Research and Development of a CAD/CAM System for Free-Form Surfaces by Using NURBS

2002 ◽  
Vol 2002.12 (0) ◽  
pp. 99-102
Author(s):  
Masaaki WATANABE ◽  
San de GAO
Keyword(s):  
Research And Development ◽  
Free Form ◽  
Cad Cam ◽  
Free Form Surfaces

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.

Automated Tool-Orientation Determinations for 4-Axis Non-Gouge, Non-Interference Milling of Axial-Flow Compressors Airfoils

2007 ◽  
Author(s):  
Zezhong C. Chen ◽  
Gang Liu
Keyword(s):  
Manufacturing Industry ◽  
Axial Flow ◽  
Optimization Method ◽  
Free Form ◽  
Software Systems ◽  
Cnc Milling ◽  
Novel Approach ◽  
Cad Cam ◽  
Free Form Surfaces ◽  
Axial Flow Compressors

As important components of gas turbine engines, axial-flow compressors have been improved with a more complex and accurate airfoil design to meet high aerodynamic requirements; specifically, the pressure and suction surfaces of the airfoils (or blades) are now represented with free-form surfaces in CAD software systems. Since quality of the blades affects efficiency of the engines and safety of the aircrafts, some types of compressors are produced with the blades and the hub as a single piece on 4-axis CNC milling machines. However, it is still quite challenging to automatically determine cutter sizes and orientations without gouging and interference during the 4-axis milling, because the geometric shape of the blades is complex and the blades overlap with each other. As a result, the established method of determining tool size and orientation in industry is by trial and error in a repetitive process of selecting cutters and planning tool-paths with CAM systems. To address this problem, a novel approach is proposed to automatically determine cutter sizes and orientations for 4-axis milling of the axial-flow compressors blades without gouging and interference. The main contribution of this work is that (1) a mathematical model for optimizing cutter sizes in 4-axis milling is established; and (2) by applying a global optimization method — the particle swarm optimization method — to this model, the maximum allowable size of a cutter and its corresponding orientation can be found at each cutter-contact (CC) point on the surface being machined. Therefore, all the maximum allowable sizes of cutters for all the CC points and the corresponding cutter orientations can be computed. A group of standard cutters are then selected; each of which can sweep particular CC points without damaging the compressor. Since it is efficient and reliable, this newly proposed approach can be directly implemented in commercial CAD/CAM software systems to benefit the manufacturing industry.

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.

Tool Path Generation for Free Form Surfaces in Robot-Based Incremental Sheet Metal Forming

2009 ◽  
Vol 410-411 ◽  
pp. 143-150 ◽  
Author(s):  
Horst Meier ◽  
Jan Brüninghaus ◽  
B. Buff ◽  
Alfred Hypki ◽  
Adrian Schyja ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Industrial Robots ◽  
Sensor Data ◽  
Free Form ◽  
Work Piece ◽  
Tool Paths ◽  
Cad Cam ◽  
Free Form Surfaces

This paper describes a new development in incremental, robot-based sheet metal forming (Roboforming). Roboforming is a dieless sheet metal forming process which ensures cost-effective manufacturing of prototype parts and small batches. Its principle is based on flexible shaping by means of a freely programmable path synchronous movement of two industrial robots driving work-piece independent forming tools. The final shape is produced by the incremental inward motion of the forming tool in depth direction and its movement along the contour in lateral direction on a heli-cal path. The supporting tool, with its simple geometry, holds the sheet on the backside by moving syn¬chronously along the outer contour, at constant depth. In this way no special dies are needed. For mil¬ling machines, which are used in numerous incremental forming approaches, CAD/CAM inter¬faces exist for generating necessary tool paths. For industrial robots only a few simple solutions emerge, which do not have the potential of classical CAD/CAM interfaces and are unusable for co-operating robot systems. While the two coupled robot programs can be programmed manually for simple geometries, this approach does not work for complex geometries. In this paper a further de-velopment in robot programming systems is presented that is now able to derive helical tool paths from any CAD file and generate two cooperating programs for the forming and the sup¬porting tools. The helixes pitch is variable and dependent on the geometry’s wall angle. To increase the part accu¬racy a process database is used, that stores relevant information about the process pa¬rameters, sensor data and used equipment. Based on this information strategies for increasing the part accuracy can be applied.

Research on the Automatic Programming System for Industrial Robots in Free-Form Surfaces Polishing

2010 ◽  
Vol 455 ◽  
pp. 181-185 ◽  
Author(s):  
Jian Ming Zhan ◽  
Q.T. Liu ◽  
Gang Ming Wang
Keyword(s):  
Industrial Robots ◽  
Degree Of Freedom ◽  
Free Form ◽  
Programming System ◽  
Automatic Programming ◽  
Nc Code ◽  
Cad Cam ◽  
Programming Software ◽  
Free Form Surfaces ◽  
Cam Software

Because of the industrial robot’s advantages and characteristics of degree of freedom, it is broadly applied in mold and die of curved surfaces polishing. But its excessive degree of freedom also brings great difficulties in programming for there is CAD/CAM software can do it well. By analyzing the ISO NC code and robot’s programming criterion, this paper develops off-line programming software for industrial robots in free-form surfaces polishing.

Extension of Vectorial Tolerances for Coordinate Measurement Analysis

1997 ◽  
Author(s):  
Hong-Tzong Yau
Keyword(s):  
Systematic Evaluation ◽  
Free Form ◽  
Mathematical Basis ◽  
Evaluation Approach ◽  
Measurement Analysis ◽  
Manufacturing Process Control ◽  
Cad Cam ◽  
Orientation Vector ◽  
Geometric Elements ◽  
Free Form Surfaces

In recent years, vectorial tolerancing has emerged as a new alternative of representing workpiece tolerances. In contrast with conventional geometric tolerances that originated from hard gauging practice, vectorial tolerancing follows the working principle of coordinate measuring machines and CAD/CAM systems. Moreover it provides feedback from measurement directly to manufacturing process control. Many believe it is a better tolerancing method to tie design, manufacturing, and measurement together. However, current proposal of vectorial tolerancing has several limitations. First, the current orientation vector is inadequate for representing true 3D orientation. As a result, the orientation of a free form surface can not be properly established. Second, there has not been much discussion on the subject of vectorial tolerance evaluation. This paper proposes a new orientation vector which provides a more general mathematical basis for representing vectorial tolerances. It enables true 3D orientation representation and relates tolerances to functional requirement. With the mathematical definition, a systematic evaluation approach becomes possible for both analytical geometric elements and free form surfaces. Computer simulation and real-world application were studied to validate this new approach.

Visual assessment of free-form surfaces in CAD/CAM

1998 ◽  
Vol 212 (3) ◽  
pp. 207-214 ◽  
Author(s):  
R J Cripps ◽  
A A Ball
Keyword(s):  
Computer Aided Design ◽  
Mathematical Theory ◽  
Visual Assessment ◽  
Free Form ◽  
Design Engineers ◽  
Surface Models ◽  
Cad Cam ◽  
Aided Design ◽  
Free Form Surfaces

This paper reviews the current graphical tools available for checking the quality of CAD/CAM (computer aided design/manufacture) surface models and highlights the difficulties of their use. A new range of geometrically based tools is proposed, especially designed for the task of enabling design engineers to visually assess the quality of free-form surfaces at a workstation screen to within an accuracy comparable with working to full-scale drawings. The tools should be easy to use without recourse to understanding the underlying mathematical theory of surface differential geometry on which the techniques are ultimately based.

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