Global Tangent Visibility Analysis for Polyhedral Computer Aided Design Models

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Zhi Yang ◽  
Richard A. Wysk ◽  
Sanjay Joshi
Keyword(s):  
Computer Aided Design ◽  
Coordinate Measuring Machine ◽  
Casting Process ◽  
Hot Wire ◽  
Visibility Analysis ◽  
Design Models ◽  
Visibility Algorithm ◽  
New Type ◽  
Measuring Machine ◽  
Aided Design

Visibility analysis is broadly used in milling and casting process planning and in coordinate measuring machine applications. However, standard visibility analysis (which involves determining visibility from a given viewpoint), cannot be applied directly to in-line cutting systems such as wire electrical discharge machines or hot wire foam cutters. The motivation of this paper is to accurately calculate the tangent visibility for objects represented by polygonal surfaces. In this paper we define a new type of visibility - tangent visibility. We develop an algorithm to calculate the global tangent visibility for in-line cutting systems, and several models are tested to verify its accuracy. Several polyhedral models are tested to verify the correctness of the tangent visibility algorithm; and the complexity of the algorithm is also discussed.

Automatic Coordinate Measuring Machine Inspection

1999 ◽  
Author(s):  
V. A. Albuquerque ◽  
F. W. Liou ◽  
S. Agarwal ◽  
O. R. Mitchell
Keyword(s):  
Path Planning ◽  
Computer Aided Design ◽  
Coordinate Measuring Machine ◽  
Industrial Applications ◽  
Prototype Development ◽  
Development Cycle ◽  
Inspection Process ◽  
Measuring Machine ◽  
Aided Design ◽  
Point Placement

Abstract In many industrial applications, such as product prototype development, automation of inspection process can greatly improve product quality and product development cycle, time. This paper discusses a development of a vision aided automatic inspection using Coordinate Measuring Machine (CMM). We seek to integrate the flexibility afforded by computer vision systems with the precision of numerically controlled coordinate measuring machines to achieve a fully automatic and reliable inspection of the industrial parts. The 3-D design information and part specification from computer-aided design file is used for inspection point placement and CMM path planning. The proposed system demonstrates that optimal collision-free inspection paths can be efficiently generated for geometrically complex parts consisting of multiply intersecting features. This is made possible by using iterative subdivision of surfaces for point placement coupled with, efficient 3-D collision avoidance and path planning. The paper discusses different algorithms used, and presents experimental results.

The Use of a Machine Vision System in a Flexible Manufacturing Cell Incorporating an Automated Coordinate Measuring Machine

1993 ◽  
Vol 207 (3) ◽  
pp. 199-204 ◽  
Author(s):  
X J Wang ◽  
C Butler
Keyword(s):  
Machine Vision ◽  
Flexible Manufacturing ◽  
Computer Aided Design ◽  
Manufacturing System ◽  
Vision System ◽  
Coordinate Measuring Machine ◽  
Cad System ◽  
Measuring Machine ◽  
Processing Techniques ◽  
Aided Design

The aim of this paper is to present a practical approach to the solution of problems associated with using an automated coordinate measuring machine (CMM) in a flexible manufacturing system (FMS) environment. The approach described uses machine vision and image processing techniques to permit transformations of the coordinate systems. In order to achieve flexible inspection, the system can recognize different workpieces by a quick matching method. The actual measuring path for the workpiece is derived from the original measuring path templates to allow for a workpiece to be measured in an arbitrary orientation on the table of the CMM. The original measuring path can be generated off-line by self-teach programming or from a computer aided design (CAD) system. The generation of the actual measuring path of the CMM is not limited by the complexity of the original off-line measuring path.

scholarly journals Digital Tolerence

2010 ◽  
Vol 132 (07) ◽  
pp. 32-34 ◽  
Author(s):  
Jean Thilmany
Keyword(s):  
Cultural Change ◽  
Computer Aided Design ◽  
Geometric Dimension ◽  
Coordinate Measuring Machine ◽  
Time To Market ◽  
Model Based ◽  
Inspection Process ◽  
Engineering Drawings ◽  
Measuring Machine ◽  
Aided Design

This article demonstrates the use of model-based definition (MBD), which can lead to improve productivity and reduce time-to-market. MBD is a method of annotating 3D computer-aided design models with geometric and tolerancing information. With Boeing moving to model-based definition, members of industry have approached the team in Montreal about investigating MBD’s usefulness. Experts believe that the MBD format, if widely adopted, would have implications for inspection. The part would be inspected against the tolerances contained within the CAD model rather than against the 2D engineering drawings, and that would speed the process and potentially make it even more accurate. The cultural change that will have to take place at most engineering companies will be difficult to tackle, and engineering and manufacturing managers know this. A model-based inspection software is being developed to read geometric, dimension, and tolerance information attached to a solid model. This will minimize operator input during development of coordinate measuring machine programs and improve the accuracy and integrity of the inspection process.

Analysis of Jansen Walking Mechanism Using CAD

2010 ◽  
Vol 166-167 ◽  
pp. 297-302 ◽  
Author(s):  
Florina Moldovan ◽  
Valer Dolga
Keyword(s):  
Design Process ◽  
Computer Aided Design ◽  
Walking Robots ◽  
Walking Robot ◽  
Short Term ◽  
Computer Aided ◽  
New Type ◽  
Walking Mechanism ◽  
Aided Design ◽  
Competitive Products

In this article is presented a short classification for walking robots that are based on leg locomotion and the main objectives that walking robots designers must achieve. The leg configuration of the walking robot is essential for obtaining a stable motion. Computer aided design process offers certain advantages for designers who attend to realize competitive products with fewer errors and in a short term. The aim of this article is to present the graphical results of the kinematic analysis of a new type of walking mechanism designed by Dutch physicist and sculptor Theo Jansen using Pro Engineer program and SAM, in order to compare the results.

Towards Combining Digitization Techniques in the Generation of Reverse Engineering Data Sets

1999 ◽  
Author(s):  
C. J. Rolls ◽  
W. ElMaraghy ◽  
H. ElMaraghy
Keyword(s):  
Reverse Engineering ◽  
Computer Aided Design ◽  
Laser Scanning ◽  
Single Point ◽  
Laser Scanner ◽  
Coordinate Measuring Machine ◽  
Industrial Applications ◽  
Data Sets ◽  
Error Characterization ◽  
Measuring Machine

Abstract Reverse engineering (RE), may be defined as the process of generating computer aided design models (CAD) from existing or prototype parts. The process has been used for many years in industry. It has markedly increased in implementation in the past few years, primarily due to the introduction of rapid part digitization technologies. Current industrial applications include CAD model construction from artisan geometry, such as in automotive body styling, the generation of custom fits to human surfaces, and quality control. This paper summarizes the principles of operation behind many commercially available part digitization technologies, and discusses techniques involved in part digitization using a coordinate measuring machine (CMM) and laser scanner. An overall error characterization of the laser scanning digitization process is presented for a particular scanner. This is followed by a discussion of the merits and considerations involved in generating combined data sets with characteristics indicative of the design intent of specific part features. Issues in facilitating the assembly, or registration, of the different types of data into a single point set are discussed.

Computer Aided Design of a New Universal Clamping Mechanism

2014 ◽  
Vol 597 ◽  
pp. 417-420
Author(s):  
Jeremy Zheng Li
Keyword(s):  
3D Modeling ◽  
Computer Aided Design ◽  
High Speed ◽  
Manufacturing Industry ◽  
Cost Effective ◽  
Geometrical Shape ◽  
Automated Production ◽  
Computer Aided ◽  
New Type ◽  
Aided Design

The tooling and fixture play important roles in manufacturing and production. It affects both product quality and quantity. Better tooling and fixture can also promote cost-effective manufacturing process. This paper introduces a new type of universal clamping mechanism based on computer-aided 3D modeling, engineering structural analysis, and prototype testing. It can be applied to easily and reliably clamp different geometrical shape of work pieces per user requirements. This new clamping mechanism, with less moving components, can assist manufacturing industry for high speed production, easy part handling, precise clamping, and lower tooling cost. Keywords: Computer-aided design, automated production, 3D modeling, cost-effective, high speed manufacturing, engineering analysis, optimization, efficient;

Error Modeling and Analysis of Articulated Arm Coordinate Measuring Machines

2013 ◽  
Vol 798-799 ◽  
pp. 464-467
Author(s):  
Jian Lu ◽  
Guan Bin Gao ◽  
Hui Ping Yang
Keyword(s):  
Kinematic Model ◽  
Coordinate Measuring Machine ◽  
Calibration Method ◽  
Error Model ◽  
Error Modeling ◽  
Modeling And Analysis ◽  
Low Weight ◽  
New Type ◽  
Measuring Machine ◽  
Value Decomposition

The Articulated Arm Coordinate Measuring Machine (AACMM) is a new type of non-orthogonal system precision instrument with the advantages of large measuring range, small volume, low weight and portability. To improve the measurement accuracy of AACMMs, an error analysis and calibration method for AACMMs is proposed. The kinematic model of the AACMM was established with D-H model, and then the error model of the AACMM was established on the basis of kinematic model with total differential transforming method and the singular value decomposition of Jacobian matrix and the decomposition of orthogonal matrix elementary row transform. Finally, the error model was validated by position error residual calculation. The error model provides a theoretical foundation for calibration and compensation of the AACMM.

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