scholarly journals The design of the sampling parameters for CMM of free-form surfaces

2022 ◽  
Vol 355 ◽  
pp. 03066
Author(s):  
Yikun Zhang ◽  
Yueping Chen ◽  
Kaiqi Huang
Keyword(s):  
Random Sampling ◽  
Measurement Accuracy ◽  
Free Form ◽  
Actual Contour ◽  
Ball Diameter ◽  
Grid Block ◽  
Block Area ◽  
Minimum Block ◽  
Free Form Surface ◽  
Free Form Surfaces

In order to improve the inspection accuracy of free-form surface by CMM, this paper adopted the different sampling parameters to research the influence of the measurement accuracy of free-form surface. Through the combination of area uniform block random sampling and Latin hypercube random sampling, the minimum sampling grid block area and ball diameter were taken as the research parameters. Firstly, this research analysed theoretically the influence of measurement accuracy of free-form surface by different sampling parameters. Secondly, carrying out experiments verified the analytical results. Then, the influence of two groups of sampling parameters on the normal deviation of free-form surface could be acquired by analysing the experimental data. Finally, this research could obtain the result of normal deviation of free-form surface. The research results showed that the minimum block area of sampling and the diameter of measuring ball become smaller, and the profile error become larger when the number of measuring points were the same, the more it can reflect the actual contour of the free-form surface, which proves that the measurement accuracy is higher.

Application of Convex Hull for Tool Interference Avoidance in 5-Axis CNC Machining

1996 ◽  
Author(s):  
Yuan-Shin Lee ◽  
Tien-Chien Chang
Keyword(s):  
Convex Hull ◽  
Tool Path ◽  
Correction Method ◽  
Nc Machining ◽  
Cnc Machining ◽  
Free Form ◽  
Interference Avoidance ◽  
Tool Interference ◽  
Free Form Surface ◽  
Free Form Surfaces

Abstract In this paper, a methodology of applying convex hull property in solving the tool interference problem is presented for 5-axis NC machining of free-form surfaces. Instead of exhausted point-by-point checking for possible tool interference, a quick checking can be done by using the convex hull constructed from the control polygon of free-form surface modeling. Global tool interference in 5-axis NC machining is detected using the convex hull of the free-form surface. A correction method for removing tool interference has also been developed to generate correct tool path for 5-axis NC machining. The inter-surface tool interference can be avoided by using the developed technique.

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.

Algorithmen-basierte Freiformflächenstrukturierung/Generation of NC programs for the micromilling structuring of free-form surfaces – Algorithm-based free-form surface structuring

2021 ◽  
Vol 111 (11-12) ◽  
pp. 797-802
Author(s):  
Leonhard Alexander Meijer ◽  
Torben Merhofe ◽  
Timo Platt ◽  
Dirk Biermann
Keyword(s):  
Computer Aided Design ◽  
Computational Effort ◽  
Free Form ◽  
Process Chain ◽  
Surface Structuring ◽  
Computer Aided ◽  
Cad Cam ◽  
Free Form Surface ◽  
Aided Design ◽  
Free Form Surfaces

In diesem Beitrag wird ein neuer Ansatz zum Erstellen von Maschinenprogrammen zur mikrofrästechnischen Oberflächenstrukturierung vorgestellt und die Anwendung der Prozesskette für ein komplexes, industrielles Verzahnungswerkzeug beschrieben. Durch die Reduzierung des Berechnungsaufwandes in der CAD/CAM (Computer-aided Design & Manufacturing)-Umgebung können die Limitierungen konventioneller Softwarelösungen umgangen und Bearbeitungsprogramme für komplexe Strukturierungsaufgaben effizient erstellt werden.   A new method for generating machine programs for micromilling surface structuring is presented, and the application of the process chain to a complex, industrial gearing die is described. By reducing the computational effort in the CAD/CAM (Computer-aided Design & Manufacturing) environment, the problems of conventional software solutions can be avoided and complex machining programs can be created.

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 Measurement point sampling method for inspection of parts with free-form surfaces

2018 ◽  
Vol 10 (11) ◽  
pp. 168781401880957 ◽  
Author(s):  
Dezhong Zhao ◽  
Wenhu Wang ◽  
Jinhua Zhou ◽  
Ruisong Jiang ◽  
Kang Cui ◽  
...  
Keyword(s):  
Measurement Accuracy ◽  
Sampling Method ◽  
Free Form ◽  
Surface Inspection ◽  
B Spline ◽  
Spline Curves ◽  
Data Points ◽  
Manufacturing Accuracy ◽  
Method Of Measurement ◽  
Free Form Surfaces

Parts must be measured to evaluate the manufacturing accuracy in order to check whether their dimension is in expected tolerance. In engineering, parts with free-form surfaces are generally measured by high-precision coordinate-measuring machines. The measurement accuracy is usually improved by increasing the density of measurement points, which is time-consuming and costly. In this article, a novel sampling method of measurement points for free-form surface inspection is proposed. First, surface inspection is simplified into the inspection of a number of section curves of the surface. Second, B-spline curves constructed with an iterative method are employed to approximate these section curves. Subsequently, data points necessary to construct the B-spline curves are taken as the measurement points. Finally, the proposed method is compared with other two sampling methods. The results indicate that the proposed method greatly reduced the number of measurement points without decreasing the precision of surface modeling.

A Shape Modeling System with a Volume Scanning Display and Multisensory Input Device

1993 ◽  
Vol 2 (2) ◽  
pp. 104-111 ◽  
Author(s):  
Ken-ichi Kameyama ◽  
Koichi Ohtomi
Keyword(s):  
Virtual Reality ◽  
Shape Modeling ◽  
Free Form ◽  
Input Device ◽  
Surface Image ◽  
Free Form Surface ◽  
Multisensory Input ◽  
Free Form Surfaces ◽  
As If

This paper describes a newly developed 3-D shape modeling system, in which a user can design a free-form surface as if he or she actually manipulates a flexible object made from rubber or clay. Such reality can be realized in the system without any encumbering devices like goggles, glasses, or gloves, which is impossible in conventional virtual reality systems. The system is composed of a volume scanning display for presenting a surface image in a real 3-D space, a multisensory input device for detecting the force for deformation, and a half-silvered mirror for spatial superposition of the image onto the input device. A user can directly manipulate a free-form surface by virtually pushing the image, actually pushing the input device, and at the same time, he or she can feel the input device resist its actual deformation as the resisting force of the virtual surface. The system has several types of deforming models, and two types of free-form surfaces that have different curvatures have been experimentally created.

A Generic Approach to Free Form Surface Generation

2002 ◽  
Vol 2 (4) ◽  
pp. 294-301 ◽  
Author(s):  
J. Cotrina-Navau ◽  
N. Pla-Garcia ◽  
M. Vigo-Anglada
Keyword(s):  
Theoretical Approach ◽  
Differentiable Manifold ◽  
Surface Generation ◽  
Free Form ◽  
B Spline ◽  
Free Form Surface ◽  
Manifold Theory ◽  
Free Form Surfaces

A theoretical approach to construct free form surfaces is presented. We develop the concepts that arise when a free form surface is generated by tracing a mesh, using differentiable manifold theory, and generalizing the B-spline scheme. This approach allows us to define a family of practical schemes. Four different applications of the generic approach are also presented in this paper.

Tool Path Generation Method for High-Quality Machining of Free-Form Surfaces

2020 ◽  
Author(s):  
Yuki Takanashi ◽  
Hideki Aoyama
Keyword(s):  
Tool Path ◽  
High Accuracy ◽  
Tool Path Generation ◽  
Free Form ◽  
Machining Accuracy ◽  
Path Generation ◽  
High Quality ◽  
Nc Program ◽  
Free Form Surface ◽  
Free Form Surfaces

Abstract Machining data (NC program) is generated by a CAM system, which generates the tool path from the target shape as a plane approximation surface instead of a free-form surface. Owing to this plane approximation, machining accuracy is reduced. In this paper, we propose a method to process the shape with high accuracy by defining the areas where accuracy is not required as a plane approximation surface and defining the part where accuracy is required as free-form surfaces.

Effect of the Working Diameter to the Surface Quality in Free-Form Surface Milling

2013 ◽  
Vol 581 ◽  
pp. 372-377 ◽  
Author(s):  
Balázs Mikó ◽  
Jozef Beňo
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Cutting Speed ◽  
Chip Thickness ◽  
Free Form ◽  
Effective Diameter ◽  
Test Part ◽  
Free Form Surface ◽  
Free Form Surfaces

The article presents the changing of the working diameter (effective diameter) and its effect to the surface roughness based on milling experiments of a test part in 3D milling of free-form surfaces. The position of the surface and the step depth determine the effective diameter, in case of constant revolution of the tool, the actual cutting speed and the minimal removable chip thickness will change. The article presents the result of the application of the constant cutting speed and feed per tooth.

Theoretical Research on Polishing Free-Form Surface with Magnetic Abrasive Finishing

2008 ◽  
Vol 392-394 ◽  
pp. 404-408 ◽  
Author(s):  
Man Dong Zhang ◽  
Ming Lv ◽  
H.L. Chen
Keyword(s):  
Design Theory ◽  
Theoretical Research ◽  
Free Form ◽  
Machining Accuracy ◽  
Magnetic Pole ◽  
Computer Aided Geometric Design ◽  
Magnetic Abrasive Finishing ◽  
Abrasive Finishing ◽  
Free Form Surface ◽  
Free Form Surfaces

In the paper, polishing free-form surfaces of die are studied with magnetic abrasive finishing. The principle of magnetic abrasive finishing free-form surface, the design of magnetic pole, the composition and categories of magnetic abrasive are introduced. Through digitizing of free-form surface by using trimmed NURBS, based on residual roughness, machining accuracy and other parameters, the offset variable of free-form surface, which is the path of magnetic pole, is derived with the computer aided geometric design theory. These will provide theoretic foundation for the realization of finishing free-form surfaces of die automatically.

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