FREE-FORM SURFACE PARTITION IN 3-D

2011 ◽  
Vol 21 (06) ◽  
pp. 609-634 ◽  
Author(s):  
DANNY Z. CHEN ◽  
EWA MISIOŁEK
Keyword(s):  
Time Algorithm ◽  
Point Of View ◽  
Free Form ◽  
Convex Polygons ◽  
Geometric Problem ◽  
Surface Machining ◽  
Insertions And Deletions ◽  
Surface Partitioning ◽  
Free Form Surface ◽  
Free Form Surfaces

We present a theoretical study of a problem related to optimal free-form surface partitioning, which arises in surface machining in manufacturing. In particular, we consider partitioning a free-form surface in 3-D into two subsurfaces subject to a global objective function. As a key subroutine, we develop new algorithms for the geometric problem of processing an off-line sequence of insertions and deletions of convex polygons alternated with point membership/proximity queries on the common intersection of the polygons. We show how this subroutine can be used to solve surface 2-partitioning. Our algorithm for the 2-partitioning problem takes [Formula: see text] time, where m is the number of polygons of size O(n) each. This improves the asymptotic time complexity of the previous best-known O(m2n2)-time algorithm. Our algorithms may be applicable to other accessibility and partition problems involving free-form surfaces in computer graphics and manufacturing. From the computational geometry point of view, our method combines nontrivial data structures, geometric observations, and algorithmic techniques that may be used to solve other geometric problems. For example, our algorithm can process O(n) insertions and deletions of convex polygons (of size O(n) each) and queries on their intersections in O(n2 log log n) time, improving the "standard" O(n2 log n) time solution.

scholarly journals Improving the accuracy of free-form surface machining on CNC milling machines

Mechanik ◽  
2018 ◽  
Vol 91 (12) ◽  
pp. 1100-1103
Author(s):  
Andrzej Werner
Keyword(s):  
Geometric Model ◽  
Free Form ◽  
Cnc Milling ◽  
Surface Machining ◽  
Machining Errors ◽  
Milling Machines ◽  
Coordinate Measurements ◽  
Free Form Surface ◽  
Free Form Surfaces

This article presents a method of increasing the accuracy of the production of free-form surfaces. This method is based on the execution of coordinate measurements of the pre-treated object and reconstruction of its nominal geometric model in order to compensate existing machining errors.

Model Based Feedrate Scheduling for Free-Form Surface Machining

2010 ◽  
Vol 4 (3) ◽  
pp. 273-283 ◽  
Author(s):  
Yaman Boz ◽  
◽  
Onur Demir ◽  
Ismail Lazoglu
Keyword(s):  
Threshold Value ◽  
Free Form ◽  
Machining Processes ◽  
Surface Machining ◽  
Scheduling Strategy ◽  
Model Based ◽  
Feedrate Scheduling ◽  
Deflection Analysis ◽  
Free Form Surface ◽  
Free Form Surfaces

Free-form surfaces are commonly used in the automotive, aerospace, biomedical, home appliance, and die/mold industries. Minimizing cycle times is crucial for free-form surface machining in today’s competitive market. Although there have been remarkable enhancements in the CAD/CAM industry, these enhancements lack physical insight into machining processes. This article presents a model-based feedrate scheduling strategy for 3-axis machining of free-form surfaces. In feedrate scheduling strategy, cycle time is minimized by off-line control of cutting forces under a threshold value between specified feedrate values. Using tool deflection analysis, surface form error can also be predicted. The proposed approaches are tested under various machining conditions and the results are presented in the paper.

scholarly journals Optimization of free-form surface machining using parallel planes strategy and torus milling cutter

2016 ◽  
Vol 232 (2) ◽  
pp. 240-250 ◽  
Author(s):  
Jean-Max Redonnet ◽  
Alejandro Gamboa Vázquez ◽  
Alberto Traslosheros Michel ◽  
Stéphane Segonds
Keyword(s):  
End Milling ◽  
Free Form ◽  
End Mill ◽  
Machining Time ◽  
Surface Machining ◽  
End Mills ◽  
Free Form Surface ◽  
Optimization Methodology ◽  
Free Form Surfaces ◽  
Industrial Part

Machining by parallel planes is a widely used strategy for end-milling of free-form surfaces on 3-axis numerically controlled machines. In industry, this type of machining is generally performed with a hemispherical tool. However, numerous studies have shown the benefits of torus-end mills over ball-end or flat-end mills. More than anything, the machining direction has much influence on productivity while using a torus-end mill. In this context, the choice of the machining direction is of paramount importance when using a torus-end mill in the machining of free-form surfaces. This paper presents an optimization of part machining direction allowing the machining time to be minimized while respecting the maximum imposed scallop height. This optimization methodology is then applied to an industrial part and measurements are performed on this part. The study highlights the interest of optimizing the machining direction and the benefits that can be drawn with respect to machining using a non-optimized direction.

Tool Path Generation for Five-Axis Controlled Machining of Free-Form Surface Using Barrel Tool: Control of Contact Point on Cutting Edge

2020 ◽  
Author(s):  
Tomonobu Suzuki ◽  
Koichi Morishige
Keyword(s):  
Tool Path ◽  
Contact Point ◽  
Cutting Edge ◽  
Free Form ◽  
End Mill ◽  
Ball End Mill ◽  
Surface Machining ◽  
Free Form Surface ◽  
The Cost ◽  
Five Axis

Abstract This study aimed to improve the efficiency of free-form surface machining by using a five-axis controlled machine tool and a barrel tool. The barrel tool has cutting edges, with curvature smaller than the radius, increasing the pick feed width compared with a conventional ball end mill of the same tool radius. As a result, the machining efficiency can be improved; however, the cost of the barrel tool is high and difficult to reground. In this study, a method to obtain the cutting points that make the cusp height below the target value is proposed. Moreover, a method to improve the tool life by continuously and uniformly changing the contact point on the cutting edge is proposed. The usefulness of the developed method is confirmed through machining simulations.

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.

Machining of Carbon Fibre-Reinforced Silicon-Ccarbide Composites

2008 ◽  
Vol 59 ◽  
pp. 51-54 ◽  
Author(s):  
Dirk Biermann ◽  
T. Jansen ◽  
M. Feldhoff
Keyword(s):  
Silicon Carbide ◽  
Carbon Fibre ◽  
Drill Hole ◽  
Free Form ◽  
Surface Machining ◽  
Free Form Surface ◽  
Hole Machining

A growing demand for fibre-reinforced ceramics necessitates effective ways for machining these materials. In this paper, different tool concepts are presented for an efficient machining of carbon fibre-reinforced silicon carbide. Drill hole machining, slot machining and first investigations of free-form surface machining are presented.

scholarly journals A High-Efficiency Impeller Channel Quasi-Triangular Tool Path Planning Method Based on Template Trajectory Mapping

2018 ◽  
Vol 36 (6) ◽  
pp. 1216-1223
Author(s):  
Feiyan Han ◽  
Juan Wei ◽  
Bin Feng ◽  
Wu Zhang
Keyword(s):  
Path Planning ◽  
Tool Path ◽  
Planning Method ◽  
Free Form ◽  
Physical Domain ◽  
Tool Path Planning ◽  
Surface Machining ◽  
Mapping Model ◽  
Trajectory Mapping ◽  
Free Form Surface

The manufacturing technology of an integral impeller is an important indicator for measuring the manufacturing capability of a country. Its manufacturing process involves complex free-form surface machining, a time consuming and error-prone process, and the tool path planning is considered as a critical issue of free-form surface machining but still lacks a systematic solution. In this paper, aiming at the tool path planning of the impeller channel, a quasi-triangular tool path planning method based on parametric domain template trajectory mapping is proposed. The main idea is to map the template trajectory to physical domain by using the mapping model of parametric domain to the physical domain to obtain the actual machining path. Firstly, the trajectory mapping model of parametric domain to physical domain is established using the morphing technique, and the template trajectory mapping method in the parametric domain is given. Secondly, the clean-up boundary of the impeller channel is determined in the parametric domain, and the quasi-triangular template trajectory of the impeller channel is defined. Finally, taking a certain type of impeller as an example, the quasi-triangular tool path of the impeller channel is calculated, and the tool path calculation time of this method is compared with that of the traditional isometric offset method. The result shows that the computational efficiency is improved by 45% with this method, which provides a new method for the rapid acquisition of NC machining tool path for impeller channels. In addition, the simulation and actual machining are carried out, the results show that the shape of actual cutting traces on the surface of the impeller channel is quasi-triangular, showing that this method is effective and feasible.

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.

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