Browse Prior Art Database

Algorithms for Model-Driven Mechanical Part Inspection

IP.com Disclosure Number: IPCOM000148754D
Original Publication Date: 1984-Nov-28
Included in the Prior Art Database: 2007-Mar-30
Document File: 26 page(s) / 1M

Publishing Venue

Software Patent Institute

Related People

Canny, John F.: AUTHOR [+2]

Abstract

28 November 1984 John F. Canny

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 6% of the total text.

Page 1 of 26

RC 10505 (f48869) 12/13/84

Computer Science 21 pages

Algorithms for Model-Driven Mechanical Part

Inspection

28 November 1984

John F. Canny

Industrial Machine Vision Project

Manufacturing Research Center

IBM Thomas J. Watson Research Center

Dimensional inspection of three-dimensional (3D) mechanical parts is a ubiquitous problem in man- ufacturing. By using a computer-controlled vision/robot system, the gathering of 3D data and in- terpretation in terms of specified tolerances can be automated; this, however, leaves the considerable problem of generating the appropriate vision and robot programs to inspect each part. This paper addresses two major subproblems that must be solved if inspection programs are to be generated automatically:

1. How can dimension and tolerancing information, along with nominal part geometry, be repres- ented to a computer?

2. From what directions can a vision system observe a part in order to see (or illuminate) a speci- fied feature?

This work was done while the author was a visiting graduating student in 1983. The author's current address is: M.I.T. Artificial Intelligence Laboratory, 545 Technology Square, Cambridge, MA, 02139.

[This page contains 1 picture or other non-text object]

Page 2 of 26

[This page contains 1 picture or other non-text object]

Page 3 of 26

CONTENTS

Introduction ................................................................... 1
A Simple Tolerancing Scheme for GDP ..............................................

3

Representation of Tolerances ..................................................... 3
Input of Tolerance Information .................................................... 5
Specific Examples of Toleranced Primitives ........................................... 6

Cuboids ................................................................... 6 ..................................................................

Cylinders 7

 Lamina 10 Tolerance Hierarchy and Merging ................................................ 10

12

Computation of the Umbra and Penumbra .......................................... 14
Penumbra of a Convex Face relative to a Convex Light Source .......................... 16

Summary and Conclusions ...................................................... -20

\

References .................................................................. 21

...................................................................

Planning Camera or Light Source Positions ..........................................

Contents

.....- ...-- ..

[This page contains 1 picture or other non-text object]

Page 4 of 26

List of Illustrations

...............................................

Figure 1 . Definition of Dimensions 4 Figure 2 . Tolerancing the Dimensions of a Cuboid ................................... 7

..................................

Figure 3 . Tolerancing the Dimensions of a C...