by contemporary free form surface modelers. For one type of surface feature, the displacement feature, it is shown that intuitive controls can be defined for its design. A method is described that, given a surface model, allows a designer to create and manipulate displacement features. The method uses numerically stable calculations, and feedback can be obtained within tenths of a second, allowing the designer to employ the different controls with unprecedented flexibility. The algorithm does not use refinement techniques, that generally lead to data explosion. The transition geometry, connecting a base surface to a displaced region, is found explicitly. Cross-boundary smoothness is dealt with automatically, leaving the designer to concentrate on the design, instead of having to deal with mathematical boundary conditions. Early test results indicate that interactive support is possible, thus making this a useful tool for conceptual shape design.

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.

Multiple-Points Constraints Based Deformation for Free-Form Surfaces

1999 ◽  
Author(s):  
J. M. Zheng ◽  
K. W. Chan ◽  
I. Gibson
Keyword(s):  
Surface Deformation ◽  
Single Point ◽  
Displacement Function ◽  
Surface Shape ◽  
Free Form ◽  
Surface Model ◽  
Deformation Method ◽  
Multiple Points ◽  
Free Form Surface ◽  
Free Form Surfaces

Abstract There is an increasing demand in the conceptual design for more intuitive methods for creating and modifying free-form curves and surfaces in CAD modeling systems. The methods should be based not only on the change of the mathematical parameters but also on the user’s specified constraints and shapes. This paper presents a new surface representation model for free-form surface deformation representation. The model is a combination of two functions: a displacement function and a function for representing an existing NURBS surface called parent surface. Based on the surface model, the authors develop two deformation methods which are named SingleDef (Single-point constraint based deformation method), and MultiDef (Multiple-points constraints based deformation method). The techniques for free-form surface deformation allow conceptual designer to modify a parent surface by directly applying point constraints to the parent surface. The deformation methods are implemented and taken in an experimental CAD system. The results show that the designer can easily and intuitively control the surface shape.

scholarly journals Reverse Engineering of Free-Form Surface Based on the Closed-Loop Theory

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Xue Ming He ◽  
Jun Fei He ◽  
Mei Ping Wu ◽  
Rong Zhang ◽  
Xiao Gang Ji
Keyword(s):  
Reverse Engineering ◽  
Point Cloud ◽  
Closed Loop ◽  
Free Form ◽  
Surface Model ◽  
Accurate Model ◽  
Check Points ◽  
Adaptive Measurement ◽  
Free Form Surface ◽  
Free Form Surfaces

To seek better methods of measurement and more accurate model of reconstruction in the field of reverse engineering has been the focus of researchers. Based on this, a new method of adaptive measurement, real-time reconstruction, and online evaluation of free-form surface was presented in this paper. The coordinates and vectors of the prediction points are calculated according to a Bézier curve which is fitted by measured points. Final measured point cloud distribution is in agreement with the geometric characteristics of the free-form surfaces. Fitting the point cloud to a surface model by the nonuniform B-spline method, extracting some check points from the surface models based on grids and a feature on the surface, review the location of these check points on the surface with CMM and evaluate the model, and then update the surface model to meet the accuracy. Integrated measurement, reconstruction, and evaluation, with the closed-loop reverse process, established an accurate model. The results of example show that the measuring points are distributed over the surface according to curvature, and the reconstruction model can be completely expressed with micron level. Meanwhile, measurement, reconstruction and evaluation are integrated in forms of closed-loop reverse system.

Free Form Surface Reconstruction Method Based on LS-SVM

2011 ◽  
Vol 308-310 ◽  
pp. 280-283
Author(s):  
Fu Zhong Wu
Keyword(s):  
Surface Reconstruction ◽  
Approximation Error ◽  
Engineering Application ◽  
Least Square ◽  
Free Form ◽  
Support Vector ◽  
Surface Model ◽  
Reconstruction Method ◽  
Svm Model ◽  
Free Form Surface

A free form surface reconstruction method based on least square support vector regression is presented. Firstly in order to eliminate noise points, some sample points are chosen from the measured data to construct LS-SVM model. Thus a LS-SVM model to approximate the measured points is obtained. And the distribution probability of the approximation error is figured out. In result, the noise points are eliminated when their error probability is less than the specified threshold value. Then the boundary points are extracted. Lastly the surface model is reconstructed by use of the measured points from which noise points have been eliminated. The results indicate that the reconstruction precision can satisfy the demands of engineering application.

Experimental Assessment for Examination of Curves and Surfaces by Auditory Sense

1997 ◽  
Vol 9 (6) ◽  
pp. 434-438
Author(s):  
Hidetomo Takahashi ◽  
◽  
Satoshi Kanai ◽  
Keyword(s):  
Acoustic Waves ◽  
Experimental System ◽  
Free Form ◽  
Surface Model ◽  
Geometric Information ◽  
Experimental Assessment ◽  
Curves And Surfaces ◽  
Surface Models ◽  
Auditory Sense ◽  
Free Form Surface

The purpose of this research is to assess the ability of the auditory sense to examine curves and free-form surface models in order to verify their appearances. In this paper, the authors will first show how to display a curve and a surface model using an acoustic wave, i.e., the information about curves and surfaces that is needed, the kinds of acoustic waves that should be displayed, and how to relate the geometric information from curves or surfaces to the acoustic waves that are to be displayed. Next, the authors will discuss their newly developed experimental system. Finally, the ability of the auditory sense to examine curves and surfaces will be assessed experimentally. It will be demonstrated that the auditory sense can examine curves and surfaces.

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