Touch probe radius compensation for coordinate measurement using kriging interpolation

1997 ◽  
Vol 211 (1) ◽  
pp. 11-18 ◽  
Author(s):  
J. R. R. Mayer ◽  
Y. A. Mir ◽  
F Trochu ◽  
A Vafaeesefat ◽  
M Balazinski
Keyword(s):  
Computer Aided Design ◽  
Kriging Interpolation ◽  
Free Form ◽  
Probe Radius ◽  
Part Surface ◽  
Probe Radius Compensation ◽  
Normal Vectors ◽  
Radius Compensation ◽  
Free Form Surfaces ◽  
Touch Probe

Obtaining CAD (computer aided design) descriptions of actual parts having complex surfaces is a key part of the process of reverse engineering. This paper is concerned with the estimation of actual surfaces using coordinate measuring machines fitted with a spherically tipped touch probe. In particular, it addresses in detail the problem of probe radius compensation. A general mathematical model, using kriging, is proposed which first generates the initial probe centre surface and then estimates the compensated or part surface. The compensation is achieved using normal vectors to the initial probe centre surface at each measured point to compensate for the probe radius. The method is validated experimentally on known and free-form surfaces.

An Optical-Triangulation-Based Method for Measurement of Blade Sections

2015 ◽  
Vol 713-715 ◽  
pp. 395-401
Author(s):  
Yong Zhu ◽  
Jing Liang Liu ◽  
Cheng Wei Li ◽  
Zheng Ya Kang
Keyword(s):  
High Efficiency ◽  
Optical Measurement ◽  
Measurement Methods ◽  
Free Form ◽  
Probe Radius ◽  
Optical Triangulation ◽  
Measurement Results ◽  
Probe Radius Compensation ◽  
Free Form Surface ◽  
Radius Compensation

Blades are an important part of aviation engine, its manufacturing compliance seriously affect the performance of the engine. Blades tend to be free-form surface modeling, which makes it extremely difficult to measurement. Since no probe radius compensation, high efficiency, non-contact optical measurement methods get more and more attention, but the inspection uncertainty of optical measurement is usually between 30um to 50um .To reduces the optical non-contact measurement uncertainty, this paper presents an Optical-triangulation-based method for measurement of blade sections. There is a data optimization process in the method, and this feature makes the proposed method can obtain better measurement results. At last, some experiments demonstrate the effectiveness of this method.

Reverse engineering of simple surfaces of unknown shape with touch probes: Scanning and compensation issues

2003 ◽  
Vol 217 (4) ◽  
pp. 563-568 ◽  
Author(s):  
G C Vosniakos ◽  
T Giannakakis
Keyword(s):  
Reverse Engineering ◽  
Computer Aided Design ◽  
Numerical Control ◽  
Freeform Surfaces ◽  
Cad System ◽  
Probe Radius ◽  
Computer Aided ◽  
Probe Radius Compensation ◽  
Radius Compensation ◽  
Aided Design

This work discusses issues concerning the implementation of scanning of unknown engineering objects containing just simple (i.e. no freeform) surfaces with touch probes on three-axis computer numerical control (CNC) measuring machines in order to reconstruct their shape in a computer aided design (CAD) system. Several ideas are put forward e.g. scanning along vertical slicing planes adaptive point sampling distances in-process ‘proactive’ segmentation of points into curve sections and probe radius compensation in two directions as well as limited remedy of edge scanning ambiguities. Most of the suggested algorithms are implemented as parametric numerical control (NC) programs on an OKUMA machining centre.

Automatic Generation of Anisotropic Patterns of Geometric Features for Industrial Design

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Diego Andrade ◽  
Ved Vyas ◽  
Kenji Shimada
Keyword(s):  
Boundary Conditions ◽  
Computer Aided Design ◽  
Industrial Design ◽  
Automatic Generation ◽  
Free Form ◽  
Geometric Features ◽  
Target Domain ◽  
Metric Tensor ◽  
Target Region ◽  
Free Form Surfaces

While modern computer aided design (CAD) systems currently offer tools for generating simple patterns, such as uniformly spaced rectangular or radial patterns, these tools are limited in several ways: (1) They cannot be applied to free-form geometries used in industrial design, (2) patterning of these features happens within a single working plane and is not applicable to highly curved surfaces, and (3) created features lack anisotropy and spatial variations, such as changes in the size and orientation of geometric features within a given region. In this paper, we introduce a novel approach for creating anisotropic patterns of geometric features on free-form surfaces. Complex patterns are generated automatically, such that they conform to the boundary of any specified target region. Furthermore, user input of a small number of geometric features (called “seed features”) of desired size and orientation in preferred locations could be specified within the target domain. These geometric seed features are then transformed into tensors and used as boundary conditions to generate a Riemannian metric tensor field. A form of Laplace's heat equation is used to produce the field over the target domain, subject to specified boundary conditions. The field represents the anisotropic pattern of geometric features. This procedure is implemented as an add-on for a commercial CAD package to add geometric features to a target region of a three-dimensional model using two set operations: union and subtraction. This method facilitates the creation of a complex pattern of hundreds of geometric features in less than 5 min. All the features are accessible from the CAD system, and if required, they are manipulable individually by the user.

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.

Monte Carlo simulation and analysis of free-form surface registration

1997 ◽  
Vol 211 (8) ◽  
pp. 605-617 ◽  
Author(s):  
D Brujic ◽  
M Ristic
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Confidence Intervals ◽  
Computer Aided Design ◽  
Maximum Error ◽  
Surface Registration ◽  
Performance Criteria ◽  
Free Form ◽  
Registration Method ◽  
Free Form Surfaces

Accurate dimensional inspection and error analysis of free-form surfaces requires accurate registration of the component in hand. Registration of surfaces defined as non-uniform rational B-splines (NURBS) has been realized through an implementation of the iterative closest point method (ICP). The paper presents performance analysis of the ICP registration method using Monte Carlo simulation. A large number of simulations were performed on an example of a precision engineering component, an aero-engine turbine blade, which was judged to possess a useful combination of geometric characteristics such that the results of the analysis had generic significance. Data sets were obtained through CAD (computer aided design)-based inspection. Confidence intervals for estimated transformation parameters, maximum error between a measured point and the nominal surface (which is extremely important for inspection) mean error and several other performance criteria are presented. The influence of shape, number of measured points, measurement noise and some less obvious, but not less important, factors affecting confidence intervals are identified through statistical analysis.

Computer Aided Style Design System Based on Highlight Lines

2009 ◽  
Author(s):  
Sakiko Yano ◽  
Hideki Aoyama
Keyword(s):  
Surface Shape ◽  
Free Form ◽  
Design System ◽  
Normal Vector ◽  
High Quality ◽  
Design Work ◽  
Design Processes ◽  
Normal Vectors ◽  
Free Form Surfaces ◽  
Unit Normal

Free-form surfaces are useful for modeling the external shape of industrial products but designers are still facing difficulty in designing high-quality aesthetic surfaces because commercial CAD systems currently available lack the required performance to support their design work. This has therefore led to the increasing need for design-aiding modeling systems to enhance the efficiency of high quality surface design processes. This paper proposes a method of redesigning aesthetic surface shapes by controlling unit normal vectors on the surface and discusses a fundamental system constructed based on the proposed technique. Attempts were also made to construct the required character lines using the proposed technique. Additionally, the validity of the proposed technique was also verified. In the surface evaluation stage of existing product design processes, the highlight-check method using highlight lines on the surface of a model is the most common and popular evaluation method even though methods using curvature and isophote have been proposed. With this method, the unit normal vectors on the surface are controlled by highlight lines. A highlight line is defined as a curve which consists of points with a constant angle to the right reflective direction when a beam shines on an arbitrary point on a surface. With this highlight-check system, highlight lines are displayed on the screen and evaluated by the designer. When highlight lines are faulty or those required by the designer cannot be obtained, the designer just needs to enter the required highlight lines manually by drawing with a pen tablet on LCD interactive display to improve surface quality. Usually, the system takes input highlight line information as unit normal vector information, and constructs the required surface shape using that information.

Efficient Tool-Path Planning for Machining Free-Form Surfaces

1996 ◽  
Vol 118 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Rong-Shine Lin ◽  
Y. Koren
Keyword(s):  
Path Planning ◽  
Tool Path ◽  
Free Form ◽  
Tool Path Planning ◽  
Efficient Tool ◽  
New Approach ◽  
Milling Machines ◽  
Part Surface ◽  
Tool Path Interval ◽  
Free Form Surfaces

This paper presents an analytical method for planning an efficient tool-path in machining free-form surfaces on 3-axis milling machines. This new approach uses a nonconstant offset of the previous tool-path, which guarantees the cutter moving in an unmachined area of the part surface and without redundant machining. The method comprises three steps: (1) the calculation of the tool-path interval, (2) the conversion from the path interval to the parametric interval, and (3) the synthesis of efficient tool-path planning.

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